TI LP8788 PMU has the backlight driver. The brightness can be controlled by the PWM or the I2C commands. Configurable parameters can be defined in the platform data.
Signed-off-by: Milo(Woogyom) Kim <[email protected]> --- drivers/video/backlight/Kconfig | 6 + drivers/video/backlight/Makefile | 1 + drivers/video/backlight/lp8788_bl.c | 325 +++++++++++++++++++++++++++++++++++ 3 files changed, 332 insertions(+), 0 deletions(-) create mode 100644 drivers/video/backlight/lp8788_bl.c diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index cf28276..6fe0231 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -359,6 +359,12 @@ config BACKLIGHT_LP855X This supports TI LP8550, LP8551, LP8552, LP8553 and LP8556 backlight driver. +config BACKLIGHT_LP8788 + tristate "Backlight driver for TI LP8788 MFD" + depends on BACKLIGHT_CLASS_DEVICE && MFD_LP8788 + help + This supports TI LP8788 backlight driver. + config BACKLIGHT_OT200 tristate "Backlight driver for ot200 visualisation device" depends on BACKLIGHT_CLASS_DEVICE && CS5535_MFGPT && GPIO_CS5535 diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index a2ac9cf..f8cc7cb 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -24,6 +24,7 @@ obj-$(CONFIG_BACKLIGHT_HP680) += hp680_bl.o obj-$(CONFIG_BACKLIGHT_LM3533) += lm3533_bl.o obj-$(CONFIG_BACKLIGHT_LOCOMO) += locomolcd.o obj-$(CONFIG_BACKLIGHT_LP855X) += lp855x_bl.o +obj-$(CONFIG_BACKLIGHT_LP8788) += lp8788_bl.o obj-$(CONFIG_BACKLIGHT_OMAP1) += omap1_bl.o obj-$(CONFIG_BACKLIGHT_PANDORA) += pandora_bl.o obj-$(CONFIG_BACKLIGHT_PROGEAR) += progear_bl.o diff --git a/drivers/video/backlight/lp8788_bl.c b/drivers/video/backlight/lp8788_bl.c new file mode 100644 index 0000000..1c803ad --- /dev/null +++ b/drivers/video/backlight/lp8788_bl.c @@ -0,0 +1,325 @@ +/* + * TI LP8788 MFD - backlight driver + * + * Copyright 2012 Texas Instruments + * + * Author: Milo(Woogyom) Kim <[email protected]> + * + * 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/module.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/platform_device.h> +#include <linux/backlight.h> +#include <linux/mfd/lp8788.h> + +/* register address */ +#define LP8788_BL_CONFIG 0x96 +#define LP8788_BL_BRIGHTNESS 0x97 +#define LP8788_BL_RAMP 0x98 + +/* mask/shift bits */ +#define LP8788_BL_I2C_EN BIT(0) /* Addr 96h */ +#define LP8788_BL_PWM_EN BIT(5) +#define LP8788_BL_FULLSCALE_S 2 +#define LP8788_BL_DIM_MODE_S 1 +#define LP8788_BL_PWM_POLARITY_S 6 +#define LP8788_BL_RAMP_RISE_S 4 /* Addr 98h */ + +#define BUF_SIZE 20 +#define MAX_BRIGHTNESS 127 +#define DEFAULT_BL_NAME "lcd-backlight" + +struct lp8788_bl_config { + enum lp8788_bl_ctrl_mode bl_mode; + enum lp8788_bl_dim_mode dim_mode; + enum lp8788_bl_full_scale_current full_scale; + enum lp8788_bl_ramp_step rise_time; + enum lp8788_bl_ramp_step fall_time; + enum lp8788_bl_pwm_polarity pwm_pol; +}; + +struct lp8788_bl { + struct lp8788 *lp; + struct backlight_device *bl_dev; + struct lp8788_backlight_platform_data *pdata; + enum lp8788_bl_ctrl_mode mode; +}; + +struct lp8788_bl_config default_bl_config = { + .bl_mode = LP8788_BL_REGISTER_ONLY, + .dim_mode = LP8788_DIM_EXPONENTIAL, + .full_scale = LP8788_FULLSCALE_1900uA, + .rise_time = LP8788_RAMP_8192us, + .fall_time = LP8788_RAMP_8192us, + .pwm_pol = LP8788_PWM_ACTIVE_HIGH, +}; + +static inline bool is_brightness_ctrl_by_pwm(enum lp8788_bl_ctrl_mode mode) +{ + return (mode == LP8788_BL_COMB_PWM_BASED); +} + +static inline bool is_brightness_ctrl_by_register(enum lp8788_bl_ctrl_mode mode) +{ + return (mode == LP8788_BL_REGISTER_ONLY || + mode == LP8788_BL_COMB_REGISTER_BASED); +} + +static int lp8788_backlight_init_device(struct lp8788_bl *bl) +{ + struct lp8788_backlight_platform_data *pdata = bl->pdata; + struct lp8788_bl_config *cfg = &default_bl_config; + int ret; + u8 val; + + /* update if platform data exists */ + if (pdata) { + cfg->bl_mode = pdata->bl_mode; + cfg->dim_mode = pdata->dim_mode; + cfg->full_scale = pdata->full_scale; + cfg->rise_time = pdata->rise_time; + cfg->fall_time = pdata->fall_time; + cfg->pwm_pol = pdata->pwm_pol; + } + + val = (cfg->rise_time << LP8788_BL_RAMP_RISE_S) | cfg->fall_time; + ret = lp8788_write_byte(bl->lp, LP8788_BL_RAMP, val); + if (ret) + return ret; + + val = (cfg->full_scale << LP8788_BL_FULLSCALE_S) | + (cfg->dim_mode << LP8788_BL_DIM_MODE_S); + + switch (cfg->bl_mode) { + case LP8788_BL_REGISTER_ONLY: + val |= LP8788_BL_I2C_EN; + break; + case LP8788_BL_COMB_PWM_BASED: + case LP8788_BL_COMB_REGISTER_BASED: + val |= LP8788_BL_I2C_EN; + val |= LP8788_BL_PWM_EN; + val |= cfg->pwm_pol << LP8788_BL_PWM_POLARITY_S; + break; + default: + dev_err(bl->lp->dev, "invalid mode: %d\n", cfg->bl_mode); + return -EINVAL; + } + + bl->mode = cfg->bl_mode; + + return lp8788_write_byte(bl->lp, LP8788_BL_CONFIG, val); +} + +static int lp8788_bl_update_status(struct backlight_device *bl_dev) +{ + struct lp8788_bl *bl = bl_get_data(bl_dev); + enum lp8788_bl_ctrl_mode mode = bl->mode; + + if (bl_dev->props.state & BL_CORE_SUSPENDED) + bl_dev->props.brightness = 0; + + if (is_brightness_ctrl_by_pwm(mode)) { + struct lp8788_bl_pwm_data *pd; + int brt = bl_dev->props.brightness; + int max = bl_dev->props.max_brightness; + + pd = bl->pdata ? &bl->pdata->pwm_data : NULL; + if (pd && pd->pwm_set_intensity) + pd->pwm_set_intensity(brt, max); + } else if (is_brightness_ctrl_by_register(mode)) { + u8 brt = bl_dev->props.brightness; + + lp8788_write_byte(bl->lp, LP8788_BL_BRIGHTNESS, brt); + } + + return 0; +} + +static int lp8788_bl_get_brightness(struct backlight_device *bl_dev) +{ + struct lp8788_bl *bl = bl_get_data(bl_dev); + enum lp8788_bl_ctrl_mode mode = bl->mode; + + if (is_brightness_ctrl_by_pwm(mode)) { + struct lp8788_bl_pwm_data *pd; + int max = bl_dev->props.max_brightness; + + pd = bl->pdata ? &bl->pdata->pwm_data : NULL; + if (pd && pd->pwm_get_intensity) + bl_dev->props.brightness = pd->pwm_get_intensity(max); + } else if (is_brightness_ctrl_by_register(mode)) { + u8 val = 0; + + lp8788_read_byte(bl->lp, LP8788_BL_BRIGHTNESS, &val); + bl_dev->props.brightness = val; + } + + return bl_dev->props.brightness; +} + +static const struct backlight_ops lp8788_bl_ops = { + .options = BL_CORE_SUSPENDRESUME, + .update_status = lp8788_bl_update_status, + .get_brightness = lp8788_bl_get_brightness, +}; + +static int lp8788_backlight_register(struct lp8788_bl *bl) +{ + struct backlight_device *bl_dev; + struct backlight_properties props; + struct lp8788_backlight_platform_data *pdata = bl->pdata; + int init_brt = pdata ? pdata->initial_brightness : 0; + char *name; + + props.type = BACKLIGHT_PLATFORM; + props.max_brightness = MAX_BRIGHTNESS; + + if (init_brt > props.max_brightness) + init_brt = props.max_brightness; + + props.brightness = init_brt; + + if (!pdata || !pdata->name) + name = DEFAULT_BL_NAME; + else + name = pdata->name; + + bl_dev = backlight_device_register(name, bl->lp->dev, bl, + &lp8788_bl_ops, &props); + if (IS_ERR(bl_dev)) + return PTR_ERR(bl_dev); + + bl->bl_dev = bl_dev; + + return 0; +} + +static void lp8788_backlight_unregister(struct lp8788_bl *bl) +{ + struct backlight_device *bl_dev = bl->bl_dev; + + if (bl_dev) + backlight_device_unregister(bl_dev); +} + +static ssize_t lp8788_get_bl_ctl_mode(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct lp8788_bl *bl = dev_get_drvdata(dev); + enum lp8788_bl_ctrl_mode mode = bl->mode; + char *strmode = NULL; + + switch (mode) { + case LP8788_BL_COMB_PWM_BASED: + strmode = "pwm based"; + break; + case LP8788_BL_REGISTER_ONLY: + case LP8788_BL_COMB_REGISTER_BASED: + strmode = "register based"; + break; + default: + strmode = "invalid mode"; + break; + } + + return scnprintf(buf, BUF_SIZE, "%s\n", strmode); +} + +static DEVICE_ATTR(bl_ctl_mode, S_IRUGO, lp8788_get_bl_ctl_mode, NULL); + +static struct attribute *lp8788_attributes[] = { + &dev_attr_bl_ctl_mode.attr, + NULL, +}; + +static const struct attribute_group lp8788_attr_group = { + .attrs = lp8788_attributes, +}; + +static __devinit int lp8788_backlight_probe(struct platform_device *pdev) +{ + struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent); + struct lp8788_bl *bl; + int ret; + + bl = devm_kzalloc(lp->dev, sizeof(struct lp8788_bl), GFP_KERNEL); + if (!bl) + return -ENOMEM; + + bl->lp = lp; + bl->pdata = lp->pdata ? lp->pdata->bl_pdata : NULL; + platform_set_drvdata(pdev, bl); + + ret = lp8788_backlight_init_device(bl); + if (ret) { + dev_err(lp->dev, "backlight init device err: %d\n", ret); + if (is_brightness_ctrl_by_register(bl->mode)) + goto err_dev; + } + + ret = lp8788_backlight_register(bl); + if (ret) { + dev_err(lp->dev, "register backlight err: %d\n", ret); + goto err_dev; + } + + ret = sysfs_create_group(&pdev->dev.kobj, &lp8788_attr_group); + if (ret) { + dev_err(lp->dev, "register sysfs err: %d\n", ret); + goto err_sysfs; + } + + backlight_update_status(bl->bl_dev); + return 0; + +err_sysfs: + lp8788_backlight_unregister(bl); +err_dev: + return ret; +} + +static int __devexit lp8788_backlight_remove(struct platform_device *pdev) +{ + struct lp8788_bl *bl = platform_get_drvdata(pdev); + struct backlight_device *bl_dev = bl->bl_dev; + + bl_dev->props.brightness = 0; + backlight_update_status(bl_dev); + sysfs_remove_group(&pdev->dev.kobj, &lp8788_attr_group); + lp8788_backlight_unregister(bl); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static struct platform_driver lp8788_bl_driver = { + .probe = lp8788_backlight_probe, + .remove = __devexit_p(lp8788_backlight_remove), + .driver = { + .name = LP8788_DEV_BACKLIGHT, + .owner = THIS_MODULE, + }, +}; + +static int __init lp8788_backlight_init(void) +{ + return platform_driver_register(&lp8788_bl_driver); +} +module_init(lp8788_backlight_init); + +static void __exit lp8788_backlight_exit(void) +{ + platform_driver_unregister(&lp8788_bl_driver); +} +module_exit(lp8788_backlight_exit); + +MODULE_DESCRIPTION("Texas Instruments LP8788 Backlight Driver"); +MODULE_AUTHOR("Milo Kim"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:lp8788-backlight"); -- 1.7.2.5 Best Regards, Milo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
