1 files changed, 78 insertions, 0 deletions
diff --git a/arch/blackfin/include/asm/clock.h b/arch/blackfin/include/asm/clock.h
new file mode 100644
index 00000000000..f1fcd404993
--- /dev/null
+++ b/arch/blackfin/include/asm/clock.h
@@ -0,0 +1,78 @@
+
+/*
+ * Copyright (C) 2012 Analog Devices Inc.
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef __CLOCK_H__
+#define __CLOCK_H__
+
+#include <asm/blackfin.h>
+#ifdef PLL_CTL
+#include <asm/mach-common/bits/pll.h>
+# define pll_is_bypassed() (bfin_read_PLL_CTL() & BYPASS)
+#else
+#include <asm/mach-common/bits/cgu.h>
+# define pll_is_bypassed() (bfin_read_CGU_STAT() & PLLBP)
+# define bfin_read_PLL_CTL() bfin_read_CGU_CTL()
+# define bfin_read_PLL_DIV() bfin_read_CGU_DIV()
+# define SSEL SYSSEL
+# define SSEL_P SYSSEL_P
+#endif
+
+__attribute__((always_inline))
+static inline uint32_t early_division(uint32_t dividend, uint32_t divisor)
+{
+	uint32_t quotient;
+	uint32_t i, j;
+
+	for (quotient = 1, i = 1; dividend > divisor; ++i) {
+		j = divisor << i;
+		if (j > dividend || (j & 0x80000000)) {
+			--i;
+			quotient += (1 << i);
+			dividend -= (divisor << i);
+			i = 0;
+		}
+	}
+
+	return quotient;
+}
+
+__attribute__((always_inline))
+static inline uint32_t early_get_uart_clk(void)
+{
+	uint32_t msel, pll_ctl, vco;
+	uint32_t div, ssel, sclk, uclk;
+
+	pll_ctl = bfin_read_PLL_CTL();
+	msel = (pll_ctl & MSEL) >> MSEL_P;
+	if (msel == 0)
+		msel = (MSEL >> MSEL_P) + 1;
+
+	vco = (CONFIG_CLKIN_HZ >> (pll_ctl & DF)) * msel;
+	sclk = vco;
+	if (!pll_is_bypassed()) {
+		div = bfin_read_PLL_DIV();
+		ssel = (div & SSEL) >> SSEL_P;
+#if CONFIG_BFIN_BOOT_MODE == BFIN_BOOT_BYPASS
+		sclk = vco/ssel;
+#else
+		sclk = early_division(vco, ssel);
+#endif
+	}
+	uclk = sclk;
+#ifdef CGU_DIV
+	ssel = (div & S0SEL) >> S0SEL_P;
+	uclk = early_division(sclk, ssel);
+#endif
+	return uclk;
+}
+
+#ifdef CGU_DIV
+# define get_uart_clk get_sclk0
+#else
+# define get_uart_clk get_sclk
+#endif
+
+#endif