mfd: Add Ricoh RN5T618 PMIC core driver

Ricoh RN5T618 is a power management IC which integrates 3 step-down
DCDC converters, 7 low-dropout regulators, a Li-ion battery charger,
fuel gauge, ADC, GPIOs and a watchdog timer.

This commit adds a MFD core driver to support the I2C communication
with the device.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

3 files changed, 146 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index fc419da8d722..82f70dcab136 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -597,6 +597,17 @@ config MFD_RC5T583
 	  Additional drivers must be enabled in order to use the
 	  different functionality of the device.
 
+config MFD_RN5T618
+	tristate "Ricoh RN5T5618 PMIC"
+	depends on I2C
+	select MFD_CORE
+	select REGMAP_I2C
+	help
+	  Say yes here to add support for the Ricoh RN5T618 PMIC. This
+	  driver provides common support for accessing the device,
+	  additional drivers must be enabled in order to use the
+	  functionality of the device.
+
 config MFD_SEC_CORE
 	bool "SAMSUNG Electronics PMIC Series Support"
 	depends on I2C=y
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index d58068aa8aa9..aa5a73a5ba47 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -160,6 +160,7 @@ obj-$(CONFIG_MFD_INTEL_MSIC)	+= intel_msic.o
 obj-$(CONFIG_MFD_PALMAS)	+= palmas.o
 obj-$(CONFIG_MFD_VIPERBOARD)    += viperboard.o
 obj-$(CONFIG_MFD_RC5T583)	+= rc5t583.o rc5t583-irq.o
+obj-$(CONFIG_MFD_RN5T618)	+= rn5t618.o
 obj-$(CONFIG_MFD_SEC_CORE)	+= sec-core.o sec-irq.o
 obj-$(CONFIG_MFD_SYSCON)	+= syscon.o
 obj-$(CONFIG_MFD_LM3533)	+= lm3533-core.o lm3533-ctrlbank.o
diff --git a/drivers/mfd/rn5t618.c b/drivers/mfd/rn5t618.c
new file mode 100644
index 000000000000..666857192dbe
--- /dev/null
+++ b/drivers/mfd/rn5t618.c
@@ -0,0 +1,134 @@
+/*
+ * MFD core driver for Ricoh RN5T618 PMIC
+ *
+ * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/i2c.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/rn5t618.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+static const struct mfd_cell rn5t618_cells[] = {
+	{ .name = "rn5t618-regulator" },
+	{ .name = "rn5t618-wdt" },
+};
+
+static bool rn5t618_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case RN5T618_WATCHDOGCNT:
+	case RN5T618_DCIRQ:
+	case RN5T618_ILIMDATAH ... RN5T618_AIN0DATAL:
+	case RN5T618_IR_ADC1 ... RN5T618_IR_ADC3:
+	case RN5T618_IR_GPR:
+	case RN5T618_IR_GPF:
+	case RN5T618_MON_IOIN:
+	case RN5T618_INTMON:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config rn5t618_regmap_config = {
+	.reg_bits	= 8,
+	.val_bits	= 8,
+	.volatile_reg	= rn5t618_volatile_reg,
+	.max_register	= RN5T618_MAX_REG,
+	.cache_type	= REGCACHE_RBTREE,
+};
+
+static struct rn5t618 *rn5t618_pm_power_off;
+
+static void rn5t618_power_off(void)
+{
+	/* disable automatic repower-on */
+	regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_REPCNT,
+			   RN5T618_REPCNT_REPWRON, 0);
+	/* start power-off sequence */
+	regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_SLPCNT,
+			   RN5T618_SLPCNT_SWPWROFF, RN5T618_SLPCNT_SWPWROFF);
+}
+
+static int rn5t618_i2c_probe(struct i2c_client *i2c,
+			     const struct i2c_device_id *id)
+{
+	struct rn5t618 *priv;
+	int ret;
+
+	priv = devm_kzalloc(&i2c->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	i2c_set_clientdata(i2c, priv);
+
+	priv->regmap = devm_regmap_init_i2c(i2c, &rn5t618_regmap_config);
+	if (IS_ERR(priv->regmap)) {
+		ret = PTR_ERR(priv->regmap);
+		dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = mfd_add_devices(&i2c->dev, -1, rn5t618_cells,
+			      ARRAY_SIZE(rn5t618_cells), NULL, 0, NULL);
+	if (ret) {
+		dev_err(&i2c->dev, "failed to add sub-devices: %d\n", ret);
+		return ret;
+	}
+
+	if (!pm_power_off) {
+		rn5t618_pm_power_off = priv;
+		pm_power_off = rn5t618_power_off;
+	}
+
+	return 0;
+}
+
+static int rn5t618_i2c_remove(struct i2c_client *i2c)
+{
+	struct rn5t618 *priv = i2c_get_clientdata(i2c);
+
+	if (priv == rn5t618_pm_power_off) {
+		rn5t618_pm_power_off = NULL;
+		pm_power_off = NULL;
+	}
+
+	mfd_remove_devices(&i2c->dev);
+	return 0;
+}
+
+static const struct of_device_id rn5t618_of_match[] = {
+	{ .compatible = "ricoh,rn5t618" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, rn5t618_of_match);
+
+static const struct i2c_device_id rn5t618_i2c_id[] = {
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, rn5t618_i2c_id);
+
+static struct i2c_driver rn5t618_i2c_driver = {
+	.driver = {
+		.name = "rn5t618",
+		.of_match_table = of_match_ptr(rn5t618_of_match),
+	},
+	.probe = rn5t618_i2c_probe,
+	.remove = rn5t618_i2c_remove,
+	.id_table = rn5t618_i2c_id,
+};
+
+module_i2c_driver(rn5t618_i2c_driver);
+
+MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
+MODULE_DESCRIPTION("Ricoh RN5T618 MFD driver");
+MODULE_LICENSE("GPL v2");