mfd: New AB8500 driver

Add a new driver to support the AB8500 Power Management chip, replacing
the current AB4500.  The new driver replaces the old one, instead of an
incremental modification, because this is a substantial overhaul
including:

 - Split of the driver into -core and -spi portions, to allow another
   interface layer to be added

 - Addition of interrupt support

 - Switch to MFD core API for handling subdevices

 - Simplification of the APIs to remove a redundant block parameter

 - Rename of the APIs and macros from ab4500_* to ab8500_*

 - Rename of the files from ab4500* to ab8500*

 - Change of the driver name from ab4500 to ab8500

Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

5 files changed, 583 insertions, 214 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b84b707..9da0e50 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -420,11 +420,12 @@ config EZX_PCAP
 	  This enables the PCAP ASIC present on EZX Phones. This is
 	  needed for MMC, TouchScreen, Sound, USB, etc..
 
-config AB4500_CORE
-	tristate "ST-Ericsson's AB4500 Mixed Signal Power management chip"
-	depends on SPI
+config AB8500_CORE
+	bool "ST-Ericsson AB8500 Mixed Signal Power Management chip"
+	depends on SPI=y && GENERIC_HARDIRQS
+	select MFD_CORE
 	help
-	  Select this option to enable access to AB4500 power management
+	  Select this option to enable access to AB8500 power management
 	  chip. This connects to U8500 on the SSP/SPI bus and exports
 	  read/write functions for the devices to get access to this chip.
 	  This chip embeds various other multimedia funtionalities as well.
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index ca1517e..fb503e7 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -64,8 +64,8 @@ obj-$(CONFIG_PCF50633_GPIO)	+= pcf50633-gpio.o
 obj-$(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-$(CONFIG_AB8500_CORE)	+= ab8500-core.o ab8500-spi.o
 obj-$(CONFIG_MFD_TIMBERDALE)    += timberdale.o
 obj-$(CONFIG_PMIC_ADP5520)	+= adp5520.o
 obj-$(CONFIG_LPC_SCH)		+= lpc_sch.o
diff --git a/drivers/mfd/ab4500-core.c b/drivers/mfd/ab4500-core.c
deleted file mode 100644
index c275daa..0000000
--- a/drivers/mfd/ab4500-core.c
+++ /dev/null
@@ -1,209 +0,0 @@
-/*
- * Copyright (C) 2009 ST-Ericsson
- *
- * Author: Srinidhi KASAGAR <srinidhi.kasagar@stericsson.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.
- *
- * AB4500 is a companion power management chip used with U8500.
- * On this platform, this is interfaced with SSP0 controller
- * which is a ARM primecell pl022.
- *
- * At the moment the module just exports read/write features.
- * Interrupt management to be added - TODO.
- */
-#include <linux/kernel.h>
-#include <linux/slab.h>
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/spi/spi.h>
-#include <linux/mfd/ab4500.h>
-
-/* just required if probe fails, we need to
- * unregister the device
- */
-static struct spi_driver ab4500_driver;
-
-/*
- * This funtion writes to any AB4500 registers using
- * SPI protocol &  before it writes it packs the data
- * in the below 24 bit frame format
- *
- *	 *|------------------------------------|
- *	 *| 23|22...18|17.......10|9|8|7......0|
- *	 *| r/w  bank       adr          data  |
- *	 * ------------------------------------
- *
- * This function shouldn't be called from interrupt
- * context
- */
-int ab4500_write(struct ab4500 *ab4500, unsigned char block,
-		unsigned long addr, unsigned char data)
-{
-	struct spi_transfer xfer;
-	struct spi_message	msg;
-	int err;
-	unsigned long spi_data =
-		block << 18 | addr << 10 | data;
-
-	mutex_lock(&ab4500->lock);
-	ab4500->tx_buf[0] = spi_data;
-	ab4500->rx_buf[0] = 0;
-
-	xfer.tx_buf	= ab4500->tx_buf;
-	xfer.rx_buf 	= NULL;
-	xfer.len	= sizeof(unsigned long);
-
-	spi_message_init(&msg);
-	spi_message_add_tail(&xfer, &msg);
-
-	err = spi_sync(ab4500->spi, &msg);
-	mutex_unlock(&ab4500->lock);
-
-	return err;
-}
-EXPORT_SYMBOL(ab4500_write);
-
-int ab4500_read(struct ab4500 *ab4500, unsigned char block,
-		unsigned long addr)
-{
-	struct spi_transfer xfer;
-	struct spi_message	msg;
-	unsigned long spi_data =
-		1 << 23 | block << 18 | addr << 10;
-
-	mutex_lock(&ab4500->lock);
-	ab4500->tx_buf[0] = spi_data;
-	ab4500->rx_buf[0] = 0;
-
-	xfer.tx_buf	= ab4500->tx_buf;
-	xfer.rx_buf 	= ab4500->rx_buf;
-	xfer.len	= sizeof(unsigned long);
-
-	spi_message_init(&msg);
-	spi_message_add_tail(&xfer, &msg);
-
-	spi_sync(ab4500->spi, &msg);
-	mutex_unlock(&ab4500->lock);
-
-	return  ab4500->rx_buf[0];
-}
-EXPORT_SYMBOL(ab4500_read);
-
-/* ref: ab3100 core */
-#define AB4500_DEVICE(devname, devid)				\
-static struct platform_device ab4500_##devname##_device = {	\
-	.name	= devid,					\
-	.id	= -1,						\
-}
-
-/* list of childern devices of ab4500 - all are
- * not populated here - TODO
- */
-AB4500_DEVICE(charger, "ab4500-charger");
-AB4500_DEVICE(audio, "ab4500-audio");
-AB4500_DEVICE(usb, "ab4500-usb");
-AB4500_DEVICE(tvout, "ab4500-tvout");
-AB4500_DEVICE(sim, "ab4500-sim");
-AB4500_DEVICE(gpadc, "ab4500-gpadc");
-AB4500_DEVICE(clkmgt, "ab4500-clkmgt");
-AB4500_DEVICE(misc, "ab4500-misc");
-
-static struct platform_device *ab4500_platform_devs[] = {
-	&ab4500_charger_device,
-	&ab4500_audio_device,
-	&ab4500_usb_device,
-	&ab4500_tvout_device,
-	&ab4500_sim_device,
-	&ab4500_gpadc_device,
-	&ab4500_clkmgt_device,
-	&ab4500_misc_device,
-};
-
-static int __init ab4500_probe(struct spi_device *spi)
-{
-	struct ab4500	*ab4500;
-	unsigned char revision;
-	int err = 0;
-	int i;
-
-	ab4500 = kzalloc(sizeof *ab4500, GFP_KERNEL);
-	if (!ab4500) {
-		dev_err(&spi->dev, "could not allocate AB4500\n");
-		err = -ENOMEM;
-		goto not_detect;
-	}
-
-	ab4500->spi = spi;
-	spi_set_drvdata(spi, ab4500);
-
-	mutex_init(&ab4500->lock);
-
-	/* read the revision register */
-	revision = ab4500_read(ab4500, AB4500_MISC, AB4500_REV_REG);
-
-	/* revision id 0x0 is for early drop, 0x10 is for cut1.0 */
-	if (revision == 0x0 || revision == 0x10)
-		dev_info(&spi->dev, "Detected chip: %s, revision = %x\n",
-			ab4500_driver.driver.name, revision);
-	else	{
-		dev_err(&spi->dev, "unknown chip: 0x%x\n", revision);
-		goto not_detect;
-	}
-
-	for (i = 0; i < ARRAY_SIZE(ab4500_platform_devs); i++)	{
-		ab4500_platform_devs[i]->dev.parent =
-			&spi->dev;
-		platform_set_drvdata(ab4500_platform_devs[i], ab4500);
-	}
-
-	/* register the ab4500 platform devices */
-	platform_add_devices(ab4500_platform_devs,
-			ARRAY_SIZE(ab4500_platform_devs));
-
-	return err;
-
- not_detect:
-	spi_unregister_driver(&ab4500_driver);
-	kfree(ab4500);
-	return err;
-}
-
-static int __devexit ab4500_remove(struct spi_device *spi)
-{
-	struct ab4500 *ab4500 =
-		spi_get_drvdata(spi);
-
-	kfree(ab4500);
-
-	return 0;
-}
-
-static struct spi_driver ab4500_driver = {
-	.driver = {
-		.name = "ab4500",
-		.owner = THIS_MODULE,
-	},
-	.probe = ab4500_probe,
-	.remove = __devexit_p(ab4500_remove)
-};
-
-static int __devinit ab4500_init(void)
-{
-	return spi_register_driver(&ab4500_driver);
-}
-
-static void __exit ab4500_exit(void)
-{
-	spi_unregister_driver(&ab4500_driver);
-}
-
-subsys_initcall(ab4500_init);
-module_exit(ab4500_exit);
-
-MODULE_AUTHOR("Srinidhi KASAGAR <srinidhi.kasagar@stericsson.com");
-MODULE_DESCRIPTION("AB4500 core driver");
-MODULE_LICENSE("GPL");
diff --git a/drivers/mfd/ab8500-core.c b/drivers/mfd/ab8500-core.c
new file mode 100644
index 0000000..f3d26fa
--- /dev/null
+++ b/drivers/mfd/ab8500-core.c
@@ -0,0 +1,444 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * License Terms: GNU General Public License v2
+ * Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
+ * Author: Rabin Vincent <rabin.vincent@stericsson.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/ab8500.h>
+
+/*
+ * Interrupt register offsets
+ * Bank : 0x0E
+ */
+#define AB8500_IT_SOURCE1_REG		0x0E00
+#define AB8500_IT_SOURCE2_REG		0x0E01
+#define AB8500_IT_SOURCE3_REG		0x0E02
+#define AB8500_IT_SOURCE4_REG		0x0E03
+#define AB8500_IT_SOURCE5_REG		0x0E04
+#define AB8500_IT_SOURCE6_REG		0x0E05
+#define AB8500_IT_SOURCE7_REG		0x0E06
+#define AB8500_IT_SOURCE8_REG		0x0E07
+#define AB8500_IT_SOURCE19_REG		0x0E12
+#define AB8500_IT_SOURCE20_REG		0x0E13
+#define AB8500_IT_SOURCE21_REG		0x0E14
+#define AB8500_IT_SOURCE22_REG		0x0E15
+#define AB8500_IT_SOURCE23_REG		0x0E16
+#define AB8500_IT_SOURCE24_REG		0x0E17
+
+/*
+ * latch registers
+ */
+#define AB8500_IT_LATCH1_REG		0x0E20
+#define AB8500_IT_LATCH2_REG		0x0E21
+#define AB8500_IT_LATCH3_REG		0x0E22
+#define AB8500_IT_LATCH4_REG		0x0E23
+#define AB8500_IT_LATCH5_REG		0x0E24
+#define AB8500_IT_LATCH6_REG		0x0E25
+#define AB8500_IT_LATCH7_REG		0x0E26
+#define AB8500_IT_LATCH8_REG		0x0E27
+#define AB8500_IT_LATCH9_REG		0x0E28
+#define AB8500_IT_LATCH10_REG		0x0E29
+#define AB8500_IT_LATCH19_REG		0x0E32
+#define AB8500_IT_LATCH20_REG		0x0E33
+#define AB8500_IT_LATCH21_REG		0x0E34
+#define AB8500_IT_LATCH22_REG		0x0E35
+#define AB8500_IT_LATCH23_REG		0x0E36
+#define AB8500_IT_LATCH24_REG		0x0E37
+
+/*
+ * mask registers
+ */
+
+#define AB8500_IT_MASK1_REG		0x0E40
+#define AB8500_IT_MASK2_REG		0x0E41
+#define AB8500_IT_MASK3_REG		0x0E42
+#define AB8500_IT_MASK4_REG		0x0E43
+#define AB8500_IT_MASK5_REG		0x0E44
+#define AB8500_IT_MASK6_REG		0x0E45
+#define AB8500_IT_MASK7_REG		0x0E46
+#define AB8500_IT_MASK8_REG		0x0E47
+#define AB8500_IT_MASK9_REG		0x0E48
+#define AB8500_IT_MASK10_REG		0x0E49
+#define AB8500_IT_MASK11_REG		0x0E4A
+#define AB8500_IT_MASK12_REG		0x0E4B
+#define AB8500_IT_MASK13_REG		0x0E4C
+#define AB8500_IT_MASK14_REG		0x0E4D
+#define AB8500_IT_MASK15_REG		0x0E4E
+#define AB8500_IT_MASK16_REG		0x0E4F
+#define AB8500_IT_MASK17_REG		0x0E50
+#define AB8500_IT_MASK18_REG		0x0E51
+#define AB8500_IT_MASK19_REG		0x0E52
+#define AB8500_IT_MASK20_REG		0x0E53
+#define AB8500_IT_MASK21_REG		0x0E54
+#define AB8500_IT_MASK22_REG		0x0E55
+#define AB8500_IT_MASK23_REG		0x0E56
+#define AB8500_IT_MASK24_REG		0x0E57
+
+#define AB8500_REV_REG			0x1080
+
+/*
+ * Map interrupt numbers to the LATCH and MASK register offsets, Interrupt
+ * numbers are indexed into this array with (num / 8).
+ *
+ * This is one off from the register names, i.e. AB8500_IT_MASK1_REG is at
+ * offset 0.
+ */
+static const int ab8500_irq_regoffset[AB8500_NUM_IRQ_REGS] = {
+	0, 1, 2, 3, 4, 6, 7, 8, 9, 18, 19, 20, 21,
+};
+
+static int __ab8500_write(struct ab8500 *ab8500, u16 addr, u8 data)
+{
+	int ret;
+
+	dev_vdbg(ab8500->dev, "wr: addr %#x <= %#x\n", addr, data);
+
+	ret = ab8500->write(ab8500, addr, data);
+	if (ret < 0)
+		dev_err(ab8500->dev, "failed to write reg %#x: %d\n",
+			addr, ret);
+
+	return ret;
+}
+
+/**
+ * ab8500_write() - write an AB8500 register
+ * @ab8500: device to write to
+ * @addr: address of the register
+ * @data: value to write
+ */
+int ab8500_write(struct ab8500 *ab8500, u16 addr, u8 data)
+{
+	int ret;
+
+	mutex_lock(&ab8500->lock);
+	ret = __ab8500_write(ab8500, addr, data);
+	mutex_unlock(&ab8500->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ab8500_write);
+
+static int __ab8500_read(struct ab8500 *ab8500, u16 addr)
+{
+	int ret;
+
+	ret = ab8500->read(ab8500, addr);
+	if (ret < 0)
+		dev_err(ab8500->dev, "failed to read reg %#x: %d\n",
+			addr, ret);
+
+	dev_vdbg(ab8500->dev, "rd: addr %#x => data %#x\n", addr, ret);
+
+	return ret;
+}
+
+/**
+ * ab8500_read() - read an AB8500 register
+ * @ab8500: device to read from
+ * @addr: address of the register
+ */
+int ab8500_read(struct ab8500 *ab8500, u16 addr)
+{
+	int ret;
+
+	mutex_lock(&ab8500->lock);
+	ret = __ab8500_read(ab8500, addr);
+	mutex_unlock(&ab8500->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ab8500_read);
+
+/**
+ * ab8500_set_bits() - set a bitfield in an AB8500 register
+ * @ab8500: device to read from
+ * @addr: address of the register
+ * @mask: mask of the bitfield to modify
+ * @data: value to set to the bitfield
+ */
+int ab8500_set_bits(struct ab8500 *ab8500, u16 addr, u8 mask, u8 data)
+{
+	int ret;
+
+	mutex_lock(&ab8500->lock);
+
+	ret = __ab8500_read(ab8500, addr);
+	if (ret < 0)
+		goto out;
+
+	ret &= ~mask;
+	ret |= data;
+
+	ret = __ab8500_write(ab8500, addr, ret);
+
+out:
+	mutex_unlock(&ab8500->lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ab8500_set_bits);
+
+static void ab8500_irq_lock(unsigned int irq)
+{
+	struct ab8500 *ab8500 = get_irq_chip_data(irq);
+
+	mutex_lock(&ab8500->irq_lock);
+}
+
+static void ab8500_irq_sync_unlock(unsigned int irq)
+{
+	struct ab8500 *ab8500 = get_irq_chip_data(irq);
+	int i;
+
+	for (i = 0; i < AB8500_NUM_IRQ_REGS; i++) {
+		u8 old = ab8500->oldmask[i];
+		u8 new = ab8500->mask[i];
+		int reg;
+
+		if (new == old)
+			continue;
+
+		ab8500->oldmask[i] = new;
+
+		reg = AB8500_IT_MASK1_REG + ab8500_irq_regoffset[i];
+		ab8500_write(ab8500, reg, new);
+	}
+
+	mutex_unlock(&ab8500->irq_lock);
+}
+
+static void ab8500_irq_mask(unsigned int irq)
+{
+	struct ab8500 *ab8500 = get_irq_chip_data(irq);
+	int offset = irq - ab8500->irq_base;
+	int index = offset / 8;
+	int mask = 1 << (offset % 8);
+
+	ab8500->mask[index] |= mask;
+}
+
+static void ab8500_irq_unmask(unsigned int irq)
+{
+	struct ab8500 *ab8500 = get_irq_chip_data(irq);
+	int offset = irq - ab8500->irq_base;
+	int index = offset / 8;
+	int mask = 1 << (offset % 8);
+
+	ab8500->mask[index] &= ~mask;
+}
+
+static struct irq_chip ab8500_irq_chip = {
+	.name			= "ab8500",
+	.bus_lock		= ab8500_irq_lock,
+	.bus_sync_unlock	= ab8500_irq_sync_unlock,
+	.mask			= ab8500_irq_mask,
+	.unmask			= ab8500_irq_unmask,
+};
+
+static irqreturn_t ab8500_irq(int irq, void *dev)
+{
+	struct ab8500 *ab8500 = dev;
+	int i;
+
+	dev_vdbg(ab8500->dev, "interrupt\n");
+
+	for (i = 0; i < AB8500_NUM_IRQ_REGS; i++) {
+		int regoffset = ab8500_irq_regoffset[i];
+		int status;
+
+		status = ab8500_read(ab8500, AB8500_IT_LATCH1_REG + regoffset);
+		if (status <= 0)
+			continue;
+
+		do {
+			int bit = __ffs(status);
+			int line = i * 8 + bit;
+
+			handle_nested_irq(ab8500->irq_base + line);
+			status &= ~(1 << bit);
+		} while (status);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int ab8500_irq_init(struct ab8500 *ab8500)
+{
+	int base = ab8500->irq_base;
+	int irq;
+
+	for (irq = base; irq < base + AB8500_NR_IRQS; irq++) {
+		set_irq_chip_data(irq, ab8500);
+		set_irq_chip_and_handler(irq, &ab8500_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
+	}
+
+	return 0;
+}
+
+static void ab8500_irq_remove(struct ab8500 *ab8500)
+{
+	int base = ab8500->irq_base;
+	int irq;
+
+	for (irq = base; irq < base + AB8500_NR_IRQS; irq++) {
+#ifdef CONFIG_ARM
+		set_irq_flags(irq, 0);
+#endif
+		set_irq_chip_and_handler(irq, NULL, NULL);
+		set_irq_chip_data(irq, NULL);
+	}
+}
+
+static struct resource ab8500_gpadc_resources[] = {
+	{
+		.name	= "HW_CONV_END",
+		.start	= AB8500_INT_GP_HW_ADC_CONV_END,
+		.end	= AB8500_INT_GP_HW_ADC_CONV_END,
+		.flags	= IORESOURCE_IRQ,
+	},
+	{
+		.name	= "SW_CONV_END",
+		.start	= AB8500_INT_GP_SW_ADC_CONV_END,
+		.end	= AB8500_INT_GP_SW_ADC_CONV_END,
+		.flags	= IORESOURCE_IRQ,
+	},
+};
+
+static struct resource ab8500_rtc_resources[] = {
+	{
+		.name	= "60S",
+		.start	= AB8500_INT_RTC_60S,
+		.end	= AB8500_INT_RTC_60S,
+		.flags	= IORESOURCE_IRQ,
+	},
+	{
+		.name	= "ALARM",
+		.start	= AB8500_INT_RTC_ALARM,
+		.end	= AB8500_INT_RTC_ALARM,
+		.flags	= IORESOURCE_IRQ,
+	},
+};
+
+static struct mfd_cell ab8500_devs[] = {
+	{
+		.name = "ab8500-gpadc",
+		.num_resources = ARRAY_SIZE(ab8500_gpadc_resources),
+		.resources = ab8500_gpadc_resources,
+	},
+	{
+		.name = "ab8500-rtc",
+		.num_resources = ARRAY_SIZE(ab8500_rtc_resources),
+		.resources = ab8500_rtc_resources,
+	},
+	{ .name = "ab8500-charger", },
+	{ .name = "ab8500-audio", },
+	{ .name = "ab8500-usb", },
+	{ .name = "ab8500-pwm", },
+};
+
+int __devinit ab8500_init(struct ab8500 *ab8500)
+{
+	struct ab8500_platform_data *plat = dev_get_platdata(ab8500->dev);
+	int ret;
+	int i;
+
+	if (plat)
+		ab8500->irq_base = plat->irq_base;
+
+	mutex_init(&ab8500->lock);
+	mutex_init(&ab8500->irq_lock);
+
+	ret = ab8500_read(ab8500, AB8500_REV_REG);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * 0x0 - Early Drop
+	 * 0x10 - Cut 1.0
+	 * 0x11 - Cut 1.1
+	 */
+	if (ret == 0x0 || ret == 0x10 || ret == 0x11) {
+		ab8500->revision = ret;
+		dev_info(ab8500->dev, "detected chip, revision: %#x\n", ret);
+	} else {
+		dev_err(ab8500->dev, "unknown chip, revision: %#x\n", ret);
+		return -EINVAL;
+	}
+
+	if (plat && plat->init)
+		plat->init(ab8500);
+
+	/* Clear and mask all interrupts */
+	for (i = 0; i < 10; i++) {
+		ab8500_read(ab8500, AB8500_IT_LATCH1_REG + i);
+		ab8500_write(ab8500, AB8500_IT_MASK1_REG + i, 0xff);
+	}
+
+	for (i = 18; i < 24; i++) {
+		ab8500_read(ab8500, AB8500_IT_LATCH1_REG + i);
+		ab8500_write(ab8500, AB8500_IT_MASK1_REG + i, 0xff);
+	}
+
+	for (i = 0; i < AB8500_NUM_IRQ_REGS; i++)
+		ab8500->mask[i] = ab8500->oldmask[i] = 0xff;
+
+	if (ab8500->irq_base) {
+		ret = ab8500_irq_init(ab8500);
+		if (ret)
+			return ret;
+
+		ret = request_threaded_irq(ab8500->irq, NULL, ab8500_irq,
+					   IRQF_ONESHOT, "ab8500", ab8500);
+		if (ret)
+			goto out_removeirq;
+	}
+
+	ret = mfd_add_devices(ab8500->dev, -1, ab8500_devs,
+			      ARRAY_SIZE(ab8500_devs), NULL,
+			      ab8500->irq_base);
+	if (ret)
+		goto out_freeirq;
+
+	return ret;
+
+out_freeirq:
+	if (ab8500->irq_base) {
+		free_irq(ab8500->irq, ab8500);
+out_removeirq:
+		ab8500_irq_remove(ab8500);
+	}
+	return ret;
+}
+
+int __devexit ab8500_exit(struct ab8500 *ab8500)
+{
+	mfd_remove_devices(ab8500->dev);
+	if (ab8500->irq_base) {
+		free_irq(ab8500->irq, ab8500);
+		ab8500_irq_remove(ab8500);
+	}
+
+	return 0;
+}
+
+MODULE_AUTHOR("Srinidhi Kasagar, Rabin Vincent");
+MODULE_DESCRIPTION("AB8500 MFD core");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mfd/ab8500-spi.c b/drivers/mfd/ab8500-spi.c
new file mode 100644
index 0000000..b81d4f7
--- /dev/null
+++ b/drivers/mfd/ab8500-spi.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * License Terms: GNU General Public License v2
+ * Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/mfd/ab8500.h>
+
+/*
+ * This funtion writes to any AB8500 registers using
+ * SPI protocol &  before it writes it packs the data
+ * in the below 24 bit frame format
+ *
+ *	 *|------------------------------------|
+ *	 *| 23|22...18|17.......10|9|8|7......0|
+ *	 *| r/w  bank       adr          data  |
+ *	 * ------------------------------------
+ *
+ * This function shouldn't be called from interrupt
+ * context
+ */
+static int ab8500_spi_write(struct ab8500 *ab8500, u16 addr, u8 data)
+{
+	struct spi_device *spi = container_of(ab8500->dev, struct spi_device,
+					      dev);
+	unsigned long spi_data = addr << 10 | data;
+	struct spi_transfer xfer;
+	struct spi_message msg;
+
+	ab8500->tx_buf[0] = spi_data;
+	ab8500->rx_buf[0] = 0;
+
+	xfer.tx_buf	= ab8500->tx_buf;
+	xfer.rx_buf	= NULL;
+	xfer.len	= sizeof(unsigned long);
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfer, &msg);
+
+	return spi_sync(spi, &msg);
+}
+
+static int ab8500_spi_read(struct ab8500 *ab8500, u16 addr)
+{
+	struct spi_device *spi = container_of(ab8500->dev, struct spi_device,
+					      dev);
+	unsigned long spi_data = 1 << 23 | addr << 10;
+	struct spi_transfer xfer;
+	struct spi_message msg;
+	int ret;
+
+	ab8500->tx_buf[0] = spi_data;
+	ab8500->rx_buf[0] = 0;
+
+	xfer.tx_buf	= ab8500->tx_buf;
+	xfer.rx_buf	= ab8500->rx_buf;
+	xfer.len	= sizeof(unsigned long);
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfer, &msg);
+
+	ret = spi_sync(spi, &msg);
+	if (!ret)
+		ret = ab8500->rx_buf[0];
+
+	return ret;
+}
+
+static int __devinit ab8500_spi_probe(struct spi_device *spi)
+{
+	struct ab8500 *ab8500;
+	int ret;
+
+	ab8500 = kzalloc(sizeof *ab8500, GFP_KERNEL);
+	if (!ab8500)
+		return -ENOMEM;
+
+	ab8500->dev = &spi->dev;
+	ab8500->irq = spi->irq;
+
+	ab8500->read = ab8500_spi_read;
+	ab8500->write = ab8500_spi_write;
+
+	spi_set_drvdata(spi, ab8500);
+
+	ret = ab8500_init(ab8500);
+	if (ret)
+		kfree(ab8500);
+
+	return ret;
+}
+
+static int __devexit ab8500_spi_remove(struct spi_device *spi)
+{
+	struct ab8500 *ab8500 = spi_get_drvdata(spi);
+
+	ab8500_exit(ab8500);
+	kfree(ab8500);
+
+	return 0;
+}
+
+static struct spi_driver ab8500_spi_driver = {
+	.driver = {
+		.name = "ab8500",
+		.owner = THIS_MODULE,
+	},
+	.probe	= ab8500_spi_probe,
+	.remove	= __devexit_p(ab8500_spi_remove)
+};
+
+static int __init ab8500_spi_init(void)
+{
+	return spi_register_driver(&ab8500_spi_driver);
+}
+subsys_initcall(ab8500_spi_init);
+
+static void __exit ab8500_spi_exit(void)
+{
+	spi_unregister_driver(&ab8500_spi_driver);
+}
+module_exit(ab8500_spi_exit);
+
+MODULE_AUTHOR("Srinidhi KASAGAR <srinidhi.kasagar@stericsson.com");
+MODULE_DESCRIPTION("AB8500 SPI");
+MODULE_LICENSE("GPL v2");