[PATCH v3 0/4] regmap: fixes

[PATCH v3 0/4] regmap: fixes

[Markus Pargmann]

Hi,

I changed the comments you mentioned in your review. I hope they are better
to understand now.

Best Regards,

Markus


Changes in v3:
- Change comments in patch 1 'regmap: Add missing comments about struct regmap_bus'
- Change description in patch 2 'regmap: Fix regmap_bulk_write for bus writes'

Changes in v2:
- Fixed free_context typo
- use_single_rw is now internally split into use_single_read/write
- Removed patches that wrongly tried to fix things
- Added simpler patches which check for the existence of bus->read/write to
  avoid null dereferences


Markus Pargmann (4):
  regmap: Add missing comments about struct regmap_bus
  regmap: Fix regmap_bulk_write for bus writes
  regmap: Split use_single_rw internally into use_single_read/write
  regmap: No multi_write support if bus->write does not exist

 drivers/base/regmap/internal.h   |  6 ++++--
 drivers/base/regmap/regcache.c   |  2 +-
 drivers/base/regmap/regmap-irq.c |  4 ++--
 drivers/base/regmap/regmap.c     | 30 ++++++++++++++++++++++++------
 include/linux/regmap.h           |  5 ++++-
 5 files changed, 35 insertions(+), 12 deletions(-)

-- 
2.4.6

[PATCH v3 1/4] regmap: Add missing comments about struct regmap_bus

[Markus Pargmann]

There are some fields of this struct undocumented or old. This patch
updates the missing comments.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
---
 include/linux/regmap.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 59c55ea0f0b5..73fc34d0c4c2 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -296,8 +296,12 @@ typedef void (*regmap_hw_free_context)(void *context);
  *                if not implemented  on a given device.
  * @async_write: Write operation which completes asynchronously, optional and
  *               must serialise with respect to non-async I/O.
+ * @reg_write: Write a single register value to the given register address. This
+ *             write operation has to complete when returning from the function.
  * @read: Read operation.  Data is returned in the buffer used to transmit
  *         data.
+ * @reg_read: Read a single register value from a given register address.
+ * @free_context: Free context.
  * @async_alloc: Allocate a regmap_async() structure.
  * @read_flag_mask: Mask to be set in the top byte of the register when doing
  *                  a read.
@@ -307,7 +311,6 @@ typedef void (*regmap_hw_free_context)(void *context);
  * @val_format_endian_default: Default endianness for formatted register
  *     values. Used when the regmap_config specifies DEFAULT. If this is
  *     DEFAULT, BIG is assumed.
- * @async_size: Size of struct used for async work.
  */
 struct regmap_bus {
 	bool fast_io;
-- 
2.4.6

[PATCH v3 2/4] regmap: Fix regmap_bulk_write for bus writes

[Markus Pargmann]

The regmap config does not prohibit val_bytes that are not powers of
two. But the current code of regmap_bulk_write for use_single_rw does
limit the possible val_bytes to 1, 2 and 4.

This patch fixes the behaviour to allow bus writes with non-standard
val_bytes sizes.

Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
---
 drivers/base/regmap/regmap.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 375fec92dc7e..e986e84b8871 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1678,9 +1678,15 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
 
 	/*
 	 * Some devices don't support bulk write, for
-	 * them we have a series of single write operations.
+	 * them we have a series of single write operations in the first two if
+	 * blocks.
+	 *
+	 * The first if block is used for memory mapped io. It does not allow
+	 * val_bytes of 3 for example.
+	 * The second one is used for busses which do not have this limitation
+	 * and can write arbitrary value lengths.
 	 */
-	if (!map->bus || map->use_single_rw) {
+	if (!map->bus) {
 		map->lock(map->lock_arg);
 		for (i = 0; i < val_count; i++) {
 			unsigned int ival;
@@ -1712,6 +1718,17 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
 		}
 out:
 		map->unlock(map->lock_arg);
+	} else if (map->use_single_rw) {
+		map->lock(map->lock_arg);
+		for (i = 0; i < val_count; i++) {
+			ret = _regmap_raw_write(map,
+						reg + (i * map->reg_stride),
+						val + (i * val_bytes),
+						val_bytes);
+			if (ret)
+				break;
+		}
+		map->unlock(map->lock_arg);
 	} else {
 		void *wval;
 
-- 
2.4.6

[PATCH v3 3/4] regmap: Split use_single_rw internally into use_single_read/write

[Markus Pargmann]

use_single_rw currently reflects the capabilities of the connected
device. The capabilities of the bus are currently missing for this
variable.

As there are read only and write only buses we need seperate values for
use_single_rw to also reflect tha capabilities of the bus.

This patch splits use_single_rw into use_single_read and
use_single_write. The initialization is changed to check the
configuration for use_single_rw and to check the capabilities of the
used bus.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
---
 drivers/base/regmap/internal.h   | 6 ++++--
 drivers/base/regmap/regcache.c   | 2 +-
 drivers/base/regmap/regmap-irq.c | 4 ++--
 drivers/base/regmap/regmap.c     | 9 +++++----
 4 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index b2b2849fc6d3..d744ae3926dd 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -139,8 +139,10 @@ struct regmap {
 	struct reg_default *patch;
 	int patch_regs;
 
-	/* if set, converts bulk rw to single rw */
-	bool use_single_rw;
+	/* if set, converts bulk read to single read */
+	bool use_single_read;
+	/* if set, converts bulk read to single read */
+	bool use_single_write;
 	/* if set, the device supports multi write mode */
 	bool can_multi_write;
 
diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index b9862d741a56..6f8a13ec32a4 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -729,7 +729,7 @@ int regcache_sync_block(struct regmap *map, void *block,
 			unsigned int block_base, unsigned int start,
 			unsigned int end)
 {
-	if (regmap_can_raw_write(map) && !map->use_single_rw)
+	if (regmap_can_raw_write(map) && !map->use_single_write)
 		return regcache_sync_block_raw(map, block, cache_present,
 					       block_base, start, end);
 	else
diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
index 2597600a5d26..38d1f72d869c 100644
--- a/drivers/base/regmap/regmap-irq.c
+++ b/drivers/base/regmap/regmap-irq.c
@@ -209,7 +209,7 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
 	 * Read in the statuses, using a single bulk read if possible
 	 * in order to reduce the I/O overheads.
 	 */
-	if (!map->use_single_rw && map->reg_stride == 1 &&
+	if (!map->use_single_read && map->reg_stride == 1 &&
 	    data->irq_reg_stride == 1) {
 		u8 *buf8 = data->status_reg_buf;
 		u16 *buf16 = data->status_reg_buf;
@@ -398,7 +398,7 @@ int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
 	else
 		d->irq_reg_stride = 1;
 
-	if (!map->use_single_rw && map->reg_stride == 1 &&
+	if (!map->use_single_read && map->reg_stride == 1 &&
 	    d->irq_reg_stride == 1) {
 		d->status_reg_buf = kmalloc(map->format.val_bytes *
 					    chip->num_regs, GFP_KERNEL);
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index e986e84b8871..75080774bf46 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -573,7 +573,8 @@ struct regmap *regmap_init(struct device *dev,
 		map->reg_stride = config->reg_stride;
 	else
 		map->reg_stride = 1;
-	map->use_single_rw = config->use_single_rw;
+	map->use_single_read = config->use_single_rw || !bus || !bus->read;
+	map->use_single_write = config->use_single_rw || !bus || !bus->write;
 	map->can_multi_write = config->can_multi_write;
 	map->dev = dev;
 	map->bus = bus;
@@ -763,7 +764,7 @@ struct regmap *regmap_init(struct device *dev,
 		if ((reg_endian != REGMAP_ENDIAN_BIG) ||
 		    (val_endian != REGMAP_ENDIAN_BIG))
 			goto err_map;
-		map->use_single_rw = true;
+		map->use_single_write = true;
 	}
 
 	if (!map->format.format_write &&
@@ -1718,7 +1719,7 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
 		}
 out:
 		map->unlock(map->lock_arg);
-	} else if (map->use_single_rw) {
+	} else if (map->use_single_write) {
 		map->lock(map->lock_arg);
 		for (i = 0; i < val_count; i++) {
 			ret = _regmap_raw_write(map,
@@ -2315,7 +2316,7 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
 		 * Some devices does not support bulk read, for
 		 * them we have a series of single read operations.
 		 */
-		if (map->use_single_rw) {
+		if (map->use_single_read) {
 			for (i = 0; i < val_count; i++) {
 				ret = regmap_raw_read(map,
 						reg + (i * map->reg_stride),
-- 
2.4.6

[PATCH v3 4/4] regmap: No multi_write support if bus->write does not exist

[Markus Pargmann]

There is no multi_write support available if we cannot use raw_write.
This is the case if bus->write is not implemented.

This patch adds a condition that we need bus and bus->write so that
can_multi_write is true.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
---
 drivers/base/regmap/regmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 75080774bf46..47fe0dfbbc46 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -575,7 +575,7 @@ struct regmap *regmap_init(struct device *dev,
 		map->reg_stride = 1;
 	map->use_single_read = config->use_single_rw || !bus || !bus->read;
 	map->use_single_write = config->use_single_rw || !bus || !bus->write;
-	map->can_multi_write = config->can_multi_write;
+	map->can_multi_write = config->can_multi_write && bus && bus->write;
 	map->dev = dev;
 	map->bus = bus;
 	map->bus_context = bus_context;
-- 
2.4.6