Applied "spi: ath79: Convert to use CS GPIO descriptors" to the spi tree

[Mark Brown <broonie@xxxxxxxxxx>]

The patch

   spi: ath79: Convert to use CS GPIO descriptors

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 8db79547e79f6606b6d2d3b2bf6f36ec311195be Mon Sep 17 00:00:00 2001
From: Linus Walleij <linus.walleij@xxxxxxxxxx>
Date: Mon, 7 Jan 2019 16:51:51 +0100
Subject: [PATCH] spi: ath79: Convert to use CS GPIO descriptors

This converts the ATH79 SPI master driver to use GPIO descriptors
for chip select handling.

The ATH79 driver was requesting the GPIO and driving it from the
bitbang .chipselect callback. Do not request it anymore as the SPI
core will request it, remove the line inversion semantics for the
GPIO case (handled by gpiolib) and let the SPI core deal with
requesting the GPIO line from the device tree node of the controller.

This driver can be instantiated from a board file (no device tree)
but the board files only use native CS (no GPIO lines) so we should
be fine just letting the SPI core grab the GPIO from the device.

The fact that the driver is actively driving the GPIO in the
ath79_spi_chipselect() callback is confusing since the host does
not set SPI_MASTER_GPIO_SS so this should not ever get called when
using GPIO CS. I put in a comment about this.

Cc: Felix Fietkau <nbd@xxxxxxxx>
Cc: Alban Bedel <albeu@xxxxxxx>
Cc: Linuxarm <linuxarm@xxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
 drivers/spi/spi-ath79.c | 42 ++++++++++++++---------------------------
 1 file changed, 14 insertions(+), 28 deletions(-)

diff --git a/drivers/spi/spi-ath79.c b/drivers/spi/spi-ath79.c
index 3f6b657394de..ed1068ac055f 100644
--- a/drivers/spi/spi-ath79.c
+++ b/drivers/spi/spi-ath79.c
@@ -21,7 +21,7 @@
 #include <linux/spi/spi.h>
 #include <linux/spi/spi_bitbang.h>
 #include <linux/bitops.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/clk.h>
 #include <linux/err.h>
 
@@ -78,9 +78,16 @@ static void ath79_spi_chipselect(struct spi_device *spi, int is_active)
 		ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base);
 	}
 
-	if (gpio_is_valid(spi->cs_gpio)) {
-		/* SPI is normally active-low */
-		gpio_set_value_cansleep(spi->cs_gpio, cs_high);
+	if (spi->cs_gpiod) {
+		/*
+		 * SPI chipselect is normally active-low, but
+		 * inversion semantics are handled by gpiolib.
+		 *
+		 * FIXME: is this ever used? The driver doesn't
+		 * set SPI_MASTER_GPIO_SS so this callback should not
+		 * get called if a CS GPIO is found by the SPI core.
+		 */
+		gpiod_set_value_cansleep(spi->cs_gpiod, is_active);
 	} else {
 		u32 cs_bit = AR71XX_SPI_IOC_CS(spi->chip_select);
 
@@ -118,21 +125,8 @@ static void ath79_spi_disable(struct ath79_spi *sp)
 static int ath79_spi_setup_cs(struct spi_device *spi)
 {
 	struct ath79_spi *sp = ath79_spidev_to_sp(spi);
-	int status;
 
-	status = 0;
-	if (gpio_is_valid(spi->cs_gpio)) {
-		unsigned long flags;
-
-		flags = GPIOF_DIR_OUT;
-		if (spi->mode & SPI_CS_HIGH)
-			flags |= GPIOF_INIT_LOW;
-		else
-			flags |= GPIOF_INIT_HIGH;
-
-		status = gpio_request_one(spi->cs_gpio, flags,
-					  dev_name(&spi->dev));
-	} else {
+	if (!spi->cs_gpiod) {
 		u32 cs_bit = AR71XX_SPI_IOC_CS(spi->chip_select);
 
 		if (spi->mode & SPI_CS_HIGH)
@@ -143,13 +137,7 @@ static int ath79_spi_setup_cs(struct spi_device *spi)
 		ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base);
 	}
 
-	return status;
-}
-
-static void ath79_spi_cleanup_cs(struct spi_device *spi)
-{
-	if (gpio_is_valid(spi->cs_gpio))
-		gpio_free(spi->cs_gpio);
+	return 0;
 }
 
 static int ath79_spi_setup(struct spi_device *spi)
@@ -163,15 +151,12 @@ static int ath79_spi_setup(struct spi_device *spi)
 	}
 
 	status = spi_bitbang_setup(spi);
-	if (status && !spi->controller_state)
-		ath79_spi_cleanup_cs(spi);
 
 	return status;
 }
 
 static void ath79_spi_cleanup(struct spi_device *spi)
 {
-	ath79_spi_cleanup_cs(spi);
 	spi_bitbang_cleanup(spi);
 }
 
@@ -225,6 +210,7 @@ static int ath79_spi_probe(struct platform_device *pdev)
 
 	pdata = dev_get_platdata(&pdev->dev);
 
+	master->use_gpio_descriptors = true;
 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
 	master->setup = ath79_spi_setup;
 	master->cleanup = ath79_spi_cleanup;
-- 
2.20.1