mfd: lp873x: Add lp873x PMIC support

The LP873X chip is a power management IC for Portable Navigation Systems
    and Tablet Computing devices. It contains the following components:

     - Regulators.
     - Configurable General Purpose Output Signals (GPO).

PMIC interacts with the main processor through i2c. PMIC has
couple of LDOs (Linear Regulators), couple of BUCKs (Step-Down DC-DC
Converter Cores) and GPOs (General Purpose Output Signals).

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 2d1fb64..69e51d0 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1224,6 +1224,20 @@
 	  This driver can also be built as a module.  If so, the module
 	  will be called tps65217.
 
+config MFD_TI_LP873X
+	tristate "TI LP873X Power Management IC"
+	depends on I2C
+	select MFD_CORE
+	select REGMAP_I2C
+	help
+	  If you say yes here then you get support for the LP873X series of
+	  Power Management Integrated Circuits (PMIC).
+	  These include voltage regulators, thermal protection, configurable
+	  General Purpose Outputs (GPO) that are used in portable devices.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called lp873x.
+
 config MFD_TPS65218
 	tristate "TI TPS65218 Power Management chips"
 	depends on I2C
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 2ba3ba3..42acbcd 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -22,6 +22,8 @@
 obj-$(CONFIG_HTC_PASIC3)	+= htc-pasic3.o
 obj-$(CONFIG_HTC_I2CPLD)	+= htc-i2cpld.o
 
+obj-$(CONFIG_MFD_TI_LP873X)	+= lp873x.o
+
 obj-$(CONFIG_MFD_DAVINCI_VOICECODEC)	+= davinci_voicecodec.o
 obj-$(CONFIG_MFD_DM355EVM_MSP)	+= dm355evm_msp.o
 obj-$(CONFIG_MFD_TI_AM335X_TSCADC)	+= ti_am335x_tscadc.o
diff --git a/drivers/mfd/lp873x.c b/drivers/mfd/lp873x.c
new file mode 100644
index 0000000..9af064c
--- /dev/null
+++ b/drivers/mfd/lp873x.c
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * Author: Keerthy <j-keerthy@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+
+#include <linux/mfd/lp873x.h>
+
+static const struct regmap_config lp873x_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = LP873X_REG_MAX,
+};
+
+static const struct mfd_cell lp873x_cells[] = {
+	{ .name = "lp873x-regulator", },
+	{ .name = "lp873x-gpio", },
+};
+
+static int lp873x_probe(struct i2c_client *client,
+			const struct i2c_device_id *ids)
+{
+	struct lp873x *lp873;
+	int ret;
+	unsigned int otpid;
+
+	lp873 = devm_kzalloc(&client->dev, sizeof(*lp873), GFP_KERNEL);
+	if (!lp873)
+		return -ENOMEM;
+
+	lp873->dev = &client->dev;
+
+	lp873->regmap = devm_regmap_init_i2c(client, &lp873x_regmap_config);
+	if (IS_ERR(lp873->regmap)) {
+		ret = PTR_ERR(lp873->regmap);
+		dev_err(lp873->dev,
+			"Failed to initialize register map: %d\n", ret);
+		return ret;
+	}
+
+	mutex_init(&lp873->lock);
+
+	ret = regmap_read(lp873->regmap, LP873X_REG_OTP_REV, &otpid);
+	if (ret) {
+		dev_err(lp873->dev, "Failed to read OTP ID\n");
+		return ret;
+	}
+
+	lp873->rev = otpid & LP873X_OTP_REV_OTP_ID;
+
+	i2c_set_clientdata(client, lp873);
+
+	ret = mfd_add_devices(lp873->dev, PLATFORM_DEVID_AUTO, lp873x_cells,
+			      ARRAY_SIZE(lp873x_cells), NULL, 0, NULL);
+
+	return ret;
+}
+
+static const struct of_device_id of_lp873x_match_table[] = {
+	{ .compatible = "ti,lp8733", },
+	{ .compatible = "ti,lp8732", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_lp873x_match_table);
+
+static const struct i2c_device_id lp873x_id_table[] = {
+	{ "lp873x", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, lp873x_id_table);
+
+static struct i2c_driver lp873x_driver = {
+	.driver	= {
+		.name	= "lp873x",
+		.of_match_table = of_lp873x_match_table,
+	},
+	.probe		= lp873x_probe,
+	.id_table	= lp873x_id_table,
+};
+module_i2c_driver(lp873x_driver);
+
+MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>");
+MODULE_DESCRIPTION("LP873X chip family Multi-Function Device driver");
+MODULE_LICENSE("GPL v2");