drm/bridge/synopsys: dsi: explicitly request exclusive reset control

Based on patch "Convert drivers to explicit reset API" from Philipp Zabel

Commit a53e35db ("reset: Ensure drivers are explicit when requesting
reset lines") started to transition the reset control request API calls
to explicitly state whether the driver needs exclusive or shared reset
control behavior. Convert all drivers requesting exclusive resets to the
explicit API call so the temporary transition helpers can be removed.

No functional changes.

Cc: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Philippe CORNU <philippe.cornu@st.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1501593788-21036-4-git-send-email-philippe.cornu@st.com

drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c

@@ -885,15 +885,14 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
 	 * Note that the reset was not defined in the initial device tree, so
 	 * we have to be prepared for it not being found.
 	 */
-	apb_rst = devm_reset_control_get(dev, "apb");
+	apb_rst = devm_reset_control_get_optional_exclusive(dev, "apb");
 	if (IS_ERR(apb_rst)) {
 		ret = PTR_ERR(apb_rst);
-		if (ret == -ENOENT) {
-			apb_rst = NULL;
-		} else {
+
+		if (ret != -EPROBE_DEFER)
 			dev_err(dev, "Unable to get reset control: %d\n", ret);
-			return ERR_PTR(ret);
-		}
+
+		return ERR_PTR(ret);
 	}
 
 	if (apb_rst) {