mfd: tps65218: Add driver for the TPS65218 PMIC

The TPS65218 chip is a power management IC for Portable Navigation Systems
and Tablet Computing devices. It contains the following components:

 - Regulators.
 - Over Temperature warning and Shut down.

This patch adds support for tps65218 mfd device. At this time only
the regulator functionality is made available.

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 30fbacf..3e2d698 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -853,6 +853,21 @@
 	  This driver can also be built as a module.  If so, the module
 	  will be called tps65217.
 
+config MFD_TPS65218
+	tristate "TI TPS65218 Power Management chips"
+	depends on I2C
+	select MFD_CORE
+	select REGMAP_I2C
+	help
+	  If you say yes here you get support for the TPS65218 series of
+	  Power Management chips.
+	  These include voltage regulators, gpio and other features
+	  that are often used in portable devices. Only regulator
+	  component is currently supported.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called tps65218.
+
 config MFD_TPS6586X
 	bool "TI TPS6586x Power Management chips"
 	depends on I2C=y
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index c8eb0bc..5e5cfbd 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -62,6 +62,7 @@
 obj-$(CONFIG_TPS65010)		+= tps65010.o
 obj-$(CONFIG_TPS6507X)		+= tps6507x.o
 obj-$(CONFIG_MFD_TPS65217)	+= tps65217.o
+obj-$(CONFIG_MFD_TPS65218)	+= tps65218.o
 obj-$(CONFIG_MFD_TPS65910)	+= tps65910.o
 tps65912-objs                   := tps65912-core.o tps65912-irq.o
 obj-$(CONFIG_MFD_TPS65912)	+= tps65912.o
diff --git a/drivers/mfd/tps65218.c b/drivers/mfd/tps65218.c
new file mode 100644
index 0000000..a74bfb5
--- /dev/null
+++ b/drivers/mfd/tps65218.c
@@ -0,0 +1,282 @@
+/*
+ * Driver for TPS65218 Integrated power management chipsets
+ *
+ * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether expressed or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License version 2 for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/mutex.h>
+
+#include <linux/mfd/core.h>
+#include <linux/mfd/tps65218.h>
+
+#define TPS65218_PASSWORD_REGS_UNLOCK   0x7D
+
+/**
+ * tps65218_reg_read: Read a single tps65218 register.
+ *
+ * @tps: Device to read from.
+ * @reg: Register to read.
+ * @val: Contians the value
+ */
+int tps65218_reg_read(struct tps65218 *tps, unsigned int reg,
+			unsigned int *val)
+{
+	return regmap_read(tps->regmap, reg, val);
+}
+EXPORT_SYMBOL_GPL(tps65218_reg_read);
+
+/**
+ * tps65218_reg_write: Write a single tps65218 register.
+ *
+ * @tps65218: Device to write to.
+ * @reg: Register to write to.
+ * @val: Value to write.
+ * @level: Password protected level
+ */
+int tps65218_reg_write(struct tps65218 *tps, unsigned int reg,
+			unsigned int val, unsigned int level)
+{
+	int ret;
+	unsigned int xor_reg_val;
+
+	switch (level) {
+	case TPS65218_PROTECT_NONE:
+		return regmap_write(tps->regmap, reg, val);
+	case TPS65218_PROTECT_L1:
+		xor_reg_val = reg ^ TPS65218_PASSWORD_REGS_UNLOCK;
+		ret = regmap_write(tps->regmap, TPS65218_REG_PASSWORD,
+							xor_reg_val);
+		if (ret < 0)
+			return ret;
+
+		return regmap_write(tps->regmap, reg, val);
+	default:
+		return -EINVAL;
+	}
+}
+EXPORT_SYMBOL_GPL(tps65218_reg_write);
+
+/**
+ * tps65218_update_bits: Modify bits w.r.t mask, val and level.
+ *
+ * @tps65218: Device to write to.
+ * @reg: Register to read-write to.
+ * @mask: Mask.
+ * @val: Value to write.
+ * @level: Password protected level
+ */
+static int tps65218_update_bits(struct tps65218 *tps, unsigned int reg,
+		unsigned int mask, unsigned int val, unsigned int level)
+{
+	int ret;
+	unsigned int data;
+
+	ret = tps65218_reg_read(tps, reg, &data);
+	if (ret) {
+		dev_err(tps->dev, "Read from reg 0x%x failed\n", reg);
+		return ret;
+	}
+
+	data &= ~mask;
+	data |= val & mask;
+
+	mutex_lock(&tps->tps_lock);
+	ret = tps65218_reg_write(tps, reg, data, level);
+	if (ret)
+		dev_err(tps->dev, "Write for reg 0x%x failed\n", reg);
+	mutex_unlock(&tps->tps_lock);
+
+	return ret;
+}
+
+int tps65218_set_bits(struct tps65218 *tps, unsigned int reg,
+		unsigned int mask, unsigned int val, unsigned int level)
+{
+	return tps65218_update_bits(tps, reg, mask, val, level);
+}
+EXPORT_SYMBOL_GPL(tps65218_set_bits);
+
+int tps65218_clear_bits(struct tps65218 *tps, unsigned int reg,
+		unsigned int mask, unsigned int level)
+{
+	return tps65218_update_bits(tps, reg, mask, 0, level);
+}
+EXPORT_SYMBOL_GPL(tps65218_clear_bits);
+
+static struct regmap_config tps65218_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.cache_type = REGCACHE_RBTREE,
+};
+
+static const struct regmap_irq tps65218_irqs[] = {
+	/* INT1 IRQs */
+	[TPS65218_PRGC_IRQ] = {
+		.mask = TPS65218_INT1_PRGC,
+	},
+	[TPS65218_CC_AQC_IRQ] = {
+		.mask = TPS65218_INT1_CC_AQC,
+	},
+	[TPS65218_HOT_IRQ] = {
+		.mask = TPS65218_INT1_HOT,
+	},
+	[TPS65218_PB_IRQ] = {
+		.mask = TPS65218_INT1_PB,
+	},
+	[TPS65218_AC_IRQ] = {
+		.mask = TPS65218_INT1_AC,
+	},
+	[TPS65218_VPRG_IRQ] = {
+		.mask = TPS65218_INT1_VPRG,
+	},
+	[TPS65218_INVALID1_IRQ] = {
+	},
+	[TPS65218_INVALID2_IRQ] = {
+	},
+	/* INT2 IRQs*/
+	[TPS65218_LS1_I_IRQ] = {
+		.mask = TPS65218_INT2_LS1_I,
+		.reg_offset = 1,
+	},
+	[TPS65218_LS2_I_IRQ] = {
+		.mask = TPS65218_INT2_LS2_I,
+		.reg_offset = 1,
+	},
+	[TPS65218_LS3_I_IRQ] = {
+		.mask = TPS65218_INT2_LS3_I,
+		.reg_offset = 1,
+	},
+	[TPS65218_LS1_F_IRQ] = {
+		.mask = TPS65218_INT2_LS1_F,
+		.reg_offset = 1,
+	},
+	[TPS65218_LS2_F_IRQ] = {
+		.mask = TPS65218_INT2_LS2_F,
+		.reg_offset = 1,
+	},
+	[TPS65218_LS3_F_IRQ] = {
+		.mask = TPS65218_INT2_LS3_F,
+		.reg_offset = 1,
+	},
+	[TPS65218_INVALID3_IRQ] = {
+	},
+	[TPS65218_INVALID4_IRQ] = {
+	},
+};
+
+static struct regmap_irq_chip tps65218_irq_chip = {
+	.name = "tps65218",
+	.irqs = tps65218_irqs,
+	.num_irqs = ARRAY_SIZE(tps65218_irqs),
+
+	.num_regs = 2,
+	.mask_base = TPS65218_REG_INT_MASK1,
+};
+
+static const struct of_device_id of_tps65218_match_table[] = {
+	{ .compatible = "ti,tps65218", },
+};
+
+static int tps65218_probe(struct i2c_client *client,
+				const struct i2c_device_id *ids)
+{
+	struct tps65218 *tps;
+	const struct of_device_id *match;
+	int ret;
+
+	match = of_match_device(of_tps65218_match_table, &client->dev);
+	if (!match) {
+		dev_err(&client->dev,
+			"Failed to find matching dt id\n");
+		return -EINVAL;
+	}
+
+	tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL);
+	if (!tps)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, tps);
+	tps->dev = &client->dev;
+	tps->irq = client->irq;
+	tps->regmap = devm_regmap_init_i2c(client, &tps65218_regmap_config);
+	if (IS_ERR(tps->regmap)) {
+		ret = PTR_ERR(tps->regmap);
+		dev_err(tps->dev, "Failed to allocate register map: %d\n",
+			ret);
+		return ret;
+	}
+
+	mutex_init(&tps->tps_lock);
+
+	ret = regmap_add_irq_chip(tps->regmap, tps->irq,
+			IRQF_ONESHOT, 0, &tps65218_irq_chip,
+			&tps->irq_data);
+	if (ret < 0)
+		return ret;
+
+	ret = of_platform_populate(client->dev.of_node, NULL, NULL,
+				   &client->dev);
+	if (ret < 0)
+		goto err_irq;
+
+	return 0;
+
+err_irq:
+	regmap_del_irq_chip(tps->irq, tps->irq_data);
+
+	return ret;
+}
+
+static int tps65218_remove(struct i2c_client *client)
+{
+	struct tps65218 *tps = i2c_get_clientdata(client);
+
+	regmap_del_irq_chip(tps->irq, tps->irq_data);
+
+	return 0;
+}
+
+static const struct i2c_device_id tps65218_id_table[] = {
+	{ "tps65218", TPS65218 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, tps65218_id_table);
+
+static struct i2c_driver tps65218_driver = {
+	.driver		= {
+		.name	= "tps65218",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_tps65218_match_table,
+	},
+	.probe		= tps65218_probe,
+	.remove		= tps65218_remove,
+	.id_table       = tps65218_id_table,
+};
+
+module_i2c_driver(tps65218_driver);
+
+MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>");
+MODULE_DESCRIPTION("TPS65218 chip family multi-function driver");
+MODULE_LICENSE("GPL v2");