spi: imx/fsl-lpspi: Convert to GPIO descriptors

This converts the two Freescale i.MX SPI drivers
Freescale i.MX (CONFIG_SPI_IMX) and Freescale i.MX LPSPI
(CONFIG_SPI_FSL_LPSPI) to use GPIO descriptors handled in
the SPI core for GPIO chip selects whether defined in
the device tree or a board file.

The reason why both are converted at the same time is
that they were both using the same platform data and
platform device population helpers when using
board files intertwining the code so this gives a cleaner
cut.

The platform device creation was passing a platform data
container from each boardfile down to the driver using
struct spi_imx_master from <linux/platform_data/spi-imx.h>,
but this was only conveying the number of chipselects and
an int * array of the chipselect GPIO numbers.

The imx27 and imx31 platforms had code passing the
now-unused platform data when creating the platform devices,
this has been repurposed to pass around GPIO descriptor
tables. The platform data struct that was just passing an
array of integers and number of chip selects for the GPIO
lines has been removed.

The number of chipselects used to be passed from the board
file, because this number also limits the number of native
chipselects that the platform can use. To deal with this we
just augment the i.MX (CONFIG_SPI_IMX) driver to support 3
chipselects if the platform does not define "num-cs" as a
device property (such as from the device tree). This covers
all the legacy boards as these use <= 3 native chip selects
(or GPIO lines, and in that case the number of chip selects
is determined by the core from the number of available
GPIO lines). Any new boards should use device tree, so
this is a reasonable simplification to cover all old
boards.

The LPSPI driver never assigned the number of chipselects
and thus always fall back to the core default of 1 chip
select if no GPIOs are defined in the device tree.

The Freescale i.MX driver was already partly utilizing
the SPI core to obtain the GPIO numbers from the device tree,
so this completes the transtion to let the core handle all
of it.

All board files and the core i.MX boardfile registration
code is augmented to account for these changes.

This has been compile-tested with the imx_v4_v5_defconfig
and the imx_v6_v7_defconfig.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Robin Gong <yibin.gong@nxp.com>
Cc: Trent Piepho <tpiepho@impinj.com>
Cc: Clark Wang <xiaoning.wang@nxp.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Link: https://lore.kernel.org/r/20200625200252.207614-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 3 insertions, 44 deletions

diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c
index 1552b28b9515..38b44446c947 100644
--- a/drivers/spi/spi-fsl-lpspi.c
+++ b/drivers/spi/spi-fsl-lpspi.c
@@ -11,7 +11,6 @@
 #include <linux/dmaengine.h>
 #include <linux/dma-mapping.h>
 #include <linux/err.h>
-#include <linux/gpio.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/irq.h>
@@ -19,11 +18,9 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
-#include <linux/of_gpio.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/platform_data/dma-imx.h>
-#include <linux/platform_data/spi-imx.h>
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/spi/spi.h>
@@ -224,20 +221,6 @@ static int lpspi_unprepare_xfer_hardware(struct spi_controller *controller)
 	return 0;
 }
 
-static int fsl_lpspi_prepare_message(struct spi_controller *controller,
-				     struct spi_message *msg)
-{
-	struct fsl_lpspi_data *fsl_lpspi =
-					spi_controller_get_devdata(controller);
-	struct spi_device *spi = msg->spi;
-	int gpio = fsl_lpspi->chipselect[spi->chip_select];
-
-	if (gpio_is_valid(gpio))
-		gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
-
-	return 0;
-}
-
 static void fsl_lpspi_write_tx_fifo(struct fsl_lpspi_data *fsl_lpspi)
 {
 	u8 txfifo_cnt;
@@ -831,13 +814,10 @@ static int fsl_lpspi_init_rpm(struct fsl_lpspi_data *fsl_lpspi)
 
 static int fsl_lpspi_probe(struct platform_device *pdev)
 {
-	struct device_node *np = pdev->dev.of_node;
 	struct fsl_lpspi_data *fsl_lpspi;
 	struct spi_controller *controller;
-	struct spi_imx_master *lpspi_platform_info =
-		dev_get_platdata(&pdev->dev);
 	struct resource *res;
-	int i, ret, irq;
+	int ret, irq;
 	u32 temp;
 	bool is_slave;
 
@@ -867,6 +847,8 @@ static int fsl_lpspi_probe(struct platform_device *pdev)
 	controller->dev.of_node = pdev->dev.of_node;
 	controller->bus_num = pdev->id;
 	controller->slave_abort = fsl_lpspi_slave_abort;
+	if (!fsl_lpspi->is_slave)
+		controller->use_gpio_descriptors = true;
 
 	ret = devm_spi_register_controller(&pdev->dev, controller);
 	if (ret < 0) {
@@ -874,29 +856,6 @@ static int fsl_lpspi_probe(struct platform_device *pdev)
 		goto out_controller_put;
 	}
 
-	if (!fsl_lpspi->is_slave) {
-		for (i = 0; i < controller->num_chipselect; i++) {
-			int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
-
-			if (!gpio_is_valid(cs_gpio) && lpspi_platform_info)
-				cs_gpio = lpspi_platform_info->chipselect[i];
-
-			fsl_lpspi->chipselect[i] = cs_gpio;
-			if (!gpio_is_valid(cs_gpio))
-				continue;
-
-			ret = devm_gpio_request(&pdev->dev,
-						fsl_lpspi->chipselect[i],
-						DRIVER_NAME);
-			if (ret) {
-				dev_err(&pdev->dev, "can't get cs gpios\n");
-				goto out_controller_put;
-			}
-		}
-		controller->cs_gpios = fsl_lpspi->chipselect;
-		controller->prepare_message = fsl_lpspi_prepare_message;
-	}
-
 	init_completion(&fsl_lpspi->xfer_done);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);