[PATCH 2/2] mfd: max7360: Add mfd core device driver

[Valentin Sitdikov <valentin_sitdikov@mentor.com>]

From: Andrei Dranitca <Andrei_Dranitca@mentor.com>

This patch adds core/irq driver to support MAX7360 i2c chip
which contains keypad, gpio, pwm, gpo and rotary encoder submodules.

Signed-off-by: Valentin Sitdikov <valentin_sitdikov@mentor.com>
Signed-off-by: Andrei Dranitca <Andrei_Dranitca@mentor.com>
---
 drivers/mfd/Kconfig         |  16 ++
 drivers/mfd/Makefile        |   1 +
 drivers/mfd/max7360.c       | 393 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/max7360.h | 130 +++++++++++++++
 4 files changed, 540 insertions(+)
 create mode 100644 drivers/mfd/max7360.c
 create mode 100644 include/linux/mfd/max7360.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 55ecdfb..2227c65 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -688,6 +688,22 @@ config MFD_MAX8998
 	  additional drivers must be enabled in order to use the functionality
 	  of the device.
 
+config MFD_MAX7360
+	tristate "Maxim Semiconductor MAX7360 support"
+	depends on I2C && OF
+	select MFD_CORE
+	select REGMAP_I2C
+	select IRQ_DOMAIN
+	help
+	  Say yes here to add support for Maxim Semiconductor MAX7360.
+	  This provides microprocessors with management of up to 64 key switches,
+	  with an additional eight LED drivers/GPIOs that feature constant-current,
+	  PWM intensity control, and rotary switch control options.
+
+	  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_MT6397
 	tristate "MediaTek MT6397 PMIC Support"
 	select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 31ce076..f01f3a1 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -133,6 +133,7 @@ obj-$(CONFIG_MFD_DA9063)	+= da9063.o
 obj-$(CONFIG_MFD_DA9150)	+= da9150-core.o
 
 obj-$(CONFIG_MFD_MAX14577)	+= max14577.o
+obj-$(CONFIG_MFD_MAX7360)	+= max7360.o
 obj-$(CONFIG_MFD_MAX77620)	+= max77620.o
 obj-$(CONFIG_MFD_MAX77686)	+= max77686.o
 obj-$(CONFIG_MFD_MAX77693)	+= max77693.o
diff --git a/drivers/mfd/max7360.c b/drivers/mfd/max7360.c
new file mode 100644
index 0000000..b4c2fdd
--- /dev/null
+++ b/drivers/mfd/max7360.c
@@ -0,0 +1,393 @@
+/*
+ * Copyright (C) 2017 Mentor Graphics
+ *
+ * Author: Valentin Sitdikov <Valentin.Sitdikov@mentor.com>
+ * Author: Andrei Dranitca <Andrei_Dranitca@mentor.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.
+ *
+ */
+
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/max7360.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+
+
+int max7360_request_pin(struct max7360 *max7360, u8 pin)
+{
+	struct i2c_client *client = max7360->i2c;
+	int ret = 0;
+
+	spin_lock(&max7360->lock);
+	if (max7360->gpio_pins & BIT(pin)) {
+		dev_err(&client->dev, "pin %d already requested, mask %x",
+		       pin, max7360->gpio_pins);
+		spin_unlock(&max7360->lock);
+		return -EBUSY;
+	}
+	max7360->gpio_pins |= BIT(pin);
+	dev_dbg(&client->dev, "pin %d requested successfully", pin);
+	spin_unlock(&max7360->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(max7360_request_pin);
+
+void max7360_free_pin(struct max7360 *max7360, u8 pin)
+{
+	spin_lock(&max7360->lock);
+	max7360->gpio_pins &= ~BIT(pin);
+	spin_unlock(&max7360->lock);
+}
+EXPORT_SYMBOL_GPL(max7360_free_pin);
+
+static const struct mfd_cell max7360_devices[] = {
+	{
+		.name           = "max7360-gpio",
+		.of_compatible	= "maxim,max7360-gpio",
+	},
+	{
+		.name           = "max7360-keypad",
+		.of_compatible	= "maxim,max7360-keypad",
+	},
+	{
+		.name           = "max7360-pwm",
+		.of_compatible	= "maxim,max7360-pwm",
+	},
+	{
+		.name           = "max7360-rotary",
+		.of_compatible	= "maxim,max7360-rotary",
+	},
+};
+
+static irqreturn_t max7360_irq(int irq, void *data)
+{
+	struct max7360 *max7360 = data;
+	int virq;
+
+	virq = irq_find_mapping(max7360->domain, MAX7360_INT_GPIO);
+	handle_nested_irq(virq);
+	virq = irq_find_mapping(max7360->domain, MAX7360_INT_KEYPAD);
+	handle_nested_irq(virq);
+	virq = irq_find_mapping(max7360->domain, MAX7360_INT_ROTARY);
+	handle_nested_irq(virq);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t max7360_irqi(int irq, void *data)
+{
+	struct max7360 *max7360 = data;
+	int virq;
+
+	virq = irq_find_mapping(max7360->domain, MAX7360_INT_GPIO);
+	handle_nested_irq(virq);
+	virq = irq_find_mapping(max7360->domain, MAX7360_INT_ROTARY);
+	handle_nested_irq(virq);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t max7360_irqk(int irq, void *data)
+{
+	struct max7360 *max7360 = data;
+	int virq;
+
+	virq = irq_find_mapping(max7360->domain, MAX7360_INT_KEYPAD);
+	handle_nested_irq(virq);
+
+	return IRQ_HANDLED;
+}
+
+static int max7360_irq_map(struct irq_domain *d, unsigned int virq,
+			  irq_hw_number_t hwirq)
+{
+	struct max7360 *max7360 = d->host_data;
+
+	irq_set_chip_data(virq, max7360);
+	irq_set_chip_and_handler(virq, &dummy_irq_chip,
+				handle_edge_irq);
+	irq_set_nested_thread(virq, 1);
+	irq_set_noprobe(virq);
+
+	return 0;
+}
+
+static void max7360_irq_unmap(struct irq_domain *d, unsigned int virq)
+{
+	irq_set_chip_and_handler(virq, NULL, NULL);
+	irq_set_chip_data(virq, NULL);
+}
+
+static const struct irq_domain_ops max7360_irq_ops = {
+	.map    = max7360_irq_map,
+	.unmap  = max7360_irq_unmap,
+	.xlate  = irq_domain_xlate_onecell,
+};
+
+static int max7360_irq_init(struct max7360 *max7360, struct device_node *np)
+{
+	int ret;
+
+	max7360->inti = of_irq_get_byname(np, "inti");
+	max7360->intk = of_irq_get_byname(np, "intk");
+
+	if (max7360->inti < 0 || max7360->intk < 0) {
+		max7360->shared_irq = of_irq_get_byname(np, "int-shared");
+
+		if (max7360->shared_irq < 0) {
+			dev_err(max7360->dev, "failed to find IRQ in dts\n");
+			return -EINVAL;
+		}
+
+		ret = request_threaded_irq(max7360->shared_irq, NULL,
+					  max7360_irq,
+					  IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+					  "max7360", max7360);
+		if (ret) {
+			dev_err(max7360->dev, "failed to request IRQ: %d\n",
+				ret);
+			return ret;
+		}
+	} else {
+		max7360->shared_irq = 0;
+		ret = request_threaded_irq(max7360->inti, NULL, max7360_irqi,
+					  IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+					  "max7360", max7360);
+		if (ret) {
+			dev_err(max7360->dev, "failed to request inti IRQ: %d\n",
+			       ret);
+			return ret;
+		}
+
+		ret = request_threaded_irq(max7360->intk, NULL, max7360_irqk,
+					  IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+					  "max7360", max7360);
+		if (ret) {
+			free_irq(max7360->inti, max7360);
+			dev_err(max7360->dev, "failed to request intk IRQ: %d\n",
+				ret);
+			return ret;
+		}
+	}
+
+	max7360->domain = irq_domain_add_simple(np, MAX7360_NR_INTERNAL_IRQS,
+					       0, &max7360_irq_ops, max7360);
+
+	if (!max7360->domain) {
+		if (max7360->shared_irq)
+			free_irq(max7360->shared_irq, max7360);
+		else {
+			free_irq(max7360->inti, max7360);
+			free_irq(max7360->intk, max7360);
+		}
+		dev_err(max7360->dev, "Failed to create irqdomain\n");
+		return -ENODEV;
+	}
+
+	irq_create_mapping(max7360->domain, MAX7360_INT_GPIO);
+	irq_create_mapping(max7360->domain, MAX7360_INT_KEYPAD);
+	irq_create_mapping(max7360->domain, MAX7360_INT_ROTARY);
+
+	return 0;
+}
+
+void max7360_fall_deepsleep(struct max7360 *max7360)
+{
+	max7360_write_reg(max7360, MAX7360_REG_SLEEP, MAX7360_AUTOSLEEP_8192);
+}
+EXPORT_SYMBOL_GPL(max7360_fall_deepsleep);
+
+void max7360_take_catnap(struct max7360 *max7360)
+{
+	max7360_write_reg(max7360, MAX7360_REG_SLEEP, MAX7360_AUTOSLEEP_256);
+}
+EXPORT_SYMBOL_GPL(max7360_take_catnap);
+
+static int max7360_chip_init(struct max7360 *max7360)
+{
+	max7360->gpio_pins = MAX7360_MAX_GPIO;
+	max7360->gpo_count = 0;
+	max7360->col_count = MAX7360_COL_GPO_PINS;
+	return 0;
+}
+
+static int max7360_device_init(struct max7360 *max7360)
+{
+	int ret = 0;
+
+	ret = mfd_add_devices(max7360->dev, -1, max7360_devices,
+			     ARRAY_SIZE(max7360_devices), NULL,
+			     0, max7360->domain);
+	if (ret)
+		dev_err(max7360->dev, "failed to add child devices\n");
+
+	return ret;
+}
+
+int max7360_request_gpo_pin_count(struct max7360 *max7360, u8 count)
+{
+	if (count > MAX7360_MAX_GPO)
+		return -EINVAL;
+	if (max7360->col_count + count > MAX7360_COL_GPO_PINS) {
+		dev_err(max7360->dev,
+		       "trying to request %d pins as gpo while %d pins already used as COL\n",
+		       count, max7360->col_count);
+		return -EINVAL;
+	}
+	max7360->gpo_count = count;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(max7360_request_gpo_pin_count);
+
+int max7360_request_col_count(struct max7360 *max7360, u8 count)
+{
+	if (max7360->gpo_count + count > MAX7360_COL_GPO_PINS) {
+		dev_err(max7360->dev,
+		       "trying to request %d pins as COL while %d pins already used as gpo\n",
+		       count, max7360->gpo_count);
+		return -EINVAL;
+	}
+	max7360->col_count = count;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(max7360_request_col_count);
+
+static const struct regmap_range max7360_volatile_ranges[] = {
+	{
+		.range_min = MAX7360_REG_KEYFIFO,
+		.range_max = MAX7360_REG_KEYFIFO,
+	}, {
+		.range_min = 0x48,
+		.range_max = 0x4a,
+	},
+};
+
+static const struct regmap_access_table max7360_volatile_table = {
+	.yes_ranges = max7360_volatile_ranges,
+	.n_yes_ranges = ARRAY_SIZE(max7360_volatile_ranges),
+};
+
+static const struct regmap_config max7360_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xff,
+	.volatile_table = &max7360_volatile_table,
+	.cache_type = REGCACHE_RBTREE,
+};
+
+static int max7360_probe(struct i2c_client *i2c,
+			const struct i2c_device_id *id)
+{
+	struct device_node *np = i2c->dev.of_node;
+	struct max7360 *max7360;
+
+	int ret;
+
+	max7360 = devm_kzalloc(&i2c->dev, sizeof(struct max7360),
+			      GFP_KERNEL);
+	if (!max7360)
+		return -ENOMEM;
+
+	spin_lock_init(&max7360->lock);
+
+	max7360->dev = &i2c->dev;
+	max7360->i2c = i2c;
+
+	i2c_set_clientdata(i2c, max7360);
+
+	max7360->regmap = devm_regmap_init_i2c(i2c, &max7360_regmap_config);
+	ret = max7360_chip_init(max7360);
+	if (ret)
+		return ret;
+
+	ret = max7360_irq_init(max7360, np);
+	if (ret)
+		return ret;
+
+	ret = max7360_device_init(max7360);
+	if (ret) {
+		dev_err(max7360->dev, "failed to add child devices\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int max7360_remove(struct i2c_client *client)
+{
+	struct max7360 *max7360 = i2c_get_clientdata(client);
+
+	mfd_remove_devices(max7360->dev);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int max7360_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int max7360_resume(struct device *dev)
+{
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(max7360_dev_pm_ops, max7360_suspend, max7360_resume);
+
+static const struct of_device_id max7360_match[] = {
+	{ .compatible = "maxim,max7360" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, max7360_match);
+
+static const struct i2c_device_id max7360_id[] = {
+	{ "max7360", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max7360_id);
+
+static struct i2c_driver max7360_driver = {
+	.driver = {
+		.name	= "max7360",
+		.pm	= &max7360_dev_pm_ops,
+		.of_match_table = max7360_match,
+	},
+	.probe		= max7360_probe,
+	.remove		= max7360_remove,
+	.id_table	= max7360_id,
+};
+
+static int __init max7360_init(void)
+{
+	return i2c_add_driver(&max7360_driver);
+}
+subsys_initcall(max7360_init);
+
+static void __exit max7360_exit(void)
+{
+	i2c_del_driver(&max7360_driver);
+}
+module_exit(max7360_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("MAX7360 MFD core driver");
diff --git a/include/linux/mfd/max7360.h b/include/linux/mfd/max7360.h
new file mode 100644
index 0000000..d139ddd
--- /dev/null
+++ b/include/linux/mfd/max7360.h
@@ -0,0 +1,130 @@
+#ifndef __LINUX_MFD_MAX7360_H
+#define __LINUX_MFD_MAX7360_H
+#include <linux/regmap.h>
+
+#define MAX7360_MAX_KEY_ROWS	8
+#define MAX7360_MAX_KEY_COLS	8
+#define MAX7360_MAX_KEY_NUM	(MAX7360_MAX_KEY_ROWS * MAX7360_MAX_KEY_COLS)
+#define MAX7360_ROW_SHIFT	3
+
+#define MAX7360_MAX_GPIO 8
+#define MAX7360_MAX_GPO 6
+#define MAX7360_COL_GPO_PINS 8
+/*
+ * MAX7360 registers
+ */
+#define MAX7360_REG_KEYFIFO	0x00
+#define MAX7360_REG_CONFIG	0x01
+#define MAX7360_REG_DEBOUNCE	0x02
+#define MAX7360_REG_INTERRUPT	0x03
+#define MAX7360_REG_PORTS	0x04
+#define MAX7360_REG_KEYREP	0x05
+#define MAX7360_REG_SLEEP	0x06
+
+/*
+ * MAX7360 registers
+ */
+#define MAX7360_REG_GPIOCFG	0x40
+#define MAX7360_REG_GPIOCTRL	0x41
+#define MAX7360_REG_GPIODEB	0x42
+#define MAX7360_REG_GPIOCURR	0x43
+#define MAX7360_REG_GPIOOUTM	0x44
+#define MAX7360_REG_PWMCOM	0x45
+#define MAX7360_REG_RTRCFG	0x46
+#define MAX7360_REG_GPIOIN	0x49
+#define MAX7360_REG_RTR_CNT	0x4A
+#define MAX7360_REG_PWMBASE	0x50
+#define MAX7360_REG_PWMCFG	0x58
+
+
+#define MAX7360_REG_PORTCFGBASE 0x58
+
+/*
+ * Configuration register bits
+ */
+#define MAX7360_CFG_SLEEP	(1 << 7)
+#define MAX7360_CFG_INTERRUPT	(1 << 5)
+#define MAX7360_CFG_KEY_RELEASE	(1 << 3)
+#define MAX7360_CFG_WAKEUP	(1 << 1)
+#define MAX7360_CFG_TIMEOUT	(1 << 0)
+
+/*
+ * Autosleep register values (ms)
+ */
+#define MAX7360_AUTOSLEEP_8192	0x01
+#define MAX7360_AUTOSLEEP_4096	0x02
+#define MAX7360_AUTOSLEEP_2048	0x03
+#define MAX7360_AUTOSLEEP_1024	0x04
+#define MAX7360_AUTOSLEEP_512	0x05
+#define MAX7360_AUTOSLEEP_256	0x06
+
+#define MAX7360_INT_INTI	0
+#define MAX7360_INT_INTK	1
+
+#define MAX7360_INT_GPIO   0
+#define MAX7360_INT_KEYPAD 1
+#define MAX7360_INT_ROTARY 2
+
+#define MAX7360_NR_INTERNAL_IRQS	3
+
+struct max7360 {
+	spinlock_t lock;		/* lock access to the structure */
+	struct device *dev;
+	struct i2c_client *i2c;
+	struct irq_domain *domain;
+	struct regmap *regmap;
+
+	int irq_base;
+	int num_gpio;
+	int shared_irq;
+	int inti;
+	int intk;
+	u8 gpio_pins;
+	u8 col_count;
+	u8 gpo_count;
+};
+
+static inline int max7360_read_reg(struct max7360 *max7360, int reg)
+{
+	unsigned int ival;
+	int ret;
+
+	ret = regmap_read(max7360->regmap, reg, &ival);
+	if (!ret)
+		return ival;
+	return 0;
+}
+
+static inline int max7360_write_reg(struct max7360 *max7360, u8 reg, u8 val)
+{
+	return regmap_write(max7360->regmap, reg, val);
+}
+
+static inline int max7360_set_bits(struct max7360 *max7360, u8 reg,
+				  unsigned int bit_mask)
+{
+	return regmap_update_bits(max7360->regmap, reg, bit_mask, bit_mask);
+}
+
+static inline int max7360_clr_bits(struct max7360 *max7360, u8 reg,
+				  unsigned int bit_mask)
+{
+	return regmap_update_bits(max7360->regmap, reg, bit_mask, 0);
+}
+
+static inline int max7360_update(struct max7360 *max7360, u8 reg, u8 val,
+				unsigned int bit_mask)
+{
+	return regmap_update_bits(max7360->regmap, reg, bit_mask, val);
+}
+
+int max7360_request_pin(struct max7360 *max7360, u8 pin);
+void max7360_free_pin(struct max7360 *max7360, u8 pin);
+
+void max7360_take_catnap(struct max7360 *max7360);
+void max7360_fall_deepsleep(struct max7360 *max7360);
+
+int max7360_request_gpo_pin_count(struct max7360 *max7360, u8 count);
+int max7360_request_col_count(struct max7360 *max7360, u8 count);
+
+#endif
-- 
2.9.3