sifive: fu540: add ddr driver

Add driver for fu540 to support ddr initialization in SPL.
This driver is based on FSBL
(https://github.com/sifive/freedom-u540-c000-bootloader.git)

Signed-off-by: Pragnesh Patel <pragnesh.patel@sifive.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>

board/sifive/fu540/Kconfig

@@ -19,6 +19,8 @@ config SYS_TEXT_BASE
 config BOARD_SPECIFIC_OPTIONS # dummy
 	def_bool y
 	select GENERIC_RISCV
+	select RAM
+	select SPL_RAM if SPL
 	imply CMD_DHCP
 	imply CMD_EXT2
 	imply CMD_EXT4

drivers/ram/Kconfig

@@ -74,4 +74,5 @@ config IMXRT_SDRAM
 	  This driver is for the sdram memory interface with the SEMC.
 
 source "drivers/ram/rockchip/Kconfig"
+source "drivers/ram/sifive/Kconfig"
 source "drivers/ram/stm32mp1/Kconfig"

drivers/ram/Makefile

@@ -17,3 +17,5 @@ obj-$(CONFIG_ARCH_MEDIATEK) += mediatek/
 obj-$(CONFIG_K3_J721E_DDRSS) += k3-j721e/
 
 obj-$(CONFIG_IMXRT_SDRAM) += imxrt_sdram.o
+
+obj-$(CONFIG_RAM_SIFIVE) += sifive/

drivers/ram/sifive/Kconfig

@@ -0,0 +1,13 @@
+config RAM_SIFIVE
+	bool "Ram drivers support for SiFive SoCs"
+	depends on RAM && RISCV
+	default y
+	help
+	  This enables support for ram drivers of SiFive SoCs.
+
+config SIFIVE_FU540_DDR
+	bool "SiFive FU540 DDR driver"
+	depends on RAM_SIFIVE
+	default y if TARGET_SIFIVE_FU540
+	help
+	  This enables DDR support for the platforms based on SiFive FU540 SoC.

drivers/ram/sifive/Makefile

@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (c) 2020 SiFive, Inc
+#
+
+obj-$(CONFIG_SIFIVE_FU540_DDR) += fu540_ddr.o

drivers/ram/sifive/fu540_ddr.c

@@ -0,0 +1,410 @@
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+/*
+ * (C) Copyright 2020 SiFive, Inc.
+ *
+ * Authors:
+ *   Pragnesh Patel <pragnesh.patel@sifive.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <init.h>
+#include <ram.h>
+#include <regmap.h>
+#include <syscon.h>
+#include <asm/io.h>
+#include <clk.h>
+#include <wait_bit.h>
+#include <linux/bitops.h>
+
+#define DENALI_CTL_0	0
+#define DENALI_CTL_21	21
+#define DENALI_CTL_120	120
+#define DENALI_CTL_132	132
+#define DENALI_CTL_136	136
+#define DENALI_CTL_170	170
+#define DENALI_CTL_181	181
+#define DENALI_CTL_182	182
+#define DENALI_CTL_184	184
+#define DENALI_CTL_208	208
+#define DENALI_CTL_209	209
+#define DENALI_CTL_210	210
+#define DENALI_CTL_212	212
+#define DENALI_CTL_214	214
+#define DENALI_CTL_216	216
+#define DENALI_CTL_224	224
+#define DENALI_CTL_225	225
+#define DENALI_CTL_260	260
+
+#define DENALI_PHY_1152	1152
+#define DENALI_PHY_1214	1214
+
+#define PAYLOAD_DEST	0x80000000
+#define DDR_MEM_SIZE	(8UL * 1024UL * 1024UL * 1024UL)
+
+#define DRAM_CLASS_OFFSET			8
+#define DRAM_CLASS_DDR4				0xA
+#define OPTIMAL_RMODW_EN_OFFSET			0
+#define DISABLE_RD_INTERLEAVE_OFFSET		16
+#define OUT_OF_RANGE_OFFSET			1
+#define MULTIPLE_OUT_OF_RANGE_OFFSET		2
+#define PORT_COMMAND_CHANNEL_ERROR_OFFSET	7
+#define MC_INIT_COMPLETE_OFFSET			8
+#define LEVELING_OPERATION_COMPLETED_OFFSET	22
+#define DFI_PHY_WRLELV_MODE_OFFSET		24
+#define DFI_PHY_RDLVL_MODE_OFFSET		24
+#define DFI_PHY_RDLVL_GATE_MODE_OFFSET		0
+#define VREF_EN_OFFSET				24
+#define PORT_ADDR_PROTECTION_EN_OFFSET		0
+#define AXI0_ADDRESS_RANGE_ENABLE		8
+#define AXI0_RANGE_PROT_BITS_0_OFFSET		24
+#define RDLVL_EN_OFFSET				16
+#define RDLVL_GATE_EN_OFFSET			24
+#define WRLVL_EN_OFFSET				0
+
+#define PHY_RX_CAL_DQ0_0_OFFSET			0
+#define PHY_RX_CAL_DQ1_0_OFFSET			16
+
+struct fu540_ddrctl {
+	volatile u32 denali_ctl[265];
+};
+
+struct fu540_ddrphy {
+	volatile u32 denali_phy[1215];
+};
+
+/**
+ * struct fu540_ddr_info
+ *
+ * @dev                         : pointer for the device
+ * @info                        : UCLASS RAM information
+ * @ctl                         : DDR controller base address
+ * @phy                         : DDR PHY base address
+ * @ctrl                        : DDR control base address
+ * @physical_filter_ctrl        : DDR physical filter control base address
+ */
+struct fu540_ddr_info {
+	struct udevice *dev;
+	struct ram_info info;
+	struct fu540_ddrctl *ctl;
+	struct fu540_ddrphy *phy;
+	struct clk ddr_clk;
+	u32 *physical_filter_ctrl;
+};
+
+#if defined(CONFIG_SPL_BUILD)
+struct fu540_ddr_params {
+	struct fu540_ddrctl pctl_regs;
+	struct fu540_ddrphy phy_regs;
+};
+
+struct sifive_dmc_plat {
+	struct fu540_ddr_params ddr_params;
+};
+
+/*
+ * TODO : It can be possible to use common sdram_copy_to_reg() API
+ * n: Unit bytes
+ */
+static void sdram_copy_to_reg(volatile u32 *dest,
+			      volatile u32 *src, u32 n)
+{
+	int i;
+
+	for (i = 0; i < n / sizeof(u32); i++) {
+		writel(*src, dest);
+		src++;
+		dest++;
+	}
+}
+
+static void fu540_ddr_setup_range_protection(volatile u32 *ctl, u64 end_addr)
+{
+	u32 end_addr_16kblocks = ((end_addr >> 14) & 0x7FFFFF) - 1;
+
+	writel(0x0, DENALI_CTL_209 + ctl);
+	writel(end_addr_16kblocks, DENALI_CTL_210 + ctl);
+	writel(0x0, DENALI_CTL_212 + ctl);
+	writel(0x0, DENALI_CTL_214 + ctl);
+	writel(0x0, DENALI_CTL_216 + ctl);
+	setbits_le32(DENALI_CTL_224 + ctl,
+		     0x3 << AXI0_RANGE_PROT_BITS_0_OFFSET);
+	writel(0xFFFFFFFF, DENALI_CTL_225 + ctl);
+	setbits_le32(DENALI_CTL_208 + ctl, 0x1 << AXI0_ADDRESS_RANGE_ENABLE);
+	setbits_le32(DENALI_CTL_208 + ctl,
+		     0x1 << PORT_ADDR_PROTECTION_EN_OFFSET);
+}
+
+static void fu540_ddr_start(volatile u32 *ctl, u32 *physical_filter_ctrl,
+			    u64 ddr_end)
+{
+	volatile u64 *filterreg = (volatile u64 *)physical_filter_ctrl;
+
+	setbits_le32(DENALI_CTL_0 + ctl, 0x1);
+
+	wait_for_bit_le32((void *)ctl + DENALI_CTL_132,
+			  BIT(MC_INIT_COMPLETE_OFFSET), false, 100, false);
+
+	/* Disable the BusBlocker in front of the controller AXI slave ports */
+	filterreg[0] = 0x0f00000000000000UL | (ddr_end >> 2);
+}
+
+static void fu540_ddr_check_errata(u32 regbase, u32 updownreg)
+{
+	u64 fails     = 0;
+	u32 dq        = 0;
+	u32 down, up;
+	u8 failc0, failc1;
+	u32 phy_rx_cal_dqn_0_offset;
+
+	for (u32 bit = 0; bit < 2; bit++) {
+		if (bit == 0) {
+			phy_rx_cal_dqn_0_offset =
+				PHY_RX_CAL_DQ0_0_OFFSET;
+		} else {
+			phy_rx_cal_dqn_0_offset =
+				PHY_RX_CAL_DQ1_0_OFFSET;
+		}
+
+		down = (updownreg >>
+			phy_rx_cal_dqn_0_offset) & 0x3F;
+		up = (updownreg >>
+		      (phy_rx_cal_dqn_0_offset + 6)) &
+		      0x3F;
+
+		failc0 = ((down == 0) && (up == 0x3F));
+		failc1 = ((up == 0) && (down == 0x3F));
+
+		/* print error message on failure */
+		if (failc0 || failc1) {
+			if (fails == 0)
+				printf("DDR error in fixing up\n");
+
+			fails |= (1 << dq);
+
+			char slicelsc = '0';
+			char slicemsc = '0';
+
+			slicelsc += (dq % 10);
+			slicemsc += (dq / 10);
+			printf("S ");
+			printf("%c", slicemsc);
+			printf("%c", slicelsc);
+
+			if (failc0)
+				printf("U");
+			else
+				printf("D");
+
+			printf("\n");
+		}
+		dq++;
+	}
+}
+
+static u64 fu540_ddr_phy_fixup(volatile u32 *ddrphyreg)
+{
+	u32 slicebase = 0;
+
+	/* check errata condition */
+	for (u32 slice = 0; slice < 8; slice++) {
+		u32 regbase = slicebase + 34;
+
+		for (u32 reg = 0; reg < 4; reg++) {
+			u32 updownreg = readl(regbase + reg + ddrphyreg);
+
+			fu540_ddr_check_errata(regbase, updownreg);
+		}
+		slicebase += 128;
+	}
+
+	return(0);
+}
+
+static u32 fu540_ddr_get_dram_class(volatile u32 *ctl)
+{
+	u32 reg = readl(DENALI_CTL_0 + ctl);
+
+	return ((reg >> DRAM_CLASS_OFFSET) & 0xF);
+}
+
+static int fu540_ddr_setup(struct udevice *dev)
+{
+	struct fu540_ddr_info *priv = dev_get_priv(dev);
+	struct sifive_dmc_plat *plat = dev_get_platdata(dev);
+	struct fu540_ddr_params *params = &plat->ddr_params;
+	volatile u32 *denali_ctl =  priv->ctl->denali_ctl;
+	volatile u32 *denali_phy =  priv->phy->denali_phy;
+	const u64 ddr_size = DDR_MEM_SIZE;
+	const u64 ddr_end = PAYLOAD_DEST + ddr_size;
+	int ret, i;
+	u32 physet;
+
+	ret = dev_read_u32_array(dev, "sifive,ddr-params",
+				 (u32 *)&plat->ddr_params,
+				 sizeof(plat->ddr_params) / sizeof(u32));
+	if (ret) {
+		printf("%s: Cannot read sifive,ddr-params %d\n",
+		       __func__, ret);
+		return ret;
+	}
+
+	sdram_copy_to_reg(priv->ctl->denali_ctl,
+			  params->pctl_regs.denali_ctl,
+			  sizeof(struct fu540_ddrctl));
+
+	/* phy reset */
+	for (i = DENALI_PHY_1152; i <= DENALI_PHY_1214; i++) {
+		physet = params->phy_regs.denali_phy[i];
+		priv->phy->denali_phy[i] = physet;
+	}
+
+	for (i = 0; i < DENALI_PHY_1152; i++) {
+		physet = params->phy_regs.denali_phy[i];
+		priv->phy->denali_phy[i] = physet;
+	}
+
+	/* Disable read interleave DENALI_CTL_120 */
+	setbits_le32(DENALI_CTL_120 + denali_ctl,
+		     1 << DISABLE_RD_INTERLEAVE_OFFSET);
+
+	/* Disable optimal read/modify/write logic DENALI_CTL_21 */
+	clrbits_le32(DENALI_CTL_21 + denali_ctl, 1 << OPTIMAL_RMODW_EN_OFFSET);
+
+	/* Enable write Leveling DENALI_CTL_170 */
+	setbits_le32(DENALI_CTL_170 + denali_ctl, (1 << WRLVL_EN_OFFSET)
+		     | (1 << DFI_PHY_WRLELV_MODE_OFFSET));
+
+	/* Enable read leveling DENALI_CTL_181 and DENALI_CTL_260 */
+	setbits_le32(DENALI_CTL_181 + denali_ctl,
+		     1 << DFI_PHY_RDLVL_MODE_OFFSET);
+	setbits_le32(DENALI_CTL_260 + denali_ctl, 1 << RDLVL_EN_OFFSET);
+
+	/* Enable read leveling gate DENALI_CTL_260 and DENALI_CTL_182 */
+	setbits_le32(DENALI_CTL_260 + denali_ctl, 1 << RDLVL_GATE_EN_OFFSET);
+	setbits_le32(DENALI_CTL_182 + denali_ctl,
+		     1 << DFI_PHY_RDLVL_GATE_MODE_OFFSET);
+
+	if (fu540_ddr_get_dram_class(denali_ctl) == DRAM_CLASS_DDR4) {
+		/* Enable vref training DENALI_CTL_184 */
+		setbits_le32(DENALI_CTL_184 + denali_ctl, 1 << VREF_EN_OFFSET);
+	}
+
+	/* Mask off leveling completion interrupt DENALI_CTL_136 */
+	setbits_le32(DENALI_CTL_136 + denali_ctl,
+		     1 << LEVELING_OPERATION_COMPLETED_OFFSET);
+
+	/* Mask off MC init complete interrupt DENALI_CTL_136 */
+	setbits_le32(DENALI_CTL_136 + denali_ctl, 1 << MC_INIT_COMPLETE_OFFSET);
+
+	/* Mask off out of range interrupts DENALI_CTL_136 */
+	setbits_le32(DENALI_CTL_136 + denali_ctl, (1 << OUT_OF_RANGE_OFFSET)
+		     | (1 << MULTIPLE_OUT_OF_RANGE_OFFSET));
+
+	/* set up range protection */
+	fu540_ddr_setup_range_protection(denali_ctl, DDR_MEM_SIZE);
+
+	/* Mask off port command error interrupt DENALI_CTL_136 */
+	setbits_le32(DENALI_CTL_136 + denali_ctl,
+		     1 << PORT_COMMAND_CHANNEL_ERROR_OFFSET);
+
+	fu540_ddr_start(denali_ctl, priv->physical_filter_ctrl, ddr_end);
+
+	fu540_ddr_phy_fixup(denali_phy);
+
+	/* check size */
+	priv->info.size = get_ram_size((long *)priv->info.base,
+				       DDR_MEM_SIZE);
+
+	debug("%s : %lx\n", __func__, priv->info.size);
+
+	/* check memory access for all memory */
+	if (priv->info.size != DDR_MEM_SIZE) {
+		printf("DDR invalid size : 0x%lx, expected 0x%lx\n",
+		       priv->info.size, DDR_MEM_SIZE);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+#endif
+
+static int fu540_ddr_probe(struct udevice *dev)
+{
+	struct fu540_ddr_info *priv = dev_get_priv(dev);
+
+#if defined(CONFIG_SPL_BUILD)
+	struct regmap *map;
+	int ret;
+	u32 clock = 0;
+
+	debug("FU540 DDR probe\n");
+	priv->dev = dev;
+
+	ret = regmap_init_mem(dev_ofnode(dev), &map);
+	if (ret)
+		return ret;
+
+	ret = clk_get_by_index(dev, 0, &priv->ddr_clk);
+	if (ret) {
+		debug("clk get failed %d\n", ret);
+		return ret;
+	}
+
+	ret = dev_read_u32(dev, "clock-frequency", &clock);
+	if (ret) {
+		debug("clock-frequency not found in dt %d\n", ret);
+		return ret;
+	} else {
+		ret = clk_set_rate(&priv->ddr_clk, clock);
+		if (ret < 0) {
+			debug("Could not set DDR clock\n");
+			return ret;
+		}
+	}
+
+	ret = clk_enable(&priv->ddr_clk);
+	priv->ctl = regmap_get_range(map, 0);
+	priv->phy = regmap_get_range(map, 1);
+	priv->physical_filter_ctrl = regmap_get_range(map, 2);
+
+	priv->info.base = CONFIG_SYS_SDRAM_BASE;
+
+	priv->info.size = 0;
+	return fu540_ddr_setup(dev);
+#else
+	priv->info.base = CONFIG_SYS_SDRAM_BASE;
+	priv->info.size = DDR_MEM_SIZE;
+#endif
+	return 0;
+}
+
+static int fu540_ddr_get_info(struct udevice *dev, struct ram_info *info)
+{
+	struct fu540_ddr_info *priv = dev_get_priv(dev);
+
+	*info = priv->info;
+
+	return 0;
+}
+
+static struct ram_ops fu540_ddr_ops = {
+	.get_info = fu540_ddr_get_info,
+};
+
+static const struct udevice_id fu540_ddr_ids[] = {
+	{ .compatible = "sifive,fu540-c000-ddr" },
+	{ }
+};
+
+U_BOOT_DRIVER(fu540_ddr) = {
+	.name = "fu540_ddr",
+	.id = UCLASS_RAM,
+	.of_match = fu540_ddr_ids,
+	.ops = &fu540_ddr_ops,
+	.probe = fu540_ddr_probe,
+	.priv_auto_alloc_size = sizeof(struct fu540_ddr_info),
+#if defined(CONFIG_SPL_BUILD)
+	.platdata_auto_alloc_size = sizeof(struct sifive_dmc_plat),
+#endif
+};