drivers/mmc/host/dw_mmc-starfive.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright 2022 StarFive, Inc <clivia.cai@starfivetech.com>
   4  *
   5  * THE PRESENT SOFTWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING
   6  * CUSTOMERS WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER
   7  * FOR THEM TO SAVE TIME. AS A RESULT, STARFIVE SHALL NOT BE HELD LIABLE
   8  * FOR ANY DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY
   9  * CLAIMS ARISING FROM THE CONTENT OF SUCH SOFTWARE AND/OR THE USE MADE
  10  * BY CUSTOMERS OF THE CODING INFORMATION CONTAINED HEREIN IN CONNECTION
  11  * WITH THEIR PRODUCTS.
  12  */
  13
  14
  15 #include <linux/clk.h>
  16 #include <linux/mfd/syscon.h>
  17 #include <linux/mmc/host.h>
  18 #include <linux/module.h>
  19 #include <linux/of_address.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/pm_runtime.h>
  22 #include <linux/regmap.h>
  23 #include <linux/regulator/consumer.h>
  24 #include <linux/gpio.h>
  25 #include <linux/delay.h>
  26
  27 #include "dw_mmc.h"
  28 #include "dw_mmc-pltfm.h"
  29
  30 #define ALL_INT_CLR             0x1ffff
  31 #define MAX_DELAY_CHAIN         32
  32 struct starfive_priv {
  33         struct device *dev;
  34         struct regmap *reg_syscon;
  35         u32 syscon_offset;
  36         u32 syscon_shift;
  37         u32 syscon_mask;
  38 };
  39
  40 static unsigned long dw_mci_starfive_caps[] = {
  41         MMC_CAP_CMD23,
  42         MMC_CAP_CMD23,
  43         MMC_CAP_CMD23
  44 };
  45
  46 static void dw_mci_starfive_set_ios(struct dw_mci *host, struct mmc_ios *ios)
  47 {
  48         int ret;
  49         unsigned int clock;
  50
  51         if (ios->timing == MMC_TIMING_MMC_DDR52 || ios->timing == MMC_TIMING_UHS_DDR50) {
  52                 clock = (ios->clock > 50000000 && ios->clock <= 52000000) ? 100000000 : ios->clock;
  53                 ret = clk_set_rate(host->ciu_clk, clock);
  54                 if (ret)
  55                         dev_dbg(host->dev, "Use an external frequency divider %uHz\n", ios->clock);
  56                 host->bus_hz = clk_get_rate(host->ciu_clk);
  57         } else {
  58                 dev_dbg(host->dev, "Using the internal divider\n");
  59         }
  60 }
  61
  62 static int dw_mci_starfive_execute_tuning(struct dw_mci_slot *slot,
  63                                              u32 opcode)
  64 {
  65         static const int grade  = MAX_DELAY_CHAIN;
  66         struct dw_mci *host = slot->host;
  67         struct starfive_priv *priv = host->priv;
  68         int raise_point = -1, fall_point = -1;
  69         int err, prev_err = -1;
  70         int found = 0;
  71         int i;
  72         u32 regval;
  73
  74         for (i = 0; i < grade; i++) {
  75                 regval = i << priv->syscon_shift;
  76                 err = regmap_update_bits(priv->reg_syscon, priv->syscon_offset, priv->syscon_mask, regval);
  77                 if (err)
  78                         return err;
  79                 mci_writel(host, RINTSTS, ALL_INT_CLR);
  80
  81                 err = mmc_send_tuning(slot->mmc, opcode, NULL);
  82                 if (!err)
  83                         found = 1;
  84
  85                 if (i > 0) {
  86                         if (err && !prev_err)
  87                                 fall_point = i - 1;
  88                         if (!err && prev_err)
  89                                 raise_point = i;
  90                 }
  91
  92                 if (raise_point != -1 && fall_point != -1)
  93                         goto tuning_out;
  94
  95                 prev_err = err;
  96                 err = 0;
  97         }
  98
  99 tuning_out:
 100         if (found) {
 101                 if (raise_point == -1)
 102                         raise_point = 0;
 103                 if (fall_point == -1)
 104                         fall_point = grade - 1;
 105                 if (fall_point < raise_point) {
 106                         if ((raise_point + fall_point) >
 107                             (grade - 1))
 108                                 i = fall_point / 2;
 109                         else
 110                                 i = (raise_point + grade - 1) / 2;
 111                 } else {
 112                         i = (raise_point + fall_point) / 2;
 113                 }
 114
 115                 regval = i << priv->syscon_shift;
 116                 err = regmap_update_bits(priv->reg_syscon, priv->syscon_offset, priv->syscon_mask, regval);
 117                 if (err)
 118                         return err;
 119                 dev_dbg(host->dev, "Found valid delay chain! use it [delay=%d]\n", i);
 120         } else {
 121                 dev_err(host->dev, "No valid delay chain! use default\n");
 122                 err = -EINVAL;
 123         }
 124
 125         mci_writel(host, RINTSTS, ALL_INT_CLR);
 126         return err;
 127 }
 128
 129 static int dw_mci_starfive_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
 130 {
 131
 132         struct dw_mci_slot *slot = mmc_priv(mmc);
 133         struct dw_mci *host = slot->host;
 134         u32 ret;
 135
 136         if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
 137                 ret = gpio_direction_output(25, 0);
 138         else if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180)
 139                 ret = gpio_direction_output(25, 1);
 140         if (ret)
 141                 return ret;
 142
 143         if (!IS_ERR(mmc->supply.vqmmc)) {
 144                 ret = mmc_regulator_set_vqmmc(mmc, ios);
 145                 if (ret < 0) {
 146                         dev_err(host->dev, "Regulator set error %d\n", ret);
 147                         return ret;
 148                 }
 149         }
 150
 151         /* We should delay 20ms wait for timing setting finished. */
 152         mdelay(20);
 153         return 0;
 154 }
 155
 156 static int dw_mci_starfive_parse_dt(struct dw_mci *host)
 157 {
 158         struct of_phandle_args args;
 159         struct starfive_priv *priv;
 160         int ret;
 161
 162         priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
 163         if (!priv)
 164                 return -ENOMEM;
 165
 166         ret = of_parse_phandle_with_fixed_args(host->dev->of_node,
 167                                                 "starfive,sys-syscon", 3, 0, &args);
 168         if (ret) {
 169                 dev_err(host->dev, "Failed to parse starfive,sys-syscon\n");
 170                 return -EINVAL;
 171         }
 172
 173         priv->reg_syscon = syscon_node_to_regmap(args.np);
 174         of_node_put(args.np);
 175         if (IS_ERR(priv->reg_syscon))
 176                 return PTR_ERR(priv->reg_syscon);
 177
 178         priv->syscon_offset = args.args[0];
 179         priv->syscon_shift  = args.args[1];
 180         priv->syscon_mask   = args.args[2];
 181
 182         host->priv = priv;
 183
 184         return 0;
 185 }
 186
 187 static const struct dw_mci_drv_data starfive_data = {
 188         .caps = dw_mci_starfive_caps,
 189         .num_caps = ARRAY_SIZE(dw_mci_starfive_caps),
 190         .set_ios = dw_mci_starfive_set_ios,
 191         .parse_dt = dw_mci_starfive_parse_dt,
 192         .execute_tuning = dw_mci_starfive_execute_tuning,
 193         .switch_voltage  = dw_mci_starfive_switch_voltage,
 194 };
 195
 196 static int dw_mci_starfive_probe(struct platform_device *pdev)
 197 {
 198         return dw_mci_pltfm_register(pdev, &starfive_data);
 199 }
 200
 201 static int dw_mci_starfive_remove(struct platform_device *pdev)
 202 {
 203         return dw_mci_pltfm_remove(pdev);
 204 }
 205
 206 static const struct of_device_id dw_mci_starfive_match[] = {
 207         { .compatible = "starfive,jh7110-sdio", },
 208         {},
 209 };
 210
 211 MODULE_DEVICE_TABLE(of, dw_mci_starfive_match);
 212 static struct platform_driver dw_mci_starfive_driver = {
 213         .probe = dw_mci_starfive_probe,
 214         .remove = dw_mci_starfive_remove,
 215         .driver = {
 216                 .name = "dwmmc_starfive",
 217                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 218                 .of_match_table = dw_mci_starfive_match,
 219         },
 220 };
 221 module_platform_driver(dw_mci_starfive_driver);
 222
 223 MODULE_DESCRIPTION("StarFive JH7110 Specific DW-MSHC Driver Extension");
 224 MODULE_LICENSE("GPL v2");
 225 MODULE_ALIAS("platform:dwmmc_starfive");