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authorDavid Brownell <david-b@pacbell.net>2006-06-28 18:47:15 +0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-29 02:51:01 +0400
commit980a01c9bfb090cb8a991e39e56ac379c30c61b8 (patch)
tree8d14aa685d81abe410ce1842a6498878daf8a04d
parent8f7c58814eb75bf97b8bc18d107b2e26f28b6585 (diff)
downloadlinux-980a01c9bfb090cb8a991e39e56ac379c30c61b8.tar.xz
[PATCH] SPI: infrastructure to initialize spi_device.mode early
This patch adds earlier initialization of spi_device.mode, as needed on boards using nondefault chipselect polarity. An example would be ones using the RS5C348 RTC without an external signal inverter between the RTC chipselect and the SPI controller. Without this mechanism, the first setup() call for that chip would wrongly enable chips, corrupting transfers to/from other chips sharing that SPI bus. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--drivers/spi/spi.c1
-rw-r--r--include/linux/spi/spi.h6
2 files changed, 6 insertions, 1 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 1cea4a6799fe..ed1cdf6ac8f3 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -210,6 +210,7 @@ spi_new_device(struct spi_master *master, struct spi_board_info *chip)
proxy->master = master;
proxy->chip_select = chip->chip_select;
proxy->max_speed_hz = chip->max_speed_hz;
+ proxy->mode = chip->mode;
proxy->irq = chip->irq;
proxy->modalias = chip->modalias;
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index e928c0dcc297..c8bb68099eb9 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -642,10 +642,14 @@ struct spi_board_info {
u16 bus_num;
u16 chip_select;
+ /* mode becomes spi_device.mode, and is essential for chips
+ * where the default of SPI_CS_HIGH = 0 is wrong.
+ */
+ u8 mode;
+
/* ... may need additional spi_device chip config data here.
* avoid stuff protocol drivers can set; but include stuff
* needed to behave without being bound to a driver:
- * - chipselect polarity
* - quirks like clock rate mattering when not selected
*/
};