On Fri, Aug 03, 2018 at 04:02:18PM +0300, Stefan Popa wrote:
> From: Crestez Dan Leonard <leonard.crestez@xxxxxxxxx>
>
> The regmap API usually assumes that bulk read operations will read a
> range of registers but some I2C/SPI devices have certain registers for
> which a such a read operation will return data from an internal FIFO
> instead. Add an explicit API to support bulk read without range semantics.
>
> Some linux drivers use regmap_bulk_read or regmap_raw_read for such
> registers, for example mpu6050 or bmi150 from IIO. This only happens to
> work because when caching is disabled a single regmap read op will map
> to a single bus read op (as desired). This breaks if caching is enabled and
> reg+1 happens to be a cacheable register.
>
> Without regmap support refactoring a driver to enable regmap caching
> requires separate I2C and SPI paths. This is exactly what regmap is
> supposed to help avoid.
>
> Suggested-by: Jonathan Cameron <jic23@xxxxxxxxxx>
> Signed-off-by: Crestez Dan Leonard <leonard.crestez@xxxxxxxxx>
> Signed-off-by: Stefan Popa <stefan.popa@xxxxxxxxxx>
> ---
> diff --git a/include/linux/regmap.h b/include/linux/regmap.h
> index 4f38068..b6e6040 100644
> --- a/include/linux/regmap.h
> +++ b/include/linux/regmap.h
> @@ -946,6 +946,8 @@ int regmap_raw_write_async(struct regmap *map, unsigned int reg,
> int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val);
> int regmap_raw_read(struct regmap *map, unsigned int reg,
> void *val, size_t val_len);
> +int regmap_noinc_read(struct regmap *map, unsigned int reg,
> + void *val, size_t val_len);
> int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
> size_t val_count);
> int regmap_update_bits_base(struct regmap *map, unsigned int reg,
> @@ -1196,6 +1198,13 @@ static inline int regmap_raw_read(struct regmap *map, unsigned int reg,
> return -EINVAL;
> }
>
> +static inline int regmap_pipe_read(struct regmap *map, unsigned int reg,
> + void *val, size_t val_len)
> +{
> + WARN_ONCE(1, "regmap API is disabled");
> + return -EINVAL;
> +}
> +
This is presumably supposed to be regmap_noinc_read.
Thanks,
Charles
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