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spi: atmel: Fix CS high support 

commit 7cbb16b212 upstream.

Until a few years ago, this driver was only used with CS GPIO. The
only exception is CS0 on AT91RM9200 which has to use internal CS. A
limitation of the internal CS is that they don't support CS High.

So by using the CS GPIO the CS high configuration was available except
for the particular case CS0 on RM9200.

When the support for the internal chip-select was added, the check of
the CS high support was not updated. Due to this the driver accepts
this configuration for all the SPI controller v2 (used by all SoCs
excepting the AT91RM9200) whereas the hardware doesn't support it for
infernal CS.

This patch fixes the test to match the hardware capabilities.

Fixes: 4820303480 ("spi: atmel: add support for the internal chip-select of the spi controller")
Cc: <stable@vger.kernel.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20191017141846.7523-3-gregory.clement@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5.4-rM2-2.2.x-imx-squashed
Gregory CLEMENT 2019-10-17 16:18:41 +02:00 committed by Greg Kroah-Hartman
parent 13978bd2d3
commit 0c6e9bb642
1 changed files with 2 additions and 4 deletions
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6
drivers/spi/spi-atmel.c
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@ -1183,10 +1183,8 @@ static int atmel_spi_setup(struct spi_device *spi)
as = spi_master_get_devdata(spi->master);
/* see notes above re chipselect */
if (!atmel_spi_is_v2(as)
&& spi->chip_select == 0
&& (spi->mode & SPI_CS_HIGH)) {
dev_dbg(&spi->dev, "setup: can't be active-high\n");
if (!as->use_cs_gpios && (spi->mode & SPI_CS_HIGH)) {
dev_warn(&spi->dev, "setup: non GPIO CS can't be active-high\n");
return -EINVAL;
}