| /* |
| * 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/of.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; |
| int reg_duty_cycle; |
| int reg_always_on; |
| int reg_current; |
| }; |
| |
| static int backlight_power_set(struct pm860x_chip *chip, int port, |
| int on) |
| { |
| int ret = -EINVAL; |
| |
| switch (port) { |
| case 0: |
| ret = on ? pm8606_osc_enable(chip, WLED1_DUTY) : |
| pm8606_osc_disable(chip, WLED1_DUTY); |
| break; |
| case 1: |
| ret = on ? pm8606_osc_enable(chip, WLED2_DUTY) : |
| pm8606_osc_disable(chip, WLED2_DUTY); |
| break; |
| case 2: |
| ret = on ? pm8606_osc_enable(chip, WLED3_DUTY) : |
| pm8606_osc_disable(chip, WLED3_DUTY); |
| 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; |
| |
| if (brightness) |
| backlight_power_set(chip, data->port, 1); |
| |
| ret = pm860x_reg_write(data->i2c, data->reg_duty_cycle, value); |
| if (ret < 0) |
| goto out; |
| |
| if ((data->current_brightness == 0) && brightness) { |
| if (data->iset) { |
| ret = pm860x_set_bits(data->i2c, data->reg_current, |
| 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, data->reg_always_on, |
| PM8606_WLED_ON, PM8606_WLED_ON); |
| } |
| } else { |
| if (brightness == MAX_BRIGHTNESS) { |
| /* set WLED_ON bit as 100% */ |
| ret = pm860x_set_bits(data->i2c, data->reg_always_on, |
| PM8606_WLED_ON, PM8606_WLED_ON); |
| } else { |
| /* clear WLED_ON bit since it's not 100% */ |
| ret = pm860x_set_bits(data->i2c, data->reg_always_on, |
| PM8606_WLED_ON, 0); |
| } |
| } |
| if (ret < 0) |
| goto out; |
| |
| if (brightness == 0) |
| backlight_power_set(chip, data->port, 0); |
| |
| 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, data->reg_duty_cycle); |
| 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, |
| }; |
| |
| #ifdef CONFIG_OF |
| static int pm860x_backlight_dt_init(struct platform_device *pdev, |
| struct pm860x_backlight_data *data, |
| char *name) |
| { |
| struct device_node *nproot, *np; |
| int iset = 0; |
| |
| nproot = of_node_get(pdev->dev.parent->of_node); |
| if (!nproot) |
| return -ENODEV; |
| nproot = of_find_node_by_name(nproot, "backlights"); |
| if (!nproot) { |
| dev_err(&pdev->dev, "failed to find backlights node\n"); |
| return -ENODEV; |
| } |
| for_each_child_of_node(nproot, np) { |
| if (!of_node_cmp(np->name, name)) { |
| of_property_read_u32(np, "marvell,88pm860x-iset", |
| &iset); |
| data->iset = PM8606_WLED_CURRENT(iset); |
| of_property_read_u32(np, "marvell,88pm860x-pwm", |
| &data->pwm); |
| break; |
| } |
| } |
| of_node_put(nproot); |
| return 0; |
| } |
| #else |
| #define pm860x_backlight_dt_init(x, y, z) (-1) |
| #endif |
| |
| static int pm860x_backlight_probe(struct platform_device *pdev) |
| { |
| struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); |
| struct pm860x_backlight_pdata *pdata = dev_get_platdata(&pdev->dev); |
| struct pm860x_backlight_data *data; |
| struct backlight_device *bl; |
| struct resource *res; |
| struct backlight_properties props; |
| char name[MFD_NAME_SIZE]; |
| int ret = 0; |
| |
| data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data), |
| GFP_KERNEL); |
| if (data == NULL) |
| return -ENOMEM; |
| res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle"); |
| if (!res) { |
| dev_err(&pdev->dev, "No REG resource for duty cycle\n"); |
| return -ENXIO; |
| } |
| data->reg_duty_cycle = res->start; |
| res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on"); |
| if (!res) { |
| dev_err(&pdev->dev, "No REG resource for always on\n"); |
| return -ENXIO; |
| } |
| data->reg_always_on = res->start; |
| res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current"); |
| if (!res) { |
| dev_err(&pdev->dev, "No REG resource for current\n"); |
| return -ENXIO; |
| } |
| data->reg_current = res->start; |
| |
| memset(name, 0, MFD_NAME_SIZE); |
| sprintf(name, "backlight-%d", pdev->id); |
| data->port = pdev->id; |
| data->chip = chip; |
| data->i2c = (chip->id == CHIP_PM8606) ? chip->client : chip->companion; |
| data->current_brightness = MAX_BRIGHTNESS; |
| if (pm860x_backlight_dt_init(pdev, data, name)) { |
| if (pdata) { |
| data->pwm = pdata->pwm; |
| data->iset = pdata->iset; |
| } |
| } |
| |
| memset(&props, 0, sizeof(struct backlight_properties)); |
| props.type = BACKLIGHT_RAW; |
| props.max_brightness = MAX_BRIGHTNESS; |
| bl = devm_backlight_device_register(&pdev->dev, name, &pdev->dev, data, |
| &pm860x_backlight_ops, &props); |
| if (IS_ERR(bl)) { |
| dev_err(&pdev->dev, "failed to register backlight\n"); |
| return PTR_ERR(bl); |
| } |
| bl->props.brightness = MAX_BRIGHTNESS; |
| |
| platform_set_drvdata(pdev, bl); |
| |
| /* read current backlight */ |
| ret = pm860x_backlight_get_brightness(bl); |
| if (ret < 0) |
| return ret; |
| |
| backlight_update_status(bl); |
| return 0; |
| } |
| |
| static struct platform_driver pm860x_backlight_driver = { |
| .driver = { |
| .name = "88pm860x-backlight", |
| }, |
| .probe = pm860x_backlight_probe, |
| }; |
| |
| module_platform_driver(pm860x_backlight_driver); |
| |
| MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606"); |
| MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("platform:88pm860x-backlight"); |