On 12/4/19 12:41 AM, Amit Kucheria wrote:
> On Wed, Oct 30, 2019 at 11:51 PM 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")
>
> I think you should fix the computation formula as the first patch and
> then merge the rest of this patch into your second patch.
>
> I don't think the intermediate state of converting named constants to
> magic numbers is needed just to convert it over to another set of
> parameters.
ok, so you would rather see this patch using the defined constants while
fixing the formula, and in a subsequent patch getting rid of the
constant names since they are going to be added to a per-process table,
does that sound reasonable?
>
> Regards,
> Amit
>
>> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
>> ---
>> drivers/thermal/broadcom/brcmstb_thermal.c | 37 ++++------------------
>> 1 file changed, 6 insertions(+), 31 deletions(-)
>>
>> diff --git a/drivers/thermal/broadcom/brcmstb_thermal.c b/drivers/thermal/broadcom/brcmstb_thermal.c
>> index 5825ac581f56..42482af0422e 100644
>> --- a/drivers/thermal/broadcom/brcmstb_thermal.c
>> +++ b/drivers/thermal/broadcom/brcmstb_thermal.c
>> @@ -48,15 +48,6 @@
>> #define AVS_TMON_TEMP_INT_CODE 0x1c
>> #define AVS_TMON_TP_TEST_ENABLE 0x20
>>
>> -/* Default coefficients */
>> -#define AVS_TMON_TEMP_SLOPE -487
>> -#define AVS_TMON_TEMP_OFFSET 410040
>> -
>> -/* HW related temperature constants */
>> -#define AVS_TMON_TEMP_MAX 0x3ff
>> -#define AVS_TMON_TEMP_MIN -88161
>> -#define AVS_TMON_TEMP_MASK AVS_TMON_TEMP_MAX
>> -
>> enum avs_tmon_trip_type {
>> TMON_TRIP_TYPE_LOW = 0,
>> TMON_TRIP_TYPE_HIGH,
>> @@ -108,23 +99,11 @@ 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 (410040 - (int)((code & 0x3FF) * 487));
>> }
>>
>> /*
>> @@ -136,20 +115,16 @@ 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);
>> + if (temp < -88161)
>> + return 0x3FF; /* Maximum code value */
>>
>> - if (temp >= offset)
>> + if (temp >= 410040)
>> return 0; /* Minimum code value */
>>
>> if (low)
>> - return (u32)(DIV_ROUND_UP(offset - temp, abs(slope)));
>> + return (u32)(DIV_ROUND_UP(410040 - temp, 487));
>> else
>> - return (u32)((offset - temp) / abs(slope));
>> + return (u32)((410040 - temp) / 487);
>> }
>>
>> static int brcmstb_get_temp(void *data, int *temp)
>> --
>> 2.17.1
>>
--
Florian
