[PATCH 0/4] regmap: Generic I2C and SPI register map library

[PATCH 0/4] regmap: Generic I2C and SPI register map library

[Mark Brown]

This is a version of a series I've been posting for most of this release
cycle which abstracts out a bunch of widely duplicated code for doing
register I/O on devices with control slow buses like I2C and SPI.  As
well as saving us code for the register I/O itself this should also make
it easier to factor out further higher level code for this class of
devices.

This version of the series includes a number of fairly small updates
from review by Grant and Jean and also a moderately invasive change to
have bus-specific registration functions at Grant's request.

I realise it's a bit late in the cycle but it'd be really good if we
could get this merged in the next merge window, or accepted for about
then so we can create a stable branch we can merge into subsystem trees
in order to get drivers using this merged for 3.2.  As there's only one
user included the series it should be pretty low risk.

The code is in a subdirectory because I'm anticipating it'll grow quite
a bit as we add facilities like fancy cache mechanisms on top of it.

A more verbose cover letter:

Many I2C and SPI based devices implement register maps on top of the raw
wire interface.  This is generally done in a very standard fashion by
devices, resulting in a lot of very similar code in drivers.  For some
time now ASoC has factored this code out into the subsystem but that's
only useful for audio devices.  The intention with this series is to
generalise the concept so that it can be used throughout the kernel.

It's not intended that this be suitable for all devices - some devices
have things that are hard to generalise like registers with variable
size and paging which are hard to support genericly.  At the minute the
code is focused on the common cases.  It is likely that the same code
could be used with other buses with similar properties to I2C and SPI.

Currently only physical I/O is handled, the intention is that once this
support has been reviewed and merged the generic register cache code
that ASoC includes will also be factored out too, along with logging and
diagnostic infrastructure for register maps.  For devices with read
heavy workloads (especially those that need a lot of read/modify/write
cycles) or which don't support read at all this can provide a useful
performance improvement and for sparse register maps there's a lot of
benefit in relatively complex cache code.
 
I'm not entirely happy with the implementation currently but am fairly
happy with the external interfaces.

A bunch more drivers have been converted to use this framework,
including the existing ASoC register I/O code, but due to various -next
dependencies these don't apply easily so I've omitted them from this
posting of the series - you can see them in the mailing list archives,
they've not been updated during the review.

There's a git branch at:

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git for-next

I've also created a regmap-asoc branch there which merges current ASoC
code with the regmap code.

The following changes since commit 620917de59eeb934b9f8cf35cc2d95c1ac8ed0fc:

  Linux 3.0-rc7 (2011-07-11 16:51:52 -0700)

are available in the git repository at:
  git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git for-next

Mark Brown (4):
      regmap: Add generic non-memory mapped register access API
      regmap: Add I2C bus support
      regmap: Add SPI bus support
      regulator: Convert tps65023 to use regmap API

 MAINTAINERS                            |    9 +
 drivers/base/Kconfig                   |    2 +
 drivers/base/Makefile                  |    1 +
 drivers/base/regmap/Kconfig            |    6 +
 drivers/base/regmap/Makefile           |    1 +
 drivers/base/regmap/regmap.c           |  455 ++++++++++++++++++++++++++++++++
 drivers/i2c/Kconfig                    |    4 +
 drivers/i2c/Makefile                   |    1 +
 drivers/i2c/i2c-regmap.c               |  115 ++++++++
 drivers/regulator/Kconfig              |    1 +
 drivers/regulator/tps65023-regulator.c |   97 ++-----
 drivers/spi/Kconfig                    |    4 +
 drivers/spi/Makefile                   |    1 +
 drivers/spi/spi-regmap.c               |   73 +++++
 include/linux/regmap.h                 |   79 ++++++
 15 files changed, 779 insertions(+), 70 deletions(-)
 create mode 100644 drivers/base/regmap/Kconfig
 create mode 100644 drivers/base/regmap/Makefile
 create mode 100644 drivers/base/regmap/regmap.c
 create mode 100644 drivers/i2c/i2c-regmap.c
 create mode 100644 drivers/spi/spi-regmap.c
 create mode 100644 include/linux/regmap.h

[PATCH 1/4] regmap: Add generic non-memory mapped register access API

[Mark Brown]

There are many places in the tree where we implement register access for
devices on non-memory mapped buses, especially I2C and SPI. Since hardware
designers seem to have settled on a relatively consistent set of register
interfaces this can be effectively factored out into shared code.  There
are a standard set of formats for marshalling data for exchange with the
device, with the actual I/O mechanisms generally being simple byte
streams.

We create an abstraction for marshaling data into formats which can be
sent on the control interfaces, and create a standard method for
plugging in actual transport underneath that.

This is mostly a refactoring and renaming of the bottom level of the
existing code for sharing register I/O which we have in ASoC. A
subsequent patch in this series converts ASoC to use this.  The main
difference in interface is that reads return values by writing to a
location provided by a pointer rather than in the return value, ensuring
we can use the full range of the type for register data.  We also use
unsigned types rather than ints for the same reason.

As some of the devices can have very large register maps the existing
ASoC code also contains infrastructure for managing register caches.
This cache work will be moved over in a future stage to allow for
separate review, the current patch only deals with the physical I/O.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
---
 MAINTAINERS                  |    7 +
 drivers/base/Kconfig         |    2 +
 drivers/base/Makefile        |    1 +
 drivers/base/regmap/Kconfig  |    6 +
 drivers/base/regmap/Makefile |    1 +
 drivers/base/regmap/regmap.c |  455 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/regmap.h       |   74 +++++++
 7 files changed, 546 insertions(+), 0 deletions(-)
 create mode 100644 drivers/base/regmap/Kconfig
 create mode 100644 drivers/base/regmap/Makefile
 create mode 100644 drivers/base/regmap/regmap.c
 create mode 100644 include/linux/regmap.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 187282d..b7eaf63 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 d57e8d0..b605d01 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 4c5701c..dd4f9b2 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 0000000..fc0eb1d
--- /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 0000000..7532e13
--- /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 0000000..cf3565c
--- /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 0000000..a26c1d0
--- /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
-- 
1.7.5.4

[PATCH 2/4] regmap: Add I2C bus support

[Mark Brown]

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
---
 MAINTAINERS              |    1 +
 drivers/i2c/Kconfig      |    4 ++
 drivers/i2c/Makefile     |    1 +
 drivers/i2c/i2c-regmap.c |  115 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/regmap.h   |    2 +
 5 files changed, 123 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/i2c-regmap.c

diff --git a/MAINTAINERS b/MAINTAINERS
index b7eaf63..21d7698 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5318,6 +5318,7 @@ 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:	drivers/i2c/i2c-regmap.c
 F:	include/linux/regmap.h
 
 RFKILL
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index 30f06e9..cba758b 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -6,6 +6,7 @@ menuconfig I2C
 	tristate "I2C support"
 	depends on HAS_IOMEM
 	select RT_MUTEXES
+	select I2C_REGMAP if REGMAP
 	---help---
 	  I2C (pronounce: I-square-C) is a slow serial bus protocol used in
 	  many micro controller applications and developed by Philips.  SMBus,
@@ -110,4 +111,7 @@ config I2C_DEBUG_BUS
 	  a problem with I2C support and want to see more of what is going
 	  on.
 
+config I2C_REGMAP
+	tristate
+
 endif # I2C
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index beee6b2..85d6699 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_I2C)		+= i2c-core.o
 obj-$(CONFIG_I2C_SMBUS)		+= i2c-smbus.o
 obj-$(CONFIG_I2C_CHARDEV)	+= i2c-dev.o
 obj-$(CONFIG_I2C_MUX)		+= i2c-mux.o
+obj-$(CONFIG_I2C_REGMAP)	+= i2c-regmap.o
 obj-y				+= algos/ busses/ muxes/
 
 ccflags-$(CONFIG_I2C_DEBUG_CORE) := -DDEBUG
diff --git a/drivers/i2c/i2c-regmap.c b/drivers/i2c/i2c-regmap.c
new file mode 100644
index 0000000..6237003
--- /dev/null
+++ b/drivers/i2c/i2c-regmap.c
@@ -0,0 +1,115 @@
+/*
+ * Register map access API - I2C support
+ *
+ * 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/regmap.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/init.h>
+
+static int regmap_i2c_write(struct device *dev, const void *data, size_t count)
+{
+	struct i2c_client *i2c = to_i2c_client(dev);
+	int ret;
+
+	ret = i2c_master_send(i2c, data, count);
+	if (ret == count)
+		return 0;
+	else if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int regmap_i2c_gather_write(struct device *dev,
+				   const void *reg, size_t reg_size,
+				   const void *val, size_t val_size)
+{
+	struct i2c_client *i2c = to_i2c_client(dev);
+	struct i2c_msg xfer[2];
+	int ret;
+
+	/* If the I2C controller can't do a gather tell the core, it
+	 * will substitute in a linear write for us.
+	 */
+	if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_PROTOCOL_MANGLING))
+		return -ENOTSUPP;
+
+	xfer[0].addr = i2c->addr;
+	xfer[0].flags = 0;
+	xfer[0].len = reg_size;
+	xfer[0].buf = (void *)reg;
+
+	xfer[1].addr = i2c->addr;
+	xfer[1].flags = I2C_M_NOSTART;
+	xfer[1].len = val_size;
+	xfer[1].buf = (void *)val;
+
+	ret = i2c_transfer(i2c->adapter, xfer, 2);
+	if (ret == 2)
+		return 0;
+	if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int regmap_i2c_read(struct device *dev,
+			   const void *reg, size_t reg_size,
+			   void *val, size_t val_size)
+{
+	struct i2c_client *i2c = to_i2c_client(dev);
+	struct i2c_msg xfer[2];
+	int ret;
+
+	xfer[0].addr = i2c->addr;
+	xfer[0].flags = 0;
+	xfer[0].len = reg_size;
+	xfer[0].buf = (void *)reg;
+
+	xfer[1].addr = i2c->addr;
+	xfer[1].flags = I2C_M_RD;
+	xfer[1].len = val_size;
+	xfer[1].buf = val;
+
+	ret = i2c_transfer(i2c->adapter, xfer, 2);
+	if (ret == 2)
+		return 0;
+	else if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static struct regmap_bus regmap_i2c = {
+	.type = &i2c_bus_type,
+	.write = regmap_i2c_write,
+	.gather_write = regmap_i2c_gather_write,
+	.read = regmap_i2c_read,
+	.owner = THIS_MODULE,
+};
+
+/**
+ * regmap_init_i2c(): Initialise register map
+ *
+ * @dev: Device that will be interacted with
+ * @config: Configuration for register map
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer to
+ * a struct regmap.
+ */
+struct regmap *regmap_init_i2c(struct device *dev,
+			       const struct regmap_config *config)
+{
+	return regmap_init(dev, &regmap_i2c, config);
+}
+EXPORT_SYMBOL_GPL(regmap_init_i2c);
+
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index a26c1d0..e509bac 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -59,6 +59,8 @@ struct regmap_bus {
 struct regmap *regmap_init(struct device *dev,
 			   const struct regmap_bus *bus,
 			   const struct regmap_config *config);
+struct regmap *regmap_init_i2c(struct device *dev,
+			       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,
-- 
1.7.5.4

[PATCH 3/4] regmap: Add SPI bus support

[Mark Brown]

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
---
 MAINTAINERS              |    1 +
 drivers/spi/Kconfig      |    4 ++
 drivers/spi/Makefile     |    1 +
 drivers/spi/spi-regmap.c |   73 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/regmap.h   |    3 ++
 5 files changed, 82 insertions(+), 0 deletions(-)
 create mode 100644 drivers/spi/spi-regmap.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 21d7698..dbe1d4f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5319,6 +5319,7 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git
 S:	Supported
 F:	drivers/base/regmap/
 F:	drivers/i2c/i2c-regmap.c
+F:	drivers/spi/spi-regmap.c
 F:	include/linux/regmap.h
 
 RFKILL
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index de35c3a..1c689a8 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -43,12 +43,16 @@ config SPI_MASTER
 #	boolean "SPI Master Support"
 	boolean
 	default SPI
+	select SPI_REGMAP if REGMAP
 	help
 	  If your system has an master-capable SPI controller (which
 	  provides the clock and chipselect), you can enable that
 	  controller and the protocol drivers for the SPI slave chips
 	  that are connected.
 
+config SPI_REGMAP
+	boolean
+
 if SPI_MASTER
 
 comment "SPI Master Controller Drivers"
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 0f8c69b..52dcf27 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -7,6 +7,7 @@ ccflags-$(CONFIG_SPI_DEBUG) := -DDEBUG
 # small core, mostly translating board-specific
 # config declarations into driver model code
 obj-$(CONFIG_SPI_MASTER)		+= spi.o
+obj-$(CONFIG_SPI_REGMAP)		+= spi-regmap.o
 
 # SPI master controller drivers (bus)
 obj-$(CONFIG_SPI_ALTERA)		+= spi_altera.o
diff --git a/drivers/spi/spi-regmap.c b/drivers/spi/spi-regmap.c
new file mode 100644
index 0000000..b994218
--- /dev/null
+++ b/drivers/spi/spi-regmap.c
@@ -0,0 +1,73 @@
+/*
+ * Register map access API - SPI support
+ *
+ * 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/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/init.h>
+
+static int regmap_spi_write(struct device *dev, const void *data, size_t count)
+{
+	struct spi_device *spi = to_spi_device(dev);
+
+	return spi_write(spi, data, count);
+}
+
+static int regmap_spi_gather_write(struct device *dev,
+				   const void *reg, size_t reg_len,
+				   const void *val, size_t val_len)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	struct spi_message m;
+	struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, },
+				     { .tx_buf = val, .len = val_len, }, };
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t[0], &m);
+	spi_message_add_tail(&t[1], &m);
+
+	return spi_sync(spi, &m);
+}
+
+static int regmap_spi_read(struct device *dev,
+			   const void *reg, size_t reg_size,
+			   void *val, size_t val_size)
+{
+	struct spi_device *spi = to_spi_device(dev);
+
+	return spi_write_then_read(spi, reg, reg_size, val, val_size);
+}
+
+static struct regmap_bus regmap_spi = {
+	.type = &spi_bus_type,
+	.write = regmap_spi_write,
+	.gather_write = regmap_spi_gather_write,
+	.read = regmap_spi_read,
+	.owner = THIS_MODULE,
+	.read_flag_mask = 0x80,
+};
+
+/**
+ * regmap_init_spi(): Initialise register map
+ *
+ * @dev: Device that will be interacted with
+ * @config: Configuration for register map
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer to
+ * a struct regmap.
+ */
+struct regmap *regmap_init_spi(struct device *dev,
+			       const struct regmap_config *config)
+{
+	return regmap_init(dev, &regmap_spi, config);
+}
+EXPORT_SYMBOL_GPL(regmap_init_spi);
+
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index e509bac..c549632 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -61,6 +61,9 @@ struct regmap *regmap_init(struct device *dev,
 			   const struct regmap_config *config);
 struct regmap *regmap_init_i2c(struct device *dev,
 			       const struct regmap_config *config);
+struct regmap *regmap_init_spi(struct device *dev,
+			       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,
-- 
1.7.5.4

[PATCH 4/4] regulator: Convert tps65023 to use regmap API

[Mark Brown]

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
---
 drivers/regulator/Kconfig              |    1 +
 drivers/regulator/tps65023-regulator.c |   97 +++++++++-----------------------
 2 files changed, 28 insertions(+), 70 deletions(-)

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index d7ed20f..c8dc5f0 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -235,6 +235,7 @@ config REGULATOR_TPS6105X
 config REGULATOR_TPS65023
 	tristate "TI TPS65023 Power regulators"
 	depends on I2C
+	select REGMAP
 	help
 	  This driver supports TPS65023 voltage regulator chips. TPS65023 provides
 	  three step-down converters and two general-purpose LDO voltage regulators.
diff --git a/drivers/regulator/tps65023-regulator.c b/drivers/regulator/tps65023-regulator.c
index fbddc15..bedb549 100644
--- a/drivers/regulator/tps65023-regulator.c
+++ b/drivers/regulator/tps65023-regulator.c
@@ -25,6 +25,7 @@
 #include <linux/i2c.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
+#include <linux/regmap.h>
 
 /* Register definitions */
 #define	TPS65023_REG_VERSION		0
@@ -125,93 +126,35 @@ struct tps_pmic {
 	struct i2c_client *client;
 	struct regulator_dev *rdev[TPS65023_NUM_REGULATOR];
 	const struct tps_info *info[TPS65023_NUM_REGULATOR];
-	struct mutex io_lock;
+	struct regmap *regmap;
 };
 
-static inline int tps_65023_read(struct tps_pmic *tps, u8 reg)
-{
-	return i2c_smbus_read_byte_data(tps->client, reg);
-}
-
-static inline int tps_65023_write(struct tps_pmic *tps, u8 reg, u8 val)
-{
-	return i2c_smbus_write_byte_data(tps->client, reg, val);
-}
-
 static int tps_65023_set_bits(struct tps_pmic *tps, u8 reg, u8 mask)
 {
-	int err, data;
-
-	mutex_lock(&tps->io_lock);
-
-	data = tps_65023_read(tps, reg);
-	if (data < 0) {
-		dev_err(&tps->client->dev, "Read from reg 0x%x failed\n", reg);
-		err = data;
-		goto out;
-	}
-
-	data |= mask;
-	err = tps_65023_write(tps, reg, data);
-	if (err)
-		dev_err(&tps->client->dev, "Write for reg 0x%x failed\n", reg);
-
-out:
-	mutex_unlock(&tps->io_lock);
-	return err;
+	return regmap_update_bits(tps->regmap, reg, mask, mask);
 }
 
 static int tps_65023_clear_bits(struct tps_pmic *tps, u8 reg, u8 mask)
 {
-	int err, data;
-
-	mutex_lock(&tps->io_lock);
-
-	data = tps_65023_read(tps, reg);
-	if (data < 0) {
-		dev_err(&tps->client->dev, "Read from reg 0x%x failed\n", reg);
-		err = data;
-		goto out;
-	}
-
-	data &= ~mask;
-
-	err = tps_65023_write(tps, reg, data);
-	if (err)
-		dev_err(&tps->client->dev, "Write for reg 0x%x failed\n", reg);
-
-out:
-	mutex_unlock(&tps->io_lock);
-	return err;
-
+	return regmap_update_bits(tps->regmap, reg, mask, 0);
 }
 
 static int tps_65023_reg_read(struct tps_pmic *tps, u8 reg)
 {
-	int data;
+	unsigned int val;
+	int ret;
 
-	mutex_lock(&tps->io_lock);
+	ret = regmap_read(tps->regmap, reg, &val);
 
-	data = tps_65023_read(tps, reg);
-	if (data < 0)
-		dev_err(&tps->client->dev, "Read from reg 0x%x failed\n", reg);
-
-	mutex_unlock(&tps->io_lock);
-	return data;
+	if (ret != 0)
+		return ret;
+	else
+		return val;
 }
 
 static int tps_65023_reg_write(struct tps_pmic *tps, u8 reg, u8 val)
 {
-	int err;
-
-	mutex_lock(&tps->io_lock);
-
-	err = tps_65023_write(tps, reg, val);
-	if (err < 0)
-		dev_err(&tps->client->dev, "Write for reg 0x%x failed\n", reg);
-
-	mutex_unlock(&tps->io_lock);
-	return err;
+	return regmap_write(tps->regmap, reg, val);
 }
 
 static int tps65023_dcdc_is_enabled(struct regulator_dev *dev)
@@ -463,6 +406,11 @@ static struct regulator_ops tps65023_ldo_ops = {
 	.list_voltage = tps65023_ldo_list_voltage,
 };
 
+static struct regmap_config tps65023_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
 static int __devinit tps_65023_probe(struct i2c_client *client,
 				     const struct i2c_device_id *id)
 {
@@ -488,7 +436,13 @@ static int __devinit tps_65023_probe(struct i2c_client *client,
 	if (!tps)
 		return -ENOMEM;
 
-	mutex_init(&tps->io_lock);
+	tps->regmap = regmap_init_i2c(&client->dev, &tps65023_regmap_config);
+	if (IS_ERR(tps->regmap)) {
+		error = PTR_ERR(tps->regmap);
+		dev_err(&client->dev, "Failed to allocate register map: %d\n",
+			error);
+		goto fail_alloc;
+	}
 
 	/* common for all regulators */
 	tps->client = client;
@@ -527,6 +481,8 @@ static int __devinit tps_65023_probe(struct i2c_client *client,
 	while (--i >= 0)
 		regulator_unregister(tps->rdev[i]);
 
+	regmap_exit(tps->regmap);
+ fail_alloc:
 	kfree(tps);
 	return error;
 }
@@ -545,6 +501,7 @@ static int __devexit tps_65023_remove(struct i2c_client *client)
 	for (i = 0; i < TPS65023_NUM_REGULATOR; i++)
 		regulator_unregister(tps->rdev[i]);
 
+	regmap_exit(tps->regmap);
 	kfree(tps);
 
 	return 0;
-- 
1.7.5.4

[PATCH 0/4] regmap: Generic I2C and SPI register map library

[Mark Brown]

This is a version of a series I've been posting for most of this release
cycle which abstracts out a bunch of widely duplicated code for doing
register I/O on devices with control slow buses like I2C and SPI.  As
well as saving us code for the register I/O itself this should also make
it easier to factor out further higher level code for this class of
devices.

The only update in this version is that I've moved the bus-specific code
back into the regmap directory.

I realise it's a bit late in the cycle but it'd be really good if we
could get this merged in the next merge window, or accepted for about
then so we can create a stable branch we can merge into subsystem trees
in order to get drivers using this merged for 3.2.  As there's only one
user included the series it should be pretty low risk.

The code is in a subdirectory because I'm anticipating it'll grow quite
a bit as we add facilities like fancy cache mechanisms on top of it.

A more verbose cover letter:

Many I2C and SPI based devices implement register maps on top of the raw
wire interface.  This is generally done in a very standard fashion by
devices, resulting in a lot of very similar code in drivers.  For some
time now ASoC has factored this code out into the subsystem but that's
only useful for audio devices.  The intention with this series is to
generalise the concept so that it can be used throughout the kernel.

It's not intended that this be suitable for all devices - some devices
have things that are hard to generalise like registers with variable
size and paging which are hard to support genericly.  At the minute the
code is focused on the common cases.  It is likely that the same code
could be used with other buses with similar properties to I2C and SPI.

Currently only physical I/O is handled, the intention is that once this
support has been reviewed and merged the generic register cache code
that ASoC includes will also be factored out too, along with logging and
diagnostic infrastructure for register maps.  For devices with read
heavy workloads (especially those that need a lot of read/modify/write
cycles) or which don't support read at all this can provide a useful
performance improvement and for sparse register maps there's a lot of
benefit in relatively complex cache code.
 
I'm not entirely happy with the implementation currently but am fairly
happy with the external interfaces.

A bunch more drivers have been converted to use this framework,
including the existing ASoC register I/O code, but due to various -next
dependencies these don't apply easily so I've omitted them from this
posting of the series - you can see them in the mailing list archives,
they've not been updated during the review.
 
There's a git branch at:

    git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git for-next

I've also created a regmap-asoc branch there which merges current ASoC
code with the regmap code.

The following changes since commit 620917de59eeb934b9f8cf35cc2d95c1ac8ed0fc:

  Linux 3.0-rc7 (2011-07-11 16:51:52 -0700)

are available in the git repository at:
  git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git for-next

Mark Brown (4):
      regmap: Add generic non-memory mapped register access API
      regmap: Add I2C bus support
      regmap: Add SPI bus support
      regulator: Convert tps65023 to use regmap API

 MAINTAINERS                            |    9 +
 drivers/base/Kconfig                   |    2 +
 drivers/base/Makefile                  |    1 +
 drivers/base/regmap/Kconfig            |   14 +
 drivers/base/regmap/Makefile           |    3 +
 drivers/base/regmap/regmap-i2c.c       |  115 ++++++++
 drivers/base/regmap/regmap-spi.c       |   73 +++++
 drivers/base/regmap/regmap.c           |  455 ++++++++++++++++++++++++++++++++
 drivers/regulator/Kconfig              |    1 +
 drivers/regulator/tps65023-regulator.c |   97 ++-----
 include/linux/regmap.h                 |   79 ++++++
 11 files changed, 779 insertions(+), 70 deletions(-)
 create mode 100644 drivers/base/regmap/Kconfig
 create mode 100644 drivers/base/regmap/Makefile
 create mode 100644 drivers/base/regmap/regmap-i2c.c
 create mode 100644 drivers/base/regmap/regmap-spi.c
 create mode 100644 drivers/base/regmap/regmap.c
 create mode 100644 include/linux/regmap.h

[PATCH 0/4] regmap: Generic I2C and SPI register map library

[Mark Brown]

This is a version of a series I've been posting for most of this release
cycle which abstracts out a bunch of widely duplicated code for doing
register I/O on devices with control slow buses like I2C and SPI.  As
well as saving us code for the register I/O itself this should also make
it easier to factor out further higher level code for this class of
devices.

The main change in this version of the series is that I've moved the
bus-specific files into the relevant drivers/ directories.  Hopefully
Jean, Ben and Grant will be OK with this and with some churn in this
code from the regmap tree that may be created as we build out the core
API and possibly refactor the interface to the bus code.

I realise it's a bit late in the cycle but it'd be really good if we
could get this merged in the next merge window, or accepted for about
then so we can create a stable branch we can merge into subsystem trees
in order to get drivers using this merged for 3.2.  As there's only one
user included the series it should be pretty low risk.

The code is in a subdirectory because I'm anticipating it'll grow quite
a bit as we add facilities like fancy cache mechanisms on top of it.

A more verbose cover letter:

Many I2C and SPI based devices implement register maps on top of the raw
wire interface.  This is generally done in a very standard fashion by
devices, resulting in a lot of very similar code in drivers.  For some
time now ASoC has factored this code out into the subsystem but that's
only useful for audio devices.  The intention with this series is to
generalise the concept so that it can be used throughout the kernel.

It's not intended that this be suitable for all devices - some devices
have things that are hard to generalise like registers with variable
size and paging which are hard to support genericly.  At the minute the
code is focused on the common cases.  It is likely that the same code
could be used with other buses with similar properties to I2C and SPI.

Currently only physical I/O is handled, the intention is that once this
support has been reviewed and merged the generic register cache code
that ASoC includes will also be factored out too, along with logging and
diagnostic infrastructure for register maps.  For devices with read
heavy workloads (especially those that need a lot of read/modify/write
cycles) or which don't support read at all this can provide a useful
performance improvement and for sparse register maps there's a lot of
benefit in relatively complex cache code.

I'm not entirely happy with the implementation currently but am fairly
happy with the external interfaces.

A bunch more drivers have been converted to use this framework,
including the existing ASoC register I/O code, but due to various -next
dependencies these don't apply easily so I've omitted them from this
posting of the series - you can see them in the mailing list archives,
they've not been updated during the review.

There's a git branch at:

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git for-next

I've also created a regmap-asoc branch there which merges current ASoC
code with the regmap code.

The following changes since commit 620917de59eeb934b9f8cf35cc2d95c1ac8ed0fc:

  Linux 3.0-rc7 (2011-07-11 16:51:52 -0700)

are available in the git repository at:
  git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git for-next

Mark Brown (4):
      regmap: Add generic non-memory mapped register access API
      regmap: Add I2C bus support
      regmap: Add SPI bus support
      regulator: Convert tps65023 to use regmap API

 MAINTAINERS                            |    7 +
 drivers/base/Kconfig                   |    2 +
 drivers/base/Makefile                  |    1 +
 drivers/base/regmap/Kconfig            |    6 +
 drivers/base/regmap/Makefile           |    1 +
 drivers/base/regmap/regmap.c           |  481 ++++++++++++++++++++++++++++++++
 drivers/i2c/Kconfig                    |    4 +
 drivers/i2c/Makefile                   |    1 +
 drivers/i2c/i2c-regmap.c               |  111 ++++++++
 drivers/regulator/Kconfig              |    1 +
 drivers/regulator/tps65023-regulator.c |   98 ++-----
 drivers/spi/Kconfig                    |    4 +
 drivers/spi/Makefile                   |    1 +
 drivers/spi/spi-regmap.c               |   76 +++++
 include/linux/regmap.h                 |   76 +++++
 15 files changed, 799 insertions(+), 71 deletions(-)
 create mode 100644 drivers/base/regmap/Kconfig
 create mode 100644 drivers/base/regmap/Makefile
 create mode 100644 drivers/base/regmap/regmap.c
 create mode 100644 drivers/i2c/i2c-regmap.c
 create mode 100644 drivers/spi/spi-regmap.c
 create mode 100644 include/linux/regmap.h

[PATCH 0/4] regmap: Generic I2C and SPI register map library

[Mark Brown]

This is a version of a series I've been posting for most of this release
cycle which abstracts out a bunch of widely duplicated code for doing
register I/O on devices with control slow buses like I2C and SPI.  As
well as saving us code for the register I/O itself this should also make
it easier to factor out further higher level code for this class of
devices.

Previously the patches had created a new directory under drivers/ but
one of the comments on the last review was that we should move to
drivers/base and another was that we should get this into mainline so
I've done that move and am now sending the patches to you.

The code is in a subdirectory because I'm anticipating it'll grow quite
a bit as we add facilities like fancy cache mechanisms on top of it.
The bus code isn't moved into the buses as I'm not currently entirely
happy with the internal interface to that and want to avoid cross tree
issues for the time being, I am pretty happy with the interfaces offered
to drivers though.

I realise it's a bit late in the cycle but it'd be really good if we
could get this merged in the next merge window, or accepted for about
then so we can create a stable branch we can merge into subsystem trees
in order to get drivers using this merged for 3.2.  As there's only one
user included the series it should be pretty low risk.

A more verbose cover letter:

Many I2C and SPI based devices implement register maps on top of the raw
wire interface.  This is generally done in a very standard fashion by
devices, resulting in a lot of very similar code in drivers.  For some
time now ASoC has factored this code out into the subsystem but that's
only useful for audio devices.  The intention with this series is to
generalise the concept so that it can be used throughout the kernel.

It's not intended that this be suitable for all devices - some devices
have things that are hard to generalise like registers with variable
size and paging which are hard to support genericly.  At the minute the
code is focused on the common cases.  It is likely that the same code
could be used with other buses with similar properties to I2C and SPI.

Currently only physical I/O is handled, the intention is that once this
support has been reviewed and merged the generic register cache code
that ASoC includes will also be factored out too.  For devices with read
heavy workloads (especially those that need a lot of read/modify/write
cycles) or which don't support read at all this can provide a useful
performance improvement and for sparse register maps there's a lot of
benefit in relatively complex cache code.

I'm not entirely happy with the implementation currently but am fairly
happy with the external interfaces.

A bunch more drivers have been converted to use this framework,
including the existing ASoC register I/O code, but due to various -next
dependencies these don't apply easily so I've omitted them from this
posting of the series.

There's a git branch at:

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git for-next

I've also created a regmap-asoc branch there which merges current ASoC
code with the regmap code.

The following changes since commit fe0d42203cb5616eeff68b14576a0f7e2dd56625:

  Linux 3.0-rc6 (2011-07-04 15:56:24 -0700)

are available in the git repository at:
  git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git for-next

Mark Brown (4):
      regmap: Add generic non-memory mapped register access API
      regmap: Add I2C bus support
      regmap: Add SPI bus support
      regulator: Convert tps65023 to use regmap API

 MAINTAINERS                            |    7 +
 drivers/base/Kconfig                   |    2 +
 drivers/base/Makefile                  |    1 +
 drivers/base/regmap/Kconfig            |    6 +
 drivers/base/regmap/Makefile           |    3 +
 drivers/base/regmap/regmap-i2c.c       |  113 ++++++++
 drivers/base/regmap/regmap-spi.c       |   75 +++++
 drivers/base/regmap/regmap.c           |  481 ++++++++++++++++++++++++++++++++
 drivers/regulator/Kconfig              |    1 +
 drivers/regulator/tps65023-regulator.c |   98 ++-----
 include/linux/regmap.h                 |   76 +++++
 11 files changed, 792 insertions(+), 71 deletions(-)
 create mode 100644 drivers/base/regmap/Kconfig
 create mode 100644 drivers/base/regmap/Makefile
 create mode 100644 drivers/base/regmap/regmap-i2c.c
 create mode 100644 drivers/base/regmap/regmap-spi.c
 create mode 100644 drivers/base/regmap/regmap.c
 create mode 100644 include/linux/regmap.h