1 files changed, 476 insertions, 0 deletions

diff --git a/drivers/leds/leds-cht-wcove.c b/drivers/leds/leds-cht-wcove.c
new file mode 100644
index 0000000000..b4998402b8
--- /dev/null
+++ b/drivers/leds/leds-cht-wcove.c
@@ -0,0 +1,476 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for LEDs connected to the Intel Cherry Trail Whiskey Cove PMIC
+ *
+ * Copyright 2019 Yauhen Kharuzhy <jekhor@gmail.com>
+ * Copyright 2023 Hans de Goede <hansg@kernel.org>
+ *
+ * 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 <jekhor@gmail.com>");
+MODULE_LICENSE("GPL");