On Wed, Jan 15, 2020 at 12:36 AM Florian Fainelli <f.fainelli@xxxxxxxxx> wrote:
>
> At the time the brcmstb_thermal driver and its binding were merged, the
> DT binding did not make the coefficients properties a mandatory one,
> therefore all users of the brcmstb_thermal driver out there have a non
> functional implementation with zero coefficients. Even if these
> properties were provided, the formula used for computation is incorrect.
>
> The coefficients are entirely process specific (right now, only 28nm is
> supported) and not board or SoC specific, it is therefore appropriate to
> hard code them in the driver given the compatibility string we are
> probed with which has to be updated whenever a new process is
> introduced.
>
> We remove the existing coefficients definition since subsequent patches
> are going to add support for a new process and will introduce new
> coefficients as well.
>
> Fixes: 9e03cf1b2dd5 ("thermal: add brcmstb AVS TMON driver")
> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Reviewed-by: Amit Kucheria <amit.kucheria@xxxxxxxxxx>
> ---
> drivers/thermal/broadcom/brcmstb_thermal.c | 31 +++++++---------------
> 1 file changed, 9 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/thermal/broadcom/brcmstb_thermal.c b/drivers/thermal/broadcom/brcmstb_thermal.c
> index 5825ac581f56..680f1a070606 100644
> --- a/drivers/thermal/broadcom/brcmstb_thermal.c
> +++ b/drivers/thermal/broadcom/brcmstb_thermal.c
> @@ -49,7 +49,7 @@
> #define AVS_TMON_TP_TEST_ENABLE 0x20
>
> /* Default coefficients */
> -#define AVS_TMON_TEMP_SLOPE -487
> +#define AVS_TMON_TEMP_SLOPE 487
> #define AVS_TMON_TEMP_OFFSET 410040
>
> /* HW related temperature constants */
> @@ -108,23 +108,12 @@ struct brcmstb_thermal_priv {
> struct thermal_zone_device *thermal;
> };
>
> -static void avs_tmon_get_coeffs(struct thermal_zone_device *tz, int *slope,
> - int *offset)
> -{
> - *slope = thermal_zone_get_slope(tz);
> - *offset = thermal_zone_get_offset(tz);
> -}
> -
> /* Convert a HW code to a temperature reading (millidegree celsius) */
> static inline int avs_tmon_code_to_temp(struct thermal_zone_device *tz,
> u32 code)
> {
> - const int val = code & AVS_TMON_TEMP_MASK;
> - int slope, offset;
> -
> - avs_tmon_get_coeffs(tz, &slope, &offset);
> -
> - return slope * val + offset;
> + return (AVS_TMON_TEMP_OFFSET -
> + (int)((code & AVS_TMON_TEMP_MAX) * AVS_TMON_TEMP_SLOPE));
> }
>
> /*
> @@ -136,20 +125,18 @@ static inline int avs_tmon_code_to_temp(struct thermal_zone_device *tz,
> static inline u32 avs_tmon_temp_to_code(struct thermal_zone_device *tz,
> int temp, bool low)
> {
> - int slope, offset;
> -
> if (temp < AVS_TMON_TEMP_MIN)
> - return AVS_TMON_TEMP_MAX; /* Maximum code value */
> -
> - avs_tmon_get_coeffs(tz, &slope, &offset);
> + return AVS_TMON_TEMP_MAX; /* Maximum code value */
>
> - if (temp >= offset)
> + if (temp >= AVS_TMON_TEMP_OFFSET)
> return 0; /* Minimum code value */
>
> if (low)
> - return (u32)(DIV_ROUND_UP(offset - temp, abs(slope)));
> + return (u32)(DIV_ROUND_UP(AVS_TMON_TEMP_OFFSET - temp,
> + AVS_TMON_TEMP_SLOPE));
> else
> - return (u32)((offset - temp) / abs(slope));
> + return (u32)((AVS_TMON_TEMP_OFFSET - temp) /
> + AVS_TMON_TEMP_SLOPE);
> }
>
> static int brcmstb_get_temp(void *data, int *temp)
> --
> 2.17.1
>
