linux-kernel - [PATCH 2/7] spi: atmel: Fix CS high support

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Date:   Thu, 17 Oct 2019 16:18:41 +0200
From:   Gregory CLEMENT <gregory.clement@...tlin.com>
To:     Mark Brown <broonie@...nel.org>, linux-spi@...r.kernel.org,
        linux-kernel@...r.kernel.org
Cc:     Nicolas Ferre <nicolas.ferre@...rochip.com>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Ludovic Desroches <ludovic.desroches@...rochip.com>,
        linux-arm-kernel@...ts.infradead.org,
        Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
        Gregory CLEMENT <gregory.clement@...tlin.com>,
        stable@...r.kernel.org
Subject: [PATCH 2/7] spi: atmel: Fix CS high support

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: 4820303480a1 ("spi: atmel: add support for the internal chip-select of the spi controller")
Cc: <stable@...r.kernel.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@...tlin.com>
---
 drivers/spi/spi-atmel.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 7a17c3e2a8ee..6e08ae539bc0 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -1176,10 +1176,8 @@ 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;
 	}

-- 
2.23.0