OMAP3+: VP: combine setting init voltage into common function

combine VPCONFIG init voltage setup into common function and use from
both vp_enable and from vp_forceupdate_scale().

NOTE: this patch changes the sequence of when the initVDD bit is
cleared.  The bit is now cleared immediately after it was written.
Since only the rising edge of this bit has any affect according to the
TRM, the exact timing of clearing of this bit should not have any
effect.
Signed-off-by: Kevin Hilman <khilman@ti.com>

arch/arm/mach-omap2/vp.c

@@ -9,31 +9,18 @@
 #include "prm-regbits-44xx.h"
 #include "prm44xx.h"
 
-static void vp_latch_vsel(struct voltagedomain *voltdm)
+static u32 _vp_set_init_voltage(struct voltagedomain *voltdm, u32 volt)
 {
 	struct omap_vp_instance *vp = voltdm->vp;
 	u32 vpconfig;
-	unsigned long uvdc;
 	char vsel;
 
-	uvdc = omap_voltage_get_nom_volt(voltdm);
-	if (!uvdc) {
-		pr_warning("%s: unable to find current voltage for vdd_%s\n",
-			__func__, voltdm->name);
-		return;
-	}
-
-	if (!voltdm->pmic || !voltdm->pmic->uv_to_vsel) {
-		pr_warning("%s: PMIC function to convert voltage in uV to"
-			" vsel not registered\n", __func__);
-		return;
-	}
-
-	vsel = voltdm->pmic->uv_to_vsel(uvdc);
+	vsel = voltdm->pmic->uv_to_vsel(volt);
 
 	vpconfig = voltdm->read(vp->vpconfig);
 	vpconfig &= ~(vp->common->vpconfig_initvoltage_mask |
-			vp->common->vpconfig_initvdd);
+		      vp->common->vpconfig_forceupdate |
+		      vp->common->vpconfig_initvdd);
 	vpconfig |= vsel << __ffs(vp->common->vpconfig_initvoltage_mask);
 	voltdm->write(vpconfig, vp->vpconfig);
 
@@ -43,6 +30,8 @@ static void vp_latch_vsel(struct voltagedomain *voltdm)
 
 	/* Clear initVDD copy trigger bit */
 	voltdm->write(vpconfig, vp->vpconfig);
+
+	return vpconfig;
 }
 
 /* Generic voltage init functions */
@@ -149,22 +138,11 @@ int omap_vp_forceupdate_scale(struct voltagedomain *voltdm,
 		return -ETIMEDOUT;
 	}
 
-	/* Configure for VP-Force Update */
-	vpconfig = voltdm->read(vp->vpconfig);
-	vpconfig &= ~(vp->common->vpconfig_initvdd |
-			vp->common->vpconfig_forceupdate |
-			vp->common->vpconfig_initvoltage_mask);
-	vpconfig |= ((target_vsel <<
-		      __ffs(vp->common->vpconfig_initvoltage_mask)));
-	voltdm->write(vpconfig, vp->vpconfig);
-
-	/* Trigger initVDD value copy to voltage processor */
-	vpconfig |= vp->common->vpconfig_initvdd;
-	voltdm->write(vpconfig, vp->vpconfig);
+	vpconfig = _vp_set_init_voltage(voltdm, target_volt);
 
 	/* Force update of voltage */
-	vpconfig |= vp->common->vpconfig_forceupdate;
-	voltdm->write(vpconfig, vp->vpconfig);
+	voltdm->write(vpconfig | vp->common->vpconfig_forceupdate,
+		      voltdm->vp->vpconfig);
 
 	/*
 	 * Wait for TransactionDone. Typical latency is <200us.
@@ -197,12 +175,7 @@ int omap_vp_forceupdate_scale(struct voltagedomain *voltdm,
 			"to clear the TRANXDONE status\n",
 			__func__, voltdm->name);
 
-	vpconfig = voltdm->read(vp->vpconfig);
-	/* Clear initVDD copy trigger bit */
-	vpconfig &= ~vp->common->vpconfig_initvdd;
-	voltdm->write(vpconfig, vp->vpconfig);
 	/* Clear force bit */
-	vpconfig &= ~vp->common->vpconfig_forceupdate;
 	voltdm->write(vpconfig, vp->vpconfig);
 
 	return 0;
@@ -218,7 +191,7 @@ int omap_vp_forceupdate_scale(struct voltagedomain *voltdm,
 void omap_vp_enable(struct voltagedomain *voltdm)
 {
 	struct omap_vp_instance *vp;
-	u32 vpconfig;
+	u32 vpconfig, volt;
 
 	if (!voltdm || IS_ERR(voltdm)) {
 		pr_warning("%s: VDD specified does not exist!\n", __func__);
@@ -236,12 +209,19 @@ void omap_vp_enable(struct voltagedomain *voltdm)
 	if (vp->enabled)
 		return;
 
-	vp_latch_vsel(voltdm);
+	volt = voltdm_get_voltage(voltdm);
+	if (!volt) {
+		pr_warning("%s: unable to find current voltage for %s\n",
+			   __func__, voltdm->name);
+		return;
+	}
+
+	vpconfig = _vp_set_init_voltage(voltdm, volt);
 
 	/* Enable VP */
-	vpconfig = voltdm->read(vp->vpconfig);
 	vpconfig |= vp->common->vpconfig_vpenable;
 	voltdm->write(vpconfig, vp->vpconfig);
+
 	vp->enabled = true;
 }