[U-Boot] [PATCH v3 07/13] regmap: Add raw read/write functions

[Mario Six]

Hi Simon,

On Thu, Aug 2, 2018 at 2:20 PM, Simon Glass <sjg at chromium.org> wrote:
> Hi Mario,
>
> On 31 July 2018 at 04:01, 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.
>>
>> Signed-off-by: Mario Six <mario.six at gdsys.cc>
>> ---
>>
>> 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 | 54 ++++++++++++++++++++++++++++++++++++++++++++-------
>>  include/regmap.h      | 40 ++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 87 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/core/regmap.c b/drivers/core/regmap.c
>> index 3488361ee14..83ca19a08a4 100644
>> --- a/drivers/core/regmap.c
>> +++ b/drivers/core/regmap.c
>> @@ -188,22 +188,62 @@ 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] + 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;
>> +       default:
>> +               debug("%s: regmap size %u 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] + 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;
>> +       default:
>> +               debug("%s: regmap size %u 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..352851c715b 100644
>> --- a/include/regmap.h
>> +++ b/include/regmap.h
>> @@ -8,6 +8,19 @@
>>  #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
>> + */
>> +enum regmap_size_t {
>> +       REGMAP_SIZE_8 = 1,
>> +       REGMAP_SIZE_16 = 2,
>> +       REGMAP_SIZE_32 = 4,
>> +};
>> +
>> +/**
>>   * struct regmap_range - a register map range
>>   *
>>   * @start:     Start address
>> @@ -57,6 +70,33 @@ int regmap_write(struct regmap *map, uint offset, uint val);
>>   */
>>  int regmap_read(struct regmap *map, uint offset, uint *valp);
>>
>> +/**
>> + * regmap_raw_write() - Write a value of specified length to a regmap
>> + *
>
> Please explain the meaning of 'raw' here. Also please update the
> non-raw ones to explain that meaning.
>

OK, I'll explain the difference in v4.

>> + * @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
>> + *
>> + * 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
>> + *
>
> Same here
>

Dito.

>> + * @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
>> + *
>> + * 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
>>

Best regards,
Mario