ddr: Add DDR driver for iMX8ULP

Add iMX8ULP DDR initialization driver which loads the DDR timing
parameters and executes the training procedure.

When enabling IMX8ULP_DRAM_PHY_PLL_BYPASS, using PHY PLL bypass mode
to do DDR init
Signed-off-by: NYe Li <ye.li@nxp.com>

drivers/Makefile

@@ -45,6 +45,7 @@ obj-$(CONFIG_ARMADA_38X) += ddr/marvell/a38x/
 obj-$(CONFIG_ARMADA_XP) += ddr/marvell/axp/
 obj-$(CONFIG_$(SPL_)ALTERA_SDRAM) += ddr/altera/
 obj-$(CONFIG_ARCH_IMX8M) += ddr/imx/imx8m/
+obj-$(CONFIG_IMX8ULP_DRAM) += ddr/imx/imx8ulp/
 obj-$(CONFIG_SPL_POWER) += power/ power/pmic/
 obj-$(CONFIG_SPL_POWER) += power/regulator/
 obj-$(CONFIG_SPL_POWER_DOMAIN) += power/domain/

drivers/ddr/imx/Kconfig

 source "drivers/ddr/imx/imx8m/Kconfig"
+source "drivers/ddr/imx/imx8ulp/Kconfig"

drivers/ddr/imx/imx8ulp/Kconfig

+menu "i.MX8ULP DDR controllers"
+	depends on ARCH_IMX8ULP
+
+config IMX8ULP_DRAM
+	bool "imx8m dram"
+
+config IMX8ULP_DRAM_PHY_PLL_BYPASS
+	bool "Enable the DDR PHY PLL bypass mode, so PHY clock is from DDR_CLK "
+	depends on IMX8ULP_DRAM
+
+endmenu

drivers/ddr/imx/imx8ulp/Makefile

+#
+# Copyright 2021 NXP
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+ifdef CONFIG_SPL_BUILD
+obj-$(CONFIG_IMX8ULP_DRAM) += ddr_init.o
+endif

drivers/ddr/imx/imx8ulp/ddr_init.c

+// SPDX-License-Identifier: GPL-2.0+ OR MIT
+/*
+ * Copyright 2021 NXP
+ */
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/ddr.h>
+#include <asm/arch/imx-regs.h>
+
+#define DENALI_CTL_00		(DDR_CTL_BASE_ADDR + 4 * 0)
+#define CTL_START		0x1
+
+#define DENALI_CTL_03		(DDR_CTL_BASE_ADDR + 4 * 3)
+#define DENALI_CTL_197		(DDR_CTL_BASE_ADDR + 4 * 197)
+#define DENALI_CTL_250		(DDR_CTL_BASE_ADDR + 4 * 250)
+#define DENALI_CTL_251		(DDR_CTL_BASE_ADDR + 4 * 251)
+#define DENALI_CTL_266		(DDR_CTL_BASE_ADDR + 4 * 266)
+#define DFI_INIT_COMPLETE	0x2
+
+#define DENALI_CTL_614		(DDR_CTL_BASE_ADDR + 4 * 614)
+#define DENALI_CTL_615		(DDR_CTL_BASE_ADDR + 4 * 615)
+
+#define DENALI_PI_00		(DDR_PI_BASE_ADDR + 4 * 0)
+#define PI_START		0x1
+
+#define DENALI_PI_04		(DDR_PI_BASE_ADDR + 4 * 4)
+#define DENALI_PI_11		(DDR_PI_BASE_ADDR + 4 * 11)
+#define DENALI_PI_12		(DDR_PI_BASE_ADDR + 4 * 12)
+#define DENALI_CTL_23		(DDR_CTL_BASE_ADDR + 4 * 23)
+#define DENALI_CTL_25		(DDR_CTL_BASE_ADDR + 4 * 25)
+
+#define DENALI_PHY_1624		(DDR_PHY_BASE_ADDR + 4 * 1624)
+#define DENALI_PHY_1537		(DDR_PHY_BASE_ADDR + 4 * 1537)
+#define PHY_FREQ_SEL_MULTICAST_EN(X)	((X) << 8)
+#define PHY_FREQ_SEL_INDEX(X)		((X) << 16)
+
+#define DENALI_PHY_1547		(DDR_PHY_BASE_ADDR + 4 * 1547)
+#define DENALI_PHY_1555		(DDR_PHY_BASE_ADDR + 4 * 1555)
+#define DENALI_PHY_1564		(DDR_PHY_BASE_ADDR + 4 * 1564)
+#define DENALI_PHY_1565		(DDR_PHY_BASE_ADDR + 4 * 1565)
+
+static void ddr_enable_pll_bypass(void)
+{
+	u32 reg_val;
+
+	/* PI_INIT_LVL_EN=0x0  (DENALI_PI_04) */
+	reg_val = readl(DENALI_PI_04) & ~0x1;
+	writel(reg_val, DENALI_PI_04);
+
+	/* PI_FREQ_MAP=0x1  (DENALI_PI_12) */
+	writel(0x1, DENALI_PI_12);
+
+	/* PI_INIT_WORK_FREQ=0x0  (DENALI_PI_11) */
+	reg_val = readl(DENALI_PI_11) & ~(0x1f << 8);
+	writel(reg_val, DENALI_PI_11);
+
+	/* DFIBUS_FREQ_INIT=0x0  (DENALI_CTL_23) */
+	reg_val = readl(DENALI_CTL_23) & ~(0x3 << 24);
+	writel(reg_val, DENALI_CTL_23);
+
+	/* PHY_LP4_BOOT_DISABLE=0x0 (DENALI_PHY_1547) */
+	reg_val = readl(DENALI_PHY_1547) & ~(0x1 << 8);
+	writel(reg_val, DENALI_PHY_1547);
+
+	/* PHY_PLL_BYPASS=0x1 (DENALI_PHY_1624) */
+	reg_val = readl(DENALI_PHY_1624) | 0x1;
+	writel(reg_val, DENALI_PHY_1624);
+
+	/* PHY_LP4_BOOT_PLL_BYPASS to 0x1 (DENALI_PHY_1555) */
+	reg_val = readl(DENALI_PHY_1555) | 0x1;
+	writel(reg_val, DENALI_PHY_1555);
+
+	/* FREQ_CHANGE_TYPE_F0 = 0x0/FREQ_CHANGE_TYPE_F1 = 0x1/FREQ_CHANGE_TYPE_F2 = 0x2 */
+	reg_val = 0x020100;
+	writel(reg_val, DENALI_CTL_25);
+}
+
+int ddr_calibration(unsigned int fsp_table[3])
+{
+	u32 reg_val;
+	u32 int_status_init, phy_freq_req, phy_freq_type;
+	u32 lock_0, lock_1, lock_2;
+	u32 freq_chg_pt, freq_chg_cnt;
+
+	if (IS_ENABLED(CONFIG_IMX8ULP_DRAM_PHY_PLL_BYPASS)) {
+		ddr_enable_pll_bypass();
+		freq_chg_cnt = 0;
+		freq_chg_pt = 0;
+	} else {
+		reg_val = readl(DENALI_CTL_250);
+		if (((reg_val >> 16) & 0x3) == 1)
+			freq_chg_cnt = 2;
+		else
+			freq_chg_cnt = 3;
+
+		reg_val = readl(DENALI_PI_12);
+		if (reg_val == 0x3) {
+			freq_chg_pt = 1;
+		} else if (reg_val == 0x7) {
+			freq_chg_pt = 2;
+		} else {
+			printf("frequency map(0x%x) is wrong, please check!\r\n", reg_val);
+			return -1;
+		}
+	}
+
+	/* Assert PI_START parameter and then assert START parameter in Controller. */
+	reg_val = readl(DENALI_PI_00) | PI_START;
+	writel(reg_val, DENALI_PI_00);
+
+	reg_val = readl(DENALI_CTL_00) | CTL_START;
+	writel(reg_val, DENALI_CTL_00);
+
+	/* Poll for init_done_bit in Controller interrupt status register (INT_STATUS_INIT) */
+	do {
+		if (!freq_chg_cnt) {
+			int_status_init = (readl(DENALI_CTL_266) >> 8) & 0xff;
+			/* DDR subsystem is ready for traffic. */
+			if (int_status_init & DFI_INIT_COMPLETE) {
+				debug("complete\n");
+				break;
+			}
+		}
+
+		/*
+		 * During leveling, PHY will request for freq change and SoC clock logic
+		 * should provide requested frequency
+		 * Polling SIM LPDDR_CTRL2 Bit phy_freq_chg_req until be 1'b1
+		 */
+		reg_val = readl(AVD_SIM_LPDDR_CTRL2);
+		phy_freq_req = (reg_val >> 7) & 0x1;
+
+		if (phy_freq_req) {
+			phy_freq_type = reg_val & 0x1F;
+			if (phy_freq_type == 0x00) {
+				debug("Poll for freq_chg_req on SIM register and change to F0 frequency.\n");
+				set_ddr_clk(fsp_table[phy_freq_type] >> 1);
+
+				/* Write 1'b1 at LPDDR_CTRL2 bit phy_freq_cfg_ack */
+				reg_val = readl(AVD_SIM_LPDDR_CTRL2);
+				writel(reg_val | (0x1 << 6), AVD_SIM_LPDDR_CTRL2);
+			} else if (phy_freq_type == 0x01) {
+				debug("Poll for freq_chg_req on SIM register and change to F1 frequency.\n");
+				set_ddr_clk(fsp_table[phy_freq_type] >> 1);
+
+				/* Write 1'b1 at LPDDR_CTRL2 bit phy_freq_cfg_ack */
+				reg_val = readl(AVD_SIM_LPDDR_CTRL2);
+				writel(reg_val | (0x1 << 6), AVD_SIM_LPDDR_CTRL2);
+				if (freq_chg_pt == 1)
+					freq_chg_cnt--;
+			} else if (phy_freq_type == 0x02) {
+				debug("Poll for freq_chg_req on SIM register and change to F2 frequency.\n");
+				set_ddr_clk(fsp_table[phy_freq_type] >> 1);
+
+				/* Write 1'b1 at LPDDR_CTRL2 bit phy_freq_cfg_ack */
+				reg_val = readl(AVD_SIM_LPDDR_CTRL2);
+				writel(reg_val | (0x1 << 6), AVD_SIM_LPDDR_CTRL2);
+				if (freq_chg_pt == 2)
+					freq_chg_cnt--;
+			}
+			reg_val = readl(AVD_SIM_LPDDR_CTRL2);
+		}
+	} while (1);
+
+	/* Check PLL lock status */
+	lock_0 = readl(DENALI_PHY_1564) & 0xffff;
+	lock_1 = (readl(DENALI_PHY_1564) >> 16) & 0xffff;
+	lock_2 = readl(DENALI_PHY_1565) & 0xffff;
+
+	if ((lock_0 & 0x3) != 0x3 || (lock_1 & 0x3) != 0x3 || (lock_2 & 0x3) != 0x3) {
+		debug("De-Skew PLL failed to lock\n");
+		debug("lock_0=0x%x, lock_1=0x%x, lock_2=0x%x\n", lock_0, lock_1, lock_2);
+		return -1;
+	}
+
+	debug("De-Skew PLL is locked and ready\n");
+	return 0;
+}
+
+int ddr_init(struct dram_timing_info2 *dram_timing)
+{
+	int i;
+
+	if (IS_ENABLED(CONFIG_IMX8ULP_DRAM_PHY_PLL_BYPASS)) {
+		/* Use PLL bypass for boot freq */
+		/* Since PLL can't generate the double freq, Need ddr clock to generate it. */
+		set_ddr_clk(dram_timing->fsp_table[0]); /* Set to boot freq */
+		setbits_le32(AVD_SIM_BASE_ADDR, 0x1); /* SIM_DDR_CTRL_DIV2_EN */
+	} else {
+		set_ddr_clk(dram_timing->fsp_table[0] >> 1); /* Set to boot freq */
+		clrbits_le32(AVD_SIM_BASE_ADDR, 0x1); /* SIM_DDR_CTRL_DIV2_EN */
+	}
+
+	/* Initialize CTL registers */
+	for (i = 0; i < dram_timing->ctl_cfg_num; i++)
+		writel(dram_timing->ctl_cfg[i].val, (ulong)dram_timing->ctl_cfg[i].reg);
+
+	/* Initialize PI registers */
+	for (i = 0; i < dram_timing->pi_cfg_num; i++)
+		writel(dram_timing->pi_cfg[i].val, (ulong)dram_timing->pi_cfg[i].reg);
+
+	/* Write PHY regiters for all 3 frequency points (48Mhz/384Mhz/528Mhz): f1_index=0 */
+	writel(PHY_FREQ_SEL_MULTICAST_EN(1) | PHY_FREQ_SEL_INDEX(0), DENALI_PHY_1537);
+	for (i = 0; i < dram_timing->phy_f1_cfg_num; i++)
+		writel(dram_timing->phy_f1_cfg[i].val, (ulong)dram_timing->phy_f1_cfg[i].reg);
+
+	/* Write PHY regiters for freqency point 2 (528Mhz): f2_index=1 */
+	writel(PHY_FREQ_SEL_MULTICAST_EN(0) | PHY_FREQ_SEL_INDEX(1), DENALI_PHY_1537);
+	for (i = 0; i < dram_timing->phy_f2_cfg_num; i++)
+		writel(dram_timing->phy_f2_cfg[i].val, (ulong)dram_timing->phy_f2_cfg[i].reg);
+
+	/* Re-enable MULTICAST mode */
+	writel(PHY_FREQ_SEL_MULTICAST_EN(1) | PHY_FREQ_SEL_INDEX(0), DENALI_PHY_1537);
+
+	return ddr_calibration(dram_timing->fsp_table);
+}