drm/panthor: add sysfs knob for enabling job profiling

This commit introduces a DRM device sysfs attribute that lets UM control
the job accounting status in the device. The knob variable had been brought
in as part of a previous commit, but now we're able to fix it manually.

As sysfs files are part of a driver's uAPI, describe its legitimate input
values and output format in a documentation file.

Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240923230912.2207320-6-adrian.larumbe@collabora.com

1 files changed, 39 insertions, 0 deletions

diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index 388d1aea389d..f9b93f84d611 100644
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -1536,6 +1536,44 @@ 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_mask);
+}
+
+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);
+	u32 value;
+	int err;
+
+	err = kstrtou32(buf, 0, &value);
+	if (err)
+		return err;
+
+	if ((value & ~PANTHOR_DEVICE_PROFILING_ALL) != 0)
+		return -EINVAL;
+
+	ptdev->profile_mask = 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" },
@@ -1555,6 +1593,7 @@ static struct platform_driver panthor_driver = {
 		.name = "panthor",
 		.pm = pm_ptr(&panthor_pm_ops),
 		.of_match_table = dt_match,
+		.dev_groups = panthor_groups,
 	},
 };