7 files changed, 546 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 187282da9213..b7eaf6393d36 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5313,6 +5313,13 @@ L:	reiserfs-devel@vger.kernel.org
 S:      Supported
 F:      fs/reiserfs/
 
+REGISTER MAP ABSTRACTION
+M:      Mark Brown <broonie@opensource.wolfsonmicro.com>
+T:      git git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git
+S:      Supported
+F:      drivers/base/regmap/
+F:      include/linux/regmap.h
+
 RFKILL
 M:      Johannes Berg <johannes@sipsolutions.net>
 L:      linux-wireless@vger.kernel.org
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index d57e8d0fb823..b605d01f5d45 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -168,4 +168,6 @@ config SYS_HYPERVISOR
         bool
         default n
 
+source "drivers/base/regmap/Kconfig"
+
 endmenu
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index 4c5701c15f53..dd4f9b245fc1 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -18,6 +18,7 @@ ifeq ($(CONFIG_SYSFS),y)
 obj-$(CONFIG_MODULES)   += module.o
 endif
 obj-$(CONFIG_SYS_HYPERVISOR) += hypervisor.o
+obj-$(CONFIG_REGMAP)    += regmap/
 
 ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
 
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);
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
new file mode 100644
index 000000000000..a26c1d001401
--- /dev/null
+++ b/include/linux/regmap.h
@@ -0,0 +1,74 @@
+#ifndef __LINUX_REGMAP_H
+#define __LINUX_REGMAP_H
+
+/*
+ * 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/device.h>
+#include <linux/list.h>
+#include <linux/module.h>
+
+struct regmap_config {
+        int reg_bits;
+        int val_bits;
+};
+
+typedef int (*regmap_hw_write)(struct device *dev, const void *data,
+                               size_t count);
+typedef int (*regmap_hw_gather_write)(struct device *dev,
+                                      const void *reg, size_t reg_len,
+                                      const void *val, size_t val_len);
+typedef int (*regmap_hw_read)(struct device *dev,
+                              const void *reg_buf, size_t reg_size,
+                              void *val_buf, size_t val_size);
+
+/**
+ * Description of a hardware bus for the register map infrastructure.
+ *
+ * @list: Internal use.
+ * @type: Bus type, used to identify bus to be used for a device.
+ * @write: Write operation.
+ * @gather_write: Write operation with split register/value, return -ENOTSUPP
+ *                if not implemented  on a given device.
+ * @read: Read operation.  Data is returned in the buffer used to transmit
+ *         data.
+ * @owner: Module with the bus implementation, used to pin the implementation
+ *         in memory.
+ * @read_flag_mask: Mask to be set in the top byte of the register when doing
+ *                  a read.
+ */
+struct regmap_bus {
+        struct list_head list;
+        struct bus_type *type;
+        regmap_hw_write write;
+        regmap_hw_gather_write gather_write;
+        regmap_hw_read read;
+        struct module *owner;
+        u8 read_flag_mask;
+};
+
+struct regmap *regmap_init(struct device *dev,
+                           const struct regmap_bus *bus,
+                           const struct regmap_config *config);
+void regmap_exit(struct regmap *map);
+int regmap_write(struct regmap *map, unsigned int reg, unsigned int val);
+int regmap_raw_write(struct regmap *map, unsigned int reg,
+                     const void *val, size_t val_len);
+int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val);
+int regmap_raw_read(struct regmap *map, unsigned int reg,
+                    void *val, size_t val_len);
+int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
+                     size_t val_count);
+int regmap_update_bits(struct regmap *map, unsigned int reg,
+                       unsigned int mask, unsigned int val);
+
+#endif