Add hackish TWL4030 PWM0 Backlight Driver

diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 2746bbc..8819cab 100644 (file)
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -162,6 +162,13 @@ config BACKLIGHT_GPIO
        help
          If you have a GPIO controlled backlight, say Y to enable this driver.
 
+config BACKLIGHT_TWL4030_PWM0
+       tristate "TWL4030 PWM0 Backlight Driver"
+       depends on BACKLIGHT_CLASS_DEVICE && TWL4030_CORE
+       help
+         If you have a TWL4030 PWM0 controlled backlight, say Y to enable
+         this driver.
+
 config BACKLIGHT_MBP_NVIDIA
        tristate "MacBook Pro Nvidia Backlight Driver"
        depends on BACKLIGHT_CLASS_DEVICE && X86

diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index d122dbe..4145092 100644 (file)
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -16,5 +16,6 @@ obj-$(CONFIG_BACKLIGHT_PROGEAR) += progear_bl.o
 obj-$(CONFIG_BACKLIGHT_CARILLO_RANCH) += cr_bllcd.o
 obj-$(CONFIG_BACKLIGHT_PWM)    += pwm_bl.o
 obj-$(CONFIG_BACKLIGHT_GPIO)   += gpio_bl.o
+obj-$(CONFIG_BACKLIGHT_TWL4030_PWM0) += twl4030_pwm0_bl.o
 obj-$(CONFIG_BACKLIGHT_MBP_NVIDIA) += mbp_nvidia_bl.o
 

diff --git a/drivers/video/backlight/twl4030_pwm0_bl.c b/drivers/video/backlight/twl4030_pwm0_bl.c
new file mode 100644 (file)
index 0000000..2f15541
--- /dev/null
+++ b/drivers/video/backlight/twl4030_pwm0_bl.c
@@ -0,0 +1,160 @@
+/*
+ * Backlight driver for TWL4030 PWM0.
+ * Based on pwm_bl.c
+ *
+ * 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/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/fb.h>
+#include <linux/backlight.h>
+#include <linux/i2c/twl4030.h>
+#include <linux/err.h>
+
+#define TWL_PWM0_ON    0x00
+#define TWL_PWM0_OFF   0x01
+
+#define TWL_INTBR_GPBR1        0x0c
+#define TWL_INTBR_PMBR1        0x0d
+
+static int old_brightness;
+
+static int pwm0_backlight_update_status(struct backlight_device *bl)
+{
+       int brightness = bl->props.brightness;
+
+       if (bl->props.power != FB_BLANK_UNBLANK)
+               brightness = 0;
+
+       /* ignore fb blank for now
+       if (bl->props.fb_blank != FB_BLANK_UNBLANK)
+               brightness = 0;
+       */
+
+       if ((unsigned)brightness > 57)
+               brightness = 57;
+
+       if (brightness == 0) {
+               if (old_brightness != 0) {
+                       /* set OFF time to max,
+                        * then disable PWM0 output and clock */
+                       twl4030_i2c_write_u8(TWL4030_MODULE_PWM0, 0x3f,
+                                               TWL_PWM0_OFF);
+                       /* 0x49 0x91 */
+                       twl4030_i2c_write_u8(TWL4030_MODULE_INTBR, 0x01,
+                                               TWL_INTBR_GPBR1);
+                       twl4030_i2c_write_u8(TWL4030_MODULE_INTBR, 0x00,
+                                               TWL_INTBR_GPBR1);
+               }
+
+               goto done;
+       }
+
+       if (old_brightness == 0)
+               /* turn PWM0 output and clock on */
+               twl4030_i2c_write_u8(TWL4030_MODULE_INTBR, 0x05,
+                                       TWL_INTBR_GPBR1);
+
+       twl4030_i2c_write_u8(TWL4030_MODULE_PWM0, 6 + brightness,
+                               TWL_PWM0_OFF);
+
+done:
+       old_brightness = brightness;
+       return 0;
+}
+
+static int pwm0_backlight_get_brightness(struct backlight_device *bl)
+{
+       return bl->props.brightness;
+}
+
+static struct backlight_ops pwm0_backlight_ops = {
+       .update_status  = pwm0_backlight_update_status,
+       .get_brightness = pwm0_backlight_get_brightness,
+};
+
+static int pwm0_backlight_probe(struct platform_device *pdev)
+{
+       struct backlight_device *bl;
+
+       bl = backlight_device_register(pdev->name, &pdev->dev,
+                       NULL, &pwm0_backlight_ops);
+       if (IS_ERR(bl)) {
+               dev_err(&pdev->dev, "failed to register backlight\n");
+               return PTR_ERR(bl);
+       }
+
+       twl4030_i2c_write_u8(TWL4030_MODULE_PWM0, 0x81, TWL_PWM0_ON);
+
+       bl->props.max_brightness = 57;
+       bl->props.brightness = 57;
+       backlight_update_status(bl);
+
+       /* enable PWM function in pin mux (i2c addr 0x49 0x92) */
+       twl4030_i2c_write_u8(TWL4030_MODULE_INTBR, 0x04, TWL_INTBR_PMBR1);
+
+       return 0;
+}
+
+static int pwm0_backlight_remove(struct platform_device *pdev)
+{
+       struct backlight_device *bl = platform_get_drvdata(pdev);
+       backlight_device_unregister(bl);
+       return 0;
+}
+
+#ifdef CONFIG_PM
+static int pwm0_backlight_suspend(struct platform_device *pdev,
+                                pm_message_t state)
+{
+       /* turn PWM0 off */
+       twl4030_i2c_write_u8(TWL4030_MODULE_INTBR, 0x01, TWL_INTBR_GPBR1);
+       twl4030_i2c_write_u8(TWL4030_MODULE_INTBR, 0x00, TWL_INTBR_GPBR1);
+       old_brightness = 0;
+
+       return 0;
+}
+
+static int pwm0_backlight_resume(struct platform_device *pdev)
+{
+       struct backlight_device *bl = platform_get_drvdata(pdev);
+
+       backlight_update_status(bl);
+       return 0;
+}
+#else
+#define pwm0_backlight_suspend NULL
+#define pwm0_backlight_resume  NULL
+#endif
+
+static struct platform_driver pwm0_backlight_driver = {
+       .driver         = {
+               .name   = "twl4030-pwm0-bl",
+               .owner  = THIS_MODULE,
+       },
+       .probe          = pwm0_backlight_probe,
+       .remove         = pwm0_backlight_remove,
+       .suspend        = pwm0_backlight_suspend,
+       .resume         = pwm0_backlight_resume,
+};
+
+static int __init pwm0_backlight_init(void)
+{
+       return platform_driver_register(&pwm0_backlight_driver);
+}
+module_init(pwm0_backlight_init);
+
+static void __exit pwm0_backlight_exit(void)
+{
+       platform_driver_unregister(&pwm0_backlight_driver);
+}
+module_exit(pwm0_backlight_exit);
+
+MODULE_DESCRIPTION("TWL4030 PWM0 Backlight Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:twl4030-pwm0-bl");
+