mfd: Initial core support for WM831x series devices

The WM831x series of devices are register compatible processor power
management subsystems, providing regulator and power path management
facilities along with other services like watchdog, RTC and touch
panel controllers.

This patch adds very basic support, providing basic single register
I2C access, handling of the security key and registration of the
devices.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 1357 insertions, 0 deletions

diff --git a/drivers/mfd/wm831x-core.c b/drivers/mfd/wm831x-core.c
new file mode 100644
index 000000000000..cc1040c9d46c
--- /dev/null
+++ b/drivers/mfd/wm831x-core.c
@@ -0,0 +1,1357 @@
+/*
+ * wm831x-core.c  --  Device access for Wolfson WM831x PMICs
+ *
+ * Copyright 2009 Wolfson Microelectronics PLC.
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/mfd/core.h>
+
+#include <linux/mfd/wm831x/core.h>
+#include <linux/mfd/wm831x/pdata.h>
+
+enum wm831x_parent {
+	WM8310 = 0,
+	WM8311 = 1,
+	WM8312 = 2,
+};
+
+static int wm831x_reg_locked(struct wm831x *wm831x, unsigned short reg)
+{
+	if (!wm831x->locked)
+		return 0;
+
+	switch (reg) {
+	case WM831X_WATCHDOG:
+	case WM831X_DC4_CONTROL:
+	case WM831X_ON_PIN_CONTROL:
+	case WM831X_BACKUP_CHARGER_CONTROL:
+	case WM831X_CHARGER_CONTROL_1:
+	case WM831X_CHARGER_CONTROL_2:
+		return 1;
+
+	default:
+		return 0;
+	}
+}
+
+/**
+ * wm831x_reg_unlock: Unlock user keyed registers
+ *
+ * The WM831x has a user key preventing writes to particularly
+ * critical registers.  This function locks those registers,
+ * allowing writes to them.
+ */
+void wm831x_reg_lock(struct wm831x *wm831x)
+{
+	int ret;
+
+	ret = wm831x_reg_write(wm831x, WM831X_SECURITY_KEY, 0);
+	if (ret == 0) {
+		dev_vdbg(wm831x->dev, "Registers locked\n");
+
+		mutex_lock(&wm831x->io_lock);
+		WARN_ON(wm831x->locked);
+		wm831x->locked = 1;
+		mutex_unlock(&wm831x->io_lock);
+	} else {
+		dev_err(wm831x->dev, "Failed to lock registers: %d\n", ret);
+	}
+
+}
+EXPORT_SYMBOL_GPL(wm831x_reg_lock);
+
+/**
+ * wm831x_reg_unlock: Unlock user keyed registers
+ *
+ * The WM831x has a user key preventing writes to particularly
+ * critical registers.  This function locks those registers,
+ * preventing spurious writes.
+ */
+int wm831x_reg_unlock(struct wm831x *wm831x)
+{
+	int ret;
+
+	/* 0x9716 is the value required to unlock the registers */
+	ret = wm831x_reg_write(wm831x, WM831X_SECURITY_KEY, 0x9716);
+	if (ret == 0) {
+		dev_vdbg(wm831x->dev, "Registers unlocked\n");
+
+		mutex_lock(&wm831x->io_lock);
+		WARN_ON(!wm831x->locked);
+		wm831x->locked = 0;
+		mutex_unlock(&wm831x->io_lock);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(wm831x_reg_unlock);
+
+static int wm831x_read(struct wm831x *wm831x, unsigned short reg,
+		       int bytes, void *dest)
+{
+	int ret, i;
+	u16 *buf = dest;
+
+	BUG_ON(bytes % 2);
+	BUG_ON(bytes <= 0);
+
+	ret = wm831x->read_dev(wm831x, reg, bytes, dest);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < bytes / 2; i++) {
+		buf[i] = be16_to_cpu(buf[i]);
+
+		dev_vdbg(wm831x->dev, "Read %04x from R%d(0x%x)\n",
+			 buf[i], reg + i, reg + i);
+	}
+
+	return 0;
+}
+
+/**
+ * wm831x_reg_read: Read a single WM831x register.
+ *
+ * @wm831x: Device to read from.
+ * @reg: Register to read.
+ */
+int wm831x_reg_read(struct wm831x *wm831x, unsigned short reg)
+{
+	unsigned short val;
+	int ret;
+
+	mutex_lock(&wm831x->io_lock);
+
+	ret = wm831x_read(wm831x, reg, 2, &val);
+
+	mutex_unlock(&wm831x->io_lock);
+
+	if (ret < 0)
+		return ret;
+	else
+		return val;
+}
+EXPORT_SYMBOL_GPL(wm831x_reg_read);
+
+/**
+ * wm831x_bulk_read: Read multiple WM831x registers
+ *
+ * @wm831x: Device to read from
+ * @reg: First register
+ * @count: Number of registers
+ * @buf: Buffer to fill.
+ */
+int wm831x_bulk_read(struct wm831x *wm831x, unsigned short reg,
+		     int count, u16 *buf)
+{
+	int ret;
+
+	mutex_lock(&wm831x->io_lock);
+
+	ret = wm831x_read(wm831x, reg, count * 2, buf);
+
+	mutex_unlock(&wm831x->io_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(wm831x_bulk_read);
+
+static int wm831x_write(struct wm831x *wm831x, unsigned short reg,
+			int bytes, void *src)
+{
+	u16 *buf = src;
+	int i;
+
+	BUG_ON(bytes % 2);
+	BUG_ON(bytes <= 0);
+
+	for (i = 0; i < bytes / 2; i++) {
+		if (wm831x_reg_locked(wm831x, reg))
+			return -EPERM;
+
+		dev_vdbg(wm831x->dev, "Write %04x to R%d(0x%x)\n",
+			 buf[i], reg + i, reg + i);
+
+		buf[i] = cpu_to_be16(buf[i]);
+	}
+
+	return wm831x->write_dev(wm831x, reg, bytes, src);
+}
+
+/**
+ * wm831x_reg_write: Write a single WM831x register.
+ *
+ * @wm831x: Device to write to.
+ * @reg: Register to write to.
+ * @val: Value to write.
+ */
+int wm831x_reg_write(struct wm831x *wm831x, unsigned short reg,
+		     unsigned short val)
+{
+	int ret;
+
+	mutex_lock(&wm831x->io_lock);
+
+	ret = wm831x_write(wm831x, reg, 2, &val);
+
+	mutex_unlock(&wm831x->io_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(wm831x_reg_write);
+
+/**
+ * wm831x_set_bits: Set the value of a bitfield in a WM831x register
+ *
+ * @wm831x: Device to write to.
+ * @reg: Register to write to.
+ * @mask: Mask of bits to set.
+ * @val: Value to set (unshifted)
+ */
+int wm831x_set_bits(struct wm831x *wm831x, unsigned short reg,
+		    unsigned short mask, unsigned short val)
+{
+	int ret;
+	u16 r;
+
+	mutex_lock(&wm831x->io_lock);
+
+	ret = wm831x_read(wm831x, reg, 2, &r);
+	if (ret < 0)
+		goto out;
+
+	r &= ~mask;
+	r |= val;
+
+	ret = wm831x_write(wm831x, reg, 2, &r);
+
+out:
+	mutex_unlock(&wm831x->io_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(wm831x_set_bits);
+
+static struct resource wm831x_dcdc1_resources[] = {
+	{
+		.start = WM831X_DC1_CONTROL_1,
+		.end   = WM831X_DC1_DVS_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.name  = "UV",
+		.start = WM831X_IRQ_UV_DC1,
+		.end   = WM831X_IRQ_UV_DC1,
+		.flags = IORESOURCE_IRQ,
+	},
+	{
+		.name  = "HC",
+		.start = WM831X_IRQ_HC_DC1,
+		.end   = WM831X_IRQ_HC_DC1,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+
+static struct resource wm831x_dcdc2_resources[] = {
+	{
+		.start = WM831X_DC2_CONTROL_1,
+		.end   = WM831X_DC2_DVS_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.name  = "UV",
+		.start = WM831X_IRQ_UV_DC2,
+		.end   = WM831X_IRQ_UV_DC2,
+		.flags = IORESOURCE_IRQ,
+	},
+	{
+		.name  = "HC",
+		.start = WM831X_IRQ_HC_DC2,
+		.end   = WM831X_IRQ_HC_DC2,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_dcdc3_resources[] = {
+	{
+		.start = WM831X_DC3_CONTROL_1,
+		.end   = WM831X_DC3_SLEEP_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.name  = "UV",
+		.start = WM831X_IRQ_UV_DC3,
+		.end   = WM831X_IRQ_UV_DC3,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_dcdc4_resources[] = {
+	{
+		.start = WM831X_DC4_CONTROL,
+		.end   = WM831X_DC4_SLEEP_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.name  = "UV",
+		.start = WM831X_IRQ_UV_DC4,
+		.end   = WM831X_IRQ_UV_DC4,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_gpio_resources[] = {
+	{
+		.start = WM831X_IRQ_GPIO_1,
+		.end   = WM831X_IRQ_GPIO_16,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_isink1_resources[] = {
+	{
+		.start = WM831X_CURRENT_SINK_1,
+		.end   = WM831X_CURRENT_SINK_1,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.start = WM831X_IRQ_CS1,
+		.end   = WM831X_IRQ_CS1,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_isink2_resources[] = {
+	{
+		.start = WM831X_CURRENT_SINK_2,
+		.end   = WM831X_CURRENT_SINK_2,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.start = WM831X_IRQ_CS2,
+		.end   = WM831X_IRQ_CS2,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_ldo1_resources[] = {
+	{
+		.start = WM831X_LDO1_CONTROL,
+		.end   = WM831X_LDO1_SLEEP_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.name  = "UV",
+		.start = WM831X_IRQ_UV_LDO1,
+		.end   = WM831X_IRQ_UV_LDO1,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_ldo2_resources[] = {
+	{
+		.start = WM831X_LDO2_CONTROL,
+		.end   = WM831X_LDO2_SLEEP_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.name  = "UV",
+		.start = WM831X_IRQ_UV_LDO2,
+		.end   = WM831X_IRQ_UV_LDO2,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_ldo3_resources[] = {
+	{
+		.start = WM831X_LDO3_CONTROL,
+		.end   = WM831X_LDO3_SLEEP_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.name  = "UV",
+		.start = WM831X_IRQ_UV_LDO3,
+		.end   = WM831X_IRQ_UV_LDO3,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_ldo4_resources[] = {
+	{
+		.start = WM831X_LDO4_CONTROL,
+		.end   = WM831X_LDO4_SLEEP_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.name  = "UV",
+		.start = WM831X_IRQ_UV_LDO4,
+		.end   = WM831X_IRQ_UV_LDO4,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_ldo5_resources[] = {
+	{
+		.start = WM831X_LDO5_CONTROL,
+		.end   = WM831X_LDO5_SLEEP_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.name  = "UV",
+		.start = WM831X_IRQ_UV_LDO5,
+		.end   = WM831X_IRQ_UV_LDO5,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_ldo6_resources[] = {
+	{
+		.start = WM831X_LDO6_CONTROL,
+		.end   = WM831X_LDO6_SLEEP_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.name  = "UV",
+		.start = WM831X_IRQ_UV_LDO6,
+		.end   = WM831X_IRQ_UV_LDO6,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_ldo7_resources[] = {
+	{
+		.start = WM831X_LDO7_CONTROL,
+		.end   = WM831X_LDO7_SLEEP_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.name  = "UV",
+		.start = WM831X_IRQ_UV_LDO7,
+		.end   = WM831X_IRQ_UV_LDO7,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_ldo8_resources[] = {
+	{
+		.start = WM831X_LDO8_CONTROL,
+		.end   = WM831X_LDO8_SLEEP_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.name  = "UV",
+		.start = WM831X_IRQ_UV_LDO8,
+		.end   = WM831X_IRQ_UV_LDO8,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_ldo9_resources[] = {
+	{
+		.start = WM831X_LDO9_CONTROL,
+		.end   = WM831X_LDO9_SLEEP_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.name  = "UV",
+		.start = WM831X_IRQ_UV_LDO9,
+		.end   = WM831X_IRQ_UV_LDO9,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_ldo10_resources[] = {
+	{
+		.start = WM831X_LDO10_CONTROL,
+		.end   = WM831X_LDO10_SLEEP_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+	{
+		.name  = "UV",
+		.start = WM831X_IRQ_UV_LDO10,
+		.end   = WM831X_IRQ_UV_LDO10,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_ldo11_resources[] = {
+	{
+		.start = WM831X_LDO11_ON_CONTROL,
+		.end   = WM831X_LDO11_SLEEP_CONTROL,
+		.flags = IORESOURCE_IO,
+	},
+};
+
+static struct resource wm831x_on_resources[] = {
+	{
+		.start = WM831X_IRQ_ON,
+		.end   = WM831X_IRQ_ON,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+
+static struct resource wm831x_power_resources[] = {
+	{
+		.name = "SYSLO",
+		.start = WM831X_IRQ_PPM_SYSLO,
+		.end   = WM831X_IRQ_PPM_SYSLO,
+		.flags = IORESOURCE_IRQ,
+	},
+	{
+		.name = "PWR SRC",
+		.start = WM831X_IRQ_PPM_PWR_SRC,
+		.end   = WM831X_IRQ_PPM_PWR_SRC,
+		.flags = IORESOURCE_IRQ,
+	},
+	{
+		.name = "USB CURR",
+		.start = WM831X_IRQ_PPM_USB_CURR,
+		.end   = WM831X_IRQ_PPM_USB_CURR,
+		.flags = IORESOURCE_IRQ,
+	},
+	{
+		.name = "BATT HOT",
+		.start = WM831X_IRQ_CHG_BATT_HOT,
+		.end   = WM831X_IRQ_CHG_BATT_HOT,
+		.flags = IORESOURCE_IRQ,
+	},
+	{
+		.name = "BATT COLD",
+		.start = WM831X_IRQ_CHG_BATT_COLD,
+		.end   = WM831X_IRQ_CHG_BATT_COLD,
+		.flags = IORESOURCE_IRQ,
+	},
+	{
+		.name = "BATT FAIL",
+		.start = WM831X_IRQ_CHG_BATT_FAIL,
+		.end   = WM831X_IRQ_CHG_BATT_FAIL,
+		.flags = IORESOURCE_IRQ,
+	},
+	{
+		.name = "OV",
+		.start = WM831X_IRQ_CHG_OV,
+		.end   = WM831X_IRQ_CHG_OV,
+		.flags = IORESOURCE_IRQ,
+	},
+	{
+		.name = "END",
+		.start = WM831X_IRQ_CHG_END,
+		.end   = WM831X_IRQ_CHG_END,
+		.flags = IORESOURCE_IRQ,
+	},
+	{
+		.name = "TO",
+		.start = WM831X_IRQ_CHG_TO,
+		.end   = WM831X_IRQ_CHG_TO,
+		.flags = IORESOURCE_IRQ,
+	},
+	{
+		.name = "MODE",
+		.start = WM831X_IRQ_CHG_MODE,
+		.end   = WM831X_IRQ_CHG_MODE,
+		.flags = IORESOURCE_IRQ,
+	},
+	{
+		.name = "START",
+		.start = WM831X_IRQ_CHG_START,
+		.end   = WM831X_IRQ_CHG_START,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_rtc_resources[] = {
+	{
+		.name = "PER",
+		.start = WM831X_IRQ_RTC_PER,
+		.end   = WM831X_IRQ_RTC_PER,
+		.flags = IORESOURCE_IRQ,
+	},
+	{
+		.name = "ALM",
+		.start = WM831X_IRQ_RTC_ALM,
+		.end   = WM831X_IRQ_RTC_ALM,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_status1_resources[] = {
+	{
+		.start = WM831X_STATUS_LED_1,
+		.end   = WM831X_STATUS_LED_1,
+		.flags = IORESOURCE_IO,
+	},
+};
+
+static struct resource wm831x_status2_resources[] = {
+	{
+		.start = WM831X_STATUS_LED_2,
+		.end   = WM831X_STATUS_LED_2,
+		.flags = IORESOURCE_IO,
+	},
+};
+
+static struct resource wm831x_touch_resources[] = {
+	{
+		.name = "TCHPD",
+		.start = WM831X_IRQ_TCHPD,
+		.end   = WM831X_IRQ_TCHPD,
+		.flags = IORESOURCE_IRQ,
+	},
+	{
+		.name = "TCHDATA",
+		.start = WM831X_IRQ_TCHDATA,
+		.end   = WM831X_IRQ_TCHDATA,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct resource wm831x_wdt_resources[] = {
+	{
+		.start = WM831X_IRQ_WDOG_TO,
+		.end   = WM831X_IRQ_WDOG_TO,
+		.flags = IORESOURCE_IRQ,
+	},
+};
+
+static struct mfd_cell wm8310_devs[] = {
+	{
+		.name = "wm831x-buckv",
+		.id = 1,
+		.num_resources = ARRAY_SIZE(wm831x_dcdc1_resources),
+		.resources = wm831x_dcdc1_resources,
+	},
+	{
+		.name = "wm831x-buckv",
+		.id = 2,
+		.num_resources = ARRAY_SIZE(wm831x_dcdc2_resources),
+		.resources = wm831x_dcdc2_resources,
+	},
+	{
+		.name = "wm831x-buckp",
+		.id = 3,
+		.num_resources = ARRAY_SIZE(wm831x_dcdc3_resources),
+		.resources = wm831x_dcdc3_resources,
+	},
+	{
+		.name = "wm831x-boostp",
+		.id = 4,
+		.num_resources = ARRAY_SIZE(wm831x_dcdc4_resources),
+		.resources = wm831x_dcdc4_resources,
+	},
+	{
+		.name = "wm831x-epe",
+		.id = 1,
+	},
+	{
+		.name = "wm831x-epe",
+		.id = 2,
+	},
+	{
+		.name = "wm831x-gpio",
+		.num_resources = ARRAY_SIZE(wm831x_gpio_resources),
+		.resources = wm831x_gpio_resources,
+	},
+	{
+		.name = "wm831x-hwmon",
+	},
+	{
+		.name = "wm831x-isink",
+		.id = 1,
+		.num_resources = ARRAY_SIZE(wm831x_isink1_resources),
+		.resources = wm831x_isink1_resources,
+	},
+	{
+		.name = "wm831x-isink",
+		.id = 2,
+		.num_resources = ARRAY_SIZE(wm831x_isink2_resources),
+		.resources = wm831x_isink2_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 1,
+		.num_resources = ARRAY_SIZE(wm831x_ldo1_resources),
+		.resources = wm831x_ldo1_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 2,
+		.num_resources = ARRAY_SIZE(wm831x_ldo2_resources),
+		.resources = wm831x_ldo2_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 3,
+		.num_resources = ARRAY_SIZE(wm831x_ldo3_resources),
+		.resources = wm831x_ldo3_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 4,
+		.num_resources = ARRAY_SIZE(wm831x_ldo4_resources),
+		.resources = wm831x_ldo4_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 5,
+		.num_resources = ARRAY_SIZE(wm831x_ldo5_resources),
+		.resources = wm831x_ldo5_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 6,
+		.num_resources = ARRAY_SIZE(wm831x_ldo6_resources),
+		.resources = wm831x_ldo6_resources,
+	},
+	{
+		.name = "wm831x-aldo",
+		.id = 7,
+		.num_resources = ARRAY_SIZE(wm831x_ldo7_resources),
+		.resources = wm831x_ldo7_resources,
+	},
+	{
+		.name = "wm831x-aldo",
+		.id = 8,
+		.num_resources = ARRAY_SIZE(wm831x_ldo8_resources),
+		.resources = wm831x_ldo8_resources,
+	},
+	{
+		.name = "wm831x-aldo",
+		.id = 9,
+		.num_resources = ARRAY_SIZE(wm831x_ldo9_resources),
+		.resources = wm831x_ldo9_resources,
+	},
+	{
+		.name = "wm831x-aldo",
+		.id = 10,
+		.num_resources = ARRAY_SIZE(wm831x_ldo10_resources),
+		.resources = wm831x_ldo10_resources,
+	},
+	{
+		.name = "wm831x-alive-ldo",
+		.id = 11,
+		.num_resources = ARRAY_SIZE(wm831x_ldo11_resources),
+		.resources = wm831x_ldo11_resources,
+	},
+	{
+		.name = "wm831x-on",
+		.num_resources = ARRAY_SIZE(wm831x_on_resources),
+		.resources = wm831x_on_resources,
+	},
+	{
+		.name = "wm831x-power",
+		.num_resources = ARRAY_SIZE(wm831x_power_resources),
+		.resources = wm831x_power_resources,
+	},
+	{
+		.name = "wm831x-rtc",
+		.num_resources = ARRAY_SIZE(wm831x_rtc_resources),
+		.resources = wm831x_rtc_resources,
+	},
+	{
+		.name = "wm831x-status",
+		.id = 1,
+		.num_resources = ARRAY_SIZE(wm831x_status1_resources),
+		.resources = wm831x_status1_resources,
+	},
+	{
+		.name = "wm831x-status",
+		.id = 2,
+		.num_resources = ARRAY_SIZE(wm831x_status2_resources),
+		.resources = wm831x_status2_resources,
+	},
+	{
+		.name = "wm831x-watchdog",
+		.num_resources = ARRAY_SIZE(wm831x_wdt_resources),
+		.resources = wm831x_wdt_resources,
+	},
+};
+
+static struct mfd_cell wm8311_devs[] = {
+	{
+		.name = "wm831x-buckv",
+		.id = 1,
+		.num_resources = ARRAY_SIZE(wm831x_dcdc1_resources),
+		.resources = wm831x_dcdc1_resources,
+	},
+	{
+		.name = "wm831x-buckv",
+		.id = 2,
+		.num_resources = ARRAY_SIZE(wm831x_dcdc2_resources),
+		.resources = wm831x_dcdc2_resources,
+	},
+	{
+		.name = "wm831x-buckp",
+		.id = 3,
+		.num_resources = ARRAY_SIZE(wm831x_dcdc3_resources),
+		.resources = wm831x_dcdc3_resources,
+	},
+	{
+		.name = "wm831x-boostp",
+		.id = 4,
+		.num_resources = ARRAY_SIZE(wm831x_dcdc4_resources),
+		.resources = wm831x_dcdc4_resources,
+	},
+	{
+		.name = "wm831x-epe",
+		.id = 1,
+	},
+	{
+		.name = "wm831x-epe",
+		.id = 2,
+	},
+	{
+		.name = "wm831x-gpio",
+		.num_resources = ARRAY_SIZE(wm831x_gpio_resources),
+		.resources = wm831x_gpio_resources,
+	},
+	{
+		.name = "wm831x-hwmon",
+	},
+	{
+		.name = "wm831x-isink",
+		.id = 1,
+		.num_resources = ARRAY_SIZE(wm831x_isink1_resources),
+		.resources = wm831x_isink1_resources,
+	},
+	{
+		.name = "wm831x-isink",
+		.id = 2,
+		.num_resources = ARRAY_SIZE(wm831x_isink2_resources),
+		.resources = wm831x_isink2_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 1,
+		.num_resources = ARRAY_SIZE(wm831x_ldo1_resources),
+		.resources = wm831x_ldo1_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 2,
+		.num_resources = ARRAY_SIZE(wm831x_ldo2_resources),
+		.resources = wm831x_ldo2_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 3,
+		.num_resources = ARRAY_SIZE(wm831x_ldo3_resources),
+		.resources = wm831x_ldo3_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 4,
+		.num_resources = ARRAY_SIZE(wm831x_ldo4_resources),
+		.resources = wm831x_ldo4_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 5,
+		.num_resources = ARRAY_SIZE(wm831x_ldo5_resources),
+		.resources = wm831x_ldo5_resources,
+	},
+	{
+		.name = "wm831x-aldo",
+		.id = 7,
+		.num_resources = ARRAY_SIZE(wm831x_ldo7_resources),
+		.resources = wm831x_ldo7_resources,
+	},
+	{
+		.name = "wm831x-alive-ldo",
+		.id = 11,
+		.num_resources = ARRAY_SIZE(wm831x_ldo11_resources),
+		.resources = wm831x_ldo11_resources,
+	},
+	{
+		.name = "wm831x-on",
+		.num_resources = ARRAY_SIZE(wm831x_on_resources),
+		.resources = wm831x_on_resources,
+	},
+	{
+		.name = "wm831x-power",
+		.num_resources = ARRAY_SIZE(wm831x_power_resources),
+		.resources = wm831x_power_resources,
+	},
+	{
+		.name = "wm831x-rtc",
+		.num_resources = ARRAY_SIZE(wm831x_rtc_resources),
+		.resources = wm831x_rtc_resources,
+	},
+	{
+		.name = "wm831x-status",
+		.id = 1,
+		.num_resources = ARRAY_SIZE(wm831x_status1_resources),
+		.resources = wm831x_status1_resources,
+	},
+	{
+		.name = "wm831x-status",
+		.id = 2,
+		.num_resources = ARRAY_SIZE(wm831x_status2_resources),
+		.resources = wm831x_status2_resources,
+	},
+	{
+		.name = "wm831x-touch",
+		.num_resources = ARRAY_SIZE(wm831x_touch_resources),
+		.resources = wm831x_touch_resources,
+	},
+	{
+		.name = "wm831x-watchdog",
+		.num_resources = ARRAY_SIZE(wm831x_wdt_resources),
+		.resources = wm831x_wdt_resources,
+	},
+};
+
+static struct mfd_cell wm8312_devs[] = {
+	{
+		.name = "wm831x-buckv",
+		.id = 1,
+		.num_resources = ARRAY_SIZE(wm831x_dcdc1_resources),
+		.resources = wm831x_dcdc1_resources,
+	},
+	{
+		.name = "wm831x-buckv",
+		.id = 2,
+		.num_resources = ARRAY_SIZE(wm831x_dcdc2_resources),
+		.resources = wm831x_dcdc2_resources,
+	},
+	{
+		.name = "wm831x-buckp",
+		.id = 3,
+		.num_resources = ARRAY_SIZE(wm831x_dcdc3_resources),
+		.resources = wm831x_dcdc3_resources,
+	},
+	{
+		.name = "wm831x-boostp",
+		.id = 4,
+		.num_resources = ARRAY_SIZE(wm831x_dcdc4_resources),
+		.resources = wm831x_dcdc4_resources,
+	},
+	{
+		.name = "wm831x-epe",
+		.id = 1,
+	},
+	{
+		.name = "wm831x-epe",
+		.id = 2,
+	},
+	{
+		.name = "wm831x-gpio",
+		.num_resources = ARRAY_SIZE(wm831x_gpio_resources),
+		.resources = wm831x_gpio_resources,
+	},
+	{
+		.name = "wm831x-hwmon",
+	},
+	{
+		.name = "wm831x-isink",
+		.id = 1,
+		.num_resources = ARRAY_SIZE(wm831x_isink1_resources),
+		.resources = wm831x_isink1_resources,
+	},
+	{
+		.name = "wm831x-isink",
+		.id = 2,
+		.num_resources = ARRAY_SIZE(wm831x_isink2_resources),
+		.resources = wm831x_isink2_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 1,
+		.num_resources = ARRAY_SIZE(wm831x_ldo1_resources),
+		.resources = wm831x_ldo1_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 2,
+		.num_resources = ARRAY_SIZE(wm831x_ldo2_resources),
+		.resources = wm831x_ldo2_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 3,
+		.num_resources = ARRAY_SIZE(wm831x_ldo3_resources),
+		.resources = wm831x_ldo3_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 4,
+		.num_resources = ARRAY_SIZE(wm831x_ldo4_resources),
+		.resources = wm831x_ldo4_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 5,
+		.num_resources = ARRAY_SIZE(wm831x_ldo5_resources),
+		.resources = wm831x_ldo5_resources,
+	},
+	{
+		.name = "wm831x-ldo",
+		.id = 6,
+		.num_resources = ARRAY_SIZE(wm831x_ldo6_resources),
+		.resources = wm831x_ldo6_resources,
+	},
+	{
+		.name = "wm831x-aldo",
+		.id = 7,
+		.num_resources = ARRAY_SIZE(wm831x_ldo7_resources),
+		.resources = wm831x_ldo7_resources,
+	},
+	{
+		.name = "wm831x-aldo",
+		.id = 8,
+		.num_resources = ARRAY_SIZE(wm831x_ldo8_resources),
+		.resources = wm831x_ldo8_resources,
+	},
+	{
+		.name = "wm831x-aldo",
+		.id = 9,
+		.num_resources = ARRAY_SIZE(wm831x_ldo9_resources),
+		.resources = wm831x_ldo9_resources,
+	},
+	{
+		.name = "wm831x-aldo",
+		.id = 10,
+		.num_resources = ARRAY_SIZE(wm831x_ldo10_resources),
+		.resources = wm831x_ldo10_resources,
+	},
+	{
+		.name = "wm831x-alive-ldo",
+		.id = 11,
+		.num_resources = ARRAY_SIZE(wm831x_ldo11_resources),
+		.resources = wm831x_ldo11_resources,
+	},
+	{
+		.name = "wm831x-on",
+		.num_resources = ARRAY_SIZE(wm831x_on_resources),
+		.resources = wm831x_on_resources,
+	},
+	{
+		.name = "wm831x-power",
+		.num_resources = ARRAY_SIZE(wm831x_power_resources),
+		.resources = wm831x_power_resources,
+	},
+	{
+		.name = "wm831x-rtc",
+		.num_resources = ARRAY_SIZE(wm831x_rtc_resources),
+		.resources = wm831x_rtc_resources,
+	},
+	{
+		.name = "wm831x-status",
+		.id = 1,
+		.num_resources = ARRAY_SIZE(wm831x_status1_resources),
+		.resources = wm831x_status1_resources,
+	},
+	{
+		.name = "wm831x-status",
+		.id = 2,
+		.num_resources = ARRAY_SIZE(wm831x_status2_resources),
+		.resources = wm831x_status2_resources,
+	},
+	{
+		.name = "wm831x-touch",
+		.num_resources = ARRAY_SIZE(wm831x_touch_resources),
+		.resources = wm831x_touch_resources,
+	},
+	{
+		.name = "wm831x-watchdog",
+		.num_resources = ARRAY_SIZE(wm831x_wdt_resources),
+		.resources = wm831x_wdt_resources,
+	},
+};
+
+/*
+ * Instantiate the generic non-control parts of the device.
+ */
+static int wm831x_device_init(struct wm831x *wm831x, unsigned long id, int irq)
+{
+	struct wm831x_pdata *pdata = wm831x->dev->platform_data;
+	int rev;
+	enum wm831x_parent parent;
+	int ret;
+
+	mutex_init(&wm831x->io_lock);
+	mutex_init(&wm831x->key_lock);
+	dev_set_drvdata(wm831x->dev, wm831x);
+
+	ret = wm831x_reg_read(wm831x, WM831X_PARENT_ID);
+	if (ret < 0) {
+		dev_err(wm831x->dev, "Failed to read parent ID: %d\n", ret);
+		goto err;
+	}
+	if (ret != 0x6204) {
+		dev_err(wm831x->dev, "Device is not a WM831x: ID %x\n", ret);
+		ret = -EINVAL;
+		goto err;
+	}
+
+	ret = wm831x_reg_read(wm831x, WM831X_REVISION);
+	if (ret < 0) {
+		dev_err(wm831x->dev, "Failed to read revision: %d\n", ret);
+		goto err;
+	}
+	rev = (ret & WM831X_PARENT_REV_MASK) >> WM831X_PARENT_REV_SHIFT;
+
+	ret = wm831x_reg_read(wm831x, WM831X_RESET_ID);
+	if (ret < 0) {
+		dev_err(wm831x->dev, "Failed to read device ID: %d\n", ret);
+		goto err;
+	}
+
+	switch (ret) {
+	case 0x8310:
+		parent = WM8310;
+		switch (rev) {
+		case 0:
+			dev_info(wm831x->dev, "WM8310 revision %c\n",
+				 'A' + rev);
+			break;
+		}
+		break;
+
+	case 0x8311:
+		parent = WM8311;
+		switch (rev) {
+		case 0:
+			dev_info(wm831x->dev, "WM8311 revision %c\n",
+				 'A' + rev);
+			break;
+		}
+		break;
+
+	case 0x8312:
+		parent = WM8312;
+		switch (rev) {
+		case 0:
+			dev_info(wm831x->dev, "WM8312 revision %c\n",
+				 'A' + rev);
+			break;
+		}
+		break;
+
+	case 0:
+		/* Some engineering samples do not have the ID set,
+		 * rely on the device being registered correctly.
+		 * This will need revisiting for future devices with
+		 * multiple dies.
+		 */
+		parent = id;
+		switch (rev) {
+		case 0:
+			dev_info(wm831x->dev, "WM831%d ES revision %c\n",
+				 parent, 'A' + rev);
+			break;
+		}
+		break;
+
+	default:
+		dev_err(wm831x->dev, "Unknown WM831x device %04x\n", ret);
+		ret = -EINVAL;
+		goto err;
+	}
+
+	/* This will need revisiting in future but is OK for all
+	 * current parts.
+	 */
+	if (parent != id)
+		dev_warn(wm831x->dev, "Device was registered as a WM831%lu\n",
+			 id);
+
+	/* Bootstrap the user key */
+	ret = wm831x_reg_read(wm831x, WM831X_SECURITY_KEY);
+	if (ret < 0) {
+		dev_err(wm831x->dev, "Failed to read security key: %d\n", ret);
+		goto err;
+	}
+	if (ret != 0) {
+		dev_warn(wm831x->dev, "Security key had non-zero value %x\n",
+			 ret);
+		wm831x_reg_write(wm831x, WM831X_SECURITY_KEY, 0);
+	}
+	wm831x->locked = 1;
+
+	if (pdata && pdata->pre_init) {
+		ret = pdata->pre_init(wm831x);
+		if (ret != 0) {
+			dev_err(wm831x->dev, "pre_init() failed: %d\n", ret);
+			goto err;
+		}
+	}
+
+	/* The core device is up, instantiate the subdevices. */
+	switch (parent) {
+	case WM8310:
+		ret = mfd_add_devices(wm831x->dev, -1,
+				      wm8310_devs, ARRAY_SIZE(wm8310_devs),
+				      NULL, 0);
+		break;
+
+	case WM8311:
+		ret = mfd_add_devices(wm831x->dev, -1,
+				      wm8311_devs, ARRAY_SIZE(wm8311_devs),
+				      NULL, 0);
+		break;
+
+	case WM8312:
+		ret = mfd_add_devices(wm831x->dev, -1,
+				      wm8312_devs, ARRAY_SIZE(wm8312_devs),
+				      NULL, 0);
+		break;
+
+	default:
+		/* If this happens the bus probe function is buggy */
+		BUG();
+	}
+
+	if (ret != 0) {
+		dev_err(wm831x->dev, "Failed to add children\n");
+		goto err;
+	}
+
+	if (pdata && pdata->post_init) {
+		ret = pdata->post_init(wm831x);
+		if (ret != 0) {
+			dev_err(wm831x->dev, "post_init() failed: %d\n", ret);
+			goto err;
+		}
+	}
+
+	return 0;
+
+err:
+	mfd_remove_devices(wm831x->dev);
+	kfree(wm831x);
+	return ret;
+}
+
+static void wm831x_device_exit(struct wm831x *wm831x)
+{
+	mfd_remove_devices(wm831x->dev);
+	kfree(wm831x);
+}
+
+static int wm831x_i2c_read_device(struct wm831x *wm831x, unsigned short reg,
+				  int bytes, void *dest)
+{
+	struct i2c_client *i2c = wm831x->control_data;
+	int ret;
+	u16 r = cpu_to_be16(reg);
+
+	ret = i2c_master_send(i2c, (unsigned char *)&r, 2);
+	if (ret < 0)
+		return ret;
+	if (ret != 2)
+		return -EIO;
+
+	ret = i2c_master_recv(i2c, dest, bytes);
+	if (ret < 0)
+		return ret;
+	if (ret != bytes)
+		return -EIO;
+	return 0;
+}
+
+/* Currently we allocate the write buffer on the stack; this is OK for
+ * small writes - if we need to do large writes this will need to be
+ * revised.
+ */
+static int wm831x_i2c_write_device(struct wm831x *wm831x, unsigned short reg,
+				   int bytes, void *src)
+{
+	struct i2c_client *i2c = wm831x->control_data;
+	unsigned char msg[bytes + 2];
+	int ret;
+
+	reg = cpu_to_be16(reg);
+	memcpy(&msg[0], &reg, 2);
+	memcpy(&msg[2], src, bytes);
+
+	ret = i2c_master_send(i2c, msg, bytes + 2);
+	if (ret < 0)
+		return ret;
+	if (ret < bytes + 2)
+		return -EIO;
+
+	return 0;
+}
+
+static int wm831x_i2c_probe(struct i2c_client *i2c,
+			    const struct i2c_device_id *id)
+{
+	struct wm831x *wm831x;
+
+	wm831x = kzalloc(sizeof(struct wm831x), GFP_KERNEL);
+	if (wm831x == NULL) {
+		kfree(i2c);
+		return -ENOMEM;
+	}
+
+	i2c_set_clientdata(i2c, wm831x);
+	wm831x->dev = &i2c->dev;
+	wm831x->control_data = i2c;
+	wm831x->read_dev = wm831x_i2c_read_device;
+	wm831x->write_dev = wm831x_i2c_write_device;
+
+	return wm831x_device_init(wm831x, id->driver_data, i2c->irq);
+}
+
+static int wm831x_i2c_remove(struct i2c_client *i2c)
+{
+	struct wm831x *wm831x = i2c_get_clientdata(i2c);
+
+	wm831x_device_exit(wm831x);
+
+	return 0;
+}
+
+static const struct i2c_device_id wm831x_i2c_id[] = {
+	{ "wm8310", WM8310 },
+	{ "wm8311", WM8311 },
+	{ "wm8312", WM8312 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, wm831x_i2c_id);
+
+
+static struct i2c_driver wm831x_i2c_driver = {
+	.driver = {
+		   .name = "wm831x",
+		   .owner = THIS_MODULE,
+	},
+	.probe = wm831x_i2c_probe,
+	.remove = wm831x_i2c_remove,
+	.id_table = wm831x_i2c_id,
+};
+
+static int __init wm831x_i2c_init(void)
+{
+	int ret;
+
+	ret = i2c_add_driver(&wm831x_i2c_driver);
+	if (ret != 0)
+		pr_err("Failed to register wm831x I2C driver: %d\n", ret);
+
+	return ret;
+}
+subsys_initcall(wm831x_i2c_init);
+
+static void __exit wm831x_i2c_exit(void)
+{
+	i2c_del_driver(&wm831x_i2c_driver);
+}
+module_exit(wm831x_i2c_exit);
+
+MODULE_DESCRIPTION("I2C support for the WM831X AudioPlus PMIC");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mark Brown");