drivers/mmc/host/sdhci-of-at91.c

   1 /*
   2  * Atmel SDMMC controller driver.
   3  *
   4  * Copyright (C) 2015 Atmel,
   5  *               2015 Ludovic Desroches <ludovic.desroches@atmel.com>
   6  *
   7  * This software is licensed under the terms of the GNU General Public
   8  * License version 2, as published by the Free Software Foundation, and
   9  * may be copied, distributed, and modified under those terms.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/clk.h>
  18 #include <linux/err.h>
  19 #include <linux/io.h>
  20 #include <linux/mmc/host.h>
  21 #include <linux/mmc/slot-gpio.h>
  22 #include <linux/module.h>
  23 #include <linux/of.h>
  24 #include <linux/of_device.h>
  25 #include <linux/pm.h>
  26 #include <linux/pm_runtime.h>
  27
  28 #include "sdhci-pltfm.h"
  29
  30 #define SDMMC_CACR      0x230
  31 #define         SDMMC_CACR_CAPWREN      BIT(0)
  32 #define         SDMMC_CACR_KEY          (0x46 << 8)
  33
  34 struct sdhci_at91_priv {
  35         struct clk *hclock;
  36         struct clk *gck;
  37         struct clk *mainck;
  38 };
  39
  40 static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
  41         .set_clock              = sdhci_set_clock,
  42         .set_bus_width          = sdhci_set_bus_width,
  43         .reset                  = sdhci_reset,
  44         .set_uhs_signaling      = sdhci_set_uhs_signaling,
  45 };
  46
  47 static const struct sdhci_pltfm_data soc_data_sama5d2 = {
  48         .ops = &sdhci_at91_sama5d2_ops,
  49         .quirks2 = SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST,
  50 };
  51
  52 static const struct of_device_id sdhci_at91_dt_match[] = {
  53         { .compatible = "atmel,sama5d2-sdhci", .data = &soc_data_sama5d2 },
  54         {}
  55 };
  56
  57 #ifdef CONFIG_PM
  58 static int sdhci_at91_runtime_suspend(struct device *dev)
  59 {
  60         struct sdhci_host *host = dev_get_drvdata(dev);
  61         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
  62         struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
  63         int ret;
  64
  65         ret = sdhci_runtime_suspend_host(host);
  66
  67         clk_disable_unprepare(priv->gck);
  68         clk_disable_unprepare(priv->hclock);
  69         clk_disable_unprepare(priv->mainck);
  70
  71         return ret;
  72 }
  73
  74 static int sdhci_at91_runtime_resume(struct device *dev)
  75 {
  76         struct sdhci_host *host = dev_get_drvdata(dev);
  77         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
  78         struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
  79         int ret;
  80
  81         ret = clk_prepare_enable(priv->mainck);
  82         if (ret) {
  83                 dev_err(dev, "can't enable mainck\n");
  84                 return ret;
  85         }
  86
  87         ret = clk_prepare_enable(priv->hclock);
  88         if (ret) {
  89                 dev_err(dev, "can't enable hclock\n");
  90                 return ret;
  91         }
  92
  93         ret = clk_prepare_enable(priv->gck);
  94         if (ret) {
  95                 dev_err(dev, "can't enable gck\n");
  96                 return ret;
  97         }
  98
  99         return sdhci_runtime_resume_host(host);
 100 }
 101 #endif /* CONFIG_PM */
 102
 103 static const struct dev_pm_ops sdhci_at91_dev_pm_ops = {
 104         SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 105                                 pm_runtime_force_resume)
 106         SET_RUNTIME_PM_OPS(sdhci_at91_runtime_suspend,
 107                            sdhci_at91_runtime_resume,
 108                            NULL)
 109 };
 110
 111 static int sdhci_at91_probe(struct platform_device *pdev)
 112 {
 113         const struct of_device_id       *match;
 114         const struct sdhci_pltfm_data   *soc_data;
 115         struct sdhci_host               *host;
 116         struct sdhci_pltfm_host         *pltfm_host;
 117         struct sdhci_at91_priv          *priv;
 118         unsigned int                    caps0, caps1;
 119         unsigned int                    clk_base, clk_mul;
 120         unsigned int                    gck_rate, real_gck_rate;
 121         int                             ret;
 122
 123         match = of_match_device(sdhci_at91_dt_match, &pdev->dev);
 124         if (!match)
 125                 return -EINVAL;
 126         soc_data = match->data;
 127
 128         host = sdhci_pltfm_init(pdev, soc_data, sizeof(*priv));
 129         if (IS_ERR(host))
 130                 return PTR_ERR(host);
 131
 132         pltfm_host = sdhci_priv(host);
 133         priv = sdhci_pltfm_priv(pltfm_host);
 134
 135         priv->mainck = devm_clk_get(&pdev->dev, "baseclk");
 136         if (IS_ERR(priv->mainck)) {
 137                 dev_err(&pdev->dev, "failed to get baseclk\n");
 138                 return PTR_ERR(priv->mainck);
 139         }
 140
 141         priv->hclock = devm_clk_get(&pdev->dev, "hclock");
 142         if (IS_ERR(priv->hclock)) {
 143                 dev_err(&pdev->dev, "failed to get hclock\n");
 144                 return PTR_ERR(priv->hclock);
 145         }
 146
 147         priv->gck = devm_clk_get(&pdev->dev, "multclk");
 148         if (IS_ERR(priv->gck)) {
 149                 dev_err(&pdev->dev, "failed to get multclk\n");
 150                 return PTR_ERR(priv->gck);
 151         }
 152
 153         /*
 154          * The mult clock is provided by as a generated clock by the PMC
 155          * controller. In order to set the rate of gck, we have to get the
 156          * base clock rate and the clock mult from capabilities.
 157          */
 158         clk_prepare_enable(priv->hclock);
 159         caps0 = readl(host->ioaddr + SDHCI_CAPABILITIES);
 160         caps1 = readl(host->ioaddr + SDHCI_CAPABILITIES_1);
 161         clk_base = (caps0 & SDHCI_CLOCK_V3_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT;
 162         clk_mul = (caps1 & SDHCI_CLOCK_MUL_MASK) >> SDHCI_CLOCK_MUL_SHIFT;
 163         gck_rate = clk_base * 1000000 * (clk_mul + 1);
 164         ret = clk_set_rate(priv->gck, gck_rate);
 165         if (ret < 0) {
 166                 dev_err(&pdev->dev, "failed to set gck");
 167                 goto hclock_disable_unprepare;
 168         }
 169         /*
 170          * We need to check if we have the requested rate for gck because in
 171          * some cases this rate could be not supported. If it happens, the rate
 172          * is the closest one gck can provide. We have to update the value
 173          * of clk mul.
 174          */
 175         real_gck_rate = clk_get_rate(priv->gck);
 176         if (real_gck_rate != gck_rate) {
 177                 clk_mul = real_gck_rate / (clk_base * 1000000) - 1;
 178                 caps1 &= (~SDHCI_CLOCK_MUL_MASK);
 179                 caps1 |= ((clk_mul << SDHCI_CLOCK_MUL_SHIFT) & SDHCI_CLOCK_MUL_MASK);
 180                 /* Set capabilities in r/w mode. */
 181                 writel(SDMMC_CACR_KEY | SDMMC_CACR_CAPWREN, host->ioaddr + SDMMC_CACR);
 182                 writel(caps1, host->ioaddr + SDHCI_CAPABILITIES_1);
 183                 /* Set capabilities in ro mode. */
 184                 writel(0, host->ioaddr + SDMMC_CACR);
 185                 dev_info(&pdev->dev, "update clk mul to %u as gck rate is %u Hz\n",
 186                          clk_mul, real_gck_rate);
 187         }
 188
 189         clk_prepare_enable(priv->mainck);
 190         clk_prepare_enable(priv->gck);
 191
 192         ret = mmc_of_parse(host->mmc);
 193         if (ret)
 194                 goto clocks_disable_unprepare;
 195
 196         sdhci_get_of_property(pdev);
 197
 198         pm_runtime_get_noresume(&pdev->dev);
 199         pm_runtime_set_active(&pdev->dev);
 200         pm_runtime_enable(&pdev->dev);
 201         pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
 202         pm_runtime_use_autosuspend(&pdev->dev);
 203
 204         ret = sdhci_add_host(host);
 205         if (ret)
 206                 goto pm_runtime_disable;
 207
 208         /*
 209          * When calling sdhci_runtime_suspend_host(), the sdhci layer makes
 210          * the assumption that all the clocks of the controller are disabled.
 211          * It means we can't get irq from it when it is runtime suspended.
 212          * For that reason, it is not planned to wake-up on a card detect irq
 213          * from the controller.
 214          * If we want to use runtime PM and to be able to wake-up on card
 215          * insertion, we have to use a GPIO for the card detection or we can
 216          * use polling. Be aware that using polling will resume/suspend the
 217          * controller between each attempt.
 218          * Disable SDHCI_QUIRK_BROKEN_CARD_DETECTION to be sure nobody tries
 219          * to enable polling via device tree with broken-cd property.
 220          */
 221         if (!(host->mmc->caps & MMC_CAP_NONREMOVABLE) &&
 222             IS_ERR_VALUE(mmc_gpio_get_cd(host->mmc))) {
 223                 host->mmc->caps |= MMC_CAP_NEEDS_POLL;
 224                 host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
 225         }
 226
 227         pm_runtime_put_autosuspend(&pdev->dev);
 228
 229         return 0;
 230
 231 pm_runtime_disable:
 232         pm_runtime_disable(&pdev->dev);
 233         pm_runtime_set_suspended(&pdev->dev);
 234         pm_runtime_put_noidle(&pdev->dev);
 235 clocks_disable_unprepare:
 236         clk_disable_unprepare(priv->gck);
 237         clk_disable_unprepare(priv->mainck);
 238 hclock_disable_unprepare:
 239         clk_disable_unprepare(priv->hclock);
 240         sdhci_pltfm_free(pdev);
 241         return ret;
 242 }
 243
 244 static int sdhci_at91_remove(struct platform_device *pdev)
 245 {
 246         struct sdhci_host       *host = platform_get_drvdata(pdev);
 247         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 248         struct sdhci_at91_priv  *priv = sdhci_pltfm_priv(pltfm_host);
 249         struct clk *gck = priv->gck;
 250         struct clk *hclock = priv->hclock;
 251         struct clk *mainck = priv->mainck;
 252
 253         pm_runtime_get_sync(&pdev->dev);
 254         pm_runtime_disable(&pdev->dev);
 255         pm_runtime_put_noidle(&pdev->dev);
 256
 257         sdhci_pltfm_unregister(pdev);
 258
 259         clk_disable_unprepare(gck);
 260         clk_disable_unprepare(hclock);
 261         clk_disable_unprepare(mainck);
 262
 263         return 0;
 264 }
 265
 266 static struct platform_driver sdhci_at91_driver = {
 267         .driver         = {
 268                 .name   = "sdhci-at91",
 269                 .of_match_table = sdhci_at91_dt_match,
 270                 .pm     = &sdhci_at91_dev_pm_ops,
 271         },
 272         .probe          = sdhci_at91_probe,
 273         .remove         = sdhci_at91_remove,
 274 };
 275
 276 module_platform_driver(sdhci_at91_driver);
 277
 278 MODULE_DESCRIPTION("SDHCI driver for at91");
 279 MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches@atmel.com>");
 280 MODULE_LICENSE("GPL v2");