backlight: l4f00242t03: Convert to GPIO descriptors

This converts the l4f00242t03 backlight driver to use GPIO
descriptors and switches the two Freescale i.MX boards over
to passing descriptors instead of global GPIO numbers.

We use the typical names "enable" and "reset" as found in
the device tree bindings for panel GPIOs.

This saves a lot of code in the driver and makes it possible
to get rid of the platform data header altogether.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: NDaniel Thompson <daniel.thompson@linaro.org>
Acked-by: NShawn Guo <shawnguo@kernel.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

arch/arm/mach-imx/mach-mx27_3ds.c

@@ -13,6 +13,7 @@
 
 #include <linux/platform_device.h>
 #include <linux/gpio.h>
+#include <linux/gpio/machine.h>
 #include <linux/irq.h>
 #include <linux/usb/otg.h>
 #include <linux/usb/ulpi.h>
@@ -20,8 +21,6 @@
 #include <linux/mfd/mc13783.h>
 #include <linux/spi/spi.h>
 #include <linux/regulator/machine.h>
-#include <linux/spi/l4f00242t03.h>
-
 
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
@@ -351,9 +350,19 @@ static const struct imx_fb_platform_data mx27_3ds_fb_data __initconst = {
 };
 
 /* LCD */
-static struct l4f00242t03_pdata mx27_3ds_lcd_pdata = {
-	.reset_gpio		= LCD_RESET,
-	.data_enable_gpio	= LCD_ENABLE,
+static struct gpiod_lookup_table mx27_3ds_lcd_gpiod_table = {
+	.dev_id = "spi0.0", /* Bus 0 chipselect 0 */
+	.table = {
+		/*
+		 * The i.MX27 has the i.MX21 GPIO controller, the GPIOs
+		 * numbered IMX_GPIO_NR(1, 3) and IMX_GPIO_NR(1, 31)
+		 * are in "bank 1" which is subtracted by one in the macro
+		 * so these are actually bank 0 on "imx21-gpio.0".
+		 */
+		GPIO_LOOKUP("imx21-gpio.0", 3, "reset", GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP("imx21-gpio.0", 31, "enable", GPIO_ACTIVE_HIGH),
+		{ },
+	},
 };
 
 static struct spi_board_info mx27_3ds_spi_devs[] __initdata = {
@@ -370,7 +379,6 @@ static struct spi_board_info mx27_3ds_spi_devs[] __initdata = {
 		.max_speed_hz	= 5000000,
 		.bus_num	= 0,
 		.chip_select	= 0, /* SS0 */
-		.platform_data	= &mx27_3ds_lcd_pdata,
 	},
 };
 
@@ -416,6 +424,7 @@ static void __init mx27pdk_late_init(void)
 	if (!otg_mode_host)
 		imx27_add_fsl_usb2_udc(&otg_device_pdata);
 
+	gpiod_add_lookup_table(&mx27_3ds_lcd_gpiod_table);
 	mx27_3ds_spi_devs[0].irq = gpio_to_irq(PMIC_INT);
 	spi_register_board_info(mx27_3ds_spi_devs,
 				ARRAY_SIZE(mx27_3ds_spi_devs));

arch/arm/mach-imx/mach-mx31_3ds.c

@@ -10,10 +10,10 @@
 #include <linux/clk.h>
 #include <linux/irq.h>
 #include <linux/gpio.h>
+#include <linux/gpio/machine.h>
 #include <linux/platform_device.h>
 #include <linux/mfd/mc13783.h>
 #include <linux/spi/spi.h>
-#include <linux/spi/l4f00242t03.h>
 #include <linux/regulator/machine.h>
 #include <linux/usb/otg.h>
 #include <linux/usb/ulpi.h>
@@ -160,9 +160,23 @@ static struct mx3fb_platform_data mx3fb_pdata __initdata = {
 };
 
 /* LCD */
-static struct l4f00242t03_pdata mx31_3ds_l4f00242t03_pdata = {
-	.reset_gpio		= IOMUX_TO_GPIO(MX31_PIN_LCS1),
-	.data_enable_gpio	= IOMUX_TO_GPIO(MX31_PIN_SER_RS),
+static struct gpiod_lookup_table mx31_3ds_lcd_gpiod_table = {
+	.dev_id = "spi0.2", /* Bus 0 chipselect 2 */
+	.table = {
+		/*
+		 * "reset" has IOMUX_TO_GPIO(IOMUX_PIN(88, 28)).
+		 * The macro only shifts 88 to bits 9..16 and then
+		 * mask it and shift it back. The GPIO number is 88.
+		 * 88 is 2*32+24
+		 */
+		GPIO_LOOKUP("imx31-gpio.2", 24, "reset", GPIO_ACTIVE_HIGH),
+		/*
+		 * Same reasoning as above for
+		 * IOMUX_TO_GPIO(IOMUX_PIN(89, 27), pin 89 is 2*32+25.
+		 */
+		GPIO_LOOKUP("imx31-gpio.2", 25, "enable", GPIO_ACTIVE_HIGH),
+		{ },
+	},
 };
 
 /*
@@ -387,7 +401,6 @@ static struct spi_board_info mx31_3ds_spi_devs[] __initdata = {
 		.max_speed_hz	= 5000000,
 		.bus_num	= 0,
 		.chip_select	= 2, /* SS2 */
-		.platform_data	= &mx31_3ds_l4f00242t03_pdata,
 	},
 };
 
@@ -566,6 +579,7 @@ static void __init mx31_3ds_init(void)
 
 static void __init mx31_3ds_late(void)
 {
+	gpiod_add_lookup_table(&mx31_3ds_lcd_gpiod_table);
 	mx31_3ds_spi_devs[0].irq = gpio_to_irq(IOMUX_TO_GPIO(MX31_PIN_GPIO1_3));
 	spi_register_board_info(mx31_3ds_spi_devs,
 				ARRAY_SIZE(mx31_3ds_spi_devs));

drivers/video/backlight/l4f00242t03.c

@@ -14,13 +14,11 @@
 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/module.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/lcd.h>
 #include <linux/slab.h>
 #include <linux/regulator/consumer.h>
-
 #include <linux/spi/spi.h>
-#include <linux/spi/l4f00242t03.h>
 
 struct l4f00242t03_priv {
 	struct spi_device	*spi;
@@ -28,16 +26,18 @@ struct l4f00242t03_priv {
 	int lcd_state;
 	struct regulator *io_reg;
 	struct regulator *core_reg;
+	struct gpio_desc *reset;
+	struct gpio_desc *enable;
 };
 
-static void l4f00242t03_reset(unsigned int gpio)
+static void l4f00242t03_reset(struct gpio_desc *gpiod)
 {
 	pr_debug("l4f00242t03_reset.\n");
-	gpio_set_value(gpio, 1);
+	gpiod_set_value(gpiod, 1);
 	mdelay(100);
-	gpio_set_value(gpio, 0);
+	gpiod_set_value(gpiod, 0);
 	mdelay(10);	/* tRES >= 100us */
-	gpio_set_value(gpio, 1);
+	gpiod_set_value(gpiod, 1);
 	mdelay(20);
 }
 
@@ -45,7 +45,6 @@ static void l4f00242t03_reset(unsigned int gpio)
 
 static void l4f00242t03_lcd_init(struct spi_device *spi)
 {
-	struct l4f00242t03_pdata *pdata = dev_get_platdata(&spi->dev);
 	struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
 	const u16 cmd[] = { 0x36, param(0), 0x3A, param(0x60) };
 	int ret;
@@ -76,21 +75,20 @@ static void l4f00242t03_lcd_init(struct spi_device *spi)
 		return;
 	}
 
-	l4f00242t03_reset(pdata->reset_gpio);
+	l4f00242t03_reset(priv->reset);
 
-	gpio_set_value(pdata->data_enable_gpio, 1);
+	gpiod_set_value(priv->enable, 1);
 	msleep(60);
 	spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16));
 }
 
 static void l4f00242t03_lcd_powerdown(struct spi_device *spi)
 {
-	struct l4f00242t03_pdata *pdata = dev_get_platdata(&spi->dev);
 	struct l4f00242t03_priv *priv = spi_get_drvdata(spi);
 
 	dev_dbg(&spi->dev, "Powering down LCD\n");
 
-	gpio_set_value(pdata->data_enable_gpio, 0);
+	gpiod_set_value(priv->enable, 0);
 
 	regulator_disable(priv->io_reg);
 	regulator_disable(priv->core_reg);
@@ -168,13 +166,6 @@ static struct lcd_ops l4f_ops = {
 static int l4f00242t03_probe(struct spi_device *spi)
 {
 	struct l4f00242t03_priv *priv;
-	struct l4f00242t03_pdata *pdata = dev_get_platdata(&spi->dev);
-	int ret;
-
-	if (pdata == NULL) {
-		dev_err(&spi->dev, "Uninitialized platform data.\n");
-		return -EINVAL;
-	}
 
 	priv = devm_kzalloc(&spi->dev, sizeof(struct l4f00242t03_priv),
 				GFP_KERNEL);
@@ -187,21 +178,21 @@ static int l4f00242t03_probe(struct spi_device *spi)
 
 	priv->spi = spi;
 
-	ret = devm_gpio_request_one(&spi->dev, pdata->reset_gpio,
-			GPIOF_OUT_INIT_HIGH, "lcd l4f00242t03 reset");
-	if (ret) {
+	priv->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(priv->reset)) {
 		dev_err(&spi->dev,
 			"Unable to get the lcd l4f00242t03 reset gpio.\n");
-		return ret;
+		return PTR_ERR(priv->reset);
 	}
+	gpiod_set_consumer_name(priv->reset, "lcd l4f00242t03 reset");
 
-	ret = devm_gpio_request_one(&spi->dev, pdata->data_enable_gpio,
-			GPIOF_OUT_INIT_LOW, "lcd l4f00242t03 data enable");
-	if (ret) {
+	priv->enable = devm_gpiod_get(&spi->dev, "enable", GPIOD_OUT_LOW);
+	if (IS_ERR(priv->enable)) {
 		dev_err(&spi->dev,
 			"Unable to get the lcd l4f00242t03 data en gpio.\n");
-		return ret;
+		return PTR_ERR(priv->enable);
 	}
+	gpiod_set_consumer_name(priv->enable, "lcd l4f00242t03 data enable");
 
 	priv->io_reg = devm_regulator_get(&spi->dev, "vdd");
 	if (IS_ERR(priv->io_reg)) {

include/linux/spi/l4f00242t03.h

-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * l4f00242t03.h -- Platform glue for Epson L4F00242T03 LCD
- *
- * Copyright (c) 2009 Alberto Panizzo <maramaopercheseimorto@gmail.com>
- * Based on Marek Vasut work in lms283gf05.h
-*/
-
-#ifndef _INCLUDE_LINUX_SPI_L4F00242T03_H_
-#define _INCLUDE_LINUX_SPI_L4F00242T03_H_
-
-struct l4f00242t03_pdata {
-	unsigned int	reset_gpio;
-	unsigned int	data_enable_gpio;
-};
-
-#endif /* _INCLUDE_LINUX_SPI_L4F00242T03_H_ */