+#ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
+/*
+ * The realtime counter also called master counter, is a free-running
+ * counter, which is related to real time. It produces the count used
+ * by the CPU local timer peripherals in the MPU cluster. The timer counts
+ * at a rate of 6.144 MHz. Because the device operates on different clocks
+ * in different power modes, the master counter shifts operation between
+ * clocks, adjusting the increment per clock in hardware accordingly to
+ * maintain a constant count rate.
+ */
+static void __init realtime_counter_init(void)
+{
+ void __iomem *base;
+ static struct clk *sys_clk;
+ unsigned long rate;
+ unsigned int reg, num, den;
+
+ base = ioremap(REALTIME_COUNTER_BASE, SZ_32);
+ if (!base) {
+ pr_err("%s: ioremap failed\n", __func__);
+ return;
+ }
+ sys_clk = clk_get(NULL, "sys_clkin_ck");
+ if (!sys_clk) {
+ pr_err("%s: failed to get system clock handle\n", __func__);
+ iounmap(base);
+ return;
+ }
+
+ rate = clk_get_rate(sys_clk);
+ /* Numerator/denumerator values refer TRM Realtime Counter section */
+ switch (rate) {
+ case 1200000:
+ num = 64;
+ den = 125;
+ break;
+ case 1300000:
+ num = 768;
+ den = 1625;
+ break;
+ case 19200000:
+ num = 8;
+ den = 25;
+ break;
+ case 2600000:
+ num = 384;
+ den = 1625;
+ break;
+ case 2700000:
+ num = 256;
+ den = 1125;
+ break;
+ case 38400000:
+ default:
+ /* Program it for 38.4 MHz */
+ num = 4;
+ den = 25;
+ break;
+ }
+
+ /* Program numerator and denumerator registers */
+ reg = __raw_readl(base + INCREMENTER_NUMERATOR_OFFSET) &
+ NUMERATOR_DENUMERATOR_MASK;
+ reg |= num;
+ __raw_writel(reg, base + INCREMENTER_NUMERATOR_OFFSET);
+
+ reg = __raw_readl(base + INCREMENTER_NUMERATOR_OFFSET) &
+ NUMERATOR_DENUMERATOR_MASK;
+ reg |= den;
+ __raw_writel(reg, base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET);
+
+ iounmap(base);
+}
+#else
+static inline void __init realtime_counter_init(void)
+{}
+#endif
+