diff options
| -rw-r--r-- | drivers/video/backlight/Kconfig | 6 | ||||
| -rw-r--r-- | drivers/video/backlight/Makefile | 1 | ||||
| -rw-r--r-- | drivers/video/backlight/lp8788_bl.c | 333 | ||||
| -rw-r--r-- | include/linux/mfd/lp8788.h | 24 |
4 files changed, 345 insertions, 19 deletions
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index be27b551473f..db10d0120d2b 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -384,6 +384,12 @@ config BACKLIGHT_LP855X This supports TI LP8550, LP8551, LP8552, LP8553, LP8556 and LP8557 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 4606c218e8e4..96c4d620c5ce 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -38,6 +38,7 @@ obj-$(CONFIG_BACKLIGHT_LM3630) += lm3630_bl.o obj-$(CONFIG_BACKLIGHT_LM3639) += lm3639_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_MAX8925) += max8925_bl.o obj-$(CONFIG_BACKLIGHT_OMAP1) += omap1_bl.o obj-$(CONFIG_BACKLIGHT_OT200) += ot200_bl.o diff --git a/drivers/video/backlight/lp8788_bl.c b/drivers/video/backlight/lp8788_bl.c new file mode 100644 index 000000000000..4bb8b4f140cf --- /dev/null +++ b/drivers/video/backlight/lp8788_bl.c @@ -0,0 +1,333 @@ +/* + * TI LP8788 MFD - backlight driver + * + * Copyright 2012 Texas Instruments + * + * Author: Milo(Woogyom) Kim <milo.kim@ti.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/backlight.h> +#include <linux/err.h> +#include <linux/mfd/lp8788.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pwm.h> +#include <linux/slab.h> + +/* Register address */ +#define LP8788_BL_CONFIG 0x96 +#define LP8788_BL_EN BIT(0) +#define LP8788_BL_PWM_INPUT_EN BIT(5) +#define LP8788_BL_FULLSCALE_SHIFT 2 +#define LP8788_BL_DIM_MODE_SHIFT 1 +#define LP8788_BL_PWM_POLARITY_SHIFT 6 + +#define LP8788_BL_BRIGHTNESS 0x97 + +#define LP8788_BL_RAMP 0x98 +#define LP8788_BL_RAMP_RISE_SHIFT 4 + +#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 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 pwm_device *pwm; +}; + +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 = PWM_POLARITY_NORMAL, +}; + +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_configure(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 chip configuration if platform data exists, + * otherwise use the default settings. + */ + 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; + } + + /* Brightness ramp up/down */ + val = (cfg->rise_time << LP8788_BL_RAMP_RISE_SHIFT) | cfg->fall_time; + ret = lp8788_write_byte(bl->lp, LP8788_BL_RAMP, val); + if (ret) + return ret; + + /* Fullscale current setting */ + val = (cfg->full_scale << LP8788_BL_FULLSCALE_SHIFT) | + (cfg->dim_mode << LP8788_BL_DIM_MODE_SHIFT); + + /* Brightness control mode */ + switch (cfg->bl_mode) { + case LP8788_BL_REGISTER_ONLY: + val |= LP8788_BL_EN; + break; + case LP8788_BL_COMB_PWM_BASED: + case LP8788_BL_COMB_REGISTER_BASED: + val |= LP8788_BL_EN | LP8788_BL_PWM_INPUT_EN | + (cfg->pwm_pol << LP8788_BL_PWM_POLARITY_SHIFT); + 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 void lp8788_pwm_ctrl(struct lp8788_bl *bl, int br, int max_br) +{ + unsigned int period; + unsigned int duty; + struct device *dev; + struct pwm_device *pwm; + + if (!bl->pdata) + return; + + period = bl->pdata->period_ns; + duty = br * period / max_br; + dev = bl->lp->dev; + + /* request PWM device with the consumer name */ + if (!bl->pwm) { + pwm = devm_pwm_get(dev, LP8788_DEV_BACKLIGHT); + if (IS_ERR(pwm)) { + dev_err(dev, "can not get PWM device\n"); + return; + } + + bl->pwm = pwm; + } + + pwm_config(bl->pwm, duty, period); + if (duty) + pwm_enable(bl->pwm); + else + pwm_disable(bl->pwm); +} + +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)) { + int brt = bl_dev->props.brightness; + int max = bl_dev->props.max_brightness; + + lp8788_pwm_ctrl(bl, 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) +{ + 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; + char *name; + + props.type = BACKLIGHT_PLATFORM; + props.max_brightness = MAX_BRIGHTNESS; + + /* Initial brightness */ + if (pdata) + init_brt = min_t(int, pdata->initial_brightness, + props.max_brightness); + else + init_brt = 0; + + props.brightness = init_brt; + + /* Backlight device name */ + 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; + + if (is_brightness_ctrl_by_pwm(mode)) + strmode = "PWM based"; + else if (is_brightness_ctrl_by_register(mode)) + strmode = "Register based"; + else + strmode = "Invalid mode"; + + return scnprintf(buf, PAGE_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 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; + if (lp->pdata) + bl->pdata = lp->pdata->bl_pdata; + + platform_set_drvdata(pdev, bl); + + ret = lp8788_backlight_configure(bl); + if (ret) { + dev_err(lp->dev, "backlight config err: %d\n", ret); + 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 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 = lp8788_backlight_remove, + .driver = { + .name = LP8788_DEV_BACKLIGHT, + .owner = THIS_MODULE, + }, +}; +module_platform_driver(lp8788_bl_driver); + +MODULE_DESCRIPTION("Texas Instruments LP8788 Backlight Driver"); +MODULE_AUTHOR("Milo Kim"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:lp8788-backlight"); diff --git a/include/linux/mfd/lp8788.h b/include/linux/mfd/lp8788.h index 2a32b16f79cb..786bf6679a28 100644 --- a/include/linux/mfd/lp8788.h +++ b/include/linux/mfd/lp8788.h @@ -16,6 +16,7 @@ #include <linux/gpio.h> #include <linux/irqdomain.h> +#include <linux/pwm.h> #include <linux/regmap.h> #define LP8788_DEV_BUCK "lp8788-buck" @@ -124,11 +125,6 @@ enum lp8788_bl_ramp_step { LP8788_RAMP_65538us, }; -enum lp8788_bl_pwm_polarity { - LP8788_PWM_ACTIVE_HIGH, - LP8788_PWM_ACTIVE_LOW, -}; - enum lp8788_isink_scale { LP8788_ISINK_SCALE_100mA, LP8788_ISINK_SCALE_120mA, @@ -229,16 +225,6 @@ struct lp8788_charger_platform_data { }; /* - * struct lp8788_bl_pwm_data - * @pwm_set_intensity : set duty of pwm - * @pwm_get_intensity : get current duty of pwm - */ -struct lp8788_bl_pwm_data { - void (*pwm_set_intensity) (int brightness, int max_brightness); - int (*pwm_get_intensity) (int max_brightness); -}; - -/* * struct lp8788_backlight_platform_data * @name : backlight driver name. (default: "lcd-backlight") * @initial_brightness : initial value of backlight brightness @@ -248,8 +234,8 @@ struct lp8788_bl_pwm_data { * @rise_time : brightness ramp up step time * @fall_time : brightness ramp down step time * @pwm_pol : pwm polarity setting when bl_mode is pwm based - * @pwm_data : platform specific pwm generation functions - * only valid when bl_mode is pwm based + * @period_ns : platform specific pwm period value. unit is nano. + Only valid when bl_mode is LP8788_BL_COMB_PWM_BASED */ struct lp8788_backlight_platform_data { char *name; @@ -259,8 +245,8 @@ struct lp8788_backlight_platform_data { 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_pwm_data pwm_data; + enum pwm_polarity pwm_pol; + unsigned int period_ns; }; /* |