[PATCH] thermal: intel_pch_thermal: Read large temp values correctly

[PATCH] thermal: intel_pch_thermal: Read large temp values correctly

[Ed Swierk]

On all supported platforms, the TS Reading (TSR) field in the
Temperature (TEMP) register is 9 bits wide. Values above 0x100 (78
degrees C) are plausible, so don't mask out the topmost bit. And the
register itself is 16 bits wide, so use readw() rather than readl().

Signed-off-by: Ed Swierk <eswierk@skyportsystems.com>
---
 drivers/thermal/intel_pch_thermal.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/thermal/intel_pch_thermal.c b/drivers/thermal/intel_pch_thermal.c
index 9889c90..318fc1b 100644
--- a/drivers/thermal/intel_pch_thermal.c
+++ b/drivers/thermal/intel_pch_thermal.c
@@ -49,7 +49,7 @@
 #define WPT_TSGPEN	0x84	/* General Purpose Event Enables */
 
 /*  Wildcat Point-LP  PCH Thermal Register bit definitions */
-#define WPT_TEMP_TSR	0x00ff	/* Temp TS Reading */
+#define WPT_TEMP_TSR	0x01ff	/* Temp TS Reading */
 #define WPT_TSC_CPDE	0x01	/* Catastrophic Power-Down Enable */
 #define WPT_TSS_TSDSS	0x10	/* Thermal Sensor Dynamic Shutdown Status */
 #define WPT_TSS_GPES	0x08	/* GPE status */
@@ -174,9 +174,9 @@ static int pch_wpt_init(struct pch_thermal_device *ptd, int *nr_trips)
 
 static int pch_wpt_get_temp(struct pch_thermal_device *ptd, int *temp)
 {
-	u8 wpt_temp;
+	u16 wpt_temp;
 
-	wpt_temp = WPT_TEMP_TSR & readl(ptd->hw_base + WPT_TEMP);
+	wpt_temp = WPT_TEMP_TSR & readw(ptd->hw_base + WPT_TEMP);
 
 	/* Resolution of 1/2 degree C and an offset of -50C */
 	*temp = (wpt_temp * 1000 / 2 - 50000);
-- 
1.9.1

Re: [PATCH] thermal: intel_pch_thermal: Read large temp values correctly

[Srinivas Pandruvada]

On Wed, 2017-07-19 at 17:47 -0700, Ed Swierk wrote:
> On all supported platforms, the TS Reading (TSR) field in the
> Temperature (TEMP) register is 9 bits wide. Values above 0x100 (78
> degrees C) are plausible, so don't mask out the topmost bit. And the
> register itself is 16 bits wide, so use readw() rather than readl().
> 
> Signed-off-by: Ed Swierk <eswierk@skyportsystems.com>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

> ---
>  drivers/thermal/intel_pch_thermal.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/thermal/intel_pch_thermal.c
> b/drivers/thermal/intel_pch_thermal.c
> index 9889c90..318fc1b 100644
> --- a/drivers/thermal/intel_pch_thermal.c
> +++ b/drivers/thermal/intel_pch_thermal.c
> @@ -49,7 +49,7 @@
>  #define WPT_TSGPEN	0x84	/* General Purpose Event
> Enables */
>  
>  /*  Wildcat Point-LP  PCH Thermal Register bit definitions */
> -#define WPT_TEMP_TSR	0x00ff	/* Temp TS Reading */
> +#define WPT_TEMP_TSR	0x01ff	/* Temp TS Reading */
>  #define WPT_TSC_CPDE	0x01	/* Catastrophic Power-Down
> Enable */
>  #define WPT_TSS_TSDSS	0x10	/* Thermal Sensor Dynamic
> Shutdown Status */
>  #define WPT_TSS_GPES	0x08	/* GPE status */
> @@ -174,9 +174,9 @@ static int pch_wpt_init(struct pch_thermal_device
> *ptd, int *nr_trips)
>  
>  static int pch_wpt_get_temp(struct pch_thermal_device *ptd, int
> *temp)
>  {
> -	u8 wpt_temp;
> +	u16 wpt_temp;
>  
> -	wpt_temp = WPT_TEMP_TSR & readl(ptd->hw_base + WPT_TEMP);
> +	wpt_temp = WPT_TEMP_TSR & readw(ptd->hw_base + WPT_TEMP);
>  
>  	/* Resolution of 1/2 degree C and an offset of -50C */
>  	*temp = (wpt_temp * 1000 / 2 - 50000);