drivers/ram/aspeed/sdram_ast2500.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2012-2020  ASPEED Technology Inc.
 *
 * Copyright 2016 Google, Inc
 */

#include <config.h>
#include <clk.h>
#include <dm.h>
#include <errno.h>
#include <log.h>
#include <ram.h>
#include <regmap.h>
#include <reset.h>
#include <asm/global_data.h>
#include <asm/io.h>
#include <asm/arch/scu_ast2500.h>
#include <asm/arch/sdram_ast2500.h>
#include <asm/arch/wdt.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <dt-bindings/clock/aspeed-clock.h>

/* These configuration parameters are taken from Aspeed SDK */
#define DDR4_MR46_MODE		0x08000000
#define DDR4_MR5_MODE		0x400
#define DDR4_MR13_MODE		0x101
#define DDR4_MR02_MODE		0x410
#define DDR4_TRFC		0x45457188

#define PHY_CFG_SIZE		15

static const u32 ddr4_ac_timing[3] = {0x63604e37, 0xe97afa99, 0x00019000};
static const struct {
	u32 index[PHY_CFG_SIZE];
	u32 value[PHY_CFG_SIZE];
} ddr4_phy_config = {
	.index = {0, 1, 3, 4, 5, 56, 57, 58, 59, 60, 61, 62, 36, 49, 50},
	.value = {
		0x42492aae, 0x09002000, 0x55e00b0b, 0x20000000, 0x24,
		0x03002900, 0x0e0000a0, 0x000e001c, 0x35b8c106, 0x08080607,
		0x9b000900, 0x0e400a00, 0x00100008, 0x3c183c3c, 0x00631e0e,
	},
};

#define SDRAM_MAX_SIZE		(1024 * 1024 * 1024)
#define SDRAM_MIN_SIZE		(128 * 1024 * 1024)

DECLARE_GLOBAL_DATA_PTR;

/*
 * Bandwidth configuration parameters for different SDRAM requests.
 * These are hardcoded settings taken from Aspeed SDK.
 */
static const u32 ddr_max_grant_params[4] = {
	0x88448844, 0x24422288, 0x22222222, 0x22222222
};

/*
 * These registers are not documented by Aspeed at all.
 * All writes and reads are taken pretty much as is from SDK.
 */
struct ast2500_ddr_phy {
	u32 phy[117];
};

struct dram_info {
	struct ram_info info;
	struct clk ddr_clk;
	struct ast2500_sdrammc_regs *regs;
	struct ast2500_scu *scu;
	struct ast2500_ddr_phy *phy;
	ulong clock_rate;
};

static int ast2500_sdrammc_init_phy(struct ast2500_ddr_phy *phy)
{
	writel(0, &phy->phy[2]);
	writel(0, &phy->phy[6]);
	writel(0, &phy->phy[8]);
	writel(0, &phy->phy[10]);
	writel(0, &phy->phy[12]);
	writel(0, &phy->phy[42]);
	writel(0, &phy->phy[44]);

	writel(0x86000000, &phy->phy[16]);
	writel(0x00008600, &phy->phy[17]);
	writel(0x80000000, &phy->phy[18]);
	writel(0x80808080, &phy->phy[19]);

	return 0;
}

static void ast2500_ddr_phy_init_process(struct dram_info *info)
{
	struct ast2500_sdrammc_regs *regs = info->regs;

	writel(0, &regs->phy_ctrl[0]);
	writel(0x4040, &info->phy->phy[51]);

	writel(SDRAM_PHYCTRL0_NRST | SDRAM_PHYCTRL0_INIT, &regs->phy_ctrl[0]);
	while ((readl(&regs->phy_ctrl[0]) & SDRAM_PHYCTRL0_INIT))
		;
	writel(SDRAM_PHYCTRL0_NRST | SDRAM_PHYCTRL0_AUTO_UPDATE,
	       &regs->phy_ctrl[0]);
}

static void ast2500_sdrammc_set_vref(struct dram_info *info, u32 vref)
{
	writel(0, &info->regs->phy_ctrl[0]);
	writel((vref << 8) | 0x6, &info->phy->phy[48]);
	ast2500_ddr_phy_init_process(info);
}

static int ast2500_ddr_cbr_test(struct dram_info *info)
{
	struct ast2500_sdrammc_regs *regs = info->regs;
	int i;
	const u32 test_params = SDRAM_TEST_EN
			| SDRAM_TEST_ERRSTOP
			| SDRAM_TEST_TWO_MODES;
	int ret = 0;

	writel((1 << SDRAM_REFRESH_CYCLES_SHIFT) |
	       (0x5c << SDRAM_REFRESH_PERIOD_SHIFT), &regs->refresh_timing);
	writel((0xfff << SDRAM_TEST_LEN_SHIFT), &regs->test_addr);
	writel(0xff00ff00, &regs->test_init_val);
	writel(SDRAM_TEST_EN | (SDRAM_TEST_MODE_RW << SDRAM_TEST_MODE_SHIFT) |
	       SDRAM_TEST_ERRSTOP, &regs->ecc_test_ctrl);

	while (!(readl(&regs->ecc_test_ctrl) & SDRAM_TEST_DONE))
		;

	if (readl(&regs->ecc_test_ctrl) & SDRAM_TEST_FAIL) {
		ret = -EIO;
	} else {
		for (i = 0; i <= SDRAM_TEST_GEN_MODE_MASK; ++i) {
			writel((i << SDRAM_TEST_GEN_MODE_SHIFT) | test_params,
			       &regs->ecc_test_ctrl);
			while (!(readl(&regs->ecc_test_ctrl) & SDRAM_TEST_DONE))
				;
			if (readl(&regs->ecc_test_ctrl) & SDRAM_TEST_FAIL) {
				ret = -EIO;
				break;
			}
		}
	}

	writel(0, &regs->refresh_timing);
	writel(0, &regs->ecc_test_ctrl);

	return ret;
}

static int ast2500_sdrammc_ddr4_calibrate_vref(struct dram_info *info)
{
	int i;
	int vref_min = 0xff;
	int vref_max = 0;
	int range_size = 0;

	for (i = 1; i < 0x40; ++i) {
		int res;

		ast2500_sdrammc_set_vref(info, i);
		res = ast2500_ddr_cbr_test(info);
		if (res < 0) {
			if (range_size > 0)
				break;
		} else {
			++range_size;
			vref_min = min(vref_min, i);
			vref_max = max(vref_max, i);
		}
	}

	/* Pick average setting */
	ast2500_sdrammc_set_vref(info, (vref_min + vref_max + 1) / 2);

	return 0;
}

static size_t ast2500_sdrammc_get_vga_mem_size(struct dram_info *info)
{
	size_t vga_mem_size_base = 8 * 1024 * 1024;
	u32 vga_hwconf = (readl(&info->scu->hwstrap) & SCU_HWSTRAP_VGAMEM_MASK)
	    >> SCU_HWSTRAP_VGAMEM_SHIFT;

	return vga_mem_size_base << vga_hwconf;
}

/*
 * Find out RAM size and save it in dram_info
 *
 * The procedure is taken from Aspeed SDK
 */
static void ast2500_sdrammc_calc_size(struct dram_info *info)
{
	/* The controller supports 128/256/512/1024 MB ram */
	size_t ram_size = SDRAM_MIN_SIZE;
	const int write_test_offset = 0x100000;
	u32 test_pattern = 0xdeadbeef;
	u32 cap_param = SDRAM_CONF_CAP_1024M;
	u32 refresh_timing_param = DDR4_TRFC;
	const u32 write_addr_base = CFG_SYS_SDRAM_BASE + write_test_offset;

	for (ram_size = SDRAM_MAX_SIZE; ram_size > SDRAM_MIN_SIZE;
	     ram_size >>= 1) {
		writel(test_pattern, write_addr_base + (ram_size >> 1));
		test_pattern = (test_pattern >> 4) | (test_pattern << 28);
	}

	/* One last write to overwrite all wrapped values */
	writel(test_pattern, write_addr_base);

	/* Reset the pattern and see which value was really written */
	test_pattern = 0xdeadbeef;
	for (ram_size = SDRAM_MAX_SIZE; ram_size > SDRAM_MIN_SIZE;
	     ram_size >>= 1) {
		if (readl(write_addr_base + (ram_size >> 1)) == test_pattern)
			break;

		--cap_param;
		refresh_timing_param >>= 8;
		test_pattern = (test_pattern >> 4) | (test_pattern << 28);
	}

	clrsetbits_le32(&info->regs->ac_timing[1],
			(SDRAM_AC_TRFC_MASK << SDRAM_AC_TRFC_SHIFT),
			((refresh_timing_param & SDRAM_AC_TRFC_MASK)
			 << SDRAM_AC_TRFC_SHIFT));

	info->info.base = CFG_SYS_SDRAM_BASE;
	info->info.size = ram_size - ast2500_sdrammc_get_vga_mem_size(info);
	clrsetbits_le32(&info->regs->config,
			(SDRAM_CONF_CAP_MASK << SDRAM_CONF_CAP_SHIFT),
			((cap_param & SDRAM_CONF_CAP_MASK)
			 << SDRAM_CONF_CAP_SHIFT));
}

static int ast2500_sdrammc_init_ddr4(struct dram_info *info)
{
	int i;
	const u32 power_control = SDRAM_PCR_CKE_EN
	    | (1 << SDRAM_PCR_CKE_DELAY_SHIFT)
	    | (2 << SDRAM_PCR_TCKE_PW_SHIFT)
	    | SDRAM_PCR_RESETN_DIS
	    | SDRAM_PCR_RGAP_CTRL_EN | SDRAM_PCR_ODT_EN | SDRAM_PCR_ODT_EXT_EN;
	const u32 conf = (SDRAM_CONF_CAP_1024M << SDRAM_CONF_CAP_SHIFT)
#ifdef CONFIG_ASPEED_DDR4_DUALX8
	    | SDRAM_CONF_DUALX8
#endif
	    | SDRAM_CONF_SCRAMBLE | SDRAM_CONF_SCRAMBLE_PAT2 | SDRAM_CONF_DDR4;
	int ret;

	writel(conf, &info->regs->config);
	for (i = 0; i < ARRAY_SIZE(ddr4_ac_timing); ++i)
		writel(ddr4_ac_timing[i], &info->regs->ac_timing[i]);

	writel(DDR4_MR46_MODE, &info->regs->mr46_mode_setting);
	writel(DDR4_MR5_MODE, &info->regs->mr5_mode_setting);
	writel(DDR4_MR02_MODE, &info->regs->mr02_mode_setting);
	writel(DDR4_MR13_MODE, &info->regs->mr13_mode_setting);

	for (i = 0; i < PHY_CFG_SIZE; ++i) {
		writel(ddr4_phy_config.value[i],
		       &info->phy->phy[ddr4_phy_config.index[i]]);
	}

	writel(power_control, &info->regs->power_control);

	ast2500_ddr_phy_init_process(info);

	ret = ast2500_sdrammc_ddr4_calibrate_vref(info);
	if (ret < 0) {
		debug("Vref calibration failed!\n");
		return ret;
	}

	writel((1 << SDRAM_REFRESH_CYCLES_SHIFT)
	       | SDRAM_REFRESH_ZQCS_EN | (0x2f << SDRAM_REFRESH_PERIOD_SHIFT),
	       &info->regs->refresh_timing);

	setbits_le32(&info->regs->power_control,
		     SDRAM_PCR_AUTOPWRDN_EN | SDRAM_PCR_ODT_AUTO_ON);

	ast2500_sdrammc_calc_size(info);

	setbits_le32(&info->regs->config, SDRAM_CONF_CACHE_INIT_EN);
	while (!(readl(&info->regs->config) & SDRAM_CONF_CACHE_INIT_DONE))
		;
	setbits_le32(&info->regs->config, SDRAM_CONF_CACHE_EN);

	writel(SDRAM_MISC_DDR4_TREFRESH, &info->regs->misc_control);

	/* Enable all requests except video & display */
	writel(SDRAM_REQ_USB20_EHCI1
	       | SDRAM_REQ_USB20_EHCI2
	       | SDRAM_REQ_CPU
	       | SDRAM_REQ_AHB2
	       | SDRAM_REQ_AHB
	       | SDRAM_REQ_MAC0
	       | SDRAM_REQ_MAC1
	       | SDRAM_REQ_PCIE
	       | SDRAM_REQ_XDMA
	       | SDRAM_REQ_ENCRYPTION
	       | SDRAM_REQ_VIDEO_FLAG
	       | SDRAM_REQ_VIDEO_LOW_PRI_WRITE
	       | SDRAM_REQ_2D_RW
	       | SDRAM_REQ_MEMCHECK, &info->regs->req_limit_mask);

	return 0;
}

static void ast2500_sdrammc_unlock(struct dram_info *info)
{
	writel(SDRAM_UNLOCK_KEY, &info->regs->protection_key);
	while (!readl(&info->regs->protection_key))
		;
}

static void ast2500_sdrammc_lock(struct dram_info *info)
{
	writel(~SDRAM_UNLOCK_KEY, &info->regs->protection_key);
	while (readl(&info->regs->protection_key))
		;
}

static int ast2500_sdrammc_probe(struct udevice *dev)
{
	struct reset_ctl reset_ctl;
	struct dram_info *priv = (struct dram_info *)dev_get_priv(dev);
	struct ast2500_sdrammc_regs *regs = priv->regs;
	int i;
	int ret = clk_get_by_index(dev, 0, &priv->ddr_clk);

	if (ret) {
		debug("DDR:No CLK\n");
		return ret;
	}

	priv->scu = ast_get_scu();
	if (IS_ERR(priv->scu)) {
		debug("%s(): can't get SCU\n", __func__);
		return PTR_ERR(priv->scu);
	}

	clk_set_rate(&priv->ddr_clk, priv->clock_rate);
	ret = reset_get_by_index(dev, 0, &reset_ctl);
	if (ret) {
		debug("%s(): Failed to get reset signal\n", __func__);
		return ret;
	}

	ret = reset_assert(&reset_ctl);
	if (ret) {
		debug("%s(): SDRAM reset failed: %u\n", __func__, ret);
		return ret;
	}

	ast2500_sdrammc_unlock(priv);

	writel(SDRAM_PCR_MREQI_DIS | SDRAM_PCR_RESETN_DIS,
	       &regs->power_control);
	writel(SDRAM_VIDEO_UNLOCK_KEY, &regs->gm_protection_key);

	/* Mask all requests except CPU and AHB during PHY init */
	writel(~(SDRAM_REQ_CPU | SDRAM_REQ_AHB), &regs->req_limit_mask);

	for (i = 0; i < ARRAY_SIZE(ddr_max_grant_params); ++i)
		writel(ddr_max_grant_params[i], &regs->max_grant_len[i]);

	setbits_le32(&regs->intr_ctrl, SDRAM_ICR_RESET_ALL);

	ast2500_sdrammc_init_phy(priv->phy);
	if (readl(&priv->scu->hwstrap) & SCU_HWSTRAP_DDR4) {
		ast2500_sdrammc_init_ddr4(priv);
	} else {
		debug("Unsupported DRAM3\n");
		return -EINVAL;
	}

	clrbits_le32(&regs->intr_ctrl, SDRAM_ICR_RESET_ALL);
	ast2500_sdrammc_lock(priv);

	return 0;
}

static int ast2500_sdrammc_of_to_plat(struct udevice *dev)
{
	struct dram_info *priv = dev_get_priv(dev);
	struct regmap *map;
	int ret;

	ret = regmap_init_mem(dev_ofnode(dev), &map);
	if (ret)
		return ret;

	priv->regs = regmap_get_range(map, 0);
	priv->phy = regmap_get_range(map, 1);

	priv->clock_rate = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
					  "clock-frequency", 0);

	if (!priv->clock_rate) {
		debug("DDR Clock Rate not defined\n");
		return -EINVAL;
	}

	return 0;
}

static int ast2500_sdrammc_get_info(struct udevice *dev, struct ram_info *info)
{
	struct dram_info *priv = dev_get_priv(dev);

	*info = priv->info;

	return 0;
}

static struct ram_ops ast2500_sdrammc_ops = {
	.get_info = ast2500_sdrammc_get_info,
};

static const struct udevice_id ast2500_sdrammc_ids[] = {
	{ .compatible = "aspeed,ast2500-sdrammc" },
	{ }
};

U_BOOT_DRIVER(sdrammc_ast2500) = {
	.name = "aspeed_ast2500_sdrammc",
	.id = UCLASS_RAM,
	.of_match = ast2500_sdrammc_ids,
	.ops = &ast2500_sdrammc_ops,
	.of_to_plat = ast2500_sdrammc_of_to_plat,
	.probe = ast2500_sdrammc_probe,
	.priv_auto	= sizeof(struct dram_info),
};