Re: [PATCHv3 3/3] staging: ti-soc-thermal: remove external heat while extrapolating hotspot

[Zhang Rui <rui.zhang@intel.com>]

On Fri, 2013-04-05 at 08:32 -0400, Eduardo Valentin wrote:
> For boards that provide a PCB sensor close to SoC junction
> temperature, it is possible to remove the cumulative heat
> reported by the SoC temperature sensor.
> 
> This patch changes the extrapolation computation to consider
> an external sensor in the extrapolation equations.
> 
> Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>

hmm, who should take this patch?

thanks,
rui
> ---
>  drivers/staging/ti-soc-thermal/ti-thermal-common.c |   30 +++++++++++++------
>  1 files changed, 20 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/staging/ti-soc-thermal/ti-thermal-common.c b/drivers/staging/ti-soc-thermal/ti-thermal-common.c
> index 231c549..780368b 100644
> --- a/drivers/staging/ti-soc-thermal/ti-thermal-common.c
> +++ b/drivers/staging/ti-soc-thermal/ti-thermal-common.c
> @@ -38,6 +38,7 @@
>  /* common data structures */
>  struct ti_thermal_data {
>  	struct thermal_zone_device *ti_thermal;
> +	struct thermal_zone_device *pcb_tz;
>  	struct thermal_cooling_device *cool_dev;
>  	struct ti_bandgap *bgp;
>  	enum thermal_device_mode mode;
> @@ -77,10 +78,12 @@ static inline int ti_thermal_hotspot_temperature(int t, int s, int c)
>  static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
>  				      unsigned long *temp)
>  {
> +	struct thermal_zone_device *pcb_tz = NULL;
>  	struct ti_thermal_data *data = thermal->devdata;
>  	struct ti_bandgap *bgp;
>  	const struct ti_temp_sensor *s;
> -	int ret, tmp, pcb_temp, slope, constant;
> +	int ret, tmp, slope, constant;
> +	unsigned long pcb_temp;
>  
>  	if (!data)
>  		return 0;
> @@ -92,16 +95,22 @@ static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
>  	if (ret)
>  		return ret;
>  
> -	pcb_temp = 0;
> -	/* TODO: Introduce pcb temperature lookup */
> +	/* Default constants */
> +	slope = s->slope;
> +	constant = s->constant;
> +
> +	pcb_tz = data->pcb_tz;
>  	/* In case pcb zone is available, use the extrapolation rule with it */
> -	if (pcb_temp) {
> -		tmp -= pcb_temp;
> -		slope = s->slope_pcb;
> -		constant = s->constant_pcb;
> -	} else {
> -		slope = s->slope;
> -		constant = s->constant;
> +	if (!IS_ERR_OR_NULL(pcb_tz)) {
> +		ret = thermal_zone_get_temp(pcb_tz, &pcb_temp);
> +		if (!ret) {
> +			tmp -= pcb_temp; /* got a valid PCB temp */
> +			slope = s->slope_pcb;
> +			constant = s->constant_pcb;
> +		} else {
> +			dev_err(bgp->dev,
> +				"Failed to read PCB state. Using defaults\n");
> +		}
>  	}
>  	*temp = ti_thermal_hotspot_temperature(tmp, slope, constant);
>  
> @@ -248,6 +257,7 @@ static struct ti_thermal_data
>  	data->sensor_id = id;
>  	data->bgp = bgp;
>  	data->mode = THERMAL_DEVICE_ENABLED;
> +	data->pcb_tz = thermal_zone_get_zone_by_name("pcb");
>  	INIT_WORK(&data->thermal_wq, ti_thermal_work);
>  
>  	return data;