backlight: Enable backlight in 88pm860x

At most, three backlight device can be supported in 88pm860x driver.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 304 insertions, 0 deletions

diff --git a/drivers/video/backlight/88pm860x_bl.c b/drivers/video/backlight/88pm860x_bl.c
new file mode 100644
index 000000000000..b8f705cca438
--- /dev/null
+++ b/drivers/video/backlight/88pm860x_bl.c
@@ -0,0 +1,304 @@
+/*
+ * Backlight driver for Marvell Semiconductor 88PM8606
+ *
+ * Copyright (C) 2009 Marvell International Ltd.
+ *      Haojian Zhuang <haojian.zhuang@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/init.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/fb.h>
+#include <linux/i2c.h>
+#include <linux/backlight.h>
+#include <linux/mfd/88pm860x.h>
+
+#define MAX_BRIGHTNESS          (0xFF)
+#define MIN_BRIGHTNESS          (0)
+
+#define CURRENT_MASK            (0x1F << 1)
+
+struct pm860x_backlight_data {
+        struct pm860x_chip *chip;
+        struct i2c_client *i2c;
+        int     current_brightness;
+        int     port;
+        int     pwm;
+        int     iset;
+};
+
+static inline int wled_a(int port)
+{
+        int ret;
+
+        ret = ((port - PM8606_BACKLIGHT1) << 1) + 2;
+        return ret;
+}
+
+static inline int wled_b(int port)
+{
+        int ret;
+
+        ret = ((port - PM8606_BACKLIGHT1) << 1) + 3;
+        return ret;
+}
+
+/* WLED2 & WLED3 share the same IDC */
+static inline int wled_idc(int port)
+{
+        int ret;
+
+        switch (port) {
+        case PM8606_BACKLIGHT1:
+        case PM8606_BACKLIGHT2:
+                ret = ((port - PM8606_BACKLIGHT1) << 1) + 3;
+                break;
+        case PM8606_BACKLIGHT3:
+        default:
+                ret = ((port - PM8606_BACKLIGHT2) << 1) + 3;
+                break;
+        }
+        return ret;
+}
+
+static int pm860x_backlight_set(struct backlight_device *bl, int brightness)
+{
+        struct pm860x_backlight_data *data = bl_get_data(bl);
+        struct pm860x_chip *chip = data->chip;
+        unsigned char value;
+        int ret;
+
+        if (brightness > MAX_BRIGHTNESS)
+                value = MAX_BRIGHTNESS;
+        else
+                value = brightness;
+
+        ret = pm860x_reg_write(data->i2c, wled_a(data->port), value);
+        if (ret < 0)
+                goto out;
+
+        if ((data->current_brightness == 0) && brightness) {
+                if (data->iset) {
+                        ret = pm860x_set_bits(data->i2c, wled_idc(data->port),
+                                              CURRENT_MASK, data->iset);
+                        if (ret < 0)
+                                goto out;
+                }
+                if (data->pwm) {
+                        ret = pm860x_set_bits(data->i2c, PM8606_PWM,
+                                              PM8606_PWM_FREQ_MASK, data->pwm);
+                        if (ret < 0)
+                                goto out;
+                }
+                if (brightness == MAX_BRIGHTNESS) {
+                        /* set WLED_ON bit as 100% */
+                        ret = pm860x_set_bits(data->i2c, wled_b(data->port),
+                                              PM8606_WLED_ON, PM8606_WLED_ON);
+                }
+        } else {
+                if (brightness == MAX_BRIGHTNESS) {
+                        /* set WLED_ON bit as 100% */
+                        ret = pm860x_set_bits(data->i2c, wled_b(data->port),
+                                              PM8606_WLED_ON, PM8606_WLED_ON);
+                } else {
+                        /* clear WLED_ON bit since it's not 100% */
+                        ret = pm860x_set_bits(data->i2c, wled_b(data->port),
+                                              PM8606_WLED_ON, 0);
+                }
+        }
+        if (ret < 0)
+                goto out;
+
+        dev_dbg(chip->dev, "set brightness %d\n", value);
+        data->current_brightness = value;
+        return 0;
+out:
+        dev_dbg(chip->dev, "set brightness %d failure with return "
+                "value:%d\n", value, ret);
+        return ret;
+}
+
+static int pm860x_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;
+
+        if (bl->props.state & BL_CORE_SUSPENDED)
+                brightness = 0;
+
+        return pm860x_backlight_set(bl, brightness);
+}
+
+static int pm860x_backlight_get_brightness(struct backlight_device *bl)
+{
+        struct pm860x_backlight_data *data = bl_get_data(bl);
+        struct pm860x_chip *chip = data->chip;
+        int ret;
+
+        ret = pm860x_reg_read(data->i2c, wled_a(data->port));
+        if (ret < 0)
+                goto out;
+        data->current_brightness = ret;
+        dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
+        return data->current_brightness;
+out:
+        return -EINVAL;
+}
+
+static struct backlight_ops pm860x_backlight_ops = {
+        .options        = BL_CORE_SUSPENDRESUME,
+        .update_status  = pm860x_backlight_update_status,
+        .get_brightness = pm860x_backlight_get_brightness,
+};
+
+static int __check_device(struct pm860x_backlight_pdata *pdata, char *name)
+{
+        struct pm860x_backlight_pdata *p = pdata;
+        int ret = -EINVAL;
+
+        while (p && p->id) {
+                if ((p->id != PM8606_ID_BACKLIGHT) || (p->flags < 0))
+                        break;
+
+                if (!strncmp(name, pm860x_backlight_name[p->flags],
+                        MFD_NAME_SIZE)) {
+                        ret = (int)p->flags;
+                        break;
+                }
+                p++;
+        }
+        return ret;
+}
+
+static int pm860x_backlight_probe(struct platform_device *pdev)
+{
+        struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
+        struct pm860x_platform_data *pm860x_pdata;
+        struct pm860x_backlight_pdata *pdata = NULL;
+        struct pm860x_backlight_data *data;
+        struct backlight_device *bl;
+        struct resource *res;
+        unsigned char value;
+        char name[MFD_NAME_SIZE];
+        int ret;
+
+        res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+        if (res == NULL) {
+                dev_err(&pdev->dev, "No I/O resource!\n");
+                return -EINVAL;
+        }
+
+        if (pdev->dev.parent->platform_data) {
+                pm860x_pdata = pdev->dev.parent->platform_data;
+                pdata = pm860x_pdata->backlight;
+        }
+        if (pdata == NULL) {
+                dev_err(&pdev->dev, "platform data isn't assigned to "
+                        "backlight\n");
+                return -EINVAL;
+        }
+
+        data = kzalloc(sizeof(struct pm860x_backlight_data), GFP_KERNEL);
+        if (data == NULL)
+                return -ENOMEM;
+        strncpy(name, res->name, MFD_NAME_SIZE);
+        data->chip = chip;
+        data->i2c = (chip->id == CHIP_PM8606) ? chip->client    \
+                        : chip->companion;
+        data->current_brightness = MAX_BRIGHTNESS;
+        data->pwm = pdata->pwm;
+        data->iset = pdata->iset;
+        data->port = __check_device(pdata, name);
+        if (data->port < 0) {
+                dev_err(&pdev->dev, "wrong platform data is assigned");
+                return -EINVAL;
+        }
+
+        bl = backlight_device_register(name, &pdev->dev, data,
+                                        &pm860x_backlight_ops);
+        if (IS_ERR(bl)) {
+                dev_err(&pdev->dev, "failed to register backlight\n");
+                kfree(data);
+                return PTR_ERR(bl);
+        }
+        bl->props.max_brightness = MAX_BRIGHTNESS;
+        bl->props.brightness = MAX_BRIGHTNESS;
+
+        platform_set_drvdata(pdev, bl);
+
+        /* Enable reference VSYS */
+        ret = pm860x_reg_read(data->i2c, PM8606_VSYS);
+        if (ret < 0)
+                goto out;
+        if ((ret & PM8606_VSYS_EN) == 0) {
+                value = ret | PM8606_VSYS_EN;
+                ret = pm860x_reg_write(data->i2c, PM8606_VSYS, value);
+                if (ret < 0)
+                        goto out;
+        }
+        /* Enable reference OSC */
+        ret = pm860x_reg_read(data->i2c, PM8606_MISC);
+        if (ret < 0)
+                goto out;
+        if ((ret & PM8606_MISC_OSC_EN) == 0) {
+                value = ret | PM8606_MISC_OSC_EN;
+                ret = pm860x_reg_write(data->i2c, PM8606_MISC, value);
+                if (ret < 0)
+                        goto out;
+        }
+        /* read current backlight */
+        ret = pm860x_backlight_get_brightness(bl);
+        if (ret < 0)
+                goto out;
+
+        backlight_update_status(bl);
+        return 0;
+out:
+        kfree(data);
+        return ret;
+}
+
+static int pm860x_backlight_remove(struct platform_device *pdev)
+{
+        struct backlight_device *bl = platform_get_drvdata(pdev);
+        struct pm860x_backlight_data *data = bl_get_data(bl);
+
+        backlight_device_unregister(bl);
+        kfree(data);
+        return 0;
+}
+
+static struct platform_driver pm860x_backlight_driver = {
+        .driver         = {
+                .name   = "88pm860x-backlight",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = pm860x_backlight_probe,
+        .remove         = pm860x_backlight_remove,
+};
+
+static int __init pm860x_backlight_init(void)
+{
+        return platform_driver_register(&pm860x_backlight_driver);
+}
+module_init(pm860x_backlight_init);
+
+static void __exit pm860x_backlight_exit(void)
+{
+        platform_driver_unregister(&pm860x_backlight_driver);
+}
+module_exit(pm860x_backlight_exit);
+
+MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:88pm860x-backlight");