xref: /openbmc/linux/drivers/mmc/host/sdhci-spear.c (revision 6aa7de05)
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/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 
33 struct spear_sdhci {
34 	struct clk *clk;
35 	int card_int_gpio;
36 };
37 
38 /* sdhci ops */
39 static 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 
46 static 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 
58 static 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 
134 disable_clk:
135 	clk_disable_unprepare(sdhci->clk);
136 err_host:
137 	sdhci_free_host(host);
138 err:
139 	dev_err(&pdev->dev, "spear-sdhci probe failed: %d\n", ret);
140 	return ret;
141 }
142 
143 static 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
162 static 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 	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
169 		mmc_retune_needed(host->mmc);
170 
171 	ret = sdhci_suspend_host(host);
172 	if (!ret)
173 		clk_disable(sdhci->clk);
174 
175 	return ret;
176 }
177 
178 static int sdhci_resume(struct device *dev)
179 {
180 	struct sdhci_host *host = dev_get_drvdata(dev);
181 	struct spear_sdhci *sdhci = sdhci_priv(host);
182 	int ret;
183 
184 	ret = clk_enable(sdhci->clk);
185 	if (ret) {
186 		dev_dbg(dev, "Resume: Error enabling clock\n");
187 		return ret;
188 	}
189 
190 	return sdhci_resume_host(host);
191 }
192 #endif
193 
194 static SIMPLE_DEV_PM_OPS(sdhci_pm_ops, sdhci_suspend, sdhci_resume);
195 
196 #ifdef CONFIG_OF
197 static const struct of_device_id sdhci_spear_id_table[] = {
198 	{ .compatible = "st,spear300-sdhci" },
199 	{}
200 };
201 MODULE_DEVICE_TABLE(of, sdhci_spear_id_table);
202 #endif
203 
204 static struct platform_driver sdhci_driver = {
205 	.driver = {
206 		.name	= "sdhci",
207 		.pm	= &sdhci_pm_ops,
208 		.of_match_table = of_match_ptr(sdhci_spear_id_table),
209 	},
210 	.probe		= sdhci_probe,
211 	.remove		= sdhci_remove,
212 };
213 
214 module_platform_driver(sdhci_driver);
215 
216 MODULE_DESCRIPTION("SPEAr Secure Digital Host Controller Interface driver");
217 MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
218 MODULE_LICENSE("GPL v2");
219