1 files changed, 100 insertions, 0 deletions
diff --git a/arch/powerpc/ddr-8xxx/util.c b/arch/powerpc/ddr-8xxx/util.c
new file mode 100644
index 0000000000..4525524926
--- /dev/null
+++ b/arch/powerpc/ddr-8xxx/util.c
@@ -0,0 +1,100 @@
+/*
+ * Copyright 2008-2012 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * Version 2 as published by the Free Software Foundation.
+ */
+
+#include <common.h>
+#include <asm/fsl_law.h>
+#include <linux/math64.h>
+#include <mach/clock.h>
+#include "ddr.h"
+
+#define ULL_2E12 2000000000000ULL
+#define UL_5POW12 244140625UL
+#define UL_2POW13 (1UL << 13)
+#define ULL_8FS 0xFFFFFFFFULL
+
+/*
+ * Round up mclk_ps to nearest 1 ps in memory controller code
+ * if the error is 0.5ps or more.
+ *
+ * If an imprecise data rate is too high due to rounding error
+ * propagation, compute a suitably rounded mclk_ps to compute
+ * a working memory controller configuration.
+ */
+uint32_t get_memory_clk_period_ps(void)
+{
+	uint32_t result, data_rate = fsl_get_ddr_freq(0);
+	/* Round to nearest 10ps, being careful about 64-bit multiply/divide */
+	uint64_t rem, mclk_ps = ULL_2E12;
+
+	/* Now perform the big divide, the result fits in 32-bits */
+	rem = do_div(mclk_ps, data_rate);
+	if (rem >= (data_rate >> 1))
+		result = mclk_ps + 1;
+	else
+		result = mclk_ps;
+
+	return result;
+}
+
+/* Convert picoseconds into DRAM clock cycles (rounding up if needed). */
+uint32_t picos_to_mclk(uint32_t picos)
+{
+	uint64_t clks, clks_rem;
+	uint32_t data_rate = fsl_get_ddr_freq(0);
+
+	if (!picos)
+		return 0;
+
+	/* First multiply the time by the data rate (32x32 => 64) */
+	clks = picos * (uint64_t)data_rate;
+	/*
+	 * Now divide by 5^12 and track the 32-bit remainder, then divide
+	 * by 2*(2^12) using shifts (and updating the remainder).
+	 */
+	clks_rem = do_div(clks, UL_5POW12);
+	clks_rem += (clks & (UL_2POW13 - 1)) * UL_5POW12;
+	clks >>= 13;
+
+	/* If we had a remainder greater than the 1ps error, then round up */
+	if (clks_rem > data_rate)
+		clks++;
+
+	if (clks > ULL_8FS)
+		clks = ULL_8FS;
+
+	return (uint32_t)clks;
+}
+
+uint32_t mclk_to_picos(unsigned int mclk)
+{
+	return get_memory_clk_period_ps() * mclk;
+}
+
+int fsl_ddr_set_lawbar(
+		const struct common_timing_params_s *params,
+		uint32_t law_memctl)
+{
+	uint64_t base = params->base_address;
+	uint64_t size = params->total_mem;
+
+	if (!params->ndimms_present)
+		goto out;
+
+	if (base >= MAX_MEM_MAPPED)
+		goto error;
+
+	if ((base + size) >= MAX_MEM_MAPPED)
+		size = MAX_MEM_MAPPED - base;
+
+	if (fsl_set_ddr_laws(base, size, law_memctl) < 0)
+		goto error;
+out:
+	return 0;
+error:
+	return 1;
+}