[PATCH 0/2] Improve regmap support for more exotic devices

[PATCH 0/2] Improve regmap support for more exotic devices

[Tony Lindgren]

Hi,

Here are few patches that make it possible to use little endian
SPI devices with regmap-spi without custom read or write
functions.

Regards,

Tony

Tony Lindgren (2):
  regmap: Allow longer flag masks for read and write
  regma: Add missing little endian functions

 drivers/base/regmap/internal.h |  4 ++--
 drivers/base/regmap/regmap.c   | 41 ++++++++++++++++++++++++++++-------------
 include/linux/regmap.h         |  8 ++++----
 3 files changed, 34 insertions(+), 19 deletions(-)

-- 
2.9.3

[PATCH 1/2] regmap: Allow longer flag masks for read and write

[Tony Lindgren]

We currently only support masking the top bit for read and write
flags. Let's make the mask unsigned long and mask the bytes based
on the configured register length to make things more generic.

This allows using regmap for more exotic combinations like SPI
devices that need little endian addressing.

Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/base/regmap/internal.h |  4 ++--
 drivers/base/regmap/regmap.c   | 32 +++++++++++++++++++-------------
 include/linux/regmap.h         |  8 ++++----
 3 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -105,8 +105,8 @@ struct regmap {
 
 	bool defer_caching;
 
-	u8 read_flag_mask;
-	u8 write_flag_mask;
+	unsigned long read_flag_mask;
+	unsigned long write_flag_mask;
 
 	/* number of bits to (left) shift the reg value when formatting*/
 	int reg_shift;
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1319,12 +1319,26 @@ static int _regmap_select_page(struct regmap *map, unsigned int *reg,
 	return 0;
 }
 
+static void regmap_set_work_buf_flag_mask(struct regmap *map, int max_bytes,
+					  unsigned long mask)
+{
+	u8 *buf;
+	int i;
+
+	if (!mask || !map->work_buf)
+		return;
+
+	buf = map->work_buf;
+
+	for (i = 0; i < max_bytes; i++)
+		buf[i] |= (mask >> (8 * i)) & 0xff;
+}
+
 int _regmap_raw_write(struct regmap *map, unsigned int reg,
 		      const void *val, size_t val_len)
 {
 	struct regmap_range_node *range;
 	unsigned long flags;
-	u8 *u8 = map->work_buf;
 	void *work_val = map->work_buf + map->format.reg_bytes +
 		map->format.pad_bytes;
 	void *buf;
@@ -1393,8 +1407,8 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg,
 	}
 
 	map->format.format_reg(map->work_buf, reg, map->reg_shift);
-
-	u8[0] |= map->write_flag_mask;
+	regmap_set_work_buf_flag_mask(map, map->format.reg_bytes,
+				      map->write_flag_mask);
 
 	/*
 	 * Essentially all I/O mechanisms will be faster with a single
@@ -2270,7 +2284,6 @@ static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 			    unsigned int val_len)
 {
 	struct regmap_range_node *range;
-	u8 *u8 = map->work_buf;
 	int ret;
 
 	WARN_ON(!map->bus);
@@ -2287,15 +2300,8 @@ static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 	}
 
 	map->format.format_reg(map->work_buf, reg, map->reg_shift);
-
-	/*
-	 * Some buses or devices flag reads by setting the high bits in the
-	 * register address; 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.
-	 */
-	u8[0] |= map->read_flag_mask;
-
+	regmap_set_work_buf_flag_mask(map, map->format.reg_bytes,
+				      map->read_flag_mask);
 	trace_regmap_hw_read_start(map, reg, val_len / map->format.val_bytes);
 
 	ret = map->bus->read(map->bus_context, map->work_buf,
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -241,9 +241,9 @@ typedef void (*regmap_unlock)(void *);
  *                register cache support).
  * @num_reg_defaults: Number of elements in reg_defaults.
  *
- * @read_flag_mask: Mask to be set in the top byte of the register when doing
+ * @read_flag_mask: Mask to be set in the top bytes of the register when doing
  *                  a read.
- * @write_flag_mask: Mask to be set in the top byte of the register when doing
+ * @write_flag_mask: Mask to be set in the top bytes of the register when doing
  *                   a write. If both read_flag_mask and write_flag_mask are
  *                   empty the regmap_bus default masks are used.
  * @use_single_rw: If set, converts the bulk read and write operations into
@@ -299,8 +299,8 @@ struct regmap_config {
 	const void *reg_defaults_raw;
 	unsigned int num_reg_defaults_raw;
 
-	u8 read_flag_mask;
-	u8 write_flag_mask;
+	unsigned long read_flag_mask;
+	unsigned long write_flag_mask;
 
 	bool use_single_rw;
 	bool can_multi_write;
-- 
2.9.3

[PATCH 2/2] regma: Add missing little endian functions

[Tony Lindgren]

This with the longer read and write masks allow supporting more
exotic devices. For example a little endian SPI device:

static const struct regmap_config foo_regmap_config = {
	.reg_bits = 16,
	.reg_stride = 4,
	.val_bits = 16,
	.write_flag_mask = 0x8000,
	.reg_format_endian = REGMAP_ENDIAN_LITTLE,
	.val_format_endian = REGMAP_ENDIAN_LITTLE,
	...
};

Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/base/regmap/regmap.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -772,6 +772,9 @@ struct regmap *__regmap_init(struct device *dev,
 		case REGMAP_ENDIAN_BIG:
 			map->format.format_reg = regmap_format_16_be;
 			break;
+		case REGMAP_ENDIAN_LITTLE:
+			map->format.format_reg = regmap_format_16_le;
+			break;
 		case REGMAP_ENDIAN_NATIVE:
 			map->format.format_reg = regmap_format_16_native;
 			break;
@@ -791,6 +794,9 @@ struct regmap *__regmap_init(struct device *dev,
 		case REGMAP_ENDIAN_BIG:
 			map->format.format_reg = regmap_format_32_be;
 			break;
+		case REGMAP_ENDIAN_LITTLE:
+			map->format.format_reg = regmap_format_32_le;
+			break;
 		case REGMAP_ENDIAN_NATIVE:
 			map->format.format_reg = regmap_format_32_native;
 			break;
@@ -805,6 +811,9 @@ struct regmap *__regmap_init(struct device *dev,
 		case REGMAP_ENDIAN_BIG:
 			map->format.format_reg = regmap_format_64_be;
 			break;
+		case REGMAP_ENDIAN_LITTLE:
+			map->format.format_reg = regmap_format_64_le;
+			break;
 		case REGMAP_ENDIAN_NATIVE:
 			map->format.format_reg = regmap_format_64_native;
 			break;
-- 
2.9.3

Applied "regmap: Add missing little endian functions" to the regmap tree

[Mark Brown]

The patch

   regmap: Add missing little endian functions

has been applied to the regmap tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 55562449032c43b84f839e2fbb84bf1d351d6603 Mon Sep 17 00:00:00 2001
From: Tony Lindgren <tony@atomide.com>
Date: Thu, 15 Sep 2016 13:56:11 -0700
Subject: [PATCH] regmap: Add missing little endian functions

This with the longer read and write masks allow supporting more
exotic devices. For example a little endian SPI device:

static const struct regmap_config foo_regmap_config = {
	.reg_bits = 16,
	.reg_stride = 4,
	.val_bits = 16,
	.write_flag_mask = 0x8000,
	.reg_format_endian = REGMAP_ENDIAN_LITTLE,
	.val_format_endian = REGMAP_ENDIAN_LITTLE,
	...
};

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/base/regmap/regmap.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index a6a5236b6c8d..31cfe70e6d53 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -749,6 +749,9 @@ struct regmap *__regmap_init(struct device *dev,
 		case REGMAP_ENDIAN_BIG:
 			map->format.format_reg = regmap_format_16_be;
 			break;
+		case REGMAP_ENDIAN_LITTLE:
+			map->format.format_reg = regmap_format_16_le;
+			break;
 		case REGMAP_ENDIAN_NATIVE:
 			map->format.format_reg = regmap_format_16_native;
 			break;
@@ -768,6 +771,9 @@ struct regmap *__regmap_init(struct device *dev,
 		case REGMAP_ENDIAN_BIG:
 			map->format.format_reg = regmap_format_32_be;
 			break;
+		case REGMAP_ENDIAN_LITTLE:
+			map->format.format_reg = regmap_format_32_le;
+			break;
 		case REGMAP_ENDIAN_NATIVE:
 			map->format.format_reg = regmap_format_32_native;
 			break;
@@ -782,6 +788,9 @@ struct regmap *__regmap_init(struct device *dev,
 		case REGMAP_ENDIAN_BIG:
 			map->format.format_reg = regmap_format_64_be;
 			break;
+		case REGMAP_ENDIAN_LITTLE:
+			map->format.format_reg = regmap_format_64_le;
+			break;
 		case REGMAP_ENDIAN_NATIVE:
 			map->format.format_reg = regmap_format_64_native;
 			break;
-- 
2.8.1

Applied "regmap: Add missing little endian functions" to the regmap tree

[Mark Brown]

The patch

   regmap: Add missing little endian functions

has been applied to the regmap tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 55562449032c43b84f839e2fbb84bf1d351d6603 Mon Sep 17 00:00:00 2001
From: Tony Lindgren <tony@atomide.com>
Date: Thu, 15 Sep 2016 13:56:11 -0700
Subject: [PATCH] regmap: Add missing little endian functions

This with the longer read and write masks allow supporting more
exotic devices. For example a little endian SPI device:

static const struct regmap_config foo_regmap_config = {
	.reg_bits = 16,
	.reg_stride = 4,
	.val_bits = 16,
	.write_flag_mask = 0x8000,
	.reg_format_endian = REGMAP_ENDIAN_LITTLE,
	.val_format_endian = REGMAP_ENDIAN_LITTLE,
	...
};

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/base/regmap/regmap.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index a6a5236b6c8d..31cfe70e6d53 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -749,6 +749,9 @@ struct regmap *__regmap_init(struct device *dev,
 		case REGMAP_ENDIAN_BIG:
 			map->format.format_reg = regmap_format_16_be;
 			break;
+		case REGMAP_ENDIAN_LITTLE:
+			map->format.format_reg = regmap_format_16_le;
+			break;
 		case REGMAP_ENDIAN_NATIVE:
 			map->format.format_reg = regmap_format_16_native;
 			break;
@@ -768,6 +771,9 @@ struct regmap *__regmap_init(struct device *dev,
 		case REGMAP_ENDIAN_BIG:
 			map->format.format_reg = regmap_format_32_be;
 			break;
+		case REGMAP_ENDIAN_LITTLE:
+			map->format.format_reg = regmap_format_32_le;
+			break;
 		case REGMAP_ENDIAN_NATIVE:
 			map->format.format_reg = regmap_format_32_native;
 			break;
@@ -782,6 +788,9 @@ struct regmap *__regmap_init(struct device *dev,
 		case REGMAP_ENDIAN_BIG:
 			map->format.format_reg = regmap_format_64_be;
 			break;
+		case REGMAP_ENDIAN_LITTLE:
+			map->format.format_reg = regmap_format_64_le;
+			break;
 		case REGMAP_ENDIAN_NATIVE:
 			map->format.format_reg = regmap_format_64_native;
 			break;
-- 
2.8.1

Applied "regmap: Allow longer flag masks for read and write" to the regmap tree

[Mark Brown]

The patch

   regmap: Allow longer flag masks for read and write

has been applied to the regmap tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From f50e38c9966076465bc8d9dd0bc582c268a0031e Mon Sep 17 00:00:00 2001
From: Tony Lindgren <tony@atomide.com>
Date: Thu, 15 Sep 2016 13:56:10 -0700
Subject: [PATCH] regmap: Allow longer flag masks for read and write

We currently only support masking the top bit for read and write
flags. Let's make the mask unsigned long and mask the bytes based
on the configured register length to make things more generic.

This allows using regmap for more exotic combinations like SPI
devices that need little endian addressing.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/base/regmap/internal.h |  4 ++--
 drivers/base/regmap/regmap.c   | 32 +++++++++++++++++++-------------
 include/linux/regmap.h         |  8 ++++----
 3 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index a0380338946a..6636f03ac2da 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -105,8 +105,8 @@ struct regmap {
 
 	bool defer_caching;
 
-	u8 read_flag_mask;
-	u8 write_flag_mask;
+	unsigned long read_flag_mask;
+	unsigned long write_flag_mask;
 
 	/* number of bits to (left) shift the reg value when formatting*/
 	int reg_shift;
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 51fa7d66a393..a6a5236b6c8d 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1296,12 +1296,26 @@ static int _regmap_select_page(struct regmap *map, unsigned int *reg,
 	return 0;
 }
 
+static void regmap_set_work_buf_flag_mask(struct regmap *map, int max_bytes,
+					  unsigned long mask)
+{
+	u8 *buf;
+	int i;
+
+	if (!mask || !map->work_buf)
+		return;
+
+	buf = map->work_buf;
+
+	for (i = 0; i < max_bytes; i++)
+		buf[i] |= (mask >> (8 * i)) & 0xff;
+}
+
 int _regmap_raw_write(struct regmap *map, unsigned int reg,
 		      const void *val, size_t val_len)
 {
 	struct regmap_range_node *range;
 	unsigned long flags;
-	u8 *u8 = map->work_buf;
 	void *work_val = map->work_buf + map->format.reg_bytes +
 		map->format.pad_bytes;
 	void *buf;
@@ -1370,8 +1384,8 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg,
 	}
 
 	map->format.format_reg(map->work_buf, reg, map->reg_shift);
-
-	u8[0] |= map->write_flag_mask;
+	regmap_set_work_buf_flag_mask(map, map->format.reg_bytes,
+				      map->write_flag_mask);
 
 	/*
 	 * Essentially all I/O mechanisms will be faster with a single
@@ -2245,7 +2259,6 @@ static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 			    unsigned int val_len)
 {
 	struct regmap_range_node *range;
-	u8 *u8 = map->work_buf;
 	int ret;
 
 	WARN_ON(!map->bus);
@@ -2262,15 +2275,8 @@ static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 	}
 
 	map->format.format_reg(map->work_buf, reg, map->reg_shift);
-
-	/*
-	 * Some buses or devices flag reads by setting the high bits in the
-	 * register address; 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.
-	 */
-	u8[0] |= map->read_flag_mask;
-
+	regmap_set_work_buf_flag_mask(map, map->format.reg_bytes,
+				      map->read_flag_mask);
 	trace_regmap_hw_read_start(map, reg, val_len / map->format.val_bytes);
 
 	ret = map->bus->read(map->bus_context, map->work_buf,
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 2c12cc5af744..9adc7b21903d 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -241,9 +241,9 @@ typedef void (*regmap_unlock)(void *);
  *                register cache support).
  * @num_reg_defaults: Number of elements in reg_defaults.
  *
- * @read_flag_mask: Mask to be set in the top byte of the register when doing
+ * @read_flag_mask: Mask to be set in the top bytes of the register when doing
  *                  a read.
- * @write_flag_mask: Mask to be set in the top byte of the register when doing
+ * @write_flag_mask: Mask to be set in the top bytes of the register when doing
  *                   a write. If both read_flag_mask and write_flag_mask are
  *                   empty the regmap_bus default masks are used.
  * @use_single_rw: If set, converts the bulk read and write operations into
@@ -299,8 +299,8 @@ struct regmap_config {
 	const void *reg_defaults_raw;
 	unsigned int num_reg_defaults_raw;
 
-	u8 read_flag_mask;
-	u8 write_flag_mask;
+	unsigned long read_flag_mask;
+	unsigned long write_flag_mask;
 
 	bool use_single_rw;
 	bool can_multi_write;
-- 
2.8.1

Applied "regmap: Allow longer flag masks for read and write" to the regmap tree

[Mark Brown]

The patch

   regmap: Allow longer flag masks for read and write

has been applied to the regmap tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From f50e38c9966076465bc8d9dd0bc582c268a0031e Mon Sep 17 00:00:00 2001
From: Tony Lindgren <tony@atomide.com>
Date: Thu, 15 Sep 2016 13:56:10 -0700
Subject: [PATCH] regmap: Allow longer flag masks for read and write

We currently only support masking the top bit for read and write
flags. Let's make the mask unsigned long and mask the bytes based
on the configured register length to make things more generic.

This allows using regmap for more exotic combinations like SPI
devices that need little endian addressing.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/base/regmap/internal.h |  4 ++--
 drivers/base/regmap/regmap.c   | 32 +++++++++++++++++++-------------
 include/linux/regmap.h         |  8 ++++----
 3 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index a0380338946a..6636f03ac2da 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -105,8 +105,8 @@ struct regmap {
 
 	bool defer_caching;
 
-	u8 read_flag_mask;
-	u8 write_flag_mask;
+	unsigned long read_flag_mask;
+	unsigned long write_flag_mask;
 
 	/* number of bits to (left) shift the reg value when formatting*/
 	int reg_shift;
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 51fa7d66a393..a6a5236b6c8d 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1296,12 +1296,26 @@ static int _regmap_select_page(struct regmap *map, unsigned int *reg,
 	return 0;
 }
 
+static void regmap_set_work_buf_flag_mask(struct regmap *map, int max_bytes,
+					  unsigned long mask)
+{
+	u8 *buf;
+	int i;
+
+	if (!mask || !map->work_buf)
+		return;
+
+	buf = map->work_buf;
+
+	for (i = 0; i < max_bytes; i++)
+		buf[i] |= (mask >> (8 * i)) & 0xff;
+}
+
 int _regmap_raw_write(struct regmap *map, unsigned int reg,
 		      const void *val, size_t val_len)
 {
 	struct regmap_range_node *range;
 	unsigned long flags;
-	u8 *u8 = map->work_buf;
 	void *work_val = map->work_buf + map->format.reg_bytes +
 		map->format.pad_bytes;
 	void *buf;
@@ -1370,8 +1384,8 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg,
 	}
 
 	map->format.format_reg(map->work_buf, reg, map->reg_shift);
-
-	u8[0] |= map->write_flag_mask;
+	regmap_set_work_buf_flag_mask(map, map->format.reg_bytes,
+				      map->write_flag_mask);
 
 	/*
 	 * Essentially all I/O mechanisms will be faster with a single
@@ -2245,7 +2259,6 @@ static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 			    unsigned int val_len)
 {
 	struct regmap_range_node *range;
-	u8 *u8 = map->work_buf;
 	int ret;
 
 	WARN_ON(!map->bus);
@@ -2262,15 +2275,8 @@ static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 	}
 
 	map->format.format_reg(map->work_buf, reg, map->reg_shift);
-
-	/*
-	 * Some buses or devices flag reads by setting the high bits in the
-	 * register address; 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.
-	 */
-	u8[0] |= map->read_flag_mask;
-
+	regmap_set_work_buf_flag_mask(map, map->format.reg_bytes,
+				      map->read_flag_mask);
 	trace_regmap_hw_read_start(map, reg, val_len / map->format.val_bytes);
 
 	ret = map->bus->read(map->bus_context, map->work_buf,
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 2c12cc5af744..9adc7b21903d 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -241,9 +241,9 @@ typedef void (*regmap_unlock)(void *);
  *                register cache support).
  * @num_reg_defaults: Number of elements in reg_defaults.
  *
- * @read_flag_mask: Mask to be set in the top byte of the register when doing
+ * @read_flag_mask: Mask to be set in the top bytes of the register when doing
  *                  a read.
- * @write_flag_mask: Mask to be set in the top byte of the register when doing
+ * @write_flag_mask: Mask to be set in the top bytes of the register when doing
  *                   a write. If both read_flag_mask and write_flag_mask are
  *                   empty the regmap_bus default masks are used.
  * @use_single_rw: If set, converts the bulk read and write operations into
@@ -299,8 +299,8 @@ struct regmap_config {
 	const void *reg_defaults_raw;
 	unsigned int num_reg_defaults_raw;
 
-	u8 read_flag_mask;
-	u8 write_flag_mask;
+	unsigned long read_flag_mask;
+	unsigned long write_flag_mask;
 
 	bool use_single_rw;
 	bool can_multi_write;
-- 
2.8.1