From 980a01c9bfb090cb8a991e39e56ac379c30c61b8 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Wed, 28 Jun 2006 07:47:15 -0700 Subject: [PATCH] [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 Signed-off-by: Linus Torvalds --- drivers/spi/spi.c | 1 + include/linux/spi/spi.h | 6 +++++- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 1cea4a6799f..ed1cdf6ac8f 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 e928c0dcc29..c8bb68099eb 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 */ }; -- 2.20.1