leds: qpnp: add driver file for configuring Vibrator LDO

Add a platform driver for configuring QPNP Vibrator LDO
HW module. The driver registers to leds framework and
exposes device attributes such as state, duration, activate
and vmax_uv.

CRs-Fixed: 2165526
Change-Id: Ib18fb4bdb6e412e7ef8b094501e0e0f8c89a2077
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>
diff --git a/drivers/leds/leds-qpnp-vibrator-ldo.c b/drivers/leds/leds-qpnp-vibrator-ldo.c
new file mode 100644
index 0000000..6a14324
--- /dev/null
+++ b/drivers/leds/leds-qpnp-vibrator-ldo.c
@@ -0,0 +1,550 @@
+/* Copyright (c) 2017-2018, 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.
+ */
+
+#define pr_fmt(fmt)	"%s: " fmt, __func__
+
+#include <linux/errno.h>
+#include <linux/hrtimer.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/workqueue.h>
+
+/* Vibrator-LDO register definitions */
+#define QPNP_VIB_LDO_REG_STATUS1	0x08
+#define QPNP_VIB_LDO_VREG_READY		BIT(7)
+
+#define QPNP_VIB_LDO_REG_VSET_LB	0x40
+
+#define QPNP_VIB_LDO_REG_EN_CTL		0x46
+#define QPNP_VIB_LDO_EN			BIT(7)
+
+/* Vibrator-LDO voltage settings */
+#define QPNP_VIB_LDO_VMIN_UV		1504000
+#define QPNP_VIB_LDO_VMAX_UV		3544000
+#define QPNP_VIB_LDO_VOLT_STEP_UV	8000
+
+/*
+ * Define vibration periods: default(5sec), min(50ms), max(15sec) and
+ * overdrive(30ms).
+ */
+#define QPNP_VIB_MIN_PLAY_MS		50
+#define QPNP_VIB_PLAY_MS		5000
+#define QPNP_VIB_MAX_PLAY_MS		15000
+#define QPNP_VIB_OVERDRIVE_PLAY_MS	30
+
+struct vib_ldo_chip {
+	struct led_classdev	cdev;
+	struct regmap		*regmap;
+	struct mutex		lock;
+	struct hrtimer		stop_timer;
+	struct hrtimer		overdrive_timer;
+	struct work_struct	vib_work;
+	struct work_struct	overdrive_work;
+
+	u16			base;
+	int			vmax_uV;
+	int			overdrive_volt_uV;
+	int			ldo_uV;
+	int			state;
+	u64			vib_play_ms;
+	bool			vib_enabled;
+	bool			disable_overdrive;
+};
+
+static int qpnp_vib_ldo_set_voltage(struct vib_ldo_chip *chip, int new_uV)
+{
+	unsigned int val;
+	u32 vlevel;
+	u8 reg[2];
+	int ret;
+
+	if (chip->ldo_uV == new_uV)
+		return 0;
+
+	vlevel = roundup(new_uV, QPNP_VIB_LDO_VOLT_STEP_UV) / 1000;
+	reg[0] = vlevel & 0xff;
+	reg[1] = (vlevel & 0xff00) >> 8;
+	ret = regmap_bulk_write(chip->regmap,
+				chip->base + QPNP_VIB_LDO_REG_VSET_LB, reg, 2);
+	if (ret < 0) {
+		pr_err("regmap write failed, ret=%d\n", ret);
+		return ret;
+	}
+
+	if (chip->vib_enabled) {
+		ret = regmap_read_poll_timeout(chip->regmap,
+					chip->base + QPNP_VIB_LDO_REG_STATUS1,
+					val, val & QPNP_VIB_LDO_VREG_READY,
+					100, 1000);
+		if (ret < 0) {
+			pr_err("Vibrator LDO vreg_ready timeout, status=0x%02x, ret=%d\n",
+				val, ret);
+			return ret;
+		}
+	}
+
+	chip->ldo_uV = new_uV;
+	return ret;
+}
+
+static inline int qpnp_vib_ldo_enable(struct vib_ldo_chip *chip, bool enable)
+{
+	unsigned int val;
+	int ret;
+
+	if (chip->vib_enabled == enable)
+		return 0;
+
+	ret = regmap_update_bits(chip->regmap,
+				chip->base + QPNP_VIB_LDO_REG_EN_CTL,
+				QPNP_VIB_LDO_EN,
+				enable ? QPNP_VIB_LDO_EN : 0);
+	if (ret < 0) {
+		pr_err("Program Vibrator LDO %s is failed, ret=%d\n",
+			enable ? "enable" : "disable", ret);
+		return ret;
+	}
+
+	if (enable) {
+		ret = regmap_read_poll_timeout(chip->regmap,
+					chip->base + QPNP_VIB_LDO_REG_STATUS1,
+					val, val & QPNP_VIB_LDO_VREG_READY,
+					100, 1000);
+		if (ret < 0) {
+			pr_err("Vibrator LDO vreg_ready timeout, status=0x%02x, ret=%d\n",
+				val, ret);
+			return ret;
+		}
+	}
+
+	chip->vib_enabled = enable;
+
+	return ret;
+}
+
+static int qpnp_vibrator_play_on(struct vib_ldo_chip *chip)
+{
+	int volt_uV;
+	int ret;
+
+	volt_uV = chip->vmax_uV;
+	if (!chip->disable_overdrive)
+		volt_uV = chip->overdrive_volt_uV ? chip->overdrive_volt_uV
+				: min(chip->vmax_uV * 2, QPNP_VIB_LDO_VMAX_UV);
+
+	ret = qpnp_vib_ldo_set_voltage(chip, volt_uV);
+	if (ret < 0) {
+		pr_err("set voltage = %duV failed, ret=%d\n", volt_uV, ret);
+		return ret;
+	}
+	pr_debug("voltage set to %d uV\n", volt_uV);
+
+	ret = qpnp_vib_ldo_enable(chip, true);
+	if (ret < 0) {
+		pr_err("vibration enable failed, ret=%d\n", ret);
+		return ret;
+	}
+
+	if (!chip->disable_overdrive)
+		hrtimer_start(&chip->overdrive_timer,
+			ms_to_ktime(QPNP_VIB_OVERDRIVE_PLAY_MS),
+			HRTIMER_MODE_REL);
+
+	return ret;
+}
+
+static void qpnp_vib_work(struct work_struct *work)
+{
+	struct vib_ldo_chip *chip = container_of(work, struct vib_ldo_chip,
+						vib_work);
+	int ret = 0;
+
+	if (chip->state) {
+		if (!chip->vib_enabled)
+			ret = qpnp_vibrator_play_on(chip);
+
+		if (ret == 0)
+			hrtimer_start(&chip->stop_timer,
+				      ms_to_ktime(chip->vib_play_ms),
+				      HRTIMER_MODE_REL);
+	} else {
+		if (!chip->disable_overdrive) {
+			hrtimer_cancel(&chip->overdrive_timer);
+			cancel_work_sync(&chip->overdrive_work);
+		}
+		qpnp_vib_ldo_enable(chip, false);
+	}
+}
+
+static enum hrtimer_restart vib_stop_timer(struct hrtimer *timer)
+{
+	struct vib_ldo_chip *chip = container_of(timer, struct vib_ldo_chip,
+					     stop_timer);
+
+	chip->state = 0;
+	schedule_work(&chip->vib_work);
+	return HRTIMER_NORESTART;
+}
+
+static void qpnp_vib_overdrive_work(struct work_struct *work)
+{
+	struct vib_ldo_chip *chip = container_of(work, struct vib_ldo_chip,
+					     overdrive_work);
+	int ret;
+
+	mutex_lock(&chip->lock);
+
+	/* LDO voltage update not required if Vibration disabled */
+	if (!chip->vib_enabled)
+		goto unlock;
+
+	ret = qpnp_vib_ldo_set_voltage(chip, chip->vmax_uV);
+	if (ret < 0) {
+		pr_err("set vibration voltage = %duV failed, ret=%d\n",
+			chip->vmax_uV, ret);
+		qpnp_vib_ldo_enable(chip, false);
+		goto unlock;
+	}
+	pr_debug("voltage set to %d\n", chip->vmax_uV);
+
+unlock:
+	mutex_unlock(&chip->lock);
+}
+
+static enum hrtimer_restart vib_overdrive_timer(struct hrtimer *timer)
+{
+	struct vib_ldo_chip *chip = container_of(timer, struct vib_ldo_chip,
+					     overdrive_timer);
+	schedule_work(&chip->overdrive_work);
+	pr_debug("overdrive timer expired\n");
+	return HRTIMER_NORESTART;
+}
+
+static ssize_t qpnp_vib_show_state(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *cdev = dev_get_drvdata(dev);
+	struct vib_ldo_chip *chip = container_of(cdev, struct vib_ldo_chip,
+						cdev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", chip->vib_enabled);
+}
+
+static ssize_t qpnp_vib_store_state(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	/* At present, nothing to do with setting state */
+	return count;
+}
+
+static ssize_t qpnp_vib_show_duration(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *cdev = dev_get_drvdata(dev);
+	struct vib_ldo_chip *chip = container_of(cdev, struct vib_ldo_chip,
+						cdev);
+	ktime_t time_rem;
+	s64 time_ms = 0;
+
+	if (hrtimer_active(&chip->stop_timer)) {
+		time_rem = hrtimer_get_remaining(&chip->stop_timer);
+		time_ms = ktime_to_ms(time_rem);
+	}
+
+	return snprintf(buf, PAGE_SIZE, "%lld\n", time_ms);
+}
+
+static ssize_t qpnp_vib_store_duration(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct led_classdev *cdev = dev_get_drvdata(dev);
+	struct vib_ldo_chip *chip = container_of(cdev, struct vib_ldo_chip,
+						cdev);
+	u32 val;
+	int ret;
+
+	ret = kstrtouint(buf, 0, &val);
+	if (ret < 0)
+		return ret;
+
+	/* setting 0 on duration is NOP for now */
+	if (val <= 0)
+		return count;
+
+	if (val < QPNP_VIB_MIN_PLAY_MS)
+		val = QPNP_VIB_MIN_PLAY_MS;
+
+	if (val > QPNP_VIB_MAX_PLAY_MS)
+		val = QPNP_VIB_MAX_PLAY_MS;
+
+	mutex_lock(&chip->lock);
+	chip->vib_play_ms = val;
+	mutex_unlock(&chip->lock);
+
+	return count;
+}
+
+static ssize_t qpnp_vib_show_activate(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	/* For now nothing to show */
+	return snprintf(buf, PAGE_SIZE, "%d\n", 0);
+}
+
+static ssize_t qpnp_vib_store_activate(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct led_classdev *cdev = dev_get_drvdata(dev);
+	struct vib_ldo_chip *chip = container_of(cdev, struct vib_ldo_chip,
+						cdev);
+	u32 val;
+	int ret;
+
+	ret = kstrtouint(buf, 0, &val);
+	if (ret < 0)
+		return ret;
+
+	if (val != 0 && val != 1)
+		return count;
+
+	mutex_lock(&chip->lock);
+	hrtimer_cancel(&chip->stop_timer);
+	chip->state = val;
+	pr_debug("state = %d, time = %llums\n", chip->state, chip->vib_play_ms);
+	mutex_unlock(&chip->lock);
+	schedule_work(&chip->vib_work);
+
+	return count;
+}
+
+static ssize_t qpnp_vib_show_vmax(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *cdev = dev_get_drvdata(dev);
+	struct vib_ldo_chip *chip = container_of(cdev, struct vib_ldo_chip,
+						cdev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", chip->vmax_uV / 1000);
+}
+
+static ssize_t qpnp_vib_store_vmax(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct led_classdev *cdev = dev_get_drvdata(dev);
+	struct vib_ldo_chip *chip = container_of(cdev, struct vib_ldo_chip,
+						cdev);
+	int data, ret;
+
+	ret = kstrtoint(buf, 10, &data);
+	if (ret < 0)
+		return ret;
+
+	data = data * 1000; /* Convert to microvolts */
+
+	/* check against vibrator ldo min/max voltage limits */
+	data = min(data, QPNP_VIB_LDO_VMAX_UV);
+	data = max(data, QPNP_VIB_LDO_VMIN_UV);
+
+	mutex_lock(&chip->lock);
+	chip->vmax_uV = data;
+	mutex_unlock(&chip->lock);
+	return ret;
+}
+
+static struct device_attribute qpnp_vib_attrs[] = {
+	__ATTR(state, 0664, qpnp_vib_show_state, qpnp_vib_store_state),
+	__ATTR(duration, 0664, qpnp_vib_show_duration, qpnp_vib_store_duration),
+	__ATTR(activate, 0664, qpnp_vib_show_activate, qpnp_vib_store_activate),
+	__ATTR(vmax_mv, 0664, qpnp_vib_show_vmax, qpnp_vib_store_vmax),
+};
+
+static int qpnp_vib_parse_dt(struct device *dev, struct vib_ldo_chip *chip)
+{
+	int ret;
+
+	ret = of_property_read_u32(dev->of_node, "qcom,vib-ldo-volt-uv",
+				&chip->vmax_uV);
+	if (ret < 0) {
+		pr_err("qcom,vib-ldo-volt-uv property read failed, ret=%d\n",
+			ret);
+		return ret;
+	}
+
+	chip->disable_overdrive = of_property_read_bool(dev->of_node,
+					"qcom,disable-overdrive");
+
+	if (of_find_property(dev->of_node, "qcom,vib-overdrive-volt-uv",
+			     NULL)) {
+		ret = of_property_read_u32(dev->of_node,
+					   "qcom,vib-overdrive-volt-uv",
+					   &chip->overdrive_volt_uV);
+		if (ret < 0) {
+			pr_err("qcom,vib-overdrive-volt-uv property read failed, ret=%d\n",
+				ret);
+			return ret;
+		}
+
+		/* check against vibrator ldo min/max voltage limits */
+		chip->overdrive_volt_uV = min(chip->overdrive_volt_uV,
+						QPNP_VIB_LDO_VMAX_UV);
+		chip->overdrive_volt_uV = max(chip->overdrive_volt_uV,
+						QPNP_VIB_LDO_VMIN_UV);
+	}
+
+	return ret;
+}
+
+/* Dummy functions for brightness */
+static enum led_brightness qpnp_vib_brightness_get(struct led_classdev *cdev)
+{
+	return 0;
+}
+
+static void qpnp_vib_brightness_set(struct led_classdev *cdev,
+			enum led_brightness level)
+{
+}
+
+static int qpnp_vibrator_ldo_suspend(struct device *dev)
+{
+	struct vib_ldo_chip *chip = dev_get_drvdata(dev);
+
+	mutex_lock(&chip->lock);
+	if (!chip->disable_overdrive) {
+		hrtimer_cancel(&chip->overdrive_timer);
+		cancel_work_sync(&chip->overdrive_work);
+	}
+	hrtimer_cancel(&chip->stop_timer);
+	cancel_work_sync(&chip->vib_work);
+	mutex_unlock(&chip->lock);
+
+	return 0;
+}
+static SIMPLE_DEV_PM_OPS(qpnp_vibrator_ldo_pm_ops, qpnp_vibrator_ldo_suspend,
+			NULL);
+
+static int qpnp_vibrator_ldo_probe(struct platform_device *pdev)
+{
+	struct device_node *of_node = pdev->dev.of_node;
+	struct vib_ldo_chip *chip;
+	int i, ret;
+	u32 base;
+
+	ret = of_property_read_u32(of_node, "reg", &base);
+	if (ret < 0) {
+		pr_err("reg property reading failed, ret=%d\n", ret);
+		return ret;
+	}
+
+	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!chip->regmap) {
+		pr_err("couldn't get parent's regmap\n");
+		return -EINVAL;
+	}
+
+	ret = qpnp_vib_parse_dt(&pdev->dev, chip);
+	if (ret < 0) {
+		pr_err("couldn't parse device tree, ret=%d\n", ret);
+		return ret;
+	}
+
+	chip->base = (uint16_t)base;
+	chip->vib_play_ms = QPNP_VIB_PLAY_MS;
+	mutex_init(&chip->lock);
+	INIT_WORK(&chip->vib_work, qpnp_vib_work);
+	INIT_WORK(&chip->overdrive_work, qpnp_vib_overdrive_work);
+
+	hrtimer_init(&chip->stop_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	chip->stop_timer.function = vib_stop_timer;
+	hrtimer_init(&chip->overdrive_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	chip->overdrive_timer.function = vib_overdrive_timer;
+	dev_set_drvdata(&pdev->dev, chip);
+
+	chip->cdev.name = "vibrator";
+	chip->cdev.brightness_get = qpnp_vib_brightness_get;
+	chip->cdev.brightness_set = qpnp_vib_brightness_set;
+	chip->cdev.max_brightness = 100;
+	ret = devm_led_classdev_register(&pdev->dev, &chip->cdev);
+	if (ret < 0) {
+		pr_err("Error in registering led class device, ret=%d\n", ret);
+		goto fail;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(qpnp_vib_attrs); i++) {
+		ret = sysfs_create_file(&chip->cdev.dev->kobj,
+				&qpnp_vib_attrs[i].attr);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "Error in creating sysfs file, ret=%d\n",
+				ret);
+			goto sysfs_fail;
+		}
+	}
+
+	pr_info("Vibrator LDO successfully registered: uV = %d, overdrive = %s\n",
+		chip->vmax_uV,
+		chip->disable_overdrive ? "disabled" : "enabled");
+	return 0;
+
+sysfs_fail:
+	for (--i; i >= 0; i--)
+		sysfs_remove_file(&chip->cdev.dev->kobj,
+				&qpnp_vib_attrs[i].attr);
+fail:
+	mutex_destroy(&chip->lock);
+	dev_set_drvdata(&pdev->dev, NULL);
+	return ret;
+}
+
+static int qpnp_vibrator_ldo_remove(struct platform_device *pdev)
+{
+	struct vib_ldo_chip *chip = dev_get_drvdata(&pdev->dev);
+
+	if (!chip->disable_overdrive) {
+		hrtimer_cancel(&chip->overdrive_timer);
+		cancel_work_sync(&chip->overdrive_work);
+	}
+	hrtimer_cancel(&chip->stop_timer);
+	cancel_work_sync(&chip->vib_work);
+	mutex_destroy(&chip->lock);
+	dev_set_drvdata(&pdev->dev, NULL);
+
+	return 0;
+}
+
+static const struct of_device_id vibrator_ldo_match_table[] = {
+	{ .compatible = "qcom,qpnp-vibrator-ldo" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, vibrator_ldo_match_table);
+
+static struct platform_driver qpnp_vibrator_ldo_driver = {
+	.driver	= {
+		.name		= "qcom,qpnp-vibrator-ldo",
+		.of_match_table	= vibrator_ldo_match_table,
+		.pm		= &qpnp_vibrator_ldo_pm_ops,
+	},
+	.probe	= qpnp_vibrator_ldo_probe,
+	.remove	= qpnp_vibrator_ldo_remove,
+};
+module_platform_driver(qpnp_vibrator_ldo_driver);
+
+MODULE_DESCRIPTION("QCOM QPNP Vibrator-LDO driver");
+MODULE_LICENSE("GPL v2");