leds: leds-qti-tri-led: Add LED driver for QTI TRI_LED module

QTI TRI_LED module has 3 current sinks at max for LED driver and
each is controlled by a PWM channel used for LED dimming or blinking.
Add the driver to support it.

Change-Id: Icac3ad7d18f13871c94e58156775267ed0c60fd9
Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>

Documentation/devicetree/bindings/leds/leds-qti-tri-led.txt

@@ -0,0 +1,60 @@
+Qualcomm Technologies, Inc. TRI_LED driver specific bindings
+
+This binding document describes the properties of TRI_LED module in
+Qualcomm Technologies, Inc. PMIC chips.
+
+- compatible:
+	Usage: required
+	Value type: <string>
+	Definition: Must be "qcom,tri-led".
+
+- reg:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: Register base of the TRI_LED module and length.
+
+Properties for child nodes:
+- pwms:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: The PWM device (phandle) used for controlling LED.
+
+- led-sources:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: see Documentation/devicetree/bindings/leds/common.txt;
+		Device current output identifiers are: 0 - LED1_EN,
+		1 - LED2_EN, 2 - LED3_EN.
+
+- label:
+	Usage: optional
+	Value type: <string>
+	Definition: see Documentation/devicetree/bindings/leds/common.txt;
+
+- linux,default-trigger:
+	Usage: optional
+	Value_type: <string>
+	Definition: see Documentation/devicetree/bindings/leds/common.txt;
+
+Example:
+
+	pmi8998_rgb: tri-led@d000{
+		compatible = "qcom,tri-led";
+		reg = <0xd000 0x100>;
+
+		red {
+			label = "red";
+			pwms = <&pmi8998_lpg 4 1000000>;
+			led-sources = <0>;
+		};
+		green {
+			label = "green";
+			pwms = <&pmi8998_lpg 3 1000000>;
+			led-sources = <1>;
+		};
+		blue {
+			label = "blue";
+			pwms = <&pmi8998_lpg 2 1000000>;
+			led-sources = <2>;
+		};
+	};

drivers/leds/Kconfig

@@ -662,6 +662,15 @@ config LEDS_POWERNV
 	  To compile this driver as a module, choose 'm' here: the module
 	  will be called leds-powernv.
 
+config LEDS_QTI_TRI_LED
+	tristate "LED support for Qualcomm Technologies, Inc. TRI_LED"
+	depends on LEDS_CLASS && MFD_SPMI_PMIC && PWM && OF
+	help
+	  This driver supports the TRI_LED module found in Qualcomm
+	  Technologies, Inc. PMIC chips. TRI_LED supports 3 LED drivers
+	  at max and each is controlled by a PWM channel used for dimming
+	  or blinking.
+
 config LEDS_SYSCON
 	bool "LED support for LEDs on system controllers"
 	depends on LEDS_CLASS=y

drivers/leds/Makefile

@@ -64,6 +64,7 @@ obj-$(CONFIG_LEDS_MAX77693)		+= leds-max77693.o
 obj-$(CONFIG_LEDS_MAX8997)		+= leds-max8997.o
 obj-$(CONFIG_LEDS_LM355x)		+= leds-lm355x.o
 obj-$(CONFIG_LEDS_BLINKM)		+= leds-blinkm.o
+obj-$(CONFIG_LEDS_QTI_TRI_LED)		+= leds-qti-tri-led.o
 obj-$(CONFIG_LEDS_SYSCON)		+= leds-syscon.o
 obj-$(CONFIG_LEDS_MENF21BMC)		+= leds-menf21bmc.o
 obj-$(CONFIG_LEDS_KTD2692)		+= leds-ktd2692.o

drivers/leds/leds-qti-tri-led.c

@@ -0,0 +1,512 @@
+/* Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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/bitops.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+#define TRILED_REG_TYPE			0x04
+#define TRILED_REG_SUBTYPE		0x05
+#define TRILED_REG_EN_CTL		0x46
+
+/* TRILED_REG_EN_CTL */
+#define TRILED_EN_CTL_MASK		GENMASK(7, 5)
+#define TRILED_EN_CTL_MAX_BIT		7
+
+#define TRILED_TYPE			0x19
+#define TRILED_SUBTYPE_LED3H0L12	0x02
+#define TRILED_SUBTYPE_LED2H0L12	0x03
+#define TRILED_SUBTYPE_LED1H2L12	0x04
+
+#define TRILED_NUM_MAX			3
+
+#define PWM_PERIOD_DEFAULT_NS		1000000
+#define LED_BLINK_ON_MS			125
+#define LED_BLINK_OFF_MS		875
+
+struct pwm_setting {
+	u32	pre_period_ns;
+	u32	period_ns;
+	u32	duty_ns;
+};
+
+struct led_setting {
+	u32			on_ms;
+	u32			off_ms;
+	enum led_brightness	brightness;
+	bool			blink;
+};
+
+struct qpnp_led_dev {
+	struct led_classdev	cdev;
+	struct pwm_device	*pwm_dev;
+	struct pwm_setting	pwm_setting;
+	struct led_setting	led_setting;
+	struct qpnp_tri_led_chip	*chip;
+	struct mutex		lock;
+	const char		*label;
+	const char		*default_trigger;
+	u8			id;
+	bool			blinking;
+};
+
+struct qpnp_tri_led_chip {
+	struct device		*dev;
+	struct regmap		*regmap;
+	struct qpnp_led_dev	*leds;
+	struct mutex		bus_lock;
+	int			num_leds;
+	u16			reg_base;
+	u8			subtype;
+};
+
+static int qpnp_tri_led_read(struct qpnp_tri_led_chip *chip, u16 addr, u8 *val)
+{
+	int rc;
+	unsigned int tmp;
+
+	mutex_lock(&chip->bus_lock);
+	rc = regmap_read(chip->regmap, chip->reg_base + addr, &tmp);
+	if (rc < 0)
+		dev_err(chip->dev, "Read addr 0x%x failed, rc=%d\n", addr, rc);
+	else
+		*val = (u8)tmp;
+	mutex_unlock(&chip->bus_lock);
+
+	return rc;
+}
+
+static int qpnp_tri_led_masked_write(struct qpnp_tri_led_chip *chip,
+				u16 addr, u8 mask, u8 val)
+{
+	int rc;
+
+	mutex_lock(&chip->bus_lock);
+	rc = regmap_update_bits(chip->regmap, chip->reg_base + addr, mask, val);
+	if (rc < 0)
+		dev_err(chip->dev, "Update addr 0x%x to val 0x%x with mask 0x%x failed, rc=%d\n",
+					addr, val, mask, rc);
+	mutex_unlock(&chip->bus_lock);
+
+	return rc;
+}
+
+static int __tri_led_config_pwm(struct qpnp_led_dev *led,
+				struct pwm_setting *pwm)
+{
+	struct pwm_state pstate;
+	int rc;
+
+	pwm_get_state(led->pwm_dev, &pstate);
+	pstate.enabled = !!(pwm->duty_ns != 0);
+	pstate.period = pwm->period_ns;
+	pstate.duty_cycle = pwm->duty_ns;
+	rc = pwm_apply_state(led->pwm_dev, &pstate);
+
+	if (rc < 0)
+		dev_err(led->chip->dev, "Apply PWM state for %s led failed, rc=%d\n",
+					led->cdev.name, rc);
+
+	return rc;
+}
+
+static int __tri_led_set(struct qpnp_led_dev *led)
+{
+	int rc = 0;
+	u8 val = 0, mask = 0;
+
+	rc = __tri_led_config_pwm(led, &led->pwm_setting);
+	if (rc < 0) {
+		dev_err(led->chip->dev, "Configure PWM for %s led failed, rc=%d\n",
+					led->cdev.name, rc);
+		return rc;
+	}
+
+	mask |= 1 << (TRILED_EN_CTL_MAX_BIT - led->id);
+
+	if (led->pwm_setting.duty_ns == 0)
+		val = 0;
+	else
+		val = mask;
+
+	rc = qpnp_tri_led_masked_write(led->chip, TRILED_REG_EN_CTL,
+							mask, val);
+	if (rc < 0)
+		dev_err(led->chip->dev, "Update addr 0x%x failed, rc=%d\n",
+					TRILED_REG_EN_CTL, rc);
+
+	return rc;
+}
+
+static int qpnp_tri_led_set(struct qpnp_led_dev *led)
+{
+	u32 on_ms, off_ms, period_ns, duty_ns;
+	enum led_brightness brightness = led->led_setting.brightness;
+	int rc = 0;
+
+	if (led->led_setting.blink) {
+		on_ms = led->led_setting.on_ms;
+		off_ms = led->led_setting.off_ms;
+		if (on_ms > INT_MAX / NSEC_PER_MSEC)
+			duty_ns = INT_MAX - 1;
+		else
+			duty_ns = on_ms * NSEC_PER_MSEC;
+
+		if (on_ms + off_ms > INT_MAX / NSEC_PER_MSEC) {
+			period_ns = INT_MAX;
+			duty_ns = (period_ns / (on_ms + off_ms)) * on_ms;
+		} else {
+			period_ns = (on_ms + off_ms) * NSEC_PER_MSEC;
+		}
+
+		if (period_ns < duty_ns && duty_ns != 0)
+			period_ns = duty_ns + 1;
+	} else {
+		/* Use initial period if no blinking is required */
+		period_ns = led->pwm_setting.pre_period_ns;
+
+		if (period_ns > INT_MAX / brightness)
+			duty_ns = (period_ns / LED_FULL) * brightness;
+		else
+			duty_ns = (period_ns * brightness) / LED_FULL;
+
+		if (period_ns < duty_ns && duty_ns != 0)
+			period_ns = duty_ns + 1;
+	}
+	dev_dbg(led->chip->dev, "PWM settings for %s led: period = %dns, duty = %dns\n",
+				led->cdev.name, period_ns, duty_ns);
+
+	led->pwm_setting.duty_ns = duty_ns;
+	led->pwm_setting.period_ns = period_ns;
+
+	rc = __tri_led_set(led);
+	if (rc < 0) {
+		dev_err(led->chip->dev, "__tri_led_set %s failed, rc=%d\n",
+				led->cdev.name, rc);
+		return rc;
+	}
+
+	if (led->led_setting.blink) {
+		led->cdev.brightness = LED_FULL;
+		led->blinking = true;
+	} else {
+		led->cdev.brightness = led->led_setting.brightness;
+		led->blinking = false;
+	}
+
+	return rc;
+}
+
+static int qpnp_tri_led_set_brightness(struct led_classdev *led_cdev,
+		enum led_brightness brightness)
+{
+	struct qpnp_led_dev *led =
+		container_of(led_cdev, struct qpnp_led_dev, cdev);
+	int rc = 0;
+
+	mutex_lock(&led->lock);
+	if (brightness > LED_FULL)
+		brightness = LED_FULL;
+
+	if (brightness == led->led_setting.brightness &&
+				!led->blinking) {
+		mutex_unlock(&led->lock);
+		return 0;
+	}
+
+	led->led_setting.brightness = brightness;
+	if (!!brightness)
+		led->led_setting.off_ms = 0;
+	else
+		led->led_setting.on_ms = 0;
+	led->led_setting.blink = false;
+
+	rc = qpnp_tri_led_set(led);
+	if (rc)
+		dev_err(led->chip->dev, "Set led failed for %s, rc=%d\n",
+				led->label, rc);
+
+	mutex_unlock(&led->lock);
+
+	return rc;
+}
+
+static enum led_brightness qpnp_tri_led_get_brightness(
+			struct led_classdev *led_cdev)
+{
+	return led_cdev->brightness;
+}
+
+static int qpnp_tri_led_set_blink(struct led_classdev *led_cdev,
+		unsigned long *on_ms, unsigned long *off_ms)
+{
+	struct qpnp_led_dev *led =
+		container_of(led_cdev, struct qpnp_led_dev, cdev);
+	int rc = 0;
+
+	mutex_lock(&led->lock);
+	if (led->blinking && *on_ms == led->led_setting.on_ms &&
+			*off_ms == led->led_setting.off_ms) {
+		dev_dbg(led_cdev->dev, "Ignore, on/off setting is not changed: on %lums, off %lums\n",
+						*on_ms, *off_ms);
+		mutex_unlock(&led->lock);
+		return 0;
+	}
+
+	if (*on_ms == 0) {
+		led->led_setting.blink = false;
+		led->led_setting.brightness = LED_OFF;
+	} else if (*off_ms == 0) {
+		led->led_setting.blink = false;
+		led->led_setting.brightness = led->cdev.brightness;
+	} else {
+		led->led_setting.on_ms = *on_ms;
+		led->led_setting.off_ms = *off_ms;
+		led->led_setting.blink = true;
+	}
+
+	rc = qpnp_tri_led_set(led);
+	if (rc)
+		dev_err(led->chip->dev, "Set led failed for %s, rc=%d\n",
+				led->label, rc);
+
+	mutex_unlock(&led->lock);
+	return rc;
+}
+
+static int qpnp_tri_led_register(struct qpnp_tri_led_chip *chip)
+{
+	struct qpnp_led_dev *led;
+	int rc, i, j;
+
+	for (i = 0; i < chip->num_leds; i++) {
+		led = &chip->leds[i];
+		mutex_init(&led->lock);
+		led->cdev.name = led->label;
+		led->cdev.max_brightness = LED_FULL;
+		led->cdev.brightness_set_blocking = qpnp_tri_led_set_brightness;
+		led->cdev.brightness_get = qpnp_tri_led_get_brightness;
+		led->cdev.blink_set = qpnp_tri_led_set_blink;
+		led->cdev.default_trigger = led->default_trigger;
+		led->cdev.brightness = LED_OFF;
+		led->cdev.blink_delay_on = LED_BLINK_ON_MS;
+		led->cdev.blink_delay_off = LED_BLINK_OFF_MS;
+
+		rc = devm_led_classdev_register(chip->dev, &led->cdev);
+		if (rc < 0) {
+			dev_err(chip->dev, "%s led class device registering failed, rc=%d\n",
+							led->label, rc);
+			goto destroy;
+		}
+	}
+
+	return 0;
+destroy:
+	for (j = 0; j <= i; j++)
+		mutex_destroy(&chip->leds[i].lock);
+
+	return rc;
+}
+
+static int qpnp_tri_led_hw_init(struct qpnp_tri_led_chip *chip)
+{
+	int rc = 0;
+	u8 val;
+
+	rc = qpnp_tri_led_read(chip, TRILED_REG_TYPE, &val);
+	if (rc < 0) {
+		dev_err(chip->dev, "Read REG_TYPE failed, rc=%d\n", rc);
+		return rc;
+	}
+
+	if (val != TRILED_TYPE) {
+		dev_err(chip->dev, "invalid subtype(%d)\n", val);
+		return -ENODEV;
+	}
+
+	rc = qpnp_tri_led_read(chip, TRILED_REG_SUBTYPE, &val);
+	if (rc < 0) {
+		dev_err(chip->dev, "Read REG_SUBTYPE failed, rc=%d\n", rc);
+		return rc;
+	}
+
+	chip->subtype = val;
+
+	return 0;
+}
+
+static int qpnp_tri_led_parse_dt(struct qpnp_tri_led_chip *chip)
+{
+	struct device_node *node = chip->dev->of_node, *child_node;
+	struct qpnp_led_dev *led;
+	struct pwm_args pargs;
+	const __be32 *addr;
+	int rc, id, i = 0;
+
+	addr = of_get_address(chip->dev->of_node, 0, NULL, NULL);
+	if (!addr) {
+		dev_err(chip->dev, "Getting address failed\n");
+		return -EINVAL;
+	}
+	chip->reg_base = be32_to_cpu(addr[0]);
+
+	chip->num_leds = of_get_available_child_count(node);
+	if (chip->num_leds == 0) {
+		dev_err(chip->dev, "No led child node defined\n");
+		return -ENODEV;
+	}
+
+	if (chip->num_leds > TRILED_NUM_MAX) {
+		dev_err(chip->dev, "can't support %d leds(max %d)\n",
+				chip->num_leds, TRILED_NUM_MAX);
+		return -EINVAL;
+	}
+
+	chip->leds = devm_kcalloc(chip->dev, chip->num_leds,
+			sizeof(struct qpnp_led_dev), GFP_KERNEL);
+	if (!chip->leds)
+		return -ENOMEM;
+
+	for_each_available_child_of_node(node, child_node) {
+		rc = of_property_read_u32(child_node, "led-sources", &id);
+		if (rc) {
+			dev_err(chip->dev, "Get led-sources failed, rc=%d\n",
+							rc);
+			return rc;
+		}
+
+		if (id >= TRILED_NUM_MAX) {
+			dev_err(chip->dev, "only support 0~%d current source\n",
+					TRILED_NUM_MAX - 1);
+			return -EINVAL;
+		}
+
+		led = &chip->leds[i++];
+		led->chip = chip;
+		led->id = id;
+		led->label =
+			of_get_property(child_node, "label", NULL) ? :
+							child_node->name;
+
+		led->pwm_dev =
+			devm_of_pwm_get(chip->dev, child_node, NULL);
+		if (IS_ERR(led->pwm_dev)) {
+			rc = PTR_ERR(led->pwm_dev);
+			if (rc != -EPROBE_DEFER)
+				dev_err(chip->dev, "Get pwm device for %s led failed, rc=%d\n",
+							led->label, rc);
+			return rc;
+		}
+
+		pwm_get_args(led->pwm_dev, &pargs);
+		if (pargs.period == 0)
+			led->pwm_setting.pre_period_ns = PWM_PERIOD_DEFAULT_NS;
+		else
+			led->pwm_setting.pre_period_ns = pargs.period;
+
+		led->default_trigger = of_get_property(child_node,
+				"linux,default-trigger", NULL);
+	}
+
+	return rc;
+}
+
+static int qpnp_tri_led_probe(struct platform_device *pdev)
+{
+	struct qpnp_tri_led_chip *chip;
+	int rc = 0;
+
+	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->dev = &pdev->dev;
+	chip->regmap = dev_get_regmap(chip->dev->parent, NULL);
+	if (!chip->regmap) {
+		dev_err(chip->dev, "Getting regmap failed\n");
+		return -EINVAL;
+	}
+
+	rc = qpnp_tri_led_parse_dt(chip);
+	if (rc < 0) {
+		dev_err(chip->dev, "Devicetree properties parsing failed, rc=%d\n",
+								rc);
+		return rc;
+	}
+
+	mutex_init(&chip->bus_lock);
+
+	rc = qpnp_tri_led_hw_init(chip);
+	if (rc) {
+		dev_err(chip->dev, "HW initialization failed, rc=%d\n", rc);
+		goto destroy;
+	}
+
+	dev_set_drvdata(chip->dev, chip);
+	rc = qpnp_tri_led_register(chip);
+	if (rc < 0) {
+		dev_err(chip->dev, "Registering LED class devices failed, rc=%d\n",
+								rc);
+		goto destroy;
+	}
+
+	dev_dbg(chip->dev, "Tri-led module with subtype 0x%x is detected\n",
+					chip->subtype);
+	return 0;
+destroy:
+	mutex_destroy(&chip->bus_lock);
+	dev_set_drvdata(chip->dev, NULL);
+
+	return rc;
+}
+
+static int qpnp_tri_led_remove(struct platform_device *pdev)
+{
+	int i;
+	struct qpnp_tri_led_chip *chip = dev_get_drvdata(&pdev->dev);
+
+	mutex_destroy(&chip->bus_lock);
+	for (i = 0; i < chip->num_leds; i++)
+		mutex_destroy(&chip->leds[i].lock);
+	dev_set_drvdata(chip->dev, NULL);
+	return 0;
+}
+
+static const struct of_device_id qpnp_tri_led_of_match[] = {
+	{ .compatible = "qcom,tri-led",},
+	{ },
+};
+
+static struct platform_driver qpnp_tri_led_driver = {
+	.driver		= {
+		.name		= "qcom,tri-led",
+		.of_match_table	= qpnp_tri_led_of_match,
+	},
+	.probe		= qpnp_tri_led_probe,
+	.remove		= qpnp_tri_led_remove,
+};
+module_platform_driver(qpnp_tri_led_driver);
+
+MODULE_DESCRIPTION("QTI TRI_LED driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("leds:qpnp-tri-led");