backlight: da903x: Add backlight driver for DA9030/DA9034

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

drivers/video/backlight/Kconfig

@@ -180,6 +180,13 @@ config BACKLIGHT_PWM
 	  If you have a LCD backlight adjustable by PWM, say Y to enable
 	  this driver.
 
+config BACKLIGHT_DA903X
+	tristate "Backlight Driver for DA9030/DA9034 using WLED"
+	depends on BACKLIGHT_CLASS_DEVICE && PMIC_DA903X
+	help
+	  If you have a LCD backlight connected to the WLED output of DA9030
+	  or DA9034 WLED output, say Y here to enable this driver.
+
 config BACKLIGHT_MBP_NVIDIA
        tristate "MacBook Pro Nvidia Backlight Driver"
        depends on BACKLIGHT_CLASS_DEVICE && X86

drivers/video/backlight/Makefile

@@ -18,6 +18,7 @@ obj-$(CONFIG_BACKLIGHT_OMAP1)	+= omap1_bl.o
 obj-$(CONFIG_BACKLIGHT_PROGEAR) += progear_bl.o
 obj-$(CONFIG_BACKLIGHT_CARILLO_RANCH) += cr_bllcd.o
 obj-$(CONFIG_BACKLIGHT_PWM)	+= pwm_bl.o
+obj-$(CONFIG_BACKLIGHT_DA903X)	+= da903x.o
 obj-$(CONFIG_BACKLIGHT_MBP_NVIDIA) += mbp_nvidia_bl.o
 obj-$(CONFIG_BACKLIGHT_TOSA)	+= tosa_bl.o
 

drivers/video/backlight/da903x.c

+/*
+ * Backlight driver for Dialog Semiconductor DA9030/DA9034
+ *
+ * Copyright (C) 2008 Compulab, Ltd.
+ * 	Mike Rapoport <mike@compulab.co.il>
+ *
+ * Copyright (C) 2006-2008 Marvell International Ltd.
+ * 	Eric Miao <eric.miao@marvell.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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/fb.h>
+#include <linux/backlight.h>
+#include <linux/mfd/da903x.h>
+
+#define DA9030_WLED_CONTROL	0x25
+#define DA9030_WLED_CP_EN	(1 << 6)
+#define DA9030_WLED_TRIM(x)	((x) & 0x7)
+
+#define DA9034_WLED_CONTROL1	0x3C
+#define DA9034_WLED_CONTROL2	0x3D
+
+#define DA9034_WLED_BOOST_EN	(1 << 5)
+
+#define DA9030_MAX_BRIGHTNESS	7
+#define DA9034_MAX_BRIGHTNESS	0x7f
+
+struct da903x_backlight_data {
+	struct device *da903x_dev;
+	int id;
+	int current_brightness;
+};
+
+static int da903x_backlight_set(struct backlight_device *bl, int brightness)
+{
+	struct da903x_backlight_data *data = bl_get_data(bl);
+	struct device *dev = data->da903x_dev;
+	uint8_t val;
+	int ret = 0;
+
+	switch (data->id) {
+	case DA9034_ID_WLED:
+		ret = da903x_update(dev, DA9034_WLED_CONTROL1,
+				brightness, 0x7f);
+		if (ret)
+			return ret;
+
+		if (data->current_brightness && brightness == 0)
+			ret = da903x_clr_bits(dev,
+					DA9034_WLED_CONTROL2,
+					DA9034_WLED_BOOST_EN);
+
+		if (data->current_brightness == 0 && brightness)
+			ret = da903x_set_bits(dev,
+					DA9034_WLED_CONTROL2,
+					DA9034_WLED_BOOST_EN);
+		break;
+	case DA9030_ID_WLED:
+		val = DA9030_WLED_TRIM(brightness);
+		val |= brightness ? DA9030_WLED_CP_EN : 0;
+		ret = da903x_write(dev, DA9030_WLED_CONTROL, val);
+		break;
+	}
+
+	if (ret)
+		return ret;
+
+	data->current_brightness = brightness;
+	return 0;
+}
+
+static int da903x_backlight_update_status(struct backlight_device *bl)
+{
+	int brightness = bl->props.brightness;
+
+	if (bl->props.power != FB_BLANK_UNBLANK)
+		brightness = 0;
+
+	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
+		brightness = 0;
+
+	return da903x_backlight_set(bl, brightness);
+}
+
+static int da903x_backlight_get_brightness(struct backlight_device *bl)
+{
+	struct da903x_backlight_data *data = bl_get_data(bl);
+	return data->current_brightness;
+}
+
+static struct backlight_ops da903x_backlight_ops = {
+	.update_status	= da903x_backlight_update_status,
+	.get_brightness	= da903x_backlight_get_brightness,
+};
+
+static int da903x_backlight_probe(struct platform_device *pdev)
+{
+	struct da903x_backlight_data *data;
+	struct backlight_device *bl;
+	int max_brightness;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (data == NULL)
+		return -ENOMEM;
+
+	switch (pdev->id) {
+	case DA9030_ID_WLED:
+		max_brightness = DA9030_MAX_BRIGHTNESS;
+		break;
+	case DA9034_ID_WLED:
+		max_brightness = DA9034_MAX_BRIGHTNESS;
+		break;
+	default:
+		dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
+				pdev->id);
+		return -EINVAL;
+	}
+
+	data->id = pdev->id;
+	data->da903x_dev = pdev->dev.parent;
+	data->current_brightness = 0;
+
+	bl = backlight_device_register(pdev->name, data->da903x_dev,
+			data, &da903x_backlight_ops);
+	if (IS_ERR(bl)) {
+		dev_err(&pdev->dev, "failed to register backlight\n");
+		return PTR_ERR(bl);
+	}
+
+	bl->props.max_brightness = max_brightness;
+	bl->props.brightness = max_brightness;
+
+	platform_set_drvdata(pdev, bl);
+	backlight_update_status(bl);
+	return 0;
+}
+
+static int da903x_backlight_remove(struct platform_device *pdev)
+{
+	struct backlight_device *bl = platform_get_drvdata(pdev);
+	struct da903x_backlight_data *data = bl_get_data(bl);
+
+	backlight_device_unregister(bl);
+	kfree(data);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int da903x_backlight_suspend(struct platform_device *pdev,
+				 pm_message_t state)
+{
+	struct backlight_device *bl = platform_get_drvdata(pdev);
+	return da903x_backlight_set(bl, 0);
+}
+
+static int da903x_backlight_resume(struct platform_device *pdev)
+{
+	struct backlight_device *bl = platform_get_drvdata(pdev);
+
+	backlight_update_status(bl);
+	return 0;
+}
+#else
+#define da903x_backlight_suspend	NULL
+#define da903x_backlight_resume		NULL
+#endif
+
+static struct platform_driver da903x_backlight_driver = {
+	.driver		= {
+		.name	= "da903x-backlight",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= da903x_backlight_probe,
+	.remove		= da903x_backlight_remove,
+	.suspend	= da903x_backlight_suspend,
+	.resume		= da903x_backlight_resume,
+};
+
+static int __init da903x_backlight_init(void)
+{
+	return platform_driver_register(&da903x_backlight_driver);
+}
+module_init(da903x_backlight_init);
+
+static void __exit da903x_backlight_exit(void)
+{
+	platform_driver_unregister(&da903x_backlight_driver);
+}
+module_exit(da903x_backlight_exit);
+
+MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
+MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>"
+	      "Mike Rapoport <mike@compulab.co.il>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:da903x-backlight");