GK SDK 源码库: XMIPCLinuxV100R005C00SPC030 (kernel/tools/open_source excluded)

mcu/riscv/drivers/timer/Makefile

@@ -0,0 +1 @@
+SRCS-y += timer.c

mcu/riscv/drivers/timer/timer.c

@@ -0,0 +1,78 @@
+
+#include <common.h>
+#include <timer.h>
+
+#define TIMER_LOAD      0
+#define TIMER_VALUE     0x4
+#define TIMER_CONTROL   0x8
+
+#define CFG_TIMER_CTRL  0xc0
+
+#define TIMER_FEQ       24000000
+
+#define TIMER_DIV       1
+
+#define TIMER_NOR_DIVIDER_US   (TIMER_FEQ / TIMER_DIV / 1000000)
+
+#define UDELAY_US_MAX   (61 * 1000 * 1000UL)
+
+#define REG_TIMER_BASE    TIMER3_REG_BASE
+
+#define timer_reg_get(offset)      readl(REG_TIMER_BASE + (offset))
+#define timer_reg_set(offset, val) writel(val, REG_TIMER_BASE + (offset))
+
+static u8 g_timer_init = 0;
+
+ulong timer_get_val(void)
+{
+	return ~1UL - timer_reg_get(TIMER_VALUE);
+}
+
+void udelay(ulong us)
+{
+	ulong cur, start, end;
+	ulong count;
+
+	if (us == 0)
+		return;
+
+	assert(g_timer_init == 1);
+
+	start = timer_get_val();
+
+	if (us >= UDELAY_US_MAX) {
+		puts("WARNING: long udelay, use ");
+		putdec(UDELAY_US_MAX);
+		puts("us instead!\n");
+		count = UDELAY_US_MAX * TIMER_NOR_DIVIDER_US;
+	} else
+		count = us * TIMER_NOR_DIVIDER_US;
+
+	end = start + count;
+
+	while (1) {
+		cur = timer_get_val();
+		if ((end >= start && cur >= end ) ||
+			(end < start && cur >= end && cur < start))
+			break;
+	}
+}
+
+void mdelay(u32 msec)
+{
+	assert(g_timer_init == 1);
+
+	udelay(msec * 1000);
+}
+
+void timer_init(void)
+{
+        timer_reg_set(TIMER_CONTROL, 0);
+	timer_reg_set(TIMER_LOAD, 0xffffffff);
+        timer_reg_set(TIMER_CONTROL, CFG_TIMER_CTRL);
+
+	g_timer_init = 1;
+}
+
+
+