A27系列优化I2C/RTC处理，新增版本A270Y

A27-STEPLDR/Src/wdt.c

@@ -0,0 +1,142 @@
+#include "amt630h.h"
+#include "uart.h"
+
+#define WTCON		0x00
+#define WTPSR		0x04
+#define WTCNT		0x08
+#define WTCLRINT	0x10
+#define WTRCR		0x14
+
+#define WTCNT_MAXCNT	0xffff
+#define WTCON_MAXDIV	0x80
+
+#define WTCON_ENABLE	(1 << 0)
+#define WTCON_RSTEN		(1 << 1)
+#define WTCON_INTEN		(1 << 2)
+
+#define WTCON_DIV16		(0 << 4)
+#define WTCON_DIV32		(1 << 4)
+#define WTCON_DIV64		(2 << 4)
+#define WTCON_DIV128	(3 << 4)
+#define WTCON_DIVMASK	(0x3 << 4)
+
+#define WTCON_PRESCALE_MAX	0x10000
+
+#define WATCHDOG_DEFAULT_TIME	(3)
+
+#define CLK_APB_FREQ	198000000
+
+static int wdt_timeout = WATCHDOG_DEFAULT_TIME;
+static int soft_noboot = 0;		/* 1: not reboot when watchdog timer expired */
+static int wdt_count;
+
+static inline unsigned int wdt_max_timeout()
+{
+	unsigned long freq = CLK_APB_FREQ;
+
+	return WTCNT_MAXCNT / (freq / WTCON_PRESCALE_MAX
+				       / WTCON_MAXDIV);
+}
+
+int wdt_set_heartbeat(unsigned int timeout)
+{
+	unsigned long freq = CLK_APB_FREQ;
+	unsigned int count;
+	unsigned int divisor = 1;
+
+	if (timeout < 1 || timeout > wdt_max_timeout())
+		return -EINVAL;
+
+	freq = DIV_ROUND_UP(freq, 128);
+	count = timeout * freq;
+
+	/* TRACE_DEBUG("Heartbeat: count=%d, timeout=%d, freq=%lu\n",
+		count, timeout, freq); */
+
+	/* if the count is bigger than the watchdog register,
+	   then work out what we need to do (and if) we can
+	   actually make this value
+	*/
+
+	if (count >= 0x10000) {
+		divisor = DIV_ROUND_UP(count, 0xffff);
+
+		if (divisor > WTCON_PRESCALE_MAX) {
+			SendUartString("timeout too big\n");
+			return -EINVAL;
+		}
+	}
+
+	/* TRACE_DEBUG("Heartbeat: timeout=%d, divisor=%d, count=%d (%08x)\n",
+		timeout, divisor, count, DIV_ROUND_UP(count, divisor)); */
+
+	count = DIV_ROUND_UP(count, divisor);
+	wdt_count = count;
+
+	/* update the pre-scaler */
+	writel(divisor - 1, WDT_BASE + WTPSR);
+
+	writel(count, WDT_BASE + WTCNT);
+
+	wdt_timeout = timeout;
+
+	return 0;
+}
+
+void wdt_stop(void)
+{
+	unsigned long wtcon;
+
+	wtcon = readl(WDT_BASE + WTCON);
+	wtcon &= ~(WTCON_ENABLE | WTCON_RSTEN);
+	writel(wtcon, WDT_BASE + WTCON);
+}
+
+void wdt_start(void)
+{
+	unsigned long wtcon;
+
+	wdt_stop();
+
+	wtcon = readl(WDT_BASE + WTCON);
+	wtcon &= ~WTCON_DIVMASK;
+	wtcon |= WTCON_ENABLE | WTCON_DIV128;
+	if (soft_noboot) {
+		wtcon |= WTCON_INTEN;
+		wtcon &= ~WTCON_RSTEN;
+	} else {
+		wtcon &= ~WTCON_INTEN;
+		wtcon |= WTCON_RSTEN;
+	}
+
+	/* TRACE_DEBUG("Starting watchdog: count=0x%08x, wtcon=%08lx\n",
+		wdt_count, wtcon); */
+
+	writel(wdt_count, WDT_BASE + WTCNT);
+	writel(wtcon, WDT_BASE + WTCON);
+}
+
+int wdt_init(void)
+{
+	int ret;
+
+	wdt_stop();
+
+	ret = wdt_set_heartbeat(wdt_timeout);
+	if (ret) {
+		SendUartString("failed to set timeout value\n");
+	}
+
+	wdt_start();
+
+	return 0;
+}
+
+void wdt_cpu_reboot(void)
+{
+	SendUartString("cpu reboot...\n");
+	soft_noboot = 0;
+	wdt_count = 300;
+	wdt_start();
+	while(1);
+}