xref: /openbmc/linux/drivers/usb/host/ehci-st.c (revision 4f6cce39)
1 /*
2  * ST EHCI driver
3  *
4  * Copyright (C) 2014 STMicroelectronics – All Rights Reserved
5  *
6  * Author: Peter Griffin <peter.griffin@linaro.org>
7  *
8  * Derived from ehci-platform.c
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  */
14 
15 #include <linux/clk.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/err.h>
18 #include <linux/kernel.h>
19 #include <linux/hrtimer.h>
20 #include <linux/io.h>
21 #include <linux/module.h>
22 #include <linux/of.h>
23 #include <linux/phy/phy.h>
24 #include <linux/platform_device.h>
25 #include <linux/reset.h>
26 #include <linux/usb.h>
27 #include <linux/usb/hcd.h>
28 #include <linux/usb/ehci_pdriver.h>
29 
30 #include "ehci.h"
31 
32 #define USB_MAX_CLKS 3
33 
34 struct st_ehci_platform_priv {
35 	struct clk *clks[USB_MAX_CLKS];
36 	struct clk *clk48;
37 	struct reset_control *rst;
38 	struct reset_control *pwr;
39 	struct phy *phy;
40 };
41 
42 #define DRIVER_DESC "EHCI STMicroelectronics driver"
43 
44 #define hcd_to_ehci_priv(h) \
45 	((struct st_ehci_platform_priv *)hcd_to_ehci(h)->priv)
46 
47 static const char hcd_name[] = "ehci-st";
48 
49 #define EHCI_CAPS_SIZE 0x10
50 #define AHB2STBUS_INSREG01 (EHCI_CAPS_SIZE + 0x84)
51 
52 static int st_ehci_platform_reset(struct usb_hcd *hcd)
53 {
54 	struct platform_device *pdev = to_platform_device(hcd->self.controller);
55 	struct usb_ehci_pdata *pdata = dev_get_platdata(&pdev->dev);
56 	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
57 	u32 threshold;
58 
59 	/* Set EHCI packet buffer IN/OUT threshold to 128 bytes */
60 	threshold = 128 | (128 << 16);
61 	writel(threshold, hcd->regs + AHB2STBUS_INSREG01);
62 
63 	ehci->caps = hcd->regs + pdata->caps_offset;
64 	return ehci_setup(hcd);
65 }
66 
67 static int st_ehci_platform_power_on(struct platform_device *dev)
68 {
69 	struct usb_hcd *hcd = platform_get_drvdata(dev);
70 	struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
71 	int clk, ret;
72 
73 	ret = reset_control_deassert(priv->pwr);
74 	if (ret)
75 		return ret;
76 
77 	ret = reset_control_deassert(priv->rst);
78 	if (ret)
79 		goto err_assert_power;
80 
81 	/* some SoCs don't have a dedicated 48Mhz clock, but those that do
82 	   need the rate to be explicitly set */
83 	if (priv->clk48) {
84 		ret = clk_set_rate(priv->clk48, 48000000);
85 		if (ret)
86 			goto err_assert_reset;
87 	}
88 
89 	for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++) {
90 		ret = clk_prepare_enable(priv->clks[clk]);
91 		if (ret)
92 			goto err_disable_clks;
93 	}
94 
95 	ret = phy_init(priv->phy);
96 	if (ret)
97 		goto err_disable_clks;
98 
99 	ret = phy_power_on(priv->phy);
100 	if (ret)
101 		goto err_exit_phy;
102 
103 	return 0;
104 
105 err_exit_phy:
106 	phy_exit(priv->phy);
107 err_disable_clks:
108 	while (--clk >= 0)
109 		clk_disable_unprepare(priv->clks[clk]);
110 err_assert_reset:
111 	reset_control_assert(priv->rst);
112 err_assert_power:
113 	reset_control_assert(priv->pwr);
114 
115 	return ret;
116 }
117 
118 static void st_ehci_platform_power_off(struct platform_device *dev)
119 {
120 	struct usb_hcd *hcd = platform_get_drvdata(dev);
121 	struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
122 	int clk;
123 
124 	reset_control_assert(priv->pwr);
125 
126 	reset_control_assert(priv->rst);
127 
128 	phy_power_off(priv->phy);
129 
130 	phy_exit(priv->phy);
131 
132 	for (clk = USB_MAX_CLKS - 1; clk >= 0; clk--)
133 		if (priv->clks[clk])
134 			clk_disable_unprepare(priv->clks[clk]);
135 
136 }
137 
138 static struct hc_driver __read_mostly ehci_platform_hc_driver;
139 
140 static const struct ehci_driver_overrides platform_overrides __initconst = {
141 	.reset =		st_ehci_platform_reset,
142 	.extra_priv_size =	sizeof(struct st_ehci_platform_priv),
143 };
144 
145 static struct usb_ehci_pdata ehci_platform_defaults = {
146 	.power_on =		st_ehci_platform_power_on,
147 	.power_suspend =	st_ehci_platform_power_off,
148 	.power_off =		st_ehci_platform_power_off,
149 };
150 
151 static int st_ehci_platform_probe(struct platform_device *dev)
152 {
153 	struct usb_hcd *hcd;
154 	struct resource *res_mem;
155 	struct usb_ehci_pdata *pdata = &ehci_platform_defaults;
156 	struct st_ehci_platform_priv *priv;
157 	struct ehci_hcd *ehci;
158 	int err, irq, clk = 0;
159 
160 	if (usb_disabled())
161 		return -ENODEV;
162 
163 	irq = platform_get_irq(dev, 0);
164 	if (irq < 0) {
165 		dev_err(&dev->dev, "no irq provided");
166 		return irq;
167 	}
168 	res_mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
169 	if (!res_mem) {
170 		dev_err(&dev->dev, "no memory resource provided");
171 		return -ENXIO;
172 	}
173 
174 	hcd = usb_create_hcd(&ehci_platform_hc_driver, &dev->dev,
175 			     dev_name(&dev->dev));
176 	if (!hcd)
177 		return -ENOMEM;
178 
179 	platform_set_drvdata(dev, hcd);
180 	dev->dev.platform_data = pdata;
181 	priv = hcd_to_ehci_priv(hcd);
182 	ehci = hcd_to_ehci(hcd);
183 
184 	priv->phy = devm_phy_get(&dev->dev, "usb");
185 	if (IS_ERR(priv->phy)) {
186 		err = PTR_ERR(priv->phy);
187 		goto err_put_hcd;
188 	}
189 
190 	for (clk = 0; clk < USB_MAX_CLKS; clk++) {
191 		priv->clks[clk] = of_clk_get(dev->dev.of_node, clk);
192 		if (IS_ERR(priv->clks[clk])) {
193 			err = PTR_ERR(priv->clks[clk]);
194 			if (err == -EPROBE_DEFER)
195 				goto err_put_clks;
196 			priv->clks[clk] = NULL;
197 			break;
198 		}
199 	}
200 
201 	/* some SoCs don't have a dedicated 48Mhz clock, but those that
202 	   do need the rate to be explicitly set */
203 	priv->clk48 = devm_clk_get(&dev->dev, "clk48");
204 	if (IS_ERR(priv->clk48)) {
205 		dev_info(&dev->dev, "48MHz clk not found\n");
206 		priv->clk48 = NULL;
207 	}
208 
209 	priv->pwr =
210 		devm_reset_control_get_optional_shared(&dev->dev, "power");
211 	if (IS_ERR(priv->pwr)) {
212 		err = PTR_ERR(priv->pwr);
213 		if (err == -EPROBE_DEFER)
214 			goto err_put_clks;
215 		priv->pwr = NULL;
216 	}
217 
218 	priv->rst =
219 		devm_reset_control_get_optional_shared(&dev->dev, "softreset");
220 	if (IS_ERR(priv->rst)) {
221 		err = PTR_ERR(priv->rst);
222 		if (err == -EPROBE_DEFER)
223 			goto err_put_clks;
224 		priv->rst = NULL;
225 	}
226 
227 	if (pdata->power_on) {
228 		err = pdata->power_on(dev);
229 		if (err < 0)
230 			goto err_put_clks;
231 	}
232 
233 	hcd->rsrc_start = res_mem->start;
234 	hcd->rsrc_len = resource_size(res_mem);
235 
236 	hcd->regs = devm_ioremap_resource(&dev->dev, res_mem);
237 	if (IS_ERR(hcd->regs)) {
238 		err = PTR_ERR(hcd->regs);
239 		goto err_put_clks;
240 	}
241 
242 	err = usb_add_hcd(hcd, irq, IRQF_SHARED);
243 	if (err)
244 		goto err_put_clks;
245 
246 	device_wakeup_enable(hcd->self.controller);
247 	platform_set_drvdata(dev, hcd);
248 
249 	return err;
250 
251 err_put_clks:
252 	while (--clk >= 0)
253 		clk_put(priv->clks[clk]);
254 err_put_hcd:
255 	if (pdata == &ehci_platform_defaults)
256 		dev->dev.platform_data = NULL;
257 
258 	usb_put_hcd(hcd);
259 
260 	return err;
261 }
262 
263 static int st_ehci_platform_remove(struct platform_device *dev)
264 {
265 	struct usb_hcd *hcd = platform_get_drvdata(dev);
266 	struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
267 	struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
268 	int clk;
269 
270 	usb_remove_hcd(hcd);
271 
272 	if (pdata->power_off)
273 		pdata->power_off(dev);
274 
275 	for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++)
276 		clk_put(priv->clks[clk]);
277 
278 	usb_put_hcd(hcd);
279 
280 	if (pdata == &ehci_platform_defaults)
281 		dev->dev.platform_data = NULL;
282 
283 	return 0;
284 }
285 
286 #ifdef CONFIG_PM_SLEEP
287 
288 static int st_ehci_suspend(struct device *dev)
289 {
290 	struct usb_hcd *hcd = dev_get_drvdata(dev);
291 	struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
292 	struct platform_device *pdev = to_platform_device(dev);
293 	bool do_wakeup = device_may_wakeup(dev);
294 	int ret;
295 
296 	ret = ehci_suspend(hcd, do_wakeup);
297 	if (ret)
298 		return ret;
299 
300 	if (pdata->power_suspend)
301 		pdata->power_suspend(pdev);
302 
303 	pinctrl_pm_select_sleep_state(dev);
304 
305 	return ret;
306 }
307 
308 static int st_ehci_resume(struct device *dev)
309 {
310 	struct usb_hcd *hcd = dev_get_drvdata(dev);
311 	struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
312 	struct platform_device *pdev = to_platform_device(dev);
313 	int err;
314 
315 	pinctrl_pm_select_default_state(dev);
316 
317 	if (pdata->power_on) {
318 		err = pdata->power_on(pdev);
319 		if (err < 0)
320 			return err;
321 	}
322 
323 	ehci_resume(hcd, false);
324 	return 0;
325 }
326 
327 static SIMPLE_DEV_PM_OPS(st_ehci_pm_ops, st_ehci_suspend, st_ehci_resume);
328 
329 #endif /* CONFIG_PM_SLEEP */
330 
331 static const struct of_device_id st_ehci_ids[] = {
332 	{ .compatible = "st,st-ehci-300x", },
333 	{ /* sentinel */ }
334 };
335 MODULE_DEVICE_TABLE(of, st_ehci_ids);
336 
337 static struct platform_driver ehci_platform_driver = {
338 	.probe		= st_ehci_platform_probe,
339 	.remove		= st_ehci_platform_remove,
340 	.shutdown	= usb_hcd_platform_shutdown,
341 	.driver		= {
342 		.name	= "st-ehci",
343 #ifdef CONFIG_PM_SLEEP
344 		.pm	= &st_ehci_pm_ops,
345 #endif
346 		.of_match_table = st_ehci_ids,
347 	}
348 };
349 
350 static int __init ehci_platform_init(void)
351 {
352 	if (usb_disabled())
353 		return -ENODEV;
354 
355 	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
356 
357 	ehci_init_driver(&ehci_platform_hc_driver, &platform_overrides);
358 	return platform_driver_register(&ehci_platform_driver);
359 }
360 module_init(ehci_platform_init);
361 
362 static void __exit ehci_platform_cleanup(void)
363 {
364 	platform_driver_unregister(&ehci_platform_driver);
365 }
366 module_exit(ehci_platform_cleanup);
367 
368 MODULE_DESCRIPTION(DRIVER_DESC);
369 MODULE_AUTHOR("Peter Griffin <peter.griffin@linaro.org>");
370 MODULE_LICENSE("GPL");
371