[U-Boot] [PATCH v6 08/14] regmap: Add raw read/write functions
Simon Glass
sjg at chromium.org
Fri Aug 17 12:48:29 UTC 2018
Hi Mario,
On 13 August 2018 at 00:09, Mario Six <mario.six at gdsys.cc> wrote:
> The regmap functions currently assume that all register map accesses
> have a data width of 32 bits, but there are maps that have different
> widths.
>
> To rectify this, implement the regmap_raw_read and regmap_raw_write
> functions from the Linux kernel API that specify the width of a desired
> read or write operation on a regmap.
>
> Implement the regmap_read and regmap_write functions using these raw
> functions in a backwards-compatible manner.
>
> Reviewed-by: Anatolij Gustschin <agust at denx.de>
> Signed-off-by: Mario Six <mario.six at gdsys.cc>
>
> ---
>
> v5 -> v6:
> * Corrected format specifier
> * Added support for 64-bit reads/writes
>
> v4 -> v5:
> No changes
>
> v3 -> v4:
> * Switched 'ranges[0] + offset' to 'ranges[0].start + offset'
> * Explained the difference between the raw and non-raw read/write
> functions better in the docs
>
> v2 -> v3:
> * Implement the "raw" functions from Linux instead of adding a size
> parameter to the regmap_{read,write} functions
> * Fixed style violation
> * Improved error handling
>
> v1 -> v2:
> New in v2
>
> ---
> drivers/core/regmap.c | 59 +++++++++++++++++++++++++++++++++++++++++++++------
> include/regmap.h | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 110 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/core/regmap.c b/drivers/core/regmap.c
> index 154426269d9..a2f82091af0 100644
> --- a/drivers/core/regmap.c
> +++ b/drivers/core/regmap.c
> @@ -188,22 +188,67 @@ int regmap_uninit(struct regmap *map)
> return 0;
> }
>
> +int regmap_raw_read(struct regmap *map, uint offset, void *valp, size_t val_len)
> +{
> + void *ptr;
> +
> + ptr = map_physmem(map->ranges[0].start + offset, val_len, MAP_NOCACHE);
> +
> + switch (val_len) {
> + case REGMAP_SIZE_8:
> + *((u8 *)valp) = in_8((u8 *)ptr);
> + break;
> + case REGMAP_SIZE_16:
> + *((u16 *)valp) = in_le16((u16 *)ptr);
> + break;
> + case REGMAP_SIZE_32:
> + *((u32 *)valp) = in_le32((u32 *)ptr);
> + break;
> +#if defined(in_le64) && defined(readq)
> + case REGMAP_SIZE_64:
> + *((u32 *)valp) = in_le64((u64 *)ptr);
How come this is u32? Can you please add a comment?
Why is this using in/out rather than read/write? Does it not support
memory-mapped I/O?
> + break;
> +#endif
> + default:
> + debug("%s: regmap size %zu unknown\n", __func__, val_len);
> + return -EINVAL;
> + }
> + return 0;
> +}
> +
> int regmap_read(struct regmap *map, uint offset, uint *valp)
> {
> - u32 *ptr = map_physmem(map->ranges[0].start + offset, 4, MAP_NOCACHE);
> + return regmap_raw_read(map, offset, valp, REGMAP_SIZE_32);
> +}
>
> - *valp = le32_to_cpu(readl(ptr));
> +int regmap_raw_write(struct regmap *map, uint offset, const void *val,
> + size_t val_len)
> +{
> + void *ptr;
> +
> + ptr = map_physmem(map->ranges[0].start + offset, val_len, MAP_NOCACHE);
> +
> + switch (val_len) {
> + case REGMAP_SIZE_8:
> + out_8((u8 *)ptr, *((u8 *)val));
> + break;
> + case REGMAP_SIZE_16:
> + out_le16((u16 *)ptr, *((u16 *)val));
> + break;
> + case REGMAP_SIZE_32:
> + out_le32((u32 *)ptr, *((u32 *)val));
> + break;
No 64-bit?
> + default:
> + debug("%s: regmap size %zu unknown\n", __func__, val_len);
> + return -EINVAL;
> + }
>
> return 0;
> }
>
> int regmap_write(struct regmap *map, uint offset, uint val)
> {
> - u32 *ptr = map_physmem(map->ranges[0].start + offset, 4, MAP_NOCACHE);
> -
> - writel(cpu_to_le32(val), ptr);
> -
> - return 0;
> + return regmap_raw_write(map, offset, &val, REGMAP_SIZE_32);
> }
>
> int regmap_update_bits(struct regmap *map, uint offset, uint mask, uint val)
> diff --git a/include/regmap.h b/include/regmap.h
> index 32f75e06f59..8a9759281a5 100644
> --- a/include/regmap.h
> +++ b/include/regmap.h
> @@ -8,6 +8,21 @@
> #define __REGMAP_H
>
> /**
> + * enum regmap_size_t - Access sizes for fpgamap reads and writes
> + *
> + * @REGMAP_SIZE_8: 8-bit read/write access size
> + * @REGMAP_SIZE_16: 16-bit read/write access size
> + * @REGMAP_SIZE_32: 32-bit read/write access size
> + * @REGMAP_SIZE_64: 64-bit read/write access size
> + */
> +enum regmap_size_t {
> + REGMAP_SIZE_8 = 1,
> + REGMAP_SIZE_16 = 2,
> + REGMAP_SIZE_32 = 4,
> + REGMAP_SIZE_64 = 8,
> +};
> +
> +/**
> * struct regmap_range - a register map range
> *
> * @start: Start address
> @@ -41,6 +56,10 @@ struct regmap {
> * @offset: Offset in the regmap to write to
> * @val: Data to write to the regmap at the specified offset
> *
> + * Note that this function will only write values of 32 bit width to the
> + * regmap; if the size of data to be read is different, the regmap_raw_write
> + * function can be used.
> + *
> * Return: 0 if OK, -ve on error
> */
> int regmap_write(struct regmap *map, uint offset, uint val);
> @@ -53,10 +72,49 @@ int regmap_write(struct regmap *map, uint offset, uint val);
> * @valp: Pointer to the buffer to receive the data read from the regmap
> * at the specified offset
> *
> + * Note that this function will only read values of 32 bit width from the
> + * regmap; if the size of data to be read is different, the regmap_raw_read
> + * function can be used.
> + *
> * Return: 0 if OK, -ve on error
> */
> int regmap_read(struct regmap *map, uint offset, uint *valp);
>
> +/**
> + * regmap_raw_write() - Write a value of specified length to a regmap
> + *
> + * @map: Regmap to write to
> + * @offset: Offset in the regmap to write to
> + * @val: Value to write to the regmap at the specified offset
> + * @val_len: Length of the data to be written to the regmap
> + *
> + * Note that this function will, as opposed to regmap_write, write data of
> + * arbitrary length to the regmap, and not just 32-bit values, and is thus a
> + * generalized version of regmap_write.
> + *
> + * Return: 0 if OK, -ve on error
> + */
> +int regmap_raw_write(struct regmap *map, uint offset, const void *val,
> + size_t val_len);
> +
> +/**
> + * regmap_raw_read() - Read a value of specified length from a regmap
> + *
> + * @map: Regmap to read from
> + * @offset: Offset in the regmap to read from
> + * @valp: Pointer to the buffer to receive the data read from the regmap
> + * at the specified offset
> + * @val_len: Length of the data to be read from the regmap
> + *
> + * Note that this function will, as opposed to regmap_read, read data of
> + * arbitrary length from the regmap, and not just 32-bit values, and is thus a
> + * generalized version of regmap_read.
> + *
> + * Return: 0 if OK, -ve on error
> + */
> +int regmap_raw_read(struct regmap *map, uint offset, void *valp,
> + size_t val_len);
> +
> #define regmap_write32(map, ptr, member, val) \
> regmap_write(map, (uint32_t *)(ptr)->member - (uint32_t *)(ptr), val)
>
> --
> 2.11.0
>
Regards,
Simon
More information about the U-Boot
mailing list