[PATCH v3 lora-next 1/5] regmap: Add regmap_noinc_write API

From: Ben Whitten
Date: Fri Oct 12 2018 - 12:26:44 EST


The regmap API had a noinc_read function added for instances where devices
supported returning data from an internal FIFO in a single read.

This commit adds the noinc_write variant to allow writing to a non
incrementing register, this is used in devices such as the sx1301 for
loading firmware.

Signed-off-by: Ben Whitten <ben.whitten@xxxxxxxxxxxxx>
---
drivers/base/regmap/internal.h | 3 ++
drivers/base/regmap/regmap.c | 77 ++++++++++++++++++++++++++++++++++++++++++
include/linux/regmap.h | 19 +++++++++++
3 files changed, 99 insertions(+)

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index a6bf34d63..404f123 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -94,11 +94,13 @@ struct regmap {
bool (*readable_reg)(struct device *dev, unsigned int reg);
bool (*volatile_reg)(struct device *dev, unsigned int reg);
bool (*precious_reg)(struct device *dev, unsigned int reg);
+ bool (*writeable_noinc_reg)(struct device *dev, unsigned int reg);
bool (*readable_noinc_reg)(struct device *dev, unsigned int reg);
const struct regmap_access_table *wr_table;
const struct regmap_access_table *rd_table;
const struct regmap_access_table *volatile_table;
const struct regmap_access_table *precious_table;
+ const struct regmap_access_table *wr_noinc_table;
const struct regmap_access_table *rd_noinc_table;

int (*reg_read)(void *context, unsigned int reg, unsigned int *val);
@@ -183,6 +185,7 @@ bool regmap_writeable(struct regmap *map, unsigned int reg);
bool regmap_readable(struct regmap *map, unsigned int reg);
bool regmap_volatile(struct regmap *map, unsigned int reg);
bool regmap_precious(struct regmap *map, unsigned int reg);
+bool regmap_writeable_noinc(struct regmap *map, unsigned int reg);
bool regmap_readable_noinc(struct regmap *map, unsigned int reg);

int _regmap_write(struct regmap *map, unsigned int reg,
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 0360a90..d4f1fc6 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -168,6 +168,17 @@ bool regmap_precious(struct regmap *map, unsigned int reg)
return false;
}

+bool regmap_writeable_noinc(struct regmap *map, unsigned int reg)
+{
+ if (map->writeable_noinc_reg)
+ return map->writeable_noinc_reg(map->dev, reg);
+
+ if (map->wr_noinc_table)
+ return regmap_check_range_table(map, reg, map->wr_noinc_table);
+
+ return true;
+}
+
bool regmap_readable_noinc(struct regmap *map, unsigned int reg)
{
if (map->readable_noinc_reg)
@@ -777,11 +788,13 @@ struct regmap *__regmap_init(struct device *dev,
map->rd_table = config->rd_table;
map->volatile_table = config->volatile_table;
map->precious_table = config->precious_table;
+ map->wr_noinc_table = config->wr_noinc_table;
map->rd_noinc_table = config->rd_noinc_table;
map->writeable_reg = config->writeable_reg;
map->readable_reg = config->readable_reg;
map->volatile_reg = config->volatile_reg;
map->precious_reg = config->precious_reg;
+ map->writeable_noinc_reg = config->writeable_noinc_reg;
map->readable_noinc_reg = config->readable_noinc_reg;
map->cache_type = config->cache_type;

@@ -1298,6 +1311,7 @@ int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config)
map->readable_reg = config->readable_reg;
map->volatile_reg = config->volatile_reg;
map->precious_reg = config->precious_reg;
+ map->writeable_noinc_reg = config->writeable_noinc_reg;
map->readable_noinc_reg = config->readable_noinc_reg;
map->cache_type = config->cache_type;

@@ -1898,6 +1912,69 @@ int regmap_raw_write(struct regmap *map, unsigned int reg,
EXPORT_SYMBOL_GPL(regmap_raw_write);

/**
+ * regmap_noinc_write(): Write data from a register without incrementing the
+ * register number
+ *
+ * @map: Register map to write to
+ * @reg: Register to write to
+ * @val: Pointer to data buffer
+ * @val_len: Length of output buffer in bytes.
+ *
+ * The regmap API usually assumes that bulk bus write operations will write a
+ * range of registers. Some devices have certain registers for which a write
+ * operation can write to an internal FIFO.
+ *
+ * The target register must be volatile but registers after it can be
+ * completely unrelated cacheable registers.
+ *
+ * This will attempt multiple writes as required to write val_len bytes.
+ *
+ * A value of zero will be returned on success, a negative errno will be
+ * returned in error cases.
+ */
+int regmap_noinc_write(struct regmap *map, unsigned int reg,
+ const void *val, size_t val_len)
+{
+ size_t write_len;
+ int ret;
+
+ if (!map->bus)
+ return -EINVAL;
+ if (!map->bus->write)
+ return -ENOTSUPP;
+ if (val_len % map->format.val_bytes)
+ return -EINVAL;
+ if (!IS_ALIGNED(reg, map->reg_stride))
+ return -EINVAL;
+ if (val_len == 0)
+ return -EINVAL;
+
+ map->lock(map->lock_arg);
+
+ if (!regmap_volatile(map, reg) || !regmap_writeable_noinc(map, reg)) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ while (val_len) {
+ if (map->max_raw_write && map->max_raw_write < val_len)
+ write_len = map->max_raw_write;
+ else
+ write_len = val_len;
+ ret = _regmap_raw_write(map, reg, val, write_len);
+ if (ret)
+ goto out_unlock;
+ val = ((u8 *)val) + write_len;
+ val_len -= write_len;
+ }
+
+out_unlock:
+ map->unlock(map->lock_arg);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_noinc_write);
+
+/**
* regmap_field_update_bits_base() - Perform a read/modify/write cycle a
* register field.
*
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 379505a..de04dc4 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -268,6 +268,13 @@ typedef void (*regmap_unlock)(void *);
* field is NULL but precious_table (see below) is not, the
* check is performed on such table (a register is precious if
* it belongs to one of the ranges specified by precious_table).
+ * @writeable_noinc_reg: Optional callback returning true if the register
+ * supports multiple write operations without incrementing
+ * the register number. If this field is NULL but
+ * wr_noinc_table (see below) is not, the check is
+ * performed on such table (a register is no increment
+ * writeable if it belongs to one of the ranges specified
+ * by wr_noinc_table).
* @readable_noinc_reg: Optional callback returning true if the register
* supports multiple read operations without incrementing
* the register number. If this field is NULL but
@@ -302,6 +309,7 @@ typedef void (*regmap_unlock)(void *);
* @rd_table: As above, for read access.
* @volatile_table: As above, for volatile registers.
* @precious_table: As above, for precious registers.
+ * @wr_noinc_table: As above, for no increment writeable registers.
* @rd_noinc_table: As above, for no increment readable registers.
* @reg_defaults: Power on reset values for registers (for use with
* register cache support).
@@ -352,6 +360,7 @@ struct regmap_config {
bool (*readable_reg)(struct device *dev, unsigned int reg);
bool (*volatile_reg)(struct device *dev, unsigned int reg);
bool (*precious_reg)(struct device *dev, unsigned int reg);
+ bool (*writeable_noinc_reg)(struct device *dev, unsigned int reg);
bool (*readable_noinc_reg)(struct device *dev, unsigned int reg);

bool disable_locking;
@@ -369,6 +378,7 @@ struct regmap_config {
const struct regmap_access_table *rd_table;
const struct regmap_access_table *volatile_table;
const struct regmap_access_table *precious_table;
+ const struct regmap_access_table *wr_noinc_table;
const struct regmap_access_table *rd_noinc_table;
const struct reg_default *reg_defaults;
unsigned int num_reg_defaults;
@@ -979,6 +989,8 @@ int regmap_write(struct regmap *map, unsigned int reg, unsigned int val);
int regmap_write_async(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_noinc_write(struct regmap *map, unsigned int reg,
+ const void *val, size_t val_len);
int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
size_t val_count);
int regmap_multi_reg_write(struct regmap *map, const struct reg_sequence *regs,
@@ -1222,6 +1234,13 @@ static inline int regmap_raw_write_async(struct regmap *map, unsigned int reg,
return -EINVAL;
}

+static inline int regmap_noinc_write(struct regmap *map, unsigned int reg,
+ const void *val, size_t val_len)
+{
+ WARN_ONCE(1, "regmap API is disabled");
+ return -EINVAL;
+}
+
static inline int regmap_bulk_write(struct regmap *map, unsigned int reg,
const void *val, size_t val_count)
{
--
2.7.4