drivers/mmc/host/dw_mmc-hi3798mv200.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Modified from dw_mmc-hi3798cv200.c
   4  *
   5  * Copyright (c) 2024 Yang Xiwen <forbidden405@outlook.com>
   6  * Copyright (c) 2018 HiSilicon Technologies Co., Ltd.
   7  */
   8
   9 #include <linux/clk.h>
  10 #include <linux/mfd/syscon.h>
  11 #include <linux/mmc/host.h>
  12 #include <linux/module.h>
  13 #include <linux/of_address.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/regmap.h>
  16
  17 #include "dw_mmc.h"
  18 #include "dw_mmc-pltfm.h"
  19
  20 #define SDMMC_TUNING_CTRL       0x118
  21 #define SDMMC_TUNING_FIND_EDGE  BIT(5)
  22
  23 #define ALL_INT_CLR             0x1ffff
  24
  25 /* DLL ctrl reg */
  26 #define SAP_DLL_CTRL_DLLMODE    BIT(16)
  27
  28 struct dw_mci_hi3798mv200_priv {
  29         struct clk *sample_clk;
  30         struct clk *drive_clk;
  31         struct regmap *crg_reg;
  32         u32 sap_dll_offset;
  33         struct mmc_clk_phase_map phase_map;
  34 };
  35
  36 static void dw_mci_hi3798mv200_set_ios(struct dw_mci *host, struct mmc_ios *ios)
  37 {
  38         struct dw_mci_hi3798mv200_priv *priv = host->priv;
  39         struct mmc_clk_phase phase = priv->phase_map.phase[ios->timing];
  40         u32 val;
  41
  42         val = mci_readl(host, ENABLE_SHIFT);
  43         if (ios->timing == MMC_TIMING_MMC_DDR52
  44             || ios->timing == MMC_TIMING_UHS_DDR50)
  45                 val |= SDMMC_ENABLE_PHASE;
  46         else
  47                 val &= ~SDMMC_ENABLE_PHASE;
  48         mci_writel(host, ENABLE_SHIFT, val);
  49
  50         val = mci_readl(host, DDR_REG);
  51         if (ios->timing == MMC_TIMING_MMC_HS400)
  52                 val |= SDMMC_DDR_HS400;
  53         else
  54                 val &= ~SDMMC_DDR_HS400;
  55         mci_writel(host, DDR_REG, val);
  56
  57         if (clk_set_rate(host->ciu_clk, ios->clock))
  58                 dev_warn(host->dev, "Failed to set rate to %u\n", ios->clock);
  59         else
  60                 /*
  61                  * CLK_MUX_ROUND_NEAREST is enabled for this clock
  62                  * The actual clock rate is not what we set, but a rounded value
  63                  * so we should get the rate once again
  64                  */
  65                 host->bus_hz = clk_get_rate(host->ciu_clk);
  66
  67         if (phase.valid) {
  68                 clk_set_phase(priv->drive_clk, phase.out_deg);
  69                 clk_set_phase(priv->sample_clk, phase.in_deg);
  70         } else {
  71                 dev_warn(host->dev,
  72                          "The phase entry for timing mode %d is missing in device tree.\n",
  73                          ios->timing);
  74         }
  75 }
  76
  77 static inline int dw_mci_hi3798mv200_enable_tuning(struct dw_mci_slot *slot)
  78 {
  79         struct dw_mci_hi3798mv200_priv *priv = slot->host->priv;
  80
  81         return regmap_clear_bits(priv->crg_reg, priv->sap_dll_offset, SAP_DLL_CTRL_DLLMODE);
  82 }
  83
  84 static inline int dw_mci_hi3798mv200_disable_tuning(struct dw_mci_slot *slot)
  85 {
  86         struct dw_mci_hi3798mv200_priv *priv = slot->host->priv;
  87
  88         return regmap_set_bits(priv->crg_reg, priv->sap_dll_offset, SAP_DLL_CTRL_DLLMODE);
  89 }
  90
  91 static int dw_mci_hi3798mv200_execute_tuning_mix_mode(struct dw_mci_slot *slot,
  92                                              u32 opcode)
  93 {
  94         static const int degrees[] = { 0, 45, 90, 135, 180, 225, 270, 315 };
  95         struct dw_mci *host = slot->host;
  96         struct dw_mci_hi3798mv200_priv *priv = host->priv;
  97         int raise_point = -1, fall_point = -1, mid;
  98         int err, prev_err = -1;
  99         int found = 0;
 100         int regval;
 101         int i;
 102         int ret;
 103
 104         ret = dw_mci_hi3798mv200_enable_tuning(slot);
 105         if (ret < 0)
 106                 return ret;
 107
 108         for (i = 0; i < ARRAY_SIZE(degrees); i++) {
 109                 clk_set_phase(priv->sample_clk, degrees[i]);
 110                 mci_writel(host, RINTSTS, ALL_INT_CLR);
 111
 112                 /*
 113                  * HiSilicon implemented a tuning mechanism.
 114                  * It needs special interaction with the DLL.
 115                  *
 116                  * Treat edge(flip) found as an error too.
 117                  */
 118                 err = mmc_send_tuning(slot->mmc, opcode, NULL);
 119                 regval = mci_readl(host, TUNING_CTRL);
 120                 if (err || (regval & SDMMC_TUNING_FIND_EDGE))
 121                         err = 1;
 122                 else
 123                         found = 1;
 124
 125                 if (i > 0) {
 126                         if (err && !prev_err)
 127                                 fall_point = i - 1;
 128                         if (!err && prev_err)
 129                                 raise_point = i;
 130                 }
 131
 132                 if (raise_point != -1 && fall_point != -1)
 133                         goto tuning_out;
 134
 135                 prev_err = err;
 136         }
 137
 138 tuning_out:
 139         ret = dw_mci_hi3798mv200_disable_tuning(slot);
 140         if (ret < 0)
 141                 return ret;
 142
 143         if (found) {
 144                 if (raise_point == -1)
 145                         raise_point = 0;
 146                 if (fall_point == -1)
 147                         fall_point = ARRAY_SIZE(degrees) - 1;
 148                 if (fall_point < raise_point) {
 149                         if ((raise_point + fall_point) >
 150                             (ARRAY_SIZE(degrees) - 1))
 151                                 mid = fall_point / 2;
 152                         else
 153                                 mid = (raise_point + ARRAY_SIZE(degrees) - 1) / 2;
 154                 } else {
 155                         mid = (raise_point + fall_point) / 2;
 156                 }
 157
 158                 /*
 159                  * We don't care what timing we are tuning for,
 160                  * simply use the same phase for all timing needs tuning.
 161                  */
 162                 priv->phase_map.phase[MMC_TIMING_MMC_HS200].in_deg = degrees[mid];
 163                 priv->phase_map.phase[MMC_TIMING_MMC_HS400].in_deg = degrees[mid];
 164                 priv->phase_map.phase[MMC_TIMING_UHS_SDR104].in_deg = degrees[mid];
 165
 166                 clk_set_phase(priv->sample_clk, degrees[mid]);
 167                 dev_dbg(host->dev, "Tuning clk_sample[%d, %d], set[%d]\n",
 168                         raise_point, fall_point, degrees[mid]);
 169                 ret = 0;
 170         } else {
 171                 dev_err(host->dev, "No valid clk_sample shift!\n");
 172                 ret = -EINVAL;
 173         }
 174
 175         mci_writel(host, RINTSTS, ALL_INT_CLR);
 176
 177         return ret;
 178 }
 179
 180 static int dw_mci_hi3798mv200_init(struct dw_mci *host)
 181 {
 182         struct dw_mci_hi3798mv200_priv *priv;
 183         struct device_node *np = host->dev->of_node;
 184         int ret;
 185
 186         priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
 187         if (!priv)
 188                 return -ENOMEM;
 189
 190         mmc_of_parse_clk_phase(host->dev, &priv->phase_map);
 191
 192         priv->sample_clk = devm_clk_get_enabled(host->dev, "ciu-sample");
 193         if (IS_ERR(priv->sample_clk))
 194                 return dev_err_probe(host->dev, PTR_ERR(priv->sample_clk),
 195                                      "failed to get enabled ciu-sample clock\n");
 196
 197         priv->drive_clk = devm_clk_get_enabled(host->dev, "ciu-drive");
 198         if (IS_ERR(priv->drive_clk))
 199                 return dev_err_probe(host->dev, PTR_ERR(priv->drive_clk),
 200                                      "failed to get enabled ciu-drive clock\n");
 201
 202         priv->crg_reg = syscon_regmap_lookup_by_phandle(np, "hisilicon,sap-dll-reg");
 203         if (IS_ERR(priv->crg_reg))
 204                 return dev_err_probe(host->dev, PTR_ERR(priv->crg_reg),
 205                                      "failed to get CRG reg\n");
 206
 207         ret = of_property_read_u32_index(np, "hisilicon,sap-dll-reg", 1, &priv->sap_dll_offset);
 208         if (ret)
 209                 return dev_err_probe(host->dev, ret, "failed to get sample DLL register offset\n");
 210
 211         host->priv = priv;
 212         return 0;
 213 }
 214
 215 static const struct dw_mci_drv_data hi3798mv200_data = {
 216         .common_caps = MMC_CAP_CMD23,
 217         .init = dw_mci_hi3798mv200_init,
 218         .set_ios = dw_mci_hi3798mv200_set_ios,
 219         .execute_tuning = dw_mci_hi3798mv200_execute_tuning_mix_mode,
 220 };
 221
 222 static const struct of_device_id dw_mci_hi3798mv200_match[] = {
 223         { .compatible = "hisilicon,hi3798mv200-dw-mshc" },
 224         {},
 225 };
 226
 227 static int dw_mci_hi3798mv200_probe(struct platform_device *pdev)
 228 {
 229         return dw_mci_pltfm_register(pdev, &hi3798mv200_data);
 230 }
 231
 232 static void dw_mci_hi3798mv200_remove(struct platform_device *pdev)
 233 {
 234         dw_mci_pltfm_remove(pdev);
 235 }
 236
 237 MODULE_DEVICE_TABLE(of, dw_mci_hi3798mv200_match);
 238 static struct platform_driver dw_mci_hi3798mv200_driver = {
 239         .probe = dw_mci_hi3798mv200_probe,
 240         .remove = dw_mci_hi3798mv200_remove,
 241         .driver = {
 242                 .name = "dwmmc_hi3798mv200",
 243                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 244                 .of_match_table = dw_mci_hi3798mv200_match,
 245         },
 246 };
 247 module_platform_driver(dw_mci_hi3798mv200_driver);
 248
 249 MODULE_DESCRIPTION("HiSilicon Hi3798MV200 Specific DW-MSHC Driver Extension");
 250 MODULE_LICENSE("GPL");