drivers/mmc/host/dw_mmc-rockchip.c

   1 /*
   2  * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/clk.h>
  13 #include <linux/mmc/host.h>
  14 #include <linux/mmc/dw_mmc.h>
  15 #include <linux/of_address.h>
  16 #include <linux/slab.h>
  17
  18 #include "dw_mmc.h"
  19 #include "dw_mmc-pltfm.h"
  20
  21 #define RK3288_CLKGEN_DIV       2
  22
  23 struct dw_mci_rockchip_priv_data {
  24         struct clk              *drv_clk;
  25         struct clk              *sample_clk;
  26         int                     default_sample_phase;
  27 };
  28
  29 static void dw_mci_rockchip_prepare_command(struct dw_mci *host, u32 *cmdr)
  30 {
  31         *cmdr |= SDMMC_CMD_USE_HOLD_REG;
  32 }
  33
  34 static int dw_mci_rk3288_setup_clock(struct dw_mci *host)
  35 {
  36         host->bus_hz /= RK3288_CLKGEN_DIV;
  37
  38         return 0;
  39 }
  40
  41 static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios)
  42 {
  43         struct dw_mci_rockchip_priv_data *priv = host->priv;
  44         int ret;
  45         unsigned int cclkin;
  46         u32 bus_hz;
  47
  48         if (ios->clock == 0)
  49                 return;
  50
  51         /*
  52          * cclkin: source clock of mmc controller
  53          * bus_hz: card interface clock generated by CLKGEN
  54          * bus_hz = cclkin / RK3288_CLKGEN_DIV
  55          * ios->clock = (div == 0) ? bus_hz : (bus_hz / (2 * div))
  56          *
  57          * Note: div can only be 0 or 1
  58          *       if DDR50 8bit mode(only emmc work in 8bit mode),
  59          *       div must be set 1
  60          */
  61         if (ios->bus_width == MMC_BUS_WIDTH_8 &&
  62             ios->timing == MMC_TIMING_MMC_DDR52)
  63                 cclkin = 2 * ios->clock * RK3288_CLKGEN_DIV;
  64         else
  65                 cclkin = ios->clock * RK3288_CLKGEN_DIV;
  66
  67         ret = clk_set_rate(host->ciu_clk, cclkin);
  68         if (ret)
  69                 dev_warn(host->dev, "failed to set rate %uHz\n", ios->clock);
  70
  71         bus_hz = clk_get_rate(host->ciu_clk) / RK3288_CLKGEN_DIV;
  72         if (bus_hz != host->bus_hz) {
  73                 host->bus_hz = bus_hz;
  74                 /* force dw_mci_setup_bus() */
  75                 host->current_speed = 0;
  76         }
  77
  78         /* Make sure we use phases which we can enumerate with */
  79         if (!IS_ERR(priv->sample_clk))
  80                 clk_set_phase(priv->sample_clk, priv->default_sample_phase);
  81 }
  82
  83 #define NUM_PHASES                      360
  84 #define TUNING_ITERATION_TO_PHASE(i)    (DIV_ROUND_UP((i) * 360, NUM_PHASES))
  85
  86 static int dw_mci_rk3288_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
  87 {
  88         struct dw_mci *host = slot->host;
  89         struct dw_mci_rockchip_priv_data *priv = host->priv;
  90         struct mmc_host *mmc = slot->mmc;
  91         int ret = 0;
  92         int i;
  93         bool v, prev_v = 0, first_v;
  94         struct range_t {
  95                 int start;
  96                 int end; /* inclusive */
  97         };
  98         struct range_t *ranges;
  99         unsigned int range_count = 0;
 100         int longest_range_len = -1;
 101         int longest_range = -1;
 102         int middle_phase;
 103
 104         if (IS_ERR(priv->sample_clk)) {
 105                 dev_err(host->dev, "Tuning clock (sample_clk) not defined.\n");
 106                 return -EIO;
 107         }
 108
 109         ranges = kmalloc_array(NUM_PHASES / 2 + 1, sizeof(*ranges), GFP_KERNEL);
 110         if (!ranges)
 111                 return -ENOMEM;
 112
 113         /* Try each phase and extract good ranges */
 114         for (i = 0; i < NUM_PHASES; ) {
 115                 clk_set_phase(priv->sample_clk, TUNING_ITERATION_TO_PHASE(i));
 116
 117                 v = !mmc_send_tuning(mmc, opcode, NULL);
 118
 119                 if (i == 0)
 120                         first_v = v;
 121
 122                 if ((!prev_v) && v) {
 123                         range_count++;
 124                         ranges[range_count-1].start = i;
 125                 }
 126                 if (v) {
 127                         ranges[range_count-1].end = i;
 128                         i++;
 129                 } else if (i == NUM_PHASES - 1) {
 130                         /* No extra skipping rules if we're at the end */
 131                         i++;
 132                 } else {
 133                         /*
 134                          * No need to check too close to an invalid
 135                          * one since testing bad phases is slow.  Skip
 136                          * 20 degrees.
 137                          */
 138                         i += DIV_ROUND_UP(20 * NUM_PHASES, 360);
 139
 140                         /* Always test the last one */
 141                         if (i >= NUM_PHASES)
 142                                 i = NUM_PHASES - 1;
 143                 }
 144
 145                 prev_v = v;
 146         }
 147
 148         if (range_count == 0) {
 149                 dev_warn(host->dev, "All phases bad!");
 150                 ret = -EIO;
 151                 goto free;
 152         }
 153
 154         /* wrap around case, merge the end points */
 155         if ((range_count > 1) && first_v && v) {
 156                 ranges[0].start = ranges[range_count-1].start;
 157                 range_count--;
 158         }
 159
 160         if (ranges[0].start == 0 && ranges[0].end == NUM_PHASES - 1) {
 161                 clk_set_phase(priv->sample_clk, priv->default_sample_phase);
 162                 dev_info(host->dev, "All phases work, using default phase %d.",
 163                          priv->default_sample_phase);
 164                 goto free;
 165         }
 166
 167         /* Find the longest range */
 168         for (i = 0; i < range_count; i++) {
 169                 int len = (ranges[i].end - ranges[i].start + 1);
 170
 171                 if (len < 0)
 172                         len += NUM_PHASES;
 173
 174                 if (longest_range_len < len) {
 175                         longest_range_len = len;
 176                         longest_range = i;
 177                 }
 178
 179                 dev_dbg(host->dev, "Good phase range %d-%d (%d len)\n",
 180                         TUNING_ITERATION_TO_PHASE(ranges[i].start),
 181                         TUNING_ITERATION_TO_PHASE(ranges[i].end),
 182                         len
 183                 );
 184         }
 185
 186         dev_dbg(host->dev, "Best phase range %d-%d (%d len)\n",
 187                 TUNING_ITERATION_TO_PHASE(ranges[longest_range].start),
 188                 TUNING_ITERATION_TO_PHASE(ranges[longest_range].end),
 189                 longest_range_len
 190         );
 191
 192         middle_phase = ranges[longest_range].start + longest_range_len / 2;
 193         middle_phase %= NUM_PHASES;
 194         dev_info(host->dev, "Successfully tuned phase to %d\n",
 195                  TUNING_ITERATION_TO_PHASE(middle_phase));
 196
 197         clk_set_phase(priv->sample_clk,
 198                       TUNING_ITERATION_TO_PHASE(middle_phase));
 199
 200 free:
 201         kfree(ranges);
 202         return ret;
 203 }
 204
 205 static int dw_mci_rk3288_parse_dt(struct dw_mci *host)
 206 {
 207         struct device_node *np = host->dev->of_node;
 208         struct dw_mci_rockchip_priv_data *priv;
 209
 210         priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
 211         if (!priv)
 212                 return -ENOMEM;
 213
 214         if (of_property_read_u32(np, "rockchip,default-sample-phase",
 215                                         &priv->default_sample_phase))
 216                 priv->default_sample_phase = 0;
 217
 218         priv->drv_clk = devm_clk_get(host->dev, "ciu-drive");
 219         if (IS_ERR(priv->drv_clk))
 220                 dev_dbg(host->dev, "ciu_drv not available\n");
 221
 222         priv->sample_clk = devm_clk_get(host->dev, "ciu-sample");
 223         if (IS_ERR(priv->sample_clk))
 224                 dev_dbg(host->dev, "ciu_sample not available\n");
 225
 226         host->priv = priv;
 227
 228         return 0;
 229 }
 230
 231 static int dw_mci_rockchip_init(struct dw_mci *host)
 232 {
 233         /* It is slot 8 on Rockchip SoCs */
 234         host->sdio_id0 = 8;
 235
 236         /* It needs this quirk on all Rockchip SoCs */
 237         host->pdata->quirks |= DW_MCI_QUIRK_BROKEN_DTO;
 238
 239         return 0;
 240 }
 241
 242 /* Common capabilities of RK3288 SoC */
 243 static unsigned long dw_mci_rk3288_dwmmc_caps[4] = {
 244         MMC_CAP_RUNTIME_RESUME, /* emmc */
 245         MMC_CAP_RUNTIME_RESUME, /* sdmmc */
 246         MMC_CAP_RUNTIME_RESUME, /* sdio0 */
 247         MMC_CAP_RUNTIME_RESUME, /* sdio1 */
 248 };
 249 static const struct dw_mci_drv_data rk2928_drv_data = {
 250         .prepare_command        = dw_mci_rockchip_prepare_command,
 251         .init                   = dw_mci_rockchip_init,
 252 };
 253
 254 static const struct dw_mci_drv_data rk3288_drv_data = {
 255         .caps                   = dw_mci_rk3288_dwmmc_caps,
 256         .prepare_command        = dw_mci_rockchip_prepare_command,
 257         .set_ios                = dw_mci_rk3288_set_ios,
 258         .execute_tuning         = dw_mci_rk3288_execute_tuning,
 259         .parse_dt               = dw_mci_rk3288_parse_dt,
 260         .setup_clock    = dw_mci_rk3288_setup_clock,
 261         .init                   = dw_mci_rockchip_init,
 262 };
 263
 264 static const struct of_device_id dw_mci_rockchip_match[] = {
 265         { .compatible = "rockchip,rk2928-dw-mshc",
 266                 .data = &rk2928_drv_data },
 267         { .compatible = "rockchip,rk3288-dw-mshc",
 268                 .data = &rk3288_drv_data },
 269         {},
 270 };
 271 MODULE_DEVICE_TABLE(of, dw_mci_rockchip_match);
 272
 273 static int dw_mci_rockchip_probe(struct platform_device *pdev)
 274 {
 275         const struct dw_mci_drv_data *drv_data;
 276         const struct of_device_id *match;
 277
 278         if (!pdev->dev.of_node)
 279                 return -ENODEV;
 280
 281         match = of_match_node(dw_mci_rockchip_match, pdev->dev.of_node);
 282         drv_data = match->data;
 283
 284         return dw_mci_pltfm_register(pdev, drv_data);
 285 }
 286
 287 #ifdef CONFIG_PM_SLEEP
 288 static int dw_mci_rockchip_suspend(struct device *dev)
 289 {
 290         struct dw_mci *host = dev_get_drvdata(dev);
 291
 292         return dw_mci_suspend(host);
 293 }
 294
 295 static int dw_mci_rockchip_resume(struct device *dev)
 296 {
 297         struct dw_mci *host = dev_get_drvdata(dev);
 298
 299         return dw_mci_resume(host);
 300 }
 301 #endif /* CONFIG_PM_SLEEP */
 302
 303 static SIMPLE_DEV_PM_OPS(dw_mci_rockchip_pmops,
 304                          dw_mci_rockchip_suspend,
 305                          dw_mci_rockchip_resume);
 306
 307 static struct platform_driver dw_mci_rockchip_pltfm_driver = {
 308         .probe          = dw_mci_rockchip_probe,
 309         .remove         = dw_mci_pltfm_remove,
 310         .driver         = {
 311                 .name           = "dwmmc_rockchip",
 312                 .of_match_table = dw_mci_rockchip_match,
 313                 .pm             = &dw_mci_rockchip_pmops,
 314         },
 315 };
 316
 317 module_platform_driver(dw_mci_rockchip_pltfm_driver);
 318
 319 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
 320 MODULE_DESCRIPTION("Rockchip Specific DW-MSHC Driver Extension");
 321 MODULE_ALIAS("platform:dwmmc_rockchip");
 322 MODULE_LICENSE("GPL v2");