diff options
Diffstat (limited to 'drivers/video/backlight/lm3632_bl.c')
| -rwxr-xr-x | drivers/video/backlight/lm3632_bl.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/drivers/video/backlight/lm3632_bl.c b/drivers/video/backlight/lm3632_bl.c new file mode 100755 index 00000000..6ee1e757 --- /dev/null +++ b/drivers/video/backlight/lm3632_bl.c @@ -0,0 +1,395 @@ +/* + * TI LM3632 Backlight Driver + * + * Copyright 2015 Texas Instruments + * + * Author: Milo 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/delay.h> +#include <linux/err.h> +#include <linux/mfd/lm3632.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pwm.h> +#include <linux/slab.h> +//#include "./lm3632.h" + +#define LM3632_MAX_BRIGHTNESS 2047 + +#define DEFAULT_BL_NAME "lcd-backlight" + +enum lm3632_bl_ctrl_mode { + LMU_BL_I2C, + LMU_BL_PWM, +}; +struct lm3632_bl { + struct device *dev; + struct backlight_device *bl_dev; + + struct lm3632 *lm3632; + struct lm3632_backlight_platform_data *pdata; + enum lm3632_bl_ctrl_mode mode; + + struct pwm_device *pwm; +}; + +static int lm3632_bl_string_configure(struct lm3632_bl *lm3632_bl, int enable) +{ + u8 val; + + if (enable) { + if (lm3632_bl->pdata->is_full_strings) + val = LM3632_BL_TWO_STRINGS; + else + val = LM3632_BL_ONE_STRING; + } else { + val = 0; + } + + return lm3632_update_bits(lm3632_bl->lm3632, LM3632_REG_ENABLE, + LM3632_BL_STRING_MASK, val); +} + +static int lm3632_bl_enable(struct lm3632_bl *lm3632_bl, int enable) +{ + int ret; + + ret = lm3632_bl_string_configure(lm3632_bl, enable); + if (ret) { + dev_err(lm3632_bl->dev, + "Backlight string config error: %d\n", ret); + return ret; + } + + return lm3632_update_bits(lm3632_bl->lm3632, LM3632_REG_ENABLE, + LM3632_BL_EN_MASK, enable << LM3632_BL_EN_SHIFT); +} + +static void lm3632_bl_pwm_ctrl(struct lm3632_bl *lm3632_bl, int br, int max_br) +{ + unsigned int period; + unsigned int duty; + struct pwm_device *pwm; + + if (!lm3632_bl->pdata) + return; + + period = lm3632_bl->pdata->pwm_period; + duty = br * period / max_br; + + /* Request a PWM device with the consumer name */ + if (!lm3632_bl->pwm) { + pwm = devm_pwm_get(lm3632_bl->dev, "lm3632-backlight"); + if (IS_ERR(pwm)) { + dev_err(lm3632_bl->dev, "can not get PWM device\n"); + return; + } + lm3632_bl->pwm = pwm; + } + + pwm_config(lm3632_bl->pwm, duty, period); + if (duty) + pwm_enable(lm3632_bl->pwm); + else + pwm_disable(lm3632_bl->pwm); +} + +static int lm3632_bl_set_brightness(struct lm3632_bl *lm3632_bl, int val) +{ + u8 data; + int ret; + + + data = val & LM3632_BRT_LSB_MASK; + ret = lm3632_update_bits(lm3632_bl->lm3632, LM3632_REG_BRT_LSB, + LM3632_BRT_LSB_MASK, data); + if (ret) + return ret; + + data = (val >> LM3632_BRT_MSB_SHIFT) & 0xFF; + + return lm3632_write_byte(lm3632_bl->lm3632, LM3632_REG_BRT_MSB, + data); +} + +static int lm3632_bl_update_status(struct backlight_device *bl_dev) +{ + struct lm3632_bl *lm3632_bl = bl_get_data(bl_dev); + int brt; + int ret; + + + if (bl_dev->props.state & BL_CORE_SUSPENDED) + brt = 0; + else + brt = bl_dev->props.brightness; + + printk("zyun lm3632 update status=%d\n", brt); + + if (brt > 0) + ret = lm3632_bl_enable(lm3632_bl, 1); + else + ret = lm3632_bl_enable(lm3632_bl, 0); + + if (ret) + return ret; + + // we don't want to update brightness here + if (lm3632_bl->mode == LMU_BL_PWM) + lm3632_bl_pwm_ctrl(lm3632_bl, brt, + bl_dev->props.max_brightness); + else + ret = lm3632_bl_set_brightness(lm3632_bl, brt); + + return ret; +} + +static int lm3632_bl_get_brightness(struct backlight_device *bl_dev) +{ + return bl_dev->props.brightness; +} + +static const struct backlight_ops lm3632_bl_ops = { + .options = BL_CORE_SUSPENDRESUME, + .update_status = lm3632_bl_update_status, + .get_brightness = lm3632_bl_get_brightness, +}; + +static int lm3632_bl_register(struct lm3632_bl *lm3632_bl) +{ + struct backlight_device *bl_dev; + struct backlight_properties props; + struct lm3632_backlight_platform_data *pdata = lm3632_bl->pdata; + char name[20]; + + props.type = BACKLIGHT_PLATFORM; + props.brightness = 1637; + props.max_brightness = LM3632_MAX_BRIGHTNESS; + + if (!pdata || !pdata->name) + snprintf(name, sizeof(name), "%s", DEFAULT_BL_NAME); + else + snprintf(name, sizeof(name), "%s", pdata->name); + + bl_dev = backlight_device_register(name, lm3632_bl->dev, lm3632_bl, + &lm3632_bl_ops, &props); + if (IS_ERR(bl_dev)) + return PTR_ERR(bl_dev); + + lm3632_bl->bl_dev = bl_dev; + + return 0; +} + +static void lm3632_bl_unregister(struct lm3632_bl *lm3632_bl) +{ + if (lm3632_bl->bl_dev) + backlight_device_unregister(lm3632_bl->bl_dev); +} + +static int lm3632_bl_set_ovp(struct lm3632_bl *lm3632_bl) +{ + return lm3632_update_bits(lm3632_bl->lm3632, LM3632_REG_CONFIG1, + LM3632_OVP_MASK, LM3632_OVP_25V); +} + +static int lm3632_bl_set_swfreq(struct lm3632_bl *lm3632_bl) +{ + return lm3632_update_bits(lm3632_bl->lm3632, LM3632_REG_CONFIG2, + LM3632_SWFREQ_MASK, LM3632_SWFREQ_1MHZ); +} + +static int lm3632_bl_bias_output(struct lm3632_bl *lm3632_bl) +{ + return lm3632_update_bits(lm3632_bl->lm3632, 0x0C, + BIT(0), BIT(0)); +} + + +static int lm3632_bl_set_ctrl_mode(struct lm3632_bl *lm3632_bl) +{ + struct lm3632_backlight_platform_data *pdata = lm3632_bl->pdata; +#if 0 + if (pdata->pwm_period > 0) + lm3632_bl->mode = LMU_BL_PWM; + else +#endif + lm3632_bl->mode = LMU_BL_I2C; + + return lm3632_update_bits(lm3632_bl->lm3632, LM3632_REG_IO_CTRL, + LM3632_PWM_MASK, + lm3632_bl->mode << LM3632_PWM_SHIFT); +} + +static int lm3632_bl_configure(struct lm3632_bl *lm3632_bl) +{ + int ret; + + /* Select OVP level */ + ret = lm3632_bl_set_ovp(lm3632_bl); + if (ret) + return ret; + + /* Select switch frequency */ + ret = lm3632_bl_set_swfreq(lm3632_bl); + if (ret) + return ret; + + /* Set vpos/vneg out */ + ret = lm3632_bl_bias_output(lm3632_bl); + if (ret) + return ret; + /* Backlight control mode - PWM or I2C */ + return lm3632_bl_set_ctrl_mode(lm3632_bl); +} + +static int lm3632_bl_parse_dt(struct device *dev, struct lm3632_bl *lm3632_bl) +{ + struct device_node *node = dev->of_node; + struct lm3632_backlight_platform_data *pdata; + int brightness = 0; + int ret; + + pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + + /* Channel name */ + of_property_read_string(node, "bl-name", &pdata->name); + + /* String configuration */ + if (of_find_property(node, "full-strings-used", NULL)) + pdata->is_full_strings = true; + + /* PWM mode */ + of_property_read_u32(node, "pwm-period", &pdata->pwm_period); + of_property_read_u32(node, "pwm-max-brightness", &brightness); + + if (pdata->pwm_period > 0) { + if (brightness == 0) { + dev_err(lm3632_bl->dev, + "PWM max brightness should be greater than 0\n"); + return -EINVAL; + } + + ret = lm3632_bl_set_brightness(lm3632_bl, brightness); + if (ret) { + dev_err(lm3632_bl->dev, + "PWM max brightness set error: %d\n", ret); + return ret; + } + } + + lm3632_bl->pdata = pdata; + + return 0; +} + +static int lm3632_bl_probe(struct platform_device *pdev) +{ + struct lm3632 *lm3632 = dev_get_drvdata(pdev->dev.parent); + struct lm3632_backlight_platform_data *pdata = lm3632->pdata->bl_pdata; + struct lm3632_bl *lm3632_bl; + int ret; + printk("zyun lm3632_bl_probe\n"); + printk("zyun get lm3632 adress=0x%x\n",(int)lm3632); + lm3632_bl = devm_kzalloc(&pdev->dev, sizeof(*lm3632_bl), GFP_KERNEL); + if (!lm3632_bl) + return -ENOMEM; + + lm3632_bl->dev = &pdev->dev; + lm3632_bl->lm3632 = lm3632; + lm3632_bl->pdata = pdata; + + if (!lm3632_bl->pdata) { + if (IS_ENABLED(CONFIG_OF)) + ret = lm3632_bl_parse_dt(&pdev->dev, lm3632_bl); + else + return -ENODEV; + + if (ret) + return ret; + } + + platform_set_drvdata(pdev, lm3632_bl); + + /* Backlight configuration */ + ret = lm3632_bl_configure(lm3632_bl); + if (ret) { + dev_err(&pdev->dev, "backlight config err: %d\n", ret); + return ret; + } + + if (gpio_request(52, "LCD_3V3")) { + printk("Failed ro request GPIO_%d \n",52); + return -ENODEV; + } + if (gpio_request(53, "CABC_EN1")) { + printk("Failed ro request GPIO_%d \n",53); + return -ENODEV; + } + + gpio_direction_output(53, 0); + gpio_direction_output(52, 0); + gpio_set_value(53,0); + gpio_set_value(52,0); + + gpio_set_value(53,1); + mdelay(5); + gpio_set_value(52,1); + + /* Register backlight subsystem */ + ret = lm3632_bl_register(lm3632_bl); + if (ret) { + dev_err(&pdev->dev, "register backlight err: %d\n", ret); + return ret; + } + + backlight_update_status(lm3632_bl->bl_dev); + + return 0; +} + +static int lm3632_bl_remove(struct platform_device *pdev) +{ + struct lm3632_bl *lm3632_bl = platform_get_drvdata(pdev); + struct backlight_device *bl_dev = lm3632_bl->bl_dev; + + bl_dev->props.brightness = 0; + backlight_update_status(bl_dev); + lm3632_bl_unregister(lm3632_bl); + + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id lm3632_bl_of_match[] = { + { .compatible = "ti,lm3632-backlight", }, + { } +}; +MODULE_DEVICE_TABLE(of, lm3632_bl_of_match); +#endif + +static struct platform_driver lm3632_bl_driver = { + .probe = lm3632_bl_probe, + .remove = lm3632_bl_remove, + .driver = { + .name = "lm3632-backlight", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(lm3632_bl_of_match), + }, +}; +module_platform_driver(lm3632_bl_driver); + +MODULE_DESCRIPTION("TI LM3632 Backlight Driver"); +MODULE_AUTHOR("Milo Kim"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:lm3632-backlight"); |