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Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/RCU/00-INDEX | 2 | ||||
| -rw-r--r-- | Documentation/RCU/trace.txt | 413 | ||||
| -rw-r--r-- | Documentation/arm/pxa/mfp.txt | 286 | ||||
| -rw-r--r-- | Documentation/block/biodoc.txt | 6 | ||||
| -rw-r--r-- | Documentation/dvb/technisat.txt | 69 | ||||
| -rw-r--r-- | Documentation/fb/pxafb.txt | 92 | ||||
| -rw-r--r-- | Documentation/lguest/lguest.c | 66 | ||||
| -rw-r--r-- | Documentation/lockstat.txt | 51 | ||||
| -rw-r--r-- | Documentation/video4linux/API.html | 43 | ||||
| -rw-r--r-- | Documentation/video4linux/CARDLIST.bttv | 7 | ||||
| -rw-r--r-- | Documentation/video4linux/CARDLIST.cx23885 | 1 | ||||
| -rw-r--r-- | Documentation/video4linux/CARDLIST.cx88 | 5 | ||||
| -rw-r--r-- | Documentation/video4linux/CARDLIST.em28xx | 9 | ||||
| -rw-r--r-- | Documentation/video4linux/CARDLIST.saa7134 | 3 | ||||
| -rw-r--r-- | Documentation/video4linux/README.cx88 | 8 | ||||
| -rw-r--r-- | Documentation/video4linux/gspca.txt | 19 | ||||
| -rw-r--r-- | Documentation/video4linux/v4l2-framework.txt | 520 |
17 files changed, 1490 insertions, 110 deletions
diff --git a/Documentation/RCU/00-INDEX b/Documentation/RCU/00-INDEX index 461481dfb7c..7dc0695a8f9 100644 --- a/Documentation/RCU/00-INDEX +++ b/Documentation/RCU/00-INDEX @@ -16,6 +16,8 @@ RTFP.txt - List of RCU papers (bibliography) going back to 1980. torture.txt - RCU Torture Test Operation (CONFIG_RCU_TORTURE_TEST) +trace.txt + - CONFIG_RCU_TRACE debugfs files and formats UP.txt - RCU on Uniprocessor Systems whatisRCU.txt diff --git a/Documentation/RCU/trace.txt b/Documentation/RCU/trace.txt new file mode 100644 index 00000000000..068848240a8 --- /dev/null +++ b/Documentation/RCU/trace.txt @@ -0,0 +1,413 @@ +CONFIG_RCU_TRACE debugfs Files and Formats + + +The rcupreempt and rcutree implementations of RCU provide debugfs trace +output that summarizes counters and state. This information is useful for +debugging RCU itself, and can sometimes also help to debug abuses of RCU. +Note that the rcuclassic implementation of RCU does not provide debugfs +trace output. + +The following sections describe the debugfs files and formats for +preemptable RCU (rcupreempt) and hierarchical RCU (rcutree). + + +Preemptable RCU debugfs Files and Formats + +This implementation of RCU provides three debugfs files under the +top-level directory RCU: rcu/rcuctrs (which displays the per-CPU +counters used by preemptable RCU) rcu/rcugp (which displays grace-period +counters), and rcu/rcustats (which internal counters for debugging RCU). + +The output of "cat rcu/rcuctrs" looks as follows: + +CPU last cur F M + 0 5 -5 0 0 + 1 -1 0 0 0 + 2 0 1 0 0 + 3 0 1 0 0 + 4 0 1 0 0 + 5 0 1 0 0 + 6 0 2 0 0 + 7 0 -1 0 0 + 8 0 1 0 0 +ggp = 26226, state = waitzero + +The per-CPU fields are as follows: + +o "CPU" gives the CPU number. Offline CPUs are not displayed. + +o "last" gives the value of the counter that is being decremented + for the current grace period phase. In the example above, + the counters sum to 4, indicating that there are still four + RCU read-side critical sections still running that started + before the last counter flip. + +o "cur" gives the value of the counter that is currently being + both incremented (by rcu_read_lock()) and decremented (by + rcu_read_unlock()). In the example above, the counters sum to + 1, indicating that there is only one RCU read-side critical section + still running that started after the last counter flip. + +o "F" indicates whether RCU is waiting for this CPU to acknowledge + a counter flip. In the above example, RCU is not waiting on any, + which is consistent with the state being "waitzero" rather than + "waitack". + +o "M" indicates whether RCU is waiting for this CPU to execute a + memory barrier. In the above example, RCU is not waiting on any, + which is consistent with the state being "waitzero" rather than + "waitmb". + +o "ggp" is the global grace-period counter. + +o "state" is the RCU state, which can be one of the following: + + o "idle": there is no grace period in progress. + + o "waitack": RCU just incremented the global grace-period + counter, which has the effect of reversing the roles of + the "last" and "cur" counters above, and is waiting for + all the CPUs to acknowledge the flip. Once the flip has + been acknowledged, CPUs will no longer be incrementing + what are now the "last" counters, so that their sum will + decrease monotonically down to zero. + + o "waitzero": RCU is waiting for the sum of the "last" counters + to decrease to zero. + + o "waitmb": RCU is waiting for each CPU to execute a memory + barrier, which ensures that instructions from a given CPU's + last RCU read-side critical section cannot be reordered + with instructions following the memory-barrier instruction. + +The output of "cat rcu/rcugp" looks as follows: + +oldggp=48870 newggp=48873 + +Note that reading from this file provokes a synchronize_rcu(). The +"oldggp" value is that of "ggp" from rcu/rcuctrs above, taken before +executing the synchronize_rcu(), and the "newggp" value is also the +"ggp" value, but taken after the synchronize_rcu() command returns. + + +The output of "cat rcu/rcugp" looks as follows: + +na=1337955 nl=40 wa=1337915 wl=44 da=1337871 dl=0 dr=1337871 di=1337871 +1=50989 e1=6138 i1=49722 ie1=82 g1=49640 a1=315203 ae1=265563 a2=49640 +z1=1401244 ze1=1351605 z2=49639 m1=5661253 me1=5611614 m2=49639 + +These are counters tracking internal preemptable-RCU events, however, +some of them may be useful for debugging algorithms using RCU. In +particular, the "nl", "wl", and "dl" values track the number of RCU +callbacks in various states. The fields are as follows: + +o "na" is the total number of RCU callbacks that have been enqueued + since boot. + +o "nl" is the number of RCU callbacks waiting for the previous + grace period to end so that they can start waiting on the next + grace period. + +o "wa" is the total number of RCU callbacks that have started waiting + for a grace period since boot. "na" should be roughly equal to + "nl" plus "wa". + +o "wl" is the number of RCU callbacks currently waiting for their + grace period to end. + +o "da" is the total number of RCU callbacks whose grace periods + have completed since boot. "wa" should be roughly equal to + "wl" plus "da". + +o "dr" is the total number of RCU callbacks that have been removed + from the list of callbacks ready to invoke. "dr" should be roughly + equal to "da". + +o "di" is the total number of RCU callbacks that have been invoked + since boot. "di" should be roughly equal to "da", though some + early versions of preemptable RCU had a bug so that only the + last CPU's count of invocations was displayed, rather than the + sum of all CPU's counts. + +o "1" is the number of calls to rcu_try_flip(). This should be + roughly equal to the sum of "e1", "i1", "a1", "z1", and "m1" + described below. In other words, the number of times that + the state machine is visited should be equal to the sum of the + number of times that each state is visited plus the number of + times that the state-machine lock acquisition failed. + +o "e1" is the number of times that rcu_try_flip() was unable to + acquire the fliplock. + +o "i1" is the number of calls to rcu_try_flip_idle(). + +o "ie1" is the number of times rcu_try_flip_idle() exited early + due to the calling CPU having no work for RCU. + +o "g1" is the number of times that rcu_try_flip_idle() decided + to start a new grace period. "i1" should be roughly equal to + "ie1" plus "g1". + +o "a1" is the number of calls to rcu_try_flip_waitack(). + +o "ae1" is the number of times that rcu_try_flip_waitack() found + that at least one CPU had not yet acknowledge the new grace period + (AKA "counter flip"). + +o "a2" is the number of time rcu_try_flip_waitack() found that + all CPUs had acknowledged. "a1" should be roughly equal to + "ae1" plus "a2". (This particular output was collected on + a 128-CPU machine, hence the smaller-than-usual fraction of + calls to rcu_try_flip_waitack() finding all CPUs having already + acknowledged.) + +o "z1" is the number of calls to rcu_try_flip_waitzero(). + +o "ze1" is the number of times that rcu_try_flip_waitzero() found + that not all of the old RCU read-side critical sections had + completed. + +o "z2" is the number of times that rcu_try_flip_waitzero() finds + the sum of the counters equal to zero, in other words, that + all of the old RCU read-side critical sections had completed. + The value of "z1" should be roughly equal to "ze1" plus + "z2". + +o "m1" is the number of calls to rcu_try_flip_waitmb(). + +o "me1" is the number of times that rcu_try_flip_waitmb() finds + that at least one CPU has not yet executed a memory barrier. + +o "m2" is the number of times that rcu_try_flip_waitmb() finds that + all CPUs have executed a memory barrier. + + +Hierarchical RCU debugfs Files and Formats + +This implementation of RCU provides three debugfs files under the +top-level directory RCU: rcu/rcudata (which displays fields in struct +rcu_data), rcu/rcugp (which displays grace-period counters), and +rcu/rcuhier (which displays the struct rcu_node hierarchy). + +The output of "cat rcu/rcudata" looks as follows: + +rcu: + 0 c=4011 g=4012 pq=1 pqc=4011 qp=0 rpfq=1 rp=3c2a dt=23301/73 dn=2 df=1882 of=0 ri=2126 ql=2 b=10 + 1 c=4011 g=4012 pq=1 pqc=4011 qp=0 rpfq=3 rp=39a6 dt=78073/1 dn=2 df=1402 of=0 ri=1875 ql=46 b=10 + 2 c=4010 g=4010 pq=1 pqc=4010 qp=0 rpfq=-5 rp=1d12 dt=16646/0 dn=2 df=3140 of=0 ri=2080 ql=0 b=10 + 3 c=4012 g=4013 pq=1 pqc=4012 qp=1 rpfq=3 rp=2b50 dt=21159/1 dn=2 df=2230 of=0 ri=1923 ql=72 b=10 + 4 c=4012 g=4013 pq=1 pqc=4012 qp=1 rpfq=3 rp=1644 dt=5783/1 dn=2 df=3348 of=0 ri=2805 ql=7 b=10 + 5 c=4012 g=4013 pq=0 pqc=4011 qp=1 rpfq=3 rp=1aac dt=5879/1 dn=2 df=3140 of=0 ri=2066 ql=10 b=10 + 6 c=4012 g=4013 pq=1 pqc=4012 qp=1 rpfq=3 rp=ed8 dt=5847/1 dn=2 df=3797 of=0 ri=1266 ql=10 b=10 + 7 c=4012 g=4013 pq=1 pqc=4012 qp=1 rpfq=3 rp=1fa2 dt=6199/1 dn=2 df=2795 of=0 ri=2162 ql=28 b=10 +rcu_bh: + 0 c=-268 g=-268 pq=1 pqc=-268 qp=0 rpfq=-145 rp=21d6 dt=23301/73 dn=2 df=0 of=0 ri=0 ql=0 b=10 + 1 c=-268 g=-268 pq=1 pqc=-268 qp=1 rpfq=-170 rp=20ce dt=78073/1 dn=2 df=26 of=0 ri=5 ql=0 b=10 + 2 c=-268 g=-268 pq=1 pqc=-268 qp=1 rpfq=-83 rp=fbd dt=16646/0 dn=2 df=28 of=0 ri=4 ql=0 b=10 + 3 c=-268 g=-268 pq=1 pqc=-268 qp=0 rpfq=-105 rp=178c dt=21159/1 dn=2 df=28 of=0 ri=2 ql=0 b=10 + 4 c=-268 g=-268 pq=1 pqc=-268 qp=1 rpfq=-30 rp=b54 dt=5783/1 dn=2 df=32 of=0 ri=0 ql=0 b=10 + 5 c=-268 g=-268 pq=1 pqc=-268 qp=1 rpfq=-29 rp=df5 dt=5879/1 dn=2 df=30 of=0 ri=3 ql=0 b=10 + 6 c=-268 g=-268 pq=1 pqc=-268 qp=1 rpfq=-28 rp=788 dt=5847/1 dn=2 df=32 of=0 ri=0 ql=0 b=10 + 7 c=-268 g=-268 pq=1 pqc=-268 qp=1 rpfq=-53 rp=1098 dt=6199/1 dn=2 df=30 of=0 ri=3 ql=0 b=10 + +The first section lists the rcu_data structures for rcu, the second for +rcu_bh. Each section has one line per CPU, or eight for this 8-CPU system. +The fields are as follows: + +o The number at the beginning of each line is the CPU number. + CPUs numbers followed by an exclamation mark are offline, + but have been online at least once since boot. There will be + no output for CPUs that have never been online, which can be + a good thing in the surprisingly common case where NR_CPUS is + substantially larger than the number of actual CPUs. + +o "c" is the count of grace periods that this CPU believes have + completed. CPUs in dynticks idle mode may lag quite a ways + behind, for example, CPU 4 under "rcu" above, which has slept + through the past 25 RCU grace periods. It is not unusual to + see CPUs lagging by thousands of grace periods. + +o "g" is the count of grace periods that this CPU believes have + started. Again, CPUs in dynticks idle mode may lag behind. + If the "c" and "g" values are equal, this CPU has already + reported a quiescent state for the last RCU grace period that + it is aware of, otherwise, the CPU believes that it owes RCU a + quiescent state. + +o "pq" indicates that this CPU has passed through a quiescent state + for the current grace period. It is possible for "pq" to be + "1" and "c" different than "g", which indicates that although + the CPU has passed through a quiescent state, either (1) this + CPU has not yet reported that fact, (2) some other CPU has not + yet reported for this grace period, or (3) both. + +o "pqc" indicates which grace period the last-observed quiescent + state for this CPU corresponds to. This is important for handling + the race between CPU 0 reporting an extended dynticks-idle + quiescent state for CPU 1 and CPU 1 suddenly waking up and + reporting its own quiescent state. If CPU 1 was the last CPU + for the current grace period, then the CPU that loses this race + will attempt to incorrectly mark CPU 1 as having checked in for + the next grace period! + +o "qp" indicates that RCU still expects a quiescent state from + this CPU. + +o "rpfq" is the number of rcu_pending() calls on this CPU required + to induce this CPU to invoke force_quiescent_state(). + +o "rp" is low-order four hex digits of the count of how many times + rcu_pending() has been invoked on this CPU. + +o "dt" is the current value of the dyntick counter that is incremented + when entering or leaving dynticks idle state, either by the + scheduler or by irq. The number after the "/" is the interrupt + nesting depth when in dyntick-idle state, or one greater than + the interrupt-nesting depth otherwise. + + This field is displayed only for CONFIG_NO_HZ kernels. + +o "dn" is the current value of the dyntick counter that is incremented + when entering or leaving dynticks idle state via NMI. If both + the "dt" and "dn" values are even, then this CPU is in dynticks + idle mode and may be ignored by RCU. If either of these two + counters is odd, then RCU must be alert to the possibility of + an RCU read-side critical section running on this CPU. + + This field is displayed only for CONFIG_NO_HZ kernels. + +o "df" is the number of times that some other CPU has forced a + quiescent state on behalf of this CPU due to this CPU being in + dynticks-idle state. + + This field is displayed only for CONFIG_NO_HZ kernels. + +o "of" is the number of times that some other CPU has forced a + quiescent state on behalf of this CPU due to this CPU being + offline. In a perfect world, this might neve happen, but it + turns out that offlining and onlining a CPU can take several grace + periods, and so there is likely to be an extended period of time + when RCU believes that the CPU is online when it really is not. + Please note that erring in the other direction (RCU believing a + CPU is offline when it is really alive and kicking) is a fatal + error, so it makes sense to err conservatively. + +o "ri" is the number of times that RCU has seen fit to send a + reschedule IPI to this CPU in order to get it to report a + quiescent state. + +o "ql" is the number of RCU callbacks currently residing on + this CPU. This is the total number of callbacks, regardless + of what state they are in (new, waiting for grace period to + start, waiting for grace period to end, ready to invoke). + +o "b" is the batch limit for this CPU. If more than this number + of RCU callbacks is ready to invoke, then the remainder will + be deferred. + + +The output of "cat rcu/rcugp" looks as follows: + +rcu: completed=33062 gpnum=33063 +rcu_bh: completed=464 gpnum=464 + +Again, this output is for both "rcu" and "rcu_bh". The fields are +taken from the rcu_state structure, and are as follows: + +o "completed" is the number of grace periods that have completed. + It is comparable to the "c" field from rcu/rcudata in that a + CPU whose "c" field matches the value of "completed" is aware + that the corresponding RCU grace period has completed. + +o "gpnum" is the number of grace periods that have started. It is + comparable to the "g" field from rcu/rcudata in that a CPU + whose "g" field matches the value of "gpnum" is aware that the + corresponding RCU grace period has started. + + If these two fields are equal (as they are for "rcu_bh" above), + then there is no grace period in progress, in other words, RCU + is idle. On the other hand, if the two fields differ (as they + do for "rcu" above), then an RCU grace period is in progress. + + +The output of "cat rcu/rcuhier" looks as follows, with very long lines: + +c=6902 g=6903 s=2 jfq=3 j=72c7 nfqs=13142/nfqsng=0(13142) fqlh=6 +1/1 0:127 ^0 +3/3 0:35 ^0 0/0 36:71 ^1 0/0 72:107 ^2 0/0 108:127 ^3 +3/3f 0:5 ^0 2/3 6:11 ^1 0/0 12:17 ^2 0/0 18:23 ^3 0/0 24:29 ^4 0/0 30:35 ^5 0/0 36:41 ^0 0/0 42:47 ^1 0/0 48:53 ^2 0/0 54:59 ^3 0/0 60:65 ^4 0/0 66:71 ^5 0/0 72:77 ^0 0/0 78:83 ^1 0/0 84:89 ^2 0/0 90:95 ^3 0/0 96:101 ^4 0/0 102:107 ^5 0/0 108:113 ^0 0/0 114:119 ^1 0/0 120:125 ^2 0/0 126:127 ^3 +rcu_bh: +c=-226 g=-226 s=1 jfq=-5701 j=72c7 nfqs=88/nfqsng=0(88) fqlh=0 +0/1 0:127 ^0 +0/3 0:35 ^0 0/0 36:71 ^1 0/0 72:107 ^2 0/0 108:127 ^3 +0/3f 0:5 ^0 0/3 6:11 ^1 0/0 12:17 ^2 0/0 18:23 ^3 0/0 24:29 ^4 0/0 30:35 ^5 0/0 36:41 ^0 0/0 42:47 ^1 0/0 48:53 ^2 0/0 54:59 ^3 0/0 60:65 ^4 0/0 66:71 ^5 0/0 72:77 ^0 0/0 78:83 ^1 0/0 84:89 ^2 0/0 90:95 ^3 0/0 96:101 ^4 0/0 102:107 ^5 0/0 108:113 ^0 0/0 114:119 ^1 0/0 120:125 ^2 0/0 126:127 ^3 + +This is once again split into "rcu" and "rcu_bh" portions. The fields are +as follows: + +o "c" is exactly the same as "completed" under rcu/rcugp. + +o "g" is exactly the same as "gpnum" under rcu/rcugp. + +o "s" is the "signaled" state that drives force_quiescent_state()'s + state machine. + +o "jfq" is the number of jiffies remaining for this grace period + before force_quiescent_state() is invoked to help push things + along. Note that CPUs in dyntick-idle mode thoughout the grace + period will not report on their own, but rather must be check by + some other CPU via force_quiescent_state(). + +o "j" is the low-order four hex digits of the jiffies counter. + Yes, Paul did run into a number of problems that turned out to + be due to the jiffies counter no longer counting. Why do you ask? + +o "nfqs" is the number of calls to force_quiescent_state() since + boot. + +o "nfqsng" is the number of useless calls to force_quiescent_state(), + where there wasn't actually a grace period active. This can + happen due to races. The number in parentheses is the difference + between "nfqs" and "nfqsng", or the number of times that + force_quiescent_state() actually did some real work. + +o "fqlh" is the number of calls to force_quiescent_state() that + exited immediately (without even being counted in nfqs above) + due to contention on ->fqslock. + +o Each element of the form "1/1 0:127 ^0" represents one struct + rcu_node. Each line represents one level of the hierarchy, from + root to leaves. It is best to think of the rcu_data structures + as forming yet another level after the leaves. Note that there + might be either one, two, or three levels of rcu_node structures, + depending on the relationship between CONFIG_RCU_FANOUT and + CONFIG_NR_CPUS. + + o The numbers separated by the "/" are the qsmask followed + by the qsmaskinit. The qsmask will have one bit + set for each entity in the next lower level that + has not yet checked in for the current grace period. + The qsmaskinit will have one bit for each entity that is + currently expected to check in during each grace period. + The value of qsmaskinit is assigned to that of qsmask + at the beginning of each grace period. + + For example, for "rcu", the qsmask of the first entry + of the lowest level is 0x14, meaning that we are still + waiting for CPUs 2 and 4 to check in for the current + grace period. + + o The numbers separated by the ":" are the range of CPUs + served by this struct rcu_node. This can be helpful + in working out how the hierarchy is wired together. + + For example, the first entry at the lowest level shows + "0:5", indicating that it covers CPUs 0 through 5. + + o The number after the "^" indicates the bit in the + next higher level rcu_node structure that this + rcu_node structure corresponds to. + + For example, the first entry at the lowest level shows + "^0", indicating that it corresponds to bit zero in + the first entry at the middle level. diff --git a/Documentation/arm/pxa/mfp.txt b/Documentation/arm/pxa/mfp.txt new file mode 100644 index 00000000000..a179e5bc02c --- /dev/null +++ b/Documentation/arm/pxa/mfp.txt @@ -0,0 +1,286 @@ + MFP Configuration for PXA2xx/PXA3xx Processors + + Eric Miao <eric.miao@marvell.com> + +MFP stands for Multi-Function Pin, which is the pin-mux logic on PXA3xx and +later PXA series processors. This document describes the existing MFP API, +and how board/platform driver authors could make use of it. + + Basic Concept +=============== + +Unlike the GPIO alternate function settings on PXA25x and PXA27x, a new MFP +mechanism is introduced from PXA3xx to completely move the pin-mux functions +out of the GPIO controller. In addition to pin-mux configurations, the MFP +also controls the low power state, driving strength, pull-up/down and event +detection of each pin. Below is a diagram of internal connections between +the MFP logic and the remaining SoC peripherals: + + +--------+ + | |--(GPIO19)--+ + | GPIO | | + | |--(GPIO...) | + +--------+ | + | +---------+ + +--------+ +------>| | + | PWM2 |--(PWM_OUT)-------->| MFP | + +--------+ +------>| |-------> to external PAD + | +---->| | + +--------+ | | +-->| | + | SSP2 |---(TXD)----+ | | +---------+ + +--------+ | | + | | + +--------+ | | + | Keypad |--(MKOUT4)----+ | + +--------+ | + | + +--------+ | + | UART2 |---(TXD)--------+ + +--------+ + +NOTE: the external pad is named as MFP_PIN_GPIO19, it doesn't necessarily +mean it's dedicated for GPIO19, only as a hint that internally this pin +can be routed from GPIO19 of the GPIO controller. + +To better understand the change from PXA25x/PXA27x GPIO alternate function +to this new MFP mechanism, here are several key points: + + 1. GPIO controller on PXA3xx is now a dedicated controller, same as other + internal controllers like PWM, SSP and UART, with 128 internal signals + which can be routed to external through one or more MFPs (e.g. GPIO<0> + can be routed through either MFP_PIN_GPIO0 as well as MFP_PIN_GPIO0_2, + see arch/arm/mach-pxa/mach/include/mfp-pxa300.h) + + 2. Alternate function configuration is removed from this GPIO controller, + the remaining functions are pure GPIO-specific, i.e. + + - GPIO signal level control + - GPIO direction control + - GPIO level change detection + + 3. Low power state for each pin is now controlled by MFP, this means the + PGSRx registers on PXA2xx are now useless on PXA3xx + + 4. Wakeup detection is now controlled by MFP, PWER does not control the + wakeup from GPIO(s) any more, depending on the sleeping state, ADxER + (as defined in pxa3xx-regs.h) controls the wakeup from MFP + +NOTE: with such a clear separation of MFP and GPIO, by GPIO<xx> we normally +mean it is a GPIO signal, and by MFP<xxx> or pin xxx, we mean a physical +pad (or ball). + + MFP API Usage +=============== + +For board code writers, here are some guidelines: + +1. include ONE of the following header files in your <board>.c: + + - #include <mach/mfp-pxa25x.h> + - #include <mach/mfp-pxa27x.h> + - #include <mach/mfp-pxa300.h> + - #include <mach/mfp-pxa320.h> + - #include <mach/mfp-pxa930.h> + + NOTE: only one file in your <board>.c, depending on the processors used, + because pin configuration definitions may conflict in these file (i.e. + same name, different meaning and settings on different processors). E.g. + for zylonite platform, which support both PXA300/PXA310 and PXA320, two + separate files are introduced: zylonite_pxa300.c and zylonite_pxa320.c + (in addition to handle MFP configuration differences, they also handle + the other differences between the two combinations). + + NOTE: PXA300 and PXA310 are almost identical in pin configurations (with + PXA310 supporting some additional ones), thus the difference is actually + covered in a single mfp-pxa300.h. + +2. prepare an array for the initial pin configurations, e.g.: + + static unsigned long mainstone_pin_config[] __initdata = { + /* Chip Select */ + GPIO15_nCS_1, + + /* LCD - 16bpp Active TFT */ + GPIOxx_TFT_LCD_16BPP, + GPIO16_PWM0_OUT, /* Backlight */ + + /* MMC */ + GPIO32_MMC_CLK, + GPIO112_MMC_CMD, + GPIO92_MMC_DAT_0, + GPIO109_MMC_DAT_1, + GPIO110_MMC_DAT_2, + GPIO111_MMC_DAT_3, + + ... + + /* GPIO */ + GPIO1_GPIO | WAKEUP_ON_EDGE_BOTH, + }; + + a) once the pin configurations are passed to pxa{2xx,3xx}_mfp_config(), + and written to the actual registers, they are useless and may discard, + adding '__initdata' will help save some additional bytes here. + + b) when there is only one possible pin configurations for a component, + some simplified definitions can be used, e.g. GPIOxx_TFT_LCD_16BPP on + PXA25x and PXA27x processors + + c) if by board design, a pin can be configured to wake up the system + from low power state, it can be 'OR'ed with any of: + + WAKEUP_ON_EDGE_BOTH + WAKEUP_ON_EDGE_RISE + WAKEUP_ON_EDGE_FALL + WAKEUP_ON_LEVEL_HIGH - specifically for enabling of keypad GPIOs, + + to indicate that this pin has the capability of wake-up the system, + and on which edge(s). This, however, doesn't necessarily mean the + pin _will_ wakeup the system, it will only when set_irq_wake() is + invoked with the corresponding GPIO IRQ (GPIO_IRQ(xx) or gpio_to_irq()) + and eventually calls gpio_set_wake() for the actual register setting. + + d) although PXA3xx MFP supports edge detection on each pin, the + internal logic will only wakeup the system when those specific bits + in ADxER registers are set, which can be well mapped to the + corresponding peripheral, thus set_irq_wake() can be called with + the peripheral IRQ to enable the wakeup. + + + MFP on PXA3xx +=============== + +Every external I/O pad on PXA3xx (excluding those for special purpose) has +one MFP logic associated, and is controlled by one MFP register (MFPR). + +The MFPR has the following bit definitions (for PXA300/PXA310/PXA320): + + 31 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 + +-------------------------+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + | RESERVED |PS|PU|PD| DRIVE |SS|SD|SO|EC|EF|ER|--| AF_SEL | + +-------------------------+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + + Bit 3: RESERVED + Bit 4: EDGE_RISE_EN - enable detection of rising edge on this pin + Bit 5: EDGE_FALL_EN - enable detection of falling edge on this pin + Bit 6: EDGE_CLEAR - disable edge detection on this pin + Bit 7: SLEEP_OE_N - enable outputs during low power modes + Bit 8: SLEEP_DATA - output data on the pin during low power modes + Bit 9: SLEEP_SEL - selection control for low power modes signals + Bit 13: PULLDOWN_EN - enable the internal pull-down resistor on this pin + Bit 14: PULLUP_EN - enable the internal pull-up resistor on this pin + Bit 15: PULL_SEL - pull state controlled by selected alternate function + (0) or by PULL{UP,DOWN}_EN bits (1) + + Bit 0 - 2: AF_SEL - alternate function selection, 8 possibilities, from 0-7 + Bit 10-12: DRIVE - drive strength and slew rate + 0b000 - fast 1mA + 0b001 - fast 2mA + 0b002 - fast 3mA + 0b003 - fast 4mA + 0b004 - slow 6mA + 0b005 - fast 6mA + 0b006 - slow 10mA + 0b007 - fast 10mA + + MFP Design for PXA2xx/PXA3xx +============================== + +Due to the difference of pin-mux handling between PXA2xx and PXA3xx, a unified +MFP API is introduced to cover both series of processors. + +The basic idea of this design is to introduce definitions for all possible pin +configurations, these definitions are processor and platform independent, and +the actual API invoked to convert these definitions into register settings and +make them effective there-after. + + Files Involved + -------------- + + - arch/arm/mach-pxa/include/mach/mfp.h + + for + 1. Unified pin definitions - enum constants for all configurable pins + 2. processor-neutral bit definitions for a possible MFP configuration + + - arch/arm/mach-pxa/include/mach/mfp-pxa3xx.h + + for PXA3xx specific MFPR register bit definitions and PXA3xx common pin + configurations + + - arch/arm/mach-pxa/include/mach/mfp-pxa2xx.h + + for PXA2xx specific definitions and PXA25x/PXA27x common pin configurations + + - arch/arm/mach-pxa/include/mach/mfp-pxa25x.h + arch/arm/mach-pxa/include/mach/mfp-pxa27x.h + arch/arm/mach-pxa/include/mach/mfp-pxa300.h + arch/arm/mach-pxa/include/mach/mfp-pxa320.h + arch/arm/mach-pxa/include/mach/mfp-pxa930.h + + for processor specific definitions + + - arch/arm/mach-pxa/mfp-pxa3xx.c + - arch/arm/mach-pxa/mfp-pxa2xx.c + + for implementation of the pin configuration to take effect for the actual + processor. + + Pin Configuration + ----------------- + + The following comments are copied from mfp.h (see the actual source code + for most updated info) + + /* + * a possible MFP configuration is represented by a 32-bit integer + * + * bit 0.. 9 - MFP Pin Number (1024 Pins Maximum) + * bit 10..12 - Alternate Function Selection + * bit 13..15 - Drive Strength + * bit 16..18 - Low Power Mode State + * bit 19..20 - Low Power Mode Edge Detection + * bit 21..22 - Run Mode Pull State + * + * to facilitate the definition, the following macros are provided + * + * MFP_CFG_DEFAULT - default MFP configuration value, with + * alternate function = 0, + * drive strength = fast 3mA (MFP_DS03X) + * low power mode = default + * edge detection = none + * + * MFP_CFG - default MFPR value with alternate function + * MFP_CFG_DRV - default MFPR value with alternate function and + * pin drive strength + * MFP_CFG_LPM - default MFPR value with alternate function and + * low power mode + * MFP_CFG_X - default MFPR value with alternate function, + * pin drive strength and low power mode + */ + + Examples of pin configurations are: + + #define GPIO94_SSP3_RXD MFP_CFG_X(GPIO94, AF1, DS08X, FLOAT) + + which reads GPIO94 can be configured as SSP3_RXD, with alternate function + selection of 1, driving strength of 0b101, and a float state in low power + modes. + + NOTE: this is the default setting of this pin being configured as SSP3_RXD + which can be modified a bit in board code, though it is not recommended to + do so, simply because this default setting is usually carefully encoded, + and is supposed to work in most cases. + + Register Settings + ----------------- + + Register settings on PXA3xx for a pin configuration is actually very + straight-forward, most bits can be converted directly into MFPR value + in a easier way. Two sets of MFPR values are calculated: the run-time + ones and the low power mode ones, to allow different settings. + + The conversion from a generic pin configuration to the actual register + settings on PXA2xx is a bit complicated: many registers are involved, + including GAFRx, GPDRx, PGSRx, PWER, PKWR, PFER and PRER. Please see + mfp-pxa2xx.c for how the conversion is made. diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index 4dbb8be1c99..3c5434c83da 100644 --- a/Documentation/block/biodoc.txt +++ b/Documentation/block/biodoc.txt @@ -914,7 +914,7 @@ I/O scheduler, a.k.a. elevator, is implemented in two layers. Generic dispatch queue and specific I/O schedulers. Unless stated otherwise, elevator is used to refer to both parts and I/O scheduler to specific I/O schedulers. -Block layer implements generic dispatch queue in ll_rw_blk.c and elevator.c. +Block layer implements generic dispatch queue in block/*.c. The generic dispatch queue is responsible for properly ordering barrier requests, requeueing, handling non-fs requests and all other subtleties. @@ -926,8 +926,8 @@ be built inside the kernel. Each queue can choose different one and can also change to another one dynamically. A block layer call to the i/o scheduler follows the convention elv_xxx(). This -calls elevator_xxx_fn in the elevator switch (drivers/block/elevator.c). Oh, -xxx and xxx might not match exactly, but use your imagination. If an elevator +calls elevator_xxx_fn in the elevator switch (block/elevator.c). Oh, xxx +and xxx might not match exactly, but use your imagination. If an elevator doesn't implement a function, the switch does nothing or some minimal house keeping work. diff --git a/Documentation/dvb/technisat.txt b/Documentation/dvb/technisat.txt new file mode 100644 index 00000000000..cdf6ee4b2da --- /dev/null +++ b/Documentation/dvb/technisat.txt @@ -0,0 +1,69 @@ +How to set up the Technisat devices +=================================== + +1) Find out what device you have +================================ + +First start your linux box with a shipped kernel: +lspci -vvv for a PCI device (lsusb -vvv for an USB device) will show you for example: +02:0b.0 Network controller: Techsan Electronics Co Ltd B2C2 FlexCopII DVB chip / Technisat SkyStar2 DVB card (rev 02) + +dmesg | grep frontend may show you for example: +DVB: registering frontend 0 (Conexant CX24123/CX24109)... + +2) Kernel compilation: +====================== + +If the Technisat is the only TV device in your box get rid of unnecessary modules and check this one: +"Multimedia devices" => "Customise analog and hybrid tuner modules to build" +In this directory uncheck every driver which is activated there. + +Then please activate: +2a) Main module part: + +a.)"Multimedia devices" => "DVB/ATSC adapters" => "Technisat/B2C2 FlexcopII(b) and FlexCopIII adapters" +b.)"Multimedia devices" => "DVB/ATSC adapters" => "Technisat/B2C2 FlexcopII(b) and FlexCopIII adapters" => "Technisat/B2C2 Air/Sky/Cable2PC PCI" in case of a PCI card OR +c.)"Multimedia devices" => "DVB/ATSC adapters" => "Technisat/B2C2 FlexcopII(b) and FlexCopIII adapters" => "Technisat/B2C2 Air/Sky/Cable2PC USB" in case of an USB 1.1 adapter +d.)"Multimedia devices" => "DVB/ATSC adapters" => "Technisat/B2C2 FlexcopII(b) and FlexCopIII adapters" => "Enable debug for the B2C2 FlexCop drivers" +Notice: d.) is helpful for troubleshooting + +2b) Frontend module part: + +1.) Revision 2.3: +a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build" +b.)"Multimedia devices" => "Customise DVB frontends" => "Zarlink VP310/MT312/ZL10313 based" + +2.) Revision 2.6: +a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build" +b.)"Multimedia devices" => "Customise DVB frontends" => "ST STV0299 based" + +3.) Revision 2.7: +a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build" +b.)"Multimedia devices" => "Customise DVB frontends" => "Samsung S5H1420 based" +c.)"Multimedia devices" => "Customise DVB frontends" => "Integrant ITD1000 Zero IF tuner for DVB-S/DSS" +d.)"Multimedia devices" => "Customise DVB frontends" => "ISL6421 SEC controller" + +4.) Revision 2.8: +a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build" +b.)"Multimedia devices" => "Customise DVB frontends" => "Conexant CX24113/CX24128 tuner for DVB-S/DSS" +c.)"Multimedia devices" => "Customise DVB frontends" => "Conexant CX24123 based" +d.)"Multimedia devices" => "Customise DVB frontends" => "ISL6421 SEC controller" + +5.) DVB-T card: +a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build" +b.)"Multimedia devices" => "Customise DVB frontends" => "Zarlink MT352 based" + +6.) DVB-C card: +a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build" +b.)"Multimedia devices" => "Customise DVB frontends" => "ST STV0297 based" + +7.) ATSC card 1st generation: +a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build" +b.)"Multimedia devices" => "Customise DVB frontends" => "Broadcom BCM3510" + +8.) ATSC card 2nd generation: +a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build" +b.)"Multimedia devices" => "Customise DVB frontends" => "NxtWave Communications NXT2002/NXT2004 based" +c.)"Multimedia devices" => "Customise DVB frontends" => "LG Electronics LGDT3302/LGDT3303 based" + +Author: Uwe Bugla <uwe.bugla@gmx.de> December 2008 diff --git a/Documentation/fb/pxafb.txt b/Documentation/fb/pxafb.txt index db9b8500b43..d143a0a749f 100644 --- a/Documentation/fb/pxafb.txt +++ b/Documentation/fb/pxafb.txt @@ -5,9 +5,13 @@ The driver supports the following options, either via options=<OPTIONS> when modular or video=pxafb:<OPTIONS> when built in. For example: - modprobe pxafb options=mode:640x480-8,passive + modprobe pxafb options=vmem:2M,mode:640x480-8,passive or on the kernel command line - video=pxafb:mode:640x480-8,passive + video=pxafb:vmem:2M,mode:640x480-8,passive + +vmem: VIDEO_MEM_SIZE + Amount of video memory to allocate (can be suffixed with K or M + for kilobytes or megabytes) mode:XRESxYRES[-BPP] XRES == LCCR1_PPL + 1 @@ -52,3 +56,87 @@ outputen:POLARITY pixclockpol:POLARITY pixel clock polarity 0 => falling edge, 1 => rising edge + + +Overlay Support for PXA27x and later LCD controllers +==================================================== + + PXA27x and later processors support overlay1 and overlay2 on-top of the + base framebuffer (although under-neath the base is also possible). They + support palette and no-palette RGB formats, as well as YUV formats (only + available on overlay2). These overlays have dedicated DMA channels and + behave in a similar way as a framebuffer. + + However, there are some differences between these overlay framebuffers + and normal framebuffers, as listed below: + + 1. overlay can start at a 32-bit word aligned position within the base + framebuffer, which means they have a start (x, y). This information + is encoded into var->nonstd (no, var->xoffset and var->yoffset are + not for such purpose). + + 2. overlay framebuffer is allocated dynamically according to specified + 'struct fb_var_screeninfo', the amount is decided by: + + var->xres_virtual * var->yres_virtual * bpp + + bpp = 16 -- for RGB565 or RGBT555 + = 24 -- for YUV444 packed + = 24 -- for YUV444 planar + = 16 -- for YUV422 planar (1 pixel = 1 Y + 1/2 Cb + 1/2 Cr) + = 12 -- for YUV420 planar (1 pixel = 1 Y + 1/4 Cb + 1/4 Cr) + + NOTE: + + a. overlay does not support panning in x-direction, thus + var->xres_virtual will always be equal to var->xres + + b. line length of overlay(s) must be on a 32-bit word boundary, + for YUV planar modes, it is a requirement for the component + with minimum bits per pixel, e.g. for YUV420, Cr component + for one pixel is actually 2-bits, it means the line length + should be a multiple of 16-pixels + + c. starting horizontal position (XPOS) should start on a 32-bit + word boundary, otherwise the fb_check_var() will just fail. + + d. the rectangle of the overlay should be within the base plane, + otherwise fail + + Applications should follow the sequence below to operate an overlay + framebuffer: + + a. open("/dev/fb[1-2]", ...) + b. ioctl(fd, FBIOGET_VSCREENINFO, ...) + c. modify 'var' with desired parameters: + 1) var->xres and var->yres + 2) larger var->yres_virtual if more memory is required, + usually for double-buffering + 3) var->nonstd for starting (x, y) and color format + 4) var->{red, green, blue, transp} if RGB mode is to be used + d. ioctl(fd, FBIOPUT_VSCREENINFO, ...) + e. ioctl(fd, FBIOGET_FSCREENINFO, ...) + f. mmap + g. ... + + 3. for YUV planar formats, these are actually not supported within the + framebuffer framework, application has to take care of the offsets + and lengths of each component within the framebuffer. + + 4. var->nonstd is used to pass starting (x, y) position and color format, + the detailed bit fields are shown below: + + 31 23 20 10 0 + +-----------------+---+----------+----------+ + | ... unused ... |FOR| XPOS | YPOS | + +-----------------+---+----------+----------+ + + FOR - color format, as defined by OVERLAY_FORMAT_* in pxafb.h + 0 - RGB + 1 - YUV444 PACKED + 2 - YUV444 PLANAR + 3 - YUV422 PLANAR + 4 - YUR420 PLANAR + + XPOS - starting horizontal position + YPOS - starting vertical position diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index 804520633fc..f2dbbf3bdea 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -481,51 +481,6 @@ static unsigned long load_initrd(const char *name, unsigned long mem) /* We return the initrd size. */ return len; } - -/* Once we know how much memory we have we can construct simple linear page - * tables which set virtual == physical which will get the Guest far enough - * into the boot to create its own. - * - * We lay them out of the way, just below the initrd (which is why we need to - * know its size here). */ -static unsigned long setup_pagetables(unsigned long mem, - unsigned long initrd_size) -{ - unsigned long *pgdir, *linear; - unsigned int mapped_pages, i, linear_pages; - unsigned int ptes_per_page = getpagesize()/sizeof(void *); - - mapped_pages = mem/getpagesize(); - - /* Each PTE page can map ptes_per_page pages: how many do we need? */ - linear_pages = (mapped_pages + ptes_per_page-1)/ptes_per_page; - - /* We put the toplevel page directory page at the top of memory. */ - pgdir = from_guest_phys(mem) - initrd_size - getpagesize(); - - /* Now we use the next linear_pages pages as pte pages */ - linear = (void *)pgdir - linear_pages*getpagesize(); - - /* Linear mapping is easy: put every page's address into the mapping in - * order. PAGE_PRESENT contains the flags Present, Writable and - * Executable. */ - for (i = 0; i < mapped_pages; i++) - linear[i] = ((i * getpagesize()) | PAGE_PRESENT); - - /* The top level points to the linear page table pages above. */ - for (i = 0; i < mapped_pages; i += ptes_per_page) { - pgdir[i/ptes_per_page] - = ((to_guest_phys(linear) + i*sizeof(void *)) - | PAGE_PRESENT); - } - - verbose("Linear mapping of %u pages in %u pte pages at %#lx\n", - mapped_pages, linear_pages, to_guest_phys(linear)); - - /* We return the top level (guest-physical) address: the kernel needs - * to know where it is. */ - return to_guest_phys(pgdir); -} /*:*/ /* Simple routine to roll all the commandline arguments together with spaces @@ -548,13 +503,13 @@ static void concat(char *dst, char *args[]) /*L:185 This is where we actually tell the kernel to initialize the Guest. We * saw the arguments it expects when we looked at initialize() in lguest_user.c: - * the base of Guest "physical" memory, the top physical page to allow, the - * top level pagetable and the entry point for the Guest. */ -static int tell_kernel(unsigned long pgdir, unsigned long start) + * the base of Guest "physical" memory, the top physical page to allow and the + * entry point for the Guest. */ +static int tell_kernel(unsigned long start) { unsigned long args[] = { LHREQ_INITIALIZE, (unsigned long)guest_base, - guest_limit / getpagesize(), pgdir, start }; + guest_limit / getpagesize(), start }; int fd; verbose("Guest: %p - %p (%#lx)\n", @@ -1030,7 +985,7 @@ static void update_device_status(struct device *dev) /* Zero out the virtqueues. */ for (vq = dev->vq; vq; vq = vq->next) { memset(vq->vring.desc, 0, - vring_size(vq->config.num, getpagesize())); + vring_size(vq->config.num, LGUEST_VRING_ALIGN)); lg_last_avail(vq) = 0; } } else if (dev->desc->status & VIRTIO_CONFIG_S_FAILED) { @@ -1211,7 +1166,7 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs, void *p; /* First we need some memory for this virtqueue. */ - pages = (vring_size(num_descs, getpagesize()) + getpagesize() - 1) + pages = (vring_size(num_descs, LGUEST_VRING_ALIGN) + getpagesize() - 1) / getpagesize(); p = get_pages(pages); @@ -1228,7 +1183,7 @@ static void add_virtqueue(struct device *dev, unsigned int num_descs, vq->config.pfn = to_guest_phys(p) / getpagesize(); /* Initialize the vring. */ - vring_init(&vq->vring, num_descs, p, getpagesize()); + vring_init(&vq->vring, num_descs, p, LGUEST_VRING_ALIGN); /* Append virtqueue to this device's descriptor. We use * device_config() to get the end of the device's current virtqueues; @@ -1941,7 +1896,7 @@ int main(int argc, char *argv[]) { /* Memory, top-level pagetable, code startpoint and size of the * (optional) initrd. */ - unsigned long mem = 0, pgdir, start, initrd_size = 0; + unsigned long mem = 0, start, initrd_size = 0; /* Two temporaries and the /dev/lguest file descriptor. */ int i, c, lguest_fd; /* The boot information for the Guest. */ @@ -2040,9 +1995,6 @@ int main(int argc, char *argv[]) boot->hdr.type_of_loader = 0xFF; } - /* Set up the initial linear pagetables, starting below the initrd. */ - pgdir = setup_pagetables(mem, initrd_size); - /* The Linux boot header contains an "E820" memory map: ours is a * simple, single region. */ boot->e820_entries = 1; @@ -2064,7 +2016,7 @@ int main(int argc, char *argv[]) /* We tell the kernel to initialize the Guest: this returns the open * /dev/lguest file descriptor. */ - lguest_fd = tell_kernel(pgdir, start); + lguest_fd = tell_kernel(start); /* We clone off a thread, which wakes the Launcher whenever one of the * input file descriptors needs attention. We call this the Waker, and diff --git a/Documentation/lockstat.txt b/Documentation/lockstat.txt index 4ba4664ce5c..9cb9138f7a7 100644 --- a/Documentation/lockstat.txt +++ b/Documentation/lockstat.txt @@ -71,35 +71,50 @@ Look at the current lock statistics: # less /proc/lock_stat -01 lock_stat version 0.2 +01 lock_stat version 0.3 02 ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 03 class name con-bounces contentions waittime-min waittime-max waittime-total acq-bounces acquisitions holdtime-min holdtime-max holdtime-total 04 ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 05 -06 &inode->i_data.tree_lock-W: 15 21657 0.18 1093295.30 11547131054.85 58 10415 0.16 87.51 6387.60 -07 &inode->i_data.tree_lock-R: 0 0 0.00 0.00 0.00 23302 231198 0.25 8.45 98023.38 -08 -------------------------- -09 &inode->i_data.tree_lock 0 [<ffffffff8027c08f>] add_to_page_cache+0x5f/0x190 -10 -11 ............................................................................................................................................................................................... -12 -13 dcache_lock: 1037 1161 0.38 45.32 774.51 6611 243371 0.15 306.48 77387.24 -14 ----------- -15 dcache_lock 180 [<ffffffff802c0d7e>] sys_getcwd+0x11e/0x230 -16 dcache_lock 165 [<ffffffff802c002a>] d_alloc+0x15a/0x210 -17 dcache_lock 33 [<ffffffff8035818d>] _atomic_dec_and_lock+0x4d/0x70 -18 dcache_lock 1 [<ffffffff802beef8>] shrink_dcache_parent+0x18/0x130 +06 &mm->mmap_sem-W: 233 538 18446744073708 22924.27 607243.51 1342 45806 1.71 8595.89 1180582.34 +07 &mm->mmap_sem-R: 205 587 18446744073708 28403.36 731975.00 1940 412426 0.58 187825.45 6307502.88 +08 --------------- +09 &mm->mmap_sem 487 [<ffffffff8053491f>] do_page_fault+0x466/0x928 +10 &mm->mmap_sem 179 [<ffffffff802a6200>] sys_mprotect+0xcd/0x21d +11 &mm->mmap_sem 279 [<ffffffff80210a57>] sys_mmap+0x75/0xce +12 &mm->mmap_sem 76 [<ffffffff802a490b>] sys_munmap+0x32/0x59 +13 --------------- +14 &mm->mmap_sem 270 [<ffffffff80210a57>] sys_mmap+0x75/0xce +15 &mm->mmap_sem 431 [<ffffffff8053491f>] do_page_fault+0x466/0x928 +16 &mm->mmap_sem 138 [<ffffffff802a490b>] sys_munmap+0x32/0x59 +17 &mm->mmap_sem 145 [<ffffffff802a6200>] sys_mprotect+0xcd/0x21d +18 +19 ............................................................................................................................................................................................... +20 +21 dcache_lock: 621 623 0.52 118.26 1053.02 6745 91930 0.29 316.29 118423.41 +22 ----------- +23 dcache_lock 179 [<ffffffff80378274>] _atomic_dec_and_lock+0x34/0x54 +24 dcache_lock 113 [<ffffffff802cc17b>] d_alloc+0x19a/0x1eb +25 dcache_lock 99 [<ffffffff802ca0dc>] d_rehash+0x1b/0x44 +26 dcache_lock 104 [<ffffffff802cbca0>] d_instantiate+0x36/0x8a +27 ----------- +28 dcache_lock 192 [<ffffffff80378274>] _atomic_dec_and_lock+0x34/0x54 +29 dcache_lock 98 [<ffffffff802ca0dc>] d_rehash+0x1b/0x44 +30 dcache_lock 72 [<ffffffff802cc17b>] d_alloc+0x19a/0x1eb +31 dcache_lock 112 [<ffffffff802cbca0>] d_instantiate+0x36/0x8a This excerpt shows the first two lock class statistics. Line 01 shows the output version - each time the format changes this will be updated. Line 02-04 -show the header with column descriptions. Lines 05-10 and 13-18 show the actual +show the header with column descriptions. Lines 05-18 and 20-31 show the actual statistics. These statistics come in two parts; the actual stats separated by a -short separator (line 08, 14) from the contention points. +short separator (line 08, 13) from the contention points. -The first lock (05-10) is a read/write lock, and shows two lines above the +The first lock (05-18) is a read/write lock, and shows two lines above the short separator. The contention points don't match the column descriptors, -they have two: contentions and [<IP>] symbol. +they have two: contentions and [<IP>] symbol. The second set of contention +points are the points we're contending with. +The integer part of the time values is in us. View the top contending locks: diff --git a/Documentation/video4linux/API.html b/Documentation/video4linux/API.html index afbe9ae7ee9..d749d41f647 100644 --- a/Documentation/video4linux/API.html +++ b/Documentation/video4linux/API.html @@ -1,16 +1,27 @@ -<TITLE>V4L API</TITLE> -<H1>Video For Linux APIs</H1> -<table border=0> -<tr> -<td> -<A HREF=http://www.linuxtv.org/downloads/video4linux/API/V4L1_API.html> -V4L original API</a> -</td><td> -Obsoleted by V4L2 API -</td></tr><tr><td> -<A HREF=http://www.linuxtv.org/downloads/video4linux/API/V4L2_API> -V4L2 API</a> -</td><td> -Should be used for new projects -</td></tr> -</table> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"> + <head> + <meta content="text/html;charset=ISO-8859-2" http-equiv="Content-Type" /> + <title>V4L API</title> + </head> + <body> + <h1>Video For Linux APIs</h1> + <table border="0"> + <tr> + <td> + <a href="http://www.linuxtv.org/downloads/video4linux/API/V4L1_API.html">V4L original API</a> + </td> + <td> + Obsoleted by V4L2 API + </td> + </tr> + <tr> + <td> + <a href="http://www.linuxtv.org/downloads/video4linux/API/V4L2_API">V4L2 API</a> + </td> + <td>Should be used for new projects + </td> + </tr> + </table> + </body> +</html> diff --git a/Documentation/video4linux/CARDLIST.bttv b/Documentation/video4linux/CARDLIST.bttv index 60ba6683603..0d93fa1ac25 100644 --- a/Documentation/video4linux/CARDLIST.bttv +++ b/Documentation/video4linux/CARDLIST.bttv @@ -104,8 +104,8 @@ 103 -> Grand X-Guard / Trust 814PCI [0304:0102] 104 -> Nebula Electronics DigiTV [0071:0101] 105 -> ProVideo PV143 [aa00:1430,aa00:1431,aa00:1432,aa00:1433,aa03:1433] -106 -> PHYTEC VD-009-X1 MiniDIN (bt878) -107 -> PHYTEC VD-009-X1 Combi (bt878) +106 -> PHYTEC VD-009-X1 VD-011 MiniDIN (bt878) +107 -> PHYTEC VD-009-X1 VD-011 Combi (bt878) 108 -> PHYTEC VD-009 MiniDIN (bt878) 109 -> PHYTEC VD-009 Combi (bt878) 110 -> IVC-100 [ff00:a132] @@ -151,3 +151,6 @@ 150 -> Geovision GV-600 [008a:763c] 151 -> Kozumi KTV-01C 152 -> Encore ENL TV-FM-2 [1000:1801] +153 -> PHYTEC VD-012 (bt878) +154 -> PHYTEC VD-012-X1 (bt878) +155 -> PHYTEC VD-012-X2 (bt878) diff --git a/Documentation/video4linux/CARDLIST.cx23885 b/Documentation/video4linux/CARDLIST.cx23885 index 64823ccacd6..35ea130e989 100644 --- a/Documentation/video4linux/CARDLIST.cx23885 +++ b/Documentation/video4linux/CARDLIST.cx23885 @@ -11,3 +11,4 @@ 10 -> DViCO FusionHDTV7 Dual Express [18ac:d618] 11 -> DViCO FusionHDTV DVB-T Dual Express [18ac:db78] 12 -> Leadtek Winfast PxDVR3200 H [107d:6681] + 13 -> Compro VideoMate E650F [185b:e800] diff --git a/Documentation/video4linux/CARDLIST.cx88 b/Documentation/video4linux/CARDLIST.cx88 index a5227e308f4..0d08f1edcf6 100644 --- a/Documentation/video4linux/CARDLIST.cx88 +++ b/Documentation/video4linux/CARDLIST.cx88 @@ -2,7 +2,7 @@ 1 -> Hauppauge WinTV 34xxx models [0070:3400,0070:3401] 2 -> GDI Black Gold [14c7:0106,14c7:0107] 3 -> PixelView [1554:4811] - 4 -> ATI TV Wonder Pro [1002:00f8] + 4 -> ATI TV Wonder Pro [1002:00f8,1002:00f9] 5 -> Leadtek Winfast 2000XP Expert [107d:6611,107d:6613] 6 -> AverTV Studio 303 (M126) [1461:000b] 7 -> MSI TV-@nywhere Master [1462:8606] @@ -74,3 +74,6 @@ 73 -> TeVii S420 DVB-S [d420:9022] 74 -> Prolink Pixelview Global Extreme [1554:4976] 75 -> PROF 7300 DVB-S/S2 [B033:3033] + 76 -> SATTRADE ST4200 DVB-S/S2 [b200:4200] + 77 -> TBS 8910 DVB-S [8910:8888] + 78 -> Prof 6200 DVB-S [b022:3022] diff --git a/Documentation/video4linux/CARDLIST.em28xx b/Documentation/video4linux/CARDLIST.em28xx index 187cc48d092..75bded8a4aa 100644 --- a/Documentation/video4linux/CARDLIST.em28xx +++ b/Documentation/video4linux/CARDLIST.em28xx @@ -1,5 +1,5 @@ 0 -> Unknown EM2800 video grabber (em2800) [eb1a:2800] - 1 -> Unknown EM2750/28xx video grabber (em2820/em2840) [eb1a:2820,eb1a:2860,eb1a:2861,eb1a:2870,eb1a:2881,eb1a:2883] + 1 -> Unknown EM2750/28xx video grabber (em2820/em2840) [eb1a:2820,eb1a:2821,eb1a:2860,eb1a:2861,eb1a:2870,eb1a:2881,eb1a:2883] 2 -> Terratec Cinergy 250 USB (em2820/em2840) [0ccd:0036] 3 -> Pinnacle PCTV USB 2 (em2820/em2840) [2304:0208] 4 -> Hauppauge WinTV USB 2 (em2820/em2840) [2040:4200,2040:4201] @@ -12,9 +12,9 @@ 11 -> Terratec Hybrid XS (em2880) [0ccd:0042] 12 -> Kworld PVR TV 2800 RF (em2820/em2840) 13 -> Terratec Prodigy XS (em2880) [0ccd:0047] - 14 -> Pixelview Prolink PlayTV USB 2.0 (em2820/em2840) [eb1a:2821] + 14 -> Pixelview Prolink PlayTV USB 2.0 (em2820/em2840) 15 -> V-Gear PocketTV (em2800) - 16 -> Hauppauge WinTV HVR 950 (em2883) [2040:6513,2040:6517,2040:651b,2040:651f] + 16 -> Hauppauge WinTV HVR 950 (em2883) [2040:6513,2040:6517,2040:651b] 17 -> Pinnacle PCTV HD Pro Stick (em2880) [2304:0227] 18 -> Hauppauge WinTV HVR 900 (R2) (em2880) [2040:6502] 19 -> PointNix Intra-Oral Camera (em2860) @@ -27,7 +27,6 @@ 26 -> Hercules Smart TV USB 2.0 (em2820/em2840) 27 -> Pinnacle PCTV USB 2 (Philips FM1216ME) (em2820/em2840) 28 -> Leadtek Winfast USB II Deluxe (em2820/em2840) - 29 -> Pinnacle Dazzle DVC 100 (em2820/em2840) 30 -> Videology 20K14XUSB USB2.0 (em2820/em2840) 31 -> Usbgear VD204v9 (em2821) 32 -> Supercomp USB 2.0 TV (em2821) @@ -57,3 +56,5 @@ 56 -> Pinnacle Hybrid Pro (2) (em2882) [2304:0226] 57 -> Kworld PlusTV HD Hybrid 330 (em2883) [eb1a:a316] 58 -> Compro VideoMate ForYou/Stereo (em2820/em2840) [185b:2041] + 60 -> Hauppauge WinTV HVR 850 (em2883) [2040:651f] + 61 -> Pixelview PlayTV Box 4 USB 2.0 (em2820/em2840) diff --git a/Documentation/video4linux/CARDLIST.saa7134 b/Documentation/video4linux/CARDLIST.saa7134 index dc67eef38ff..335aef4dcae 100644 --- a/Documentation/video4linux/CARDLIST.saa7134 +++ b/Documentation/video4linux/CARDLIST.saa7134 @@ -10,7 +10,7 @@ 9 -> Medion 5044 10 -> Kworld/KuroutoShikou SAA7130-TVPCI 11 -> Terratec Cinergy 600 TV [153b:1143] - 12 -> Medion 7134 [16be:0003] + 12 -> Medion 7134 [16be:0003,16be:5000] 13 -> Typhoon TV+Radio 90031 14 -> ELSA EX-VISION 300TV [1048:226b] 15 -> ELSA EX-VISION 500TV [1048:226a] @@ -151,3 +151,4 @@ 150 -> Zogis Real Angel 220 151 -> ADS Tech Instant HDTV [1421:0380] 152 -> Asus Tiger Rev:1.00 [1043:4857] +153 -> Kworld Plus TV Analog Lite PCI [17de:7128] diff --git a/Documentation/video4linux/README.cx88 b/Documentation/video4linux/README.cx88 index 166d5960b1a..35fae23f883 100644 --- a/Documentation/video4linux/README.cx88 +++ b/Documentation/video4linux/README.cx88 @@ -1,4 +1,3 @@ - cx8800 release notes ==================== @@ -10,21 +9,20 @@ current status video - Basically works. - - Some minor image quality glitches. - - For now only capture, overlay support isn't completed yet. + - For now, only capture and read(). Overlay isn't supported. audio - The chip specs for the on-chip TV sound decoder are next to useless :-/ - Neverless the builtin TV sound decoder starts working now, - at least for PAL-BG. Other TV norms need other code ... + at least for some standards. FOR ANY REPORTS ON THIS PLEASE MENTION THE TV NORM YOU ARE USING. - Most tuner chips do provide mono sound, which may or may not be useable depending on the board design. With the Hauppauge cards it works, so there is mono sound available as fallback. - audio data dma (i.e. recording without loopback cable to the - sound card) should be possible, but there is no code yet ... + sound card) is supported via cx88-alsa. vbi - Code present. Works for NTSC closed caption. PAL and other diff --git a/Documentation/video4linux/gspca.txt b/Documentation/video4linux/gspca.txt index 004818fab04..1c58a763014 100644 --- a/Documentation/video4linux/gspca.txt +++ b/Documentation/video4linux/gspca.txt @@ -50,9 +50,14 @@ ov519 045e:028c Micro$oft xbox cam spca508 0461:0815 Micro Innovation IC200 sunplus 0461:0821 Fujifilm MV-1 zc3xx 0461:0a00 MicroInnovation WebCam320 +stv06xx 046d:0840 QuickCam Express +stv06xx 046d:0850 LEGO cam / QuickCam Web +stv06xx 046d:0870 Dexxa WebCam USB spca500 046d:0890 Logitech QuickCam traveler vc032x 046d:0892 Logitech Orbicam vc032x 046d:0896 Logitech Orbicam +vc032x 046d:0897 Logitech QuickCam for Dell notebooks +zc3xx 046d:089d Logitech QuickCam E2500 zc3xx 046d:08a0 Logitech QC IM zc3xx 046d:08a1 Logitech QC IM 0x08A1 +sound zc3xx 046d:08a2 Labtec Webcam Pro @@ -169,6 +174,9 @@ spca500 06bd:0404 Agfa CL20 spca500 06be:0800 Optimedia sunplus 06d6:0031 Trust 610 LCD PowerC@m Zoom spca506 06e1:a190 ADS Instant VCD +ov534 06f8:3002 Hercules Blog Webcam +ov534 06f8:3003 Hercules Dualpix HD Weblog +sonixj 06f8:3004 Hercules Classic Silver spca508 0733:0110 ViewQuest VQ110 spca508 0130:0130 Clone Digital Webcam 11043 spca501 0733:0401 Intel Create and Share @@ -199,7 +207,8 @@ sunplus 08ca:2050 Medion MD 41437 sunplus 08ca:2060 Aiptek PocketDV5300 tv8532 0923:010f ICM532 cams mars 093a:050f Mars-Semi Pc-Camera -pac207 093a:2460 PAC207 Qtec Webcam 100 +pac207 093a:2460 Qtec Webcam 100 +pac207 093a:2461 HP Webcam pac207 093a:2463 Philips SPC 220 NC pac207 093a:2464 Labtec Webcam 1200 pac207 093a:2468 PAC207 @@ -213,10 +222,13 @@ pac7311 093a:2603 PAC7312 pac7311 093a:2608 Trust WB-3300p pac7311 093a:260e Gigaware VGA PC Camera, Trust WB-3350p, SIGMA cam 2350 pac7311 093a:260f SnakeCam +pac7311 093a:2620 Apollo AC-905 pac7311 093a:2621 PAC731x +pac7311 093a:2622 Genius Eye 312 pac7311 093a:2624 PAC7302 pac7311 093a:2626 Labtec 2200 pac7311 093a:262a Webcam 300k +pac7311 093a:262c Philips SPC 230 NC zc3xx 0ac8:0302 Z-star Vimicro zc0302 vc032x 0ac8:0321 Vimicro generic vc0321 vc032x 0ac8:0323 Vimicro Vc0323 @@ -249,11 +261,13 @@ sonixj 0c45:60c0 Sangha Sn535 sonixj 0c45:60ec SN9C105+MO4000 sonixj 0c45:60fb Surfer NoName sonixj 0c45:60fc LG-LIC300 +sonixj 0c45:60fe Microdia Audio sonixj 0c45:6128 Microdia/Sonix SNP325 sonixj 0c45:612a Avant Camera sonixj 0c45:612c Typhoon Rasy Cam 1.3MPix sonixj 0c45:6130 Sonix Pccam sonixj 0c45:6138 Sn9c120 Mo4000 +sonixj 0c45:613a Microdia Sonix PC Camera sonixj 0c45:613b Surfer SN-206 sonixj 0c45:613c Sonix Pccam168 sonixj 0c45:6143 Sonix Pccam168 @@ -263,6 +277,9 @@ etoms 102c:6251 Qcam xxxxxx VGA zc3xx 10fd:0128 Typhoon Webshot II USB 300k 0x0128 spca561 10fd:7e50 FlyCam Usb 100 zc3xx 10fd:8050 Typhoon Webshot II USB 300k +ov534 1415:2000 Sony HD Eye for PS3 (SLEH 00201) +pac207 145f:013a Trust WB-1300N +vc032x 15b8:6002 HP 2.0 Megapixel rz406aa spca501 1776:501c Arowana 300K CMOS Camera t613 17a1:0128 TASCORP JPEG Webcam, NGS Cyclops vc032x 17ef:4802 Lenovo Vc0323+MI1310_SOC diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt new file mode 100644 index 00000000000..eeae76c22a9 --- /dev/null +++ b/Documentation/video4linux/v4l2-framework.txt @@ -0,0 +1,520 @@ +Overview of the V4L2 driver framework +===================================== + +This text documents the various structures provided by the V4L2 framework and +their relationships. + + +Introduction +------------ + +The V4L2 drivers tend to be very complex due to the complexity of the +hardware: most devices have multiple ICs, export multiple device nodes in +/dev, and create also non-V4L2 devices such as DVB, ALSA, FB, I2C and input +(IR) devices. + +Especially the fact that V4L2 drivers have to setup supporting ICs to +do audio/video muxing/encoding/decoding makes it more complex than most. +Usually these ICs are connected to the main bridge driver through one or +more I2C busses, but other busses can also be used. Such devices are +called 'sub-devices'. + +For a long time the framework was limited to the video_device struct for +creating V4L device nodes and video_buf for handling the video buffers +(note that this document does not discuss the video_buf framework). + +This meant that all drivers had to do the setup of device instances and +connecting to sub-devices themselves. Some of this is quite complicated +to do right and many drivers never did do it correctly. + +There is also a lot of common code that could never be refactored due to +the lack of a framework. + +So this framework sets up the basic building blocks that all drivers +need and this same framework should make it much easier to refactor +common code into utility functions shared by all drivers. + + +Structure of a driver +--------------------- + +All drivers have the following structure: + +1) A struct for each device instance containing the device state. + +2) A way of initializing and commanding sub-devices (if any). + +3) Creating V4L2 device nodes (/dev/videoX, /dev/vbiX, /dev/radioX and + /dev/vtxX) and keeping track of device-node specific data. + +4) Filehandle-specific structs containing per-filehandle data. + +This is a rough schematic of how it all relates: + + device instances + | + +-sub-device instances + | + \-V4L2 device nodes + | + \-filehandle instances + + +Structure of the framework +-------------------------- + +The framework closely resembles the driver structure: it has a v4l2_device +struct for the device instance data, a v4l2_subdev struct to refer to +sub-device instances, the video_device struct stores V4L2 device node data +and in the future a v4l2_fh struct will keep track of filehandle instances +(this is not yet implemented). + + +struct v4l2_device +------------------ + +Each device instance is represented by a struct v4l2_device (v4l2-device.h). +Very simple devices can just allocate this struct, but most of the time you +would embed this struct inside a larger struct. + +You must register the device instance: + + v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); + +Registration will initialize the v4l2_device struct and link dev->driver_data +to v4l2_dev. Registration will also set v4l2_dev->name to a value derived from +dev (driver name followed by the bus_id, to be precise). You may change the +name after registration if you want. + +The first 'dev' argument is normally the struct device pointer of a pci_dev, +usb_device or platform_device. + +You unregister with: + + v4l2_device_unregister(struct v4l2_device *v4l2_dev); + +Unregistering will also automatically unregister all subdevs from the device. + +Sometimes you need to iterate over all devices registered by a specific +driver. This is usually the case if multiple device drivers use the same +hardware. E.g. the ivtvfb driver is a framebuffer driver that uses the ivtv +hardware. The same is true for alsa drivers for example. + +You can iterate over all registered devices as follows: + +static int callback(struct device *dev, void *p) +{ + struct v4l2_device *v4l2_dev = dev_get_drvdata(dev); + + /* test if this device was inited */ + if (v4l2_dev == NULL) + return 0; + ... + return 0; +} + +int iterate(void *p) +{ + struct device_driver *drv; + int err; + + /* Find driver 'ivtv' on the PCI bus. + pci_bus_type is a global. For USB busses use usb_bus_type. */ + drv = driver_find("ivtv", &pci_bus_type); + /* iterate over all ivtv device instances */ + err = driver_for_each_device(drv, NULL, p, callback); + put_driver(drv); + return err; +} + +Sometimes you need to keep a running counter of the device instance. This is +commonly used to map a device instance to an index of a module option array. + +The recommended approach is as follows: + +static atomic_t drv_instance = ATOMIC_INIT(0); + +static int __devinit drv_probe(struct pci_dev *dev, + const struct pci_device_id *pci_id) +{ + ... + state->instance = atomic_inc_return(&drv_instance) - 1; +} + + +struct v4l2_subdev +------------------ + +Many drivers need to communicate with sub-devices. These devices can do all +sort of tasks, but most commonly they handle audio and/or video muxing, +encoding or decoding. For webcams common sub-devices are sensors and camera +controllers. + +Usually these are I2C devices, but not necessarily. In order to provide the +driver with a consistent interface to these sub-devices the v4l2_subdev struct +(v4l2-subdev.h) was created. + +Each sub-device driver must have a v4l2_subdev struct. This struct can be +stand-alone for simple sub-devices or it might be embedded in a larger struct +if more state information needs to be stored. Usually there is a low-level +device struct (e.g. i2c_client) that contains the device data as setup +by the kernel. It is recommended to store that pointer in the private +data of v4l2_subdev using v4l2_set_subdevdata(). That makes it easy to go +from a v4l2_subdev to the actual low-level bus-specific device data. + +You also need a way to go from the low-level struct to v4l2_subdev. For the +common i2c_client struct the i2c_set_clientdata() call is used to store a +v4l2_subdev pointer, for other busses you may have to use other methods. + +From the bridge driver perspective you load the sub-device module and somehow +obtain the v4l2_subdev pointer. For i2c devices this is easy: you call +i2c_get_clientdata(). For other busses something similar needs to be done. +Helper functions exists for sub-devices on an I2C bus that do most of this +tricky work for you. + +Each v4l2_subdev contains function pointers that sub-device drivers can +implement (or leave NULL if it is not applicable). Since sub-devices can do +so many different things and you do not want to end up with a huge ops struct +of which only a handful of ops are commonly implemented, the function pointers +are sorted according to category and each category has its own ops struct. + +The top-level ops struct contains pointers to the category ops structs, which +may be NULL if the subdev driver does not support anything from that category. + +It looks like this: + +struct v4l2_subdev_core_ops { + int (*g_chip_ident)(struct v4l2_subdev *sd, struct v4l2_chip_ident *chip); + int (*log_status)(struct v4l2_subdev *sd); + int (*init)(struct v4l2_subdev *sd, u32 val); + ... +}; + +struct v4l2_subdev_tuner_ops { + ... +}; + +struct v4l2_subdev_audio_ops { + ... +}; + +struct v4l2_subdev_video_ops { + ... +}; + +struct v4l2_subdev_ops { + const struct v4l2_subdev_core_ops *core; + const struct v4l2_subdev_tuner_ops *tuner; + const struct v4l2_subdev_audio_ops *audio; + const struct v4l2_subdev_video_ops *video; +}; + +The core ops are common to all subdevs, the other categories are implemented +depending on the sub-device. E.g. a video device is unlikely to support the +audio ops and vice versa. + +This setup limits the number of function pointers while still making it easy +to add new ops and categories. + +A sub-device driver initializes the v4l2_subdev struct using: + + v4l2_subdev_init(subdev, &ops); + +Afterwards you need to initialize subdev->name with a unique name and set the +module owner. This is done for you if you use the i2c helper functions. + +A device (bridge) driver needs to register the v4l2_subdev with the +v4l2_device: + + int err = v4l2_device_register_subdev(device, subdev); + +This can fail if the subdev module disappeared before it could be registered. +After this function was called successfully the subdev->dev field points to +the v4l2_device. + +You can unregister a sub-device using: + + v4l2_device_unregister_subdev(subdev); + +Afterwards the subdev module can be unloaded and subdev->dev == NULL. + +You can call an ops function either directly: + + err = subdev->ops->core->g_chip_ident(subdev, &chip); + +but it is better and easier to use this macro: + + err = v4l2_subdev_call(subdev, core, g_chip_ident, &chip); + +The macro will to the right NULL pointer checks and returns -ENODEV if subdev +is NULL, -ENOIOCTLCMD if either subdev->core or subdev->core->g_chip_ident is +NULL, or the actual result of the subdev->ops->core->g_chip_ident ops. + +It is also possible to call all or a subset of the sub-devices: + + v4l2_device_call_all(dev, 0, core, g_chip_ident, &chip); + +Any subdev that does not support this ops is skipped and error results are +ignored. If you want to check for errors use this: + + err = v4l2_device_call_until_err(dev, 0, core, g_chip_ident, &chip); + +Any error except -ENOIOCTLCMD will exit the loop with that error. If no +errors (except -ENOIOCTLCMD) occured, then 0 is returned. + +The second argument to both calls is a group ID. If 0, then all subdevs are +called. If non-zero, then only those whose group ID match that value will +be called. Before a bridge driver registers a subdev it can set subdev->grp_id +to whatever value it wants (it's 0 by default). This value is owned by the +bridge driver and the sub-device driver will never modify or use it. + +The group ID gives the bridge driver more control how callbacks are called. +For example, there may be multiple audio chips on a board, each capable of +changing the volume. But usually only one will actually be used when the +user want to change the volume. You can set the group ID for that subdev to +e.g. AUDIO_CONTROLLER and specify that as the group ID value when calling +v4l2_device_call_all(). That ensures that it will only go to the subdev +that needs it. + +The advantage of using v4l2_subdev is that it is a generic struct and does +not contain any knowledge about the underlying hardware. So a driver might +contain several subdevs that use an I2C bus, but also a subdev that is +controlled through GPIO pins. This distinction is only relevant when setting +up the device, but once the subdev is registered it is completely transparent. + + +I2C sub-device drivers +---------------------- + +Since these drivers are so common, special helper functions are available to +ease the use of these drivers (v4l2-common.h). + +The recommended method of adding v4l2_subdev support to an I2C driver is to +embed the v4l2_subdev struct into the state struct that is created for each +I2C device instance. Very simple devices have no state struct and in that case +you can just create a v4l2_subdev directly. + +A typical state struct would look like this (where 'chipname' is replaced by +the name of the chip): + +struct chipname_state { + struct v4l2_subdev sd; + ... /* additional state fields */ +}; + +Initialize the v4l2_subdev struct as follows: + + v4l2_i2c_subdev_init(&state->sd, client, subdev_ops); + +This function will fill in all the fields of v4l2_subdev and ensure that the +v4l2_subdev and i2c_client both point to one another. + +You should also add a helper inline function to go from a v4l2_subdev pointer +to a chipname_state struct: + +static inline struct chipname_state *to_state(struct v4l2_subdev *sd) +{ + return container_of(sd, struct chipname_state, sd); +} + +Use this to go from the v4l2_subdev struct to the i2c_client struct: + + struct i2c_client *client = v4l2_get_subdevdata(sd); + +And this to go from an i2c_client to a v4l2_subdev struct: + + struct v4l2_subdev *sd = i2c_get_clientdata(client); + +Finally you need to make a command function to make driver->command() +call the right subdev_ops functions: + +static int subdev_command(struct i2c_client *client, unsigned cmd, void *arg) +{ + return v4l2_subdev_command(i2c_get_clientdata(client), cmd, arg); +} + +If driver->command is never used then you can leave this out. Eventually the +driver->command usage should be removed from v4l. + +Make sure to call v4l2_device_unregister_subdev(sd) when the remove() callback +is called. This will unregister the sub-device from the bridge driver. It is +safe to call this even if the sub-device was never registered. + + +The bridge driver also has some helper functions it can use: + +struct v4l2_subdev *sd = v4l2_i2c_new_subdev(adapter, "module_foo", "chipid", 0x36); + +This loads the given module (can be NULL if no module needs to be loaded) and +calls i2c_new_device() with the given i2c_adapter and chip/address arguments. +If all goes well, then it registers the subdev with the v4l2_device. It gets +the v4l2_device by calling i2c_get_adapdata(adapter), so you should make sure +that adapdata is set to v4l2_device when you setup the i2c_adapter in your +driver. + +You can also use v4l2_i2c_new_probed_subdev() which is very similar to +v4l2_i2c_new_subdev(), except that it has an array of possible I2C addresses +that it should probe. Internally it calls i2c_new_probed_device(). + +Both functions return NULL if something went wrong. + + +struct video_device +------------------- + +The actual device nodes in the /dev directory are created using the +video_device struct (v4l2-dev.h). This struct can either be allocated +dynamically or embedded in a larger struct. + +To allocate it dynamically use: + + struct video_device *vdev = video_device_alloc(); + + if (vdev == NULL) + return -ENOMEM; + + vdev->release = video_device_release; + +If you embed it in a larger struct, then you must set the release() +callback to your own function: + + struct video_device *vdev = &my_vdev->vdev; + + vdev->release = my_vdev_release; + +The release callback must be set and it is called when the last user +of the video device exits. + +The default video_device_release() callback just calls kfree to free the +allocated memory. + +You should also set these fields: + +- parent: set to the parent device (same device as was used to register + v4l2_device). +- name: set to something descriptive and unique. +- fops: set to the file_operations struct. +- ioctl_ops: if you use the v4l2_ioctl_ops to simplify ioctl maintenance + (highly recommended to use this and it might become compulsory in the + future!), then set this to your v4l2_ioctl_ops struct. + +If you use v4l2_ioctl_ops, then you should set .unlocked_ioctl to +__video_ioctl2 or .ioctl to video_ioctl2 in your file_operations struct. + + +video_device registration +------------------------- + +Next you register the video device: this will create the character device +for you. + + err = video_register_device(vdev, VFL_TYPE_GRABBER, -1); + if (err) { + video_device_release(vdev); // or kfree(my_vdev); + return err; + } + +Which device is registered depends on the type argument. The following +types exist: + +VFL_TYPE_GRABBER: videoX for video input/output devices +VFL_TYPE_VBI: vbiX for vertical blank data (i.e. closed captions, teletext) +VFL_TYPE_RADIO: radioX for radio tuners +VFL_TYPE_VTX: vtxX for teletext devices (deprecated, don't use) + +The last argument gives you a certain amount of control over the device +kernel number used (i.e. the X in videoX). Normally you will pass -1 to +let the v4l2 framework pick the first free number. But if a driver creates +many devices, then it can be useful to have different video devices in +separate ranges. For example, video capture devices start at 0, video +output devices start at 16. + +So you can use the last argument to specify a minimum kernel number and +the v4l2 framework will try to pick the first free number that is equal +or higher to what you passed. If that fails, then it will just pick the +first free number. + +Whenever a device node is created some attributes are also created for you. +If you look in /sys/class/video4linux you see the devices. Go into e.g. +video0 and you will see 'name' and 'index' attributes. The 'name' attribute +is the 'name' field of the video_device struct. The 'index' attribute is +a device node index that can be assigned by the driver, or that is calculated +for you. + +If you call video_register_device(), then the index is just increased by +1 for each device node you register. The first video device node you register +always starts off with 0. + +Alternatively you can call video_register_device_index() which is identical +to video_register_device(), but with an extra index argument. Here you can +pass a specific index value (between 0 and 31) that should be used. + +Users can setup udev rules that utilize the index attribute to make fancy +device names (e.g. 'mpegX' for MPEG video capture device nodes). + +After the device was successfully registered, then you can use these fields: + +- vfl_type: the device type passed to video_register_device. +- minor: the assigned device minor number. +- num: the device kernel number (i.e. the X in videoX). +- index: the device index number (calculated or set explicitly using + video_register_device_index). + +If the registration failed, then you need to call video_device_release() +to free the allocated video_device struct, or free your own struct if the +video_device was embedded in it. The vdev->release() callback will never +be called if the registration failed, nor should you ever attempt to +unregister the device if the registration failed. + + +video_device cleanup +-------------------- + +When the video device nodes have to be removed, either during the unload +of the driver or because the USB device was disconnected, then you should +unregister them: + + video_unregister_device(vdev); + +This will remove the device nodes from sysfs (causing udev to remove them +from /dev). + +After video_unregister_device() returns no new opens can be done. + +However, in the case of USB devices some application might still have one +of these device nodes open. You should block all new accesses to read, +write, poll, etc. except possibly for certain ioctl operations like +queueing buffers. + +When the last user of the video device node exits, then the vdev->release() +callback is called and you can do the final cleanup there. + + +video_device helper functions +----------------------------- + +There are a few useful helper functions: + +You can set/get driver private data in the video_device struct using: + +void *video_get_drvdata(struct video_device *dev); +void video_set_drvdata(struct video_device *dev, void *data); + +Note that you can safely call video_set_drvdata() before calling +video_register_device(). + +And this function: + +struct video_device *video_devdata(struct file *file); + +returns the video_device belonging to the file struct. + +The final helper function combines video_get_drvdata with +video_devdata: + +void *video_drvdata(struct file *file); + +You can go from a video_device struct to the v4l2_device struct using: + +struct v4l2_device *v4l2_dev = dev_get_drvdata(vdev->parent); + |