mfd: AB3550 core driver

This adds a core driver for the AB3550 mixed-signal circuit
found in the ST-Ericsson U300 platforms. This driver
is a singleton proxy for all access to the AB3550 sub
functionality drivers which can be added on top of this one:
RTC, regulators, battery and system power control, vibrator,
LEDs and an ALSA codec.

Signed-off-by: Mattias Wallin <mattias.wallin@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

3 files changed, 1416 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 1c3d737ec406..a20fa230d354 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -423,6 +423,20 @@ config AB4500_CORE
 	  read/write functions for the devices to get access to this chip.
 	  This chip embeds various other multimedia funtionalities as well.
 
+config AB3550_CORE
+        bool "ST-Ericsson AB3550 Mixed Signal Circuit core functions"
+	select MFD_CORE
+	depends on I2C=y && GENERIC_HARDIRQS && ABX500_CORE
+	help
+	  Select this to enable the AB3550 Mixed Signal IC core
+	  functionality. This connects to a AB3550 on the I2C bus
+	  and expose a number of symbols needed for dependent devices
+	  to read and write registers and subscribe to events from
+	  this multi-functional IC. This is needed to use other features
+	  of the AB3550 such as battery-backed RTC, charging control,
+	  LEDs, vibrator, system power and temperature, power management
+	  and ALSA sound.
+
 config MFD_TIMBERDALE
 	tristate "Support for the Timberdale FPGA"
 	select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 4b8ad04ff8e2..4c684c137d43 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -64,6 +64,7 @@ obj-$(CONFIG_ABX500_CORE)	+= abx500-core.o
 obj-$(CONFIG_AB3100_CORE)	+= ab3100-core.o
 obj-$(CONFIG_AB3100_OTP)	+= ab3100-otp.o
 obj-$(CONFIG_AB4500_CORE)	+= ab4500-core.o
+obj-$(CONFIG_AB3550_CORE)	+= ab3550-core.o
 obj-$(CONFIG_MFD_TIMBERDALE)    += timberdale.o
 obj-$(CONFIG_PMIC_ADP5520)	+= adp5520.o
 obj-$(CONFIG_LPC_SCH)		+= lpc_sch.o
diff --git a/drivers/mfd/ab3550-core.c b/drivers/mfd/ab3550-core.c
new file mode 100644
index 000000000000..1060f8e1c40a
--- /dev/null
+++ b/drivers/mfd/ab3550-core.c
@@ -0,0 +1,1401 @@
+/*
+ * Copyright (C) 2007-2010 ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ * Low-level core for exclusive access to the AB3550 IC on the I2C bus
+ * and some basic chip-configuration.
+ * Author: Bengt Jonsson <bengt.g.jonsson@stericsson.com>
+ * Author: Mattias Nilsson <mattias.i.nilsson@stericsson.com>
+ * Author: Mattias Wallin <mattias.wallin@stericsson.com>
+ * Author: Rickard Andersson <rickard.andersson@stericsson.com>
+ */
+
+#include <linux/i2c.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/random.h>
+#include <linux/workqueue.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+#include <linux/mfd/abx500.h>
+#include <linux/list.h>
+#include <linux/bitops.h>
+#include <linux/spinlock.h>
+#include <linux/mfd/core.h>
+
+#define AB3550_NAME_STRING "ab3550"
+#define AB3550_ID_FORMAT_STRING "AB3550 %s"
+#define AB3550_NUM_BANKS 2
+#define AB3550_NUM_EVENT_REG 5
+
+/* These are the only registers inside AB3550 used in this main file */
+
+/* Chip ID register */
+#define AB3550_CID_REG           0x20
+
+/* Interrupt event registers */
+#define AB3550_EVENT_BANK        0
+#define AB3550_EVENT_REG         0x22
+
+/* Read/write operation values. */
+#define AB3550_PERM_RD (0x01)
+#define AB3550_PERM_WR (0x02)
+
+/* Read/write permissions. */
+#define AB3550_PERM_RO (AB3550_PERM_RD)
+#define AB3550_PERM_RW (AB3550_PERM_RD | AB3550_PERM_WR)
+
+/**
+ * struct ab3550
+ * @access_mutex: lock out concurrent accesses to the AB registers
+ * @i2c_client: I2C client for this chip
+ * @chip_name: name of this chip variant
+ * @chip_id: 8 bit chip ID for this chip variant
+ * @mask_work: a worker for writing to mask registers
+ * @event_lock: a lock to protect the event_mask
+ * @event_mask: a local copy of the mask event registers
+ * @startup_events: a copy of the first reading of the event registers
+ * @startup_events_read: whether the first events have been read
+ */
+struct ab3550 {
+	struct mutex access_mutex;
+	struct i2c_client *i2c_client[AB3550_NUM_BANKS];
+	char chip_name[32];
+	u8 chip_id;
+	struct work_struct mask_work;
+	spinlock_t event_lock;
+	u8 event_mask[AB3550_NUM_EVENT_REG];
+	u8 startup_events[AB3550_NUM_EVENT_REG];
+	bool startup_events_read;
+#ifdef CONFIG_DEBUG_FS
+	unsigned int debug_bank;
+	unsigned int debug_address;
+#endif
+};
+
+/**
+ * struct ab3550_reg_range
+ * @first: the first address of the range
+ * @last: the last address of the range
+ * @perm: access permissions for the range
+ */
+struct ab3550_reg_range {
+	u8 first;
+	u8 last;
+	u8 perm;
+};
+
+/**
+ * struct ab3550_reg_ranges
+ * @count: the number of ranges in the list
+ * @range: the list of register ranges
+ */
+struct ab3550_reg_ranges {
+	u8 count;
+	const struct ab3550_reg_range *range;
+};
+
+/*
+ * Permissible register ranges for reading and writing per device and bank.
+ *
+ * The ranges must be listed in increasing address order, and no overlaps are
+ * allowed. It is assumed that write permission implies read permission
+ * (i.e. only RO and RW permissions should be used).  Ranges with write
+ * permission must not be split up.
+ */
+
+#define NO_RANGE {.count = 0, .range = NULL,}
+
+static struct
+ab3550_reg_ranges ab3550_reg_ranges[AB3550_NUM_DEVICES][AB3550_NUM_BANKS] = {
+	[AB3550_DEVID_DAC] = {
+		NO_RANGE,
+		{
+			.count = 2,
+			.range = (struct ab3550_reg_range[]) {
+				{
+					.first = 0xb0,
+					.last = 0xba,
+					.perm = AB3550_PERM_RW,
+				},
+				{
+					.first = 0xbc,
+					.last = 0xc3,
+					.perm = AB3550_PERM_RW,
+				},
+			},
+		},
+	},
+	[AB3550_DEVID_LEDS] = {
+		NO_RANGE,
+		{
+			.count = 2,
+			.range = (struct ab3550_reg_range[]) {
+				{
+					.first = 0x5a,
+					.last = 0x88,
+					.perm = AB3550_PERM_RW,
+				},
+				{
+					.first = 0x8a,
+					.last = 0xad,
+					.perm = AB3550_PERM_RW,
+				},
+			}
+		},
+	},
+	[AB3550_DEVID_POWER] = {
+		{
+			.count = 1,
+			.range = (struct ab3550_reg_range[]) {
+				{
+					.first = 0x21,
+					.last = 0x21,
+					.perm = AB3550_PERM_RO,
+				},
+			}
+		},
+		NO_RANGE,
+	},
+	[AB3550_DEVID_REGULATORS] = {
+		{
+			.count = 1,
+			.range = (struct ab3550_reg_range[]) {
+				{
+					.first = 0x69,
+					.last = 0xa3,
+					.perm = AB3550_PERM_RW,
+				},
+			}
+		},
+		{
+			.count = 1,
+			.range = (struct ab3550_reg_range[]) {
+				{
+					.first = 0x14,
+					.last = 0x16,
+					.perm = AB3550_PERM_RW,
+				},
+			}
+		},
+	},
+	[AB3550_DEVID_SIM] = {
+		{
+			.count = 1,
+			.range = (struct ab3550_reg_range[]) {
+				{
+					.first = 0x21,
+					.last = 0x21,
+					.perm = AB3550_PERM_RO,
+				},
+			}
+		},
+		{
+			.count = 1,
+			.range = (struct ab3550_reg_range[]) {
+				{
+					.first = 0x14,
+					.last = 0x17,
+					.perm = AB3550_PERM_RW,
+				},
+			}
+
+		},
+	},
+	[AB3550_DEVID_UART] = {
+		NO_RANGE,
+		NO_RANGE,
+	},
+	[AB3550_DEVID_RTC] = {
+		{
+			.count = 1,
+			.range = (struct ab3550_reg_range[]) {
+				{
+					.first = 0x00,
+					.last = 0x0c,
+					.perm = AB3550_PERM_RW,
+				},
+			}
+		},
+		NO_RANGE,
+	},
+	[AB3550_DEVID_CHARGER] = {
+		{
+			.count = 2,
+			.range = (struct ab3550_reg_range[]) {
+				{
+					.first = 0x10,
+					.last = 0x1a,
+					.perm = AB3550_PERM_RW,
+				},
+				{
+					.first = 0x21,
+					.last = 0x21,
+					.perm = AB3550_PERM_RO,
+				},
+			}
+		},
+		NO_RANGE,
+	},
+	[AB3550_DEVID_ADC] = {
+		NO_RANGE,
+		{
+			.count = 1,
+			.range = (struct ab3550_reg_range[]) {
+				{
+					.first = 0x20,
+					.last = 0x56,
+					.perm = AB3550_PERM_RW,
+				},
+
+			}
+		},
+	},
+	[AB3550_DEVID_FUELGAUGE] = {
+		{
+			.count = 1,
+			.range = (struct ab3550_reg_range[]) {
+				{
+					.first = 0x21,
+					.last = 0x21,
+					.perm = AB3550_PERM_RO,
+				},
+			}
+		},
+		{
+			.count = 1,
+			.range = (struct ab3550_reg_range[]) {
+				{
+					.first = 0x00,
+					.last = 0x0e,
+					.perm = AB3550_PERM_RW,
+				},
+			}
+		},
+	},
+	[AB3550_DEVID_VIBRATOR] = {
+		NO_RANGE,
+		{
+			.count = 1,
+			.range = (struct ab3550_reg_range[]) {
+				{
+					.first = 0x10,
+					.last = 0x13,
+					.perm = AB3550_PERM_RW,
+				},
+
+			}
+		},
+	},
+	[AB3550_DEVID_CODEC] = {
+		{
+			.count = 2,
+			.range = (struct ab3550_reg_range[]) {
+				{
+					.first = 0x31,
+					.last = 0x63,
+					.perm = AB3550_PERM_RW,
+				},
+				{
+					.first = 0x65,
+					.last = 0x68,
+					.perm = AB3550_PERM_RW,
+				},
+			}
+		},
+		NO_RANGE,
+	},
+};
+
+static struct mfd_cell ab3550_devs[AB3550_NUM_DEVICES] = {
+	[AB3550_DEVID_DAC] = {
+		.name = "ab3550-dac",
+		.id = AB3550_DEVID_DAC,
+		.num_resources = 0,
+	},
+	[AB3550_DEVID_LEDS] = {
+		.name = "ab3550-leds",
+		.id = AB3550_DEVID_LEDS,
+	},
+	[AB3550_DEVID_POWER] = {
+		.name = "ab3550-power",
+		.id = AB3550_DEVID_POWER,
+	},
+	[AB3550_DEVID_REGULATORS] = {
+		.name = "ab3550-regulators",
+		.id = AB3550_DEVID_REGULATORS,
+	},
+	[AB3550_DEVID_SIM] = {
+		.name = "ab3550-sim",
+		.id = AB3550_DEVID_SIM,
+	},
+	[AB3550_DEVID_UART] = {
+		.name = "ab3550-uart",
+		.id = AB3550_DEVID_UART,
+	},
+	[AB3550_DEVID_RTC] = {
+		.name = "ab3550-rtc",
+		.id = AB3550_DEVID_RTC,
+	},
+	[AB3550_DEVID_CHARGER] = {
+		.name = "ab3550-charger",
+		.id = AB3550_DEVID_CHARGER,
+	},
+	[AB3550_DEVID_ADC] = {
+		.name = "ab3550-adc",
+		.id = AB3550_DEVID_ADC,
+		.num_resources = 10,
+		.resources = (struct resource[]) {
+			{
+				.name = "TRIGGER-0",
+				.flags = IORESOURCE_IRQ,
+				.start = 16,
+				.end = 16,
+			},
+			{
+				.name = "TRIGGER-1",
+				.flags = IORESOURCE_IRQ,
+				.start = 17,
+				.end = 17,
+			},
+			{
+				.name = "TRIGGER-2",
+				.flags = IORESOURCE_IRQ,
+				.start = 18,
+				.end = 18,
+			},
+			{
+				.name = "TRIGGER-3",
+				.flags = IORESOURCE_IRQ,
+				.start = 19,
+				.end = 19,
+			},
+			{
+				.name = "TRIGGER-4",
+				.flags = IORESOURCE_IRQ,
+				.start = 20,
+				.end = 20,
+			},
+			{
+				.name = "TRIGGER-5",
+				.flags = IORESOURCE_IRQ,
+				.start = 21,
+				.end = 21,
+			},
+			{
+				.name = "TRIGGER-6",
+				.flags = IORESOURCE_IRQ,
+				.start = 22,
+				.end = 22,
+			},
+			{
+				.name = "TRIGGER-7",
+				.flags = IORESOURCE_IRQ,
+				.start = 23,
+				.end = 23,
+			},
+			{
+				.name = "TRIGGER-VBAT-TXON",
+				.flags = IORESOURCE_IRQ,
+				.start = 13,
+				.end = 13,
+			},
+			{
+				.name = "TRIGGER-VBAT",
+				.flags = IORESOURCE_IRQ,
+				.start = 12,
+				.end = 12,
+			},
+		},
+	},
+	[AB3550_DEVID_FUELGAUGE] = {
+		.name = "ab3550-fuelgauge",
+		.id = AB3550_DEVID_FUELGAUGE,
+	},
+	[AB3550_DEVID_VIBRATOR] = {
+		.name = "ab3550-vibrator",
+		.id = AB3550_DEVID_VIBRATOR,
+	},
+	[AB3550_DEVID_CODEC] = {
+		.name = "ab3550-codec",
+		.id = AB3550_DEVID_CODEC,
+	},
+};
+
+/*
+ * I2C transactions with error messages.
+ */
+static int ab3550_i2c_master_send(struct ab3550 *ab, u8 bank, u8 *data,
+	u8 count)
+{
+	int err;
+
+	err = i2c_master_send(ab->i2c_client[bank], data, count);
+	if (err < 0) {
+		dev_err(&ab->i2c_client[0]->dev, "send error: %d\n", err);
+		return err;
+	}
+	return 0;
+}
+
+static int ab3550_i2c_master_recv(struct ab3550 *ab, u8 bank, u8 *data,
+	u8 count)
+{
+	int err;
+
+	err = i2c_master_recv(ab->i2c_client[bank], data, count);
+	if (err < 0) {
+		dev_err(&ab->i2c_client[0]->dev, "receive error: %d\n", err);
+		return err;
+	}
+	return 0;
+}
+
+/*
+ * Functionality for getting/setting register values.
+ */
+static int get_register_interruptible(struct ab3550 *ab, u8 bank, u8 reg,
+	u8 *value)
+{
+	int err;
+
+	err = mutex_lock_interruptible(&ab->access_mutex);
+	if (err)
+		return err;
+
+	err = ab3550_i2c_master_send(ab, bank, &reg, 1);
+	if (!err)
+		err = ab3550_i2c_master_recv(ab, bank, value, 1);
+
+	mutex_unlock(&ab->access_mutex);
+	return err;
+}
+
+static int get_register_page_interruptible(struct ab3550 *ab, u8 bank,
+	u8 first_reg, u8 *regvals, u8 numregs)
+{
+	int err;
+
+	err = mutex_lock_interruptible(&ab->access_mutex);
+	if (err)
+		return err;
+
+	err = ab3550_i2c_master_send(ab, bank, &first_reg, 1);
+	if (!err)
+		err = ab3550_i2c_master_recv(ab, bank, regvals, numregs);
+
+	mutex_unlock(&ab->access_mutex);
+	return err;
+}
+
+static int mask_and_set_register_interruptible(struct ab3550 *ab, u8 bank,
+	u8 reg, u8 bitmask, u8 bitvalues)
+{
+	int err = 0;
+
+	if (likely(bitmask)) {
+		u8 reg_bits[2] = {reg, 0};
+
+		err = mutex_lock_interruptible(&ab->access_mutex);
+		if (err)
+			return err;
+
+		if (bitmask == 0xFF) /* No need to read in this case. */
+			reg_bits[1] = bitvalues;
+		else { /* Read and modify the register value. */
+			u8 bits;
+
+			err = ab3550_i2c_master_send(ab, bank, &reg, 1);
+			if (err)
+				goto unlock_and_return;
+			err = ab3550_i2c_master_recv(ab, bank, &bits, 1);
+			if (err)
+				goto unlock_and_return;
+			reg_bits[1] = ((~bitmask & bits) |
+				(bitmask & bitvalues));
+		}
+		/* Write the new value. */
+		err = ab3550_i2c_master_send(ab, bank, reg_bits, 2);
+unlock_and_return:
+		mutex_unlock(&ab->access_mutex);
+	}
+	return err;
+}
+
+/*
+ * Read/write permission checking functions.
+ */
+static bool page_write_allowed(const struct ab3550_reg_ranges *ranges,
+	u8 first_reg, u8 last_reg)
+{
+	u8 i;
+
+	if (last_reg < first_reg)
+		return false;
+
+	for (i = 0; i < ranges->count; i++) {
+		if (first_reg < ranges->range[i].first)
+			break;
+		if ((last_reg <= ranges->range[i].last) &&
+			(ranges->range[i].perm & AB3550_PERM_WR))
+			return true;
+	}
+	return false;
+}
+
+static bool reg_write_allowed(const struct ab3550_reg_ranges *ranges, u8 reg)
+{
+	return page_write_allowed(ranges, reg, reg);
+}
+
+static bool page_read_allowed(const struct ab3550_reg_ranges *ranges,
+	u8 first_reg, u8 last_reg)
+{
+	u8 i;
+
+	if (last_reg < first_reg)
+		return false;
+	/* Find the range (if it exists in the list) that includes first_reg. */
+	for (i = 0; i < ranges->count; i++) {
+		if (first_reg < ranges->range[i].first)
+			return false;
+		if (first_reg <= ranges->range[i].last)
+			break;
+	}
+	/* Make sure that the entire range up to and including last_reg is
+	 * readable. This may span several of the ranges in the list.
+	 */
+	while ((i < ranges->count) &&
+		(ranges->range[i].perm & AB3550_PERM_RD)) {
+		if (last_reg <= ranges->range[i].last)
+			return true;
+		if ((++i >= ranges->count) ||
+			(ranges->range[i].first !=
+			 (ranges->range[i - 1].last + 1))) {
+			break;
+		}
+	}
+	return false;
+}
+
+static bool reg_read_allowed(const struct ab3550_reg_ranges *ranges, u8 reg)
+{
+	return page_read_allowed(ranges, reg, reg);
+}
+
+/*
+ * The exported register access functionality.
+ */
+int ab3550_get_chip_id(struct device *dev)
+{
+	struct ab3550 *ab = dev_get_drvdata(dev->parent);
+	return (int)ab->chip_id;
+}
+
+int ab3550_mask_and_set_register_interruptible(struct device *dev, u8 bank,
+	u8 reg, u8 bitmask, u8 bitvalues)
+{
+	struct ab3550 *ab;
+	struct platform_device *pdev = to_platform_device(dev);
+
+	if ((AB3550_NUM_BANKS <= bank) ||
+		!reg_write_allowed(&ab3550_reg_ranges[pdev->id][bank], reg))
+		return -EINVAL;
+
+	ab = dev_get_drvdata(dev->parent);
+	return mask_and_set_register_interruptible(ab, bank, reg,
+		bitmask, bitvalues);
+}
+
+int ab3550_set_register_interruptible(struct device *dev, u8 bank, u8 reg,
+	u8 value)
+{
+	return ab3550_mask_and_set_register_interruptible(dev, bank, reg, 0xFF,
+		value);
+}
+
+int ab3550_get_register_interruptible(struct device *dev, u8 bank, u8 reg,
+	u8 *value)
+{
+	struct ab3550 *ab;
+	struct platform_device *pdev = to_platform_device(dev);
+
+	if ((AB3550_NUM_BANKS <= bank) ||
+		!reg_read_allowed(&ab3550_reg_ranges[pdev->id][bank], reg))
+		return -EINVAL;
+
+	ab = dev_get_drvdata(dev->parent);
+	return get_register_interruptible(ab, bank, reg, value);
+}
+
+int ab3550_get_register_page_interruptible(struct device *dev, u8 bank,
+	u8 first_reg, u8 *regvals, u8 numregs)
+{
+	struct ab3550 *ab;
+	struct platform_device *pdev = to_platform_device(dev);
+
+	if ((AB3550_NUM_BANKS <= bank) ||
+		!page_read_allowed(&ab3550_reg_ranges[pdev->id][bank],
+			first_reg, (first_reg + numregs - 1)))
+		return -EINVAL;
+
+	ab = dev_get_drvdata(dev->parent);
+	return get_register_page_interruptible(ab, bank, first_reg, regvals,
+		numregs);
+}
+
+int ab3550_event_registers_startup_state_get(struct device *dev, u8 *event)
+{
+	struct ab3550 *ab;
+
+	ab = dev_get_drvdata(dev->parent);
+	if (!ab->startup_events_read)
+		return -EAGAIN; /* Try again later */
+
+	memcpy(event, ab->startup_events, AB3550_NUM_EVENT_REG);
+	return 0;
+}
+
+int ab3550_startup_irq_enabled(struct device *dev, unsigned int irq)
+{
+	struct ab3550 *ab;
+	struct ab3550_platform_data *plf_data;
+	bool val;
+
+	ab = get_irq_chip_data(irq);
+	plf_data = ab->i2c_client[0]->dev.platform_data;
+	irq -= plf_data->irq.base;
+	val = ((ab->startup_events[irq / 8] & BIT(irq % 8)) != 0);
+
+	return val;
+}
+
+static struct abx500_ops ab3550_ops = {
+	.get_chip_id = ab3550_get_chip_id,
+	.get_register = ab3550_get_register_interruptible,
+	.set_register = ab3550_set_register_interruptible,
+	.get_register_page = ab3550_get_register_page_interruptible,
+	.set_register_page = NULL,
+	.mask_and_set_register = ab3550_mask_and_set_register_interruptible,
+	.event_registers_startup_state_get =
+		ab3550_event_registers_startup_state_get,
+	.startup_irq_enabled = ab3550_startup_irq_enabled,
+};
+
+static irqreturn_t ab3550_irq_handler(int irq, void *data)
+{
+	struct ab3550 *ab = data;
+	int err;
+	unsigned int i;
+	u8 e[AB3550_NUM_EVENT_REG];
+	u8 *events;
+	unsigned long flags;
+
+	events = (ab->startup_events_read ? e : ab->startup_events);
+
+	err = get_register_page_interruptible(ab, AB3550_EVENT_BANK,
+		AB3550_EVENT_REG, events, AB3550_NUM_EVENT_REG);
+	if (err)
+		goto err_event_rd;
+
+	if (!ab->startup_events_read) {
+		dev_info(&ab->i2c_client[0]->dev,
+			"startup events 0x%x,0x%x,0x%x,0x%x,0x%x\n",
+			ab->startup_events[0], ab->startup_events[1],
+			ab->startup_events[2], ab->startup_events[3],
+			ab->startup_events[4]);
+		ab->startup_events_read = true;
+		goto out;
+	}
+
+	/* The two highest bits in event[4] are not used. */
+	events[4] &= 0x3f;
+
+	spin_lock_irqsave(&ab->event_lock, flags);
+	for (i = 0; i < AB3550_NUM_EVENT_REG; i++)
+		events[i] &= ~ab->event_mask[i];
+	spin_unlock_irqrestore(&ab->event_lock, flags);
+
+	for (i = 0; i < AB3550_NUM_EVENT_REG; i++) {
+		u8 bit;
+		u8 event_reg;
+
+		dev_dbg(&ab->i2c_client[0]->dev, "IRQ Event[%d]: 0x%2x\n",
+			i, events[i]);
+
+		event_reg = events[i];
+		for (bit = 0; event_reg; bit++, event_reg /= 2) {
+			if (event_reg % 2) {
+				unsigned int irq;
+				struct ab3550_platform_data *plf_data;
+
+				plf_data = ab->i2c_client[0]->dev.platform_data;
+				irq = plf_data->irq.base + (i * 8) + bit;
+				handle_nested_irq(irq);
+			}
+		}
+	}
+out:
+	return IRQ_HANDLED;
+
+err_event_rd:
+	dev_dbg(&ab->i2c_client[0]->dev, "error reading event registers\n");
+	return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_DEBUG_FS
+static struct ab3550_reg_ranges debug_ranges[AB3550_NUM_BANKS] = {
+	{
+		.count = 6,
+		.range = (struct ab3550_reg_range[]) {
+			{
+				.first = 0x00,
+				.last = 0x0e,
+			},
+			{
+				.first = 0x10,
+				.last = 0x1a,
+			},
+			{
+				.first = 0x1e,
+				.last = 0x4f,
+			},
+			{
+				.first = 0x51,
+				.last = 0x63,
+			},
+			{
+				.first = 0x65,
+				.last = 0xa3,
+			},
+			{
+				.first = 0xa5,
+				.last = 0xa8,
+			},
+		}
+	},
+	{
+		.count = 8,
+		.range = (struct ab3550_reg_range[]) {
+			{
+				.first = 0x00,
+				.last = 0x0e,
+			},
+			{
+				.first = 0x10,
+				.last = 0x17,
+			},
+			{
+				.first = 0x1a,
+				.last = 0x1c,
+			},
+			{
+				.first = 0x20,
+				.last = 0x56,
+			},
+			{
+				.first = 0x5a,
+				.last = 0x88,
+			},
+			{
+				.first = 0x8a,
+				.last = 0xad,
+			},
+			{
+				.first = 0xb0,
+				.last = 0xba,
+			},
+			{
+				.first = 0xbc,
+				.last = 0xc3,
+			},
+		}
+	},
+};
+
+static int ab3550_registers_print(struct seq_file *s, void *p)
+{
+	struct ab3550 *ab = s->private;
+	int bank;
+
+	seq_printf(s, AB3550_NAME_STRING " register values:\n");
+
+	for (bank = 0; bank < AB3550_NUM_BANKS; bank++) {
+		unsigned int i;
+
+		seq_printf(s, " bank %d:\n", bank);
+		for (i = 0; i < debug_ranges[bank].count; i++) {
+			u8 reg;
+
+			for (reg = debug_ranges[bank].range[i].first;
+				reg <= debug_ranges[bank].range[i].last;
+				reg++) {
+				u8 value;
+
+				get_register_interruptible(ab, bank, reg,
+					&value);
+				seq_printf(s, "  [%d/0x%02X]: 0x%02X\n", bank,
+					reg, value);
+			}
+		}
+	}
+	return 0;
+}
+
+static int ab3550_registers_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, ab3550_registers_print, inode->i_private);
+}
+
+static const struct file_operations ab3550_registers_fops = {
+	.open = ab3550_registers_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+	.owner = THIS_MODULE,
+};
+
+static int ab3550_bank_print(struct seq_file *s, void *p)
+{
+	struct ab3550 *ab = s->private;
+
+	seq_printf(s, "%d\n", ab->debug_bank);
+	return 0;
+}
+
+static int ab3550_bank_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, ab3550_bank_print, inode->i_private);
+}
+
+static ssize_t ab3550_bank_write(struct file *file,
+	const char __user *user_buf,
+	size_t count, loff_t *ppos)
+{
+	struct ab3550 *ab = ((struct seq_file *)(file->private_data))->private;
+	char buf[32];
+	int buf_size;
+	unsigned long user_bank;
+	int err;
+
+	/* Get userspace string and assure termination */
+	buf_size = min(count, (sizeof(buf) - 1));
+	if (copy_from_user(buf, user_buf, buf_size))
+		return -EFAULT;
+	buf[buf_size] = 0;
+
+	err = strict_strtoul(buf, 0, &user_bank);
+	if (err)
+		return -EINVAL;
+
+	if (user_bank >= AB3550_NUM_BANKS) {
+		dev_err(&ab->i2c_client[0]->dev,
+			"debugfs error input > number of banks\n");
+		return -EINVAL;
+	}
+
+	ab->debug_bank = user_bank;
+
+	return buf_size;
+}
+
+static int ab3550_address_print(struct seq_file *s, void *p)
+{
+	struct ab3550 *ab = s->private;
+
+	seq_printf(s, "0x%02X\n", ab->debug_address);
+	return 0;
+}
+
+static int ab3550_address_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, ab3550_address_print, inode->i_private);
+}
+
+static ssize_t ab3550_address_write(struct file *file,
+	const char __user *user_buf,
+	size_t count, loff_t *ppos)
+{
+	struct ab3550 *ab = ((struct seq_file *)(file->private_data))->private;
+	char buf[32];
+	int buf_size;
+	unsigned long user_address;
+	int err;
+
+	/* Get userspace string and assure termination */
+	buf_size = min(count, (sizeof(buf) - 1));
+	if (copy_from_user(buf, user_buf, buf_size))
+		return -EFAULT;
+	buf[buf_size] = 0;
+
+	err = strict_strtoul(buf, 0, &user_address);
+	if (err)
+		return -EINVAL;
+	if (user_address > 0xff) {
+		dev_err(&ab->i2c_client[0]->dev,
+			"debugfs error input > 0xff\n");
+		return -EINVAL;
+	}
+	ab->debug_address = user_address;
+	return buf_size;
+}
+
+static int ab3550_val_print(struct seq_file *s, void *p)
+{
+	struct ab3550 *ab = s->private;
+	int err;
+	u8 regvalue;
+
+	err = get_register_interruptible(ab, (u8)ab->debug_bank,
+		(u8)ab->debug_address, &regvalue);
+	if (err)
+		return -EINVAL;
+	seq_printf(s, "0x%02X\n", regvalue);
+
+	return 0;
+}
+
+static int ab3550_val_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, ab3550_val_print, inode->i_private);
+}
+
+static ssize_t ab3550_val_write(struct file *file,
+	const char __user *user_buf,
+	size_t count, loff_t *ppos)
+{
+	struct ab3550 *ab = ((struct seq_file *)(file->private_data))->private;
+	char buf[32];
+	int buf_size;
+	unsigned long user_val;
+	int err;
+	u8 regvalue;
+
+	/* Get userspace string and assure termination */
+	buf_size = min(count, (sizeof(buf)-1));
+	if (copy_from_user(buf, user_buf, buf_size))
+		return -EFAULT;
+	buf[buf_size] = 0;
+
+	err = strict_strtoul(buf, 0, &user_val);
+	if (err)
+		return -EINVAL;
+	if (user_val > 0xff) {
+		dev_err(&ab->i2c_client[0]->dev,
+			"debugfs error input > 0xff\n");
+		return -EINVAL;
+	}
+	err = mask_and_set_register_interruptible(
+		ab, (u8)ab->debug_bank,
+		(u8)ab->debug_address, 0xFF, (u8)user_val);
+	if (err)
+		return -EINVAL;
+
+	get_register_interruptible(ab, (u8)ab->debug_bank,
+		(u8)ab->debug_address, &regvalue);
+	if (err)
+		return -EINVAL;
+
+	return buf_size;
+}
+
+static const struct file_operations ab3550_bank_fops = {
+	.open = ab3550_bank_open,
+	.write = ab3550_bank_write,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+	.owner = THIS_MODULE,
+};
+
+static const struct file_operations ab3550_address_fops = {
+	.open = ab3550_address_open,
+	.write = ab3550_address_write,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+	.owner = THIS_MODULE,
+};
+
+static const struct file_operations ab3550_val_fops = {
+	.open = ab3550_val_open,
+	.write = ab3550_val_write,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+	.owner = THIS_MODULE,
+};
+
+static struct dentry *ab3550_dir;
+static struct dentry *ab3550_reg_file;
+static struct dentry *ab3550_bank_file;
+static struct dentry *ab3550_address_file;
+static struct dentry *ab3550_val_file;
+
+static inline void ab3550_setup_debugfs(struct ab3550 *ab)
+{
+	ab->debug_bank = 0;
+	ab->debug_address = 0x00;
+
+	ab3550_dir = debugfs_create_dir(AB3550_NAME_STRING, NULL);
+	if (!ab3550_dir)
+		goto exit_no_debugfs;
+
+	ab3550_reg_file = debugfs_create_file("all-registers",
+		S_IRUGO, ab3550_dir, ab, &ab3550_registers_fops);
+	if (!ab3550_reg_file)
+		goto exit_destroy_dir;
+
+	ab3550_bank_file = debugfs_create_file("register-bank",
+		(S_IRUGO | S_IWUGO), ab3550_dir, ab, &ab3550_bank_fops);
+	if (!ab3550_bank_file)
+		goto exit_destroy_reg;
+
+	ab3550_address_file = debugfs_create_file("register-address",
+		(S_IRUGO | S_IWUGO), ab3550_dir, ab, &ab3550_address_fops);
+	if (!ab3550_address_file)
+		goto exit_destroy_bank;
+
+	ab3550_val_file = debugfs_create_file("register-value",
+		(S_IRUGO | S_IWUGO), ab3550_dir, ab, &ab3550_val_fops);
+	if (!ab3550_val_file)
+		goto exit_destroy_address;
+
+	return;
+
+exit_destroy_address:
+	debugfs_remove(ab3550_address_file);
+exit_destroy_bank:
+	debugfs_remove(ab3550_bank_file);
+exit_destroy_reg:
+	debugfs_remove(ab3550_reg_file);
+exit_destroy_dir:
+	debugfs_remove(ab3550_dir);
+exit_no_debugfs:
+	dev_err(&ab->i2c_client[0]->dev, "failed to create debugfs entries.\n");
+	return;
+}
+
+static inline void ab3550_remove_debugfs(void)
+{
+	debugfs_remove(ab3550_val_file);
+	debugfs_remove(ab3550_address_file);
+	debugfs_remove(ab3550_bank_file);
+	debugfs_remove(ab3550_reg_file);
+	debugfs_remove(ab3550_dir);
+}
+
+#else /* !CONFIG_DEBUG_FS */
+static inline void ab3550_setup_debugfs(struct ab3550 *ab)
+{
+}
+static inline void ab3550_remove_debugfs(void)
+{
+}
+#endif
+
+/*
+ * Basic set-up, datastructure creation/destruction and I2C interface.
+ * This sets up a default config in the AB3550 chip so that it
+ * will work as expected.
+ */
+static int __init ab3550_setup(struct ab3550 *ab)
+{
+	int err = 0;
+	int i;
+	struct ab3550_platform_data *plf_data;
+	struct abx500_init_settings *settings;
+
+	plf_data = ab->i2c_client[0]->dev.platform_data;
+	settings = plf_data->init_settings;
+
+	for (i = 0; i < plf_data->init_settings_sz; i++) {
+		err = mask_and_set_register_interruptible(ab,
+			settings[i].bank,
+			settings[i].reg,
+			0xFF, settings[i].setting);
+		if (err)
+			goto exit_no_setup;
+
+		/* If event mask register update the event mask in ab3550 */
+		if ((settings[i].bank == 0) &&
+			(AB3550_IMR1 <= settings[i].reg) &&
+			(settings[i].reg <= AB3550_IMR5)) {
+			ab->event_mask[settings[i].reg - AB3550_IMR1] =
+				settings[i].setting;
+		}
+	}
+exit_no_setup:
+	return err;
+}
+
+static void ab3550_mask_work(struct work_struct *work)
+{
+	struct ab3550 *ab = container_of(work, struct ab3550, mask_work);
+	int i;
+	unsigned long flags;
+	u8 mask[AB3550_NUM_EVENT_REG];
+
+	spin_lock_irqsave(&ab->event_lock, flags);
+	for (i = 0; i < AB3550_NUM_EVENT_REG; i++)
+		mask[i] = ab->event_mask[i];
+	spin_unlock_irqrestore(&ab->event_lock, flags);
+
+	for (i = 0; i < AB3550_NUM_EVENT_REG; i++) {
+		int err;
+
+		err = mask_and_set_register_interruptible(ab, 0,
+			(AB3550_IMR1 + i), ~0, mask[i]);
+		if (err)
+			dev_err(&ab->i2c_client[0]->dev,
+				"ab3550_mask_work failed 0x%x,0x%x\n",
+				(AB3550_IMR1 + i), mask[i]);
+	}
+}
+
+static void ab3550_mask(unsigned int irq)
+{
+	unsigned long flags;
+	struct ab3550 *ab;
+	struct ab3550_platform_data *plf_data;
+
+	ab = get_irq_chip_data(irq);
+	plf_data = ab->i2c_client[0]->dev.platform_data;
+	irq -= plf_data->irq.base;
+
+	spin_lock_irqsave(&ab->event_lock, flags);
+	ab->event_mask[irq / 8] |= BIT(irq % 8);
+	spin_unlock_irqrestore(&ab->event_lock, flags);
+
+	schedule_work(&ab->mask_work);
+}
+
+static void ab3550_unmask(unsigned int irq)
+{
+	unsigned long flags;
+	struct ab3550 *ab;
+	struct ab3550_platform_data *plf_data;
+
+	ab = get_irq_chip_data(irq);
+	plf_data = ab->i2c_client[0]->dev.platform_data;
+	irq -= plf_data->irq.base;
+
+	spin_lock_irqsave(&ab->event_lock, flags);
+	ab->event_mask[irq / 8] &= ~BIT(irq % 8);
+	spin_unlock_irqrestore(&ab->event_lock, flags);
+
+	schedule_work(&ab->mask_work);
+}
+
+static void noop(unsigned int irq)
+{
+}
+
+static struct irq_chip ab3550_irq_chip = {
+	.name		= "ab3550-core", /* Keep the same name as the request */
+	.startup	= NULL, /* defaults to enable */
+	.shutdown	= NULL, /* defaults to disable */
+	.enable		= NULL, /* defaults to unmask */
+	.disable	= ab3550_mask, /* No default to mask in chip.c */
+	.ack		= noop,
+	.mask		= ab3550_mask,
+	.unmask		= ab3550_unmask,
+	.end		= NULL,
+};
+
+struct ab_family_id {
+	u8	id;
+	char	*name;
+};
+
+static const struct ab_family_id ids[] __initdata = {
+	/* AB3550 */
+	{
+		.id = AB3550_P1A,
+		.name = "P1A"
+	},
+	/* Terminator */
+	{
+		.id = 0x00,
+	}
+};
+
+static int __init ab3550_probe(struct i2c_client *client,
+	const struct i2c_device_id *id)
+{
+	struct ab3550 *ab;
+	struct ab3550_platform_data *ab3550_plf_data =
+		client->dev.platform_data;
+	int err;
+	int i;
+	int num_i2c_clients = 0;
+
+	ab = kzalloc(sizeof(struct ab3550), GFP_KERNEL);
+	if (!ab) {
+		dev_err(&client->dev,
+			"could not allocate " AB3550_NAME_STRING " device\n");
+		return -ENOMEM;
+	}
+
+	/* Initialize data structure */
+	mutex_init(&ab->access_mutex);
+	spin_lock_init(&ab->event_lock);
+	ab->i2c_client[0] = client;
+
+	i2c_set_clientdata(client, ab);
+
+	/* Read chip ID register */
+	err = get_register_interruptible(ab, 0, AB3550_CID_REG, &ab->chip_id);
+	if (err) {
+		dev_err(&client->dev, "could not communicate with the analog "
+			"baseband chip\n");
+		goto exit_no_detect;
+	}
+
+	for (i = 0; ids[i].id != 0x0; i++) {
+		if (ids[i].id == ab->chip_id) {
+			snprintf(&ab->chip_name[0], sizeof(ab->chip_name) - 1,
+				AB3550_ID_FORMAT_STRING, ids[i].name);
+			break;
+		}
+	}
+
+	if (ids[i].id == 0x0) {
+		dev_err(&client->dev, "unknown analog baseband chip id: 0x%x\n",
+			ab->chip_id);
+		dev_err(&client->dev, "driver not started!\n");
+		goto exit_no_detect;
+	}
+
+	dev_info(&client->dev, "detected AB chip: %s\n", &ab->chip_name[0]);
+
+	/* Attach other dummy I2C clients. */
+	while (++num_i2c_clients < AB3550_NUM_BANKS) {
+		ab->i2c_client[num_i2c_clients] =
+			i2c_new_dummy(client->adapter,
+				(client->addr + num_i2c_clients));
+		if (!ab->i2c_client[num_i2c_clients]) {
+			err = -ENOMEM;
+			goto exit_no_dummy_client;
+		}
+		strlcpy(ab->i2c_client[num_i2c_clients]->name, id->name,
+			sizeof(ab->i2c_client[num_i2c_clients]->name));
+	}
+
+	err = ab3550_setup(ab);
+	if (err)
+		goto exit_no_setup;
+
+	INIT_WORK(&ab->mask_work, ab3550_mask_work);
+
+	for (i = 0; i < ab3550_plf_data->irq.count; i++) {
+		unsigned int irq;
+
+		irq = ab3550_plf_data->irq.base + i;
+		set_irq_chip_data(irq, ab);
+		set_irq_chip_and_handler(irq, &ab3550_irq_chip,
+			handle_simple_irq);
+		set_irq_nested_thread(irq, 1);
+#ifdef CONFIG_ARM
+		set_irq_flags(irq, IRQF_VALID);
+#else
+		set_irq_noprobe(irq);
+#endif
+	}
+
+	err = request_threaded_irq(client->irq, NULL, ab3550_irq_handler,
+		IRQF_ONESHOT, "ab3550-core", ab);
+	/* This real unpredictable IRQ is of course sampled for entropy */
+	rand_initialize_irq(client->irq);
+
+	if (err)
+		goto exit_no_irq;
+
+	err = abx500_register_ops(&client->dev, &ab3550_ops);
+	if (err)
+		goto exit_no_ops;
+
+	/* Set up and register the platform devices. */
+	for (i = 0; i < AB3550_NUM_DEVICES; i++) {
+		ab3550_devs[i].platform_data = ab3550_plf_data->dev_data[i];
+		ab3550_devs[i].data_size = ab3550_plf_data->dev_data_sz[i];
+	}
+
+	err = mfd_add_devices(&client->dev, 0, ab3550_devs,
+		ARRAY_SIZE(ab3550_devs), NULL,
+		ab3550_plf_data->irq.base);
+
+	ab3550_setup_debugfs(ab);
+
+	return 0;
+
+exit_no_ops:
+exit_no_irq:
+exit_no_setup:
+exit_no_dummy_client:
+	/* Unregister the dummy i2c clients. */
+	while (--num_i2c_clients)
+		i2c_unregister_device(ab->i2c_client[num_i2c_clients]);
+exit_no_detect:
+	kfree(ab);
+	return err;
+}
+
+static int __exit ab3550_remove(struct i2c_client *client)
+{
+	struct ab3550 *ab = i2c_get_clientdata(client);
+	int num_i2c_clients = AB3550_NUM_BANKS;
+
+	mfd_remove_devices(&client->dev);
+	ab3550_remove_debugfs();
+
+	while (--num_i2c_clients)
+		i2c_unregister_device(ab->i2c_client[num_i2c_clients]);
+
+	/*
+	 * At this point, all subscribers should have unregistered
+	 * their notifiers so deactivate IRQ
+	 */
+	free_irq(client->irq, ab);
+	i2c_set_clientdata(client, NULL);
+	kfree(ab);
+	return 0;
+}
+
+static const struct i2c_device_id ab3550_id[] = {
+	{AB3550_NAME_STRING, 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, ab3550_id);
+
+static struct i2c_driver ab3550_driver = {
+	.driver = {
+		.name	= AB3550_NAME_STRING,
+		.owner	= THIS_MODULE,
+	},
+	.id_table	= ab3550_id,
+	.probe		= ab3550_probe,
+	.remove		= __exit_p(ab3550_remove),
+};
+
+static int __init ab3550_i2c_init(void)
+{
+	return i2c_add_driver(&ab3550_driver);
+}
+
+static void __exit ab3550_i2c_exit(void)
+{
+	i2c_del_driver(&ab3550_driver);
+}
+
+subsys_initcall(ab3550_i2c_init);
+module_exit(ab3550_i2c_exit);
+
+MODULE_AUTHOR("Mattias Wallin <mattias.wallin@stericsson.com>");
+MODULE_DESCRIPTION("AB3550 core driver");
+MODULE_LICENSE("GPL");