linux/drivers/mmc/host/sdhci-sirf.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * SDHCI support for SiRF primaII and marco SoCs
   4 *
   5 * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
   6 */
   7
   8#include <linux/delay.h>
   9#include <linux/device.h>
  10#include <linux/mmc/host.h>
  11#include <linux/module.h>
  12#include <linux/of.h>
  13#include <linux/mmc/slot-gpio.h>
  14#include "sdhci-pltfm.h"
  15
  16#define SDHCI_CLK_DELAY_SETTING 0x4C
  17#define SDHCI_SIRF_8BITBUS BIT(3)
  18#define SIRF_TUNING_COUNT 16384
  19
  20static void sdhci_sirf_set_bus_width(struct sdhci_host *host, int width)
  21{
  22        u8 ctrl;
  23
  24        ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
  25        ctrl &= ~(SDHCI_CTRL_4BITBUS | SDHCI_SIRF_8BITBUS);
  26
  27        /*
  28         * CSR atlas7 and prima2 SD host version is not 3.0
  29         * 8bit-width enable bit of CSR SD hosts is 3,
  30         * while stardard hosts use bit 5
  31         */
  32        if (width == MMC_BUS_WIDTH_8)
  33                ctrl |= SDHCI_SIRF_8BITBUS;
  34        else if (width == MMC_BUS_WIDTH_4)
  35                ctrl |= SDHCI_CTRL_4BITBUS;
  36
  37        sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
  38}
  39
  40static u32 sdhci_sirf_readl_le(struct sdhci_host *host, int reg)
  41{
  42        u32 val = readl(host->ioaddr + reg);
  43
  44        if (unlikely((reg == SDHCI_CAPABILITIES_1) &&
  45                        (host->mmc->caps & MMC_CAP_UHS_SDR50))) {
  46                /* fake CAP_1 register */
  47                val = SDHCI_SUPPORT_DDR50 |
  48                        SDHCI_SUPPORT_SDR50 | SDHCI_USE_SDR50_TUNING;
  49        }
  50
  51        if (unlikely(reg == SDHCI_SLOT_INT_STATUS)) {
  52                u32 prss = val;
  53                /* fake chips as V3.0 host conreoller */
  54                prss &= ~(0xFF << 16);
  55                val = prss | (SDHCI_SPEC_300 << 16);
  56        }
  57        return val;
  58}
  59
  60static u16 sdhci_sirf_readw_le(struct sdhci_host *host, int reg)
  61{
  62        u16 ret = 0;
  63
  64        ret = readw(host->ioaddr + reg);
  65
  66        if (unlikely(reg == SDHCI_HOST_VERSION)) {
  67                ret = readw(host->ioaddr + SDHCI_HOST_VERSION);
  68                ret |= SDHCI_SPEC_300;
  69        }
  70
  71        return ret;
  72}
  73
  74static int sdhci_sirf_execute_tuning(struct sdhci_host *host, u32 opcode)
  75{
  76        int tuning_seq_cnt = 3;
  77        int phase;
  78        u8 tuned_phase_cnt = 0;
  79        int rc = 0, longest_range = 0;
  80        int start = -1, end = 0, tuning_value = -1, range = 0;
  81        u16 clock_setting;
  82        struct mmc_host *mmc = host->mmc;
  83
  84        clock_setting = sdhci_readw(host, SDHCI_CLK_DELAY_SETTING);
  85        clock_setting &= ~0x3fff;
  86
  87retry:
  88        phase = 0;
  89        tuned_phase_cnt = 0;
  90        do {
  91                sdhci_writel(host,
  92                        clock_setting | phase,
  93                        SDHCI_CLK_DELAY_SETTING);
  94
  95                if (!mmc_send_tuning(mmc, opcode, NULL)) {
  96                        /* Tuning is successful at this tuning point */
  97                        tuned_phase_cnt++;
  98                        dev_dbg(mmc_dev(mmc), "%s: Found good phase = %d\n",
  99                                 mmc_hostname(mmc), phase);
 100                        if (start == -1)
 101                                start = phase;
 102                        end = phase;
 103                        range++;
 104                        if (phase == (SIRF_TUNING_COUNT - 1)
 105                                && range > longest_range)
 106                                tuning_value = (start + end) / 2;
 107                } else {
 108                        dev_dbg(mmc_dev(mmc), "%s: Found bad phase = %d\n",
 109                                 mmc_hostname(mmc), phase);
 110                        if (range > longest_range) {
 111                                tuning_value = (start + end) / 2;
 112                                longest_range = range;
 113                        }
 114                        start = -1;
 115                        end = range = 0;
 116                }
 117        } while (++phase < SIRF_TUNING_COUNT);
 118
 119        if (tuned_phase_cnt && tuning_value > 0) {
 120                /*
 121                 * Finally set the selected phase in delay
 122                 * line hw block.
 123                 */
 124                phase = tuning_value;
 125                sdhci_writel(host,
 126                        clock_setting | phase,
 127                        SDHCI_CLK_DELAY_SETTING);
 128
 129                dev_dbg(mmc_dev(mmc), "%s: Setting the tuning phase to %d\n",
 130                         mmc_hostname(mmc), phase);
 131        } else {
 132                if (--tuning_seq_cnt)
 133                        goto retry;
 134                /* Tuning failed */
 135                dev_dbg(mmc_dev(mmc), "%s: No tuning point found\n",
 136                       mmc_hostname(mmc));
 137                rc = -EIO;
 138        }
 139
 140        return rc;
 141}
 142
 143static const struct sdhci_ops sdhci_sirf_ops = {
 144        .read_l = sdhci_sirf_readl_le,
 145        .read_w = sdhci_sirf_readw_le,
 146        .platform_execute_tuning = sdhci_sirf_execute_tuning,
 147        .set_clock = sdhci_set_clock,
 148        .get_max_clock  = sdhci_pltfm_clk_get_max_clock,
 149        .set_bus_width = sdhci_sirf_set_bus_width,
 150        .reset = sdhci_reset,
 151        .set_uhs_signaling = sdhci_set_uhs_signaling,
 152};
 153
 154static const struct sdhci_pltfm_data sdhci_sirf_pdata = {
 155        .ops = &sdhci_sirf_ops,
 156        .quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
 157                SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
 158                SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
 159                SDHCI_QUIRK_RESET_CMD_DATA_ON_IOS,
 160        .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
 161};
 162
 163static int sdhci_sirf_probe(struct platform_device *pdev)
 164{
 165        struct sdhci_host *host;
 166        struct sdhci_pltfm_host *pltfm_host;
 167        struct clk *clk;
 168        int ret;
 169
 170        clk = devm_clk_get(&pdev->dev, NULL);
 171        if (IS_ERR(clk)) {
 172                dev_err(&pdev->dev, "unable to get clock");
 173                return PTR_ERR(clk);
 174        }
 175
 176        host = sdhci_pltfm_init(pdev, &sdhci_sirf_pdata, 0);
 177        if (IS_ERR(host))
 178                return PTR_ERR(host);
 179
 180        pltfm_host = sdhci_priv(host);
 181        pltfm_host->clk = clk;
 182
 183        sdhci_get_of_property(pdev);
 184
 185        ret = clk_prepare_enable(pltfm_host->clk);
 186        if (ret)
 187                goto err_clk_prepare;
 188
 189        ret = sdhci_add_host(host);
 190        if (ret)
 191                goto err_sdhci_add;
 192
 193        /*
 194         * We must request the IRQ after sdhci_add_host(), as the tasklet only
 195         * gets setup in sdhci_add_host() and we oops.
 196         */
 197        ret = mmc_gpiod_request_cd(host->mmc, "cd", 0, false, 0, NULL);
 198        if (ret == -EPROBE_DEFER)
 199                goto err_request_cd;
 200        if (!ret)
 201                mmc_gpiod_request_cd_irq(host->mmc);
 202
 203        return 0;
 204
 205err_request_cd:
 206        sdhci_remove_host(host, 0);
 207err_sdhci_add:
 208        clk_disable_unprepare(pltfm_host->clk);
 209err_clk_prepare:
 210        sdhci_pltfm_free(pdev);
 211        return ret;
 212}
 213
 214static const struct of_device_id sdhci_sirf_of_match[] = {
 215        { .compatible = "sirf,prima2-sdhc" },
 216        { }
 217};
 218MODULE_DEVICE_TABLE(of, sdhci_sirf_of_match);
 219
 220static struct platform_driver sdhci_sirf_driver = {
 221        .driver         = {
 222                .name   = "sdhci-sirf",
 223                .of_match_table = sdhci_sirf_of_match,
 224                .pm     = &sdhci_pltfm_pmops,
 225        },
 226        .probe          = sdhci_sirf_probe,
 227        .remove         = sdhci_pltfm_unregister,
 228};
 229
 230module_platform_driver(sdhci_sirf_driver);
 231
 232MODULE_DESCRIPTION("SDHCI driver for SiRFprimaII/SiRFmarco");
 233MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 234MODULE_LICENSE("GPL v2");
 235