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path: root/drivers/spi/atmel_spi.c
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2007-07-17atmel_spi: don't always deselect chip between messagesDavid Brownell
Update chipselect handling for atmel_spi: * Teach it how to leave chipselect active between messages; this helps various drivers work better. * Cope with at91rm0200 errata: nCS0 can't be managed with GPIOs. The MR.PCS value is now updated whenever a chipselect changes. (This requires SPI pinmux init for that controller to change, and also testing on rm9200; doesn't break at91sam9 or avr32.) * Fix minor glitches: spi_setup() must leave chipselects inactive, as must removal of the spi_device. Also tweak diagnostic messaging to be a bit more useful. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17atmel_spi: minor updatesDavid Brownell
Minor updates to atmel_spi: - DMA: * Comments to explain the DMA policies * Report any mapping errors from spi_transfer() * Remove extra loop for DMA mapping - Diagnostics: report minimum clock rate, if we need to reject a spi_setup() request because that rate is too low. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17SPI controller drivers: check for unsupported modesDavid Brownell
Minor SPI controller driver updates: make the setup() methods reject spi->mode bits they don't support, by masking aginst the inverse of bits they *do* support. This insures against misbehavior later when new mode bits get added. Most controllers can't support SPI_LSB_FIRST; more handle SPI_CS_HIGH. Support for all four SPI clock/transfer modes is routine. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-01atmel_spi dma address bugfixHaavard Skinnemoen
When either rx_buf or tx_buf is not being used, i.e. for plain read- or write operations, the atmel_spi uses a fixed-size DMA buffer instead. If the transfer is longer than the size of this buffer, it is split into multiple DMA transfers. When the transfer is split like this, the atmel_spi driver ends up using the same DMA address again and again even for the buffer that came from the user, which is of course wrong. Fix this by adding the number of bytes already transferred to the DMA address so that the data ends up in the right place. Thanks to Wu Xuan for discovering this bug. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09atmel_spi: remove unnecessary (and wrong) #ifdefsHaavard Skinnemoen
Now that the cpu_is_xxx() macros are available both on AVR32 and AT91, we can remove a couple of #ifdefs from this driver. One of them is actually wrong -- new_1 should be set on AVR32 but isn't. This causes the bus clock to run at twice the speed it is configured to. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: David Brownell <david-b@pacbell.net> Acked-by: Andrew Victor <andrew@sanpeople.com> Cc: Nicolas Ferre <nicolas.ferre@rfo.atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-16[PATCH] gpio_direction_output() needs an initial valueDavid Brownell
It's been pointed out that output GPIOs should have an initial value, to avoid signal glitching ... among other things, it can be some time before a driver is ready. This patch corrects that oversight, fixing - documentation - platforms supporting the GPIO interface - users of that call (just one for now, others are pending) There's only one user of this call for now since most platforms are still using non-generic GPIO setup code, which in most cases already couples the initial value with its "set output mode" request. Note that most platforms are clear about the hardware letting the output value be set before the pin direction is changed, but the s3c241x docs are vague on that topic ... so those chips might not avoid the glitches. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Andrew Victor <andrew@sanpeople.com> Acked-by: Milan Svoboda <msvoboda@ra.rockwell.com> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-20[PATCH] SPI controller build/warning fixesDavid Brownell
The signature of the per-device cleanup() routine changed to remove its const-ness. Three new SPI controller drivers now need that change, to eliminate build warnings. This also fixes a build bug with atmel_spi on AT91 systems. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14[PATCH] SPI: atmel_spi driverHaavard Skinnemoen
Driver for the Atmel on-chip SPI master controller. Tested primarily on AVR32/AT32AP7000/ATSTK1000 using mtd_dataflash and the jffs2 filesystem. Should also work fine on various AT91 ARM-based chips like AT91SAM926x and AT91RM9200. Hardware documentation can be found in the AT32AP7000 data sheet, or its AT91 siblings, which can be downloaded from http://www.atmel.com/dyn/products/datasheets.asp?family_id=682 Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>