From: Riana Tauro <riana.tauro@xxxxxxxxx>
Use i915 HWMON subsystem to display current input voltage.
v2:
- Updated date and kernel version in feature description
- Fixed review comments (Ashutosh)
v3: Use macro HWMON_CHANNEL_INFO to define hwmon channel (Guenter)
v4:
- Fixed review comments (Ashutosh)
- Use hwm_ prefix for static functions (Ashutosh)
v5: Added unit of voltage as millivolts (Ashutosh)
v6: KernelVersion: 6.2, Date: February 2023 in doc (Tvrtko)
v7: Change contact to intel-gfx (Rodrigo)
GEN12_RPSTAT1 is available for all Gen12+ (Andi)
Added Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
to MAINTAINERS
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Anshuman Gupta <anshuman.gupta@xxxxxxxxx>
Signed-off-by: Riana Tauro <riana.tauro@xxxxxxxxx>
Signed-off-by: Badal Nilawar <badal.nilawar@xxxxxxxxx>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx>
Acked-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx>
Reviewed-by: Anshuman Gupta <anshuman.gupta@xxxxxxxxx>
---
.../ABI/testing/sysfs-driver-intel-i915-hwmon | 7 +++
MAINTAINERS | 1 +
drivers/gpu/drm/i915/gt/intel_gt_regs.h | 3 ++
drivers/gpu/drm/i915/i915_hwmon.c | 53 +++++++++++++++++++
4 files changed, 64 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
diff --git a/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon b/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
new file mode 100644
index 0000000000000..5f4b136f08509
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
@@ -0,0 +1,7 @@
+What: /sys/devices/.../hwmon/hwmon<i>/in0_input
+Date: February 2023
+KernelVersion: 6.2
+Contact: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
+Description: RO. Current Voltage in millivolt.
+
+ Only supported for particular Intel i915 graphics platforms.
diff --git a/MAINTAINERS b/MAINTAINERS
index f07a8bf8744f9..7d57ede980940 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10144,6 +10144,7 @@ Q: http://patchwork.freedesktop.org/project/intel-gfx/
B: https://gitlab.freedesktop.org/drm/intel/-/wikis/How-to-file-i915-bugs
C: irc://irc.oftc.net/intel-gfx
T: git git://anongit.freedesktop.org/drm-intel
+F: Documentation/ABI/testing/sysfs-driver-intel-i915-hwmon
F: Documentation/gpu/i915.rst
F: drivers/gpu/drm/i915/
F: include/drm/i915*
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
index 7f79bbf978284..fcf5f9012852f 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
@@ -1519,6 +1519,9 @@
#define VLV_RENDER_C0_COUNT _MMIO(0x138118)
#define VLV_MEDIA_C0_COUNT _MMIO(0x13811c)
+#define GEN12_RPSTAT1 _MMIO(0x1381b4)
+#define GEN12_VOLTAGE_MASK REG_GENMASK(10, 0)
+
#define GEN11_GT_INTR_DW(x) _MMIO(0x190018 + ((x) * 4))
#define GEN11_CSME (31)
#define GEN11_GUNIT (28)
diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
index 231552fda374a..025399391ddcc 100644
--- a/drivers/gpu/drm/i915/i915_hwmon.c
+++ b/drivers/gpu/drm/i915/i915_hwmon.c
@@ -11,8 +11,16 @@
#include "i915_hwmon.h"
#include "i915_reg.h"
#include "intel_mchbar_regs.h"
+#include "gt/intel_gt_regs.h"
+
+/*
+ * SF_* - scale factors for particular quantities according to hwmon spec.
+ * - voltage - millivolts
+ */
+#define SF_VOLTAGE 1000
struct hwm_reg {
+ i915_reg_t gt_perf_status;
};
struct hwm_drvdata {
@@ -29,14 +37,51 @@ struct i915_hwmon {
};
static const struct hwmon_channel_info *hwm_info[] = {
+ HWMON_CHANNEL_INFO(in, HWMON_I_INPUT),
NULL
};
+static umode_t
+hwm_in_is_visible(const struct hwm_drvdata *ddat, u32 attr)
+{
+ struct drm_i915_private *i915 = ddat->uncore->i915;
+
+ switch (attr) {
+ case hwmon_in_input:
+ return IS_DG1(i915) || IS_DG2(i915) ? 0444 : 0;
+ default:
+ return 0;
+ }
+}
+
+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);
+ /* HW register value in units of 2.5 millivolt */
+ *val = DIV_ROUND_CLOSEST(REG_FIELD_GET(GEN12_VOLTAGE_MASK, reg_value) * 25, 10);
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
static umode_t
hwm_is_visible(const void *drvdata, enum hwmon_sensor_types type,
u32 attr, int channel)
{
+ struct hwm_drvdata *ddat = (struct hwm_drvdata *)drvdata;
+
switch (type) {
+ case hwmon_in:
+ return hwm_in_is_visible(ddat, attr);
default:
return 0;
}
@@ -46,7 +91,11 @@ static int
hwm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
int channel, long *val)
{
+ struct hwm_drvdata *ddat = dev_get_drvdata(dev);
+
switch (type) {
+ case hwmon_in:
+ return hwm_in_read(ddat, attr, val);
default:
return -EOPNOTSUPP;
}
@@ -76,6 +125,10 @@ static const struct hwmon_chip_info hwm_chip_info = {
static void
hwm_get_preregistration_info(struct drm_i915_private *i915)
{
+ struct i915_hwmon *hwmon = i915->hwmon;
+
+ /* Available for all Gen12+/dGfx */
+ hwmon->rg.gt_perf_status = GEN12_RPSTAT1;
}
void i915_hwmon_register(struct drm_i915_private *i915)
--
2.38.0
