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authorIngo Molnar <mingo@elte.hu>2008-08-14 14:58:01 +0200
committerIngo Molnar <mingo@elte.hu>2008-08-14 14:58:01 +0200
commit51ca3c679194e7435c25b8e77b0a73c597e41ae9 (patch)
treea681dca369607ab0f371d5246b0f75140b860a8a /arch/powerpc/include/asm/smu.h
parentb55793f7528ce1b73c25b3ac8a86a6cda2a0f9a4 (diff)
parentb635acec48bcaa9183fcbf4e3955616b0d4119b5 (diff)
Merge branch 'linus' into x86/core
Conflicts: arch/x86/kernel/genapic_64.c include/asm-x86/kvm_host.h Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/powerpc/include/asm/smu.h')
-rw-r--r--arch/powerpc/include/asm/smu.h700
1 files changed, 700 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/smu.h b/arch/powerpc/include/asm/smu.h
new file mode 100644
index 00000000000..7ae2753da56
--- /dev/null
+++ b/arch/powerpc/include/asm/smu.h
@@ -0,0 +1,700 @@
+#ifndef _SMU_H
+#define _SMU_H
+
+/*
+ * Definitions for talking to the SMU chip in newer G5 PowerMacs
+ */
+#ifdef __KERNEL__
+#include <linux/list.h>
+#endif
+#include <linux/types.h>
+
+/*
+ * Known SMU commands
+ *
+ * Most of what is below comes from looking at the Open Firmware driver,
+ * though this is still incomplete and could use better documentation here
+ * or there...
+ */
+
+
+/*
+ * Partition info commands
+ *
+ * These commands are used to retrieve the sdb-partition-XX datas from
+ * the SMU. The length is always 2. First byte is the subcommand code
+ * and second byte is the partition ID.
+ *
+ * The reply is 6 bytes:
+ *
+ * - 0..1 : partition address
+ * - 2 : a byte containing the partition ID
+ * - 3 : length (maybe other bits are rest of header ?)
+ *
+ * The data must then be obtained with calls to another command:
+ * SMU_CMD_MISC_ee_GET_DATABLOCK_REC (described below).
+ */
+#define SMU_CMD_PARTITION_COMMAND 0x3e
+#define SMU_CMD_PARTITION_LATEST 0x01
+#define SMU_CMD_PARTITION_BASE 0x02
+#define SMU_CMD_PARTITION_UPDATE 0x03
+
+
+/*
+ * Fan control
+ *
+ * This is a "mux" for fan control commands. The command seem to
+ * act differently based on the number of arguments. With 1 byte
+ * of argument, this seem to be queries for fans status, setpoint,
+ * etc..., while with 0xe arguments, we will set the fans speeds.
+ *
+ * Queries (1 byte arg):
+ * ---------------------
+ *
+ * arg=0x01: read RPM fans status
+ * arg=0x02: read RPM fans setpoint
+ * arg=0x11: read PWM fans status
+ * arg=0x12: read PWM fans setpoint
+ *
+ * the "status" queries return the current speed while the "setpoint" ones
+ * return the programmed/target speed. It _seems_ that the result is a bit
+ * mask in the first byte of active/available fans, followed by 6 words (16
+ * bits) containing the requested speed.
+ *
+ * Setpoint (14 bytes arg):
+ * ------------------------
+ *
+ * first arg byte is 0 for RPM fans and 0x10 for PWM. Second arg byte is the
+ * mask of fans affected by the command. Followed by 6 words containing the
+ * setpoint value for selected fans in the mask (or 0 if mask value is 0)
+ */
+#define SMU_CMD_FAN_COMMAND 0x4a
+
+
+/*
+ * Battery access
+ *
+ * Same command number as the PMU, could it be same syntax ?
+ */
+#define SMU_CMD_BATTERY_COMMAND 0x6f
+#define SMU_CMD_GET_BATTERY_INFO 0x00
+
+/*
+ * Real time clock control
+ *
+ * This is a "mux", first data byte contains the "sub" command.
+ * The "RTC" part of the SMU controls the date, time, powerup
+ * timer, but also a PRAM
+ *
+ * Dates are in BCD format on 7 bytes:
+ * [sec] [min] [hour] [weekday] [month day] [month] [year]
+ * with month being 1 based and year minus 100
+ */
+#define SMU_CMD_RTC_COMMAND 0x8e
+#define SMU_CMD_RTC_SET_PWRUP_TIMER 0x00 /* i: 7 bytes date */
+#define SMU_CMD_RTC_GET_PWRUP_TIMER 0x01 /* o: 7 bytes date */
+#define SMU_CMD_RTC_STOP_PWRUP_TIMER 0x02
+#define SMU_CMD_RTC_SET_PRAM_BYTE_ACC 0x20 /* i: 1 byte (address?) */
+#define SMU_CMD_RTC_SET_PRAM_AUTOINC 0x21 /* i: 1 byte (data?) */
+#define SMU_CMD_RTC_SET_PRAM_LO_BYTES 0x22 /* i: 10 bytes */
+#define SMU_CMD_RTC_SET_PRAM_HI_BYTES 0x23 /* i: 10 bytes */
+#define SMU_CMD_RTC_GET_PRAM_BYTE 0x28 /* i: 1 bytes (address?) */
+#define SMU_CMD_RTC_GET_PRAM_LO_BYTES 0x29 /* o: 10 bytes */
+#define SMU_CMD_RTC_GET_PRAM_HI_BYTES 0x2a /* o: 10 bytes */
+#define SMU_CMD_RTC_SET_DATETIME 0x80 /* i: 7 bytes date */
+#define SMU_CMD_RTC_GET_DATETIME 0x81 /* o: 7 bytes date */
+
+ /*
+ * i2c commands
+ *
+ * To issue an i2c command, first is to send a parameter block to the
+ * the SMU. This is a command of type 0x9a with 9 bytes of header
+ * eventually followed by data for a write:
+ *
+ * 0: bus number (from device-tree usually, SMU has lots of busses !)
+ * 1: transfer type/format (see below)
+ * 2: device address. For combined and combined4 type transfers, this
+ * is the "write" version of the address (bit 0x01 cleared)
+ * 3: subaddress length (0..3)
+ * 4: subaddress byte 0 (or only byte for subaddress length 1)
+ * 5: subaddress byte 1
+ * 6: subaddress byte 2
+ * 7: combined address (device address for combined mode data phase)
+ * 8: data length
+ *
+ * The transfer types are the same good old Apple ones it seems,
+ * that is:
+ * - 0x00: Simple transfer
+ * - 0x01: Subaddress transfer (addr write + data tx, no restart)
+ * - 0x02: Combined transfer (addr write + restart + data tx)
+ *
+ * This is then followed by actual data for a write.
+ *
+ * At this point, the OF driver seems to have a limitation on transfer
+ * sizes of 0xd bytes on reads and 0x5 bytes on writes. I do not know
+ * wether this is just an OF limit due to some temporary buffer size
+ * or if this is an SMU imposed limit. This driver has the same limitation
+ * for now as I use a 0x10 bytes temporary buffer as well
+ *
+ * Once that is completed, a response is expected from the SMU. This is
+ * obtained via a command of type 0x9a with a length of 1 byte containing
+ * 0 as the data byte. OF also fills the rest of the data buffer with 0xff's
+ * though I can't tell yet if this is actually necessary. Once this command
+ * is complete, at this point, all I can tell is what OF does. OF tests
+ * byte 0 of the reply:
+ * - on read, 0xfe or 0xfc : bus is busy, wait (see below) or nak ?
+ * - on read, 0x00 or 0x01 : reply is in buffer (after the byte 0)
+ * - on write, < 0 -> failure (immediate exit)
+ * - else, OF just exists (without error, weird)
+ *
+ * So on read, there is this wait-for-busy thing when getting a 0xfc or
+ * 0xfe result. OF does a loop of up to 64 retries, waiting 20ms and
+ * doing the above again until either the retries expire or the result
+ * is no longer 0xfe or 0xfc
+ *
+ * The Darwin I2C driver is less subtle though. On any non-success status
+ * from the response command, it waits 5ms and tries again up to 20 times,
+ * it doesn't differenciate between fatal errors or "busy" status.
+ *
+ * This driver provides an asynchronous paramblock based i2c command
+ * interface to be used either directly by low level code or by a higher
+ * level driver interfacing to the linux i2c layer. The current
+ * implementation of this relies on working timers & timer interrupts
+ * though, so be careful of calling context for now. This may be "fixed"
+ * in the future by adding a polling facility.
+ */
+#define SMU_CMD_I2C_COMMAND 0x9a
+ /* transfer types */
+#define SMU_I2C_TRANSFER_SIMPLE 0x00
+#define SMU_I2C_TRANSFER_STDSUB 0x01
+#define SMU_I2C_TRANSFER_COMBINED 0x02
+
+/*
+ * Power supply control
+ *
+ * The "sub" command is an ASCII string in the data, the
+ * data length is that of the string.
+ *
+ * The VSLEW command can be used to get or set the voltage slewing.
+ * - length 5 (only "VSLEW") : it returns "DONE" and 3 bytes of
+ * reply at data offset 6, 7 and 8.
+ * - length 8 ("VSLEWxyz") has 3 additional bytes appended, and is
+ * used to set the voltage slewing point. The SMU replies with "DONE"
+ * I yet have to figure out their exact meaning of those 3 bytes in
+ * both cases. They seem to be:
+ * x = processor mask
+ * y = op. point index
+ * z = processor freq. step index
+ * I haven't yet decyphered result codes
+ *
+ */
+#define SMU_CMD_POWER_COMMAND 0xaa
+#define SMU_CMD_POWER_RESTART "RESTART"
+#define SMU_CMD_POWER_SHUTDOWN "SHUTDOWN"
+#define SMU_CMD_POWER_VOLTAGE_SLEW "VSLEW"
+
+/*
+ * Read ADC sensors
+ *
+ * This command takes one byte of parameter: the sensor ID (or "reg"
+ * value in the device-tree) and returns a 16 bits value
+ */
+#define SMU_CMD_READ_ADC 0xd8
+
+
+/* Misc commands
+ *
+ * This command seem to be a grab bag of various things
+ *
+ * Parameters:
+ * 1: subcommand
+ */
+#define SMU_CMD_MISC_df_COMMAND 0xdf
+
+/*
+ * Sets "system ready" status
+ *
+ * I did not yet understand how it exactly works or what it does.
+ *
+ * Guessing from OF code, 0x02 activates the display backlight. Apple uses/used
+ * the same codebase for all OF versions. On PowerBooks, this command would
+ * enable the backlight. For the G5s, it only activates the front LED. However,
+ * don't take this for granted.
+ *
+ * Parameters:
+ * 2: status [0x00, 0x01 or 0x02]
+ */
+#define SMU_CMD_MISC_df_SET_DISPLAY_LIT 0x02
+
+/*
+ * Sets mode of power switch.
+ *
+ * What this actually does is not yet known. Maybe it enables some interrupt.
+ *
+ * Parameters:
+ * 2: enable power switch? [0x00 or 0x01]
+ * 3 (optional): enable nmi? [0x00 or 0x01]
+ *
+ * Returns:
+ * If parameter 2 is 0x00 and parameter 3 is not specified, returns wether
+ * NMI is enabled. Otherwise unknown.
+ */
+#define SMU_CMD_MISC_df_NMI_OPTION 0x04
+
+/* Sets LED dimm offset.
+ *
+ * The front LED dimms itself during sleep. Its brightness (or, well, the PWM
+ * frequency) depends on current time. Therefore, the SMU needs to know the
+ * timezone.
+ *
+ * Parameters:
+ * 2-8: unknown (BCD coding)
+ */
+#define SMU_CMD_MISC_df_DIMM_OFFSET 0x99
+
+
+/*
+ * Version info commands
+ *
+ * Parameters:
+ * 1 (optional): Specifies version part to retrieve
+ *
+ * Returns:
+ * Version value
+ */
+#define SMU_CMD_VERSION_COMMAND 0xea
+#define SMU_VERSION_RUNNING 0x00
+#define SMU_VERSION_BASE 0x01
+#define SMU_VERSION_UPDATE 0x02
+
+
+/*
+ * Switches
+ *
+ * These are switches whose status seems to be known to the SMU.
+ *
+ * Parameters:
+ * none
+ *
+ * Result:
+ * Switch bits (ORed, see below)
+ */
+#define SMU_CMD_SWITCHES 0xdc
+
+/* Switches bits */
+#define SMU_SWITCH_CASE_CLOSED 0x01
+#define SMU_SWITCH_AC_POWER 0x04
+#define SMU_SWITCH_POWER_SWITCH 0x08
+
+
+/*
+ * Misc commands
+ *
+ * This command seem to be a grab bag of various things
+ *
+ * SMU_CMD_MISC_ee_GET_DATABLOCK_REC is used, among others, to
+ * transfer blocks of data from the SMU. So far, I've decrypted it's
+ * usage to retrieve partition data. In order to do that, you have to
+ * break your transfer in "chunks" since that command cannot transfer
+ * more than a chunk at a time. The chunk size used by OF is 0xe bytes,
+ * but it seems that the darwin driver will let you do 0x1e bytes if
+ * your "PMU" version is >= 0x30. You can get the "PMU" version apparently
+ * either in the last 16 bits of property "smu-version-pmu" or as the 16
+ * bytes at offset 1 of "smu-version-info"
+ *
+ * For each chunk, the command takes 7 bytes of arguments:
+ * byte 0: subcommand code (0x02)
+ * byte 1: 0x04 (always, I don't know what it means, maybe the address
+ * space to use or some other nicety. It's hard coded in OF)
+ * byte 2..5: SMU address of the chunk (big endian 32 bits)
+ * byte 6: size to transfer (up to max chunk size)
+ *
+ * The data is returned directly
+ */
+#define SMU_CMD_MISC_ee_COMMAND 0xee
+#define SMU_CMD_MISC_ee_GET_DATABLOCK_REC 0x02
+
+/* Retrieves currently used watts.
+ *
+ * Parameters:
+ * 1: 0x03 (Meaning unknown)
+ */
+#define SMU_CMD_MISC_ee_GET_WATTS 0x03
+
+#define SMU_CMD_MISC_ee_LEDS_CTRL 0x04 /* i: 00 (00,01) [00] */
+#define SMU_CMD_MISC_ee_GET_DATA 0x05 /* i: 00 , o: ?? */
+
+
+/*
+ * Power related commands
+ *
+ * Parameters:
+ * 1: subcommand
+ */
+#define SMU_CMD_POWER_EVENTS_COMMAND 0x8f
+
+/* SMU_POWER_EVENTS subcommands */
+enum {
+ SMU_PWR_GET_POWERUP_EVENTS = 0x00,
+ SMU_PWR_SET_POWERUP_EVENTS = 0x01,
+ SMU_PWR_CLR_POWERUP_EVENTS = 0x02,
+ SMU_PWR_GET_WAKEUP_EVENTS = 0x03,
+ SMU_PWR_SET_WAKEUP_EVENTS = 0x04,
+ SMU_PWR_CLR_WAKEUP_EVENTS = 0x05,
+
+ /*
+ * Get last shutdown cause
+ *
+ * Returns:
+ * 1 byte (signed char): Last shutdown cause. Exact meaning unknown.
+ */
+ SMU_PWR_LAST_SHUTDOWN_CAUSE = 0x07,
+
+ /*
+ * Sets or gets server ID. Meaning or use is unknown.
+ *
+ * Parameters:
+ * 2 (optional): Set server ID (1 byte)
+ *
+ * Returns:
+ * 1 byte (server ID?)
+ */
+ SMU_PWR_SERVER_ID = 0x08,
+};
+
+/* Power events wakeup bits */
+enum {
+ SMU_PWR_WAKEUP_KEY = 0x01, /* Wake on key press */
+ SMU_PWR_WAKEUP_AC_INSERT = 0x02, /* Wake on AC adapter plug */
+ SMU_PWR_WAKEUP_AC_CHANGE = 0x04,
+ SMU_PWR_WAKEUP_LID_OPEN = 0x08,
+ SMU_PWR_WAKEUP_RING = 0x10,
+};
+
+
+/*
+ * - Kernel side interface -
+ */
+
+#ifdef __KERNEL__
+
+/*
+ * Asynchronous SMU commands
+ *
+ * Fill up this structure and submit it via smu_queue_command(),
+ * and get notified by the optional done() callback, or because
+ * status becomes != 1
+ */
+
+struct smu_cmd;
+
+struct smu_cmd
+{
+ /* public */
+ u8 cmd; /* command */
+ int data_len; /* data len */
+ int reply_len; /* reply len */
+ void *data_buf; /* data buffer */
+ void *reply_buf; /* reply buffer */
+ int status; /* command status */
+ void (*done)(struct smu_cmd *cmd, void *misc);
+ void *misc;
+
+ /* private */
+ struct list_head link;
+};
+
+/*
+ * Queues an SMU command, all fields have to be initialized
+ */
+extern int smu_queue_cmd(struct smu_cmd *cmd);
+
+/*
+ * Simple command wrapper. This structure embeds a small buffer
+ * to ease sending simple SMU commands from the stack
+ */
+struct smu_simple_cmd
+{
+ struct smu_cmd cmd;
+ u8 buffer[16];
+};
+
+/*
+ * Queues a simple command. All fields will be initialized by that
+ * function
+ */
+extern int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
+ unsigned int data_len,
+ void (*done)(struct smu_cmd *cmd, void *misc),
+ void *misc,
+ ...);
+
+/*
+ * Completion helper. Pass it to smu_queue_simple or as 'done'
+ * member to smu_queue_cmd, it will call complete() on the struct
+ * completion passed in the "misc" argument
+ */
+extern void smu_done_complete(struct smu_cmd *cmd, void *misc);
+
+/*
+ * Synchronous helpers. Will spin-wait for completion of a command
+ */
+extern void smu_spinwait_cmd(struct smu_cmd *cmd);
+
+static inline void smu_spinwait_simple(struct smu_simple_cmd *scmd)
+{
+ smu_spinwait_cmd(&scmd->cmd);
+}
+
+/*
+ * Poll routine to call if blocked with irqs off
+ */
+extern void smu_poll(void);
+
+
+/*
+ * Init routine, presence check....
+ */
+extern int smu_init(void);
+extern int smu_present(void);
+struct of_device;
+extern struct of_device *smu_get_ofdev(void);
+
+
+/*
+ * Common command wrappers
+ */
+extern void smu_shutdown(void);
+extern void smu_restart(void);
+struct rtc_time;
+extern int smu_get_rtc_time(struct rtc_time *time, int spinwait);
+extern int smu_set_rtc_time(struct rtc_time *time, int spinwait);
+
+/*
+ * SMU command buffer absolute address, exported by pmac_setup,
+ * this is allocated very early during boot.
+ */
+extern unsigned long smu_cmdbuf_abs;
+
+
+/*
+ * Kenrel asynchronous i2c interface
+ */
+
+#define SMU_I2C_READ_MAX 0x1d
+#define SMU_I2C_WRITE_MAX 0x15
+
+/* SMU i2c header, exactly matches i2c header on wire */
+struct smu_i2c_param
+{
+ u8 bus; /* SMU bus ID (from device tree) */
+ u8 type; /* i2c transfer type */
+ u8 devaddr; /* device address (includes direction) */
+ u8 sublen; /* subaddress length */
+ u8 subaddr[3]; /* subaddress */
+ u8 caddr; /* combined address, filled by SMU driver */
+ u8 datalen; /* length of transfer */
+ u8 data[SMU_I2C_READ_MAX]; /* data */
+};
+
+struct smu_i2c_cmd
+{
+ /* public */
+ struct smu_i2c_param info;
+ void (*done)(struct smu_i2c_cmd *cmd, void *misc);
+ void *misc;
+ int status; /* 1 = pending, 0 = ok, <0 = fail */
+
+ /* private */
+ struct smu_cmd scmd;
+ int read;
+ int stage;
+ int retries;
+ u8 pdata[32];
+ struct list_head link;
+};
+
+/*
+ * Call this to queue an i2c command to the SMU. You must fill info,
+ * including info.data for a write, done and misc.
+ * For now, no polling interface is provided so you have to use completion
+ * callback.
+ */
+extern int smu_queue_i2c(struct smu_i2c_cmd *cmd);
+
+
+#endif /* __KERNEL__ */
+
+
+/*
+ * - SMU "sdb" partitions informations -
+ */
+
+
+/*
+ * Partition header format
+ */
+struct smu_sdbp_header {
+ __u8 id;
+ __u8 len;
+ __u8 version;
+ __u8 flags;
+};
+
+
+ /*
+ * demangle 16 and 32 bits integer in some SMU partitions
+ * (currently, afaik, this concerns only the FVT partition
+ * (0x12)
+ */
+#define SMU_U16_MIX(x) le16_to_cpu(x);
+#define SMU_U32_MIX(x) ((((x) & 0xff00ff00u) >> 8)|(((x) & 0x00ff00ffu) << 8))
+
+
+/* This is the definition of the SMU sdb-partition-0x12 table (called
+ * CPU F/V/T operating points in Darwin). The definition for all those
+ * SMU tables should be moved to some separate file
+ */
+#define SMU_SDB_FVT_ID 0x12
+
+struct smu_sdbp_fvt {
+ __u32 sysclk; /* Base SysClk frequency in Hz for
+ * this operating point. Value need to
+ * be unmixed with SMU_U32_MIX()
+ */
+ __u8 pad;
+ __u8 maxtemp; /* Max temp. supported by this
+ * operating point
+ */
+
+ __u16 volts[3]; /* CPU core voltage for the 3
+ * PowerTune modes, a mode with
+ * 0V = not supported. Value need
+ * to be unmixed with SMU_U16_MIX()
+ */
+};
+
+/* This partition contains voltage & current sensor calibration
+ * informations
+ */
+#define SMU_SDB_CPUVCP_ID 0x21
+
+struct smu_sdbp_cpuvcp {
+ __u16 volt_scale; /* u4.12 fixed point */
+ __s16 volt_offset; /* s4.12 fixed point */
+ __u16 curr_scale; /* u4.12 fixed point */
+ __s16 curr_offset; /* s4.12 fixed point */
+ __s32 power_quads[3]; /* s4.28 fixed point */
+};
+
+/* This partition contains CPU thermal diode calibration
+ */
+#define SMU_SDB_CPUDIODE_ID 0x18
+
+struct smu_sdbp_cpudiode {
+ __u16 m_value; /* u1.15 fixed point */
+ __s16 b_value; /* s10.6 fixed point */
+
+};
+
+/* This partition contains Slots power calibration
+ */
+#define SMU_SDB_SLOTSPOW_ID 0x78
+
+struct smu_sdbp_slotspow {
+ __u16 pow_scale; /* u4.12 fixed point */
+ __s16 pow_offset; /* s4.12 fixed point */
+};
+
+/* This partition contains machine specific version information about
+ * the sensor/control layout
+ */
+#define SMU_SDB_SENSORTREE_ID 0x25
+
+struct smu_sdbp_sensortree {
+ __u8 model_id;
+ __u8 unknown[3];
+};
+
+/* This partition contains CPU thermal control PID informations. So far
+ * only single CPU machines have been seen with an SMU, so we assume this
+ * carries only informations for those
+ */
+#define SMU_SDB_CPUPIDDATA_ID 0x17
+
+struct smu_sdbp_cpupiddata {
+ __u8 unknown1;
+ __u8 target_temp_delta;
+ __u8 unknown2;
+ __u8 history_len;
+ __s16 power_adj;
+ __u16 max_power;
+ __s32 gp,gr,gd;
+};
+
+
+/* Other partitions without known structures */
+#define SMU_SDB_DEBUG_SWITCHES_ID 0x05
+
+#ifdef __KERNEL__
+/*
+ * This returns the pointer to an SMU "sdb" partition data or NULL
+ * if not found. The data format is described below
+ */
+extern const struct smu_sdbp_header *smu_get_sdb_partition(int id,
+ unsigned int *size);
+
+/* Get "sdb" partition data from an SMU satellite */
+extern struct smu_sdbp_header *smu_sat_get_sdb_partition(unsigned int sat_id,
+ int id, unsigned int *size);
+
+
+#endif /* __KERNEL__ */
+
+
+/*
+ * - Userland interface -
+ */
+
+/*
+ * A given instance of the device can be configured for 2 different
+ * things at the moment:
+ *
+ * - sending SMU commands (default at open() time)
+ * - receiving SMU events (not yet implemented)
+ *
+ * Commands are written with write() of a command block. They can be
+ * "driver" commands (for example to switch to event reception mode)
+ * or real SMU commands. They are made of a header followed by command
+ * data if any.
+ *
+ * For SMU commands (not for driver commands), you can then read() back
+ * a reply. The reader will be blocked or not depending on how the device
+ * file is opened. poll() isn't implemented yet. The reply will consist
+ * of a header as well, followed by the reply data if any. You should
+ * always provide a buffer large enough for the maximum reply data, I
+ * recommand one page.
+ *
+ * It is illegal to send SMU commands through a file descriptor configured
+ * for events reception
+ *
+ */
+struct smu_user_cmd_hdr
+{
+ __u32 cmdtype;
+#define SMU_CMDTYPE_SMU 0 /* SMU command */
+#define SMU_CMDTYPE_WANTS_EVENTS 1 /* switch fd to events mode */
+#define SMU_CMDTYPE_GET_PARTITION 2 /* retrieve an sdb partition */
+
+ __u8 cmd; /* SMU command byte */
+ __u8 pad[3]; /* padding */
+ __u32 data_len; /* Length of data following */
+};
+
+struct smu_user_reply_hdr
+{
+ __u32 status; /* Command status */
+ __u32 reply_len; /* Length of data follwing */
+};
+
+#endif /* _SMU_H */