--- /dev/null
+/*
+ * 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");
projects / platform / kernel / linux-rpi.git / commitdiff