3 files changed, 462 insertions, 0 deletions
diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig
new file mode 100644
index 000000000000..fc0eb1d484dd
--- /dev/null
+++ b/drivers/base/regmap/Kconfig
@@ -0,0 +1,6 @@
+# Generic register map support.  There are no user servicable options here,
+# this is an API intended to be used by other kernel subsystems.  These
+# subsystems should select the appropriate symbols.
+
+config REGMAP
+	bool
diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile
new file mode 100644
index 000000000000..7532e13e0f00
--- /dev/null
+++ b/drivers/base/regmap/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_REGMAP) += regmap.o
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
new file mode 100644
index 000000000000..cf3565cae93d
--- /dev/null
+++ b/drivers/base/regmap/regmap.c
@@ -0,0 +1,455 @@
+/*
+ * Register map access API
+ *
+ * Copyright 2011 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 version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+
+#include <linux/regmap.h>
+
+struct regmap;
+
+struct regmap_format {
+	size_t buf_size;
+	size_t reg_bytes;
+	size_t val_bytes;
+	void (*format_write)(struct regmap *map,
+			     unsigned int reg, unsigned int val);
+	void (*format_reg)(void *buf, unsigned int reg);
+	void (*format_val)(void *buf, unsigned int val);
+	unsigned int (*parse_val)(void *buf);
+};
+
+struct regmap {
+	struct mutex lock;
+
+	struct device *dev; /* Device we do I/O on */
+	void *work_buf;     /* Scratch buffer used to format I/O */
+	struct regmap_format format;  /* Buffer format */
+	const struct regmap_bus *bus;
+};
+
+static void regmap_format_4_12_write(struct regmap *map,
+				     unsigned int reg, unsigned int val)
+{
+	__be16 *out = map->work_buf;
+	*out = cpu_to_be16((reg << 12) | val);
+}
+
+static void regmap_format_7_9_write(struct regmap *map,
+				    unsigned int reg, unsigned int val)
+{
+	__be16 *out = map->work_buf;
+	*out = cpu_to_be16((reg << 9) | val);
+}
+
+static void regmap_format_8(void *buf, unsigned int val)
+{
+	u8 *b = buf;
+
+	b[0] = val;
+}
+
+static void regmap_format_16(void *buf, unsigned int val)
+{
+	__be16 *b = buf;
+
+	b[0] = cpu_to_be16(val);
+}
+
+static unsigned int regmap_parse_8(void *buf)
+{
+	u8 *b = buf;
+
+	return b[0];
+}
+
+static unsigned int regmap_parse_16(void *buf)
+{
+	__be16 *b = buf;
+
+	b[0] = be16_to_cpu(b[0]);
+
+	return b[0];
+}
+
+/**
+ * regmap_init(): Initialise register map
+ *
+ * @dev: Device that will be interacted with
+ * @bus: Bus-specific callbacks to use with device
+ * @config: Configuration for register map
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer to
+ * a struct regmap.  This function should generally not be called
+ * directly, it should be called by bus-specific init functions.
+ */
+struct regmap *regmap_init(struct device *dev,
+			   const struct regmap_bus *bus,
+			   const struct regmap_config *config)
+{
+	struct regmap *map;
+	int ret = -EINVAL;
+
+	if (!bus || !config)
+		return NULL;
+
+	map = kzalloc(sizeof(*map), GFP_KERNEL);
+	if (map == NULL) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	mutex_init(&map->lock);
+	map->format.buf_size = (config->reg_bits + config->val_bits) / 8;
+	map->format.reg_bytes = config->reg_bits / 8;
+	map->format.val_bytes = config->val_bits / 8;
+	map->dev = dev;
+	map->bus = bus;
+
+	switch (config->reg_bits) {
+	case 4:
+		switch (config->val_bits) {
+		case 12:
+			map->format.format_write = regmap_format_4_12_write;
+			break;
+		default:
+			goto err_map;
+		}
+		break;
+
+	case 7:
+		switch (config->val_bits) {
+		case 9:
+			map->format.format_write = regmap_format_7_9_write;
+			break;
+		default:
+			goto err_map;
+		}
+		break;
+
+	case 8:
+		map->format.format_reg = regmap_format_8;
+		break;
+
+	case 16:
+		map->format.format_reg = regmap_format_16;
+		break;
+
+	default:
+		goto err_map;
+	}
+
+	switch (config->val_bits) {
+	case 8:
+		map->format.format_val = regmap_format_8;
+		map->format.parse_val = regmap_parse_8;
+		break;
+	case 16:
+		map->format.format_val = regmap_format_16;
+		map->format.parse_val = regmap_parse_16;
+		break;
+	}
+
+	if (!map->format.format_write &&
+	    !(map->format.format_reg && map->format.format_val))
+		goto err_map;
+
+	map->work_buf = kmalloc(map->format.buf_size, GFP_KERNEL);
+	if (map->work_buf == NULL) {
+		ret = -ENOMEM;
+		goto err_bus;
+	}
+
+	return map;
+
+err_bus:
+	module_put(map->bus->owner);
+err_map:
+	kfree(map);
+err:
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(regmap_init);
+
+/**
+ * regmap_exit(): Free a previously allocated register map
+ */
+void regmap_exit(struct regmap *map)
+{
+	kfree(map->work_buf);
+	module_put(map->bus->owner);
+	kfree(map);
+}
+EXPORT_SYMBOL_GPL(regmap_exit);
+
+static int _regmap_raw_write(struct regmap *map, unsigned int reg,
+			     const void *val, size_t val_len)
+{
+	void *buf;
+	int ret = -ENOTSUPP;
+	size_t len;
+
+	map->format.format_reg(map->work_buf, reg);
+
+	/* Try to do a gather write if we can */
+	if (map->bus->gather_write)
+		ret = map->bus->gather_write(map->dev, map->work_buf,
+					     map->format.reg_bytes,
+					     val, val_len);
+
+	/* Otherwise fall back on linearising by hand. */
+	if (ret == -ENOTSUPP) {
+		len = map->format.reg_bytes + val_len;
+		buf = kmalloc(len, GFP_KERNEL);
+		if (!buf)
+			return -ENOMEM;
+
+		memcpy(buf, map->work_buf, map->format.reg_bytes);
+		memcpy(buf + map->format.reg_bytes, val, val_len);
+		ret = map->bus->write(map->dev, buf, len);
+
+		kfree(buf);
+	}
+
+	return ret;
+}
+
+static int _regmap_write(struct regmap *map, unsigned int reg,
+			 unsigned int val)
+{
+	BUG_ON(!map->format.format_write && !map->format.format_val);
+
+	if (map->format.format_write) {
+		map->format.format_write(map, reg, val);
+
+		return map->bus->write(map->dev, map->work_buf,
+				       map->format.buf_size);
+	} else {
+		map->format.format_val(map->work_buf + map->format.reg_bytes,
+				       val);
+		return _regmap_raw_write(map, reg,
+					 map->work_buf + map->format.reg_bytes,
+					 map->format.val_bytes);
+	}
+}
+
+/**
+ * regmap_write(): Write a value to a single register
+ *
+ * @map: Register map to write to
+ * @reg: Register to write to
+ * @val: Value to be written
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_write(struct regmap *map, unsigned int reg, unsigned int val)
+{
+	int ret;
+
+	mutex_lock(&map->lock);
+
+	ret = _regmap_write(map, reg, val);
+
+	mutex_unlock(&map->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_write);
+
+/**
+ * regmap_raw_write(): Write raw values to one or more registers
+ *
+ * @map: Register map to write to
+ * @reg: Initial register to write to
+ * @val: Block of data to be written, laid out for direct transmission to the
+ *       device
+ * @val_len: Length of data pointed to by val.
+ *
+ * This function is intended to be used for things like firmware
+ * download where a large block of data needs to be transferred to the
+ * device.  No formatting will be done on the data provided.
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_raw_write(struct regmap *map, unsigned int reg,
+		     const void *val, size_t val_len)
+{
+	int ret;
+
+	mutex_lock(&map->lock);
+
+	ret = _regmap_raw_write(map, reg, val, val_len);
+
+	mutex_unlock(&map->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_raw_write);
+
+static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
+			    unsigned int val_len)
+{
+	u8 *u8 = map->work_buf;
+	int ret;
+
+	map->format.format_reg(map->work_buf, reg);
+
+	/*
+	 * Some buses flag reads by setting the high bits in the
+	 * register addresss; since it's always the high bits for all
+	 * current formats we can do this here rather than in
+	 * formatting.  This may break if we get interesting formats.
+	 */
+	if (map->bus->read_flag_mask)
+		u8[0] |= map->bus->read_flag_mask;
+
+	ret = map->bus->read(map->dev, map->work_buf, map->format.reg_bytes,
+			     val, map->format.val_bytes);
+	if (ret != 0)
+		return ret;
+
+	return 0;
+}
+
+static int _regmap_read(struct regmap *map, unsigned int reg,
+			unsigned int *val)
+{
+	int ret;
+
+	if (!map->format.parse_val)
+		return -EINVAL;
+
+	ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes);
+	if (ret == 0)
+		*val = map->format.parse_val(map->work_buf);
+
+	return ret;
+}
+
+/**
+ * regmap_read(): Read a value from a single register
+ *
+ * @map: Register map to write to
+ * @reg: Register to be read from
+ * @val: Pointer to store read value
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val)
+{
+	int ret;
+
+	mutex_lock(&map->lock);
+
+	ret = _regmap_read(map, reg, val);
+
+	mutex_unlock(&map->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_read);
+
+/**
+ * regmap_raw_read(): Read raw data from the device
+ *
+ * @map: Register map to write to
+ * @reg: First register to be read from
+ * @val: Pointer to store read value
+ * @val_len: Size of data to read
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
+		    size_t val_len)
+{
+	int ret;
+
+	mutex_lock(&map->lock);
+
+	ret = _regmap_raw_read(map, reg, val, val_len);
+
+	mutex_unlock(&map->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_raw_read);
+
+/**
+ * regmap_bulk_read(): Read multiple registers from the device
+ *
+ * @map: Register map to write to
+ * @reg: First register to be read from
+ * @val: Pointer to store read value, in native register size for device
+ * @val_count: Number of registers to read
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
+		     size_t val_count)
+{
+	int ret, i;
+	size_t val_bytes = map->format.val_bytes;
+
+	if (!map->format.parse_val)
+		return -EINVAL;
+
+	ret = regmap_raw_read(map, reg, val, val_bytes * val_count);
+	if (ret != 0)
+		return ret;
+
+	for (i = 0; i < val_count * val_bytes; i += val_bytes)
+		map->format.parse_val(val + i);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(regmap_bulk_read);
+
+/**
+ * remap_update_bits: Perform a read/modify/write cycle on the register map
+ *
+ * @map: Register map to update
+ * @reg: Register to update
+ * @mask: Bitmask to change
+ * @val: New value for bitmask
+ *
+ * Returns zero for success, a negative number on error.
+ */
+int regmap_update_bits(struct regmap *map, unsigned int reg,
+		       unsigned int mask, unsigned int val)
+{
+	int ret;
+	unsigned int tmp;
+
+	mutex_lock(&map->lock);
+
+	ret = _regmap_read(map, reg, &tmp);
+	if (ret != 0)
+		goto out;
+
+	tmp &= ~mask;
+	tmp |= val & mask;
+
+	ret = _regmap_write(map, reg, tmp);
+
+out:
+	mutex_unlock(&map->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_update_bits);