soc: qcom: Bring in qpnp-misc driver

qpnp-misc driver supports accessing MISC peripheral registers
in certain PMICs. Bring that in.

This snapshot is taken as of msm-4.4
'commit 9af69213de64 ("Merge "block: Move bdi_unregister() to
del_gendisk()"")'

Fixed a couple of minor issues to solve checkpatch errors.
 - Use const qualifier for qpnp_misc_match_table
 - Fixed a block comment

Also, moved the location of qpnp-misc.h from include/linux to
include/linux/qpnp.

Change-Id: Iad670e41cc9b95725cf0c651c835a782314f0015
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>
diff --git a/drivers/misc/qpnp-misc.c b/drivers/misc/qpnp-misc.c
new file mode 100644
index 0000000..3c11de0
--- /dev/null
+++ b/drivers/misc/qpnp-misc.c
@@ -0,0 +1,352 @@
+/* Copyright (c) 2013-2014,2016-2017, 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/module.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/qpnp/qpnp-misc.h>
+
+#define QPNP_MISC_DEV_NAME "qcom,qpnp-misc"
+
+#define REG_DIG_MAJOR_REV	0x01
+#define REG_SUBTYPE		0x05
+#define REG_PWM_SEL		0x49
+#define REG_GP_DRIVER_EN	0x4C
+
+#define PWM_SEL_MAX		0x03
+#define GP_DRIVER_EN_BIT	BIT(0)
+
+static DEFINE_MUTEX(qpnp_misc_dev_list_mutex);
+static LIST_HEAD(qpnp_misc_dev_list);
+
+struct qpnp_misc_version {
+	u8	subtype;
+	u8	dig_major_rev;
+};
+
+/**
+ * struct qpnp_misc_dev - holds controller device specific information
+ * @list:			Doubly-linked list parameter linking to other
+ *				qpnp_misc devices.
+ * @mutex:			Mutex lock that is used to ensure mutual
+ *				exclusion between probing and accessing misc
+ *				driver information
+ * @dev:			Device pointer to the misc device
+ * @regmap:			Regmap pointer to the misc device
+ * @version:			struct that holds the subtype and dig_major_rev
+ *				of the chip.
+ */
+struct qpnp_misc_dev {
+	struct list_head		list;
+	struct mutex			mutex;
+	struct device			*dev;
+	struct regmap			*regmap;
+	struct qpnp_misc_version	version;
+
+	u32				base;
+	u8				pwm_sel;
+	bool				enable_gp_driver;
+};
+
+static const struct of_device_id qpnp_misc_match_table[] = {
+	{ .compatible = QPNP_MISC_DEV_NAME },
+	{}
+};
+
+enum qpnp_misc_version_name {
+	INVALID,
+	PM8941,
+	PM8226,
+	PMA8084,
+	PMDCALIFORNIUM,
+};
+
+static struct qpnp_misc_version irq_support_version[] = {
+	{0x00, 0x00}, /* INVALID */
+	{0x01, 0x02}, /* PM8941 */
+	{0x07, 0x00}, /* PM8226 */
+	{0x09, 0x00}, /* PMA8084 */
+	{0x16, 0x00}, /* PMDCALIFORNIUM */
+};
+
+static int qpnp_write_byte(struct qpnp_misc_dev *mdev, u16 addr, u8 val)
+{
+	int rc;
+
+	rc = regmap_write(mdev->regmap, mdev->base + addr, val);
+	if (rc)
+		pr_err("regmap write failed rc=%d\n", rc);
+
+	return rc;
+}
+
+static int qpnp_read_byte(struct qpnp_misc_dev *mdev, u16 addr, u8 *val)
+{
+	unsigned int temp;
+	int rc;
+
+	rc = regmap_read(mdev->regmap, mdev->base + addr, &temp);
+	if (rc) {
+		pr_err("regmap read failed rc=%d\n", rc);
+		return rc;
+	}
+
+	*val = (u8)temp;
+	return rc;
+}
+
+static int get_qpnp_misc_version_name(struct qpnp_misc_dev *dev)
+{
+	int i;
+
+	for (i = 1; i < ARRAY_SIZE(irq_support_version); i++)
+		if (dev->version.subtype == irq_support_version[i].subtype &&
+		    dev->version.dig_major_rev >=
+					irq_support_version[i].dig_major_rev)
+			return i;
+
+	return INVALID;
+}
+
+static bool __misc_irqs_available(struct qpnp_misc_dev *dev)
+{
+	int version_name = get_qpnp_misc_version_name(dev);
+
+	if (version_name == INVALID)
+		return 0;
+	return 1;
+}
+
+int qpnp_misc_read_reg(struct device_node *node, u16 addr, u8 *val)
+{
+	struct qpnp_misc_dev *mdev = NULL;
+	struct qpnp_misc_dev *mdev_found = NULL;
+	int rc;
+	u8 temp;
+
+	if (IS_ERR_OR_NULL(node)) {
+		pr_err("Invalid device node pointer\n");
+		return -EINVAL;
+	}
+
+	mutex_lock(&qpnp_misc_dev_list_mutex);
+	list_for_each_entry(mdev, &qpnp_misc_dev_list, list) {
+		if (mdev->dev->of_node == node) {
+			mdev_found = mdev;
+			break;
+		}
+	}
+	mutex_unlock(&qpnp_misc_dev_list_mutex);
+
+	if (!mdev_found) {
+		/*
+		 * No MISC device was found. This API should only
+		 * be called by drivers which have specified the
+		 * misc phandle in their device tree node.
+		 */
+		pr_err("no probed misc device found\n");
+		return -EPROBE_DEFER;
+	}
+
+	rc = qpnp_read_byte(mdev, addr, &temp);
+	if (rc < 0) {
+		dev_err(mdev->dev, "Failed to read addr %x, rc=%d\n", addr, rc);
+		return rc;
+	}
+
+	*val = temp;
+	return 0;
+}
+
+int qpnp_misc_irqs_available(struct device *consumer_dev)
+{
+	struct device_node *misc_node = NULL;
+	struct qpnp_misc_dev *mdev = NULL;
+	struct qpnp_misc_dev *mdev_found = NULL;
+
+	if (IS_ERR_OR_NULL(consumer_dev)) {
+		pr_err("Invalid consumer device pointer\n");
+		return -EINVAL;
+	}
+
+	misc_node = of_parse_phandle(consumer_dev->of_node, "qcom,misc-ref", 0);
+	if (!misc_node) {
+		pr_debug("Could not find qcom,misc-ref property in %s\n",
+			consumer_dev->of_node->full_name);
+		return 0;
+	}
+
+	mutex_lock(&qpnp_misc_dev_list_mutex);
+	list_for_each_entry(mdev, &qpnp_misc_dev_list, list) {
+		if (mdev->dev->of_node == misc_node) {
+			mdev_found = mdev;
+			break;
+		}
+	}
+	mutex_unlock(&qpnp_misc_dev_list_mutex);
+
+	if (!mdev_found) {
+		/*
+		 * No MISC device was found. This API should only
+		 * be called by drivers which have specified the
+		 * misc phandle in their device tree node.
+		 */
+		pr_err("no probed misc device found\n");
+		return -EPROBE_DEFER;
+	}
+
+	return __misc_irqs_available(mdev_found);
+}
+
+static int qpnp_misc_dt_init(struct qpnp_misc_dev *mdev)
+{
+	struct device_node *node = mdev->dev->of_node;
+	u32 val;
+	int rc;
+
+	rc = of_property_read_u32(node, "reg", &mdev->base);
+	if (rc < 0 || !mdev->base) {
+		dev_err(mdev->dev, "Base address not defined or invalid\n");
+		return -EINVAL;
+	}
+
+	if (!of_property_read_u32(node, "qcom,pwm-sel", &val)) {
+		if (val > PWM_SEL_MAX) {
+			dev_err(mdev->dev, "Invalid value for pwm-sel\n");
+			return -EINVAL;
+		}
+		mdev->pwm_sel = (u8)val;
+	}
+	mdev->enable_gp_driver = of_property_read_bool(node,
+						"qcom,enable-gp-driver");
+
+	WARN((mdev->pwm_sel > 0 && !mdev->enable_gp_driver),
+			"Setting PWM source without enabling gp driver\n");
+	WARN((mdev->pwm_sel == 0 && mdev->enable_gp_driver),
+			"Enabling gp driver without setting PWM source\n");
+
+	return 0;
+}
+
+static int qpnp_misc_config(struct qpnp_misc_dev *mdev)
+{
+	int rc, version_name;
+
+	version_name = get_qpnp_misc_version_name(mdev);
+
+	switch (version_name) {
+	case PMDCALIFORNIUM:
+		if (mdev->pwm_sel > 0 && mdev->enable_gp_driver) {
+			rc = qpnp_write_byte(mdev, REG_PWM_SEL, mdev->pwm_sel);
+			if (rc < 0) {
+				dev_err(mdev->dev,
+					"Failed to write PWM_SEL reg\n");
+				return rc;
+			}
+
+			rc = qpnp_write_byte(mdev, REG_GP_DRIVER_EN,
+					GP_DRIVER_EN_BIT);
+			if (rc < 0) {
+				dev_err(mdev->dev,
+					"Failed to write GP_DRIVER_EN reg\n");
+				return rc;
+			}
+		}
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int qpnp_misc_probe(struct platform_device *pdev)
+{
+	struct qpnp_misc_dev *mdev = ERR_PTR(-EINVAL);
+	int rc;
+
+	mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
+	if (!mdev)
+		return -ENOMEM;
+
+	mdev->dev = &pdev->dev;
+	mdev->regmap = dev_get_regmap(mdev->dev->parent, NULL);
+	if (!mdev->regmap) {
+		dev_err(mdev->dev, "Parent regmap is unavailable\n");
+		return -ENXIO;
+	}
+
+	rc = qpnp_misc_dt_init(mdev);
+	if (rc < 0) {
+		dev_err(mdev->dev,
+			"Error reading device tree properties, rc=%d\n", rc);
+		return rc;
+	}
+
+
+	rc = qpnp_read_byte(mdev, REG_SUBTYPE, &mdev->version.subtype);
+	if (rc < 0) {
+		dev_err(mdev->dev, "Failed to read subtype, rc=%d\n", rc);
+		return rc;
+	}
+
+	rc = qpnp_read_byte(mdev, REG_DIG_MAJOR_REV,
+			&mdev->version.dig_major_rev);
+	if (rc < 0) {
+		dev_err(mdev->dev, "Failed to read dig_major_rev, rc=%d\n", rc);
+		return rc;
+	}
+
+	mutex_lock(&qpnp_misc_dev_list_mutex);
+	list_add_tail(&mdev->list, &qpnp_misc_dev_list);
+	mutex_unlock(&qpnp_misc_dev_list_mutex);
+
+	rc = qpnp_misc_config(mdev);
+	if (rc < 0) {
+		dev_err(mdev->dev,
+			"Error configuring module registers, rc=%d\n", rc);
+		return rc;
+	}
+
+	dev_info(mdev->dev, "probe successful\n");
+	return 0;
+}
+
+static struct platform_driver qpnp_misc_driver = {
+	.probe	= qpnp_misc_probe,
+	.driver	= {
+		.name		= QPNP_MISC_DEV_NAME,
+		.owner		= THIS_MODULE,
+		.of_match_table	= qpnp_misc_match_table,
+	},
+};
+
+static int __init qpnp_misc_init(void)
+{
+	return platform_driver_register(&qpnp_misc_driver);
+}
+
+static void __exit qpnp_misc_exit(void)
+{
+	return platform_driver_unregister(&qpnp_misc_driver);
+}
+
+subsys_initcall(qpnp_misc_init);
+module_exit(qpnp_misc_exit);
+
+MODULE_DESCRIPTION(QPNP_MISC_DEV_NAME);
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" QPNP_MISC_DEV_NAME);