sun6i: Add dram initialization code

Add full support for dram initialization, using a fixed clock and autodetection
of the memory organization (numbers of channels, bus-width, etc.).

This is based on dram_sun6i.c and dram.h from u-boot in the Allwinner A31 SDK,
extended with extra initialization sequences and the autodetect algorithm
from boot0.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

2 files changed, 436 insertions, 0 deletions

diff --git a/arch/arm/cpu/armv7/sunxi/Makefile b/arch/arm/cpu/armv7/sunxi/Makefile
index 48cca0b..3b6ae47 100644
--- a/arch/arm/cpu/armv7/sunxi/Makefile
+++ b/arch/arm/cpu/armv7/sunxi/Makefile
@@ -30,6 +30,7 @@ endif
 ifdef CONFIG_SPL_BUILD
 obj-$(CONFIG_MACH_SUN4I)	+= dram_sun4i.o
 obj-$(CONFIG_MACH_SUN5I)	+= dram_sun4i.o
+obj-$(CONFIG_MACH_SUN6I)	+= dram_sun6i.o
 obj-$(CONFIG_MACH_SUN7I)	+= dram_sun4i.o
 ifdef CONFIG_SPL_FEL
 obj-y	+= start.o
diff --git a/arch/arm/cpu/armv7/sunxi/dram_sun6i.c b/arch/arm/cpu/armv7/sunxi/dram_sun6i.c
new file mode 100644
index 0000000..10a6241
--- /dev/null
+++ b/arch/arm/cpu/armv7/sunxi/dram_sun6i.c
@@ -0,0 +1,435 @@
+/*
+ * Sun6i platform dram controller init.
+ *
+ * (C) Copyright 2007-2012
+ * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
+ * Berg Xing <bergxing@allwinnertech.com>
+ * Tom Cubie <tangliang@allwinnertech.com>
+ *
+ * (C) Copyright 2014 Hans de Goede <hdegoede@redhat.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+#include <common.h>
+#include <errno.h>
+#include <asm/io.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/dram.h>
+#include <asm/arch/prcm.h>
+
+/* DRAM clk & zq defaults, maybe turn these into Kconfig options ? */
+#define DRAM_CLK_DEFAULT 312000000
+#define DRAM_ZQ_DEFAULT 0x78
+
+struct dram_sun6i_para {
+	u8 bus_width;
+	u8 chan;
+	u8 rank;
+	u8 rows;
+	u16 page_size;
+};
+
+/*
+ * Wait up to 1s for value to be set in given part of reg.
+ */
+static void await_completion(u32 *reg, u32 mask, u32 val)
+{
+	unsigned long tmo = timer_get_us() + 1000000;
+
+	while ((readl(reg) & mask) != val) {
+		if (timer_get_us() > tmo)
+			panic("Timeout initialising DRAM\n");
+	}
+}
+
+static void mctl_sys_init(void)
+{
+	struct sunxi_ccm_reg * const ccm =
+		(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
+	const int dram_clk_div = 2;
+
+	clock_set_pll5(DRAM_CLK_DEFAULT * dram_clk_div);
+
+	clrsetbits_le32(&ccm->dram_clk_cfg, CCM_DRAMCLK_CFG_DIV0_MASK,
+		CCM_DRAMCLK_CFG_DIV0(dram_clk_div) | CCM_DRAMCLK_CFG_RST |
+		CCM_DRAMCLK_CFG_UPD);
+	await_completion(&ccm->dram_clk_cfg, CCM_DRAMCLK_CFG_UPD, 0);
+
+	writel(MDFS_CLK_DEFAULT, &ccm->mdfs_clk_cfg);
+
+	/* deassert mctl reset */
+	setbits_le32(&ccm->ahb_reset0_cfg, 1 << AHB_RESET_OFFSET_MCTL);
+
+	/* enable mctl clock */
+	setbits_le32(&ccm->ahb_gate0, 1 << AHB_GATE_OFFSET_MCTL);
+}
+
+static void mctl_dll_init(int ch_index, struct dram_sun6i_para *para)
+{
+	struct sunxi_mctl_phy_reg *mctl_phy;
+
+	if (ch_index == 0)
+		mctl_phy = (struct sunxi_mctl_phy_reg *)SUNXI_DRAM_PHY0_BASE;
+	else
+		mctl_phy = (struct sunxi_mctl_phy_reg *)SUNXI_DRAM_PHY1_BASE;
+
+	/* disable + reset dlls */
+	writel(MCTL_DLLCR_DISABLE, &mctl_phy->acdllcr);
+	writel(MCTL_DLLCR_DISABLE, &mctl_phy->dx0dllcr);
+	writel(MCTL_DLLCR_DISABLE, &mctl_phy->dx1dllcr);
+	if (para->bus_width == 32) {
+		writel(MCTL_DLLCR_DISABLE, &mctl_phy->dx2dllcr);
+		writel(MCTL_DLLCR_DISABLE, &mctl_phy->dx3dllcr);
+	}
+	udelay(2);
+
+	/* enable + reset dlls */
+	writel(0, &mctl_phy->acdllcr);
+	writel(0, &mctl_phy->dx0dllcr);
+	writel(0, &mctl_phy->dx1dllcr);
+	if (para->bus_width == 32) {
+		writel(0, &mctl_phy->dx2dllcr);
+		writel(0, &mctl_phy->dx3dllcr);
+	}
+	udelay(22);
+
+	/* enable and release reset of dlls */
+	writel(MCTL_DLLCR_NRESET, &mctl_phy->acdllcr);
+	writel(MCTL_DLLCR_NRESET, &mctl_phy->dx0dllcr);
+	writel(MCTL_DLLCR_NRESET, &mctl_phy->dx1dllcr);
+	if (para->bus_width == 32) {
+		writel(MCTL_DLLCR_NRESET, &mctl_phy->dx2dllcr);
+		writel(MCTL_DLLCR_NRESET, &mctl_phy->dx3dllcr);
+	}
+	udelay(22);
+}
+
+static bool mctl_rank_detect(u32 *gsr0, int rank)
+{
+	const u32 done = MCTL_DX_GSR0_RANK0_TRAIN_DONE << rank;
+	const u32 err = MCTL_DX_GSR0_RANK0_TRAIN_ERR << rank;
+
+	await_completion(gsr0, done, done);
+	await_completion(gsr0 + 0x10, done, done);
+
+	return !(readl(gsr0) & err) && !(readl(gsr0 + 0x10) & err);
+}
+
+static void mctl_channel_init(int ch_index, struct dram_sun6i_para *para)
+{
+	struct sunxi_mctl_com_reg * const mctl_com =
+		(struct sunxi_mctl_com_reg *)SUNXI_DRAM_COM_BASE;
+	struct sunxi_mctl_ctl_reg *mctl_ctl;
+	struct sunxi_mctl_phy_reg *mctl_phy;
+
+	if (ch_index == 0) {
+		mctl_ctl = (struct sunxi_mctl_ctl_reg *)SUNXI_DRAM_CTL0_BASE;
+		mctl_phy = (struct sunxi_mctl_phy_reg *)SUNXI_DRAM_PHY0_BASE;
+	} else {
+		mctl_ctl = (struct sunxi_mctl_ctl_reg *)SUNXI_DRAM_CTL1_BASE;
+		mctl_phy = (struct sunxi_mctl_phy_reg *)SUNXI_DRAM_PHY1_BASE;
+	}
+
+	writel(MCTL_MCMD_NOP, &mctl_ctl->mcmd);
+	await_completion(&mctl_ctl->mcmd, MCTL_MCMD_BUSY, 0);
+
+	/* PHY initialization */
+	writel(MCTL_PGCR, &mctl_phy->pgcr);
+	writel(MCTL_MR0, &mctl_phy->mr0);
+	writel(MCTL_MR1, &mctl_phy->mr1);
+	writel(MCTL_MR2, &mctl_phy->mr2);
+	writel(MCTL_MR3, &mctl_phy->mr3);
+
+	writel((MCTL_TITMSRST << 18) | (MCTL_TDLLLOCK << 6) | MCTL_TDLLSRST,
+	       &mctl_phy->ptr0);
+	/* Unknown magic performed by boot0 */
+	if ((readl(SUNXI_RTC_BASE + 0x20c) & 3) == 2)
+		setbits_le32(&mctl_phy->ptr0, 1 << 18);
+
+	writel((MCTL_TDINIT1 << 19) | MCTL_TDINIT0, &mctl_phy->ptr1);
+	writel((MCTL_TDINIT3 << 17) | MCTL_TDINIT2, &mctl_phy->ptr2);
+
+	writel((MCTL_TCCD << 31) | (MCTL_TRC << 25) | (MCTL_TRRD << 21) |
+	       (MCTL_TRAS << 16) | (MCTL_TRCD << 12) | (MCTL_TRP << 8) |
+	       (MCTL_TWTR << 5) | (MCTL_TRTP << 2) | (MCTL_TMRD << 0),
+	       &mctl_phy->dtpr0);
+
+	writel((MCTL_TDQSCKMAX << 27) | (MCTL_TDQSCK << 24) |
+	       (MCTL_TRFC << 16) | (MCTL_TRTODT << 11) |
+	       ((MCTL_TMOD - 12) << 9) | (MCTL_TFAW << 3) | (0 << 2) |
+	       (MCTL_TAOND << 0), &mctl_phy->dtpr1);
+
+	writel((MCTL_TDLLK << 19) | (MCTL_TCKE << 15) | (MCTL_TXPDLL << 10) |
+	       (MCTL_TEXSR << 0), &mctl_phy->dtpr2);
+
+	writel(1, &mctl_ctl->dfitphyupdtype0);
+	writel(MCTL_DCR_DDR3, &mctl_phy->dcr);
+	writel(MCTL_DSGCR, &mctl_phy->dsgcr);
+	writel(MCTL_DXCCR, &mctl_phy->dxccr);
+	writel(MCTL_DX_GCR | MCTL_DX_GCR_EN, &mctl_phy->dx0gcr);
+	writel(MCTL_DX_GCR | MCTL_DX_GCR_EN, &mctl_phy->dx1gcr);
+	writel(MCTL_DX_GCR | MCTL_DX_GCR_EN, &mctl_phy->dx2gcr);
+	writel(MCTL_DX_GCR | MCTL_DX_GCR_EN, &mctl_phy->dx3gcr);
+
+	await_completion(&mctl_phy->pgsr, 0x03, 0x03);
+
+	writel(DRAM_ZQ_DEFAULT, &mctl_phy->zq0cr1);
+
+	setbits_le32(&mctl_phy->pir, MCTL_PIR_CLEAR_STATUS);
+	writel(MCTL_PIR_STEP1, &mctl_phy->pir);
+	udelay(10);
+	await_completion(&mctl_phy->pgsr, 0x1f, 0x1f);
+
+	/* rank detect */
+	if (!mctl_rank_detect(&mctl_phy->dx0gsr0, 1)) {
+		para->rank = 1;
+		clrbits_le32(&mctl_phy->pgcr, MCTL_PGCR_RANK);
+	}
+
+	/*
+	 * channel detect, check channel 1 dx0 and dx1 have rank 0, if not
+	 * assume nothing is connected to channel 1.
+	 */
+	if (ch_index == 1 && !mctl_rank_detect(&mctl_phy->dx0gsr0, 0)) {
+		para->chan = 1;
+		clrbits_le32(&mctl_com->ccr, MCTL_CCR_CH1_CLK_EN);
+		return;
+	}
+
+	/* bus width detect, if dx2 and dx3 don't have rank 0, assume 16 bit */
+	if (!mctl_rank_detect(&mctl_phy->dx2gsr0, 0)) {
+		para->bus_width = 16;
+		para->page_size = 2048;
+		setbits_le32(&mctl_phy->dx2dllcr, MCTL_DLLCR_DISABLE);
+		setbits_le32(&mctl_phy->dx3dllcr, MCTL_DLLCR_DISABLE);
+		clrbits_le32(&mctl_phy->dx2gcr, MCTL_DX_GCR_EN);
+		clrbits_le32(&mctl_phy->dx3gcr, MCTL_DX_GCR_EN);
+	}
+
+	setbits_le32(&mctl_phy->pir, MCTL_PIR_CLEAR_STATUS);
+	writel(MCTL_PIR_STEP2, &mctl_phy->pir);
+	udelay(10);
+	await_completion(&mctl_phy->pgsr, 0x11, 0x11);
+
+	if (readl(&mctl_phy->pgsr) & MCTL_PGSR_TRAIN_ERR_MASK)
+		panic("Training error initialising DRAM\n");
+
+	/* Move to configure state */
+	writel(MCTL_SCTL_CONFIG, &mctl_ctl->sctl);
+	await_completion(&mctl_ctl->sstat, 0x07, 0x01);
+
+	/* Set number of clks per micro-second */
+	writel(DRAM_CLK_DEFAULT / 1000000, &mctl_ctl->togcnt1u);
+	/* Set number of clks per 100 nano-seconds */
+	writel(DRAM_CLK_DEFAULT / 10000000, &mctl_ctl->togcnt100n);
+	/* Set memory timing registers */
+	writel(MCTL_TREFI, &mctl_ctl->trefi);
+	writel(MCTL_TMRD, &mctl_ctl->tmrd);
+	writel(MCTL_TRFC, &mctl_ctl->trfc);
+	writel((MCTL_TPREA << 16) | MCTL_TRP, &mctl_ctl->trp);
+	writel(MCTL_TRTW, &mctl_ctl->trtw);
+	writel(MCTL_TAL, &mctl_ctl->tal);
+	writel(MCTL_TCL, &mctl_ctl->tcl);
+	writel(MCTL_TCWL, &mctl_ctl->tcwl);
+	writel(MCTL_TRAS, &mctl_ctl->tras);
+	writel(MCTL_TRC, &mctl_ctl->trc);
+	writel(MCTL_TRCD, &mctl_ctl->trcd);
+	writel(MCTL_TRRD, &mctl_ctl->trrd);
+	writel(MCTL_TRTP, &mctl_ctl->trtp);
+	writel(MCTL_TWR, &mctl_ctl->twr);
+	writel(MCTL_TWTR, &mctl_ctl->twtr);
+	writel(MCTL_TEXSR, &mctl_ctl->texsr);
+	writel(MCTL_TXP, &mctl_ctl->txp);
+	writel(MCTL_TXPDLL, &mctl_ctl->txpdll);
+	writel(MCTL_TZQCS, &mctl_ctl->tzqcs);
+	writel(MCTL_TZQCSI, &mctl_ctl->tzqcsi);
+	writel(MCTL_TDQS, &mctl_ctl->tdqs);
+	writel(MCTL_TCKSRE, &mctl_ctl->tcksre);
+	writel(MCTL_TCKSRX, &mctl_ctl->tcksrx);
+	writel(MCTL_TCKE, &mctl_ctl->tcke);
+	writel(MCTL_TMOD, &mctl_ctl->tmod);
+	writel(MCTL_TRSTL, &mctl_ctl->trstl);
+	writel(MCTL_TZQCL, &mctl_ctl->tzqcl);
+	writel(MCTL_TMRR, &mctl_ctl->tmrr);
+	writel(MCTL_TCKESR, &mctl_ctl->tckesr);
+	writel(MCTL_TDPD, &mctl_ctl->tdpd);
+
+	/* Unknown magic performed by boot0 */
+	setbits_le32(&mctl_ctl->dfiodtcfg, 1 << 3);
+	clrbits_le32(&mctl_ctl->dfiodtcfg1, 0x1f);
+
+	/* Select 16/32-bits mode for MCTL */
+	if (para->bus_width == 16)
+		setbits_le32(&mctl_ctl->ppcfg, 1);
+
+	/* Set DFI timing registers */
+	writel(MCTL_TCWL, &mctl_ctl->dfitphywrl);
+	writel(MCTL_TCL - 1, &mctl_ctl->dfitrdden);
+	writel(MCTL_DFITPHYRDL, &mctl_ctl->dfitphyrdl);
+	writel(MCTL_DFISTCFG0, &mctl_ctl->dfistcfg0);
+
+	writel(MCTL_MCFG_DDR3, &mctl_ctl->mcfg);
+
+	/* DFI update configuration register */
+	writel(MCTL_DFIUPDCFG_UPD, &mctl_ctl->dfiupdcfg);
+
+	/* Move to access state */
+	writel(MCTL_SCTL_ACCESS, &mctl_ctl->sctl);
+	await_completion(&mctl_ctl->sstat, 0x07, 0x03);
+}
+
+static void mctl_com_init(struct dram_sun6i_para *para)
+{
+	struct sunxi_mctl_com_reg * const mctl_com =
+		(struct sunxi_mctl_com_reg *)SUNXI_DRAM_COM_BASE;
+	struct sunxi_mctl_phy_reg * const mctl_phy1 =
+		(struct sunxi_mctl_phy_reg *)SUNXI_DRAM_PHY1_BASE;
+	struct sunxi_prcm_reg * const prcm =
+		(struct sunxi_prcm_reg *)SUNXI_PRCM_BASE;
+
+	writel(MCTL_CR_UNKNOWN | MCTL_CR_CHANNEL(para->chan) | MCTL_CR_DDR3 |
+	       ((para->bus_width == 32) ? MCTL_CR_BUSW32 : MCTL_CR_BUSW16) |
+	       MCTL_CR_PAGE_SIZE(para->page_size) | MCTL_CR_ROW(para->rows) |
+	       MCTL_CR_BANK(1) | MCTL_CR_RANK(para->rank), &mctl_com->cr);
+
+	/* Unknown magic performed by boot0 */
+	setbits_le32(&mctl_com->dbgcr, (1 << 6));
+
+	if (para->chan == 1) {
+		/* Shutdown channel 1 */
+		setbits_le32(&mctl_phy1->aciocr, MCTL_ACIOCR_DISABLE);
+		setbits_le32(&mctl_phy1->dxccr, MCTL_DXCCR_DISABLE);
+		clrbits_le32(&mctl_phy1->dsgcr, MCTL_DSGCR_ENABLE);
+		/*
+		 * CH0 ?? this is what boot0 does. Leave as is until we can
+		 * confirm this.
+		 */
+		setbits_le32(&prcm->vdd_sys_pwroff,
+			     PRCM_VDD_SYS_DRAM_CH0_PAD_HOLD_PWROFF);
+	}
+}
+
+static void mctl_port_cfg(void)
+{
+	struct sunxi_mctl_com_reg * const mctl_com =
+		(struct sunxi_mctl_com_reg *)SUNXI_DRAM_COM_BASE;
+	struct sunxi_ccm_reg * const ccm =
+		(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
+
+	/* enable DRAM AXI clock for CPU access */
+	setbits_le32(&ccm->axi_gate, 1 << AXI_GATE_OFFSET_DRAM);
+
+	/* Bunch of magic writes performed by boot0 */
+	writel(0x00400302, &mctl_com->rmcr[0]);
+	writel(0x01000307, &mctl_com->rmcr[1]);
+	writel(0x00400302, &mctl_com->rmcr[2]);
+	writel(0x01000307, &mctl_com->rmcr[3]);
+	writel(0x01000307, &mctl_com->rmcr[4]);
+	writel(0x01000303, &mctl_com->rmcr[6]);
+	writel(0x01000303, &mctl_com->mmcr[0]);
+	writel(0x00400310, &mctl_com->mmcr[1]);
+	writel(0x01000307, &mctl_com->mmcr[2]);
+	writel(0x01000303, &mctl_com->mmcr[3]);
+	writel(0x01800303, &mctl_com->mmcr[4]);
+	writel(0x01800303, &mctl_com->mmcr[5]);
+	writel(0x01800303, &mctl_com->mmcr[6]);
+	writel(0x01800303, &mctl_com->mmcr[7]);
+	writel(0x01000303, &mctl_com->mmcr[8]);
+	writel(0x00000002, &mctl_com->mmcr[15]);
+	writel(0x00000310, &mctl_com->mbagcr[0]);
+	writel(0x00400310, &mctl_com->mbagcr[1]);
+	writel(0x00400310, &mctl_com->mbagcr[2]);
+	writel(0x00000307, &mctl_com->mbagcr[3]);
+	writel(0x00000317, &mctl_com->mbagcr[4]);
+	writel(0x00000307, &mctl_com->mbagcr[5]);
+}
+
+static bool mctl_mem_matches(u32 offset)
+{
+	const int match_count = 64;
+	int i, matches = 0;
+
+	for (i = 0; i < match_count; i++) {
+		if (readl(CONFIG_SYS_SDRAM_BASE + i * 4) ==
+		    readl(CONFIG_SYS_SDRAM_BASE + offset + i * 4))
+			matches++;
+	}
+
+	return matches == match_count;
+}
+
+unsigned long sunxi_dram_init(void)
+{
+	struct sunxi_mctl_com_reg * const mctl_com =
+		(struct sunxi_mctl_com_reg *)SUNXI_DRAM_COM_BASE;
+	u32 offset;
+	int bank, bus, columns;
+
+	/* Set initial parameters, these get modified by the autodetect code */
+	struct dram_sun6i_para para = {
+		.bus_width = 32,
+		.chan = 2,
+		.rank = 2,
+		.page_size = 4096,
+		.rows = 16,
+	};
+
+	mctl_sys_init();
+
+	mctl_dll_init(0, &para);
+	mctl_dll_init(1, &para);
+
+	setbits_le32(&mctl_com->ccr,
+		     MCTL_CCR_MASTER_CLK_EN |
+		     MCTL_CCR_CH0_CLK_EN |
+		     MCTL_CCR_CH1_CLK_EN);
+
+	mctl_channel_init(0, &para);
+	mctl_channel_init(1, &para);
+	mctl_com_init(&para);
+	mctl_port_cfg();
+
+	/*
+	 * Change to 1 ch / sequence / 8192 byte pages / 16 rows /
+	 * 8 bit banks / 1 rank mode.
+	 */
+	clrsetbits_le32(&mctl_com->cr,
+		MCTL_CR_CHANNEL_MASK | MCTL_CR_PAGE_SIZE_MASK |
+		    MCTL_CR_ROW_MASK | MCTL_CR_BANK_MASK | MCTL_CR_RANK_MASK,
+		MCTL_CR_CHANNEL(1) | MCTL_CR_SEQUENCE |
+		    MCTL_CR_PAGE_SIZE(8192) | MCTL_CR_ROW(16) |
+		    MCTL_CR_BANK(1) | MCTL_CR_RANK(1));
+
+	/* Detect and set page size */
+	for (columns = 7; columns < 20; columns++) {
+		if (mctl_mem_matches(1 << columns))
+			break;
+	}
+	bus = (para.bus_width == 32) ? 2 : 1;
+	columns -= bus;
+	para.page_size = (1 << columns) * (bus << 1);
+	clrsetbits_le32(&mctl_com->cr, MCTL_CR_PAGE_SIZE_MASK,
+			MCTL_CR_PAGE_SIZE(para.page_size));
+
+	/* Detect and set rows */
+	for (para.rows = 11; para.rows < 16; para.rows++) {
+		offset = 1 << (para.rows + columns + bus);
+		if (mctl_mem_matches(offset))
+			break;
+	}
+	clrsetbits_le32(&mctl_com->cr, MCTL_CR_ROW_MASK,
+			MCTL_CR_ROW(para.rows));
+
+	/* Detect bank size */
+	offset = 1 << (para.rows + columns + bus + 2);
+	bank = mctl_mem_matches(offset) ? 0 : 1;
+
+	/* Restore interleave, chan and rank values, set bank size */
+	clrsetbits_le32(&mctl_com->cr,
+			MCTL_CR_CHANNEL_MASK | MCTL_CR_SEQUENCE |
+			    MCTL_CR_BANK_MASK | MCTL_CR_RANK_MASK,
+			MCTL_CR_CHANNEL(para.chan) | MCTL_CR_BANK(bank) |
+			    MCTL_CR_RANK(para.rank));
+
+	return 1 << (para.rank + para.rows + bank + columns + para.chan + bus);
+}