drm/msm/edp: Drop regulator_set_voltage call

The eDP driver tries to set a fixed voltage for one of its regulators(vdda)
before enabling it. This shouldn't be done by the driver, the voltage
constraints should be specified on the regulator via DT and managed by
the regulator core. A driver should call regulator_set_voltage only if
it needs to change the voltage during runtime. Drop the
regulator_set_voltage call. Mention in a comment the voltage that the
regulator expects.

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/edp/edp_ctrl.c

@@ -21,8 +21,6 @@
 #include "edp.h"
 #include "edp.xml.h"
 
-#define VDDA_MIN_UV		1800000	/* uV units */
-#define VDDA_MAX_UV		1800000	/* uV units */
 #define VDDA_UA_ON_LOAD		100000	/* uA units */
 #define VDDA_UA_OFF_LOAD	100	/* uA units */
 
@@ -67,7 +65,7 @@ struct edp_ctrl {
 	void __iomem *base;
 
 	/* regulators */
-	struct regulator *vdda_vreg;
+	struct regulator *vdda_vreg;	/* 1.8 V */
 	struct regulator *lvl_vreg;
 
 	/* clocks */
@@ -329,12 +327,6 @@ static int edp_regulator_enable(struct edp_ctrl *ctrl)
 {
 	int ret;
 
-	ret = regulator_set_voltage(ctrl->vdda_vreg, VDDA_MIN_UV, VDDA_MAX_UV);
-	if (ret) {
-		pr_err("%s:vdda_vreg set_voltage failed, %d\n", __func__, ret);
-		goto vdda_set_fail;
-	}
-
 	ret = regulator_set_load(ctrl->vdda_vreg, VDDA_UA_ON_LOAD);
 	if (ret < 0) {
 		pr_err("%s: vdda_vreg set regulator mode failed.\n", __func__);