[PATCH 5.10 69/73] regmap: Add bulk read/write callbacks into regmap_config

Sasha Levin
2024-03-13T16:48:00Z

From: Marek Vasut <marex@denx.de>

[ Upstream commit d77e745613680c54708470402e2b623dcd769681 ]

Currently the regmap_config structure only allows the user to implement
single element register read/write using .reg_read/.reg_write callbacks.
The regmap_bus already implements bulk counterparts of both, and is being
misused as a workaround for the missing bulk read/write callbacks in
regmap_config by a couple of drivers. To stop this misuse, add the bulk
read/write callbacks to regmap_config and call them from the regmap core
code.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
To: dri-devel@lists.freedesktop.org
Link: https://lore.kernel.org/r/20220430025145.640305-1-marex@denx.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Stable-dep-of: 3f42b142ea11 ("serial: max310x: fix IO data corruption in batched operations")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/base/regmap/internal.h | 4 ++
drivers/base/regmap/regmap.c | 76 ++++++++++++++++++----------------
include/linux/regmap.h | 12 ++++++
3 files changed, 56 insertions(+), 36 deletions(-)

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 0097696c31de2..2720d8d7bbfc9 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -104,6 +104,10 @@ struct regmap {
int (*reg_write)(void *context, unsigned int reg, unsigned int val);
int (*reg_update_bits)(void *context, unsigned int reg,
unsigned int mask, unsigned int val);
+ /* Bulk read/write */
+ int (*read)(void *context, const void *reg_buf, size_t reg_size,
+ void *val_buf, size_t val_size);
+ int (*write)(void *context, const void *data, size_t count);

bool defer_caching;

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 8f39aacdad0dc..2dfd6aa600450 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -800,12 +800,15 @@ struct regmap *__regmap_init(struct device *dev,
map->reg_stride_order = ilog2(map->reg_stride);
else
map->reg_stride_order = -1;
- map->use_single_read = config->use_single_read || !bus || !bus->read;
- map->use_single_write = config->use_single_write || !bus || !bus->write;
- map->can_multi_write = config->can_multi_write && bus && bus->write;
+ map->use_single_read = config->use_single_read || !(config->read || (bus && bus->read));
+ map->use_single_write = config->use_single_write || !(config->write || (bus && bus->write));
+ map->can_multi_write = config->can_multi_write && (config->write || (bus && bus->write));
if (bus) {
map->max_raw_read = bus->max_raw_read;
map->max_raw_write = bus->max_raw_write;
+ } else if (config->max_raw_read && config->max_raw_write) {
+ map->max_raw_read = config->max_raw_read;
+ map->max_raw_write = config->max_raw_write;
}
map->dev = dev;
map->bus = bus;
@@ -839,7 +842,16 @@ struct regmap *__regmap_init(struct device *dev,
map->read_flag_mask = bus->read_flag_mask;
}

- if (!bus) {
+ if (config && config->read && config->write) {
+ map->reg_read = _regmap_bus_read;
+
+ /* Bulk read/write */
+ map->read = config->read;
+ map->write = config->write;
+
+ reg_endian = REGMAP_ENDIAN_NATIVE;
+ val_endian = REGMAP_ENDIAN_NATIVE;
+ } else if (!bus) {
map->reg_read = config->reg_read;
map->reg_write = config->reg_write;
map->reg_update_bits = config->reg_update_bits;
@@ -856,10 +868,13 @@ struct regmap *__regmap_init(struct device *dev,
} else {
map->reg_read = _regmap_bus_read;
map->reg_update_bits = bus->reg_update_bits;
- }
+ /* Bulk read/write */
+ map->read = bus->read;
+ map->write = bus->write;

- reg_endian = regmap_get_reg_endian(bus, config);
- val_endian = regmap_get_val_endian(dev, bus, config);
+ reg_endian = regmap_get_reg_endian(bus, config);
+ val_endian = regmap_get_val_endian(dev, bus, config);
+ }

switch (config->reg_bits + map->reg_shift) {
case 2:
@@ -1628,8 +1643,6 @@ static int _regmap_raw_write_impl(struct regmap *map, unsigned int reg,
size_t len;
int i;

- WARN_ON(!map->bus);
-
/* Check for unwritable or noinc registers in range
* before we start
*/
@@ -1711,7 +1724,7 @@ static int _regmap_raw_write_impl(struct regmap *map, unsigned int reg,
val = work_val;
}

- if (map->async && map->bus->async_write) {
+ if (map->async && map->bus && map->bus->async_write) {
struct regmap_async *async;

trace_regmap_async_write_start(map, reg, val_len);
@@ -1779,10 +1792,10 @@ static int _regmap_raw_write_impl(struct regmap *map, unsigned int reg,
* write.
*/
if (val == work_val)
- ret = map->bus->write(map->bus_context, map->work_buf,
- map->format.reg_bytes +
- map->format.pad_bytes +
- val_len);
+ ret = map->write(map->bus_context, map->work_buf,
+ map->format.reg_bytes +
+ map->format.pad_bytes +
+ val_len);
else if (map->bus->gather_write)
ret = map->bus->gather_write(map->bus_context, map->work_buf,
map->format.reg_bytes +
@@ -1801,7 +1814,7 @@ static int _regmap_raw_write_impl(struct regmap *map, unsigned int reg,
memcpy(buf, map->work_buf, map->format.reg_bytes);
memcpy(buf + map->format.reg_bytes + map->format.pad_bytes,
val, val_len);
- ret = map->bus->write(map->bus_context, buf, len);
+ ret = map->write(map->bus_context, buf, len);

kfree(buf);
} else if (ret != 0 && !map->cache_bypass && map->format.parse_val) {
@@ -1858,7 +1871,7 @@ static int _regmap_bus_formatted_write(void *context, unsigned int reg,
struct regmap_range_node *range;
struct regmap *map = context;

- WARN_ON(!map->bus || !map->format.format_write);
+ WARN_ON(!map->format.format_write);

range = _regmap_range_lookup(map, reg);
if (range) {
@@ -1871,8 +1884,7 @@ static int _regmap_bus_formatted_write(void *context, unsigned int reg,

trace_regmap_hw_write_start(map, reg, 1);

- ret = map->bus->write(map->bus_context, map->work_buf,
- map->format.buf_size);
+ ret = map->write(map->bus_context, map->work_buf, map->format.buf_size);

trace_regmap_hw_write_done(map, reg, 1);

@@ -1892,7 +1904,7 @@ static int _regmap_bus_raw_write(void *context, unsigned int reg,
{
struct regmap *map = context;

- WARN_ON(!map->bus || !map->format.format_val);
+ WARN_ON(!map->format.format_val);

map->format.format_val(map->work_buf + map->format.reg_bytes
+ map->format.pad_bytes, val, 0);
@@ -1906,7 +1918,7 @@ static int _regmap_bus_raw_write(void *context, unsigned int reg,

static inline void *_regmap_map_get_context(struct regmap *map)
{
- return (map->bus) ? map : map->bus_context;
+ return (map->bus || (!map->bus && map->read)) ? map : map->bus_context;
}

int _regmap_write(struct regmap *map, unsigned int reg,
@@ -2313,7 +2325,7 @@ static int _regmap_raw_multi_reg_write(struct regmap *map,
u8 = buf;
*u8 |= map->write_flag_mask;

- ret = map->bus->write(map->bus_context, buf, len);
+ ret = map->write(map->bus_context, buf, len);

kfree(buf);

@@ -2619,9 +2631,7 @@ static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
struct regmap_range_node *range;
int ret;

- WARN_ON(!map->bus);
-
- if (!map->bus || !map->bus->read)
+ if (!map->read)
return -EINVAL;

range = _regmap_range_lookup(map, reg);
@@ -2637,9 +2647,9 @@ static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
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,
- map->format.reg_bytes + map->format.pad_bytes,
- val, val_len);
+ ret = map->read(map->bus_context, map->work_buf,
+ map->format.reg_bytes + map->format.pad_bytes,
+ val, val_len);

trace_regmap_hw_read_done(map, reg, val_len / map->format.val_bytes);

@@ -2750,8 +2760,6 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
unsigned int v;
int ret, i;

- if (!map->bus)
- return -EINVAL;
if (val_len % map->format.val_bytes)
return -EINVAL;
if (!IS_ALIGNED(reg, map->reg_stride))
@@ -2766,7 +2774,7 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
size_t chunk_count, chunk_bytes;
size_t chunk_regs = val_count;

- if (!map->bus->read) {
+ if (!map->read) {
ret = -ENOTSUPP;
goto out;
}
@@ -2826,7 +2834,7 @@ EXPORT_SYMBOL_GPL(regmap_raw_read);
* @val: Pointer to data buffer
* @val_len: Length of output buffer in bytes.
*
- * The regmap API usually assumes that bulk bus read operations will read a
+ * The regmap API usually assumes that bulk read operations will read a
* range of registers. Some devices have certain registers for which a read
* operation read will read from an internal FIFO.
*
@@ -2844,10 +2852,6 @@ int regmap_noinc_read(struct regmap *map, unsigned int reg,
size_t read_len;
int ret;

- if (!map->bus)
- return -EINVAL;
- if (!map->bus->read)
- return -ENOTSUPP;
if (val_len % map->format.val_bytes)
return -EINVAL;
if (!IS_ALIGNED(reg, map->reg_stride))
@@ -2961,7 +2965,7 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
if (val_count == 0)
return -EINVAL;

- if (map->bus && map->format.parse_inplace && (vol || map->cache_type == REGCACHE_NONE)) {
+ if (map->format.parse_inplace && (vol || map->cache_type == REGCACHE_NONE)) {
ret = regmap_raw_read(map, reg, val, val_bytes * val_count);
if (ret != 0)
return ret;
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index d6f0d876fa424..83a7485de78fb 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -294,6 +294,12 @@ typedef void (*regmap_unlock)(void *);
* if the function require special handling with lock and reg
* handling and the operation cannot be represented as a simple
* update_bits operation on a bus such as SPI, I2C, etc.
+ * @read: Optional callback that if filled will be used to perform all the
+ * bulk reads from the registers. Data is returned in the buffer used
+ * to transmit data.
+ * @write: Same as above for writing.
+ * @max_raw_read: Max raw read size that can be used on the device.
+ * @max_raw_write: Max raw write size that can be used on the device.
* @fast_io: Register IO is fast. Use a spinlock instead of a mutex
* to perform locking. This field is ignored if custom lock/unlock
* functions are used (see fields lock/unlock of struct regmap_config).
@@ -373,6 +379,12 @@ struct regmap_config {
int (*reg_write)(void *context, unsigned int reg, unsigned int val);
int (*reg_update_bits)(void *context, unsigned int reg,
unsigned int mask, unsigned int val);
+ /* Bulk read/write */
+ int (*read)(void *context, const void *reg_buf, size_t reg_size,
+ void *val_buf, size_t val_size);
+ int (*write)(void *context, const void *data, size_t count);
+ size_t max_raw_read;
+ size_t max_raw_write;

bool fast_io;

--
2.43.0