mmc/host/sdhci-spear.c

0001 /*
0002  * drivers/mmc/host/sdhci-spear.c
0003  *
0004  * Support of SDHCI platform devices for spear soc family
0005  *
0006  * Copyright (C) 2010 ST Microelectronics
0007  * Viresh Kumar <vireshk@kernel.org>
0008  *
0009  * Inspired by sdhci-pltfm.c
0010  *
0011  * This file is licensed under the terms of the GNU General Public
0012  * License version 2. This program is licensed "as is" without any
0013  * warranty of any kind, whether express or implied.
0014  */
0015
0016 #include <linux/clk.h>
0017 #include <linux/delay.h>
0018 #include <linux/highmem.h>
0019 #include <linux/module.h>
0020 #include <linux/interrupt.h>
0021 #include <linux/irq.h>
0022 #include <linux/of.h>
0023 #include <linux/platform_device.h>
0024 #include <linux/pm.h>
0025 #include <linux/slab.h>
0026 #include <linux/mmc/host.h>
0027 #include <linux/mmc/slot-gpio.h>
0028 #include <linux/io.h>
0029 #include "sdhci.h"
0030
0031 struct spear_sdhci {
0032     struct clk *clk;
0033 };
0034
0035 /* sdhci ops */
0036 static const struct sdhci_ops sdhci_pltfm_ops = {
0037     .set_clock = sdhci_set_clock,
0038     .set_bus_width = sdhci_set_bus_width,
0039     .reset = sdhci_reset,
0040     .set_uhs_signaling = sdhci_set_uhs_signaling,
0041 };
0042
0043 static int sdhci_probe(struct platform_device *pdev)
0044 {
0045     struct sdhci_host *host;
0046     struct spear_sdhci *sdhci;
0047     struct device *dev;
0048     int ret;
0049
0050     dev = pdev->dev.parent ? pdev->dev.parent : &pdev->dev;
0051     host = sdhci_alloc_host(dev, sizeof(*sdhci));
0052     if (IS_ERR(host)) {
0053         ret = PTR_ERR(host);
0054         dev_dbg(&pdev->dev, "cannot allocate memory for sdhci\n");
0055         goto err;
0056     }
0057
0058     host->ioaddr = devm_platform_ioremap_resource(pdev, 0);
0059     if (IS_ERR(host->ioaddr)) {
0060         ret = PTR_ERR(host->ioaddr);
0061         dev_dbg(&pdev->dev, "unable to map iomem: %d\n", ret);
0062         goto err_host;
0063     }
0064
0065     host->hw_name = "sdhci";
0066     host->ops = &sdhci_pltfm_ops;
0067     host->irq = platform_get_irq(pdev, 0);
0068     if (host->irq <= 0) {
0069         ret = -EINVAL;
0070         goto err_host;
0071     }
0072     host->quirks = SDHCI_QUIRK_BROKEN_ADMA;
0073
0074     sdhci = sdhci_priv(host);
0075
0076     /* clk enable */
0077     sdhci->clk = devm_clk_get(&pdev->dev, NULL);
0078     if (IS_ERR(sdhci->clk)) {
0079         ret = PTR_ERR(sdhci->clk);
0080         dev_dbg(&pdev->dev, "Error getting clock\n");
0081         goto err_host;
0082     }
0083
0084     ret = clk_prepare_enable(sdhci->clk);
0085     if (ret) {
0086         dev_dbg(&pdev->dev, "Error enabling clock\n");
0087         goto err_host;
0088     }
0089
0090     ret = clk_set_rate(sdhci->clk, 50000000);
0091     if (ret)
0092         dev_dbg(&pdev->dev, "Error setting desired clk, clk=%lu\n",
0093                 clk_get_rate(sdhci->clk));
0094
0095     /*
0096      * It is optional to use GPIOs for sdhci card detection. If we
0097      * find a descriptor using slot GPIO, we use it.
0098      */
0099     ret = mmc_gpiod_request_cd(host->mmc, "cd", 0, false, 0);
0100     if (ret == -EPROBE_DEFER)
0101         goto disable_clk;
0102
0103     ret = sdhci_add_host(host);
0104     if (ret)
0105         goto disable_clk;
0106
0107     platform_set_drvdata(pdev, host);
0108
0109     return 0;
0110
0111 disable_clk:
0112     clk_disable_unprepare(sdhci->clk);
0113 err_host:
0114     sdhci_free_host(host);
0115 err:
0116     dev_err(&pdev->dev, "spear-sdhci probe failed: %d\n", ret);
0117     return ret;
0118 }
0119
0120 static int sdhci_remove(struct platform_device *pdev)
0121 {
0122     struct sdhci_host *host = platform_get_drvdata(pdev);
0123     struct spear_sdhci *sdhci = sdhci_priv(host);
0124     int dead = 0;
0125     u32 scratch;
0126
0127     scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
0128     if (scratch == (u32)-1)
0129         dead = 1;
0130
0131     sdhci_remove_host(host, dead);
0132     clk_disable_unprepare(sdhci->clk);
0133     sdhci_free_host(host);
0134
0135     return 0;
0136 }
0137
0138 #ifdef CONFIG_PM_SLEEP
0139 static int sdhci_suspend(struct device *dev)
0140 {
0141     struct sdhci_host *host = dev_get_drvdata(dev);
0142     struct spear_sdhci *sdhci = sdhci_priv(host);
0143     int ret;
0144
0145     if (host->tuning_mode != SDHCI_TUNING_MODE_3)
0146         mmc_retune_needed(host->mmc);
0147
0148     ret = sdhci_suspend_host(host);
0149     if (!ret)
0150         clk_disable(sdhci->clk);
0151
0152     return ret;
0153 }
0154
0155 static int sdhci_resume(struct device *dev)
0156 {
0157     struct sdhci_host *host = dev_get_drvdata(dev);
0158     struct spear_sdhci *sdhci = sdhci_priv(host);
0159     int ret;
0160
0161     ret = clk_enable(sdhci->clk);
0162     if (ret) {
0163         dev_dbg(dev, "Resume: Error enabling clock\n");
0164         return ret;
0165     }
0166
0167     return sdhci_resume_host(host);
0168 }
0169 #endif
0170
0171 static SIMPLE_DEV_PM_OPS(sdhci_pm_ops, sdhci_suspend, sdhci_resume);
0172
0173 #ifdef CONFIG_OF
0174 static const struct of_device_id sdhci_spear_id_table[] = {
0175     { .compatible = "st,spear300-sdhci" },
0176     {}
0177 };
0178 MODULE_DEVICE_TABLE(of, sdhci_spear_id_table);
0179 #endif
0180
0181 static struct platform_driver sdhci_driver = {
0182     .driver = {
0183         .name   = "sdhci",
0184         .probe_type = PROBE_PREFER_ASYNCHRONOUS,
0185         .pm = &sdhci_pm_ops,
0186         .of_match_table = of_match_ptr(sdhci_spear_id_table),
0187     },
0188     .probe      = sdhci_probe,
0189     .remove     = sdhci_remove,
0190 };
0191
0192 module_platform_driver(sdhci_driver);
0193
0194 MODULE_DESCRIPTION("SPEAr Secure Digital Host Controller Interface driver");
0195 MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
0196 MODULE_LICENSE("GPL v2");