sdhci-spear.c

  1/*
  2 * drivers/mmc/host/sdhci-spear.c
  3 *
  4 * Support of SDHCI platform devices for spear soc family
  5 *
  6 * Copyright (C) 2010 ST Microelectronics
  7 * Viresh Kumar <vireshk@kernel.org>
  8 *
  9 * Inspired by sdhci-pltfm.c
 10 *
 11 * This file is licensed under the terms of the GNU General Public
 12 * License version 2. This program is licensed "as is" without any
 13 * warranty of any kind, whether express or implied.
 14 */
 15
 16#include <linux/clk.h>
 17#include <linux/delay.h>
 18#include <linux/highmem.h>
 19#include <linux/module.h>
 20#include <linux/interrupt.h>
 21#include <linux/irq.h>
 22#include <linux/of.h>
 23#include <linux/platform_device.h>
 24#include <linux/pm.h>
 25#include <linux/slab.h>
 26#include <linux/mmc/host.h>
 27#include <linux/mmc/slot-gpio.h>
 28#include <linux/io.h>
 29#include "sdhci.h"
 30
 31struct spear_sdhci {
 32	struct clk *clk;
 33};
 34
 35/* sdhci ops */
 36static const struct sdhci_ops sdhci_pltfm_ops = {
 37	.set_clock = sdhci_set_clock,
 38	.set_bus_width = sdhci_set_bus_width,
 39	.reset = sdhci_reset,
 40	.set_uhs_signaling = sdhci_set_uhs_signaling,
 41};
 42
 43static int sdhci_probe(struct platform_device *pdev)
 44{
 45	struct sdhci_host *host;
 46	struct spear_sdhci *sdhci;
 47	struct device *dev;
 48	int ret;
 49
 50	dev = pdev->dev.parent ? pdev->dev.parent : &pdev->dev;
 51	host = sdhci_alloc_host(dev, sizeof(*sdhci));
 52	if (IS_ERR(host)) {
 53		ret = PTR_ERR(host);
 54		dev_dbg(&pdev->dev, "cannot allocate memory for sdhci\n");
 55		goto err;
 56	}
 57
 58	host->ioaddr = devm_platform_ioremap_resource(pdev, 0);
 59	if (IS_ERR(host->ioaddr)) {
 60		ret = PTR_ERR(host->ioaddr);
 61		dev_dbg(&pdev->dev, "unable to map iomem: %d\n", ret);
 62		goto err;
 63	}
 64
 65	host->hw_name = "sdhci";
 66	host->ops = &sdhci_pltfm_ops;
 67	host->irq = platform_get_irq(pdev, 0);
 68	if (host->irq < 0) {
 69		ret = host->irq;
 70		goto err;
 71	}
 72	host->quirks = SDHCI_QUIRK_BROKEN_ADMA;
 73
 74	sdhci = sdhci_priv(host);
 75
 76	/* clk enable */
 77	sdhci->clk = devm_clk_get(&pdev->dev, NULL);
 78	if (IS_ERR(sdhci->clk)) {
 79		ret = PTR_ERR(sdhci->clk);
 80		dev_dbg(&pdev->dev, "Error getting clock\n");
 81		goto err;
 82	}
 83
 84	ret = clk_prepare_enable(sdhci->clk);
 85	if (ret) {
 86		dev_dbg(&pdev->dev, "Error enabling clock\n");
 87		goto err;
 88	}
 89
 90	ret = clk_set_rate(sdhci->clk, 50000000);
 91	if (ret)
 92		dev_dbg(&pdev->dev, "Error setting desired clk, clk=%lu\n",
 93				clk_get_rate(sdhci->clk));
 94
 95	/*
 96	 * It is optional to use GPIOs for sdhci card detection. If we
 97	 * find a descriptor using slot GPIO, we use it.
 98	 */
 99	ret = mmc_gpiod_request_cd(host->mmc, "cd", 0, false, 0);
100	if (ret == -EPROBE_DEFER)
101		goto disable_clk;
102
103	ret = sdhci_add_host(host);
104	if (ret)
105		goto disable_clk;
106
107	platform_set_drvdata(pdev, host);
108
109	return 0;
110
111disable_clk:
112	clk_disable_unprepare(sdhci->clk);
113err:
114	dev_err(&pdev->dev, "spear-sdhci probe failed: %d\n", ret);
115	return ret;
116}
117
118static void sdhci_remove(struct platform_device *pdev)
119{
120	struct sdhci_host *host = platform_get_drvdata(pdev);
121	struct spear_sdhci *sdhci = sdhci_priv(host);
122	int dead = 0;
123	u32 scratch;
124
125	scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
126	if (scratch == (u32)-1)
127		dead = 1;
128
129	sdhci_remove_host(host, dead);
130	clk_disable_unprepare(sdhci->clk);
131}
132
133static int sdhci_suspend(struct device *dev)
134{
135	struct sdhci_host *host = dev_get_drvdata(dev);
136	struct spear_sdhci *sdhci = sdhci_priv(host);
137	int ret;
138
139	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
140		mmc_retune_needed(host->mmc);
141
142	ret = sdhci_suspend_host(host);
143	if (!ret)
144		clk_disable(sdhci->clk);
145
146	return ret;
147}
148
149static int sdhci_resume(struct device *dev)
150{
151	struct sdhci_host *host = dev_get_drvdata(dev);
152	struct spear_sdhci *sdhci = sdhci_priv(host);
153	int ret;
154
155	ret = clk_enable(sdhci->clk);
156	if (ret) {
157		dev_dbg(dev, "Resume: Error enabling clock\n");
158		return ret;
159	}
160
161	return sdhci_resume_host(host);
162}
163
164static DEFINE_SIMPLE_DEV_PM_OPS(sdhci_pm_ops, sdhci_suspend, sdhci_resume);
165
166static const struct of_device_id sdhci_spear_id_table[] = {
167	{ .compatible = "st,spear300-sdhci" },
168	{}
169};
170MODULE_DEVICE_TABLE(of, sdhci_spear_id_table);
171
172static struct platform_driver sdhci_driver = {
173	.driver = {
174		.name	= "sdhci",
175		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
176		.pm	= pm_sleep_ptr(&sdhci_pm_ops),
177		.of_match_table = sdhci_spear_id_table,
178	},
179	.probe		= sdhci_probe,
180	.remove		= sdhci_remove,
181};
182
183module_platform_driver(sdhci_driver);
184
185MODULE_DESCRIPTION("SPEAr Secure Digital Host Controller Interface driver");
186MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
187MODULE_LICENSE("GPL v2");