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>

1 files changed, 201 insertions, 0 deletions

diff --git a/drivers/video/backlight/da903x.c b/drivers/video/backlight/da903x.c
new file mode 100644
index 000000000000..242c38250166
--- /dev/null
+++ b/drivers/video/backlight/da903x.c
@@ -0,0 +1,201 @@
+/*
+ * 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");