2019-09-19 14:43:19 +00:00
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From d7aa9d52b7f9b2d600f9b2479767c24d438a2c68 Mon Sep 17 00:00:00 2001
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2019-07-09 18:32:28 +00:00
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From: Phil Elwell <phil@raspberrypi.org>
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Date: Tue, 3 Jul 2018 14:23:47 +0100
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2019-12-23 12:42:55 +00:00
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Subject: [PATCH] spi: Make GPIO CSs honour the SPI_NO_CS flag
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2019-07-09 18:32:28 +00:00
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The SPI configuration state includes an SPI_NO_CS flag that disables
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all CS line manipulation, for applications that want to manage their
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own chip selects. However, this flag is ignored by the GPIO CS code
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in the SPI framework.
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Correct this omission with a trivial patch.
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See: https://github.com/raspberrypi/linux/issues/2169
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Signed-off-by: Phil Elwell <phil@raspberrypi.org>
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---
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drivers/spi/spi.c | 4 +++-
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1 file changed, 3 insertions(+), 1 deletion(-)
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--- a/drivers/spi/spi.c
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+++ b/drivers/spi/spi.c
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@@ -733,7 +733,9 @@ static void spi_set_cs(struct spi_device
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enable = !enable;
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if (gpio_is_valid(spi->cs_gpio)) {
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- gpio_set_value_cansleep(spi->cs_gpio, !enable);
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+ /* Honour the SPI_NO_CS flag */
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+ if (!(spi->mode & SPI_NO_CS))
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+ gpio_set_value_cansleep(spi->cs_gpio, !enable);
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/* Some SPI masters need both GPIO CS & slave_select */
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if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
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spi->controller->set_cs)
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