On 29-08-2022 23:00, Dixit, Ashutosh wrote:
On Thu, 25 Aug 2022 06:21:13 -0700, Badal Nilawar wrote:
From: Riana Tauro <riana.tauro@xxxxxxxxx>
Use i915 HWMON subsystem to display current input voltage.
A couple of suggestions to improve comments in this patch below and after
addressing those this patch is:
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx>
diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
index 103dd543a214..2192d0fd4c66 100644
--- a/drivers/gpu/drm/i915/i915_hwmon.c
+++ b/drivers/gpu/drm/i915/i915_hwmon.c
@@ -11,8 +11,10 @@
#include "i915_hwmon.h"
#include "i915_reg.h"
#include "intel_mchbar_regs.h"
+#include "gt/intel_gt_regs.h"
In later patches we have added units for different quantities here. So I
think we should add those units for voltage to this patch too. It's in
Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon but I think it's
better to add to this file too otherwise if anyone looks at it is seems to
be missing.
So I would add the following to this patch:
/*
* SF_* - scale factors for particular quantities according to hwmon spec.
* - voltage - millivolts
*/
Sure I will add above comment.
#define SF_VOLTAGE 1000
we are not using above scale factor for voltage. As our scale factor is
2.5 millivolts shall I add like.
#define SF_VOLTAGE_MUL 25
#define SF_VOLTAGE_DIV 10
+static int
+hwm_in_read(struct hwm_drvdata *ddat, u32 attr, long *val)
+{
+ struct i915_hwmon *hwmon = ddat->hwmon;
+ intel_wakeref_t wakeref;
+ u32 reg_value;
+
+ switch (attr) {
+ case hwmon_in_input:
+ with_intel_runtime_pm(ddat->uncore->rpm, wakeref)
+ reg_value = intel_uncore_read(ddat->uncore, hwmon->rg.gt_perf_status);
+ /* In units of 2.5 millivolt */
+ *val = DIV_ROUND_CLOSEST(REG_FIELD_GET(GEN12_VOLTAGE_MASK, reg_value) * 25, 10);
And use above scale factors here.
*val = DIV_ROUND_CLOSEST(REG_FIELD_GET(GEN12_VOLTAGE_MASK, reg_value) *
SF_VOLTAGE_MUL, SF_VOLTAGE_DIV);
Regards,
Badal
Let's complete this comment to so that it is clear what's happening:
/* HW register value is in units of 2.5 millivolt */
