imx: system counter driver for imx7d and mx6ul
Add system counter driver for imx7d and mx6ul
imx7 and imx6ul supports system counter timer as well as
GPT timer (arch/arm/imx-common/timer.c); The default for
imx7 is systemcounter timer.
Signed-off-by: Ye.Li <B37916@freescale.com>
Signed-off-by: Adrian Alonso <aalonso@freescale.com>
diff --git a/arch/arm/imx-common/syscounter.c b/arch/arm/imx-common/syscounter.c
new file mode 100644
index 0000000..e00fef2
--- /dev/null
+++ b/arch/arm/imx-common/syscounter.c
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2015 Freescale Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * The file use ls102xa/timer.c as a reference.
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <div64.h>
+#include <asm/arch/imx-regs.h>
+#include <asm/arch/sys_proto.h>
+#include <asm/imx-common/syscounter.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/*
+ * This function is intended for SHORT delays only.
+ * It will overflow at around 10 seconds @ 400MHz,
+ * or 20 seconds @ 200MHz.
+ */
+unsigned long usec2ticks(unsigned long usec)
+{
+ ulong ticks;
+
+ if (usec < 1000)
+ ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
+ else
+ ticks = ((usec / 10) * (get_tbclk() / 100000));
+
+ return ticks;
+}
+
+static inline unsigned long long tick_to_time(unsigned long long tick)
+{
+ unsigned long freq;
+
+ asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
+
+ tick *= CONFIG_SYS_HZ;
+ do_div(tick, freq);
+
+ return tick;
+}
+
+static inline unsigned long long us_to_tick(unsigned long long usec)
+{
+ unsigned long freq;
+
+ asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
+
+ usec = usec * freq + 999999;
+ do_div(usec, 1000000);
+
+ return usec;
+}
+
+int timer_init(void)
+{
+ struct sctr_regs *sctr = (struct sctr_regs *)SCTR_BASE_ADDR;
+ unsigned long val, freq;
+
+ freq = CONFIG_SC_TIMER_CLK;
+ asm("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq));
+
+ writel(freq, &sctr->cntfid0);
+
+ /* Enable system counter */
+ val = readl(&sctr->cntcr);
+ val &= ~(SC_CNTCR_FREQ0 | SC_CNTCR_FREQ1);
+ val |= SC_CNTCR_FREQ0 | SC_CNTCR_ENABLE | SC_CNTCR_HDBG;
+ writel(val, &sctr->cntcr);
+
+ gd->arch.tbl = 0;
+ gd->arch.tbu = 0;
+
+ return 0;
+}
+
+unsigned long long get_ticks(void)
+{
+ unsigned long long now;
+
+ asm("mrrc p15, 0, %Q0, %R0, c14" : "=r" (now));
+
+ gd->arch.tbl = (unsigned long)(now & 0xffffffff);
+ gd->arch.tbu = (unsigned long)(now >> 32);
+
+ return now;
+}
+
+ulong get_timer_masked(void)
+{
+ return tick_to_time(get_ticks());
+}
+
+ulong get_timer(ulong base)
+{
+ return get_timer_masked() - base;
+}
+
+void __udelay(unsigned long usec)
+{
+ unsigned long long tmp;
+ ulong tmo;
+
+ tmo = us_to_tick(usec);
+ tmp = get_ticks() + tmo; /* get current timestamp */
+
+ while (get_ticks() < tmp) /* loop till event */
+ /*NOP*/;
+}
+
+/*
+ * This function is derived from PowerPC code (timebase clock frequency).
+ * On ARM it returns the number of timer ticks per second.
+ */
+ulong get_tbclk(void)
+{
+ unsigned long freq;
+
+ asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
+
+ return freq;
+}