[PATCH 1/8] ARM: SAMSUNG: Create a common infrastructure for PWM backlight support
Banajit Goswami
banajit.g at samsung.com
Fri Jul 15 10:42:41 EDT 2011
This patch creates a common structure for LCD backlight
using PWM timer to be used by various Samsung boards.
Signed-off-by: Banajit Goswami <banajit.g at samsung.com>
---
arch/arm/plat-samsung/Kconfig | 6 +
arch/arm/plat-samsung/Makefile | 1 +
arch/arm/plat-samsung/dev-backlight.c | 151 ++++++++++++++++++++++++
arch/arm/plat-samsung/include/plat/backlight.h | 26 ++++
4 files changed, 184 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/plat-samsung/dev-backlight.c
create mode 100644 arch/arm/plat-samsung/include/plat/backlight.h
diff --git a/arch/arm/plat-samsung/Kconfig b/arch/arm/plat-samsung/Kconfig
index 4d79519..b3e1065 100644
--- a/arch/arm/plat-samsung/Kconfig
+++ b/arch/arm/plat-samsung/Kconfig
@@ -280,6 +280,12 @@ config SAMSUNG_DEV_PWM
help
Compile in platform device definition for PWM Timer
+config SAMSUNG_DEV_BACKLIGHT
+ bool
+ depends on SAMSUNG_DEV_PWM
+ help
+ Compile in platform device definition LCD backlight with PWM Timer
+
config S3C24XX_PWM
bool "PWM device support"
select HAVE_PWM
diff --git a/arch/arm/plat-samsung/Makefile b/arch/arm/plat-samsung/Makefile
index 53eb15b..853764b 100644
--- a/arch/arm/plat-samsung/Makefile
+++ b/arch/arm/plat-samsung/Makefile
@@ -59,6 +59,7 @@ obj-$(CONFIG_SAMSUNG_DEV_IDE) += dev-ide.o
obj-$(CONFIG_SAMSUNG_DEV_TS) += dev-ts.o
obj-$(CONFIG_SAMSUNG_DEV_KEYPAD) += dev-keypad.o
obj-$(CONFIG_SAMSUNG_DEV_PWM) += dev-pwm.o
+obj-$(CONFIG_SAMSUNG_DEV_BACKLIGHT) += dev-backlight.o
# DMA support
diff --git a/arch/arm/plat-samsung/dev-backlight.c b/arch/arm/plat-samsung/dev-backlight.c
new file mode 100644
index 0000000..f960d1f
--- /dev/null
+++ b/arch/arm/plat-samsung/dev-backlight.c
@@ -0,0 +1,151 @@
+/* linux/arch/arm/plat-samsung/dev-backlight.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ * http://www.samsung.com
+ *
+ * Common infrastructure for PWM Backlight for Samsung boards
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/gpio.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/pwm_backlight.h>
+
+#include <plat/devs.h>
+#include <plat/gpio-cfg.h>
+#include <plat/backlight.h>
+
+static int samsung_bl_init(struct device *dev)
+{
+ int ret = 0;
+ struct platform_device *timer_dev =
+ container_of(dev->parent, struct platform_device, dev);
+ struct samsung_bl_gpio_info *bl_gpio_info =
+ timer_dev->dev.platform_data;
+
+ ret = gpio_request(bl_gpio_info->no, "Backlight");
+ if (ret) {
+ printk(KERN_ERR "failed to request GPIO for LCD Backlight\n");
+ return ret;
+ }
+
+ /* Configure GPIO pin with specific GPIO function for PWM timer */
+ s3c_gpio_cfgpin(bl_gpio_info->no, bl_gpio_info->func);
+
+ return 0;
+}
+
+static void samsung_bl_exit(struct device *dev)
+{
+ struct platform_device *timer_dev =
+ container_of(dev->parent, struct platform_device, dev);
+ struct samsung_bl_gpio_info *bl_gpio_info =
+ timer_dev->dev.platform_data;
+
+ s3c_gpio_cfgpin(bl_gpio_info->no, S3C_GPIO_OUTPUT);
+ gpio_free(bl_gpio_info->no);
+}
+
+/* Initialize few important fields of platform_pwm_backlight_data
+ * structure with default values. These fields can be overridden by
+ * board-specific values sent from machine file.
+ * For ease of operation, these fields are initialized with values
+ * used by most samsung boards.
+ * Users has the option of sending info about other parameters
+ * for their specific boards
+ */
+
+static struct platform_pwm_backlight_data samsung_dfl_bl_data __initdata = {
+ .max_brightness = 255,
+ .dft_brightness = 255,
+ .pwm_period_ns = 78770,
+ .init = samsung_bl_init,
+ .exit = samsung_bl_exit,
+};
+
+static struct platform_device samsung_dfl_bl_device __initdata = {
+ .name = "pwm-backlight",
+};
+
+/* samsung_bl_set - Set board specific data (if any) provided by user for
+ * PWM Backlight control and register specific PWM and backlight device.
+ * @gpio_info: structure containing GPIO info for PWM timer
+ * @bl_data: structure containing Backlight control data
+ */
+void samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
+ struct platform_pwm_backlight_data *bl_data)
+{
+ int ret = 0;
+ struct platform_device *samsung_bl_device;
+ struct platform_pwm_backlight_data *samsung_bl_data;
+
+ samsung_bl_device = kmemdup(&samsung_dfl_bl_device,
+ sizeof(struct platform_device), GFP_KERNEL);
+ if (!samsung_bl_device) {
+ printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
+ return;
+ }
+
+ samsung_bl_data = s3c_set_platdata(&samsung_dfl_bl_data,
+ sizeof(struct platform_pwm_backlight_data), samsung_bl_device);
+ if (!samsung_bl_data) {
+ printk(KERN_ERR "%s: no memory for platform dev\n", __func__);
+ goto err_data;
+ }
+
+ /* Copy board specific data provided by user */
+ samsung_bl_data->pwm_id = bl_data->pwm_id;
+ samsung_bl_device->dev.parent =
+ &s3c_device_timer[samsung_bl_data->pwm_id].dev;
+
+ if (bl_data->max_brightness)
+ samsung_bl_data->max_brightness = bl_data->max_brightness;
+ if (bl_data->dft_brightness)
+ samsung_bl_data->dft_brightness = bl_data->dft_brightness;
+ if (bl_data->lth_brightness)
+ samsung_bl_data->lth_brightness = bl_data->lth_brightness;
+ if (bl_data->pwm_period_ns)
+ samsung_bl_data->pwm_period_ns = bl_data->pwm_period_ns;
+ if (bl_data->init)
+ samsung_bl_data->init = bl_data->init;
+ if (bl_data->notify)
+ samsung_bl_data->notify = bl_data->notify;
+ if (bl_data->exit)
+ samsung_bl_data->exit = bl_data->exit;
+ if (bl_data->check_fb)
+ samsung_bl_data->check_fb = bl_data->check_fb;
+
+ /* Keep the GPIO info for future use */
+ s3c_device_timer[samsung_bl_data->pwm_id].dev.platform_data = gpio_info;
+
+ /* Register the specific PWM timer dev for Backlight control */
+ ret = platform_device_register(
+ &s3c_device_timer[samsung_bl_data->pwm_id]);
+ if (ret) {
+ printk(KERN_ERR "samsung: failed to register \
+ pwm timer for backlight: %d\n", ret);
+ goto err_plat_reg1;
+ }
+
+ /* Register the Backlight dev */
+ ret = platform_device_register(samsung_bl_device);
+ if (ret) {
+ printk(KERN_ERR "samsung: failed to register \
+ backlight device: %d\n", ret);
+ goto err_plat_reg2;
+ }
+
+ return;
+
+err_plat_reg2:
+ platform_device_unregister(&s3c_device_timer[samsung_bl_data->pwm_id]);
+err_plat_reg1:
+ kfree(samsung_bl_data);
+err_data:
+ kfree(samsung_bl_device);
+ return;
+}
diff --git a/arch/arm/plat-samsung/include/plat/backlight.h b/arch/arm/plat-samsung/include/plat/backlight.h
new file mode 100644
index 0000000..51d8da8
--- /dev/null
+++ b/arch/arm/plat-samsung/include/plat/backlight.h
@@ -0,0 +1,26 @@
+/* linux/arch/arm/plat-samsung/include/plat/backlight.h
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ * http://www.samsung.com
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_PLAT_BACKLIGHT_H
+#define __ASM_PLAT_BACKLIGHT_H __FILE__
+
+/* samsung_bl_gpio_info - GPIO info for PWM Backlight control
+ * @no: GPIO number for PWM timer out
+ * @func: Special function of GPIO line for PWM timer
+ */
+struct samsung_bl_gpio_info {
+ int no;
+ int func;
+};
+
+extern void samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
+ struct platform_pwm_backlight_data *bl_data);
+
+#endif /* __ASM_PLAT_BACKLIGHT_H */
--
1.7.2.3
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