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regmap: Add bulk read/write callbacks into regmap_config
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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>
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Marek Vasut authored and Mark Brown committed May 5, 2022
1 parent 3123109 commit d77e745
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Showing 3 changed files with 56 additions and 36 deletions.
4 changes: 4 additions & 0 deletions drivers/base/regmap/internal.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -110,6 +110,10 @@ 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;

Expand Down
76 changes: 40 additions & 36 deletions drivers/base/regmap/regmap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -838,12 +838,15 @@ 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;
Expand Down Expand Up @@ -877,7 +880,16 @@ 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;
Expand All @@ -894,10 +906,13 @@ 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:
Expand Down Expand Up @@ -1671,8 +1686,6 @@ 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
*/
Expand Down Expand Up @@ -1754,7 +1767,7 @@ 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);
Expand Down Expand Up @@ -1822,10 +1835,10 @@ 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 +
Expand All @@ -1844,7 +1857,7 @@ 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) {
Expand Down Expand Up @@ -1901,7 +1914,7 @@ 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) {
Expand All @@ -1916,8 +1929,7 @@ 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);

Expand All @@ -1937,7 +1949,7 @@ 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);
Expand All @@ -1951,7 +1963,7 @@ 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,
Expand Down Expand Up @@ -2363,7 +2375,7 @@ 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);

Expand Down Expand Up @@ -2669,9 +2681,7 @@ 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);
Expand All @@ -2689,9 +2699,9 @@ 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);

Expand Down Expand Up @@ -2802,8 +2812,6 @@ 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))
Expand All @@ -2818,7 +2826,7 @@ 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;
}
Expand Down Expand Up @@ -2878,7 +2886,7 @@ 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.
*
Expand All @@ -2896,10 +2904,6 @@ 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))
Expand Down Expand Up @@ -3013,7 +3017,7 @@ 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;
Expand Down
12 changes: 12 additions & 0 deletions include/linux/regmap.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -299,6 +299,12 @@ 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).
Expand Down Expand Up @@ -385,6 +391,12 @@ 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;

Expand Down

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