diff options
Diffstat (limited to 'drivers/video/backlight/88pm860x_bl.c')
-rw-r--r-- | drivers/video/backlight/88pm860x_bl.c | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/drivers/video/backlight/88pm860x_bl.c b/drivers/video/backlight/88pm860x_bl.c new file mode 100644 index 00000000000..93e25c77aeb --- /dev/null +++ b/drivers/video/backlight/88pm860x_bl.c @@ -0,0 +1,306 @@ +/* + * 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; + 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; + } + + 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; + } + + memset(&props, 0, sizeof(struct backlight_properties)); + 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: + 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"); |