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

[Stephen Barber]

On Wed, Jul 27, 2016 at 7:10 AM, Caesar Wang <wxt at rock-chips.com> wrote:
> From: Rocky Hao <rocky.hao at rock-chips.com>
>
> 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 at rock-chips.com>
> Signed-off-by: Caesar Wang <wxt at rock-chips.com>
> Cc: Eduardo Valentin <edubezval at gmail.com>
> Cc: Zhang Rui <rui.zhang at intel.com>
> Cc: Heiko Stuebner <heiko at sntech.de>
> Cc: linux-pm at vger.kernel.org
> ---
>
>  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 at chromium.org>

Steve