linux/drivers/leds/leds-mt6323.c

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/*
* 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", &reg);
if (ret) {
dev_err(dev, "Failed to read led 'reg' property\n");
goto put_child_node;
}
if (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");