| /* |
| * 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/slab.h> |
| #include <linux/fb.h> |
| #include <linux/i2c.h> |
| #include <linux/backlight.h> |
| #include <linux/mfd/88pm860x.h> |
| #include <linux/module.h> |
| |
| #define MAX_BRIGHTNESS (0xFF) |
| #define MIN_BRIGHTNESS (0) |
| |
| #define CURRENT_BITMASK (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_BITMASK, 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 const struct backlight_ops pm860x_backlight_ops = { |
| .options = BL_CORE_SUSPENDRESUME, |
| .update_status = pm860x_backlight_update_status, |
| .get_brightness = pm860x_backlight_get_brightness, |
| }; |
| |
| static int pm860x_backlight_probe(struct platform_device *pdev) |
| { |
| struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); |
| struct pm860x_backlight_pdata *pdata = NULL; |
| struct pm860x_backlight_data *data; |
| struct backlight_device *bl; |
| struct resource *res; |
| struct backlight_properties props; |
| 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; |
| } |
| |
| pdata = pdev->dev.platform_data; |
| 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 = pdata->flags; |
| if (data->port < 0) { |
| dev_err(&pdev->dev, "wrong platform data is assigned"); |
| kfree(data); |
| return -EINVAL; |
| } |
| |
| memset(&props, 0, sizeof(struct backlight_properties)); |
| props.type = BACKLIGHT_RAW; |
| props.max_brightness = MAX_BRIGHTNESS; |
| bl = backlight_device_register(name, &pdev->dev, data, |
| &pm860x_backlight_ops, &props); |
| if (IS_ERR(bl)) { |
| dev_err(&pdev->dev, "failed to register backlight\n"); |
| kfree(data); |
| return PTR_ERR(bl); |
| } |
| 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: |
| backlight_device_unregister(bl); |
| 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"); |