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 <viresh.linux@gmail.com>
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/gpio.h>
19#include <linux/highmem.h>
20#include <linux/module.h>
21#include <linux/interrupt.h>
22#include <linux/irq.h>
23#include <linux/of.h>
24#include <linux/of_gpio.h>
25#include <linux/platform_device.h>
26#include <linux/pm.h>
27#include <linux/slab.h>
28#include <linux/mmc/host.h>
29#include <linux/mmc/slot-gpio.h>
30#include <linux/io.h>
31#include "sdhci.h"
32
33struct spear_sdhci {
34	struct clk *clk;
35	int card_int_gpio;
36};
37
38/* sdhci ops */
39static const struct sdhci_ops sdhci_pltfm_ops = {
40	.set_clock = sdhci_set_clock,
41	.set_bus_width = sdhci_set_bus_width,
42	.reset = sdhci_reset,
43	.set_uhs_signaling = sdhci_set_uhs_signaling,
44};
45
46static void sdhci_probe_config_dt(struct device_node *np,
47				struct spear_sdhci *host)
48{
49	int cd_gpio;
50
51	cd_gpio = of_get_named_gpio(np, "cd-gpios", 0);
52	if (!gpio_is_valid(cd_gpio))
53		cd_gpio = -1;
54
55	host->card_int_gpio = cd_gpio;
56}
57
58static int sdhci_probe(struct platform_device *pdev)
59{
60	struct sdhci_host *host;
61	struct resource *iomem;
62	struct spear_sdhci *sdhci;
63	struct device *dev;
64	int ret;
65
66	dev = pdev->dev.parent ? pdev->dev.parent : &pdev->dev;
67	host = sdhci_alloc_host(dev, sizeof(*sdhci));
68	if (IS_ERR(host)) {
69		ret = PTR_ERR(host);
70		dev_dbg(&pdev->dev, "cannot allocate memory for sdhci\n");
71		goto err;
72	}
73
74	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
75	host->ioaddr = devm_ioremap_resource(&pdev->dev, iomem);
76	if (IS_ERR(host->ioaddr)) {
77		ret = PTR_ERR(host->ioaddr);
78		dev_dbg(&pdev->dev, "unable to map iomem: %d\n", ret);
79		goto err_host;
80	}
81
82	host->hw_name = "sdhci";
83	host->ops = &sdhci_pltfm_ops;
84	host->irq = platform_get_irq(pdev, 0);
85	host->quirks = SDHCI_QUIRK_BROKEN_ADMA;
86
87	sdhci = sdhci_priv(host);
88
89	/* clk enable */
90	sdhci->clk = devm_clk_get(&pdev->dev, NULL);
91	if (IS_ERR(sdhci->clk)) {
92		ret = PTR_ERR(sdhci->clk);
93		dev_dbg(&pdev->dev, "Error getting clock\n");
94		goto err_host;
95	}
96
97	ret = clk_prepare_enable(sdhci->clk);
98	if (ret) {
99		dev_dbg(&pdev->dev, "Error enabling clock\n");
100		goto err_host;
101	}
102
103	ret = clk_set_rate(sdhci->clk, 50000000);
104	if (ret)
105		dev_dbg(&pdev->dev, "Error setting desired clk, clk=%lu\n",
106				clk_get_rate(sdhci->clk));
107
108	sdhci_probe_config_dt(pdev->dev.of_node, sdhci);
109	/*
110	 * It is optional to use GPIOs for sdhci card detection. If
111	 * sdhci->card_int_gpio < 0, then use original sdhci lines otherwise
112	 * GPIO lines. We use the built-in GPIO support for this.
113	 */
114	if (sdhci->card_int_gpio >= 0) {
115		ret = mmc_gpio_request_cd(host->mmc, sdhci->card_int_gpio, 0);
116		if (ret < 0) {
117			dev_dbg(&pdev->dev,
118				"failed to request card-detect gpio%d\n",
119				sdhci->card_int_gpio);
120			goto disable_clk;
121		}
122	}
123
124	ret = sdhci_add_host(host);
125	if (ret) {
126		dev_dbg(&pdev->dev, "error adding host\n");
127		goto disable_clk;
128	}
129
130	platform_set_drvdata(pdev, host);
131
132	return 0;
133
134disable_clk:
135	clk_disable_unprepare(sdhci->clk);
136err_host:
137	sdhci_free_host(host);
138err:
139	dev_err(&pdev->dev, "spear-sdhci probe failed: %d\n", ret);
140	return ret;
141}
142
143static int sdhci_remove(struct platform_device *pdev)
144{
145	struct sdhci_host *host = platform_get_drvdata(pdev);
146	struct spear_sdhci *sdhci = sdhci_priv(host);
147	int dead = 0;
148	u32 scratch;
149
150	scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
151	if (scratch == (u32)-1)
152		dead = 1;
153
154	sdhci_remove_host(host, dead);
155	clk_disable_unprepare(sdhci->clk);
156	sdhci_free_host(host);
157
158	return 0;
159}
160
161#ifdef CONFIG_PM_SLEEP
162static int sdhci_suspend(struct device *dev)
163{
164	struct sdhci_host *host = dev_get_drvdata(dev);
165	struct spear_sdhci *sdhci = sdhci_priv(host);
166	int ret;
167
168	ret = sdhci_suspend_host(host);
169	if (!ret)
170		clk_disable(sdhci->clk);
171
172	return ret;
173}
174
175static int sdhci_resume(struct device *dev)
176{
177	struct sdhci_host *host = dev_get_drvdata(dev);
178	struct spear_sdhci *sdhci = sdhci_priv(host);
179	int ret;
180
181	ret = clk_enable(sdhci->clk);
182	if (ret) {
183		dev_dbg(dev, "Resume: Error enabling clock\n");
184		return ret;
185	}
186
187	return sdhci_resume_host(host);
188}
189#endif
190
191static SIMPLE_DEV_PM_OPS(sdhci_pm_ops, sdhci_suspend, sdhci_resume);
192
193#ifdef CONFIG_OF
194static const struct of_device_id sdhci_spear_id_table[] = {
195	{ .compatible = "st,spear300-sdhci" },
196	{}
197};
198MODULE_DEVICE_TABLE(of, sdhci_spear_id_table);
199#endif
200
201static struct platform_driver sdhci_driver = {
202	.driver = {
203		.name	= "sdhci",
204		.pm	= &sdhci_pm_ops,
205		.of_match_table = of_match_ptr(sdhci_spear_id_table),
206	},
207	.probe		= sdhci_probe,
208	.remove		= sdhci_remove,
209};
210
211module_platform_driver(sdhci_driver);
212
213MODULE_DESCRIPTION("SPEAr Secure Digital Host Controller Interface driver");
214MODULE_AUTHOR("Viresh Kumar <viresh.linux@gmail.com>");
215MODULE_LICENSE("GPL v2");
216