xref: /openbmc/linux/drivers/mmc/host/sdhci-spear.c (revision 113a87f8)
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 const 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 *sdhci_probe_config_dt(struct platform_device *pdev)
75 {
76 	struct device_node *np = pdev->dev.of_node;
77 	struct sdhci_plat_data *pdata = NULL;
78 	int cd_gpio;
79 
80 	cd_gpio = of_get_named_gpio(np, "cd-gpios", 0);
81 	if (!gpio_is_valid(cd_gpio))
82 		cd_gpio = -1;
83 
84 	/* If pdata is required */
85 	if (cd_gpio != -1) {
86 		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
87 		if (!pdata) {
88 			dev_err(&pdev->dev, "DT: kzalloc failed\n");
89 			return ERR_PTR(-ENOMEM);
90 		}
91 	}
92 
93 	pdata->card_int_gpio = cd_gpio;
94 
95 	return pdata;
96 }
97 #else
98 static struct sdhci_plat_data *sdhci_probe_config_dt(struct platform_device *pdev)
99 {
100 	return ERR_PTR(-ENOSYS);
101 }
102 #endif
103 
104 static int sdhci_probe(struct platform_device *pdev)
105 {
106 	struct device_node *np = pdev->dev.of_node;
107 	struct sdhci_host *host;
108 	struct resource *iomem;
109 	struct spear_sdhci *sdhci;
110 	int ret;
111 
112 	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
113 	if (!iomem) {
114 		ret = -ENOMEM;
115 		dev_dbg(&pdev->dev, "memory resource not defined\n");
116 		goto err;
117 	}
118 
119 	if (!devm_request_mem_region(&pdev->dev, iomem->start,
120 				resource_size(iomem), "spear-sdhci")) {
121 		ret = -EBUSY;
122 		dev_dbg(&pdev->dev, "cannot request region\n");
123 		goto err;
124 	}
125 
126 	sdhci = devm_kzalloc(&pdev->dev, sizeof(*sdhci), GFP_KERNEL);
127 	if (!sdhci) {
128 		ret = -ENOMEM;
129 		dev_dbg(&pdev->dev, "cannot allocate memory for sdhci\n");
130 		goto err;
131 	}
132 
133 	/* clk enable */
134 	sdhci->clk = clk_get(&pdev->dev, NULL);
135 	if (IS_ERR(sdhci->clk)) {
136 		ret = PTR_ERR(sdhci->clk);
137 		dev_dbg(&pdev->dev, "Error getting clock\n");
138 		goto err;
139 	}
140 
141 	ret = clk_prepare_enable(sdhci->clk);
142 	if (ret) {
143 		dev_dbg(&pdev->dev, "Error enabling clock\n");
144 		goto put_clk;
145 	}
146 
147 	ret = clk_set_rate(sdhci->clk, 50000000);
148 	if (ret)
149 		dev_dbg(&pdev->dev, "Error setting desired clk, clk=%lu\n",
150 				clk_get_rate(sdhci->clk));
151 
152 	if (np) {
153 		sdhci->data = sdhci_probe_config_dt(pdev);
154 		if (IS_ERR(sdhci->data)) {
155 			dev_err(&pdev->dev, "DT: Failed to get pdata\n");
156 			return -ENODEV;
157 		}
158 	} else {
159 		sdhci->data = dev_get_platdata(&pdev->dev);
160 	}
161 
162 	pdev->dev.platform_data = sdhci;
163 
164 	if (pdev->dev.parent)
165 		host = sdhci_alloc_host(pdev->dev.parent, 0);
166 	else
167 		host = sdhci_alloc_host(&pdev->dev, 0);
168 
169 	if (IS_ERR(host)) {
170 		ret = PTR_ERR(host);
171 		dev_dbg(&pdev->dev, "error allocating host\n");
172 		goto disable_clk;
173 	}
174 
175 	host->hw_name = "sdhci";
176 	host->ops = &sdhci_pltfm_ops;
177 	host->irq = platform_get_irq(pdev, 0);
178 	host->quirks = SDHCI_QUIRK_BROKEN_ADMA;
179 
180 	host->ioaddr = devm_ioremap(&pdev->dev, iomem->start,
181 			resource_size(iomem));
182 	if (!host->ioaddr) {
183 		ret = -ENOMEM;
184 		dev_dbg(&pdev->dev, "failed to remap registers\n");
185 		goto free_host;
186 	}
187 
188 	ret = sdhci_add_host(host);
189 	if (ret) {
190 		dev_dbg(&pdev->dev, "error adding host\n");
191 		goto free_host;
192 	}
193 
194 	platform_set_drvdata(pdev, host);
195 
196 	/*
197 	 * It is optional to use GPIOs for sdhci Power control & sdhci card
198 	 * interrupt detection. If sdhci->data is NULL, then use original sdhci
199 	 * lines otherwise GPIO lines.
200 	 * If GPIO is selected for power control, then power should be disabled
201 	 * after card removal and should be enabled when card insertion
202 	 * interrupt occurs
203 	 */
204 	if (!sdhci->data)
205 		return 0;
206 
207 	if (sdhci->data->card_power_gpio >= 0) {
208 		int val = 0;
209 
210 		ret = devm_gpio_request(&pdev->dev,
211 				sdhci->data->card_power_gpio, "sdhci");
212 		if (ret < 0) {
213 			dev_dbg(&pdev->dev, "gpio request fail: %d\n",
214 					sdhci->data->card_power_gpio);
215 			goto set_drvdata;
216 		}
217 
218 		if (sdhci->data->power_always_enb)
219 			val = sdhci->data->power_active_high;
220 		else
221 			val = !sdhci->data->power_active_high;
222 
223 		ret = gpio_direction_output(sdhci->data->card_power_gpio, val);
224 		if (ret) {
225 			dev_dbg(&pdev->dev, "gpio set direction fail: %d\n",
226 					sdhci->data->card_power_gpio);
227 			goto set_drvdata;
228 		}
229 	}
230 
231 	if (sdhci->data->card_int_gpio >= 0) {
232 		ret = devm_gpio_request(&pdev->dev, sdhci->data->card_int_gpio,
233 				"sdhci");
234 		if (ret < 0) {
235 			dev_dbg(&pdev->dev, "gpio request fail: %d\n",
236 					sdhci->data->card_int_gpio);
237 			goto set_drvdata;
238 		}
239 
240 		ret = gpio_direction_input(sdhci->data->card_int_gpio);
241 		if (ret) {
242 			dev_dbg(&pdev->dev, "gpio set direction fail: %d\n",
243 					sdhci->data->card_int_gpio);
244 			goto set_drvdata;
245 		}
246 		ret = devm_request_irq(&pdev->dev,
247 				gpio_to_irq(sdhci->data->card_int_gpio),
248 				sdhci_gpio_irq, IRQF_TRIGGER_LOW,
249 				mmc_hostname(host->mmc), pdev);
250 		if (ret) {
251 			dev_dbg(&pdev->dev, "gpio request irq fail: %d\n",
252 					sdhci->data->card_int_gpio);
253 			goto set_drvdata;
254 		}
255 
256 	}
257 
258 	return 0;
259 
260 set_drvdata:
261 	sdhci_remove_host(host, 1);
262 free_host:
263 	sdhci_free_host(host);
264 disable_clk:
265 	clk_disable_unprepare(sdhci->clk);
266 put_clk:
267 	clk_put(sdhci->clk);
268 err:
269 	dev_err(&pdev->dev, "spear-sdhci probe failed: %d\n", ret);
270 	return ret;
271 }
272 
273 static int sdhci_remove(struct platform_device *pdev)
274 {
275 	struct sdhci_host *host = platform_get_drvdata(pdev);
276 	struct spear_sdhci *sdhci = dev_get_platdata(&pdev->dev);
277 	int dead = 0;
278 	u32 scratch;
279 
280 	scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
281 	if (scratch == (u32)-1)
282 		dead = 1;
283 
284 	sdhci_remove_host(host, dead);
285 	sdhci_free_host(host);
286 	clk_disable_unprepare(sdhci->clk);
287 	clk_put(sdhci->clk);
288 
289 	return 0;
290 }
291 
292 #ifdef CONFIG_PM_SLEEP
293 static int sdhci_suspend(struct device *dev)
294 {
295 	struct sdhci_host *host = dev_get_drvdata(dev);
296 	struct spear_sdhci *sdhci = dev_get_platdata(dev);
297 	int ret;
298 
299 	ret = sdhci_suspend_host(host);
300 	if (!ret)
301 		clk_disable(sdhci->clk);
302 
303 	return ret;
304 }
305 
306 static int sdhci_resume(struct device *dev)
307 {
308 	struct sdhci_host *host = dev_get_drvdata(dev);
309 	struct spear_sdhci *sdhci = dev_get_platdata(dev);
310 	int ret;
311 
312 	ret = clk_enable(sdhci->clk);
313 	if (ret) {
314 		dev_dbg(dev, "Resume: Error enabling clock\n");
315 		return ret;
316 	}
317 
318 	return sdhci_resume_host(host);
319 }
320 #endif
321 
322 static SIMPLE_DEV_PM_OPS(sdhci_pm_ops, sdhci_suspend, sdhci_resume);
323 
324 #ifdef CONFIG_OF
325 static const struct of_device_id sdhci_spear_id_table[] = {
326 	{ .compatible = "st,spear300-sdhci" },
327 	{}
328 };
329 MODULE_DEVICE_TABLE(of, sdhci_spear_id_table);
330 #endif
331 
332 static struct platform_driver sdhci_driver = {
333 	.driver = {
334 		.name	= "sdhci",
335 		.owner	= THIS_MODULE,
336 		.pm	= &sdhci_pm_ops,
337 		.of_match_table = of_match_ptr(sdhci_spear_id_table),
338 	},
339 	.probe		= sdhci_probe,
340 	.remove		= sdhci_remove,
341 };
342 
343 module_platform_driver(sdhci_driver);
344 
345 MODULE_DESCRIPTION("SPEAr Secure Digital Host Controller Interface driver");
346 MODULE_AUTHOR("Viresh Kumar <viresh.linux@gmail.com>");
347 MODULE_LICENSE("GPL v2");
348