mips: ath79: Add AR934x support

Add support for the Atheros AR934x WiSoCs. This patchs adds complete
system init, including PLL and DRAM init, both of which happen from
full C environment, since the AR934x has proper SRAM.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Wills Wang <wills.wang@live.com>

4 files changed, 514 insertions, 0 deletions

diff --git a/arch/mips/mach-ath79/ar934x/Makefile b/arch/mips/mach-ath79/ar934x/Makefile
new file mode 100644
index 0000000000..348c65b253
--- /dev/null
+++ b/arch/mips/mach-ath79/ar934x/Makefile
@@ -0,0 +1,7 @@
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-y += cpu.o
+obj-y += clk.o
+obj-y += ddr.o
diff --git a/arch/mips/mach-ath79/ar934x/clk.c b/arch/mips/mach-ath79/ar934x/clk.c
new file mode 100644
index 0000000000..9c65184e7a
--- /dev/null
+++ b/arch/mips/mach-ath79/ar934x/clk.c
@@ -0,0 +1,334 @@
+/*
+ * Copyright (C) 2016 Marek Vasut <marex@denx.de>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/addrspace.h>
+#include <asm/types.h>
+#include <mach/ar71xx_regs.h>
+#include <mach/reset.h>
+#include <wait_bit.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/*
+ * The math for calculating PLL:
+ *                                       NFRAC * 2^8
+ *                               NINT + -------------
+ *                XTAL [MHz]              2^(18 - 1)
+ *   PLL [MHz] = ------------ * ----------------------
+ *                  REFDIV              2^OUTDIV
+ *
+ * Unfortunatelly, there is no way to reliably compute the variables.
+ * The vendor U-Boot port contains macros for various combinations of
+ * CPU PLL / DDR PLL / AHB bus speed and there is no obvious pattern
+ * in those numbers.
+ */
+struct ar934x_pll_config {
+	u8	range;
+	u8	refdiv;
+	u8	outdiv;
+	/* Index 0 is for XTAL=25MHz , Index 1 is for XTAL=40MHz */
+	u8	nint[2];
+};
+
+struct ar934x_clock_config {
+	u16				cpu_freq;
+	u16				ddr_freq;
+	u16				ahb_freq;
+
+	struct ar934x_pll_config	cpu_pll;
+	struct ar934x_pll_config	ddr_pll;
+};
+
+static const struct ar934x_clock_config ar934x_clock_config[] = {
+	{ 300, 300, 150, { 1, 1, 1, { 24, 15 } }, { 1, 1, 1, { 24, 15 } } },
+	{ 400, 200, 200, { 1, 1, 1, { 32, 20 } }, { 1, 1, 2, { 32, 20 } } },
+	{ 400, 400, 200, { 0, 1, 1, { 32, 20 } }, { 0, 1, 1, { 32, 20 } } },
+	{ 500, 400, 200, { 1, 1, 0, { 20, 12 } }, { 0, 1, 1, { 32, 20 } } },
+	{ 533, 400, 200, { 1, 1, 0, { 21, 13 } }, { 0, 1, 1, { 32, 20 } } },
+	{ 533, 500, 250, { 1, 1, 0, { 21, 13 } }, { 0, 1, 0, { 20, 12 } } },
+	{ 560, 480, 240, { 1, 1, 0, { 22, 14 } }, { 1, 1, 0, { 19, 12 } } },
+	{ 566, 400, 200, { 1, 1, 0, { 22, 14 } }, { 1, 1, 0, { 16, 10 } } },
+	{ 566, 450, 225, { 1, 1, 0, { 22, 14 } }, { 0, 1, 1, { 36, 22 } } },
+	{ 566, 475, 237, { 1, 1, 0, { 22, 14 } }, { 1, 1, 0, { 19, 11 } } },
+	{ 566, 500, 250, { 1, 1, 0, { 22, 14 } }, { 1, 1, 0, { 20, 12 } } },
+	{ 566, 525, 262, { 1, 1, 0, { 22, 14 } }, { 1, 1, 0, { 21, 13 } } },
+	{ 566, 550, 275, { 1, 1, 0, { 22, 14 } }, { 1, 1, 0, { 22, 13 } } },
+	{ 600, 266, 133, { 0, 1, 0, { 24, 15 } }, { 1, 1, 1, { 21, 16 } } },
+	{ 600, 266, 200, { 0, 1, 0, { 24, 15 } }, { 1, 1, 1, { 21, 16 } } },
+	{ 600, 300, 150, { 0, 1, 0, { 24, 15 } }, { 0, 1, 1, { 24, 15 } } },
+	{ 600, 332, 166, { 0, 1, 0, { 24, 15 } }, { 1, 1, 1, { 26, 16 } } },
+	{ 600, 332, 200, { 0, 1, 0, { 24, 15 } }, { 1, 1, 1, { 26, 16 } } },
+	{ 600, 400, 200, { 0, 1, 0, { 24, 15 } }, { 0, 1, 1, { 32, 20 } } },
+	{ 600, 450, 200, { 0, 1, 0, { 24, 15 } }, { 0, 1, 0, { 18, 20 } } },
+	{ 600, 500, 250, { 0, 1, 0, { 24, 15 } }, { 1, 1, 0, { 20, 12 } } },
+	{ 600, 525, 262, { 0, 1, 0, { 24, 15 } }, { 0, 1, 0, { 21, 20 } } },
+	{ 600, 550, 275, { 0, 1, 0, { 24, 15 } }, { 0, 1, 0, { 22, 20 } } },
+	{ 600, 575, 287, { 0, 1, 0, { 24, 15 } }, { 0, 1, 0, { 23, 14 } } },
+	{ 600, 600, 300, { 0, 1, 0, { 24, 15 } }, { 0, 1, 0, { 24, 20 } } },
+	{ 600, 650, 325, { 0, 1, 0, { 24, 15 } }, { 0, 1, 0, { 26, 20 } } },
+	{ 650, 600, 300, { 0, 1, 0, { 26, 15 } }, { 0, 1, 0, { 24, 20 } } },
+	{ 700, 400, 200, { 3, 1, 0, { 28, 17 } }, { 0, 1, 1, { 32, 20 } } },
+};
+
+static void ar934x_srif_pll_cfg(void __iomem *pll_reg_base, const u32 srif_val)
+{
+	u32 reg;
+	do {
+		writel(0x10810f00, pll_reg_base + 0x4);
+		writel(srif_val, pll_reg_base + 0x0);
+		writel(0xd0810f00, pll_reg_base + 0x4);
+		writel(0x03000000, pll_reg_base + 0x8);
+		writel(0xd0800f00, pll_reg_base + 0x4);
+
+		clrbits_be32(pll_reg_base + 0x8, BIT(30));
+		udelay(5);
+		setbits_be32(pll_reg_base + 0x8, BIT(30));
+		udelay(5);
+
+		wait_for_bit("clk", pll_reg_base + 0xc, BIT(3), 1, 10, 0);
+
+		clrbits_be32(pll_reg_base + 0x8, BIT(30));
+		udelay(5);
+
+		/* Check if CPU SRIF PLL locked. */
+		reg = readl(pll_reg_base + 0x8);
+		reg = (reg & 0x7ffff8) >> 3;
+	} while (reg >= 0x40000);
+}
+
+void ar934x_pll_init(const u16 cpu_mhz, const u16 ddr_mhz, const u16 ahb_mhz)
+{
+	void __iomem *srif_regs = map_physmem(AR934X_SRIF_BASE,
+					      AR934X_SRIF_SIZE, MAP_NOCACHE);
+	void __iomem *pll_regs = map_physmem(AR71XX_PLL_BASE,
+					     AR71XX_PLL_SIZE, MAP_NOCACHE);
+	const struct ar934x_pll_config *pll_cfg;
+	int i, pll_nint, pll_refdiv, xtal_40 = 0;
+	u32 reg, cpu_pll, cpu_srif, ddr_pll, ddr_srif;
+
+	/* Configure SRIF PLL with initial values. */
+	writel(0x13210f00, srif_regs + AR934X_SRIF_CPU_DPLL2_REG);
+	writel(0x03000000, srif_regs + AR934X_SRIF_CPU_DPLL3_REG);
+	writel(0x13210f00, srif_regs + AR934X_SRIF_DDR_DPLL2_REG);
+	writel(0x03000000, srif_regs + AR934X_SRIF_DDR_DPLL3_REG);
+	writel(0x03000000, srif_regs + 0x188); /* Undocumented reg :-) */
+
+	/* Test for 40MHz XTAL */
+	reg = get_bootstrap();
+	if (reg & AR934X_BOOTSTRAP_REF_CLK_40) {
+		xtal_40 = 1;
+		cpu_srif = 0x41c00000;
+		ddr_srif = 0x41680000;
+	} else {
+		xtal_40 = 0;
+		cpu_srif = 0x29c00000;
+		ddr_srif = 0x29680000;
+	}
+
+	/* Locate CPU/DDR PLL configuration */
+	for (i = 0; i < ARRAY_SIZE(ar934x_clock_config); i++) {
+		if (cpu_mhz != ar934x_clock_config[i].cpu_freq)
+			continue;
+		if (ddr_mhz != ar934x_clock_config[i].ddr_freq)
+			continue;
+		if (ahb_mhz != ar934x_clock_config[i].ahb_freq)
+			continue;
+
+		/* Entry found */
+		pll_cfg = &ar934x_clock_config[i].cpu_pll;
+		pll_nint = pll_cfg->nint[xtal_40];
+		pll_refdiv = pll_cfg->refdiv;
+		cpu_pll =
+			(pll_nint << AR934X_PLL_CPU_CONFIG_NINT_SHIFT) |
+			(pll_refdiv << AR934X_PLL_CPU_CONFIG_REFDIV_SHIFT) |
+			(pll_cfg->range << AR934X_PLL_CPU_CONFIG_RANGE_SHIFT) |
+			(pll_cfg->outdiv << AR934X_PLL_CPU_CONFIG_OUTDIV_SHIFT);
+
+		pll_cfg = &ar934x_clock_config[i].ddr_pll;
+		pll_nint = pll_cfg->nint[xtal_40];
+		pll_refdiv = pll_cfg->refdiv;
+		ddr_pll =
+			(pll_nint << AR934X_PLL_DDR_CONFIG_NINT_SHIFT) |
+			(pll_refdiv << AR934X_PLL_DDR_CONFIG_REFDIV_SHIFT) |
+			(pll_cfg->range << AR934X_PLL_DDR_CONFIG_RANGE_SHIFT) |
+			(pll_cfg->outdiv << AR934X_PLL_DDR_CONFIG_OUTDIV_SHIFT);
+		break;
+	}
+
+	/* PLL configuration not found, hang. */
+	if (i == ARRAY_SIZE(ar934x_clock_config))
+		hang();
+
+	/* Set PLL Bypass */
+	setbits_be32(pll_regs + AR934X_PLL_CPU_DDR_CLK_CTRL_REG,
+		     AR934X_PLL_CLK_CTRL_CPU_PLL_BYPASS);
+	setbits_be32(pll_regs + AR934X_PLL_CPU_DDR_CLK_CTRL_REG,
+		     AR934X_PLL_CLK_CTRL_DDR_PLL_BYPASS);
+	setbits_be32(pll_regs + AR934X_PLL_CPU_DDR_CLK_CTRL_REG,
+		     AR934X_PLL_CLK_CTRL_AHB_PLL_BYPASS);
+
+	/* Configure CPU PLL */
+	writel(cpu_pll | AR934X_PLL_CPU_CONFIG_PLLPWD,
+	       pll_regs + AR934X_PLL_CPU_CONFIG_REG);
+	/* Configure DDR PLL */
+	writel(ddr_pll | AR934X_PLL_DDR_CONFIG_PLLPWD,
+	       pll_regs + AR934X_PLL_DDR_CONFIG_REG);
+	/* Configure PLL routing */
+	writel(AR934X_PLL_CLK_CTRL_CPU_PLL_BYPASS |
+	       AR934X_PLL_CLK_CTRL_DDR_PLL_BYPASS |
+	       AR934X_PLL_CLK_CTRL_AHB_PLL_BYPASS |
+	       (0 << AR934X_PLL_CLK_CTRL_CPU_POST_DIV_SHIFT) |
+	       (0 << AR934X_PLL_CLK_CTRL_DDR_POST_DIV_SHIFT) |
+	       (1 << AR934X_PLL_CLK_CTRL_AHB_POST_DIV_SHIFT) |
+	       AR934X_PLL_CLK_CTRL_CPUCLK_FROM_CPUPLL |
+	       AR934X_PLL_CLK_CTRL_DDRCLK_FROM_DDRPLL |
+	       AR934X_PLL_CLK_CTRL_AHBCLK_FROM_DDRPLL,
+	       pll_regs + AR934X_PLL_CPU_DDR_CLK_CTRL_REG);
+
+	/* Configure SRIF PLLs, which is completely undocumented :-) */
+	ar934x_srif_pll_cfg(srif_regs + AR934X_SRIF_CPU_DPLL1_REG, cpu_srif);
+	ar934x_srif_pll_cfg(srif_regs + AR934X_SRIF_DDR_DPLL1_REG, ddr_srif);
+
+	/* Unset PLL Bypass */
+	clrbits_be32(pll_regs + AR934X_PLL_CPU_DDR_CLK_CTRL_REG,
+		     AR934X_PLL_CLK_CTRL_CPU_PLL_BYPASS);
+	clrbits_be32(pll_regs + AR934X_PLL_CPU_DDR_CLK_CTRL_REG,
+		     AR934X_PLL_CLK_CTRL_DDR_PLL_BYPASS);
+	clrbits_be32(pll_regs + AR934X_PLL_CPU_DDR_CLK_CTRL_REG,
+		     AR934X_PLL_CLK_CTRL_AHB_PLL_BYPASS);
+
+	/* Enable PLL dithering */
+	writel((1 << AR934X_PLL_DDR_DIT_FRAC_STEP_SHIFT) |
+	       (0xf << AR934X_PLL_DDR_DIT_UPD_CNT_SHIFT),
+	       pll_regs + AR934X_PLL_DDR_DIT_FRAC_REG);
+	writel(48 << AR934X_PLL_CPU_DIT_UPD_CNT_SHIFT,
+	       pll_regs + AR934X_PLL_CPU_DIT_FRAC_REG);
+}
+
+static u32 ar934x_get_xtal(void)
+{
+	u32 val;
+
+	val = get_bootstrap();
+	if (val & AR934X_BOOTSTRAP_REF_CLK_40)
+		return 40000000;
+	else
+		return 25000000;
+}
+
+int get_serial_clock(void)
+{
+	return ar934x_get_xtal();
+}
+
+static u32 ar934x_cpupll_to_hz(const u32 regval)
+{
+	const u32 outdiv = (regval >> AR934X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
+			   AR934X_PLL_CPU_CONFIG_OUTDIV_MASK;
+	const u32 refdiv = (regval >> AR934X_PLL_CPU_CONFIG_REFDIV_SHIFT) &
+			   AR934X_PLL_CPU_CONFIG_REFDIV_MASK;
+	const u32 nint = (regval >> AR934X_PLL_CPU_CONFIG_NINT_SHIFT) &
+			   AR934X_PLL_CPU_CONFIG_NINT_MASK;
+	const u32 nfrac = (regval >> AR934X_PLL_CPU_CONFIG_NFRAC_SHIFT) &
+			   AR934X_PLL_CPU_CONFIG_NFRAC_MASK;
+	const u32 xtal = ar934x_get_xtal();
+
+	return (xtal * (nint + (nfrac >> 9))) / (refdiv * (1 << outdiv));
+}
+
+static u32 ar934x_ddrpll_to_hz(const u32 regval)
+{
+	const u32 outdiv = (regval >> AR934X_PLL_DDR_CONFIG_OUTDIV_SHIFT) &
+			   AR934X_PLL_DDR_CONFIG_OUTDIV_MASK;
+	const u32 refdiv = (regval >> AR934X_PLL_DDR_CONFIG_REFDIV_SHIFT) &
+			   AR934X_PLL_DDR_CONFIG_REFDIV_MASK;
+	const u32 nint = (regval >> AR934X_PLL_DDR_CONFIG_NINT_SHIFT) &
+			   AR934X_PLL_DDR_CONFIG_NINT_MASK;
+	const u32 nfrac = (regval >> AR934X_PLL_DDR_CONFIG_NFRAC_SHIFT) &
+			   AR934X_PLL_DDR_CONFIG_NFRAC_MASK;
+	const u32 xtal = ar934x_get_xtal();
+
+	return (xtal * (nint + (nfrac >> 9))) / (refdiv * (1 << outdiv));
+}
+
+static void ar934x_update_clock(void)
+{
+	void __iomem *regs;
+	u32 ctrl, cpu, cpupll, ddr, ddrpll;
+	u32 cpudiv, ddrdiv, busdiv;
+	u32 cpuclk, ddrclk, busclk;
+
+	regs = map_physmem(AR71XX_PLL_BASE, AR71XX_PLL_SIZE,
+			   MAP_NOCACHE);
+
+	cpu = readl(regs + AR934X_PLL_CPU_CONFIG_REG);
+	ddr = readl(regs + AR934X_PLL_DDR_CONFIG_REG);
+	ctrl = readl(regs + AR934X_PLL_CPU_DDR_CLK_CTRL_REG);
+
+	cpupll = ar934x_cpupll_to_hz(cpu);
+	ddrpll = ar934x_ddrpll_to_hz(ddr);
+
+	if (ctrl & AR934X_PLL_CLK_CTRL_CPU_PLL_BYPASS)
+		cpuclk = ar934x_get_xtal();
+	else if (ctrl & AR934X_PLL_CLK_CTRL_CPUCLK_FROM_CPUPLL)
+		cpuclk = cpupll;
+	else
+		cpuclk = ddrpll;
+
+	if (ctrl & AR934X_PLL_CLK_CTRL_DDR_PLL_BYPASS)
+		ddrclk = ar934x_get_xtal();
+	else if (ctrl & AR934X_PLL_CLK_CTRL_DDRCLK_FROM_DDRPLL)
+		ddrclk = ddrpll;
+	else
+		ddrclk = cpupll;
+
+	if (ctrl & AR934X_PLL_CLK_CTRL_AHB_PLL_BYPASS)
+		busclk = ar934x_get_xtal();
+	else if (ctrl & AR934X_PLL_CLK_CTRL_AHBCLK_FROM_DDRPLL)
+		busclk = ddrpll;
+	else
+		busclk = cpupll;
+
+	cpudiv = (ctrl >> AR934X_PLL_CLK_CTRL_CPU_POST_DIV_SHIFT) &
+		 AR934X_PLL_CLK_CTRL_CPU_POST_DIV_MASK;
+	ddrdiv = (ctrl >> AR934X_PLL_CLK_CTRL_DDR_POST_DIV_SHIFT) &
+		 AR934X_PLL_CLK_CTRL_DDR_POST_DIV_MASK;
+	busdiv = (ctrl >> AR934X_PLL_CLK_CTRL_AHB_POST_DIV_SHIFT) &
+		 AR934X_PLL_CLK_CTRL_AHB_POST_DIV_MASK;
+
+	gd->cpu_clk = cpuclk / (cpudiv + 1);
+	gd->mem_clk = ddrclk / (ddrdiv + 1);
+	gd->bus_clk = busclk / (busdiv + 1);
+}
+
+ulong get_bus_freq(ulong dummy)
+{
+	ar934x_update_clock();
+	return gd->bus_clk;
+}
+
+ulong get_ddr_freq(ulong dummy)
+{
+	ar934x_update_clock();
+	return gd->mem_clk;
+}
+
+int do_ar934x_showclk(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	ar934x_update_clock();
+	printf("CPU:       %8ld MHz\n", gd->cpu_clk / 1000000);
+	printf("Memory:    %8ld MHz\n", gd->mem_clk / 1000000);
+	printf("AHB:       %8ld MHz\n", gd->bus_clk / 1000000);
+	return 0;
+}
+
+U_BOOT_CMD(
+	clocks,	CONFIG_SYS_MAXARGS, 1, do_ar934x_showclk,
+	"display clocks",
+	""
+);
diff --git a/arch/mips/mach-ath79/ar934x/cpu.c b/arch/mips/mach-ath79/ar934x/cpu.c
new file mode 100644
index 0000000000..8fcdf657d1
--- /dev/null
+++ b/arch/mips/mach-ath79/ar934x/cpu.c
@@ -0,0 +1,10 @@
+/*
+ * Copyright (C) 2016 Marek Vasut <marex@denx.de>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+
+/* The lowlevel_init() is not needed on AR934x */
+void lowlevel_init(void) {}
diff --git a/arch/mips/mach-ath79/ar934x/ddr.c b/arch/mips/mach-ath79/ar934x/ddr.c
new file mode 100644
index 0000000000..4621d5845c
--- /dev/null
+++ b/arch/mips/mach-ath79/ar934x/ddr.c
@@ -0,0 +1,163 @@
+/*
+ * Copyright (C) 2016 Marek Vasut <marex@denx.de>
+ *
+ * Based on RAM init sequence by Piotr Dymacz <pepe2k@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/addrspace.h>
+#include <asm/types.h>
+#include <mach/ar71xx_regs.h>
+#include <mach/reset.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+enum {
+	AR934X_SDRAM = 0,
+	AR934X_DDR1,
+	AR934X_DDR2,
+};
+
+struct ar934x_mem_config {
+	u32	config1;
+	u32	config2;
+	u32	mode;
+	u32	extmode;
+	u32	tap;
+};
+
+static const struct ar934x_mem_config ar934x_mem_config[] = {
+	[AR934X_SDRAM] = { 0x7fbe8cd0, 0x959f66a8, 0x33, 0, 0x1f1f },
+	[AR934X_DDR1]  = { 0x7fd48cd0, 0x99d0e6a8, 0x33, 0, 0x14 },
+	[AR934X_DDR2]  = { 0xc7d48cd0, 0x9dd0e6a8, 0x33, 0, 0x10012 },
+};
+
+void ar934x_ddr_init(const u16 cpu_mhz, const u16 ddr_mhz, const u16 ahb_mhz)
+{
+	void __iomem *ddr_regs;
+	const struct ar934x_mem_config *memcfg;
+	int memtype;
+	u32 reg, cycle, ctl;
+
+	ddr_regs = map_physmem(AR71XX_DDR_CTRL_BASE, AR71XX_DDR_CTRL_SIZE,
+			       MAP_NOCACHE);
+
+	reg = get_bootstrap();
+	if (reg & AR934X_BOOTSTRAP_SDRAM_DISABLED) {	/* DDR */
+		if (reg & AR934X_BOOTSTRAP_DDR1) {	/* DDR 1 */
+			memtype = AR934X_DDR1;
+			cycle = 0xffff;
+		} else {				/* DDR 2 */
+			memtype = AR934X_DDR2;
+			if (gd->arch.rev) {
+				ctl = BIT(6);	/* Undocumented bit :-( */
+				if (reg & BIT(3))
+					cycle = 0xff;
+				else
+					cycle = 0xffff;
+			} else {
+				/* Force DDR2/x16 configuratio on old chips. */
+				ctl = 0;
+				cycle = 0xffff;		/* DDR2 16bit */
+			}
+
+			writel(0xe59, ddr_regs + AR934X_DDR_REG_DDR2_CONFIG);
+			udelay(100);
+
+			writel(0x10, ddr_regs + AR71XX_DDR_REG_CONTROL);
+			udelay(10);
+
+			writel(0x20, ddr_regs + AR71XX_DDR_REG_CONTROL);
+			udelay(10);
+
+			writel(ctl, ddr_regs + AR934X_DDR_REG_CTL_CONF);
+			udelay(10);
+		}
+	} else {					/* SDRAM */
+		memtype = AR934X_SDRAM;
+		cycle = 0xffffffff;
+
+		writel(0x13b, ddr_regs + AR934X_DDR_REG_CTL_CONF);
+		udelay(100);
+
+		/* Undocumented register */
+		writel(0x13b, ddr_regs + 0x118);
+		udelay(100);
+	}
+
+	memcfg = &ar934x_mem_config[memtype];
+
+	writel(memcfg->config1, ddr_regs + AR71XX_DDR_REG_CONFIG);
+	udelay(100);
+
+	writel(memcfg->config2, ddr_regs + AR71XX_DDR_REG_CONFIG2);
+	udelay(100);
+
+	writel(0x8, ddr_regs + AR71XX_DDR_REG_CONTROL);
+	udelay(10);
+
+	writel(memcfg->mode | 0x100, ddr_regs + AR71XX_DDR_REG_MODE);
+	mdelay(1);
+
+	writel(0x1, ddr_regs + AR71XX_DDR_REG_CONTROL);
+	udelay(10);
+
+	if (memtype == AR934X_DDR2) {
+		writel(memcfg->mode | 0x100, ddr_regs + AR71XX_DDR_REG_EMR);
+		udelay(100);
+
+		writel(0x2, ddr_regs + AR71XX_DDR_REG_CONTROL);
+		udelay(10);
+	}
+
+	if (memtype != AR934X_SDRAM)
+		writel(0x402, ddr_regs + AR71XX_DDR_REG_EMR);
+
+	udelay(100);
+
+	writel(0x2, ddr_regs + AR71XX_DDR_REG_CONTROL);
+	udelay(10);
+
+	writel(0x8, ddr_regs + AR71XX_DDR_REG_CONTROL);
+	udelay(10);
+
+	writel(memcfg->mode, ddr_regs + AR71XX_DDR_REG_MODE);
+	udelay(100);
+
+	writel(0x1, ddr_regs + AR71XX_DDR_REG_CONTROL);
+	udelay(10);
+
+	writel(0x412c /* FIXME */, ddr_regs + AR71XX_DDR_REG_REFRESH);
+	udelay(100);
+
+	writel(memcfg->tap, ddr_regs + AR71XX_DDR_REG_TAP_CTRL0);
+	writel(memcfg->tap, ddr_regs + AR71XX_DDR_REG_TAP_CTRL1);
+
+	if (memtype != AR934X_SDRAM) {
+		if ((gd->arch.rev && (reg & BIT(3))) || !gd->arch.rev) {
+			writel(memcfg->tap,
+			       ddr_regs + AR934X_DDR_REG_TAP_CTRL2);
+			writel(memcfg->tap,
+			       ddr_regs + AR934X_DDR_REG_TAP_CTRL3);
+		}
+	}
+
+	writel(cycle, ddr_regs + AR71XX_DDR_REG_RD_CYCLE);
+	udelay(100);
+
+	writel(0x74444444, ddr_regs + AR934X_DDR_REG_BURST);
+	udelay(100);
+
+	writel(0x222, ddr_regs + AR934X_DDR_REG_BURST2);
+	udelay(100);
+
+	writel(0xfffff, ddr_regs + AR934X_DDR_REG_TIMEOUT_MAX);
+	udelay(100);
+}
+
+void ddr_tap_tuning(void)
+{
+}