[PATCH 2/2] qcom: ipq4019: Add LDO regulator driver for SDHC controller

[Sreedhar Sambangi]

From: Kirthik Srinivasan <kirthik@xxxxxxxxxxxxxx>

Add LDO regulator driver to enable SD /MMC  card to
switch between 3.0 volts and 1.8 volts

Change-Id: I66f770878570b1f5b1db044ba626e0f6989acc3f
Signed-off-by: Kirthik Srinivasan <kirthik@xxxxxxxxxxxxxx>
Signed-off-by: Rajith Cherian <rajith@xxxxxxxxxxxxxx>
Signed-off-by: Sreedhar Sambangi <ssambang@xxxxxxxxxxxxxx>
---
 drivers/regulator/Kconfig             |   7 +
 drivers/regulator/Makefile            |   1 +
 drivers/regulator/ipq4019-regulator.c | 275 ++++++++++++++++++++++++++++++++++
 3 files changed, 283 insertions(+)
 create mode 100644 drivers/regulator/ipq4019-regulator.c

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index c77dc08..bb44873 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -843,5 +843,12 @@ config REGULATOR_WM8994
 	  This driver provides support for the voltage regulators on the
 	  WM8994 CODEC.
 
+config REGULATOR_IPQ4019
+	tristate "IPQ4019 regulator support"
+	depends on ARCH_QCOM
+	help
+	  This driver provides support for the voltage regulators of the
+	  IPQ40xx devices.
+
 endif
 
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 61bfbb9..3647e8e 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -108,6 +108,7 @@ obj-$(CONFIG_REGULATOR_WM831X) += wm831x-ldo.o
 obj-$(CONFIG_REGULATOR_WM8350) += wm8350-regulator.o
 obj-$(CONFIG_REGULATOR_WM8400) += wm8400-regulator.o
 obj-$(CONFIG_REGULATOR_WM8994) += wm8994-regulator.o
+obj-$(CONFIG_REGULATOR_IPQ4019) += ipq4019-regulator.o
 
 
 ccflags-$(CONFIG_REGULATOR_DEBUG) += -DDEBUG
diff --git a/drivers/regulator/ipq4019-regulator.c b/drivers/regulator/ipq4019-regulator.c
new file mode 100644
index 0000000..c4903aa
--- /dev/null
+++ b/drivers/regulator/ipq4019-regulator.c
@@ -0,0 +1,275 @@
+/* Copyright (c) 2015, The Linux Foundation. All rights reserved.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/io.h>
+
+struct ipq4019_regulator_state {
+	int range;
+	int value;
+};
+
+struct ipq4019_regulator_config {
+	const char *supply_name;
+	struct ipq4019_regulator_state *states;
+	int nr_states;
+	int mask;
+	enum regulator_type type;
+	struct regulator_init_data *init_data;
+	void __iomem *base;
+};
+
+struct ipq4019_regulator_data {
+	struct regulator_desc desc;
+	struct regulator_dev *dev;
+	struct ipq4019_regulator_config *config;
+	int range;
+};
+
+static int ipq4019_regulator_get_voltage(struct regulator_dev *dev)
+{
+	struct ipq4019_regulator_data *data = rdev_get_drvdata(dev);
+	struct ipq4019_regulator_config *cfg = data->config;
+	int ptr;
+
+	for (ptr = 0; ptr < cfg->nr_states; ptr++)
+		if (cfg->states[ptr].range == data->range)
+			return cfg->states[ptr].range;
+
+	return -EINVAL;
+}
+
+static int ipq4019_regulator_set_voltage(struct regulator_dev *dev,
+					int min_uV, int max_uV,
+					unsigned *selector)
+{
+	struct ipq4019_regulator_data *data = rdev_get_drvdata(dev);
+	struct ipq4019_regulator_config *cfg = data->config;
+
+	int ptr, best_val = INT_MAX, val;
+
+	for (ptr = 0; ptr < cfg->nr_states; ptr++)
+		if (cfg->states[ptr].range < best_val &&
+		    cfg->states[ptr].range >= min_uV &&
+		    cfg->states[ptr].range <= max_uV) {
+			best_val = cfg->states[ptr].value;
+			if (selector)
+				*selector = ptr;
+		}
+
+	if (best_val == INT_MAX)
+		return -EINVAL;
+
+	val = readl(cfg->base);
+	val  = val & (~(cfg->mask));
+	writel((val | best_val), cfg->base);
+
+	data->range = cfg->states[ptr].range;
+
+	return 0;
+}
+
+static int ipq4019_regulator_list_voltage(struct regulator_dev *dev,
+				      unsigned selector)
+{
+	struct ipq4019_regulator_data *data = rdev_get_drvdata(dev);
+	struct ipq4019_regulator_config *cfg = data->config;
+
+	if (selector >= cfg->nr_states)
+		return -EINVAL;
+
+	return cfg->states[selector].range;
+}
+
+static struct regulator_ops ipq4019_regulator_voltage_ops = {
+	.get_voltage = ipq4019_regulator_get_voltage,
+	.set_voltage = ipq4019_regulator_set_voltage,
+	.list_voltage = ipq4019_regulator_list_voltage,
+};
+
+static struct ipq4019_regulator_config *
+of_get_ipq4019_regulator_data(struct device *dev, struct device_node *np, const struct regulator_desc *desc)
+{
+	struct ipq4019_regulator_config *config;
+	struct property *prop;
+	int proplen, i;
+
+	config = devm_kzalloc(dev,
+			sizeof(struct ipq4019_regulator_config),
+			GFP_KERNEL);
+	if (!config)
+		return ERR_PTR(-ENOMEM);
+
+	config->init_data = of_get_regulator_init_data(dev, np, desc);
+	if (!config->init_data)
+		return ERR_PTR(-EINVAL);
+
+	config->supply_name = config->init_data->constraints.name;
+
+
+	/* Fetch states. */
+	prop = of_find_property(np, "states", NULL);
+	if (!prop) {
+		dev_err(dev, "No 'states' property found\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	proplen = prop->length / sizeof(int);
+
+	config->states = devm_kzalloc(dev,
+				sizeof(struct ipq4019_regulator_state)
+				* (proplen / 2),
+				GFP_KERNEL);
+	if (!config->states)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < proplen / 2; i++) {
+		config->states[i].range =
+			be32_to_cpup((int *)prop->value + (i * 2));
+		config->states[i].value =
+			be32_to_cpup((int *)prop->value + (i * 2 + 1));
+	}
+	config->nr_states = i;
+
+	prop = of_find_property(np, "mask", NULL);
+	if (!prop) {
+		dev_err(dev, "No 'states' property found\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	config->mask = be32_to_cpup((int *)prop->value);
+	config->type = REGULATOR_VOLTAGE;
+
+	return config;
+}
+
+static int ipq4019_regulator_probe(struct platform_device *pdev)
+{
+	struct ipq4019_regulator_config *config = dev_get_platdata(&pdev->dev);
+	struct device_node *np = pdev->dev.of_node;
+	struct ipq4019_regulator_data *drvdata;
+	struct regulator_config cfg = { };
+	int ret;
+	struct resource *res;
+
+	drvdata = devm_kzalloc(&pdev->dev,
+				sizeof(struct ipq4019_regulator_data),
+				GFP_KERNEL);
+	if (drvdata == NULL) {
+		dev_err(&pdev->dev, "Failed to allocate device data\n");
+		return -ENOMEM;
+	}
+
+	if (np) {
+		config = of_get_ipq4019_regulator_data(&pdev->dev, np, &drvdata->desc);
+		if (IS_ERR(config))
+			return PTR_ERR(config);
+	}
+
+	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
+	if (drvdata->desc.name == NULL) {
+		dev_err(&pdev->dev, "Failed to allocate supply name\n");
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	drvdata->config = config;
+
+	drvdata->desc.type = REGULATOR_VOLTAGE;
+	drvdata->desc.ops = &ipq4019_regulator_voltage_ops;
+	drvdata->desc.n_voltages = config->nr_states;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	drvdata->config->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(drvdata->config->base)) {
+		ret = PTR_ERR(drvdata->config->base);
+		goto err_state;
+	}
+
+	cfg.dev = &pdev->dev;
+	cfg.init_data = config->init_data;
+	cfg.driver_data = drvdata;
+	cfg.of_node = np;
+
+	drvdata->dev = regulator_register(&drvdata->desc, &cfg);
+	if (IS_ERR(drvdata->dev)) {
+		ret = PTR_ERR(drvdata->dev);
+		dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
+		goto err_state;
+	}
+
+	platform_set_drvdata(pdev, drvdata);
+
+	return 0;
+
+err_state:
+	kfree(drvdata->config->states);
+	kfree(drvdata->config);
+	kfree(drvdata->desc.name);
+err:
+	return ret;
+}
+
+static int ipq4019_regulator_remove(struct platform_device *pdev)
+{
+	struct ipq4019_regulator_data *drvdata = platform_get_drvdata(pdev);
+
+	regulator_unregister(drvdata->dev);
+
+	kfree(drvdata->config->states);
+	kfree(drvdata->config);
+	kfree(drvdata->desc.name);
+
+	return 0;
+}
+
+#if defined(CONFIG_OF)
+static const struct of_device_id regulator_ipq4019_of_match[] = {
+	{ .compatible = "qcom,regulator-ipq4019", },
+	{},
+};
+#endif
+
+static struct platform_driver ipq4019_regulator_driver = {
+	.probe		= ipq4019_regulator_probe,
+	.remove		= ipq4019_regulator_remove,
+	.driver		= {
+		.name		= "regulator-ipq4019",
+		.of_match_table = of_match_ptr(regulator_ipq4019_of_match),
+	},
+};
+
+static int __init ipq4019_regulator_init(void)
+{
+	return platform_driver_register(&ipq4019_regulator_driver);
+}
+subsys_initcall(ipq4019_regulator_init);
+
+static void __exit ipq4019_regulator_exit(void)
+{
+	platform_driver_unregister(&ipq4019_regulator_driver);
+}
+module_exit(ipq4019_regulator_exit);
+
+MODULE_DESCRIPTION("ipq4019 voltage regulator");
--
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