mfd: Add Maxim 77686 driver

This patch is device driver for MAX77686 chip.
MAX77686 is PMIC and includes regulator and rtc on it.
This driver is core of MAX77686 chip, so provides common support for
accessing on-chip devices. It uses irq_domain to manage irq and regmap
to read/write data to its register with i2c bus.

Signed-off-by: Chiwoong Byun <woong.byun@samsung.com>
Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 156 insertions, 0 deletions

diff --git a/drivers/mfd/max77686.c b/drivers/mfd/max77686.c
new file mode 100644
index 0000000..11e5601
--- /dev/null
+++ b/drivers/mfd/max77686.c
@@ -0,0 +1,156 @@
+/*
+ * max77686.c - mfd core driver for the Maxim 77686
+ *
+ * Copyright (C) 2012 Samsung Electronics
+ * Chiwoong Byun <woong.byun@smasung.com>
+ * Jonghwa Lee <jonghwa3.lee@samsung.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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * This driver is based on max8997.c
+ */
+
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/pm_runtime.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/max77686.h>
+#include <linux/mfd/max77686-private.h>
+#include <linux/err.h>
+
+#define I2C_ADDR_RTC	(0x0C >> 1)
+
+static struct mfd_cell max77686_devs[] = {
+	{ .name = "max77686-pmic", },
+	{ .name = "max77686-rtc", },
+};
+
+static struct regmap_config max77686_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static int max77686_i2c_probe(struct i2c_client *i2c,
+			      const struct i2c_device_id *id)
+{
+	struct max77686_dev *max77686;
+	struct max77686_platform_data *pdata = i2c->dev.platform_data;
+	unsigned int data;
+	int ret = 0;
+
+	max77686 = kzalloc(sizeof(struct max77686_dev), GFP_KERNEL);
+	if (max77686 == NULL)
+		return -ENOMEM;
+
+	max77686->regmap = regmap_init_i2c(i2c, &max77686_regmap_config);
+	if (IS_ERR(max77686->regmap)) {
+		ret = PTR_ERR(max77686->regmap);
+		dev_err(max77686->dev, "Failed to allocate register map: %d\n",
+				ret);
+		kfree(max77686);
+		return ret;
+	}
+
+	i2c_set_clientdata(i2c, max77686);
+	max77686->dev = &i2c->dev;
+	max77686->i2c = i2c;
+	max77686->type = id->driver_data;
+
+	if (!pdata) {
+		ret = -EIO;
+		goto err;
+	}
+
+	max77686->wakeup = pdata->wakeup;
+	max77686->irq_gpio = pdata->irq_gpio;
+
+	mutex_init(&max77686->iolock);
+
+	if (regmap_read(max77686->regmap,
+			 MAX77686_REG_DEVICE_ID, &data) < 0) {
+		dev_err(max77686->dev,
+			"device not found on this channel (this is not an error)\n");
+		ret = -ENODEV;
+		goto err;
+	} else
+		dev_info(max77686->dev, "device found\n");
+
+	max77686->rtc = i2c_new_dummy(i2c->adapter, I2C_ADDR_RTC);
+	i2c_set_clientdata(max77686->rtc, max77686);
+
+	max77686_irq_init(max77686);
+
+	ret = mfd_add_devices(max77686->dev, -1, max77686_devs,
+			      ARRAY_SIZE(max77686_devs), NULL, 0);
+
+	if (ret < 0)
+		goto err_mfd;
+
+	return ret;
+
+err_mfd:
+	mfd_remove_devices(max77686->dev);
+	i2c_unregister_device(max77686->rtc);
+err:
+	kfree(max77686);
+	return ret;
+}
+
+static int max77686_i2c_remove(struct i2c_client *i2c)
+{
+	struct max77686_dev *max77686 = i2c_get_clientdata(i2c);
+
+	mfd_remove_devices(max77686->dev);
+	i2c_unregister_device(max77686->rtc);
+	kfree(max77686);
+
+	return 0;
+}
+
+static const struct i2c_device_id max77686_i2c_id[] = {
+	{ "max77686", TYPE_MAX77686 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max77686_i2c_id);
+
+static struct i2c_driver max77686_i2c_driver = {
+	.driver = {
+		   .name = "max77686",
+		   .owner = THIS_MODULE,
+	},
+	.probe = max77686_i2c_probe,
+	.remove = max77686_i2c_remove,
+	.id_table = max77686_i2c_id,
+};
+
+static int __init max77686_i2c_init(void)
+{
+	return i2c_add_driver(&max77686_i2c_driver);
+}
+/* init early so consumer devices can complete system boot */
+subsys_initcall(max77686_i2c_init);
+
+static void __exit max77686_i2c_exit(void)
+{
+	i2c_del_driver(&max77686_i2c_driver);
+}
+module_exit(max77686_i2c_exit);
+
+MODULE_DESCRIPTION("MAXIM 77686 multi-function core driver");
+MODULE_AUTHOR("Chiwoong Byun <woong.byun@samsung.com>");
+MODULE_LICENSE("GPL");