udlfb: add more comprehensive support for DPMS FB_BLANK_* modes
Fixes earlier problems where monitor would not return from blank
Test with any DisplayLink-based USB 2.0 graphics adapter
sudo nano /sys/class/graphics/fb?/blank
and write out single digit FB_BLANK_* code from include/linux/fb.h
Supports on (0), blank (1), suspend (2,3), powerdown (4)
Signed-off-by: Bernie Thompson <bernie@plugable.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
diff --git a/drivers/video/udlfb.c b/drivers/video/udlfb.c
index 087fc99..fecd2d3 100644
--- a/drivers/video/udlfb.c
+++ b/drivers/video/udlfb.c
@@ -94,17 +94,39 @@
}
/*
- * On/Off for driving the DisplayLink framebuffer to the display
- * 0x00 H and V sync on
- * 0x01 H and V sync off (screen blank but powered)
- * 0x07 DPMS powerdown (requires modeset to come back)
+ * Map FB_BLANK_* to DisplayLink register
+ * DLReg FB_BLANK_*
+ * ----- -----------------------------
+ * 0x00 FB_BLANK_UNBLANK (0)
+ * 0x01 FB_BLANK (1)
+ * 0x03 FB_BLANK_VSYNC_SUSPEND (2)
+ * 0x05 FB_BLANK_HSYNC_SUSPEND (3)
+ * 0x07 FB_BLANK_POWERDOWN (4) Note: requires modeset to come back
*/
-static char *dlfb_enable_hvsync(char *buf, bool enable)
+static char *dlfb_blanking(char *buf, int fb_blank)
{
- if (enable)
- return dlfb_set_register(buf, 0x1F, 0x00);
- else
- return dlfb_set_register(buf, 0x1F, 0x07);
+ u8 reg;
+
+ switch (fb_blank) {
+ case FB_BLANK_POWERDOWN:
+ reg = 0x07;
+ break;
+ case FB_BLANK_HSYNC_SUSPEND:
+ reg = 0x05;
+ break;
+ case FB_BLANK_VSYNC_SUSPEND:
+ reg = 0x03;
+ break;
+ case FB_BLANK_NORMAL:
+ reg = 0x01;
+ break;
+ default:
+ reg = 0x00;
+ }
+
+ buf = dlfb_set_register(buf, 0x1F, reg);
+
+ return buf;
}
static char *dlfb_set_color_depth(char *buf, u8 selection)
@@ -272,13 +294,15 @@
wrptr = dlfb_set_base8bpp(wrptr, dev->info->fix.smem_len);
wrptr = dlfb_set_vid_cmds(wrptr, var);
- wrptr = dlfb_enable_hvsync(wrptr, true);
+ wrptr = dlfb_blanking(wrptr, FB_BLANK_UNBLANK);
wrptr = dlfb_vidreg_unlock(wrptr);
writesize = wrptr - buf;
retval = dlfb_submit_urb(dev, urb, writesize);
+ dev->blank_mode = FB_BLANK_UNBLANK;
+
return retval;
}
@@ -1039,32 +1063,57 @@
return result;
}
+/* To fonzi the jukebox (e.g. make blanking changes take effect) */
+static char *dlfb_dummy_render(char *buf)
+{
+ *buf++ = 0xAF;
+ *buf++ = 0x6A; /* copy */
+ *buf++ = 0x00; /* from address*/
+ *buf++ = 0x00;
+ *buf++ = 0x00;
+ *buf++ = 0x01; /* one pixel */
+ *buf++ = 0x00; /* to address */
+ *buf++ = 0x00;
+ *buf++ = 0x00;
+ return buf;
+}
+
/*
* In order to come back from full DPMS off, we need to set the mode again
*/
static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
{
struct dlfb_data *dev = info->par;
+ char *bufptr;
+ struct urb *urb;
- if (blank_mode != FB_BLANK_UNBLANK) {
- char *bufptr;
- struct urb *urb;
+ pr_info("/dev/fb%d FB_BLANK mode %d --> %d\n",
+ info->node, dev->blank_mode, blank_mode);
- urb = dlfb_get_urb(dev);
- if (!urb)
- return 0;
+ if ((dev->blank_mode == FB_BLANK_POWERDOWN) &&
+ (blank_mode != FB_BLANK_POWERDOWN)) {
- bufptr = (char *) urb->transfer_buffer;
- bufptr = dlfb_vidreg_lock(bufptr);
- bufptr = dlfb_enable_hvsync(bufptr, false);
- bufptr = dlfb_vidreg_unlock(bufptr);
-
- dlfb_submit_urb(dev, urb, bufptr -
- (char *) urb->transfer_buffer);
- } else {
+ /* returning from powerdown requires a fresh modeset */
dlfb_set_video_mode(dev, &info->var);
}
+ urb = dlfb_get_urb(dev);
+ if (!urb)
+ return 0;
+
+ bufptr = (char *) urb->transfer_buffer;
+ bufptr = dlfb_vidreg_lock(bufptr);
+ bufptr = dlfb_blanking(bufptr, blank_mode);
+ bufptr = dlfb_vidreg_unlock(bufptr);
+
+ /* seems like a render op is needed to have blank change take effect */
+ bufptr = dlfb_dummy_render(bufptr);
+
+ dlfb_submit_urb(dev, urb, bufptr -
+ (char *) urb->transfer_buffer);
+
+ dev->blank_mode = blank_mode;
+
return 0;
}