drivers/mfd/wm8350-core.c - maze/linux - Git at Google

 /*
  * wm8350-core.c  --  Device access for Wolfson WM8350
  *
  * Copyright 2007, 2008 Wolfson Microelectronics PLC.
  *
  * Author: Liam Girdwood, Mark Brown
  *
  *  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/init.h>
 #include <linux/device.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>

 #include <linux/mfd/wm8350/core.h>
 #include <linux/mfd/wm8350/audio.h>
 #include <linux/mfd/wm8350/gpio.h>
 #include <linux/mfd/wm8350/pmic.h>
 #include <linux/mfd/wm8350/supply.h>

 #define WM8350_UNLOCK_KEY		0x0013
 #define WM8350_LOCK_KEY			0x0000

 #define WM8350_CLOCK_CONTROL_1		0x28
 #define WM8350_AIF_TEST			0x74

 /* debug */
 #define WM8350_BUS_DEBUG 0
 #if WM8350_BUS_DEBUG
 #define dump(regs, src) do { \
 	int i_; \
 	u16 *src_ = src; \
 	printk(KERN_DEBUG); \
 	for (i_ = 0; i_ < regs; i_++) \
 		printk(" 0x%4.4x", *src_++); \
 	printk("\n"); \
 } while (0);
 #else
 #define dump(bytes, src)
 #endif

 #define WM8350_LOCK_DEBUG 0
 #if WM8350_LOCK_DEBUG
 #define ldbg(format, arg...) printk(format, ## arg)
 #else
 #define ldbg(format, arg...)
 #endif

 /*
  * WM8350 Device IO
  */
 static DEFINE_MUTEX(io_mutex);
 static DEFINE_MUTEX(reg_lock_mutex);
 static DEFINE_MUTEX(auxadc_mutex);

 /* Perform a physical read from the device.
  */
 static int wm8350_phys_read(struct wm8350 *wm8350, u8 reg, int num_regs,
 			    u16 *dest)
 {
 	int i, ret;
 	int bytes = num_regs * 2;

 	dev_dbg(wm8350->dev, "volatile read\n");
 	ret = wm8350->read_dev(wm8350, reg, bytes, (char *)dest);

 	for (i = reg; i < reg + num_regs; i++) {
 		/* Cache is CPU endian */
 		dest[i - reg] = be16_to_cpu(dest[i - reg]);

 		/* Satisfy non-volatile bits from cache */
 		dest[i - reg] &= wm8350_reg_io_map[i].vol;
 		dest[i - reg] |= wm8350->reg_cache[i];

 		/* Mask out non-readable bits */
 		dest[i - reg] &= wm8350_reg_io_map[i].readable;
 	}

 	dump(num_regs, dest);

 	return ret;
 }

 static int wm8350_read(struct wm8350 *wm8350, u8 reg, int num_regs, u16 *dest)
 {
 	int i;
 	int end = reg + num_regs;
 	int ret = 0;
 	int bytes = num_regs * 2;

 	if (wm8350->read_dev == NULL)
 		return -ENODEV;

 	if ((reg + num_regs - 1) > WM8350_MAX_REGISTER) {
 		dev_err(wm8350->dev, "invalid reg %x\n",
 			reg + num_regs - 1);
 		return -EINVAL;
 	}

 	dev_dbg(wm8350->dev,
 		"%s R%d(0x%2.2x) %d regs\n", __func__, reg, reg, num_regs);

 #if WM8350_BUS_DEBUG
 	/* we can _safely_ read any register, but warn if read not supported */
 	for (i = reg; i < end; i++) {
 		if (!wm8350_reg_io_map[i].readable)
 			dev_warn(wm8350->dev,
 				"reg R%d is not readable\n", i);
 	}
 #endif

 	/* if any volatile registers are required, then read back all */
 	for (i = reg; i < end; i++)
 		if (wm8350_reg_io_map[i].vol)
 			return wm8350_phys_read(wm8350, reg, num_regs, dest);

 	/* no volatiles, then cache is good */
 	dev_dbg(wm8350->dev, "cache read\n");
 	memcpy(dest, &wm8350->reg_cache[reg], bytes);
 	dump(num_regs, dest);
 	return ret;
 }

 static inline int is_reg_locked(struct wm8350 *wm8350, u8 reg)
 {
 	if (reg == WM8350_SECURITY ||
 	    wm8350->reg_cache[WM8350_SECURITY] == WM8350_UNLOCK_KEY)
 		return 0;

 	if ((reg == WM8350_GPIO_CONFIGURATION_I_O) ||
 	    (reg >= WM8350_GPIO_FUNCTION_SELECT_1 &&
 	     reg <= WM8350_GPIO_FUNCTION_SELECT_4) ||
 	    (reg >= WM8350_BATTERY_CHARGER_CONTROL_1 &&
 	     reg <= WM8350_BATTERY_CHARGER_CONTROL_3))
 		return 1;
 	return 0;
 }

 static int wm8350_write(struct wm8350 *wm8350, u8 reg, int num_regs, u16 *src)
 {
 	int i;
 	int end = reg + num_regs;
 	int bytes = num_regs * 2;

 	if (wm8350->write_dev == NULL)
 		return -ENODEV;

 	if ((reg + num_regs - 1) > WM8350_MAX_REGISTER) {
 		dev_err(wm8350->dev, "invalid reg %x\n",
 			reg + num_regs - 1);
 		return -EINVAL;
 	}

 	/* it's generally not a good idea to write to RO or locked registers */
 	for (i = reg; i < end; i++) {
 		if (!wm8350_reg_io_map[i].writable) {
 			dev_err(wm8350->dev,
 				"attempted write to read only reg R%d\n", i);
 			return -EINVAL;
 		}

 		if (is_reg_locked(wm8350, i)) {
 			dev_err(wm8350->dev,
 			       "attempted write to locked reg R%d\n", i);
 			return -EINVAL;
 		}

 		src[i - reg] &= wm8350_reg_io_map[i].writable;

 		wm8350->reg_cache[i] =
 			(wm8350->reg_cache[i] & ~wm8350_reg_io_map[i].writable)
 			| src[i - reg];

 		src[i - reg] = cpu_to_be16(src[i - reg]);
 	}

 	/* Actually write it out */
 	return wm8350->write_dev(wm8350, reg, bytes, (char *)src);
 }

 /*
  * Safe read, modify, write methods
  */
 int wm8350_clear_bits(struct wm8350 *wm8350, u16 reg, u16 mask)
 {
 	u16 data;
 	int err;

 	mutex_lock(&io_mutex);
 	err = wm8350_read(wm8350, reg, 1, &data);
 	if (err) {
 		dev_err(wm8350->dev, "read from reg R%d failed\n", reg);
 		goto out;
 	}

 	data &= ~mask;
 	err = wm8350_write(wm8350, reg, 1, &data);
 	if (err)
 		dev_err(wm8350->dev, "write to reg R%d failed\n", reg);
 out:
 	mutex_unlock(&io_mutex);
 	return err;
 }
 EXPORT_SYMBOL_GPL(wm8350_clear_bits);

 int wm8350_set_bits(struct wm8350 *wm8350, u16 reg, u16 mask)
 {
 	u16 data;
 	int err;

 	mutex_lock(&io_mutex);
 	err = wm8350_read(wm8350, reg, 1, &data);
 	if (err) {
 		dev_err(wm8350->dev, "read from reg R%d failed\n", reg);
 		goto out;
 	}

 	data |= mask;
 	err = wm8350_write(wm8350, reg, 1, &data);
 	if (err)
 		dev_err(wm8350->dev, "write to reg R%d failed\n", reg);
 out:
 	mutex_unlock(&io_mutex);
 	return err;
 }
 EXPORT_SYMBOL_GPL(wm8350_set_bits);

 u16 wm8350_reg_read(struct wm8350 *wm8350, int reg)
 {
 	u16 data;
 	int err;

 	mutex_lock(&io_mutex);
 	err = wm8350_read(wm8350, reg, 1, &data);
 	if (err)
 		dev_err(wm8350->dev, "read from reg R%d failed\n", reg);

 	mutex_unlock(&io_mutex);
 	return data;
 }
 EXPORT_SYMBOL_GPL(wm8350_reg_read);

 int wm8350_reg_write(struct wm8350 *wm8350, int reg, u16 val)
 {
 	int ret;
 	u16 data = val;

 	mutex_lock(&io_mutex);
 	ret = wm8350_write(wm8350, reg, 1, &data);
 	if (ret)
 		dev_err(wm8350->dev, "write to reg R%d failed\n", reg);
 	mutex_unlock(&io_mutex);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(wm8350_reg_write);

 int wm8350_block_read(struct wm8350 *wm8350, int start_reg, int regs,
 		      u16 *dest)
 {
 	int err = 0;

 	mutex_lock(&io_mutex);
 	err = wm8350_read(wm8350, start_reg, regs, dest);
 	if (err)
 		dev_err(wm8350->dev, "block read starting from R%d failed\n",
 			start_reg);
 	mutex_unlock(&io_mutex);
 	return err;
 }
 EXPORT_SYMBOL_GPL(wm8350_block_read);

 int wm8350_block_write(struct wm8350 *wm8350, int start_reg, int regs,
 		       u16 *src)
 {
 	int ret = 0;

 	mutex_lock(&io_mutex);
 	ret = wm8350_write(wm8350, start_reg, regs, src);
 	if (ret)
 		dev_err(wm8350->dev, "block write starting at R%d failed\n",
 			start_reg);
 	mutex_unlock(&io_mutex);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(wm8350_block_write);

 int wm8350_reg_lock(struct wm8350 *wm8350)
 {
 	u16 key = WM8350_LOCK_KEY;
 	int ret;

 	ldbg(__func__);
 	mutex_lock(&io_mutex);
 	ret = wm8350_write(wm8350, WM8350_SECURITY, 1, &key);
 	if (ret)
 		dev_err(wm8350->dev, "lock failed\n");
 	mutex_unlock(&io_mutex);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(wm8350_reg_lock);

 int wm8350_reg_unlock(struct wm8350 *wm8350)
 {
 	u16 key = WM8350_UNLOCK_KEY;
 	int ret;

 	ldbg(__func__);
 	mutex_lock(&io_mutex);
 	ret = wm8350_write(wm8350, WM8350_SECURITY, 1, &key);
 	if (ret)
 		dev_err(wm8350->dev, "unlock failed\n");
 	mutex_unlock(&io_mutex);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(wm8350_reg_unlock);

 /*
  * Cache is always host endian.
  */
 static int wm8350_create_cache(struct wm8350 *wm8350, int mode)
 {
 	int i, ret = 0;
 	u16 value;
 	const u16 *reg_map;

 	switch (mode) {
 #ifdef CONFIG_MFD_WM8350_CONFIG_MODE_0
 	case 0:
 		reg_map = wm8350_mode0_defaults;
 		break;
 #endif
 #ifdef CONFIG_MFD_WM8350_CONFIG_MODE_1
 	case 1:
 		reg_map = wm8350_mode1_defaults;
 		break;
 #endif
 #ifdef CONFIG_MFD_WM8350_CONFIG_MODE_2
 	case 2:
 		reg_map = wm8350_mode2_defaults;
 		break;
 #endif
 #ifdef CONFIG_MFD_WM8350_CONFIG_MODE_3
 	case 3:
 		reg_map = wm8350_mode3_defaults;
 		break;
 #endif
 	default:
 		dev_err(wm8350->dev, "Configuration mode %d not supported\n",
 			mode);
 		return -EINVAL;
 	}

 	wm8350->reg_cache =
 	    kzalloc(sizeof(u16) * (WM8350_MAX_REGISTER + 1), GFP_KERNEL);
 	if (wm8350->reg_cache == NULL)
 		return -ENOMEM;

 	/* Read the initial cache state back from the device - this is
 	 * a PMIC so the device many not be in a virgin state and we
 	 * can't rely on the silicon values.
 	 */
 	for (i = 0; i < WM8350_MAX_REGISTER; i++) {
 		/* audio register range */
 		if (wm8350_reg_io_map[i].readable &&
 		    (i < WM8350_CLOCK_CONTROL_1 || i > WM8350_AIF_TEST)) {
 			ret = wm8350->read_dev(wm8350, i, 2, (char *)&value);
 			if (ret < 0) {
 				dev_err(wm8350->dev,
 				       "failed to read initial cache value\n");
 				goto out;
 			}
 			value = be16_to_cpu(value);
 			value &= wm8350_reg_io_map[i].readable;
 			wm8350->reg_cache[i] = value;
 		} else
 			wm8350->reg_cache[i] = reg_map[i];
 	}

 out:
 	return ret;
 }
 EXPORT_SYMBOL_GPL(wm8350_create_cache);

 int wm8350_device_init(struct wm8350 *wm8350,
 		       struct wm8350_platform_data *pdata)
 {
 	int ret = -EINVAL;
 	u16 id1, id2, mask, mode;

 	/* get WM8350 revision and config mode */
 	wm8350->read_dev(wm8350, WM8350_RESET_ID, sizeof(id1), &id1);
 	wm8350->read_dev(wm8350, WM8350_ID, sizeof(id2), &id2);

 	id1 = be16_to_cpu(id1);
 	id2 = be16_to_cpu(id2);

 	if (id1 == 0x0)
 		dev_info(wm8350->dev, "Found Rev C device\n");
 	else if (id1 == 0x6143) {
 		switch ((id2 & WM8350_CHIP_REV_MASK) >> 12) {
 		case WM8350_REV_E:
 			dev_info(wm8350->dev, "Found Rev E device\n");
 			wm8350->rev = WM8350_REV_E;
 			break;
 		case WM8350_REV_F:
 			dev_info(wm8350->dev, "Found Rev F device\n");
 			wm8350->rev = WM8350_REV_F;
 			break;
 		case WM8350_REV_G:
 			dev_info(wm8350->dev, "Found Rev G device\n");
 			wm8350->rev = WM8350_REV_G;
 			break;
 		default:
 			/* For safety we refuse to run on unknown hardware */
 			dev_info(wm8350->dev, "Found unknown rev\n");
 			ret = -ENODEV;
 			goto err;
 		}
 	} else {
 		dev_info(wm8350->dev, "Device with ID %x is not a WM8350\n",
 			 id1);
 		ret = -ENODEV;
 		goto err;
 	}

 	mode = id2 & WM8350_CONF_STS_MASK >> 10;
 	mask = id2 & WM8350_CUST_ID_MASK;
 	dev_info(wm8350->dev, "Config mode %d, ROM mask %d\n", mode, mask);

 	ret = wm8350_create_cache(wm8350, mode);
 	if (ret < 0) {
 		printk(KERN_ERR "wm8350: failed to create register cache\n");
 		return ret;
 	}

 	if (pdata->init) {
 		ret = pdata->init(wm8350);
 		if (ret != 0) {
 			dev_err(wm8350->dev, "Platform init() failed: %d\n",
 				ret);
 			goto err;
 		}
 	}

 	return 0;

 err:
 	kfree(wm8350->reg_cache);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(wm8350_device_init);

 void wm8350_device_exit(struct wm8350 *wm8350)
 {
 	kfree(wm8350->reg_cache);
 }
 EXPORT_SYMBOL_GPL(wm8350_device_exit);

 MODULE_LICENSE("GPL");
	/*
	* wm8350-core.c -- Device access for Wolfson WM8350
	*
	* Copyright 2007, 2008 Wolfson Microelectronics PLC.
	*
	* Author: Liam Girdwood, Mark Brown
	*
	* 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/init.h>
	#include <linux/device.h>
	#include <linux/delay.h>
	#include <linux/interrupt.h>

	#include <linux/mfd/wm8350/core.h>
	#include <linux/mfd/wm8350/audio.h>
	#include <linux/mfd/wm8350/gpio.h>
	#include <linux/mfd/wm8350/pmic.h>
	#include <linux/mfd/wm8350/supply.h>

	#define WM8350_UNLOCK_KEY 0x0013
	#define WM8350_LOCK_KEY 0x0000

	#define WM8350_CLOCK_CONTROL_1 0x28
	#define WM8350_AIF_TEST 0x74

	/* debug */
	#define WM8350_BUS_DEBUG 0
	#if WM8350_BUS_DEBUG
	#define dump(regs, src) do { \
	int i_; \
	u16 *src_ = src; \
	printk(KERN_DEBUG); \
	for (i_ = 0; i_ < regs; i_++) \
	printk(" 0x%4.4x", *src_++); \
	printk("\n"); \
	} while (0);
	#else
	#define dump(bytes, src)
	#endif

	#define WM8350_LOCK_DEBUG 0
	#if WM8350_LOCK_DEBUG
	#define ldbg(format, arg...) printk(format, ## arg)
	#else
	#define ldbg(format, arg...)
	#endif

	/*
	* WM8350 Device IO
	*/
	static DEFINE_MUTEX(io_mutex);
	static DEFINE_MUTEX(reg_lock_mutex);
	static DEFINE_MUTEX(auxadc_mutex);

	/* Perform a physical read from the device.
	*/
	static int wm8350_phys_read(struct wm8350 *wm8350, u8 reg, int num_regs,
	u16 *dest)
	{
	int i, ret;
	int bytes = num_regs * 2;

	dev_dbg(wm8350->dev, "volatile read\n");
	ret = wm8350->read_dev(wm8350, reg, bytes, (char *)dest);

	for (i = reg; i < reg + num_regs; i++) {
	/* Cache is CPU endian */
	dest[i - reg] = be16_to_cpu(dest[i - reg]);

	/* Satisfy non-volatile bits from cache */
	dest[i - reg] &= wm8350_reg_io_map[i].vol;
	dest[i - reg] \|= wm8350->reg_cache[i];

	/* Mask out non-readable bits */
	dest[i - reg] &= wm8350_reg_io_map[i].readable;
	}

	dump(num_regs, dest);

	return ret;
	}

	static int wm8350_read(struct wm8350 wm8350, u8 reg, int num_regs, u16 dest)
	{
	int i;
	int end = reg + num_regs;
	int ret = 0;
	int bytes = num_regs * 2;

	if (wm8350->read_dev == NULL)
	return -ENODEV;

	if ((reg + num_regs - 1) > WM8350_MAX_REGISTER) {
	dev_err(wm8350->dev, "invalid reg %x\n",
	reg + num_regs - 1);
	return -EINVAL;
	}

	dev_dbg(wm8350->dev,
	"%s R%d(0x%2.2x) %d regs\n", __func__, reg, reg, num_regs);

	#if WM8350_BUS_DEBUG
	/* we can _safely_ read any register, but warn if read not supported */
	for (i = reg; i < end; i++) {
	if (!wm8350_reg_io_map[i].readable)
	dev_warn(wm8350->dev,
	"reg R%d is not readable\n", i);
	}
	#endif

	/* if any volatile registers are required, then read back all */
	for (i = reg; i < end; i++)
	if (wm8350_reg_io_map[i].vol)
	return wm8350_phys_read(wm8350, reg, num_regs, dest);

	/* no volatiles, then cache is good */
	dev_dbg(wm8350->dev, "cache read\n");
	memcpy(dest, &wm8350->reg_cache[reg], bytes);
	dump(num_regs, dest);
	return ret;
	}

	static inline int is_reg_locked(struct wm8350 *wm8350, u8 reg)
	{
	if (reg == WM8350_SECURITY \|\|
	wm8350->reg_cache[WM8350_SECURITY] == WM8350_UNLOCK_KEY)
	return 0;

	if ((reg == WM8350_GPIO_CONFIGURATION_I_O) \|\|
	(reg >= WM8350_GPIO_FUNCTION_SELECT_1 &&
	reg <= WM8350_GPIO_FUNCTION_SELECT_4) \|\|
	(reg >= WM8350_BATTERY_CHARGER_CONTROL_1 &&
	reg <= WM8350_BATTERY_CHARGER_CONTROL_3))
	return 1;
	return 0;
	}

	static int wm8350_write(struct wm8350 wm8350, u8 reg, int num_regs, u16 src)
	{
	int i;
	int end = reg + num_regs;
	int bytes = num_regs * 2;

	if (wm8350->write_dev == NULL)
	return -ENODEV;

	if ((reg + num_regs - 1) > WM8350_MAX_REGISTER) {
	dev_err(wm8350->dev, "invalid reg %x\n",
	reg + num_regs - 1);
	return -EINVAL;
	}

	/* it's generally not a good idea to write to RO or locked registers */
	for (i = reg; i < end; i++) {
	if (!wm8350_reg_io_map[i].writable) {
	dev_err(wm8350->dev,
	"attempted write to read only reg R%d\n", i);
	return -EINVAL;
	}

	if (is_reg_locked(wm8350, i)) {
	dev_err(wm8350->dev,
	"attempted write to locked reg R%d\n", i);
	return -EINVAL;
	}

	src[i - reg] &= wm8350_reg_io_map[i].writable;

	wm8350->reg_cache[i] =
	(wm8350->reg_cache[i] & ~wm8350_reg_io_map[i].writable)
	\| src[i - reg];

	src[i - reg] = cpu_to_be16(src[i - reg]);
	}

	/* Actually write it out */
	return wm8350->write_dev(wm8350, reg, bytes, (char *)src);
	}

	/*
	* Safe read, modify, write methods
	*/
	int wm8350_clear_bits(struct wm8350 *wm8350, u16 reg, u16 mask)
	{
	u16 data;
	int err;

	mutex_lock(&io_mutex);
	err = wm8350_read(wm8350, reg, 1, &data);
	if (err) {
	dev_err(wm8350->dev, "read from reg R%d failed\n", reg);
	goto out;
	}

	data &= ~mask;
	err = wm8350_write(wm8350, reg, 1, &data);
	if (err)
	dev_err(wm8350->dev, "write to reg R%d failed\n", reg);
	out:
	mutex_unlock(&io_mutex);
	return err;
	}
	EXPORT_SYMBOL_GPL(wm8350_clear_bits);

	int wm8350_set_bits(struct wm8350 *wm8350, u16 reg, u16 mask)
	{
	u16 data;
	int err;

	mutex_lock(&io_mutex);
	err = wm8350_read(wm8350, reg, 1, &data);
	if (err) {
	dev_err(wm8350->dev, "read from reg R%d failed\n", reg);
	goto out;
	}

	data \|= mask;
	err = wm8350_write(wm8350, reg, 1, &data);
	if (err)
	dev_err(wm8350->dev, "write to reg R%d failed\n", reg);
	out:
	mutex_unlock(&io_mutex);
	return err;
	}
	EXPORT_SYMBOL_GPL(wm8350_set_bits);

	u16 wm8350_reg_read(struct wm8350 *wm8350, int reg)
	{
	u16 data;
	int err;

	mutex_lock(&io_mutex);
	err = wm8350_read(wm8350, reg, 1, &data);
	if (err)
	dev_err(wm8350->dev, "read from reg R%d failed\n", reg);

	mutex_unlock(&io_mutex);
	return data;
	}
	EXPORT_SYMBOL_GPL(wm8350_reg_read);

	int wm8350_reg_write(struct wm8350 *wm8350, int reg, u16 val)
	{
	int ret;
	u16 data = val;

	mutex_lock(&io_mutex);
	ret = wm8350_write(wm8350, reg, 1, &data);
	if (ret)
	dev_err(wm8350->dev, "write to reg R%d failed\n", reg);
	mutex_unlock(&io_mutex);
	return ret;
	}
	EXPORT_SYMBOL_GPL(wm8350_reg_write);

	int wm8350_block_read(struct wm8350 *wm8350, int start_reg, int regs,
	u16 *dest)
	{
	int err = 0;

	mutex_lock(&io_mutex);
	err = wm8350_read(wm8350, start_reg, regs, dest);
	if (err)
	dev_err(wm8350->dev, "block read starting from R%d failed\n",
	start_reg);
	mutex_unlock(&io_mutex);
	return err;
	}
	EXPORT_SYMBOL_GPL(wm8350_block_read);

	int wm8350_block_write(struct wm8350 *wm8350, int start_reg, int regs,
	u16 *src)
	{
	int ret = 0;

	mutex_lock(&io_mutex);
	ret = wm8350_write(wm8350, start_reg, regs, src);
	if (ret)
	dev_err(wm8350->dev, "block write starting at R%d failed\n",
	start_reg);
	mutex_unlock(&io_mutex);
	return ret;
	}
	EXPORT_SYMBOL_GPL(wm8350_block_write);

	int wm8350_reg_lock(struct wm8350 *wm8350)
	{
	u16 key = WM8350_LOCK_KEY;
	int ret;

	ldbg(__func__);
	mutex_lock(&io_mutex);
	ret = wm8350_write(wm8350, WM8350_SECURITY, 1, &key);
	if (ret)
	dev_err(wm8350->dev, "lock failed\n");
	mutex_unlock(&io_mutex);
	return ret;
	}
	EXPORT_SYMBOL_GPL(wm8350_reg_lock);

	int wm8350_reg_unlock(struct wm8350 *wm8350)
	{
	u16 key = WM8350_UNLOCK_KEY;
	int ret;

	ldbg(__func__);
	mutex_lock(&io_mutex);
	ret = wm8350_write(wm8350, WM8350_SECURITY, 1, &key);
	if (ret)
	dev_err(wm8350->dev, "unlock failed\n");
	mutex_unlock(&io_mutex);
	return ret;
	}
	EXPORT_SYMBOL_GPL(wm8350_reg_unlock);

	/*
	* Cache is always host endian.
	*/
	static int wm8350_create_cache(struct wm8350 *wm8350, int mode)
	{
	int i, ret = 0;
	u16 value;
	const u16 *reg_map;

	switch (mode) {
	#ifdef CONFIG_MFD_WM8350_CONFIG_MODE_0
	case 0:
	reg_map = wm8350_mode0_defaults;
	break;
	#endif
	#ifdef CONFIG_MFD_WM8350_CONFIG_MODE_1
	case 1:
	reg_map = wm8350_mode1_defaults;
	break;
	#endif
	#ifdef CONFIG_MFD_WM8350_CONFIG_MODE_2
	case 2:
	reg_map = wm8350_mode2_defaults;
	break;
	#endif
	#ifdef CONFIG_MFD_WM8350_CONFIG_MODE_3
	case 3:
	reg_map = wm8350_mode3_defaults;
	break;
	#endif
	default:
	dev_err(wm8350->dev, "Configuration mode %d not supported\n",
	mode);
	return -EINVAL;
	}

	wm8350->reg_cache =
	kzalloc(sizeof(u16) * (WM8350_MAX_REGISTER + 1), GFP_KERNEL);
	if (wm8350->reg_cache == NULL)
	return -ENOMEM;

	/* Read the initial cache state back from the device - this is
	* a PMIC so the device many not be in a virgin state and we
	* can't rely on the silicon values.
	*/
	for (i = 0; i < WM8350_MAX_REGISTER; i++) {
	/* audio register range */
	if (wm8350_reg_io_map[i].readable &&
	(i < WM8350_CLOCK_CONTROL_1 \|\| i > WM8350_AIF_TEST)) {
	ret = wm8350->read_dev(wm8350, i, 2, (char *)&value);
	if (ret < 0) {
	dev_err(wm8350->dev,
	"failed to read initial cache value\n");
	goto out;
	}
	value = be16_to_cpu(value);
	value &= wm8350_reg_io_map[i].readable;
	wm8350->reg_cache[i] = value;
	} else
	wm8350->reg_cache[i] = reg_map[i];
	}

	out:
	return ret;
	}
	EXPORT_SYMBOL_GPL(wm8350_create_cache);

	int wm8350_device_init(struct wm8350 *wm8350,
	struct wm8350_platform_data *pdata)
	{
	int ret = -EINVAL;
	u16 id1, id2, mask, mode;

	/* get WM8350 revision and config mode */
	wm8350->read_dev(wm8350, WM8350_RESET_ID, sizeof(id1), &id1);
	wm8350->read_dev(wm8350, WM8350_ID, sizeof(id2), &id2);

	id1 = be16_to_cpu(id1);
	id2 = be16_to_cpu(id2);

	if (id1 == 0x0)
	dev_info(wm8350->dev, "Found Rev C device\n");
	else if (id1 == 0x6143) {
	switch ((id2 & WM8350_CHIP_REV_MASK) >> 12) {
	case WM8350_REV_E:
	dev_info(wm8350->dev, "Found Rev E device\n");
	wm8350->rev = WM8350_REV_E;
	break;
	case WM8350_REV_F:
	dev_info(wm8350->dev, "Found Rev F device\n");
	wm8350->rev = WM8350_REV_F;
	break;
	case WM8350_REV_G:
	dev_info(wm8350->dev, "Found Rev G device\n");
	wm8350->rev = WM8350_REV_G;
	break;
	default:
	/* For safety we refuse to run on unknown hardware */
	dev_info(wm8350->dev, "Found unknown rev\n");
	ret = -ENODEV;
	goto err;
	}
	} else {
	dev_info(wm8350->dev, "Device with ID %x is not a WM8350\n",
	id1);
	ret = -ENODEV;
	goto err;
	}

	mode = id2 & WM8350_CONF_STS_MASK >> 10;
	mask = id2 & WM8350_CUST_ID_MASK;
	dev_info(wm8350->dev, "Config mode %d, ROM mask %d\n", mode, mask);

	ret = wm8350_create_cache(wm8350, mode);
	if (ret < 0) {
	printk(KERN_ERR "wm8350: failed to create register cache\n");
	return ret;
	}

	if (pdata->init) {
	ret = pdata->init(wm8350);
	if (ret != 0) {
	dev_err(wm8350->dev, "Platform init() failed: %d\n",
	ret);
	goto err;
	}
	}

	return 0;

	err:
	kfree(wm8350->reg_cache);
	return ret;
	}
	EXPORT_SYMBOL_GPL(wm8350_device_init);

	void wm8350_device_exit(struct wm8350 *wm8350)
	{
	kfree(wm8350->reg_cache);
	}
	EXPORT_SYMBOL_GPL(wm8350_device_exit);

	MODULE_LICENSE("GPL");