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_host;
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 = -EINVAL;
70		goto err_host;
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_host;
82	}
83
84	ret = clk_prepare_enable(sdhci->clk);
85	if (ret) {
86		dev_dbg(&pdev->dev, "Error enabling clock\n");
87		goto err_host;
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_host:
114	sdhci_free_host(host);
115err:
116	dev_err(&pdev->dev, "spear-sdhci probe failed: %d\n", ret);
117	return ret;
118}
119
120static int sdhci_remove(struct platform_device *pdev)
121{
122	struct sdhci_host *host = platform_get_drvdata(pdev);
123	struct spear_sdhci *sdhci = sdhci_priv(host);
124	int dead = 0;
125	u32 scratch;
126
127	scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
128	if (scratch == (u32)-1)
129		dead = 1;
130
131	sdhci_remove_host(host, dead);
132	clk_disable_unprepare(sdhci->clk);
133	sdhci_free_host(host);
134
135	return 0;
136}
137
138#ifdef CONFIG_PM_SLEEP
139static int sdhci_suspend(struct device *dev)
140{
141	struct sdhci_host *host = dev_get_drvdata(dev);
142	struct spear_sdhci *sdhci = sdhci_priv(host);
143	int ret;
144
145	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
146		mmc_retune_needed(host->mmc);
147
148	ret = sdhci_suspend_host(host);
149	if (!ret)
150		clk_disable(sdhci->clk);
151
152	return ret;
153}
154
155static int sdhci_resume(struct device *dev)
156{
157	struct sdhci_host *host = dev_get_drvdata(dev);
158	struct spear_sdhci *sdhci = sdhci_priv(host);
159	int ret;
160
161	ret = clk_enable(sdhci->clk);
162	if (ret) {
163		dev_dbg(dev, "Resume: Error enabling clock\n");
164		return ret;
165	}
166
167	return sdhci_resume_host(host);
168}
169#endif
170
171static SIMPLE_DEV_PM_OPS(sdhci_pm_ops, sdhci_suspend, sdhci_resume);
172
173#ifdef CONFIG_OF
174static const struct of_device_id sdhci_spear_id_table[] = {
175	{ .compatible = "st,spear300-sdhci" },
176	{}
177};
178MODULE_DEVICE_TABLE(of, sdhci_spear_id_table);
179#endif
180
181static struct platform_driver sdhci_driver = {
182	.driver = {
183		.name	= "sdhci",
184		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
185		.pm	= &sdhci_pm_ops,
186		.of_match_table = of_match_ptr(sdhci_spear_id_table),
187	},
188	.probe		= sdhci_probe,
189	.remove		= sdhci_remove,
190};
191
192module_platform_driver(sdhci_driver);
193
194MODULE_DESCRIPTION("SPEAr Secure Digital Host Controller Interface driver");
195MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
196MODULE_LICENSE("GPL v2");
197