Re: [PATCH 1/2] thermal: rockchip: enhance the tsadc's bandgap feature for rk3399

From: Stephen Barber
Date: Thu Jul 28 2016 - 17:53:27 EST


On Wed, Jul 27, 2016 at 7:10 AM, Caesar Wang <wxt@xxxxxxxxxxxxxx> wrote:
> From: Rocky Hao <rocky.hao@xxxxxxxxxxxxxx>
>
> Due to the voltage ripple, the sensing data of the tsadc is not accurate.
> And in this patch, the bandgap feature is enhanced to remove the voltage
> ripple, and then the tsadc can sense the temperature more precisely.
>
> Obsolete codes are removed as well.
>
> Signed-off-by: Rocky Hao <rocky.hao@xxxxxxxxxxxxxx>
> Signed-off-by: Caesar Wang <wxt@xxxxxxxxxxxxxx>
> Cc: Eduardo Valentin <edubezval@xxxxxxxxx>
> Cc: Zhang Rui <rui.zhang@xxxxxxxxx>
> Cc: Heiko Stuebner <heiko@xxxxxxxxx>
> Cc: linux-pm@xxxxxxxxxxxxxxx
> ---
>
> drivers/thermal/rockchip_thermal.c | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c
> index db5ecc5..a90423d 100644
> --- a/drivers/thermal/rockchip_thermal.c
> +++ b/drivers/thermal/rockchip_thermal.c
> @@ -222,10 +222,10 @@ struct rockchip_thermal_data {
> #define GRF_TSADC_TESTBIT_L 0x0e648
> #define GRF_TSADC_TESTBIT_H 0x0e64c
>
> -#define GRF_TSADC_TSEN_PD_ON (0x30003 << 0)
> -#define GRF_TSADC_TSEN_PD_OFF (0x30000 << 0)
> #define GRF_SARADC_TESTBIT_ON (0x10001 << 2)
> #define GRF_TSADC_TESTBIT_H_ON (0x10001 << 2)
> +#define GRF_TSADC_VCM_EN_L (0x10001 << 7)
> +#define GRF_TSADC_VCM_EN_H (0x10001 << 7)
>
> /**
> * struct tsadc_table - code to temperature conversion table
> @@ -567,9 +567,10 @@ static void rk_tsadcv3_initialize(struct regmap *grf, void __iomem *regs,
> regs + TSADCV2_HIGHT_TSHUT_DEBOUNCE);
>
> } else {
> - regmap_write(grf, GRF_TSADC_TESTBIT_L, GRF_TSADC_TSEN_PD_ON);
> - mdelay(10);
> - regmap_write(grf, GRF_TSADC_TESTBIT_L, GRF_TSADC_TSEN_PD_OFF);
> + /* Enable the voltage common mode feature */
> + regmap_write(grf, GRF_TSADC_TESTBIT_L, GRF_TSADC_VCM_EN_L);
> + regmap_write(grf, GRF_TSADC_TESTBIT_H, GRF_TSADC_VCM_EN_H);
> +
> usleep_range(15, 100); /* The spec note says at least 15 us */
> regmap_write(grf, GRF_SARADC_TESTBIT, GRF_SARADC_TESTBIT_ON);
> regmap_write(grf, GRF_TSADC_TESTBIT_H, GRF_TSADC_TESTBIT_H_ON);
> --
> 1.9.1
>

Tested-by: Stephen Barber <smbarber@xxxxxxxxxxxx>

Steve