Implement backlight control for amdgpu(4). This allows me to set

the backlight of my X395 using wsconsctl(8).  Unfortunately the
backlight hotkeys don't yet allow adjusting the brightness.

ok jsg@ kettenis@

1 files changed, 28 insertions, 2 deletions

diff --git a/sys/dev/pci/drm/amd/amdgpu/amdgpu_kms.c b/sys/dev/pci/drm/amd/amdgpu/amdgpu_kms.c
index 526306cf86f..595afdef9f1 100644
--- a/sys/dev/pci/drm/amd/amdgpu/amdgpu_kms.c
+++ b/sys/dev/pci/drm/amd/amdgpu/amdgpu_kms.c
@@ -1664,6 +1664,9 @@ int
 amdgpu_wsioctl(void *v, u_long cmd, caddr_t data, int flag, struct proc *p)
 {
 	struct rasops_info *ri = v;
+	struct amdgpu_device *adev = ri->ri_hw;
+	struct backlight_device *bd = adev->dm.backlight_dev;
+	struct wsdisplay_param *dp = (struct wsdisplay_param *)data;
 	struct wsdisplay_fbinfo *wdf;
 
 	switch (cmd) {
@@ -1677,9 +1680,32 @@ amdgpu_wsioctl(void *v, u_long cmd, caddr_t data, int flag, struct proc *p)
 		wdf->depth = ri->ri_depth;
 		wdf->cmsize = 0;
 		return 0;
-	default:
-		return -1;
+	case WSDISPLAYIO_GETPARAM:
+		if (bd == NULL)
+			return -1;
+
+		switch (dp->param) {
+		case WSDISPLAYIO_PARAM_BRIGHTNESS:
+			dp->min = 0;
+			dp->max = bd->props.max_brightness;
+			dp->curval = bd->ops->get_brightness(bd);
+			return (dp->max > dp->min) ? 0 : -1;
+		}
+		break;
+	case WSDISPLAYIO_SETPARAM:
+		if (bd == NULL || dp->curval > bd->props.max_brightness)
+			return -1;
+
+		switch (dp->param) {
+		case WSDISPLAYIO_PARAM_BRIGHTNESS:
+			bd->props.brightness = dp->curval;
+			backlight_update_status(bd);
+			return 0;
+		}
+		break;
 	}
+
+	return (-1);
 }
 
 paddr_t