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authorLars-Peter Clausen <lars@metafoo.de>2013-01-09 18:31:00 +0100
committerJonathan Cameron <jic23@kernel.org>2013-02-09 12:02:07 +0100
commit6d9eecd418afb2c12e5db5be3d72f0f1df43bdd9 (patch)
tree6c9fc5330e8e6970ab08f1c1220d612caeb44344 /drivers/iio/dac/ad5421.c
parentiio: mxs-lradc: Fix 'duplicate const' warning (diff)
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spi: Add helper functions for setting up transfers
Quite often the pattern used for setting up and transferring a synchronous SPI transaction looks very much like the following: struct spi_message msg; struct spi_transfer xfers[] = { ... }; spi_message_init(&msg); spi_message_add_tail(&xfers[0], &msg); ... spi_message_add_tail(&xfers[ARRAY_SIZE(xfers) - 1], &msg); ret = spi_sync(&msg); This patch adds two new helper functions for handling this case. The first helper function spi_message_init_with_transfers() takes a spi_message and an array of spi_transfers. It will initialize the message and then call spi_message_add_tail() for each transfer in the array. E.g. the following spi_message_init(&msg); spi_message_add_tail(&xfers[0], &msg); ... spi_message_add_tail(&xfers[ARRAY_SIZE(xfers) - 1], &msg); can be rewritten as spi_message_init_with_transfers(&msg, xfers, ARRAY_SIZE(xfers)); The second function spi_sync_transfer() takes a SPI device and an array of spi_transfers. It will allocate a new spi_message (on the stack) and add all transfers in the array to the message. Finally it will call spi_sync() on the message. E.g. the follwing struct spi_message msg; struct spi_transfer xfers[] = { ... }; spi_message_init(&msg); spi_message_add_tail(&xfers[0], &msg); ... spi_message_add_tail(&xfers[ARRAY_SIZE(xfers) - 1], &msg); ret = spi_sync(spi, &msg); can be rewritten as struct spi_transfer xfers[] = { ... }; ret = spi_sync_transfer(spi, xfers, ARRAY_SIZE(xfers)); A coccinelle script to find such instances will follow. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/iio/dac/ad5421.c')
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