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>

4 files changed, 479 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index e129c820df7d..a7d0c851afc5 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -422,6 +422,19 @@ config PMIC_ADP5520
 	  individual components like LCD backlight, LEDs, GPIOs and Kepad
 	  under the corresponding menus.
 
+config MFD_MAX77686
+	bool "Maxim Semiconductor MAX77686 PMIC Support"
+	depends on I2C=y && GENERIC_HARDIRQS
+	select MFD_CORE
+	select REGMAP_I2C
+	select IRQ_DOMAIN
+	help
+	  Say yes here to support for Maxim Semiconductor MAX77686.
+	  This is a Power Management IC with RTC on chip.
+	  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_MAX77693
 	bool "Maxim Semiconductor MAX77693 PMIC Support"
 	depends on I2C=y && GENERIC_HARDIRQS
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 75f6ed68a4b9..8ee7a3bf595b 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -78,6 +78,7 @@ obj-$(CONFIG_PMIC_DA9052)	+= da9052-core.o
 obj-$(CONFIG_MFD_DA9052_SPI)	+= da9052-spi.o
 obj-$(CONFIG_MFD_DA9052_I2C)	+= da9052-i2c.o
 
+obj-$(CONFIG_MFD_MAX77686)	+= max77686.o max77686-irq.o
 obj-$(CONFIG_MFD_MAX77693)	+= max77693.o max77693-irq.o
 max8925-objs			:= max8925-core.o max8925-i2c.o
 obj-$(CONFIG_MFD_MAX8925)	+= max8925.o
diff --git a/drivers/mfd/max77686-irq.c b/drivers/mfd/max77686-irq.c
new file mode 100644
index 000000000000..fc101220f990
--- /dev/null
+++ b/drivers/mfd/max77686-irq.c
@@ -0,0 +1,309 @@
+/*
+ * max77686-irq.c - Interrupt controller support for MAX77686
+ *
+ * Copyright (C) 2012 Samsung Electronics Co.Ltd
+ * Chiwoong Byun <woong.byun@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-irq.c
+ */
+
+#include <linux/err.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include <linux/mfd/max77686.h>
+#include <linux/mfd/max77686-private.h>
+#include <linux/irqdomain.h>
+#include <linux/regmap.h>
+
+enum {
+	MAX77686_DEBUG_IRQ_INFO = 1 << 0,
+	MAX77686_DEBUG_IRQ_MASK = 1 << 1,
+	MAX77686_DEBUG_IRQ_INT = 1 << 2,
+};
+
+static int debug_mask = 0;
+module_param(debug_mask, int, 0);
+MODULE_PARM_DESC(debug_mask, "Set debug_mask : 0x0=off 0x1=IRQ_INFO  0x2=IRQ_MASK 0x4=IRQ_INI)");
+
+static const u8 max77686_mask_reg[] = {
+	[PMIC_INT1] = MAX77686_REG_INT1MSK,
+	[PMIC_INT2] = MAX77686_REG_INT2MSK,
+	[RTC_INT] = MAX77686_RTC_INTM,
+};
+
+static struct regmap *max77686_get_regmap(struct max77686_dev *max77686,
+				enum max77686_irq_source src)
+{
+	switch (src) {
+	case PMIC_INT1 ... PMIC_INT2:
+		return max77686->regmap;
+	case RTC_INT:
+		return max77686->rtc_regmap;
+	default:
+		return ERR_PTR(-EINVAL);
+	}
+}
+
+struct max77686_irq_data {
+	int mask;
+	enum max77686_irq_source group;
+};
+
+#define DECLARE_IRQ(idx, _group, _mask)		\
+	[(idx)] = { .group = (_group), .mask = (_mask) }
+static const struct max77686_irq_data max77686_irqs[] = {
+	DECLARE_IRQ(MAX77686_PMICIRQ_PWRONF,	PMIC_INT1, 1 << 0),
+	DECLARE_IRQ(MAX77686_PMICIRQ_PWRONR,	PMIC_INT1, 1 << 1),
+	DECLARE_IRQ(MAX77686_PMICIRQ_JIGONBF,	PMIC_INT1, 1 << 2),
+	DECLARE_IRQ(MAX77686_PMICIRQ_JIGONBR,	PMIC_INT1, 1 << 3),
+	DECLARE_IRQ(MAX77686_PMICIRQ_ACOKBF,	PMIC_INT1, 1 << 4),
+	DECLARE_IRQ(MAX77686_PMICIRQ_ACOKBR,	PMIC_INT1, 1 << 5),
+	DECLARE_IRQ(MAX77686_PMICIRQ_ONKEY1S,	PMIC_INT1, 1 << 6),
+	DECLARE_IRQ(MAX77686_PMICIRQ_MRSTB,		PMIC_INT1, 1 << 7),
+	DECLARE_IRQ(MAX77686_PMICIRQ_140C,		PMIC_INT2, 1 << 0),
+	DECLARE_IRQ(MAX77686_PMICIRQ_120C,		PMIC_INT2, 1 << 1),
+	DECLARE_IRQ(MAX77686_RTCIRQ_RTC60S,		RTC_INT, 1 << 0),
+	DECLARE_IRQ(MAX77686_RTCIRQ_RTCA1,		RTC_INT, 1 << 1),
+	DECLARE_IRQ(MAX77686_RTCIRQ_RTCA2,		RTC_INT, 1 << 2),
+	DECLARE_IRQ(MAX77686_RTCIRQ_SMPL,		RTC_INT, 1 << 3),
+	DECLARE_IRQ(MAX77686_RTCIRQ_RTC1S,		RTC_INT, 1 << 4),
+	DECLARE_IRQ(MAX77686_RTCIRQ_WTSR,		RTC_INT, 1 << 5),
+};
+
+static void max77686_irq_lock(struct irq_data *data)
+{
+	struct max77686_dev *max77686 = irq_get_chip_data(data->irq);
+
+	if (debug_mask & MAX77686_DEBUG_IRQ_MASK)
+		pr_info("%s\n", __func__);
+
+	mutex_lock(&max77686->irqlock);
+}
+
+static void max77686_irq_sync_unlock(struct irq_data *data)
+{
+	struct max77686_dev *max77686 = irq_get_chip_data(data->irq);
+	int i;
+
+	for (i = 0; i < MAX77686_IRQ_GROUP_NR; i++) {
+		u8 mask_reg = max77686_mask_reg[i];
+		struct regmap *map = max77686_get_regmap(max77686, i);
+
+		if (debug_mask & MAX77686_DEBUG_IRQ_MASK)
+			pr_debug("%s: mask_reg[%d]=0x%x, cur=0x%x\n",
+			__func__, i, mask_reg, max77686->irq_masks_cur[i]);
+
+		if (mask_reg == MAX77686_REG_INVALID ||
+				IS_ERR_OR_NULL(map))
+			continue;
+
+		max77686->irq_masks_cache[i] = max77686->irq_masks_cur[i];
+
+		regmap_write(map, max77686_mask_reg[i],
+				max77686->irq_masks_cur[i]);
+	}
+
+	mutex_unlock(&max77686->irqlock);
+}
+
+static const inline struct max77686_irq_data *to_max77686_irq(int irq)
+{
+	struct irq_data *data = irq_get_irq_data(irq);
+	return &max77686_irqs[data->hwirq];
+}
+
+static void max77686_irq_mask(struct irq_data *data)
+{
+	struct max77686_dev *max77686 = irq_get_chip_data(data->irq);
+	const struct max77686_irq_data *irq_data = to_max77686_irq(data->irq);
+
+	max77686->irq_masks_cur[irq_data->group] |= irq_data->mask;
+
+	if (debug_mask & MAX77686_DEBUG_IRQ_MASK)
+		pr_info("%s: group=%d, cur=0x%x\n",
+			__func__, irq_data->group,
+			max77686->irq_masks_cur[irq_data->group]);
+}
+
+static void max77686_irq_unmask(struct irq_data *data)
+{
+	struct max77686_dev *max77686 = irq_get_chip_data(data->irq);
+	const struct max77686_irq_data *irq_data = to_max77686_irq(data->irq);
+
+	max77686->irq_masks_cur[irq_data->group] &= ~irq_data->mask;
+
+	if (debug_mask & MAX77686_DEBUG_IRQ_MASK)
+		pr_info("%s: group=%d, cur=0x%x\n",
+			__func__, irq_data->group,
+			max77686->irq_masks_cur[irq_data->group]);
+}
+
+static struct irq_chip max77686_irq_chip = {
+	.name			= "max77686",
+	.irq_bus_lock		= max77686_irq_lock,
+	.irq_bus_sync_unlock	= max77686_irq_sync_unlock,
+	.irq_mask		= max77686_irq_mask,
+	.irq_unmask		= max77686_irq_unmask,
+};
+
+static irqreturn_t max77686_irq_thread(int irq, void *data)
+{
+	struct max77686_dev *max77686 = data;
+	unsigned int irq_reg[MAX77686_IRQ_GROUP_NR] = {};
+	unsigned int irq_src;
+	int ret;
+	int i, cur_irq;
+
+	ret = regmap_read(max77686->regmap,  MAX77686_REG_INTSRC, &irq_src);
+	if (ret < 0) {
+		dev_err(max77686->dev, "Failed to read interrupt source: %d\n",
+				ret);
+		return IRQ_NONE;
+	}
+
+	if (debug_mask & MAX77686_DEBUG_IRQ_INT)
+		pr_info("%s: irq_src=0x%x\n", __func__, irq_src);
+
+	if (irq_src == MAX77686_IRQSRC_PMIC) {
+		ret = regmap_bulk_read(max77686->rtc_regmap,
+					 MAX77686_REG_INT1, irq_reg, 2);
+		if (ret < 0) {
+			dev_err(max77686->dev, "Failed to read interrupt source: %d\n",
+					ret);
+			return IRQ_NONE;
+		}
+
+		if (debug_mask & MAX77686_DEBUG_IRQ_INT)
+			pr_info("%s: int1=0x%x, int2=0x%x\n", __func__,
+				 irq_reg[PMIC_INT1], irq_reg[PMIC_INT2]);
+	}
+
+	if (irq_src & MAX77686_IRQSRC_RTC) {
+		ret = regmap_read(max77686->rtc_regmap,
+					MAX77686_RTC_INT, &irq_reg[RTC_INT]);
+		if (ret < 0) {
+			dev_err(max77686->dev, "Failed to read interrupt source: %d\n",
+					ret);
+			return IRQ_NONE;
+		}
+
+		if (debug_mask & MAX77686_DEBUG_IRQ_INT)
+			pr_info("%s: rtc int=0x%x\n", __func__,
+							 irq_reg[RTC_INT]);
+
+	}
+
+	for (i = 0; i < MAX77686_IRQ_NR; i++) {
+		if (irq_reg[max77686_irqs[i].group] & max77686_irqs[i].mask) {
+			cur_irq = irq_find_mapping(max77686->irq_domain, i);
+			if (cur_irq)
+				handle_nested_irq(cur_irq);
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int max77686_irq_domain_map(struct irq_domain *d, unsigned int irq,
+					irq_hw_number_t hw)
+{
+	struct max77686_dev *max77686 = d->host_data;
+
+	irq_set_chip_data(irq, max77686);
+	irq_set_chip_and_handler(irq, &max77686_irq_chip, handle_edge_irq);
+	irq_set_nested_thread(irq, 1);
+#ifdef CONFIG_ARM
+	set_irq_flags(irq, IRQF_VALID);
+#else
+	irq_set_noprobe(irq);
+#endif
+	return 0;
+}
+
+static struct irq_domain_ops max77686_irq_domain_ops = {
+	.map = max77686_irq_domain_map,
+};
+
+int max77686_irq_init(struct max77686_dev *max77686)
+{
+	struct irq_domain *domain;
+	int i;
+	int ret;
+	int val;
+	struct regmap *map;
+
+	mutex_init(&max77686->irqlock);
+
+	max77686->irq = gpio_to_irq(max77686->irq_gpio);
+
+	if (debug_mask & MAX77686_DEBUG_IRQ_INT) {
+		ret = gpio_request(max77686->irq_gpio, "pmic_irq");
+		if (ret < 0) {
+			dev_err(max77686->dev,
+				"Failed to request gpio %d with ret: %d\n",
+				max77686->irq_gpio, ret);
+			return IRQ_NONE;
+		}
+
+		gpio_direction_input(max77686->irq_gpio);
+		val = gpio_get_value(max77686->irq_gpio);
+		gpio_free(max77686->irq_gpio);
+		pr_info("%s: gpio_irq=%x\n", __func__, val);
+	}
+
+	/* Mask individual interrupt sources */
+	for (i = 0; i < MAX77686_IRQ_GROUP_NR; i++) {
+		max77686->irq_masks_cur[i] = 0xff;
+		max77686->irq_masks_cache[i] = 0xff;
+		map = max77686_get_regmap(max77686, i);
+
+		if (IS_ERR_OR_NULL(map))
+			continue;
+		if (max77686_mask_reg[i] == MAX77686_REG_INVALID)
+			continue;
+
+		regmap_write(map, max77686_mask_reg[i], 0xff);
+	}
+	domain = irq_domain_add_linear(NULL, MAX77686_IRQ_NR,
+					&max77686_irq_domain_ops, max77686);
+	if (!domain) {
+		dev_err(max77686->dev, "could not create irq domain\n");
+		return -ENODEV;
+	}
+	max77686->irq_domain = domain;
+
+	ret = request_threaded_irq(max77686->irq, NULL, max77686_irq_thread,
+				   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+				   "max77686-irq", max77686);
+
+	if (ret)
+		dev_err(max77686->dev, "Failed to request IRQ %d: %d\n",
+			max77686->irq, ret);
+
+
+	if (debug_mask & MAX77686_DEBUG_IRQ_INFO)
+		pr_info("%s-\n", __func__);
+
+	return 0;
+}
+
+void max77686_irq_exit(struct max77686_dev *max77686)
+{
+	if (max77686->irq)
+		free_irq(max77686->irq, max77686);
+}
diff --git a/drivers/mfd/max77686.c b/drivers/mfd/max77686.c
new file mode 100644
index 000000000000..11e56017e0b0
--- /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");