mfd: Add lp8788 mfd driver

TI LP8788 PMU provides regulators, battery charger, ADC,
RTC, backlight driver and current sinks.

This MFD patch supports the I2C communication using the regmap,
the interrupt handling using the linear IRQ domain and
configurable platform data structures for each driver module.

 (Driver Architecture)

                                         < mfd devices >
  LP8788 HW  ..........  mfd  .......... regulator drivers
                I2C                      power supply driver
                IRQs                     iio adc driver
                                         rtc driver
                                         backlight driver
                                         current sink drivers

  o regulators    : LDOs and BUCKs
  o power supply  : Battery charger
  o iio adc       : Battery voltage/temperature
  o rtc           : RTC and alarm
  o backlight
  o current sink  : LED and vibrator

All MFD device modules are registered by LP8788 MFD core driver.
For sharing information such like the virtual IRQ number,
MFD core driver uses the resource structure.
Then each module can retrieve the specific IRQ number and detect it
in the IRQ thread.

Configurable platform data is handled in each driver module.

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

4 files changed, 455 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b9282cafa97..84d6ea2d74f 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -440,6 +440,16 @@ config PMIC_ADP5520
 	  individual components like LCD backlight, LEDs, GPIOs and Kepad
 	  under the corresponding menus.
 
+config MFD_LP8788
+	bool "Texas Instruments LP8788 Power Management Unit Driver"
+	depends on I2C=y
+	select MFD_CORE
+	select REGMAP_I2C
+	select IRQ_DOMAIN
+	help
+	  TI LP8788 PMU supports regulators, battery charger, RTC,
+	  ADC, backlight driver and current sinks.
+
 config MFD_MAX77686
 	bool "Maxim Semiconductor MAX77686 PMIC Support"
 	depends on I2C=y && GENERIC_HARDIRQS
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index d16bc0220e1..083acf97af2 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -89,6 +89,8 @@ obj-$(CONFIG_PMIC_DA9052)	+= da9052-core.o
 obj-$(CONFIG_MFD_DA9052_SPI)	+= da9052-spi.o
 obj-$(CONFIG_MFD_DA9052_I2C)	+= da9052-i2c.o
 
+obj-$(CONFIG_MFD_LP8788)	+= lp8788.o lp8788-irq.o
+
 obj-$(CONFIG_MFD_MAX77686)	+= max77686.o max77686-irq.o
 obj-$(CONFIG_MFD_MAX77693)	+= max77693.o max77693-irq.o
 obj-$(CONFIG_MFD_MAX8907)	+= max8907.o
diff --git a/drivers/mfd/lp8788-irq.c b/drivers/mfd/lp8788-irq.c
new file mode 100644
index 00000000000..c84ded5f8ec
--- /dev/null
+++ b/drivers/mfd/lp8788-irq.c
@@ -0,0 +1,198 @@
+/*
+ * TI LP8788 MFD - interrupt handler
+ *
+ * Copyright 2012 Texas Instruments
+ *
+ * Author: Milo(Woogyom) Kim <milo.kim@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.
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/device.h>
+#include <linux/mfd/lp8788.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+/* register address */
+#define LP8788_INT_1			0x00
+#define LP8788_INTEN_1			0x03
+
+#define BASE_INTEN_ADDR			LP8788_INTEN_1
+#define SIZE_REG			8
+#define NUM_REGS			3
+
+/*
+ * struct lp8788_irq_data
+ * @lp               : used for accessing to lp8788 registers
+ * @irq_lock         : mutex for enabling/disabling the interrupt
+ * @domain           : IRQ domain for handling nested interrupt
+ * @enabled          : status of enabled interrupt
+ */
+struct lp8788_irq_data {
+	struct lp8788 *lp;
+	struct mutex irq_lock;
+	struct irq_domain *domain;
+	int enabled[LP8788_INT_MAX];
+};
+
+static inline u8 _irq_to_addr(enum lp8788_int_id id)
+{
+	return id / SIZE_REG;
+}
+
+static inline u8 _irq_to_enable_addr(enum lp8788_int_id id)
+{
+	return _irq_to_addr(id) + BASE_INTEN_ADDR;
+}
+
+static inline u8 _irq_to_mask(enum lp8788_int_id id)
+{
+	return 1 << (id % SIZE_REG);
+}
+
+static inline u8 _irq_to_val(enum lp8788_int_id id, int enable)
+{
+	return enable << (id % SIZE_REG);
+}
+
+static void lp8788_irq_enable(struct irq_data *data)
+{
+	struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
+	irqd->enabled[data->hwirq] = 1;
+}
+
+static void lp8788_irq_disable(struct irq_data *data)
+{
+	struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
+	irqd->enabled[data->hwirq] = 0;
+}
+
+static void lp8788_irq_bus_lock(struct irq_data *data)
+{
+	struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
+
+	mutex_lock(&irqd->irq_lock);
+}
+
+static void lp8788_irq_bus_sync_unlock(struct irq_data *data)
+{
+	struct lp8788_irq_data *irqd = irq_data_get_irq_chip_data(data);
+	enum lp8788_int_id irq = data->hwirq;
+	u8 addr, mask, val;
+
+	addr = _irq_to_enable_addr(irq);
+	mask = _irq_to_mask(irq);
+	val = _irq_to_val(irq, irqd->enabled[irq]);
+
+	lp8788_update_bits(irqd->lp, addr, mask, val);
+
+	mutex_unlock(&irqd->irq_lock);
+}
+
+static struct irq_chip lp8788_irq_chip = {
+	.name			= "lp8788",
+	.irq_enable		= lp8788_irq_enable,
+	.irq_disable		= lp8788_irq_disable,
+	.irq_bus_lock		= lp8788_irq_bus_lock,
+	.irq_bus_sync_unlock	= lp8788_irq_bus_sync_unlock,
+};
+
+static irqreturn_t lp8788_irq_handler(int irq, void *ptr)
+{
+	struct lp8788_irq_data *irqd = ptr;
+	struct lp8788 *lp = irqd->lp;
+	u8 status[NUM_REGS], addr, mask;
+	bool handled;
+	int i;
+
+	if (lp8788_read_multi_bytes(lp, LP8788_INT_1, status, NUM_REGS))
+		return IRQ_NONE;
+
+	for (i = 0 ; i < LP8788_INT_MAX ; i++) {
+		addr = _irq_to_addr(i);
+		mask = _irq_to_mask(i);
+
+		/* reporting only if the irq is enabled */
+		if (status[addr] & mask) {
+			handle_nested_irq(irq_find_mapping(irqd->domain, i));
+			handled = true;
+		}
+	}
+
+	return handled ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int lp8788_irq_map(struct irq_domain *d, unsigned int virq,
+			irq_hw_number_t hwirq)
+{
+	struct lp8788_irq_data *irqd = d->host_data;
+	struct irq_chip *chip = &lp8788_irq_chip;
+
+	irq_set_chip_data(virq, irqd);
+	irq_set_chip_and_handler(virq, chip, handle_edge_irq);
+	irq_set_nested_thread(virq, 1);
+
+#ifdef CONFIG_ARM
+	set_irq_flags(virq, IRQF_VALID);
+#else
+	irq_set_noprobe(virq);
+#endif
+
+	return 0;
+}
+
+static struct irq_domain_ops lp8788_domain_ops = {
+	.map = lp8788_irq_map,
+};
+
+int lp8788_irq_init(struct lp8788 *lp, int irq)
+{
+	struct lp8788_irq_data *irqd;
+	int ret;
+
+	if (irq <= 0) {
+		dev_warn(lp->dev, "invalid irq number: %d\n", irq);
+		return 0;
+	}
+
+	irqd = devm_kzalloc(lp->dev, sizeof(*irqd), GFP_KERNEL);
+	if (!irqd)
+		return -ENOMEM;
+
+	irqd->lp = lp;
+	irqd->domain = irq_domain_add_linear(lp->dev->of_node, LP8788_INT_MAX,
+					&lp8788_domain_ops, irqd);
+	if (!irqd->domain) {
+		dev_err(lp->dev, "failed to add irq domain err\n");
+		return -EINVAL;
+	}
+
+	lp->irqdm = irqd->domain;
+	mutex_init(&irqd->irq_lock);
+
+	ret = request_threaded_irq(irq, NULL, lp8788_irq_handler,
+				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+				"lp8788-irq", irqd);
+	if (ret) {
+		dev_err(lp->dev, "failed to create a thread for IRQ_N\n");
+		return ret;
+	}
+
+	lp->irq = irq;
+
+	return 0;
+}
+
+void lp8788_irq_exit(struct lp8788 *lp)
+{
+	if (lp->irq)
+		free_irq(lp->irq, lp->irqdm);
+}
diff --git a/drivers/mfd/lp8788.c b/drivers/mfd/lp8788.c
new file mode 100644
index 00000000000..3e94a699833
--- /dev/null
+++ b/drivers/mfd/lp8788.c
@@ -0,0 +1,245 @@
+/*
+ * TI LP8788 MFD - core interface
+ *
+ * Copyright 2012 Texas Instruments
+ *
+ * Author: Milo(Woogyom) Kim <milo.kim@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.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/lp8788.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#define MAX_LP8788_REGISTERS		0xA2
+
+#define MFD_DEV_SIMPLE(_name)					\
+{								\
+	.name = LP8788_DEV_##_name,				\
+}
+
+#define MFD_DEV_WITH_ID(_name, _id)				\
+{								\
+	.name = LP8788_DEV_##_name,				\
+	.id = _id,						\
+}
+
+#define MFD_DEV_WITH_RESOURCE(_name, _resource, num_resource)	\
+{								\
+	.name = LP8788_DEV_##_name,				\
+	.resources = _resource,					\
+	.num_resources = num_resource,				\
+}
+
+static struct resource chg_irqs[] = {
+	/* Charger Interrupts */
+	{
+		.start = LP8788_INT_CHG_INPUT_STATE,
+		.end   = LP8788_INT_PRECHG_TIMEOUT,
+		.name  = LP8788_CHG_IRQ,
+		.flags = IORESOURCE_IRQ,
+	},
+	/* Power Routing Switch Interrupts */
+	{
+		.start = LP8788_INT_ENTER_SYS_SUPPORT,
+		.end   = LP8788_INT_EXIT_SYS_SUPPORT,
+		.name  = LP8788_PRSW_IRQ,
+		.flags = IORESOURCE_IRQ,
+	},
+	/* Battery Interrupts */
+	{
+		.start = LP8788_INT_BATT_LOW,
+		.end   = LP8788_INT_NO_BATT,
+		.name  = LP8788_BATT_IRQ,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource rtc_irqs[] = {
+	{
+		.start = LP8788_INT_RTC_ALARM1,
+		.end   = LP8788_INT_RTC_ALARM2,
+		.name  = LP8788_ALM_IRQ,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct mfd_cell lp8788_devs[] = {
+	/* 4 bucks */
+	MFD_DEV_WITH_ID(BUCK, 1),
+	MFD_DEV_WITH_ID(BUCK, 2),
+	MFD_DEV_WITH_ID(BUCK, 3),
+	MFD_DEV_WITH_ID(BUCK, 4),
+
+	/* 12 digital ldos */
+	MFD_DEV_WITH_ID(DLDO, 1),
+	MFD_DEV_WITH_ID(DLDO, 2),
+	MFD_DEV_WITH_ID(DLDO, 3),
+	MFD_DEV_WITH_ID(DLDO, 4),
+	MFD_DEV_WITH_ID(DLDO, 5),
+	MFD_DEV_WITH_ID(DLDO, 6),
+	MFD_DEV_WITH_ID(DLDO, 7),
+	MFD_DEV_WITH_ID(DLDO, 8),
+	MFD_DEV_WITH_ID(DLDO, 9),
+	MFD_DEV_WITH_ID(DLDO, 10),
+	MFD_DEV_WITH_ID(DLDO, 11),
+	MFD_DEV_WITH_ID(DLDO, 12),
+
+	/* 10 analog ldos */
+	MFD_DEV_WITH_ID(ALDO, 1),
+	MFD_DEV_WITH_ID(ALDO, 2),
+	MFD_DEV_WITH_ID(ALDO, 3),
+	MFD_DEV_WITH_ID(ALDO, 4),
+	MFD_DEV_WITH_ID(ALDO, 5),
+	MFD_DEV_WITH_ID(ALDO, 6),
+	MFD_DEV_WITH_ID(ALDO, 7),
+	MFD_DEV_WITH_ID(ALDO, 8),
+	MFD_DEV_WITH_ID(ALDO, 9),
+	MFD_DEV_WITH_ID(ALDO, 10),
+
+	/* ADC */
+	MFD_DEV_SIMPLE(ADC),
+
+	/* battery charger */
+	MFD_DEV_WITH_RESOURCE(CHARGER, chg_irqs, ARRAY_SIZE(chg_irqs)),
+
+	/* rtc */
+	MFD_DEV_WITH_RESOURCE(RTC, rtc_irqs, ARRAY_SIZE(rtc_irqs)),
+
+	/* backlight */
+	MFD_DEV_SIMPLE(BACKLIGHT),
+
+	/* current sink for vibrator */
+	MFD_DEV_SIMPLE(VIBRATOR),
+
+	/* current sink for keypad LED */
+	MFD_DEV_SIMPLE(KEYLED),
+};
+
+int lp8788_read_byte(struct lp8788 *lp, u8 reg, u8 *data)
+{
+	int ret;
+	unsigned int val;
+
+	ret = regmap_read(lp->regmap, reg, &val);
+	if (ret < 0) {
+		dev_err(lp->dev, "failed to read 0x%.2x\n", reg);
+		return ret;
+	}
+
+	*data = (u8)val;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(lp8788_read_byte);
+
+int lp8788_read_multi_bytes(struct lp8788 *lp, u8 reg, u8 *data, size_t count)
+{
+	return regmap_bulk_read(lp->regmap, reg, data, count);
+}
+EXPORT_SYMBOL_GPL(lp8788_read_multi_bytes);
+
+int lp8788_write_byte(struct lp8788 *lp, u8 reg, u8 data)
+{
+	return regmap_write(lp->regmap, reg, data);
+}
+EXPORT_SYMBOL_GPL(lp8788_write_byte);
+
+int lp8788_update_bits(struct lp8788 *lp, u8 reg, u8 mask, u8 data)
+{
+	return regmap_update_bits(lp->regmap, reg, mask, data);
+}
+EXPORT_SYMBOL_GPL(lp8788_update_bits);
+
+static int lp8788_platform_init(struct lp8788 *lp)
+{
+	struct lp8788_platform_data *pdata = lp->pdata;
+
+	return (pdata && pdata->init_func) ? pdata->init_func(lp) : 0;
+}
+
+static const struct regmap_config lp8788_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = MAX_LP8788_REGISTERS,
+};
+
+static int lp8788_probe(struct i2c_client *cl, const struct i2c_device_id *id)
+{
+	struct lp8788 *lp;
+	struct lp8788_platform_data *pdata = cl->dev.platform_data;
+	int ret;
+
+	lp = devm_kzalloc(&cl->dev, sizeof(struct lp8788), GFP_KERNEL);
+	if (!lp)
+		return -ENOMEM;
+
+	lp->regmap = devm_regmap_init_i2c(cl, &lp8788_regmap_config);
+	if (IS_ERR(lp->regmap)) {
+		ret = PTR_ERR(lp->regmap);
+		dev_err(&cl->dev, "regmap init i2c err: %d\n", ret);
+		return ret;
+	}
+
+	lp->pdata = pdata;
+	lp->dev = &cl->dev;
+	i2c_set_clientdata(cl, lp);
+
+	ret = lp8788_platform_init(lp);
+	if (ret)
+		return ret;
+
+	ret = lp8788_irq_init(lp, cl->irq);
+	if (ret)
+		return ret;
+
+	return mfd_add_devices(lp->dev, -1, lp8788_devs,
+			       ARRAY_SIZE(lp8788_devs), NULL, 0, NULL);
+}
+
+static int __devexit lp8788_remove(struct i2c_client *cl)
+{
+	struct lp8788 *lp = i2c_get_clientdata(cl);
+
+	mfd_remove_devices(lp->dev);
+	lp8788_irq_exit(lp);
+	return 0;
+}
+
+static const struct i2c_device_id lp8788_ids[] = {
+	{"lp8788", 0},
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, lp8788_ids);
+
+static struct i2c_driver lp8788_driver = {
+	.driver = {
+		.name = "lp8788",
+		.owner = THIS_MODULE,
+	},
+	.probe = lp8788_probe,
+	.remove = __devexit_p(lp8788_remove),
+	.id_table = lp8788_ids,
+};
+
+static int __init lp8788_init(void)
+{
+	return i2c_add_driver(&lp8788_driver);
+}
+subsys_initcall(lp8788_init);
+
+static void __exit lp8788_exit(void)
+{
+	i2c_del_driver(&lp8788_driver);
+}
+module_exit(lp8788_exit);
+
+MODULE_DESCRIPTION("TI LP8788 MFD Driver");
+MODULE_AUTHOR("Milo Kim");
+MODULE_LICENSE("GPL");