release/5.2.30/spi-atmel-Fix-CS-high-support.patch

From 80df4b7c27a1b26d31ddb7987bb92ee2b5fdb1e0 Mon Sep 17 00:00:00 2001
From: Gregory CLEMENT <gregory.clement@bootlin.com>
Date: Thu, 17 Oct 2019 16:18:41 +0200
Subject: [PATCH] spi: atmel: Fix CS high support

commit 7cbb16b2122c09f2ae393a1542fed628505b9da6 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: 4820303480a1 ("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: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index f00b367523cd..6a4540ba65ba 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -1182,10 +1182,8 @@ 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;
 	}
 
-- 
2.7.4