// SPDX-License-Identifier: GPL-2.0
/*
* Driver for LEDs connected to the Intel Cherry Trail Whiskey Cove PMIC
*
* Copyright 2019 Yauhen Kharuzhy <[email protected]>
* Copyright 2023 Hans de Goede <[email protected]>
*
* Register info comes from the Lenovo Yoga Book Android opensource code
* available from Lenovo. File lenovo_yb1_x90f_l_osc_201803.7z path in the 7z:
* YB1_source_code/kernel/cht/drivers/misc/charger_gp_led.c
*/
#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/mfd/intel_soc_pmic.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/suspend.h>
#define CHT_WC_LED1_CTRL 0x5e1f
#define CHT_WC_LED1_FSM 0x5e20
#define CHT_WC_LED1_PWM 0x5e21
#define CHT_WC_LED2_CTRL 0x4fdf
#define CHT_WC_LED2_FSM 0x4fe0
#define CHT_WC_LED2_PWM 0x4fe1
#define CHT_WC_LED1_SWCTL BIT(0) /* HW or SW control of charging led */
#define CHT_WC_LED1_ON BIT(1)
#define CHT_WC_LED2_ON BIT(0)
#define CHT_WC_LED_I_MA2_5 (2 << 2) /* LED current limit */
#define CHT_WC_LED_I_MASK GENMASK(3, 2) /* LED current limit mask */
#define CHT_WC_LED_F_1_4_HZ (0 << 4)
#define CHT_WC_LED_F_1_2_HZ (1 << 4)
#define CHT_WC_LED_F_1_HZ (2 << 4)
#define CHT_WC_LED_F_2_HZ (3 << 4)
#define CHT_WC_LED_F_MASK GENMASK(5, 4)
#define CHT_WC_LED_EFF_OFF (0 << 1)
#define CHT_WC_LED_EFF_ON (1 << 1)
#define CHT_WC_LED_EFF_BLINKING (2 << 1)
#define CHT_WC_LED_EFF_BREATHING (3 << 1)
#define CHT_WC_LED_EFF_MASK GENMASK(2, 1)
#define CHT_WC_LED_COUNT 2
struct cht_wc_led_regs {
/* Register addresses */
u16 ctrl;
u16 fsm;
u16 pwm;
/* Mask + values for turning the LED on/off */
u8 on_off_mask;
u8 on_val;
u8 off_val;
};
struct cht_wc_led_saved_regs {
unsigned int ctrl;
unsigned int fsm;
unsigned int pwm;
};
struct cht_wc_led {
struct led_classdev cdev;
const struct cht_wc_led_regs *regs;
struct regmap *regmap;
struct mutex mutex;
struct cht_wc_led_saved_regs saved_regs;
};
struct cht_wc_leds {
struct cht_wc_led leds[CHT_WC_LED_COUNT];
/* Saved LED1 initial register values */
struct cht_wc_led_saved_regs led1_initial_regs;
};
static const struct cht_wc_led_regs cht_wc_led_regs[CHT_WC_LED_COUNT] = {
{
.ctrl = CHT_WC_LED1_CTRL,
.fsm = CHT_WC_LED1_FSM,
.pwm = CHT_WC_LED1_PWM,
.on_off_mask = CHT_WC_LED1_SWCTL | CHT_WC_LED1_ON,
.on_val = CHT_WC_LED1_SWCTL | CHT_WC_LED1_ON,
.off_val = CHT_WC_LED1_SWCTL,
},
{
.ctrl = CHT_WC_LED2_CTRL,
.fsm = CHT_WC_LED2_FSM,
.pwm = CHT_WC_LED2_PWM,
.on_off_mask = CHT_WC_LED2_ON,
.on_val = CHT_WC_LED2_ON,
.off_val = 0,
},
};
static const char * const cht_wc_leds_names[CHT_WC_LED_COUNT] = {
"platform::" LED_FUNCTION_CHARGING,
"platform::" LED_FUNCTION_INDICATOR,
};
static int cht_wc_leds_brightness_set(struct led_classdev *cdev,
enum led_brightness value)
{
struct cht_wc_led *led = container_of(cdev, struct cht_wc_led, cdev);
int ret;
mutex_lock(&led->mutex);
if (!value) {
ret = regmap_update_bits(led->regmap, led->regs->ctrl,
led->regs->on_off_mask, led->regs->off_val);
if (ret < 0) {
dev_err(cdev->dev, "Failed to turn off: %d\n", ret);
goto out;
}
/* Disable HW blinking */
ret = regmap_update_bits(led->regmap, led->regs->fsm,
CHT_WC_LED_EFF_MASK, CHT_WC_LED_EFF_ON);
if (ret < 0)
dev_err(cdev->dev, "Failed to update LED FSM reg: %d\n", ret);
} else {
ret = regmap_write(led->regmap, led->regs->pwm, value);
if (ret < 0) {
dev_err(cdev->dev, "Failed to set brightness: %d\n", ret);
goto out;
}
ret = regmap_update_bits(led->regmap, led->regs->ctrl,
led->regs->on_off_mask, led->regs->on_val);
if (ret < 0)
dev_err(cdev->dev, "Failed to turn on: %d\n", ret);
}
out:
mutex_unlock(&led->mutex);
return ret;
}
static enum led_brightness cht_wc_leds_brightness_get(struct led_classdev *cdev)
{
struct cht_wc_led *led = container_of(cdev, struct cht_wc_led, cdev);
unsigned int val;
int ret;
mutex_lock(&led->mutex);
ret = regmap_read(led->regmap, led->regs->ctrl, &val);
if (ret < 0) {
dev_err(cdev->dev, "Failed to read LED CTRL reg: %d\n", ret);
ret = 0;
goto done;
}
val &= led->regs->on_off_mask;
if (val != led->regs->on_val) {
ret = 0;
goto done;
}
ret = regmap_read(led->regmap, led->regs->pwm, &val);
if (ret < 0) {
dev_err(cdev->dev, "Failed to read LED PWM reg: %d\n", ret);
ret = 0;
goto done;
}
ret = val;
done:
mutex_unlock(&led->mutex);
return ret;
}
/* Return blinking period for given CTRL reg value */
static unsigned long cht_wc_leds_get_period(int ctrl)
{
ctrl &= CHT_WC_LED_F_MASK;
switch (ctrl) {
case CHT_WC_LED_F_1_4_HZ:
return 1000 * 4;
case CHT_WC_LED_F_1_2_HZ:
return 1000 * 2;
case CHT_WC_LED_F_1_HZ:
return 1000;
case CHT_WC_LED_F_2_HZ:
return 1000 / 2;
}
return 0;
}
/*
* Find suitable hardware blink mode for given period.
* period < 750 ms - select 2 HZ
* 750 ms <= period < 1500 ms - select 1 HZ
* 1500 ms <= period < 3000 ms - select 1/2 HZ
* 3000 ms <= period < 5000 ms - select 1/4 HZ
* 5000 ms <= period - return -1
*/
static int cht_wc_leds_find_freq(unsigned long period)
{
if (period < 750)
return CHT_WC_LED_F_2_HZ;
else if (period < 1500)
return CHT_WC_LED_F_1_HZ;
else if (period < 3000)
return CHT_WC_LED_F_1_2_HZ;
else if (period < 5000)
return CHT_WC_LED_F_1_4_HZ;
else
return -1;
}
static int cht_wc_leds_set_effect(struct led_classdev *cdev,
unsigned long *delay_on,
unsigned long *delay_off,
u8 effect)
{
struct cht_wc_led *led = container_of(cdev, struct cht_wc_led, cdev);
int ctrl, ret;
mutex_lock(&led->mutex);
/* Blink with 1 Hz as default if nothing specified */
if (!*delay_on && !*delay_off)
*delay_on = *delay_off = 500;
ctrl = cht_wc_leds_find_freq(*delay_on + *delay_off);
if (ctrl < 0) {
/* Disable HW blinking */
ret = regmap_update_bits(led->regmap, led->regs->fsm,
CHT_WC_LED_EFF_MASK, CHT_WC_LED_EFF_ON);
if (ret < 0)
dev_err(cdev->dev, "Failed to update LED FSM reg: %d\n", ret);
/* Fallback to software timer */
*delay_on = *delay_off = 0;
ret = -EINVAL;
goto done;
}
ret = regmap_update_bits(led->regmap, led->regs->fsm,
CHT_WC_LED_EFF_MASK, effect);
if (ret < 0)
dev_err(cdev->dev, "Failed to update LED FSM reg: %d\n", ret);
/* Set the frequency and make sure the LED is on */
ret = regmap_update_bits(led->regmap, led->regs->ctrl,
CHT_WC_LED_F_MASK | led->regs->on_off_mask,
ctrl | led->regs->on_val);
if (ret < 0)
dev_err(cdev->dev, "Failed to update LED CTRL reg: %d\n", ret);
*delay_off = *delay_on = cht_wc_leds_get_period(ctrl) / 2;
done:
mutex_unlock(&led->mutex);
return ret;
}
static int cht_wc_leds_blink_set(struct led_classdev *cdev,
unsigned long *delay_on,
unsigned long *delay_off)
{
u8 effect = CHT_WC_LED_EFF_BLINKING;
/*
* The desired default behavior of LED1 / the charge LED is breathing
* while charging and on/solid when full. Since triggers cannot select
* breathing, blink_set() gets called when charging. Use slow breathing
* when the default "charging-blink-full-solid" trigger is used to
* achieve the desired default behavior.
*/
if (cdev->flags & LED_INIT_DEFAULT_TRIGGER) {
*delay_on = *delay_off = 1000;
effect = CHT_WC_LED_EFF_BREATHING;
}
return cht_wc_leds_set_effect(cdev, delay_on, delay_off, effect);
}
static int cht_wc_leds_pattern_set(struct led_classdev *cdev,
struct led_pattern *pattern,
u32 len, int repeat)
{
unsigned long delay_off, delay_on;
if (repeat > 0 || len != 2 ||
pattern[0].brightness != 0 || pattern[1].brightness != 1 ||
pattern[0].delta_t != pattern[1].delta_t ||
(pattern[0].delta_t != 250 && pattern[0].delta_t != 500 &&
pattern[0].delta_t != 1000 && pattern[0].delta_t != 2000))
return -EINVAL;
delay_off = pattern[0].delta_t;
delay_on = pattern[1].delta_t;
return cht_wc_leds_set_effect(cdev, &delay_on, &delay_off, CHT_WC_LED_EFF_BREATHING);
}
static int cht_wc_leds_pattern_clear(struct led_classdev *cdev)
{
return cht_wc_leds_brightness_set(cdev, 0);
}
static int cht_wc_led_save_regs(struct cht_wc_led *led,
struct cht_wc_led_saved_regs *saved_regs)
{
int ret;
ret = regmap_read(led->regmap, led->regs->ctrl, &saved_regs->ctrl);
if (ret < 0)
return ret;
ret = regmap_read(led->regmap, led->regs->fsm, &saved_regs->fsm);
if (ret < 0)
return ret;
return regmap_read(led->regmap, led->regs->pwm, &saved_regs->pwm);
}
static void cht_wc_led_restore_regs(struct cht_wc_led *led,
const struct cht_wc_led_saved_regs *saved_regs)
{
regmap_write(led->regmap, led->regs->ctrl, saved_regs->ctrl);
regmap_write(led->regmap, led->regs->fsm, saved_regs->fsm);
regmap_write(led->regmap, led->regs->pwm, saved_regs->pwm);
}
static int cht_wc_leds_probe(struct platform_device *pdev)
{
struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
struct cht_wc_leds *leds;
int ret;
int i;
/*
* On the Lenovo Yoga Tab 3 the LED1 driver output is actually
* connected to a haptic feedback motor rather then a LED.
* So do not register a LED classdev there (LED2 is unused).
*/
if (pmic->cht_wc_model == INTEL_CHT_WC_LENOVO_YT3_X90)
return -ENODEV;
leds = devm_kzalloc(&pdev->dev, sizeof(*leds), GFP_KERNEL);
if (!leds)
return -ENOMEM;
/*
* LED1 might be in hw-controlled mode when this driver gets loaded; and
* since the PMIC is always powered by the battery any changes made are
* permanent. Save LED1 regs to restore them on remove() or shutdown().
*/
leds->leds[0].regs = &cht_wc_led_regs[0];
leds->leds[0].regmap = pmic->regmap;
ret = cht_wc_led_save_regs(&leds->leds[0], &leds->led1_initial_regs);
if (ret < 0)
return ret;
/* Set LED1 default trigger based on machine model */
switch (pmic->cht_wc_model) {
case INTEL_CHT_WC_GPD_WIN_POCKET:
leds->leds[0].cdev.default_trigger = "max170xx_battery-charging-blink-full-solid";
break;
case INTEL_CHT_WC_XIAOMI_MIPAD2:
leds->leds[0].cdev.default_trigger = "bq27520-0-charging-blink-full-solid";
break;
case INTEL_CHT_WC_LENOVO_YOGABOOK1:
leds->leds[0].cdev.default_trigger = "bq27542-0-charging-blink-full-solid";
break;
default:
dev_warn(&pdev->dev, "Unknown model, no default charging trigger\n");
break;
}
for (i = 0; i < CHT_WC_LED_COUNT; i++) {
struct cht_wc_led *led = &leds->leds[i];
led->regs = &cht_wc_led_regs[i];
led->regmap = pmic->regmap;
mutex_init(&led->mutex);
led->cdev.name = cht_wc_leds_names[i];
led->cdev.brightness_set_blocking = cht_wc_leds_brightness_set;
led->cdev.brightness_get = cht_wc_leds_brightness_get;
led->cdev.blink_set = cht_wc_leds_blink_set;
led->cdev.pattern_set = cht_wc_leds_pattern_set;
led->cdev.pattern_clear = cht_wc_leds_pattern_clear;
led->cdev.max_brightness = 255;
ret = led_classdev_register(&pdev->dev, &led->cdev);
if (ret < 0)
return ret;
}
platform_set_drvdata(pdev, leds);
return 0;
}
static void cht_wc_leds_remove(struct platform_device *pdev)
{
struct cht_wc_leds *leds = platform_get_drvdata(pdev);
int i;
for (i = 0; i < CHT_WC_LED_COUNT; i++)
led_classdev_unregister(&leds->leds[i].cdev);
/* Restore LED1 regs if hw-control was active else leave LED1 off */
if (!(leds->led1_initial_regs.ctrl & CHT_WC_LED1_SWCTL))
cht_wc_led_restore_regs(&leds->leds[0], &leds->led1_initial_regs);
}
static void cht_wc_leds_disable(struct platform_device *pdev)
{
struct cht_wc_leds *leds = platform_get_drvdata(pdev);
int i;
for (i = 0; i < CHT_WC_LED_COUNT; i++)
cht_wc_leds_brightness_set(&leds->leds[i].cdev, 0);
/* Restore LED1 regs if hw-control was active else leave LED1 off */
if (!(leds->led1_initial_regs.ctrl & CHT_WC_LED1_SWCTL))
cht_wc_led_restore_regs(&leds->leds[0], &leds->led1_initial_regs);
}
/* On suspend save current settings and turn LEDs off */
static int cht_wc_leds_suspend(struct device *dev)
{
struct cht_wc_leds *leds = dev_get_drvdata(dev);
int i, ret;
for (i = 0; i < CHT_WC_LED_COUNT; i++) {
ret = cht_wc_led_save_regs(&leds->leds[i], &leds->leds[i].saved_regs);
if (ret < 0)
return ret;
}
cht_wc_leds_disable(to_platform_device(dev));
return 0;
}
/* On resume restore the saved settings */
static int cht_wc_leds_resume(struct device *dev)
{
struct cht_wc_leds *leds = dev_get_drvdata(dev);
int i;
for (i = 0; i < CHT_WC_LED_COUNT; i++)
cht_wc_led_restore_regs(&leds->leds[i], &leds->leds[i].saved_regs);
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(cht_wc_leds_pm, cht_wc_leds_suspend, cht_wc_leds_resume);
static struct platform_driver cht_wc_leds_driver = {
.probe = cht_wc_leds_probe,
.remove_new = cht_wc_leds_remove,
.shutdown = cht_wc_leds_disable,
.driver = {
.name = "cht_wcove_leds",
.pm = pm_sleep_ptr(&cht_wc_leds_pm),
},
};
module_platform_driver(cht_wc_leds_driver);
MODULE_ALIAS("platform:cht_wcove_leds");
MODULE_DESCRIPTION("Intel Cherry Trail Whiskey Cove PMIC LEDs driver");
MODULE_AUTHOR("Yauhen Kharuzhy <[email protected]>");
MODULE_LICENSE("GPL");
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