diff options
Diffstat (limited to 'drivers/video/backlight/88pm860x_bl.c')
| -rw-r--r-- | drivers/video/backlight/88pm860x_bl.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/drivers/video/backlight/88pm860x_bl.c b/drivers/video/backlight/88pm860x_bl.c new file mode 100644 index 000000000..6d8dc2c77 --- /dev/null +++ b/drivers/video/backlight/88pm860x_bl.c @@ -0,0 +1,275 @@ +/* + * 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_get_child_by_name(pdev->dev.parent->of_node, "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); + of_node_put(np); + 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"); |