[U-Boot] [PATCH] sunxi: axp209: fix incorrect limits on ldo3

[U-Boot] [PATCH] sunxi: axp209: fix incorrect limits on ldo3

[Iain Paton]

board/sunxi/board.c tries to set ldo3 to 2.8v however drivers/power/axp209.c
contains an incorrect limit on ldo3 of 2.275v

The origin of the incorrect limit seems likely due to some inconsistencies
in the axp209 datasheet. ldo3 is described with different limits in 
different sections. register 0x29 uses 7 bits for voltage configuration
while the 2.275v limit would apply if only 6 bits were used.
Probably this is a cut&paste error from register 0x23

The linux kernel driver has the correct limit and operation up to the 2.8v
required by my board has been physically verified with a multimeter.

Signed-off-by: Iain Paton <ipaton0@gmail.com>
---
 drivers/power/axp209.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/power/axp209.c b/drivers/power/axp209.c
index 4565398..f8c9b77 100644
--- a/drivers/power/axp209.c
+++ b/drivers/power/axp209.c
@@ -119,7 +119,7 @@ int axp209_set_ldo3(int mvolt)
 	if (mvolt == -1)
 		cfg = 0x80;	/* determined by LDO3IN pin */
 	else
-		cfg = axp209_mvolt_to_cfg(mvolt, 700, 2275, 25);
+		cfg = axp209_mvolt_to_cfg(mvolt, 700, 3500, 25);
 
 	return axp209_write(AXP209_LDO3_VOLTAGE, cfg);
 }
-- 
2.1.3

[U-Boot] [PATCH] sunxi: axp209: fix incorrect limits on ldo3

[Hans de Goede]

Hi,

On 25-03-15 17:03, Iain Paton wrote:
> board/sunxi/board.c tries to set ldo3 to 2.8v however drivers/power/axp209.c
> contains an incorrect limit on ldo3 of 2.275v
>
> The origin of the incorrect limit seems likely due to some inconsistencies
> in the axp209 datasheet. ldo3 is described with different limits in
> different sections. register 0x29 uses 7 bits for voltage configuration
> while the 2.275v limit would apply if only 6 bits were used.
> Probably this is a cut&paste error from register 0x23
>
> The linux kernel driver has the correct limit and operation up to the 2.8v
> required by my board has been physically verified with a multimeter.
>
> Signed-off-by: Iain Paton <ipaton0@gmail.com>

Thanks, I've merged this into u-boot-sunxi/master and added this
in a small fixed pull-req which I've just send.

Regards,

Hans

> ---
>   drivers/power/axp209.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/power/axp209.c b/drivers/power/axp209.c
> index 4565398..f8c9b77 100644
> --- a/drivers/power/axp209.c
> +++ b/drivers/power/axp209.c
> @@ -119,7 +119,7 @@ int axp209_set_ldo3(int mvolt)
>   	if (mvolt == -1)
>   		cfg = 0x80;	/* determined by LDO3IN pin */
>   	else
> -		cfg = axp209_mvolt_to_cfg(mvolt, 700, 2275, 25);
> +		cfg = axp209_mvolt_to_cfg(mvolt, 700, 3500, 25);
>
>   	return axp209_write(AXP209_LDO3_VOLTAGE, cfg);
>   }
>