diff options
Diffstat (limited to 'drivers/leds/leds-mt6323.c')
| -rw-r--r-- | drivers/leds/leds-mt6323.c | 502 |
1 files changed, 502 insertions, 0 deletions
diff --git a/drivers/leds/leds-mt6323.c b/drivers/leds/leds-mt6323.c new file mode 100644 index 000000000000..48081bccbea5 --- /dev/null +++ b/drivers/leds/leds-mt6323.c @@ -0,0 +1,502 @@ +/* + * LED driver for Mediatek MT6323 PMIC + * + * Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#include <linux/kernel.h> +#include <linux/leds.h> +#include <linux/mfd/mt6323/registers.h> +#include <linux/mfd/mt6397/core.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +/* + * Register field for MT6323_TOP_CKPDN0 to enable + * 32K clock common for LED device. + */ +#define MT6323_RG_DRV_32K_CK_PDN BIT(11) +#define MT6323_RG_DRV_32K_CK_PDN_MASK BIT(11) + +/* + * Register field for MT6323_TOP_CKPDN2 to enable + * individual clock for LED device. + */ +#define MT6323_RG_ISINK_CK_PDN(i) BIT(i) +#define MT6323_RG_ISINK_CK_PDN_MASK(i) BIT(i) + +/* + * Register field for MT6323_TOP_CKCON1 to select + * clock source. + */ +#define MT6323_RG_ISINK_CK_SEL_MASK(i) (BIT(10) << (i)) + +/* + * Register for MT6323_ISINK_CON0 to setup the + * duty cycle of the blink. + */ +#define MT6323_ISINK_CON0(i) (MT6323_ISINK0_CON0 + 0x8 * (i)) +#define MT6323_ISINK_DIM_DUTY_MASK (0x1f << 8) +#define MT6323_ISINK_DIM_DUTY(i) (((i) << 8) & \ + MT6323_ISINK_DIM_DUTY_MASK) + +/* Register to setup the period of the blink. */ +#define MT6323_ISINK_CON1(i) (MT6323_ISINK0_CON1 + 0x8 * (i)) +#define MT6323_ISINK_DIM_FSEL_MASK (0xffff) +#define MT6323_ISINK_DIM_FSEL(i) ((i) & MT6323_ISINK_DIM_FSEL_MASK) + +/* Register to control the brightness. */ +#define MT6323_ISINK_CON2(i) (MT6323_ISINK0_CON2 + 0x8 * (i)) +#define MT6323_ISINK_CH_STEP_SHIFT 12 +#define MT6323_ISINK_CH_STEP_MASK (0x7 << 12) +#define MT6323_ISINK_CH_STEP(i) (((i) << 12) & \ + MT6323_ISINK_CH_STEP_MASK) +#define MT6323_ISINK_SFSTR0_TC_MASK (0x3 << 1) +#define MT6323_ISINK_SFSTR0_TC(i) (((i) << 1) & \ + MT6323_ISINK_SFSTR0_TC_MASK) +#define MT6323_ISINK_SFSTR0_EN_MASK BIT(0) +#define MT6323_ISINK_SFSTR0_EN BIT(0) + +/* Register to LED channel enablement. */ +#define MT6323_ISINK_CH_EN_MASK(i) BIT(i) +#define MT6323_ISINK_CH_EN(i) BIT(i) + +#define MT6323_MAX_PERIOD 10000 +#define MT6323_MAX_LEDS 4 +#define MT6323_MAX_BRIGHTNESS 6 +#define MT6323_UNIT_DUTY 3125 +#define MT6323_CAL_HW_DUTY(o, p) DIV_ROUND_CLOSEST((o) * 100000ul,\ + (p) * MT6323_UNIT_DUTY) + +struct mt6323_leds; + +/** + * struct mt6323_led - state container for the LED device + * @id: the identifier in MT6323 LED device + * @parent: the pointer to MT6323 LED controller + * @cdev: LED class device for this LED device + * @current_brightness: current state of the LED device + */ +struct mt6323_led { + int id; + struct mt6323_leds *parent; + struct led_classdev cdev; + enum led_brightness current_brightness; +}; + +/** + * struct mt6323_leds - state container for holding LED controller + * of the driver + * @dev: the device pointer + * @hw: the underlying hardware providing shared + * bus for the register operations + * @lock: the lock among process context + * @led: the array that contains the state of individual + * LED device + */ +struct mt6323_leds { + struct device *dev; + struct mt6397_chip *hw; + /* protect among process context */ + struct mutex lock; + struct mt6323_led *led[MT6323_MAX_LEDS]; +}; + +static int mt6323_led_hw_brightness(struct led_classdev *cdev, + enum led_brightness brightness) +{ + struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev); + struct mt6323_leds *leds = led->parent; + struct regmap *regmap = leds->hw->regmap; + u32 con2_mask = 0, con2_val = 0; + int ret; + + /* + * Setup current output for the corresponding + * brightness level. + */ + con2_mask |= MT6323_ISINK_CH_STEP_MASK | + MT6323_ISINK_SFSTR0_TC_MASK | + MT6323_ISINK_SFSTR0_EN_MASK; + con2_val |= MT6323_ISINK_CH_STEP(brightness - 1) | + MT6323_ISINK_SFSTR0_TC(2) | + MT6323_ISINK_SFSTR0_EN; + + ret = regmap_update_bits(regmap, MT6323_ISINK_CON2(led->id), + con2_mask, con2_val); + return ret; +} + +static int mt6323_led_hw_off(struct led_classdev *cdev) +{ + struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev); + struct mt6323_leds *leds = led->parent; + struct regmap *regmap = leds->hw->regmap; + unsigned int status; + int ret; + + status = MT6323_ISINK_CH_EN(led->id); + ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL, + MT6323_ISINK_CH_EN_MASK(led->id), ~status); + if (ret < 0) + return ret; + + usleep_range(100, 300); + ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2, + MT6323_RG_ISINK_CK_PDN_MASK(led->id), + MT6323_RG_ISINK_CK_PDN(led->id)); + if (ret < 0) + return ret; + + return 0; +} + +static enum led_brightness +mt6323_get_led_hw_brightness(struct led_classdev *cdev) +{ + struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev); + struct mt6323_leds *leds = led->parent; + struct regmap *regmap = leds->hw->regmap; + unsigned int status; + int ret; + + ret = regmap_read(regmap, MT6323_TOP_CKPDN2, &status); + if (ret < 0) + return ret; + + if (status & MT6323_RG_ISINK_CK_PDN_MASK(led->id)) + return 0; + + ret = regmap_read(regmap, MT6323_ISINK_EN_CTRL, &status); + if (ret < 0) + return ret; + + if (!(status & MT6323_ISINK_CH_EN(led->id))) + return 0; + + ret = regmap_read(regmap, MT6323_ISINK_CON2(led->id), &status); + if (ret < 0) + return ret; + + return ((status & MT6323_ISINK_CH_STEP_MASK) + >> MT6323_ISINK_CH_STEP_SHIFT) + 1; +} + +static int mt6323_led_hw_on(struct led_classdev *cdev, + enum led_brightness brightness) +{ + struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev); + struct mt6323_leds *leds = led->parent; + struct regmap *regmap = leds->hw->regmap; + unsigned int status; + int ret; + + /* + * Setup required clock source, enable the corresponding + * clock and channel and let work with continuous blink as + * the default. + */ + ret = regmap_update_bits(regmap, MT6323_TOP_CKCON1, + MT6323_RG_ISINK_CK_SEL_MASK(led->id), 0); + if (ret < 0) + return ret; + + status = MT6323_RG_ISINK_CK_PDN(led->id); + ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2, + MT6323_RG_ISINK_CK_PDN_MASK(led->id), + ~status); + if (ret < 0) + return ret; + + usleep_range(100, 300); + + ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL, + MT6323_ISINK_CH_EN_MASK(led->id), + MT6323_ISINK_CH_EN(led->id)); + if (ret < 0) + return ret; + + ret = mt6323_led_hw_brightness(cdev, brightness); + if (ret < 0) + return ret; + + ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id), + MT6323_ISINK_DIM_DUTY_MASK, + MT6323_ISINK_DIM_DUTY(31)); + if (ret < 0) + return ret; + + ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id), + MT6323_ISINK_DIM_FSEL_MASK, + MT6323_ISINK_DIM_FSEL(1000)); + if (ret < 0) + return ret; + + return 0; +} + +static int mt6323_led_set_blink(struct led_classdev *cdev, + unsigned long *delay_on, + unsigned long *delay_off) +{ + struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev); + struct mt6323_leds *leds = led->parent; + struct regmap *regmap = leds->hw->regmap; + unsigned long period; + u8 duty_hw; + int ret; + + /* + * Units are in ms, if over the hardware able + * to support, fallback into software blink + */ + period = *delay_on + *delay_off; + + if (period > MT6323_MAX_PERIOD) + return -EINVAL; + + /* + * LED subsystem requires a default user + * friendly blink pattern for the LED so using + * 1Hz duty cycle 50% here if without specific + * value delay_on and delay off being assigned. + */ + if (!*delay_on && !*delay_off) { + *delay_on = 500; + *delay_off = 500; + } + + /* + * Calculate duty_hw based on the percentage of period during + * which the led is ON. + */ + duty_hw = MT6323_CAL_HW_DUTY(*delay_on, period); + + /* hardware doesn't support zero duty cycle. */ + if (!duty_hw) + return -EINVAL; + + mutex_lock(&leds->lock); + /* + * Set max_brightness as the software blink behavior + * when no blink brightness. + */ + if (!led->current_brightness) { + ret = mt6323_led_hw_on(cdev, cdev->max_brightness); + if (ret < 0) + goto out; + led->current_brightness = cdev->max_brightness; + } + + ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id), + MT6323_ISINK_DIM_DUTY_MASK, + MT6323_ISINK_DIM_DUTY(duty_hw - 1)); + if (ret < 0) + goto out; + + ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id), + MT6323_ISINK_DIM_FSEL_MASK, + MT6323_ISINK_DIM_FSEL(period - 1)); +out: + mutex_unlock(&leds->lock); + + return ret; +} + +static int mt6323_led_set_brightness(struct led_classdev *cdev, + enum led_brightness brightness) +{ + struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev); + struct mt6323_leds *leds = led->parent; + int ret; + + mutex_lock(&leds->lock); + + if (!led->current_brightness && brightness) { + ret = mt6323_led_hw_on(cdev, brightness); + if (ret < 0) + goto out; + } else if (brightness) { + ret = mt6323_led_hw_brightness(cdev, brightness); + if (ret < 0) + goto out; + } else { + ret = mt6323_led_hw_off(cdev); + if (ret < 0) + goto out; + } + + led->current_brightness = brightness; +out: + mutex_unlock(&leds->lock); + + return ret; +} + +static int mt6323_led_set_dt_default(struct led_classdev *cdev, + struct device_node *np) +{ + struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev); + const char *state; + int ret = 0; + + led->cdev.name = of_get_property(np, "label", NULL) ? : np->name; + led->cdev.default_trigger = of_get_property(np, + "linux,default-trigger", + NULL); + + state = of_get_property(np, "default-state", NULL); + if (state) { + if (!strcmp(state, "keep")) { + ret = mt6323_get_led_hw_brightness(cdev); + if (ret < 0) + return ret; + led->current_brightness = ret; + ret = 0; + } else if (!strcmp(state, "on")) { + ret = + mt6323_led_set_brightness(cdev, cdev->max_brightness); + } else { + ret = mt6323_led_set_brightness(cdev, LED_OFF); + } + } + + return ret; +} + +static int mt6323_led_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = pdev->dev.of_node; + struct device_node *child; + struct mt6397_chip *hw = dev_get_drvdata(pdev->dev.parent); + struct mt6323_leds *leds; + struct mt6323_led *led; + int ret; + unsigned int status; + u32 reg; + + leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL); + if (!leds) + return -ENOMEM; + + platform_set_drvdata(pdev, leds); + leds->dev = dev; + + /* + * leds->hw points to the underlying bus for the register + * controlled. + */ + leds->hw = hw; + mutex_init(&leds->lock); + + status = MT6323_RG_DRV_32K_CK_PDN; + ret = regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0, + MT6323_RG_DRV_32K_CK_PDN_MASK, ~status); + if (ret < 0) { + dev_err(leds->dev, + "Failed to update MT6323_TOP_CKPDN0 Register\n"); + return ret; + } + + for_each_available_child_of_node(np, child) { + ret = of_property_read_u32(child, "reg", ®); + if (ret) { + dev_err(dev, "Failed to read led 'reg' property\n"); + goto put_child_node; + } + + if (reg < 0 || reg > MT6323_MAX_LEDS || leds->led[reg]) { + dev_err(dev, "Invalid led reg %u\n", reg); + ret = -EINVAL; + goto put_child_node; + } + + led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL); + if (!led) { + ret = -ENOMEM; + goto put_child_node; + } + + leds->led[reg] = led; + leds->led[reg]->id = reg; + leds->led[reg]->cdev.max_brightness = MT6323_MAX_BRIGHTNESS; + leds->led[reg]->cdev.brightness_set_blocking = + mt6323_led_set_brightness; + leds->led[reg]->cdev.blink_set = mt6323_led_set_blink; + leds->led[reg]->cdev.brightness_get = + mt6323_get_led_hw_brightness; + leds->led[reg]->parent = leds; + + ret = mt6323_led_set_dt_default(&leds->led[reg]->cdev, child); + if (ret < 0) { + dev_err(leds->dev, + "Failed to LED set default from devicetree\n"); + goto put_child_node; + } + + ret = devm_led_classdev_register(dev, &leds->led[reg]->cdev); + if (ret) { + dev_err(&pdev->dev, "Failed to register LED: %d\n", + ret); + goto put_child_node; + } + leds->led[reg]->cdev.dev->of_node = child; + } + + return 0; + +put_child_node: + of_node_put(child); + return ret; +} + +static int mt6323_led_remove(struct platform_device *pdev) +{ + struct mt6323_leds *leds = platform_get_drvdata(pdev); + int i; + + /* Turn the LEDs off on driver removal. */ + for (i = 0 ; leds->led[i] ; i++) + mt6323_led_hw_off(&leds->led[i]->cdev); + + regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0, + MT6323_RG_DRV_32K_CK_PDN_MASK, + MT6323_RG_DRV_32K_CK_PDN); + + mutex_destroy(&leds->lock); + + return 0; +} + +static const struct of_device_id mt6323_led_dt_match[] = { + { .compatible = "mediatek,mt6323-led" }, + {}, +}; +MODULE_DEVICE_TABLE(of, mt6323_led_dt_match); + +static struct platform_driver mt6323_led_driver = { + .probe = mt6323_led_probe, + .remove = mt6323_led_remove, + .driver = { + .name = "mt6323-led", + .of_match_table = mt6323_led_dt_match, + }, +}; + +module_platform_driver(mt6323_led_driver); + +MODULE_DESCRIPTION("LED driver for Mediatek MT6323 PMIC"); +MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>"); +MODULE_LICENSE("GPL"); |
