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1// SPDX-License-Identifier: GPL-2.02/*3 * StarFive Designware Mobile Storage Host Controller Driver4 *5 * Copyright (c) 2022 StarFive Technology Co., Ltd.6 */7 8#include <linux/bitfield.h>9#include <linux/clk.h>10#include <linux/delay.h>11#include <linux/mfd/syscon.h>12#include <linux/mmc/host.h>13#include <linux/module.h>14#include <linux/of_address.h>15#include <linux/platform_device.h>16#include <linux/regmap.h>17 18#include "dw_mmc.h"19#include "dw_mmc-pltfm.h"20 21#define ALL_INT_CLR 0x1ffff22#define MAX_DELAY_CHAIN 3223 24#define STARFIVE_SMPL_PHASE GENMASK(20, 16)25 26static void dw_mci_starfive_set_ios(struct dw_mci *host, struct mmc_ios *ios)27{28 int ret;29 unsigned int clock;30 31 if (ios->timing == MMC_TIMING_MMC_DDR52 || ios->timing == MMC_TIMING_UHS_DDR50) {32 clock = (ios->clock > 50000000 && ios->clock <= 52000000) ? 100000000 : ios->clock;33 ret = clk_set_rate(host->ciu_clk, clock);34 if (ret)35 dev_dbg(host->dev, "Use an external frequency divider %uHz\n", ios->clock);36 host->bus_hz = clk_get_rate(host->ciu_clk);37 } else {38 dev_dbg(host->dev, "Using the internal divider\n");39 }40}41 42static void dw_mci_starfive_set_sample_phase(struct dw_mci *host, u32 smpl_phase)43{44 /* change driver phase and sample phase */45 u32 reg_value = mci_readl(host, UHS_REG_EXT);46 47 /* In UHS_REG_EXT, only 5 bits valid in DRV_PHASE and SMPL_PHASE */48 reg_value &= ~STARFIVE_SMPL_PHASE;49 reg_value |= FIELD_PREP(STARFIVE_SMPL_PHASE, smpl_phase);50 mci_writel(host, UHS_REG_EXT, reg_value);51 52 /* We should delay 1ms wait for timing setting finished. */53 mdelay(1);54}55 56static int dw_mci_starfive_execute_tuning(struct dw_mci_slot *slot,57 u32 opcode)58{59 static const int grade = MAX_DELAY_CHAIN;60 struct dw_mci *host = slot->host;61 int smpl_phase, smpl_raise = -1, smpl_fall = -1;62 int ret;63 64 for (smpl_phase = 0; smpl_phase < grade; smpl_phase++) {65 dw_mci_starfive_set_sample_phase(host, smpl_phase);66 mci_writel(host, RINTSTS, ALL_INT_CLR);67 68 ret = mmc_send_tuning(slot->mmc, opcode, NULL);69 70 if (!ret && smpl_raise < 0) {71 smpl_raise = smpl_phase;72 } else if (ret && smpl_raise >= 0) {73 smpl_fall = smpl_phase - 1;74 break;75 }76 }77 78 if (smpl_phase >= grade)79 smpl_fall = grade - 1;80 81 if (smpl_raise < 0) {82 smpl_phase = 0;83 dev_err(host->dev, "No valid delay chain! use default\n");84 ret = -EINVAL;85 goto out;86 }87 88 smpl_phase = (smpl_raise + smpl_fall) / 2;89 dev_dbg(host->dev, "Found valid delay chain! use it [delay=%d]\n", smpl_phase);90 ret = 0;91 92out:93 dw_mci_starfive_set_sample_phase(host, smpl_phase);94 mci_writel(host, RINTSTS, ALL_INT_CLR);95 return ret;96}97 98static const struct dw_mci_drv_data starfive_data = {99 .common_caps = MMC_CAP_CMD23,100 .set_ios = dw_mci_starfive_set_ios,101 .execute_tuning = dw_mci_starfive_execute_tuning,102};103 104static const struct of_device_id dw_mci_starfive_match[] = {105 { .compatible = "starfive,jh7110-mmc",106 .data = &starfive_data },107 {},108};109MODULE_DEVICE_TABLE(of, dw_mci_starfive_match);110 111static int dw_mci_starfive_probe(struct platform_device *pdev)112{113 return dw_mci_pltfm_register(pdev, &starfive_data);114}115 116static struct platform_driver dw_mci_starfive_driver = {117 .probe = dw_mci_starfive_probe,118 .remove_new = dw_mci_pltfm_remove,119 .driver = {120 .name = "dwmmc_starfive",121 .probe_type = PROBE_PREFER_ASYNCHRONOUS,122 .of_match_table = dw_mci_starfive_match,123 },124};125module_platform_driver(dw_mci_starfive_driver);126 127MODULE_DESCRIPTION("StarFive JH7110 Specific DW-MSHC Driver Extension");128MODULE_LICENSE("GPL");129MODULE_ALIAS("platform:dwmmc_starfive");130