Nishanth Menon <nm@xxxxxx> writes:
> From: Patrick Titiano <p-titiano@xxxxxx>
>
> omap_twl_vsel_to_uv() and omap_twl_uv_to_vsel() functions used to convert
> voltages to TWL6030 SMPS commands (a.k.a "vsel") implement incorrect conversion
> formula.
> It uses legacy OMAP3 formula, but OMAP4 Power IC has different offset and
> voltage step:
> - Voltage Step is now 12.66mV (instead of 12.5mV)
> - Offset is either 607.7mV or 709mV depending on TWL6030 chip revision
> (instead of 600mV)
> This leads to setting voltages potentially higher than expected, and so
> potentially some (limited) power overconsumption.
>
> For reference, see formula and tables in section 8.5.2.3
> "Output Voltage Selection (Standard Mode / Extended Mode with or without offset)"
> in TWL6030 functional specifications document.
>
> [nm@xxxxxx: ported to voltdm_c]
> Signed-off-by: Nishanth Menon <nm@xxxxxx>
> Signed-off-by: Patrick Titiano <p-titiano@xxxxxx>
Thanks, adding to voltdm queue.
Kevin
> ---
> arch/arm/mach-omap2/omap_twl.c | 14 +++++++-------
> 1 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/omap_twl.c b/arch/arm/mach-omap2/omap_twl.c
> index 82a91be..78fd985 100644
> --- a/arch/arm/mach-omap2/omap_twl.c
> +++ b/arch/arm/mach-omap2/omap_twl.c
> @@ -106,9 +106,9 @@ static unsigned long twl6030_vsel_to_uv(const u8 vsel)
> return 1350000;
>
> if (smps_offset & 0x8)
> - return ((((vsel - 1) * 125) + 7000)) * 100;
> + return ((((vsel - 1) * 1266) + 70900)) * 10;
> else
> - return ((((vsel - 1) * 125) + 6000)) * 100;
> + return ((((vsel - 1) * 1266) + 60770)) * 10;
> }
>
> static u8 twl6030_uv_to_vsel(unsigned long uv)
> @@ -138,9 +138,9 @@ static u8 twl6030_uv_to_vsel(unsigned long uv)
> return 0x3A;
>
> if (smps_offset & 0x8)
> - return DIV_ROUND_UP(uv - 700000, 12500) + 1;
> + return DIV_ROUND_UP(uv - 709000, 12660) + 1;
> else
> - return DIV_ROUND_UP(uv - 600000, 12500) + 1;
> + return DIV_ROUND_UP(uv - 607700, 12660) + 1;
> }
>
> static struct omap_voltdm_pmic omap3_mpu_pmic = {
> @@ -187,7 +187,7 @@ static struct omap_voltdm_pmic omap3_core_pmic = {
>
> static struct omap_voltdm_pmic omap4_mpu_pmic = {
> .slew_rate = 4000,
> - .step_size = 12500,
> + .step_size = 12660,
> .on_volt = 1350000,
> .onlp_volt = 1350000,
> .ret_volt = 837500,
> @@ -212,7 +212,7 @@ static struct omap_voltdm_pmic omap4_mpu_pmic = {
>
> static struct omap_voltdm_pmic omap4_iva_pmic = {
> .slew_rate = 4000,
> - .step_size = 12500,
> + .step_size = 12660,
> .on_volt = 1100000,
> .onlp_volt = 1100000,
> .ret_volt = 837500,
> @@ -237,7 +237,7 @@ static struct omap_voltdm_pmic omap4_iva_pmic = {
>
> static struct omap_voltdm_pmic omap4_core_pmic = {
> .slew_rate = 4000,
> - .step_size = 12500,
> + .step_size = 12660,
> .on_volt = 1100000,
> .onlp_volt = 1100000,
> .ret_volt = 837500,
--
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