M28: Add MMC SPL

This patch adds SPL code for the M28 board.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Andy Fleming <afleming@gmail.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Detlev Zundel <dzu@denx.de>
diff --git a/board/denx/m28evk/mem_init.c b/board/denx/m28evk/mem_init.c
new file mode 100644
index 0000000..066fe0d
--- /dev/null
+++ b/board/denx/m28evk/mem_init.c
@@ -0,0 +1,213 @@
+/*
+ * Freescale i.MX28 RAM init
+ *
+ * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
+ * on behalf of DENX Software Engineering GmbH
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <config.h>
+#include <asm/io.h>
+#include <asm/arch/iomux-mx28.h>
+#include <asm/arch/imx-regs.h>
+
+#include "m28_init.h"
+
+uint32_t dram_vals[] = {
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000100, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00010101, 0x01010101, 0x000f0f01, 0x0f02020a,
+	0x00000000, 0x00010101, 0x00000100, 0x00000100, 0x00000000,
+	0x00000002, 0x01010000, 0x05060302, 0x06005003, 0x0a0000c8,
+	0x02009c40, 0x0000030c, 0x0036a609, 0x031a0612, 0x02030202,
+	0x00c8001c, 0x00000000, 0x00000000, 0x00012100, 0xffff0303,
+	0x00012100, 0xffff0303, 0x00012100, 0xffff0303, 0x00012100,
+	0xffff0303, 0x00000003, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000612, 0x01000F02, 0x06120612, 0x00000200,
+	0x00020007, 0xf5014b27, 0xf5014b27, 0xf5014b27, 0xf5014b27,
+	0x07000300, 0x07000300, 0x07000300, 0x07000300, 0x00000006,
+	0x00000000, 0x00000000, 0x01000000, 0x01020408, 0x08040201,
+	0x000f1133, 0x00000000, 0x00001f04, 0x00001f04, 0x00001f04,
+	0x00001f04, 0x00001f04, 0x00001f04, 0x00001f04, 0x00001f04,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x00000000, 0x00010000, 0x00020304, 0x00000004,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+	0x00000000, 0x01010000, 0x01000000, 0x03030000, 0x00010303,
+	0x01020202, 0x00000000, 0x02040303, 0x21002103, 0x00061200,
+	0x06120612, 0x04320432, 0x04320432, 0x00040004, 0x00040004,
+	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00010001
+};
+
+void init_m28_200mhz_ddr2(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(dram_vals); i++)
+		writel(dram_vals[i], MXS_DRAM_BASE + (4 * i));
+}
+
+void mx28_mem_init_clock(void)
+{
+	struct mx28_clkctrl_regs *clkctrl_regs =
+		(struct mx28_clkctrl_regs *)MXS_CLKCTRL_BASE;
+
+	/* Gate EMI clock */
+	writel(CLKCTRL_FRAC0_CLKGATEEMI,
+		&clkctrl_regs->hw_clkctrl_frac0_set);
+
+	/* EMI = 205MHz */
+	writel(CLKCTRL_FRAC0_EMIFRAC_MASK,
+		&clkctrl_regs->hw_clkctrl_frac0_set);
+	writel((0x2a << CLKCTRL_FRAC0_EMIFRAC_OFFSET) &
+		CLKCTRL_FRAC0_EMIFRAC_MASK,
+		&clkctrl_regs->hw_clkctrl_frac0_clr);
+
+	/* Ungate EMI clock */
+	writel(CLKCTRL_FRAC0_CLKGATEEMI,
+		&clkctrl_regs->hw_clkctrl_frac0_clr);
+
+	early_delay(11000);
+
+	writel((2 << CLKCTRL_EMI_DIV_EMI_OFFSET) |
+		(1 << CLKCTRL_EMI_DIV_XTAL_OFFSET),
+		&clkctrl_regs->hw_clkctrl_emi);
+
+	/* Unbypass EMI */
+	writel(CLKCTRL_CLKSEQ_BYPASS_EMI,
+		&clkctrl_regs->hw_clkctrl_clkseq_clr);
+
+	early_delay(10000);
+}
+
+void mx28_mem_setup_cpu_and_hbus(void)
+{
+	struct mx28_clkctrl_regs *clkctrl_regs =
+		(struct mx28_clkctrl_regs *)MXS_CLKCTRL_BASE;
+
+	/* CPU = 454MHz and ungate CPU clock */
+	clrsetbits_le32(&clkctrl_regs->hw_clkctrl_frac0,
+		CLKCTRL_FRAC0_CPUFRAC_MASK | CLKCTRL_FRAC0_CLKGATECPU,
+		19 << CLKCTRL_FRAC0_CPUFRAC_OFFSET);
+
+	/* Set CPU bypass */
+	writel(CLKCTRL_CLKSEQ_BYPASS_CPU,
+		&clkctrl_regs->hw_clkctrl_clkseq_set);
+
+	/* HBUS = 151MHz */
+	writel(CLKCTRL_HBUS_DIV_MASK, &clkctrl_regs->hw_clkctrl_hbus_set);
+	writel(((~3) << CLKCTRL_HBUS_DIV_OFFSET) & CLKCTRL_HBUS_DIV_MASK,
+		&clkctrl_regs->hw_clkctrl_hbus_clr);
+
+	early_delay(10000);
+
+	/* CPU clock divider = 1 */
+	clrsetbits_le32(&clkctrl_regs->hw_clkctrl_cpu,
+			CLKCTRL_CPU_DIV_CPU_MASK, 1);
+
+	/* Disable CPU bypass */
+	writel(CLKCTRL_CLKSEQ_BYPASS_CPU,
+		&clkctrl_regs->hw_clkctrl_clkseq_clr);
+}
+
+void mx28_mem_setup_vdda(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+
+	writel((0xc << POWER_VDDACTRL_TRG_OFFSET) |
+		(0x7 << POWER_VDDACTRL_BO_OFFSET_OFFSET) |
+		POWER_VDDACTRL_LINREG_OFFSET_1STEPS_BELOW,
+		&power_regs->hw_power_vddactrl);
+}
+
+void mx28_mem_setup_vddd(void)
+{
+	struct mx28_power_regs *power_regs =
+		(struct mx28_power_regs *)MXS_POWER_BASE;
+
+	writel((0x1c << POWER_VDDDCTRL_TRG_OFFSET) |
+		(0x7 << POWER_VDDDCTRL_BO_OFFSET_OFFSET) |
+		POWER_VDDDCTRL_LINREG_OFFSET_1STEPS_BELOW,
+		&power_regs->hw_power_vdddctrl);
+}
+
+void mx28_mem_init(void)
+{
+	struct mx28_clkctrl_regs *clkctrl_regs =
+		(struct mx28_clkctrl_regs *)MXS_CLKCTRL_BASE;
+	struct mx28_pinctrl_regs *pinctrl_regs =
+		(struct mx28_pinctrl_regs *)MXS_PINCTRL_BASE;
+
+	/* Set DDR2 mode */
+	writel(PINCTRL_EMI_DS_CTRL_DDR_MODE_DDR2,
+		&pinctrl_regs->hw_pinctrl_emi_ds_ctrl_set);
+
+	/* Power up PLL0 */
+	writel(CLKCTRL_PLL0CTRL0_POWER,
+		&clkctrl_regs->hw_clkctrl_pll0ctrl0_set);
+
+	early_delay(11000);
+
+	mx28_mem_init_clock();
+
+	mx28_mem_setup_vdda();
+
+	/*
+	 * Configure the DRAM registers
+	 */
+
+	/* Clear START bit from DRAM_CTL16 */
+	clrbits_le32(MXS_DRAM_BASE + 0x40, 1);
+
+	init_m28_200mhz_ddr2();
+
+	/* Clear SREFRESH bit from DRAM_CTL17 */
+	clrbits_le32(MXS_DRAM_BASE + 0x44, 1);
+
+	/* Set START bit in DRAM_CTL16 */
+	setbits_le32(MXS_DRAM_BASE + 0x40, 1);
+
+	/* Wait for bit 20 (DRAM init complete) in DRAM_CTL58 */
+	while (!(readl(MXS_DRAM_BASE + 0xe8) & (1 << 20)))
+		;
+
+	mx28_mem_setup_vddd();
+
+	early_delay(10000);
+
+	mx28_mem_setup_cpu_and_hbus();
+}