[PATCH] nvmem: regmap: Fix nvmem size

[PATCH] nvmem: regmap: Fix nvmem size

[Robin van der Gracht]

We should add 1 to the max_register index since counting is zero based.

i.e. the stm32mp151 bsec has registers 0 - 95 with reg_stride 4.
Size should be (95 + 1) * 4 = 384 bytes otherwise we can't access bsec
register 95 (last one).

Signed-off-by: Robin van der Gracht <robin@protonic.nl>
---
 drivers/nvmem/regmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvmem/regmap.c b/drivers/nvmem/regmap.c
index fa5405d7a8..ffc96a310f 100644
--- a/drivers/nvmem/regmap.c
+++ b/drivers/nvmem/regmap.c
@@ -78,7 +78,7 @@ nvmem_regmap_register_with_pp(struct regmap *map, const char *name,
 	config.priv = map;
 	config.stride = 1;
 	config.word_size = 1;
-	config.size = regmap_get_max_register(map) * regmap_get_reg_stride(map);
+	config.size = (regmap_get_max_register(map) + 1) * regmap_get_reg_stride(map);
 	config.cell_post_process = cell_post_process;
 	config.reg_write = nvmem_regmap_write;
 	config.reg_read = nvmem_regmap_read;
-- 
2.40.1

Re: [PATCH] nvmem: regmap: Fix nvmem size

[Robin van der Gracht]

After applying this patch the last register is writable, but still not 
readable.

The size is now correct:
barebox:/ ls -l /dev/stm32-bsec
crw-------            384 /dev/stm32-bsec

This now works:
mw -l -d /dev/stm32-bsec 0x0000017c+4 0x12345678

This still doesn't:
barebox:/ md -l -s /dev/stm32-bsec 0x0000017c+4
read: Invalid argument

On 2023-12-19 15:14, Robin van der Gracht wrote:
> We should add 1 to the max_register index since counting is zero based.
> 
> i.e. the stm32mp151 bsec has registers 0 - 95 with reg_stride 4.
> Size should be (95 + 1) * 4 = 384 bytes otherwise we can't access bsec
> register 95 (last one).
> 
> Signed-off-by: Robin van der Gracht <robin@protonic.nl>
> ---
>  drivers/nvmem/regmap.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/nvmem/regmap.c b/drivers/nvmem/regmap.c
> index fa5405d7a8..ffc96a310f 100644
> --- a/drivers/nvmem/regmap.c
> +++ b/drivers/nvmem/regmap.c
> @@ -78,7 +78,7 @@ nvmem_regmap_register_with_pp(struct regmap *map,
> const char *name,
>  	config.priv = map;
>  	config.stride = 1;
>  	config.word_size = 1;
> -	config.size = regmap_get_max_register(map) * 
> regmap_get_reg_stride(map);
> +	config.size = (regmap_get_max_register(map) + 1) * 
> regmap_get_reg_stride(map);
>  	config.cell_post_process = cell_post_process;
>  	config.reg_write = nvmem_regmap_write;
>  	config.reg_read = nvmem_regmap_read;