xref: /openbmc/linux/drivers/mmc/host/sdhci-spear.c (revision 2223cbec)
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/sdhci-spear.h>
30 #include <linux/io.h>
31 #include "sdhci.h"
32 
33 struct spear_sdhci {
34 	struct clk *clk;
35 	struct sdhci_plat_data *data;
36 };
37 
38 /* sdhci ops */
39 static struct sdhci_ops sdhci_pltfm_ops = {
40 	/* Nothing to do for now. */
41 };
42 
43 /* gpio card detection interrupt handler */
44 static irqreturn_t sdhci_gpio_irq(int irq, void *dev_id)
45 {
46 	struct platform_device *pdev = dev_id;
47 	struct sdhci_host *host = platform_get_drvdata(pdev);
48 	struct spear_sdhci *sdhci = dev_get_platdata(&pdev->dev);
49 	unsigned long gpio_irq_type;
50 	int val;
51 
52 	val = gpio_get_value(sdhci->data->card_int_gpio);
53 
54 	/* val == 1 -> card removed, val == 0 -> card inserted */
55 	/* if card removed - set irq for low level, else vice versa */
56 	gpio_irq_type = val ? IRQF_TRIGGER_LOW : IRQF_TRIGGER_HIGH;
57 	irq_set_irq_type(irq, gpio_irq_type);
58 
59 	if (sdhci->data->card_power_gpio >= 0) {
60 		if (!sdhci->data->power_always_enb) {
61 			/* if card inserted, give power, otherwise remove it */
62 			val = sdhci->data->power_active_high ? !val : val ;
63 			gpio_set_value(sdhci->data->card_power_gpio, val);
64 		}
65 	}
66 
67 	/* inform sdhci driver about card insertion/removal */
68 	tasklet_schedule(&host->card_tasklet);
69 
70 	return IRQ_HANDLED;
71 }
72 
73 #ifdef CONFIG_OF
74 static struct sdhci_plat_data * __devinit
75 sdhci_probe_config_dt(struct platform_device *pdev)
76 {
77 	struct device_node *np = pdev->dev.of_node;
78 	struct sdhci_plat_data *pdata = NULL;
79 	int cd_gpio;
80 
81 	cd_gpio = of_get_named_gpio(np, "cd-gpios", 0);
82 	if (!gpio_is_valid(cd_gpio))
83 		cd_gpio = -1;
84 
85 	/* If pdata is required */
86 	if (cd_gpio != -1) {
87 		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
88 		if (!pdata) {
89 			dev_err(&pdev->dev, "DT: kzalloc failed\n");
90 			return ERR_PTR(-ENOMEM);
91 		}
92 	}
93 
94 	pdata->card_int_gpio = cd_gpio;
95 
96 	return pdata;
97 }
98 #else
99 static struct sdhci_plat_data * __devinit
100 sdhci_probe_config_dt(struct platform_device *pdev)
101 {
102 	return ERR_PTR(-ENOSYS);
103 }
104 #endif
105 
106 static int __devinit sdhci_probe(struct platform_device *pdev)
107 {
108 	struct device_node *np = pdev->dev.of_node;
109 	struct sdhci_host *host;
110 	struct resource *iomem;
111 	struct spear_sdhci *sdhci;
112 	int ret;
113 
114 	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
115 	if (!iomem) {
116 		ret = -ENOMEM;
117 		dev_dbg(&pdev->dev, "memory resource not defined\n");
118 		goto err;
119 	}
120 
121 	if (!devm_request_mem_region(&pdev->dev, iomem->start,
122 				resource_size(iomem), "spear-sdhci")) {
123 		ret = -EBUSY;
124 		dev_dbg(&pdev->dev, "cannot request region\n");
125 		goto err;
126 	}
127 
128 	sdhci = devm_kzalloc(&pdev->dev, sizeof(*sdhci), GFP_KERNEL);
129 	if (!sdhci) {
130 		ret = -ENOMEM;
131 		dev_dbg(&pdev->dev, "cannot allocate memory for sdhci\n");
132 		goto err;
133 	}
134 
135 	/* clk enable */
136 	sdhci->clk = clk_get(&pdev->dev, NULL);
137 	if (IS_ERR(sdhci->clk)) {
138 		ret = PTR_ERR(sdhci->clk);
139 		dev_dbg(&pdev->dev, "Error getting clock\n");
140 		goto err;
141 	}
142 
143 	ret = clk_prepare_enable(sdhci->clk);
144 	if (ret) {
145 		dev_dbg(&pdev->dev, "Error enabling clock\n");
146 		goto put_clk;
147 	}
148 
149 	if (np) {
150 		sdhci->data = sdhci_probe_config_dt(pdev);
151 		if (IS_ERR(sdhci->data)) {
152 			dev_err(&pdev->dev, "DT: Failed to get pdata\n");
153 			return -ENODEV;
154 		}
155 	} else {
156 		sdhci->data = dev_get_platdata(&pdev->dev);
157 	}
158 
159 	pdev->dev.platform_data = sdhci;
160 
161 	if (pdev->dev.parent)
162 		host = sdhci_alloc_host(pdev->dev.parent, 0);
163 	else
164 		host = sdhci_alloc_host(&pdev->dev, 0);
165 
166 	if (IS_ERR(host)) {
167 		ret = PTR_ERR(host);
168 		dev_dbg(&pdev->dev, "error allocating host\n");
169 		goto disable_clk;
170 	}
171 
172 	host->hw_name = "sdhci";
173 	host->ops = &sdhci_pltfm_ops;
174 	host->irq = platform_get_irq(pdev, 0);
175 	host->quirks = SDHCI_QUIRK_BROKEN_ADMA;
176 
177 	host->ioaddr = devm_ioremap(&pdev->dev, iomem->start,
178 			resource_size(iomem));
179 	if (!host->ioaddr) {
180 		ret = -ENOMEM;
181 		dev_dbg(&pdev->dev, "failed to remap registers\n");
182 		goto free_host;
183 	}
184 
185 	ret = sdhci_add_host(host);
186 	if (ret) {
187 		dev_dbg(&pdev->dev, "error adding host\n");
188 		goto free_host;
189 	}
190 
191 	platform_set_drvdata(pdev, host);
192 
193 	/*
194 	 * It is optional to use GPIOs for sdhci Power control & sdhci card
195 	 * interrupt detection. If sdhci->data is NULL, then use original sdhci
196 	 * lines otherwise GPIO lines.
197 	 * If GPIO is selected for power control, then power should be disabled
198 	 * after card removal and should be enabled when card insertion
199 	 * interrupt occurs
200 	 */
201 	if (!sdhci->data)
202 		return 0;
203 
204 	if (sdhci->data->card_power_gpio >= 0) {
205 		int val = 0;
206 
207 		ret = devm_gpio_request(&pdev->dev,
208 				sdhci->data->card_power_gpio, "sdhci");
209 		if (ret < 0) {
210 			dev_dbg(&pdev->dev, "gpio request fail: %d\n",
211 					sdhci->data->card_power_gpio);
212 			goto set_drvdata;
213 		}
214 
215 		if (sdhci->data->power_always_enb)
216 			val = sdhci->data->power_active_high;
217 		else
218 			val = !sdhci->data->power_active_high;
219 
220 		ret = gpio_direction_output(sdhci->data->card_power_gpio, val);
221 		if (ret) {
222 			dev_dbg(&pdev->dev, "gpio set direction fail: %d\n",
223 					sdhci->data->card_power_gpio);
224 			goto set_drvdata;
225 		}
226 	}
227 
228 	if (sdhci->data->card_int_gpio >= 0) {
229 		ret = devm_gpio_request(&pdev->dev, sdhci->data->card_int_gpio,
230 				"sdhci");
231 		if (ret < 0) {
232 			dev_dbg(&pdev->dev, "gpio request fail: %d\n",
233 					sdhci->data->card_int_gpio);
234 			goto set_drvdata;
235 		}
236 
237 		ret = gpio_direction_input(sdhci->data->card_int_gpio);
238 		if (ret) {
239 			dev_dbg(&pdev->dev, "gpio set direction fail: %d\n",
240 					sdhci->data->card_int_gpio);
241 			goto set_drvdata;
242 		}
243 		ret = devm_request_irq(&pdev->dev,
244 				gpio_to_irq(sdhci->data->card_int_gpio),
245 				sdhci_gpio_irq, IRQF_TRIGGER_LOW,
246 				mmc_hostname(host->mmc), pdev);
247 		if (ret) {
248 			dev_dbg(&pdev->dev, "gpio request irq fail: %d\n",
249 					sdhci->data->card_int_gpio);
250 			goto set_drvdata;
251 		}
252 
253 	}
254 
255 	return 0;
256 
257 set_drvdata:
258 	platform_set_drvdata(pdev, NULL);
259 	sdhci_remove_host(host, 1);
260 free_host:
261 	sdhci_free_host(host);
262 disable_clk:
263 	clk_disable_unprepare(sdhci->clk);
264 put_clk:
265 	clk_put(sdhci->clk);
266 err:
267 	dev_err(&pdev->dev, "spear-sdhci probe failed: %d\n", ret);
268 	return ret;
269 }
270 
271 static int __devexit sdhci_remove(struct platform_device *pdev)
272 {
273 	struct sdhci_host *host = platform_get_drvdata(pdev);
274 	struct spear_sdhci *sdhci = dev_get_platdata(&pdev->dev);
275 	int dead = 0;
276 	u32 scratch;
277 
278 	platform_set_drvdata(pdev, NULL);
279 	scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
280 	if (scratch == (u32)-1)
281 		dead = 1;
282 
283 	sdhci_remove_host(host, dead);
284 	sdhci_free_host(host);
285 	clk_disable_unprepare(sdhci->clk);
286 	clk_put(sdhci->clk);
287 
288 	return 0;
289 }
290 
291 #ifdef CONFIG_PM
292 static int sdhci_suspend(struct device *dev)
293 {
294 	struct sdhci_host *host = dev_get_drvdata(dev);
295 	struct spear_sdhci *sdhci = dev_get_platdata(dev);
296 	int ret;
297 
298 	ret = sdhci_suspend_host(host);
299 	if (!ret)
300 		clk_disable_unprepare(sdhci->clk);
301 
302 	return ret;
303 }
304 
305 static int sdhci_resume(struct device *dev)
306 {
307 	struct sdhci_host *host = dev_get_drvdata(dev);
308 	struct spear_sdhci *sdhci = dev_get_platdata(dev);
309 	int ret;
310 
311 	ret = clk_prepare_enable(sdhci->clk);
312 	if (ret) {
313 		dev_dbg(dev, "Resume: Error enabling clock\n");
314 		return ret;
315 	}
316 
317 	return sdhci_resume_host(host);
318 }
319 #endif
320 
321 static SIMPLE_DEV_PM_OPS(sdhci_pm_ops, sdhci_suspend, sdhci_resume);
322 
323 #ifdef CONFIG_OF
324 static const struct of_device_id sdhci_spear_id_table[] = {
325 	{ .compatible = "st,spear300-sdhci" },
326 	{}
327 };
328 MODULE_DEVICE_TABLE(of, sdhci_spear_id_table);
329 #endif
330 
331 static struct platform_driver sdhci_driver = {
332 	.driver = {
333 		.name	= "sdhci",
334 		.owner	= THIS_MODULE,
335 		.pm	= &sdhci_pm_ops,
336 		.of_match_table = of_match_ptr(sdhci_spear_id_table),
337 	},
338 	.probe		= sdhci_probe,
339 	.remove		= __devexit_p(sdhci_remove),
340 };
341 
342 module_platform_driver(sdhci_driver);
343 
344 MODULE_DESCRIPTION("SPEAr Secure Digital Host Controller Interface driver");
345 MODULE_AUTHOR("Viresh Kumar <viresh.linux@gmail.com>");
346 MODULE_LICENSE("GPL v2");
347