panel-sitronix-st7701: Fix panel prepare over SPI

A DSI write is issued in st7701_prepare even when the probed panel
runs on SPI. In practice, this results in a panic with the
vc4-kms-dpi-hyperpixel2r overlay active.

Perform the equivalent write over SPI in this case.

Signed-off-by: Jack Andersen <jackoalan@gmail.com>

diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7701.c b/drivers/gpu/drm/panel/panel-sitronix-st7701.c
index 16e8b5e..b226d8a 100644 (file)
--- a/drivers/gpu/drm/panel/panel-sitronix-st7701.c
+++ b/drivers/gpu/drm/panel/panel-sitronix-st7701.c
@@ -605,7 +605,15 @@ static int st7701_prepare(struct drm_panel *panel)
                st7701->desc->gip_sequence(st7701);
 
        /* Disable Command2 */
-       st7701_switch_cmd_bkx(st7701, false, 0);
+       switch (st7701->desc->interface) {
+       case ST7701_CTRL_DSI:
+               st7701_switch_cmd_bkx(st7701, false, 0);
+               break;
+       case ST7701_CTRL_SPI:
+               ST7701_SPI(st7701, DSI_CMD2BKX_SEL,
+                          0x177, 0x101, 0x100, 0x100, SPI_CMD2BKX_SEL_NONE);
+               break;
+       }
 
        return 0;
 }