[PATCH v3 4/7] drm/panthor: add sysfs knob for enabling job profiling

["Adrián Larumbe" <adrian.larumbe@collabora.com>]

Just like it is already present in Panfrost, this commit introduces a DRM
device sysfs file that lets UM control the job accounting status in the
device.

The present commit only brings in the sysfs knob and also hides the cycles
and engine fdinfo tags when it's disabled, but leveraging it for job
accounting will be the matter of a later commit.

Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
---
 drivers/gpu/drm/panthor/panthor_device.h |  1 +
 drivers/gpu/drm/panthor/panthor_drv.c    | 46 +++++++++++++++++++++---
 2 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
index 8a0260a7b90a..c3ec1e31f8b7 100644
--- a/drivers/gpu/drm/panthor/panthor_device.h
+++ b/drivers/gpu/drm/panthor/panthor_device.h
@@ -163,6 +163,7 @@ struct panthor_device {
 		struct page *dummy_latest_flush;
 	} pm;
 
+	bool profile_mode;
 	unsigned long current_frequency;
 	unsigned long fast_rate;
 };
diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index 6d25385e02a1..a2876310856f 100644
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -1360,12 +1360,14 @@ static void panthor_gpu_show_fdinfo(struct panthor_device *ptdev,
 				    struct panthor_file *pfile,
 				    struct drm_printer *p)
 {
+	if (ptdev->profile_mode) {
 #ifdef CONFIG_ARM_ARCH_TIMER
-	drm_printf(p, "drm-engine-panthor:\t%llu ns\n",
-		   DIV_ROUND_UP_ULL((pfile->stats.time * NSEC_PER_SEC),
-				    arch_timer_get_cntfrq()));
+		drm_printf(p, "drm-engine-panthor:\t%llu ns\n",
+			   DIV_ROUND_UP_ULL((pfile->stats.time * NSEC_PER_SEC),
+					    arch_timer_get_cntfrq()));
 #endif
-	drm_printf(p, "drm-cycles-panthor:\t%llu\n", pfile->stats.cycles);
+		drm_printf(p, "drm-cycles-panthor:\t%llu\n", pfile->stats.cycles);
+	}
 	drm_printf(p, "drm-maxfreq-panthor:\t%lu Hz\n", ptdev->fast_rate);
 	drm_printf(p, "drm-curfreq-panthor:\t%lu Hz\n", ptdev->current_frequency);
 }
@@ -1446,6 +1448,41 @@ static void panthor_remove(struct platform_device *pdev)
 	panthor_device_unplug(ptdev);
 }
 
+static ssize_t profiling_show(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	struct panthor_device *ptdev = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", ptdev->profile_mode);
+}
+
+static ssize_t profiling_store(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t len)
+{
+	struct panthor_device *ptdev = dev_get_drvdata(dev);
+	bool value;
+	int err;
+
+	err = kstrtobool(buf, &value);
+	if (err)
+		return err;
+
+	ptdev->profile_mode = value;
+
+	return len;
+}
+
+static DEVICE_ATTR_RW(profiling);
+
+static struct attribute *panthor_attrs[] = {
+	&dev_attr_profiling.attr,
+	NULL,
+};
+
+ATTRIBUTE_GROUPS(panthor);
+
 static const struct of_device_id dt_match[] = {
 	{ .compatible = "rockchip,rk3588-mali" },
 	{ .compatible = "arm,mali-valhall-csf" },
@@ -1465,6 +1502,7 @@ static struct platform_driver panthor_driver = {
 		.name = "panthor",
 		.pm = pm_ptr(&panthor_pm_ops),
 		.of_match_table = dt_match,
+		.dev_groups = panthor_groups,
 	},
 };
 
-- 
2.45.1