ARM: OMAP2+: Configure voltage controller for retention

Similar to existing omap3_vc_set_pmic_signaling(), let's add omap4
specific omap4_vc_set_pmic_signaling(). This allows the configured
devices to enable voltage controller for retention later on during
init.

Cc: Merlijn Wajer <merlijn@wizzup.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/vc.c

@@ -36,15 +36,21 @@
 #define OMAP4430_AUTO_CTRL_VDD_CORE(x)		((x) << 0)
 #define OMAP4430_AUTO_CTRL_VDD_RET		2
 
-#define OMAP4_VDD_DEFAULT_VAL	\
+#define OMAP4430_VDD_I2C_DISABLE_MASK	\
 	(OMAP4430_VDD_IVA_I2C_DISABLE | \
-	 OMAP4430_VDD_MPU_I2C_DISABLE |	 \
-	 OMAP4430_VDD_CORE_I2C_DISABLE | \
+	 OMAP4430_VDD_MPU_I2C_DISABLE | \
+	 OMAP4430_VDD_CORE_I2C_DISABLE)
+
+#define OMAP4_VDD_DEFAULT_VAL	\
+	(OMAP4430_VDD_I2C_DISABLE_MASK | \
 	 OMAP4430_VDD_IVA_PRESENCE | OMAP4430_VDD_MPU_PRESENCE | \
 	 OMAP4430_AUTO_CTRL_VDD_IVA(OMAP4430_AUTO_CTRL_VDD_RET) | \
 	 OMAP4430_AUTO_CTRL_VDD_MPU(OMAP4430_AUTO_CTRL_VDD_RET) | \
 	 OMAP4430_AUTO_CTRL_VDD_CORE(OMAP4430_AUTO_CTRL_VDD_RET))
 
+#define OMAP4_VDD_RET_VAL	\
+	(OMAP4_VDD_DEFAULT_VAL & ~OMAP4430_VDD_I2C_DISABLE_MASK)
+
 /**
  * struct omap_vc_channel_cfg - describe the cfg_channel bitfield
  * @sa: bit for slave address
@@ -299,6 +305,26 @@ void omap3_vc_set_pmic_signaling(int core_next_state)
 	}
 }
 
+void omap4_vc_set_pmic_signaling(int core_next_state)
+{
+	struct voltagedomain *vd = vc.vd;
+	u32 val;
+
+	if (!vd)
+		return;
+
+	switch (core_next_state) {
+	case PWRDM_POWER_RET:
+		val = OMAP4_VDD_RET_VAL;
+		break;
+	default:
+		val = OMAP4_VDD_DEFAULT_VAL;
+		break;
+	}
+
+	vd->write(val, OMAP4_PRM_VOLTCTRL_OFFSET);
+}
+
 /*
  * Configure signal polarity for sys_clkreq and sys_off_mode pins
  * as the default values are wrong and can cause the system to hang

arch/arm/mach-omap2/vc.h

@@ -117,7 +117,7 @@ extern struct omap_vc_param omap4_iva_vc_data;
 extern struct omap_vc_param omap4_core_vc_data;
 
 void omap3_vc_set_pmic_signaling(int core_next_state);
-
+void omap4_vc_set_pmic_signaling(int core_next_state);
 
 void omap_vc_init_channel(struct voltagedomain *voltdm);
 int omap_vc_pre_scale(struct voltagedomain *voltdm,