arm, davinci: Add function lpsc_syncreset()

This patch adds a function lpsc_syncreset that allows setting a
lpsc module into Sync Reset state.

Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Cc: Heiko Schocher <hs@denx.de>
Cc: Paulraj Sandeep <s-paulraj@ti.com>
Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Acked-by: Heiko Schocher <hs@denx.de>
Tested-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>

arch/arm/cpu/arm926ejs/davinci/psc.c

@@ -46,7 +46,7 @@
  */
 
 /* Works on Always On power domain only (no PD argument) */
-void lpsc_on(unsigned int id)
+static void lpsc_transition(unsigned int id, unsigned int state)
 {
 	dv_reg_p mdstat, mdctl, ptstat, ptcmd;
 #ifdef CONFIG_SOC_DA8XX
@@ -83,10 +83,10 @@ void lpsc_on(unsigned int id)
 	while (readl(ptstat) & 0x01)
 		continue;
 
-	if ((readl(mdstat) & PSC_MDSTAT_STATE) == 0x03)
-		return; /* Already on and enabled */
+	if ((readl(mdstat) & PSC_MDSTAT_STATE) == state)
+		return; /* Already in that state */
 
-	writel(readl(mdctl) | 0x03, mdctl);
+	writel((readl(mdctl) & ~PSC_MDCTL_NEXT) | state, mdctl);
 
 	switch (id) {
 #ifdef CONFIG_SOC_DM644X
@@ -114,10 +114,20 @@ void lpsc_on(unsigned int id)
 
 	while (readl(ptstat) & 0x01)
 		continue;
-	while ((readl(mdstat) & PSC_MDSTAT_STATE) != 0x03)
+	while ((readl(mdstat) & PSC_MDSTAT_STATE) != state)
 		continue;
 }
 
+void lpsc_on(unsigned int id)
+{
+	lpsc_transition(id, 0x03);
+}
+
+void lpsc_syncreset(unsigned int id)
+{
+	lpsc_transition(id, 0x01);
+}
+
 /* Not all DaVinci chips have a DSP power domain. */
 #ifdef CONFIG_SOC_DM644X
 

arch/arm/include/asm/arch-davinci/hardware.h

@@ -292,6 +292,7 @@ typedef volatile unsigned int *	dv_reg_p;
 #endif /* CONFIG_SOC_DA8XX */
 
 void lpsc_on(unsigned int id);
+void lpsc_syncreset(unsigned int id);
 void dsp_on(void);
 
 void davinci_enable_uart0(void);
@@ -358,6 +359,7 @@ struct davinci_psc_regs {
 #endif /* CONFIG_SOC_DA8XX */
 
 #define PSC_MDSTAT_STATE		0x3f
+#define PSC_MDCTL_NEXT			0x07
 
 #ifndef CONFIG_SOC_DA8XX