arm, davinci: add workaround for not resetting DMA bus and VPSS modules

The Buffer Logic of VPSS is Not Reset by System Reset Pin, see
http://www.ti.com/lit/er/sprz316b/sprz316b.pdf chapter Advisory 1.2.1
on page 9. Add workaroundcode proposed in the errata.

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Sandeep Paulraj <s-paulraj@ti.com>
Cc: Tom Rini <tom.rini@gmail.com>

arch/arm/cpu/arm926ejs/davinci/dm365_lowlevel.c

@@ -254,7 +254,7 @@ int dm365_ddr_setup(void)
 	return 0;
 }
 
-void dm365_vpss_sync_reset(void)
+static void dm365_vpss_sync_reset(void)
 {
 	unsigned int PdNum = 0;
 
@@ -276,11 +276,52 @@ void dm365_vpss_sync_reset(void)
 		;
 }
 
-void dm365_por_reset(void)
+static void dm365_por_reset(void)
 {
+	struct davinci_timer *wdog =
+		(struct davinci_timer *)DAVINCI_WDOG_BASE;
+
 	if (readl(&dv_pll0_regs->rstype) &
-		(PLL_RSTYPE_POR | PLL_RSTYPE_XWRST))
+		(PLL_RSTYPE_POR | PLL_RSTYPE_XWRST)) {
 		dm365_vpss_sync_reset();
+
+		writel(DV_TMPBUF_VAL, TMPBUF);
+		setbits_le32(TMPSTATUS, FLAG_PORRST);
+		writel(DV_WDT_ENABLE_SYS_RESET, &wdog->na1);
+		writel(DV_WDT_TRIGGER_SYS_RESET, &wdog->na2);
+
+		while (1);
+	}
+}
+
+static void dm365_wdt_reset(void)
+{
+	struct davinci_timer *wdog =
+		(struct davinci_timer *)DAVINCI_WDOG_BASE;
+
+	if (readl(TMPBUF) != DV_TMPBUF_VAL) {
+		writel(DV_TMPBUF_VAL, TMPBUF);
+		setbits_le32(TMPSTATUS, FLAG_PORRST);
+		setbits_le32(TMPSTATUS, FLAG_FLGOFF);
+
+		dm365_waitloop(100);
+
+		dm365_vpss_sync_reset();
+
+		writel(DV_WDT_ENABLE_SYS_RESET, &wdog->na1);
+		writel(DV_WDT_TRIGGER_SYS_RESET, &wdog->na2);
+
+		while (1);
+	}
+}
+
+static void dm365_wdt_flag_on(void)
+{
+	/* VPSS_CLKMD 1:2 */
+	clrbits_le32(&dv_sys_module_regs->vpss_clkctl,
+		VPSS_CLK_CTL_VPSS_CLKMD);
+	writel(0, TMPBUF);
+	setbits_le32(TMPSTATUS, FLAG_FLGON);
 }
 
 void dm365_psc_init(void)
@@ -382,6 +423,9 @@ void dm36x_lowlevel_init(ulong bootflag)
 	writel(0xffffffff, &dv_aintc_regs->irq0);
 	writel(0xffffffff, &dv_aintc_regs->irq1);
 
+	dm365_por_reset();
+	dm365_wdt_reset();
+
 	/* System PSC setup - enable all */
 	dm365_psc_init();
 
@@ -418,6 +462,8 @@ void dm36x_lowlevel_init(ulong bootflag)
 	puts("emif init\n");
 	dm365_emif_init();
 
+	dm365_wdt_flag_on();
+
 #if defined(CONFIG_POST)
 	/*
 	 * Do memory tests, calls arch_memory_failure_handle()

arch/arm/include/asm/arch-davinci/dm365_lowlevel.h

@@ -32,7 +32,6 @@ void dm365_waitloop(unsigned long loopcnt);
 int dm365_pll1_init(unsigned long pllmult, unsigned long prediv);
 int dm365_pll2_init(unsigned long pllm, unsigned long prediv);
 int dm365_ddr_setup(void);
-void dm365_por_reset(void);
 void dm365_psc_init(void);
 void dm365_pinmux_ctl(unsigned long offset, unsigned long mask,
 	unsigned long value);

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

@@ -587,6 +587,15 @@ static inline int get_async3_src(void)
 #include <asm/arch/psc_defs.h>
 #include <asm/arch/syscfg_defs.h>
 #include <asm/arch/timer_defs.h>
+
+#define TMPBUF			0x00017ff8
+#define TMPSTATUS		0x00017ff0
+#define DV_TMPBUF_VAL		0x591b3ed7
+#define FLAG_PORRST		0x00000001
+#define FLAG_WDTRST		0x00000002
+#define FLAG_FLGON		0x00000004
+#define FLAG_FLGOFF		0x00000010
+
 #endif
 
 struct davinci_rtc {

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

@@ -37,6 +37,9 @@ struct davinci_timer {
 	u_int32_t	wdtcr;
 };
 
+#define DV_WDT_ENABLE_SYS_RESET		0x00020000
+#define DV_WDT_TRIGGER_SYS_RESET	0x00020002
+
 #ifdef CONFIG_HW_WATCHDOG
 void davinci_hw_watchdog_enable(void);
 void davinci_hw_watchdog_reset(void);