drivers/mmc/host/sdhci-sirf.c

   1 /*
   2  * SDHCI support for SiRF primaII and marco SoCs
   3  *
   4  * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
   5  *
   6  * Licensed under GPLv2 or later.
   7  */
   8
   9 #include <linux/delay.h>
  10 #include <linux/device.h>
  11 #include <linux/mmc/host.h>
  12 #include <linux/module.h>
  13 #include <linux/of.h>
  14 #include <linux/of_gpio.h>
  15 #include <linux/mmc/slot-gpio.h>
  16 #include "sdhci-pltfm.h"
  17
  18 #define SDHCI_CLK_DELAY_SETTING 0x4C
  19 #define SDHCI_SIRF_8BITBUS BIT(3)
  20 #define SIRF_TUNING_COUNT 16384
  21
  22 struct sdhci_sirf_priv {
  23         int gpio_cd;
  24 };
  25
  26 static void sdhci_sirf_set_bus_width(struct sdhci_host *host, int width)
  27 {
  28         u8 ctrl;
  29
  30         ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
  31         ctrl &= ~(SDHCI_CTRL_4BITBUS | SDHCI_SIRF_8BITBUS);
  32
  33         /*
  34          * CSR atlas7 and prima2 SD host version is not 3.0
  35          * 8bit-width enable bit of CSR SD hosts is 3,
  36          * while stardard hosts use bit 5
  37          */
  38         if (width == MMC_BUS_WIDTH_8)
  39                 ctrl |= SDHCI_SIRF_8BITBUS;
  40         else if (width == MMC_BUS_WIDTH_4)
  41                 ctrl |= SDHCI_CTRL_4BITBUS;
  42
  43         sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
  44 }
  45
  46 static u32 sdhci_sirf_readl_le(struct sdhci_host *host, int reg)
  47 {
  48         u32 val = readl(host->ioaddr + reg);
  49
  50         if (unlikely((reg == SDHCI_CAPABILITIES_1) &&
  51                         (host->mmc->caps & MMC_CAP_UHS_SDR50))) {
  52                 /* fake CAP_1 register */
  53                 val = SDHCI_SUPPORT_DDR50 |
  54                         SDHCI_SUPPORT_SDR50 | SDHCI_USE_SDR50_TUNING;
  55         }
  56
  57         if (unlikely(reg == SDHCI_SLOT_INT_STATUS)) {
  58                 u32 prss = val;
  59                 /* fake chips as V3.0 host conreoller */
  60                 prss &= ~(0xFF << 16);
  61                 val = prss | (SDHCI_SPEC_300 << 16);
  62         }
  63         return val;
  64 }
  65
  66 static u16 sdhci_sirf_readw_le(struct sdhci_host *host, int reg)
  67 {
  68         u16 ret = 0;
  69
  70         ret = readw(host->ioaddr + reg);
  71
  72         if (unlikely(reg == SDHCI_HOST_VERSION)) {
  73                 ret = readw(host->ioaddr + SDHCI_HOST_VERSION);
  74                 ret |= SDHCI_SPEC_300;
  75         }
  76
  77         return ret;
  78 }
  79
  80 static int sdhci_sirf_execute_tuning(struct sdhci_host *host, u32 opcode)
  81 {
  82         int tuning_seq_cnt = 3;
  83         int phase;
  84         u8 tuned_phase_cnt = 0;
  85         int rc = 0, longest_range = 0;
  86         int start = -1, end = 0, tuning_value = -1, range = 0;
  87         u16 clock_setting;
  88         struct mmc_host *mmc = host->mmc;
  89
  90         clock_setting = sdhci_readw(host, SDHCI_CLK_DELAY_SETTING);
  91         clock_setting &= ~0x3fff;
  92
  93 retry:
  94         phase = 0;
  95         tuned_phase_cnt = 0;
  96         do {
  97                 sdhci_writel(host,
  98                         clock_setting | phase,
  99                         SDHCI_CLK_DELAY_SETTING);
 100
 101                 if (!mmc_send_tuning(mmc, opcode, NULL)) {
 102                         /* Tuning is successful at this tuning point */
 103                         tuned_phase_cnt++;
 104                         dev_dbg(mmc_dev(mmc), "%s: Found good phase = %d\n",
 105                                  mmc_hostname(mmc), phase);
 106                         if (start == -1)
 107                                 start = phase;
 108                         end = phase;
 109                         range++;
 110                         if (phase == (SIRF_TUNING_COUNT - 1)
 111                                 && range > longest_range)
 112                                 tuning_value = (start + end) / 2;
 113                 } else {
 114                         dev_dbg(mmc_dev(mmc), "%s: Found bad phase = %d\n",
 115                                  mmc_hostname(mmc), phase);
 116                         if (range > longest_range) {
 117                                 tuning_value = (start + end) / 2;
 118                                 longest_range = range;
 119                         }
 120                         start = -1;
 121                         end = range = 0;
 122                 }
 123         } while (++phase < SIRF_TUNING_COUNT);
 124
 125         if (tuned_phase_cnt && tuning_value > 0) {
 126                 /*
 127                  * Finally set the selected phase in delay
 128                  * line hw block.
 129                  */
 130                 phase = tuning_value;
 131                 sdhci_writel(host,
 132                         clock_setting | phase,
 133                         SDHCI_CLK_DELAY_SETTING);
 134
 135                 dev_dbg(mmc_dev(mmc), "%s: Setting the tuning phase to %d\n",
 136                          mmc_hostname(mmc), phase);
 137         } else {
 138                 if (--tuning_seq_cnt)
 139                         goto retry;
 140                 /* Tuning failed */
 141                 dev_dbg(mmc_dev(mmc), "%s: No tuning point found\n",
 142                        mmc_hostname(mmc));
 143                 rc = -EIO;
 144         }
 145
 146         return rc;
 147 }
 148
 149 static struct sdhci_ops sdhci_sirf_ops = {
 150         .read_l = sdhci_sirf_readl_le,
 151         .read_w = sdhci_sirf_readw_le,
 152         .platform_execute_tuning = sdhci_sirf_execute_tuning,
 153         .set_clock = sdhci_set_clock,
 154         .get_max_clock  = sdhci_pltfm_clk_get_max_clock,
 155         .set_bus_width = sdhci_sirf_set_bus_width,
 156         .reset = sdhci_reset,
 157         .set_uhs_signaling = sdhci_set_uhs_signaling,
 158 };
 159
 160 static struct sdhci_pltfm_data sdhci_sirf_pdata = {
 161         .ops = &sdhci_sirf_ops,
 162         .quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
 163                 SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
 164                 SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
 165                 SDHCI_QUIRK_RESET_CMD_DATA_ON_IOS,
 166         .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
 167 };
 168
 169 static int sdhci_sirf_probe(struct platform_device *pdev)
 170 {
 171         struct sdhci_host *host;
 172         struct sdhci_pltfm_host *pltfm_host;
 173         struct sdhci_sirf_priv *priv;
 174         struct clk *clk;
 175         int gpio_cd;
 176         int ret;
 177
 178         clk = devm_clk_get(&pdev->dev, NULL);
 179         if (IS_ERR(clk)) {
 180                 dev_err(&pdev->dev, "unable to get clock");
 181                 return PTR_ERR(clk);
 182         }
 183
 184         if (pdev->dev.of_node)
 185                 gpio_cd = of_get_named_gpio(pdev->dev.of_node, "cd-gpios", 0);
 186         else
 187                 gpio_cd = -EINVAL;
 188
 189         host = sdhci_pltfm_init(pdev, &sdhci_sirf_pdata, sizeof(struct sdhci_sirf_priv));
 190         if (IS_ERR(host))
 191                 return PTR_ERR(host);
 192
 193         pltfm_host = sdhci_priv(host);
 194         pltfm_host->clk = clk;
 195         priv = sdhci_pltfm_priv(pltfm_host);
 196         priv->gpio_cd = gpio_cd;
 197
 198         sdhci_get_of_property(pdev);
 199
 200         ret = clk_prepare_enable(pltfm_host->clk);
 201         if (ret)
 202                 goto err_clk_prepare;
 203
 204         ret = sdhci_add_host(host);
 205         if (ret)
 206                 goto err_sdhci_add;
 207
 208         /*
 209          * We must request the IRQ after sdhci_add_host(), as the tasklet only
 210          * gets setup in sdhci_add_host() and we oops.
 211          */
 212         if (gpio_is_valid(priv->gpio_cd)) {
 213                 ret = mmc_gpio_request_cd(host->mmc, priv->gpio_cd, 0);
 214                 if (ret) {
 215                         dev_err(&pdev->dev, "card detect irq request failed: %d\n",
 216                                 ret);
 217                         goto err_request_cd;
 218                 }
 219                 mmc_gpiod_request_cd_irq(host->mmc);
 220         }
 221
 222         return 0;
 223
 224 err_request_cd:
 225         sdhci_remove_host(host, 0);
 226 err_sdhci_add:
 227         clk_disable_unprepare(pltfm_host->clk);
 228 err_clk_prepare:
 229         sdhci_pltfm_free(pdev);
 230         return ret;
 231 }
 232
 233 #ifdef CONFIG_PM_SLEEP
 234 static int sdhci_sirf_suspend(struct device *dev)
 235 {
 236         struct sdhci_host *host = dev_get_drvdata(dev);
 237         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 238         int ret;
 239
 240         ret = sdhci_suspend_host(host);
 241         if (ret)
 242                 return ret;
 243
 244         clk_disable(pltfm_host->clk);
 245
 246         return 0;
 247 }
 248
 249 static int sdhci_sirf_resume(struct device *dev)
 250 {
 251         struct sdhci_host *host = dev_get_drvdata(dev);
 252         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 253         int ret;
 254
 255         ret = clk_enable(pltfm_host->clk);
 256         if (ret) {
 257                 dev_dbg(dev, "Resume: Error enabling clock\n");
 258                 return ret;
 259         }
 260
 261         return sdhci_resume_host(host);
 262 }
 263
 264 static SIMPLE_DEV_PM_OPS(sdhci_sirf_pm_ops, sdhci_sirf_suspend, sdhci_sirf_resume);
 265 #endif
 266
 267 static const struct of_device_id sdhci_sirf_of_match[] = {
 268         { .compatible = "sirf,prima2-sdhc" },
 269         { }
 270 };
 271 MODULE_DEVICE_TABLE(of, sdhci_sirf_of_match);
 272
 273 static struct platform_driver sdhci_sirf_driver = {
 274         .driver         = {
 275                 .name   = "sdhci-sirf",
 276                 .of_match_table = sdhci_sirf_of_match,
 277 #ifdef CONFIG_PM_SLEEP
 278                 .pm     = &sdhci_sirf_pm_ops,
 279 #endif
 280         },
 281         .probe          = sdhci_sirf_probe,
 282         .remove         = sdhci_pltfm_unregister,
 283 };
 284
 285 module_platform_driver(sdhci_sirf_driver);
 286
 287 MODULE_DESCRIPTION("SDHCI driver for SiRFprimaII/SiRFmarco");
 288 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 289 MODULE_LICENSE("GPL v2");