mx6: add mmdc configuration for MX6Q/MX6DL

- add function for configuring iomux based on board-specific regs
- add function for configuring mmdc based on board-specific and
  chip-specific data

Cc: Stefan Roese <sr@denx.de>
Cc: Otavio Salvador <otavio@ossystems.com.br>
Cc: Andy Ng <andreas2025@gmail.com>
Cc: Eric Nelson <eric.nelson@boundarydevices.com>
Cc: Tapani Utriainen <tapani@technexion.com>
Cc: Tom Rini <trini@ti.com>

Signed-off-by: Tim Harvey <tharvey@gateworks.com>

arch/arm/cpu/armv7/mx6/Makefile

@@ -8,4 +8,5 @@
 #
 
 obj-y	:= soc.o clock.o
+obj-$(CONFIG_SPL_BUILD)	     += ddr.o
 obj-$(CONFIG_SECURE_BOOT)    += hab.o

arch/arm/cpu/armv7/mx6/ddr.c

+/*
+ * Copyright (C) 2014 Gateworks Corporation
+ * Author: Tim Harvey <tharvey@gateworks.com>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <linux/types.h>
+#include <asm/arch/mx6-ddr.h>
+#include <asm/arch/sys_proto.h>
+#include <asm/io.h>
+#include <asm/types.h>
+
+#if defined(CONFIG_MX6QDL) || defined(CONFIG_MX6Q) || defined(CONFIG_MX6D)
+/* Configure MX6DQ mmdc iomux */
+void mx6dq_dram_iocfg(unsigned width,
+		      const struct mx6dq_iomux_ddr_regs *ddr,
+		      const struct mx6dq_iomux_grp_regs *grp)
+{
+	volatile struct mx6dq_iomux_ddr_regs *mx6_ddr_iomux;
+	volatile struct mx6dq_iomux_grp_regs *mx6_grp_iomux;
+
+	mx6_ddr_iomux = (struct mx6dq_iomux_ddr_regs *)MX6DQ_IOM_DDR_BASE;
+	mx6_grp_iomux = (struct mx6dq_iomux_grp_regs *)MX6DQ_IOM_GRP_BASE;
+
+	/* DDR IO Type */
+	mx6_grp_iomux->grp_ddr_type = grp->grp_ddr_type;
+	mx6_grp_iomux->grp_ddrpke = grp->grp_ddrpke;
+
+	/* Clock */
+	mx6_ddr_iomux->dram_sdclk_0 = ddr->dram_sdclk_0;
+	mx6_ddr_iomux->dram_sdclk_1 = ddr->dram_sdclk_1;
+
+	/* Address */
+	mx6_ddr_iomux->dram_cas = ddr->dram_cas;
+	mx6_ddr_iomux->dram_ras = ddr->dram_ras;
+	mx6_grp_iomux->grp_addds = grp->grp_addds;
+
+	/* Control */
+	mx6_ddr_iomux->dram_reset = ddr->dram_reset;
+	mx6_ddr_iomux->dram_sdcke0 = ddr->dram_sdcke0;
+	mx6_ddr_iomux->dram_sdcke1 = ddr->dram_sdcke1;
+	mx6_ddr_iomux->dram_sdba2 = ddr->dram_sdba2;
+	mx6_ddr_iomux->dram_sdodt0 = ddr->dram_sdodt0;
+	mx6_ddr_iomux->dram_sdodt1 = ddr->dram_sdodt1;
+	mx6_grp_iomux->grp_ctlds = grp->grp_ctlds;
+
+	/* Data Strobes */
+	mx6_grp_iomux->grp_ddrmode_ctl = grp->grp_ddrmode_ctl;
+	mx6_ddr_iomux->dram_sdqs0 = ddr->dram_sdqs0;
+	mx6_ddr_iomux->dram_sdqs1 = ddr->dram_sdqs1;
+	if (width >= 32) {
+		mx6_ddr_iomux->dram_sdqs2 = ddr->dram_sdqs2;
+		mx6_ddr_iomux->dram_sdqs3 = ddr->dram_sdqs3;
+	}
+	if (width >= 64) {
+		mx6_ddr_iomux->dram_sdqs4 = ddr->dram_sdqs4;
+		mx6_ddr_iomux->dram_sdqs5 = ddr->dram_sdqs5;
+		mx6_ddr_iomux->dram_sdqs6 = ddr->dram_sdqs6;
+		mx6_ddr_iomux->dram_sdqs7 = ddr->dram_sdqs7;
+	}
+
+	/* Data */
+	mx6_grp_iomux->grp_ddrmode = grp->grp_ddrmode;
+	mx6_grp_iomux->grp_b0ds = grp->grp_b0ds;
+	mx6_grp_iomux->grp_b1ds = grp->grp_b1ds;
+	if (width >= 32) {
+		mx6_grp_iomux->grp_b2ds = grp->grp_b2ds;
+		mx6_grp_iomux->grp_b3ds = grp->grp_b3ds;
+	}
+	if (width >= 64) {
+		mx6_grp_iomux->grp_b4ds = grp->grp_b4ds;
+		mx6_grp_iomux->grp_b5ds = grp->grp_b5ds;
+		mx6_grp_iomux->grp_b6ds = grp->grp_b6ds;
+		mx6_grp_iomux->grp_b7ds = grp->grp_b7ds;
+	}
+	mx6_ddr_iomux->dram_dqm0 = ddr->dram_dqm0;
+	mx6_ddr_iomux->dram_dqm1 = ddr->dram_dqm1;
+	if (width >= 32) {
+		mx6_ddr_iomux->dram_dqm2 = ddr->dram_dqm2;
+		mx6_ddr_iomux->dram_dqm3 = ddr->dram_dqm3;
+	}
+	if (width >= 64) {
+		mx6_ddr_iomux->dram_dqm4 = ddr->dram_dqm4;
+		mx6_ddr_iomux->dram_dqm5 = ddr->dram_dqm5;
+		mx6_ddr_iomux->dram_dqm6 = ddr->dram_dqm6;
+		mx6_ddr_iomux->dram_dqm7 = ddr->dram_dqm7;
+	}
+}
+#endif
+
+#if defined(CONFIG_MX6QDL) || defined(CONFIG_MX6DL) || defined(CONFIG_MX6S)
+/* Configure MX6SDL mmdc iomux */
+void mx6sdl_dram_iocfg(unsigned width,
+		       const struct mx6sdl_iomux_ddr_regs *ddr,
+		       const struct mx6sdl_iomux_grp_regs *grp)
+{
+	volatile struct mx6sdl_iomux_ddr_regs *mx6_ddr_iomux;
+	volatile struct mx6sdl_iomux_grp_regs *mx6_grp_iomux;
+
+	mx6_ddr_iomux = (struct mx6sdl_iomux_ddr_regs *)MX6SDL_IOM_DDR_BASE;
+	mx6_grp_iomux = (struct mx6sdl_iomux_grp_regs *)MX6SDL_IOM_GRP_BASE;
+
+	/* DDR IO Type */
+	mx6_grp_iomux->grp_ddr_type = grp->grp_ddr_type;
+	mx6_grp_iomux->grp_ddrpke = grp->grp_ddrpke;
+
+	/* Clock */
+	mx6_ddr_iomux->dram_sdclk_0 = ddr->dram_sdclk_0;
+	mx6_ddr_iomux->dram_sdclk_1 = ddr->dram_sdclk_1;
+
+	/* Address */
+	mx6_ddr_iomux->dram_cas = ddr->dram_cas;
+	mx6_ddr_iomux->dram_ras = ddr->dram_ras;
+	mx6_grp_iomux->grp_addds = grp->grp_addds;
+
+	/* Control */
+	mx6_ddr_iomux->dram_reset = ddr->dram_reset;
+	mx6_ddr_iomux->dram_sdcke0 = ddr->dram_sdcke0;
+	mx6_ddr_iomux->dram_sdcke1 = ddr->dram_sdcke1;
+	mx6_ddr_iomux->dram_sdba2 = ddr->dram_sdba2;
+	mx6_ddr_iomux->dram_sdodt0 = ddr->dram_sdodt0;
+	mx6_ddr_iomux->dram_sdodt1 = ddr->dram_sdodt1;
+	mx6_grp_iomux->grp_ctlds = grp->grp_ctlds;
+
+	/* Data Strobes */
+	mx6_grp_iomux->grp_ddrmode_ctl = grp->grp_ddrmode_ctl;
+	mx6_ddr_iomux->dram_sdqs0 = ddr->dram_sdqs0;
+	mx6_ddr_iomux->dram_sdqs1 = ddr->dram_sdqs1;
+	if (width >= 32) {
+		mx6_ddr_iomux->dram_sdqs2 = ddr->dram_sdqs2;
+		mx6_ddr_iomux->dram_sdqs3 = ddr->dram_sdqs3;
+	}
+	if (width >= 64) {
+		mx6_ddr_iomux->dram_sdqs4 = ddr->dram_sdqs4;
+		mx6_ddr_iomux->dram_sdqs5 = ddr->dram_sdqs5;
+		mx6_ddr_iomux->dram_sdqs6 = ddr->dram_sdqs6;
+		mx6_ddr_iomux->dram_sdqs7 = ddr->dram_sdqs7;
+	}
+
+	/* Data */
+	mx6_grp_iomux->grp_ddrmode = grp->grp_ddrmode;
+	mx6_grp_iomux->grp_b0ds = grp->grp_b0ds;
+	mx6_grp_iomux->grp_b1ds = grp->grp_b1ds;
+	if (width >= 32) {
+		mx6_grp_iomux->grp_b2ds = grp->grp_b2ds;
+		mx6_grp_iomux->grp_b3ds = grp->grp_b3ds;
+	}
+	if (width >= 64) {
+		mx6_grp_iomux->grp_b4ds = grp->grp_b4ds;
+		mx6_grp_iomux->grp_b5ds = grp->grp_b5ds;
+		mx6_grp_iomux->grp_b6ds = grp->grp_b6ds;
+		mx6_grp_iomux->grp_b7ds = grp->grp_b7ds;
+	}
+	mx6_ddr_iomux->dram_dqm0 = ddr->dram_dqm0;
+	mx6_ddr_iomux->dram_dqm1 = ddr->dram_dqm1;
+	if (width >= 32) {
+		mx6_ddr_iomux->dram_dqm2 = ddr->dram_dqm2;
+		mx6_ddr_iomux->dram_dqm3 = ddr->dram_dqm3;
+	}
+	if (width >= 64) {
+		mx6_ddr_iomux->dram_dqm4 = ddr->dram_dqm4;
+		mx6_ddr_iomux->dram_dqm5 = ddr->dram_dqm5;
+		mx6_ddr_iomux->dram_dqm6 = ddr->dram_dqm6;
+		mx6_ddr_iomux->dram_dqm7 = ddr->dram_dqm7;
+	}
+}
+#endif
+
+/*
+ * Configure mx6 mmdc registers based on:
+ *  - board-specific memory configuration
+ *  - board-specific calibration data
+ *  - ddr3 chip details
+ *
+ * The various calculations here are derived from the Freescale
+ * i.Mx6DQSDL DDR3 Script Aid spreadsheet (DOC-94917) designed to generate MMDC
+ * configuration registers based on memory system and memory chip parameters.
+ *
+ * The defaults here are those which were specified in the spreadsheet.
+ * For details on each register, refer to the IMX6DQRM and/or IMX6SDLRM
+ * section titled MMDC initialization
+ */
+#define MR(val, ba, cmd, cs1) \
+	((val << 16) | (1 << 15) | (cmd << 4) | (cs1 << 3) | ba)
+void mx6_dram_cfg(const struct mx6_ddr_sysinfo *i,
+		  const struct mx6_mmdc_calibration *c,
+		  const struct mx6_ddr3_cfg *m)
+{
+	volatile struct mmdc_p_regs *mmdc0;
+	volatile struct mmdc_p_regs *mmdc1;
+	u32 reg;
+	u8 tcke, tcksrx, tcksre, txpdll, taofpd, taonpd, trrd;
+	u8 todtlon, taxpd, tanpd, tcwl, txp, tfaw, tcl;
+	u8 todt_idle_off = 0x4; /* from DDR3 Script Aid spreadsheet */
+	u16 trcd, trc, tras, twr, tmrd, trtp, trp, twtr, trfc, txs, txpr;
+	u16 CS0_END;
+	u16 tdllk = 0x1ff; /* DLL locking time: 512 cycles (JEDEC DDR3) */
+	int clkper; /* clock period in picoseconds */
+	int clock; /* clock freq in mHz */
+	int cs;
+
+	mmdc0 = (struct mmdc_p_regs *)MMDC_P0_BASE_ADDR;
+	mmdc1 = (struct mmdc_p_regs *)MMDC_P1_BASE_ADDR;
+
+	/* MX6D/MX6Q: 1066 MHz memory clock, clkper = 1.894ns = 1894ps */
+	if (is_cpu_type(MXC_CPU_MX6Q) || is_cpu_type(MXC_CPU_MX6D)) {
+		clock = 528;
+		tcwl = 4;
+	}
+	/* MX6S/MX6DL: 800 MHz memory clock, clkper = 2.5ns = 2500ps */
+	else {
+		clock = 400;
+		tcwl = 3;
+	}
+	clkper = (1000*1000)/clock; /* ps */
+	todtlon = tcwl;
+	taxpd = tcwl;
+	tanpd = tcwl;
+	tcwl = tcwl;
+
+	switch (m->density) {
+	case 1: /* 1Gb per chip */
+		trfc = DIV_ROUND_UP(110000, clkper) - 1;
+		txs = DIV_ROUND_UP(120000, clkper) - 1;
+		break;
+	case 2: /* 2Gb per chip */
+		trfc = DIV_ROUND_UP(160000, clkper) - 1;
+		txs = DIV_ROUND_UP(170000, clkper) - 1;
+		break;
+	case 4: /* 4Gb per chip */
+		trfc = DIV_ROUND_UP(260000, clkper) - 1;
+		txs = DIV_ROUND_UP(270000, clkper) - 1;
+		break;
+	case 8: /* 8Gb per chip */
+		trfc = DIV_ROUND_UP(350000, clkper) - 1;
+		txs = DIV_ROUND_UP(360000, clkper) - 1;
+		break;
+	default:
+		/* invalid density */
+		printf("invalid chip density\n");
+		hang();
+		break;
+	}
+	txpr = txs;
+
+	switch (m->mem_speed) {
+	case 800:
+		txp = DIV_ROUND_UP(MAX(3*clkper, 7500), clkper) - 1;
+		tcke = DIV_ROUND_UP(MAX(3*clkper, 7500), clkper) - 1;
+		if (m->pagesz == 1) {
+			tfaw = DIV_ROUND_UP(40000, clkper) - 1;
+			trrd = DIV_ROUND_UP(MAX(4*clkper, 10000), clkper) - 1;
+		} else {
+			tfaw = DIV_ROUND_UP(50000, clkper) - 1;
+			trrd = DIV_ROUND_UP(MAX(4*clkper, 10000), clkper) - 1;
+		}
+		break;
+	case 1066:
+		txp = DIV_ROUND_UP(MAX(3*clkper, 7500), clkper) - 1;
+		tcke = DIV_ROUND_UP(MAX(3*clkper, 5625), clkper) - 1;
+		if (m->pagesz == 1) {
+			tfaw = DIV_ROUND_UP(37500, clkper) - 1;
+			trrd = DIV_ROUND_UP(MAX(4*clkper, 7500), clkper) - 1;
+		} else {
+			tfaw = DIV_ROUND_UP(50000, clkper) - 1;
+			trrd = DIV_ROUND_UP(MAX(4*clkper, 10000), clkper) - 1;
+		}
+		break;
+	case 1333:
+		txp = DIV_ROUND_UP(MAX(3*clkper, 6000), clkper) - 1;
+		tcke = DIV_ROUND_UP(MAX(3*clkper, 5625), clkper) - 1;
+		if (m->pagesz == 1) {
+			tfaw = DIV_ROUND_UP(30000, clkper) - 1;
+			trrd = DIV_ROUND_UP(MAX(4*clkper, 6000), clkper) - 1;
+		} else {
+			tfaw = DIV_ROUND_UP(45000, clkper) - 1;
+			trrd = DIV_ROUND_UP(MAX(4*clkper, 7500), clkper) - 1;
+		}
+		break;
+	case 1600:
+		txp = DIV_ROUND_UP(MAX(3*clkper, 6000), clkper) - 1;
+		tcke = DIV_ROUND_UP(MAX(3*clkper, 5000), clkper) - 1;
+		if (m->pagesz == 1) {
+			tfaw = DIV_ROUND_UP(30000, clkper) - 1;
+			trrd = DIV_ROUND_UP(MAX(4*clkper, 6000), clkper) - 1;
+		} else {
+			tfaw = DIV_ROUND_UP(40000, clkper) - 1;
+			trrd = DIV_ROUND_UP(MAX(4*clkper, 7500), clkper) - 1;
+		}
+		break;
+	default:
+		printf("invalid memory speed\n");
+		hang();
+		break;
+	}
+	txpdll = DIV_ROUND_UP(MAX(10*clkper, 24000), clkper) - 1;
+	tcl = DIV_ROUND_UP(m->trcd, clkper/10) - 3;
+	tcksre = DIV_ROUND_UP(MAX(5*clkper, 10000), clkper);
+	tcksrx = tcksre;
+	taonpd = DIV_ROUND_UP(2000, clkper) - 1;
+	taofpd = taonpd;
+	trp = DIV_ROUND_UP(m->trcd, clkper/10) - 1;
+	trcd = trp;
+	trc = DIV_ROUND_UP(m->trcmin, clkper/10) - 1;
+	tras = DIV_ROUND_UP(m->trasmin, clkper/10) - 1;
+	twr = DIV_ROUND_UP(15000, clkper) - 1;
+	tmrd = DIV_ROUND_UP(MAX(12*clkper, 15000), clkper) - 1;
+	twtr = ROUND(MAX(4*clkper, 7500)/clkper, 1) - 1;
+	trtp = twtr;
+	CS0_END = ((4*i->cs_density) <= 120) ? (4*i->cs_density)+7 : 127;
+	debug("density:%d Gb (%d Gb per chip)\n", i->cs_density, m->density);
+	debug("clock: %dMHz (%d ps)\n", clock, clkper);
+	debug("memspd:%d\n", m->mem_speed);
+	debug("tcke=%d\n", tcke);
+	debug("tcksrx=%d\n", tcksrx);
+	debug("tcksre=%d\n", tcksre);
+	debug("taofpd=%d\n", taofpd);
+	debug("taonpd=%d\n", taonpd);
+	debug("todtlon=%d\n", todtlon);
+	debug("tanpd=%d\n", tanpd);
+	debug("taxpd=%d\n", taxpd);
+	debug("trfc=%d\n", trfc);
+	debug("txs=%d\n", txs);
+	debug("txp=%d\n", txp);
+	debug("txpdll=%d\n", txpdll);
+	debug("tfaw=%d\n", tfaw);
+	debug("tcl=%d\n", tcl);
+	debug("trcd=%d\n", trcd);
+	debug("trp=%d\n", trp);
+	debug("trc=%d\n", trc);
+	debug("tras=%d\n", tras);
+	debug("twr=%d\n", twr);
+	debug("tmrd=%d\n", tmrd);
+	debug("tcwl=%d\n", tcwl);
+	debug("tdllk=%d\n", tdllk);
+	debug("trtp=%d\n", trtp);
+	debug("twtr=%d\n", twtr);
+	debug("trrd=%d\n", trrd);
+	debug("txpr=%d\n", txpr);
+	debug("CS0_END=%d\n", CS0_END);
+	debug("ncs=%d\n", i->ncs);
+	debug("Rtt_wr=%d\n", i->rtt_wr);
+	debug("Rtt_nom=%d\n", i->rtt_nom);
+	debug("SRT=%d\n", m->SRT);
+	debug("tcl=%d\n", tcl);
+	debug("twr=%d\n", twr);
+
+	/*
+	 * board-specific configuration:
+	 *  These values are determined empirically and vary per board layout
+	 *  see:
+	 *   appnote, ddr3 spreadsheet
+	 */
+	mmdc0->mpwldectrl0 = c->p0_mpwldectrl0;
+	mmdc0->mpwldectrl1 = c->p0_mpwldectrl1;
+	mmdc0->mpdgctrl0 = c->p0_mpdgctrl0;
+	mmdc0->mpdgctrl1 = c->p0_mpdgctrl1;
+	mmdc0->mprddlctl = c->p0_mprddlctl;
+	mmdc0->mpwrdlctl = c->p0_mpwrdlctl;
+	if (i->dsize > 1) {
+		mmdc1->mpwldectrl0 = c->p1_mpwldectrl0;
+		mmdc1->mpwldectrl1 = c->p1_mpwldectrl1;
+		mmdc1->mpdgctrl0 = c->p1_mpdgctrl0;
+		mmdc1->mpdgctrl1 = c->p1_mpdgctrl1;
+		mmdc1->mprddlctl = c->p1_mprddlctl;
+		mmdc1->mpwrdlctl = c->p1_mpwrdlctl;
+	}
+
+	/* Read data DQ Byte0-3 delay */
+	mmdc0->mprddqby0dl = (u32)0x33333333;
+	mmdc0->mprddqby1dl = (u32)0x33333333;
+	if (i->dsize > 0) {
+		mmdc0->mprddqby2dl = (u32)0x33333333;
+		mmdc0->mprddqby3dl = (u32)0x33333333;
+	}
+	if (i->dsize > 1) {
+		mmdc1->mprddqby0dl = (u32)0x33333333;
+		mmdc1->mprddqby1dl = (u32)0x33333333;
+		mmdc1->mprddqby2dl = (u32)0x33333333;
+		mmdc1->mprddqby3dl = (u32)0x33333333;
+	}
+
+	/* MMDC Termination: rtt_nom:2 RZQ/2(120ohm), rtt_nom:1 RZQ/4(60ohm) */
+	reg = (i->rtt_nom == 2) ? 0x00011117 : 0x00022227;
+	mmdc0->mpodtctrl = reg;
+	if (i->dsize > 1)
+		mmdc1->mpodtctrl = reg;
+
+	/* complete calibration */
+	reg = (1 << 11); /* Force measurement on delay-lines */
+	mmdc0->mpmur0 = reg;
+	if (i->dsize > 1)
+		mmdc1->mpmur0 = reg;
+
+	/* Step 1: configuration request */
+	mmdc0->mdscr = (u32)(1 << 15); /* config request */
+
+	/* Step 2: Timing configuration */
+	reg = (trfc << 24) | (txs << 16) | (txp << 13) | (txpdll << 9) |
+	      (tfaw << 4) | tcl;
+	mmdc0->mdcfg0 = reg;
+	reg = (trcd << 29) | (trp << 26) | (trc << 21) | (tras << 16) |
+	      (1 << 15) |		/* trpa */
+	      (twr << 9) | (tmrd << 5) | tcwl;
+	mmdc0->mdcfg1 = reg;
+	reg = (tdllk << 16) | (trtp << 6) | (twtr << 3) | trrd;
+	mmdc0->mdcfg2 = reg;
+	reg = (taofpd << 27) | (taonpd << 24) | (tanpd << 20) | (taxpd << 16) |
+	      (todtlon << 12) | (todt_idle_off << 4);
+	mmdc0->mdotc = reg;
+	mmdc0->mdasp = CS0_END; /* CS addressing */
+
+	/* Step 3: Configure DDR type */
+	reg = (i->cs1_mirror << 19) | (i->walat << 16) | (i->bi_on << 12) |
+	      (i->mif3_mode << 9) | (i->ralat << 6);
+	mmdc0->mdmisc = reg;
+
+	/* Step 4: Configure delay while leaving reset */
+	reg = (txpr << 16) | (i->sde_to_rst << 8) | (i->rst_to_cke << 0);
+	mmdc0->mdor = reg;
+
+	/* Step 5: Configure DDR physical parameters (density and burst len) */
+	reg = (m->rowaddr - 11) << 24 |		/* ROW */
+	      (m->coladdr - 9) << 20 |		/* COL */
+	      (1 << 19) |			/* Burst Length = 8 for DDR3 */
+	      (i->dsize << 16);			/* DDR data bus size */
+	mmdc0->mdctl = reg;
+
+	/* Step 6: Perform ZQ calibration */
+	reg = (u32)0xa1390001; /* one-time HW ZQ calib */
+	mmdc0->mpzqhwctrl = reg;
+	if (i->dsize > 1)
+		mmdc1->mpzqhwctrl = reg;
+
+	/* Step 7: Enable MMDC with desired chip select */
+	reg = mmdc0->mdctl |
+	      (1 << 31) |			/* SDE_0 for CS0 */
+	      ((i->ncs == 2) ? 1 : 0) << 30;	/* SDE_1 for CS1 */
+	mmdc0->mdctl = reg;
+
+	/* Step 8: Write Mode Registers to Init DDR3 devices */
+	for (cs = 0; cs < i->ncs; cs++) {
+		/* MR2 */
+		reg = (i->rtt_wr & 3) << 9 | (m->SRT & 1) << 7 |
+		      ((tcwl - 3) & 3) << 3;
+		mmdc0->mdscr = (u32)MR(reg, 2, 3, cs);
+		/* MR3 */
+		mmdc0->mdscr = (u32)MR(0, 3, 3, cs);
+		/* MR1 */
+		reg = ((i->rtt_nom & 1) ? 1 : 0) << 2 |
+		      ((i->rtt_nom & 2) ? 1 : 0) << 6;
+		mmdc0->mdscr = (u32)MR(reg, 1, 3, cs);
+		reg = ((tcl - 1) << 4) |	/* CAS */
+		      (1 << 8)   |		/* DLL Reset */
+		      ((twr - 3) << 9);		/* Write Recovery */
+		/* MR0 */
+		mmdc0->mdscr = (u32)MR(reg, 0, 3, cs);
+		/* ZQ calibration */
+		reg = (1 << 10);
+		mmdc0->mdscr = (u32)MR(reg, 0, 4, cs);
+	}
+
+	/* Step 10: Power down control and self-refresh */
+	reg = (tcke & 0x7) << 16 |
+	      5            << 12 |  /* PWDT_1: 256 cycles */
+	      5            <<  8 |  /* PWDT_0: 256 cycles */
+	      1            <<  6 |  /* BOTH_CS_PD */
+	      (tcksrx & 0x7) << 3 |
+	      (tcksre & 0x7);
+	mmdc0->mdpdc = reg;
+	mmdc0->mapsr = (u32)0x00011006; /* ADOPT power down enabled */
+
+	/* Step 11: Configure ZQ calibration: one-time and periodic 1ms */
+	mmdc0->mpzqhwctrl = (u32)0xa1390003;
+	if (i->dsize > 1)
+		mmdc1->mpzqhwctrl = (u32)0xa1390003;
+
+	/* Step 12: Configure and activate periodic refresh */
+	reg = (1 << 14) |	/* REF_SEL: Periodic refresh cycles of 32kHz */
+	      (7 << 11);	/* REFR: Refresh Rate - 8 refreshes */
+	mmdc0->mdref = reg;
+
+	/* Step 13: Deassert config request - init complete */
+	mmdc0->mdscr = (u32)0x00000000;
+
+	/* wait for auto-ZQ calibration to complete */
+	mdelay(1);
+}

arch/arm/include/asm/arch-mx6/mx6-ddr.h

@@ -173,6 +173,78 @@ struct mx6sdl_iomux_grp_regs {
 	u32 res4;
 	u32 grp_b6ds;
 };
+
+/* Device Information: Varies per DDR3 part number and speed grade */
+struct mx6_ddr3_cfg {
+	u16 mem_speed;	/* ie 1600 for DDR3-1600 (800,1066,1333,1600) */
+	u8 density;	/* chip density (Gb) (1,2,4,8) */
+	u8 width;	/* bus width (bits) (4,8,16) */
+	u8 banks;	/* number of banks */
+	u8 rowaddr;	/* row address bits (11-16)*/
+	u8 coladdr;	/* col address bits (9-12) */
+	u8 pagesz;	/* page size (K) (1-2) */
+	u16 trcd;	/* tRCD=tRP=CL (ns*100) */
+	u16 trcmin;	/* tRC min (ns*100) */
+	u16 trasmin;	/* tRAS min (ns*100) */
+	u8 SRT;		/* self-refresh temperature: 0=normal, 1=extended */
+};
+
+/* System Information: Varies per board design, layout, and term choices */
+struct mx6_ddr_sysinfo {
+	u8 dsize;	/* size of bus (in dwords: 0=16bit,1=32bit,2=64bit) */
+	u8 cs_density;	/* density per chip select (Gb) */
+	u8 ncs;		/* number chip selects used (1|2) */
+	char cs1_mirror;/* enable address mirror (0|1) */
+	char bi_on;	/* Bank interleaving enable */
+	u8 rtt_nom;	/* Rtt_Nom (DDR3_RTT_*) */
+	u8 rtt_wr;	/* Rtt_Wr (DDR3_RTT_*) */
+	u8 ralat;	/* Read Additional Latency (0-7) */
+	u8 walat;	/* Write Additional Latency (0-3) */
+	u8 mif3_mode;	/* Command prediction working mode */
+	u8 rst_to_cke;	/* Time from SDE enable to CKE rise */
+	u8 sde_to_rst;	/* Time from SDE enable until DDR reset# is high */
+};
+
+/*
+ * Board specific calibration:
+ *   This includes write leveling calibration values as well as DQS gating
+ *   and read/write delays. These values are board/layout/device specific.
+ *   Freescale recommends using the i.MX6 DDR Stress Test Tool V1.0.2
+ *   (DOC-96412) to determine these values over a range of boards and
+ *   temperatures.
+ */
+struct mx6_mmdc_calibration {
+	/* write leveling calibration */
+	u32 p0_mpwldectrl0;
+	u32 p0_mpwldectrl1;
+	u32 p1_mpwldectrl0;
+	u32 p1_mpwldectrl1;
+	/* read DQS gating */
+	u32 p0_mpdgctrl0;
+	u32 p0_mpdgctrl1;
+	u32 p1_mpdgctrl0;
+	u32 p1_mpdgctrl1;
+	/* read delay */
+	u32 p0_mprddlctl;
+	u32 p1_mprddlctl;
+	/* write delay */
+	u32 p0_mpwrdlctl;
+	u32 p1_mpwrdlctl;
+};
+
+/* configure iomux (pinctl/padctl) */
+void mx6dq_dram_iocfg(unsigned width,
+		      const struct mx6dq_iomux_ddr_regs *,
+		      const struct mx6dq_iomux_grp_regs *);
+void mx6sdl_dram_iocfg(unsigned width,
+		       const struct mx6sdl_iomux_ddr_regs *,
+		       const struct mx6sdl_iomux_grp_regs *);
+
+/* configure mx6 mmdc registers */
+void mx6_dram_cfg(const struct mx6_ddr_sysinfo *,
+		  const struct mx6_mmdc_calibration *,
+		  const struct mx6_ddr3_cfg *);
+
 #endif /* CONFIG_SPL_BUILD */
 
 #define MX6_MMDC_P0_MDCTL	0x021b0000