drivers/mmc/host/dw_mmc-zx.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * ZX Specific Extensions for Synopsys DW Multimedia Card Interface driver
   4  *
   5  * Copyright (C) 2016, Linaro Ltd.
   6  * Copyright (C) 2016, ZTE Corp.
   7  */
   8
   9 #include <linux/clk.h>
  10 #include <linux/mfd/syscon.h>
  11 #include <linux/mmc/host.h>
  12 #include <linux/mmc/mmc.h>
  13 #include <linux/module.h>
  14 #include <linux/of.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/pm_runtime.h>
  17 #include <linux/regmap.h>
  18 #include <linux/slab.h>
  19
  20 #include "dw_mmc.h"
  21 #include "dw_mmc-pltfm.h"
  22 #include "dw_mmc-zx.h"
  23
  24 struct dw_mci_zx_priv_data {
  25         struct regmap   *sysc_base;
  26 };
  27
  28 enum delay_type {
  29         DELAY_TYPE_READ,        /* read dqs delay */
  30         DELAY_TYPE_CLK,         /* clk sample delay */
  31 };
  32
  33 static int dw_mci_zx_emmc_set_delay(struct dw_mci *host, unsigned int delay,
  34                                     enum delay_type dflag)
  35 {
  36         struct dw_mci_zx_priv_data *priv = host->priv;
  37         struct regmap *sysc_base = priv->sysc_base;
  38         unsigned int clksel;
  39         unsigned int loop = 1000;
  40         int ret;
  41
  42         if (!sysc_base)
  43                 return -EINVAL;
  44
  45         ret = regmap_update_bits(sysc_base, LB_AON_EMMC_CFG_REG0,
  46                                  PARA_HALF_CLK_MODE | PARA_DLL_BYPASS_MODE |
  47                                  PARA_PHASE_DET_SEL_MASK |
  48                                  PARA_DLL_LOCK_NUM_MASK |
  49                                  DLL_REG_SET | PARA_DLL_START_MASK,
  50                                  PARA_DLL_START(4) | PARA_DLL_LOCK_NUM(4));
  51         if (ret)
  52                 return ret;
  53
  54         ret = regmap_read(sysc_base, LB_AON_EMMC_CFG_REG1, &clksel);
  55         if (ret)
  56                 return ret;
  57
  58         if (dflag == DELAY_TYPE_CLK) {
  59                 clksel &= ~CLK_SAMP_DELAY_MASK;
  60                 clksel |= CLK_SAMP_DELAY(delay);
  61         } else {
  62                 clksel &= ~READ_DQS_DELAY_MASK;
  63                 clksel |= READ_DQS_DELAY(delay);
  64         }
  65
  66         regmap_write(sysc_base, LB_AON_EMMC_CFG_REG1, clksel);
  67         regmap_update_bits(sysc_base, LB_AON_EMMC_CFG_REG0,
  68                            PARA_DLL_START_MASK | PARA_DLL_LOCK_NUM_MASK |
  69                            DLL_REG_SET,
  70                            PARA_DLL_START(4) | PARA_DLL_LOCK_NUM(4) |
  71                            DLL_REG_SET);
  72
  73         do {
  74                 ret = regmap_read(sysc_base, LB_AON_EMMC_CFG_REG2, &clksel);
  75                 if (ret)
  76                         return ret;
  77
  78         } while (--loop && !(clksel & ZX_DLL_LOCKED));
  79
  80         if (!loop) {
  81                 dev_err(host->dev, "Error: %s dll lock fail\n", __func__);
  82                 return -EIO;
  83         }
  84
  85         return 0;
  86 }
  87
  88 static int dw_mci_zx_emmc_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
  89 {
  90         struct dw_mci *host = slot->host;
  91         struct mmc_host *mmc = slot->mmc;
  92         int ret, len = 0, start = 0, end = 0, delay, best = 0;
  93
  94         for (delay = 1; delay < 128; delay++) {
  95                 ret = dw_mci_zx_emmc_set_delay(host, delay, DELAY_TYPE_CLK);
  96                 if (!ret && mmc_send_tuning(mmc, opcode, NULL)) {
  97                         if (start >= 0) {
  98                                 end = delay - 1;
  99                                 /* check and update longest good range */
 100                                 if ((end - start) > len) {
 101                                         best = (start + end) >> 1;
 102                                         len = end - start;
 103                                 }
 104                         }
 105                         start = -1;
 106                         end = 0;
 107                         continue;
 108                 }
 109                 if (start < 0)
 110                         start = delay;
 111         }
 112
 113         if (start >= 0) {
 114                 end = delay - 1;
 115                 if ((end - start) > len) {
 116                         best = (start + end) >> 1;
 117                         len = end - start;
 118                 }
 119         }
 120         if (best < 0)
 121                 return -EIO;
 122
 123         dev_info(host->dev, "%s best range: start %d end %d\n", __func__,
 124                  start, end);
 125         return dw_mci_zx_emmc_set_delay(host, best, DELAY_TYPE_CLK);
 126 }
 127
 128 static int dw_mci_zx_prepare_hs400_tuning(struct dw_mci *host,
 129                                           struct mmc_ios *ios)
 130 {
 131         int ret;
 132
 133         /* config phase shift as 90 degree */
 134         ret = dw_mci_zx_emmc_set_delay(host, 32, DELAY_TYPE_READ);
 135         if (ret < 0)
 136                 return -EIO;
 137
 138         return 0;
 139 }
 140
 141 static int dw_mci_zx_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
 142 {
 143         struct dw_mci *host = slot->host;
 144
 145         if (host->verid == 0x290a) /* only for emmc */
 146                 return dw_mci_zx_emmc_execute_tuning(slot, opcode);
 147         /* TODO: Add 0x210a dedicated tuning for sd/sdio */
 148
 149         return 0;
 150 }
 151
 152 static int dw_mci_zx_parse_dt(struct dw_mci *host)
 153 {
 154         struct device_node *np = host->dev->of_node;
 155         struct device_node *node;
 156         struct dw_mci_zx_priv_data *priv;
 157         struct regmap *sysc_base;
 158         int ret;
 159
 160         /* syscon is needed only by emmc */
 161         node = of_parse_phandle(np, "zte,aon-syscon", 0);
 162         if (node) {
 163                 sysc_base = syscon_node_to_regmap(node);
 164                 of_node_put(node);
 165
 166                 if (IS_ERR(sysc_base)) {
 167                         ret = PTR_ERR(sysc_base);
 168                         if (ret != -EPROBE_DEFER)
 169                                 dev_err(host->dev, "Can't get syscon: %d\n",
 170                                         ret);
 171                         return ret;
 172                 }
 173         } else {
 174                 return 0;
 175         }
 176
 177         priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
 178         if (!priv)
 179                 return -ENOMEM;
 180         priv->sysc_base = sysc_base;
 181         host->priv = priv;
 182
 183         return 0;
 184 }
 185
 186 static unsigned long zx_dwmmc_caps[3] = {
 187         MMC_CAP_CMD23,
 188         MMC_CAP_CMD23,
 189         MMC_CAP_CMD23,
 190 };
 191
 192 static const struct dw_mci_drv_data zx_drv_data = {
 193         .caps                   = zx_dwmmc_caps,
 194         .num_caps               = ARRAY_SIZE(zx_dwmmc_caps),
 195         .execute_tuning         = dw_mci_zx_execute_tuning,
 196         .prepare_hs400_tuning   = dw_mci_zx_prepare_hs400_tuning,
 197         .parse_dt               = dw_mci_zx_parse_dt,
 198 };
 199
 200 static const struct of_device_id dw_mci_zx_match[] = {
 201         { .compatible = "zte,zx296718-dw-mshc", .data = &zx_drv_data},
 202         {},
 203 };
 204 MODULE_DEVICE_TABLE(of, dw_mci_zx_match);
 205
 206 static int dw_mci_zx_probe(struct platform_device *pdev)
 207 {
 208         const struct dw_mci_drv_data *drv_data;
 209         const struct of_device_id *match;
 210
 211         match = of_match_node(dw_mci_zx_match, pdev->dev.of_node);
 212         drv_data = match->data;
 213
 214         return dw_mci_pltfm_register(pdev, drv_data);
 215 }
 216
 217 static const struct dev_pm_ops dw_mci_zx_dev_pm_ops = {
 218         SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 219                                 pm_runtime_force_resume)
 220         SET_RUNTIME_PM_OPS(dw_mci_runtime_suspend,
 221                            dw_mci_runtime_resume,
 222                            NULL)
 223 };
 224
 225 static struct platform_driver dw_mci_zx_pltfm_driver = {
 226         .probe          = dw_mci_zx_probe,
 227         .remove         = dw_mci_pltfm_remove,
 228         .driver         = {
 229                 .name           = "dwmmc_zx",
 230                 .of_match_table = dw_mci_zx_match,
 231                 .pm             = &dw_mci_zx_dev_pm_ops,
 232         },
 233 };
 234
 235 module_platform_driver(dw_mci_zx_pltfm_driver);
 236
 237 MODULE_DESCRIPTION("ZTE emmc/sd driver");
 238 MODULE_LICENSE("GPL v2");