new file mode 100644
@@ -0,0 +1,15 @@
+gpio-lcd bindings
+
+Required properties:
+ - compatible: "gpio-lcd"
+ - gpios: describes the gpio that is used for enabling/disabling the lcd
+ (see GPIO binding[0] for more details).
+
+[0]: Documentation/devicetree/bindings/gpio/gpio.txt
+
+Example:
+
+ lcd {
+ compatible = "gpio-lcd";
+ gpios = <&gpio3 13 0>;
+ };
@@ -34,6 +34,14 @@ config LCD_CORGI
Say y here to support the LCD panels usually found on SHARP
corgi (C7x0) and spitz (Cxx00) models.
+config LCD_GPIO
+ tristate "LCD GPIO Driver"
+ depends on OF && GPIOLIB
+ help
+ If your LCD enbling/disabling is controlled by a GPIO
+ and that you use the device tree for booting,
+ say y to enable the LCD GPIO driver.
+
config LCD_L4F00242T03
tristate "Epson L4F00242T03 LCD"
depends on SPI_MASTER && GPIOLIB
@@ -3,6 +3,7 @@
obj-$(CONFIG_LCD_AMS369FG06) += ams369fg06.o
obj-$(CONFIG_LCD_CLASS_DEVICE) += lcd.o
obj-$(CONFIG_LCD_CORGI) += corgi_lcd.o
+obj-$(CONFIG_LCD_GPIO) += gpio_lcd.o
obj-$(CONFIG_LCD_HP700) += jornada720_lcd.o
obj-$(CONFIG_LCD_HX8357) += hx8357.o
obj-$(CONFIG_LCD_ILI922X) += ili922x.o
new file mode 100644
@@ -0,0 +1,178 @@
+/*
+ * drivers/video/backlight/gpio_lcd.c
+ *
+ * simple GPIO based lcd control.
+ *
+ * Copyright 2013 Eukréa Electromatique <denis@eukrea.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Based on drivers/video/backlight/platform_lcd.c
+ */
+
+#include <linux/lcd.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+
+struct gpio_lcd {
+ unsigned gpio;
+ u32 active_low; /* 1 if active_low, 0 otherwise */
+ struct lcd_device *lcd;
+ unsigned int power;
+ unsigned int suspended;
+};
+
+static int gpio_lcd_get_power(struct lcd_device *lcd)
+{
+ struct gpio_lcd *glcd = lcd_get_data(lcd);
+
+ return glcd->power;
+}
+
+static int gpio_lcd_set_power(struct lcd_device *lcd, int power)
+{
+ struct gpio_lcd *glcd = lcd_get_data(lcd);
+ int lcd_power = 1;
+ unsigned ret = 0;
+
+ if (power == FB_BLANK_POWERDOWN || glcd->suspended)
+ lcd_power = 0;
+
+ ret = gpio_direction_output(glcd->gpio,
+ lcd_power ? !glcd->active_low : glcd->active_low);
+
+ glcd->power = power;
+
+ return ret;
+}
+
+static struct lcd_ops gpio_lcd_ops = {
+ .get_power = gpio_lcd_get_power,
+ .set_power = gpio_lcd_set_power,
+};
+
+static int gpio_lcd_probe(struct platform_device *pdev)
+{
+ struct gpio_lcd *glcd;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = pdev->dev.of_node;
+ enum of_gpio_flags gpio_flags;
+ int ret = 0;
+
+ dev_info(&pdev->dev, "Initializing.\n");
+
+ glcd = devm_kzalloc(&pdev->dev, sizeof(*glcd), GFP_KERNEL);
+ if (!glcd) {
+ dev_err(&pdev->dev, "No memory for gpio_lcd.\n");
+ return -ENOMEM;
+ };
+
+ glcd->gpio = of_get_gpio_flags(np, 0, &gpio_flags);
+ glcd->active_low = gpio_flags & OF_GPIO_ACTIVE_LOW;
+ if (glcd->gpio == -EPROBE_DEFER) {
+ ret = ERR_PTR(-EPROBE_DEFER);
+ goto err_free_pdata;
+ } else if (glcd->gpio < 0) {
+ ret = glcd->gpio;
+ dev_err(&pdev->dev, "Error: gpios is a required parameter.\n");
+ goto err_free_pdata;
+ }
+
+ /* Request the LCD gpio */
+ ret = gpio_request(glcd->gpio, "LCDRST");
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failled to request LCD reset"
+ " GPIO %u.\n", glcd->gpio);
+ goto err_free_pdata;
+ }
+
+ glcd->lcd = lcd_device_register(dev_name(dev), dev,
+ glcd, &gpio_lcd_ops);
+ if (IS_ERR(glcd->lcd)) {
+ dev_err(dev, "Cannot register lcd device.\n");
+ ret = PTR_ERR(glcd->lcd);
+ goto err_free_pdata;
+ }
+
+ platform_set_drvdata(pdev, glcd);
+ gpio_lcd_set_power(glcd->lcd, FB_BLANK_NORMAL);
+
+ dev_info(&pdev->dev, "The LCD was Enabled by the GPIO %u which is %s.\n",
+ glcd->gpio,
+ glcd->active_low ? "active low" : "active high");
+
+ dev_info(&pdev->dev, "Initialized.\n");
+
+ return 0;
+
+err_free_pdata:
+ devm_kfree(&pdev->dev, glcd);
+ return ret;
+}
+
+static int gpio_lcd_remove(struct platform_device *pdev)
+{
+ struct gpio_lcd *glcd = platform_get_drvdata(pdev);
+
+ lcd_device_unregister(glcd->lcd);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int gpio_lcd_suspend(struct device *dev)
+{
+ struct gpio_lcd *glcd = dev_get_drvdata(dev);
+
+ glcd->suspended = 1;
+ return gpio_lcd_set_power(glcd->lcd, glcd->power);
+}
+
+static int gpio_lcd_resume(struct device *dev)
+{
+ struct gpio_lcd *glcd = dev_get_drvdata(dev);
+
+ glcd->suspended = 0;
+ return gpio_lcd_set_power(glcd->lcd, glcd->power);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(gpio_lcd_pm_ops, gpio_lcd_suspend,
+ gpio_lcd_resume);
+
+static struct of_device_id gpio_lcd_of_match[] = {
+ { .compatible = "gpio-lcd" },
+ { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, gpio_lcd_of_match);
+
+static struct platform_driver gpio_lcd_driver = {
+ .driver = {
+ .name = "gpio-lcd",
+ .owner = THIS_MODULE,
+ .pm = &gpio_lcd_pm_ops,
+ .of_match_table = of_match_ptr(gpio_lcd_of_match),
+ },
+ .probe = gpio_lcd_probe,
+ .remove = gpio_lcd_remove,
+};
+
+module_platform_driver(gpio_lcd_driver);
+
+MODULE_DESCRIPTION("GPIO based LCD Driver");
+MODULE_LICENSE("GPLv2");
+MODULE_ALIAS("platform:gpio-lcd");
Signed-off-by: Denis Carikli <denis@eukrea.com> --- .../bindings/video/backlight/gpio-lcd.txt | 15 ++ drivers/video/backlight/Kconfig | 8 + drivers/video/backlight/Makefile | 1 + drivers/video/backlight/gpio_lcd.c | 178 ++++++++++++++++++++ 4 files changed, 202 insertions(+) create mode 100644 Documentation/devicetree/bindings/video/backlight/gpio-lcd.txt create mode 100644 drivers/video/backlight/gpio_lcd.c