xref: /openbmc/linux/drivers/usb/host/ehci-st.c (revision 99a15348)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ST EHCI driver
4  *
5  * Copyright (C) 2014 STMicroelectronics – All Rights Reserved
6  *
7  * Author: Peter Griffin <peter.griffin@linaro.org>
8  *
9  * Derived from ehci-platform.c
10  */
11 
12 #include <linux/clk.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/err.h>
15 #include <linux/kernel.h>
16 #include <linux/hrtimer.h>
17 #include <linux/io.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/phy/phy.h>
21 #include <linux/platform_device.h>
22 #include <linux/reset.h>
23 #include <linux/usb.h>
24 #include <linux/usb/hcd.h>
25 #include <linux/usb/ehci_pdriver.h>
26 #include <linux/pinctrl/consumer.h>
27 
28 #include "ehci.h"
29 
30 #define USB_MAX_CLKS 3
31 
32 struct st_ehci_platform_priv {
33 	struct clk *clks[USB_MAX_CLKS];
34 	struct clk *clk48;
35 	struct reset_control *rst;
36 	struct reset_control *pwr;
37 	struct phy *phy;
38 };
39 
40 #define DRIVER_DESC "EHCI STMicroelectronics driver"
41 
42 #define hcd_to_ehci_priv(h) \
43 	((struct st_ehci_platform_priv *)hcd_to_ehci(h)->priv)
44 
45 static const char hcd_name[] = "ehci-st";
46 
47 #define EHCI_CAPS_SIZE 0x10
48 #define AHB2STBUS_INSREG01 (EHCI_CAPS_SIZE + 0x84)
49 
50 static int st_ehci_platform_reset(struct usb_hcd *hcd)
51 {
52 	struct platform_device *pdev = to_platform_device(hcd->self.controller);
53 	struct usb_ehci_pdata *pdata = dev_get_platdata(&pdev->dev);
54 	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
55 	u32 threshold;
56 
57 	/* Set EHCI packet buffer IN/OUT threshold to 128 bytes */
58 	threshold = 128 | (128 << 16);
59 	writel(threshold, hcd->regs + AHB2STBUS_INSREG01);
60 
61 	ehci->caps = hcd->regs + pdata->caps_offset;
62 	return ehci_setup(hcd);
63 }
64 
65 static int st_ehci_platform_power_on(struct platform_device *dev)
66 {
67 	struct usb_hcd *hcd = platform_get_drvdata(dev);
68 	struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
69 	int clk, ret;
70 
71 	ret = reset_control_deassert(priv->pwr);
72 	if (ret)
73 		return ret;
74 
75 	ret = reset_control_deassert(priv->rst);
76 	if (ret)
77 		goto err_assert_power;
78 
79 	/* some SoCs don't have a dedicated 48Mhz clock, but those that do
80 	   need the rate to be explicitly set */
81 	if (priv->clk48) {
82 		ret = clk_set_rate(priv->clk48, 48000000);
83 		if (ret)
84 			goto err_assert_reset;
85 	}
86 
87 	for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++) {
88 		ret = clk_prepare_enable(priv->clks[clk]);
89 		if (ret)
90 			goto err_disable_clks;
91 	}
92 
93 	ret = phy_init(priv->phy);
94 	if (ret)
95 		goto err_disable_clks;
96 
97 	ret = phy_power_on(priv->phy);
98 	if (ret)
99 		goto err_exit_phy;
100 
101 	return 0;
102 
103 err_exit_phy:
104 	phy_exit(priv->phy);
105 err_disable_clks:
106 	while (--clk >= 0)
107 		clk_disable_unprepare(priv->clks[clk]);
108 err_assert_reset:
109 	reset_control_assert(priv->rst);
110 err_assert_power:
111 	reset_control_assert(priv->pwr);
112 
113 	return ret;
114 }
115 
116 static void st_ehci_platform_power_off(struct platform_device *dev)
117 {
118 	struct usb_hcd *hcd = platform_get_drvdata(dev);
119 	struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
120 	int clk;
121 
122 	reset_control_assert(priv->pwr);
123 
124 	reset_control_assert(priv->rst);
125 
126 	phy_power_off(priv->phy);
127 
128 	phy_exit(priv->phy);
129 
130 	for (clk = USB_MAX_CLKS - 1; clk >= 0; clk--)
131 		if (priv->clks[clk])
132 			clk_disable_unprepare(priv->clks[clk]);
133 
134 }
135 
136 static struct hc_driver __read_mostly ehci_platform_hc_driver;
137 
138 static const struct ehci_driver_overrides platform_overrides __initconst = {
139 	.reset =		st_ehci_platform_reset,
140 	.extra_priv_size =	sizeof(struct st_ehci_platform_priv),
141 };
142 
143 static struct usb_ehci_pdata ehci_platform_defaults = {
144 	.power_on =		st_ehci_platform_power_on,
145 	.power_suspend =	st_ehci_platform_power_off,
146 	.power_off =		st_ehci_platform_power_off,
147 };
148 
149 static int st_ehci_platform_probe(struct platform_device *dev)
150 {
151 	struct usb_hcd *hcd;
152 	struct resource *res_mem;
153 	struct usb_ehci_pdata *pdata = &ehci_platform_defaults;
154 	struct st_ehci_platform_priv *priv;
155 	int err, irq, clk = 0;
156 
157 	if (usb_disabled())
158 		return -ENODEV;
159 
160 	irq = platform_get_irq(dev, 0);
161 	if (irq < 0)
162 		return irq;
163 	res_mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
164 	if (!res_mem) {
165 		dev_err(&dev->dev, "no memory resource provided");
166 		return -ENXIO;
167 	}
168 
169 	hcd = usb_create_hcd(&ehci_platform_hc_driver, &dev->dev,
170 			     dev_name(&dev->dev));
171 	if (!hcd)
172 		return -ENOMEM;
173 
174 	platform_set_drvdata(dev, hcd);
175 	dev->dev.platform_data = pdata;
176 	priv = hcd_to_ehci_priv(hcd);
177 
178 	priv->phy = devm_phy_get(&dev->dev, "usb");
179 	if (IS_ERR(priv->phy)) {
180 		err = PTR_ERR(priv->phy);
181 		goto err_put_hcd;
182 	}
183 
184 	for (clk = 0; clk < USB_MAX_CLKS; clk++) {
185 		priv->clks[clk] = of_clk_get(dev->dev.of_node, clk);
186 		if (IS_ERR(priv->clks[clk])) {
187 			err = PTR_ERR(priv->clks[clk]);
188 			if (err == -EPROBE_DEFER)
189 				goto err_put_clks;
190 			priv->clks[clk] = NULL;
191 			break;
192 		}
193 	}
194 
195 	/* some SoCs don't have a dedicated 48Mhz clock, but those that
196 	   do need the rate to be explicitly set */
197 	priv->clk48 = devm_clk_get(&dev->dev, "clk48");
198 	if (IS_ERR(priv->clk48)) {
199 		dev_info(&dev->dev, "48MHz clk not found\n");
200 		priv->clk48 = NULL;
201 	}
202 
203 	priv->pwr =
204 		devm_reset_control_get_optional_shared(&dev->dev, "power");
205 	if (IS_ERR(priv->pwr)) {
206 		err = PTR_ERR(priv->pwr);
207 		if (err == -EPROBE_DEFER)
208 			goto err_put_clks;
209 		priv->pwr = NULL;
210 	}
211 
212 	priv->rst =
213 		devm_reset_control_get_optional_shared(&dev->dev, "softreset");
214 	if (IS_ERR(priv->rst)) {
215 		err = PTR_ERR(priv->rst);
216 		if (err == -EPROBE_DEFER)
217 			goto err_put_clks;
218 		priv->rst = NULL;
219 	}
220 
221 	if (pdata->power_on) {
222 		err = pdata->power_on(dev);
223 		if (err < 0)
224 			goto err_put_clks;
225 	}
226 
227 	hcd->rsrc_start = res_mem->start;
228 	hcd->rsrc_len = resource_size(res_mem);
229 
230 	hcd->regs = devm_ioremap_resource(&dev->dev, res_mem);
231 	if (IS_ERR(hcd->regs)) {
232 		err = PTR_ERR(hcd->regs);
233 		goto err_put_clks;
234 	}
235 
236 	err = usb_add_hcd(hcd, irq, IRQF_SHARED);
237 	if (err)
238 		goto err_put_clks;
239 
240 	device_wakeup_enable(hcd->self.controller);
241 	platform_set_drvdata(dev, hcd);
242 
243 	return err;
244 
245 err_put_clks:
246 	while (--clk >= 0)
247 		clk_put(priv->clks[clk]);
248 err_put_hcd:
249 	if (pdata == &ehci_platform_defaults)
250 		dev->dev.platform_data = NULL;
251 
252 	usb_put_hcd(hcd);
253 
254 	return err;
255 }
256 
257 static int st_ehci_platform_remove(struct platform_device *dev)
258 {
259 	struct usb_hcd *hcd = platform_get_drvdata(dev);
260 	struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
261 	struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
262 	int clk;
263 
264 	usb_remove_hcd(hcd);
265 
266 	if (pdata->power_off)
267 		pdata->power_off(dev);
268 
269 	for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++)
270 		clk_put(priv->clks[clk]);
271 
272 	usb_put_hcd(hcd);
273 
274 	if (pdata == &ehci_platform_defaults)
275 		dev->dev.platform_data = NULL;
276 
277 	return 0;
278 }
279 
280 #ifdef CONFIG_PM_SLEEP
281 
282 static int st_ehci_suspend(struct device *dev)
283 {
284 	struct usb_hcd *hcd = dev_get_drvdata(dev);
285 	struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
286 	struct platform_device *pdev = to_platform_device(dev);
287 	bool do_wakeup = device_may_wakeup(dev);
288 	int ret;
289 
290 	ret = ehci_suspend(hcd, do_wakeup);
291 	if (ret)
292 		return ret;
293 
294 	if (pdata->power_suspend)
295 		pdata->power_suspend(pdev);
296 
297 	pinctrl_pm_select_sleep_state(dev);
298 
299 	return ret;
300 }
301 
302 static int st_ehci_resume(struct device *dev)
303 {
304 	struct usb_hcd *hcd = dev_get_drvdata(dev);
305 	struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
306 	struct platform_device *pdev = to_platform_device(dev);
307 	int err;
308 
309 	pinctrl_pm_select_default_state(dev);
310 
311 	if (pdata->power_on) {
312 		err = pdata->power_on(pdev);
313 		if (err < 0)
314 			return err;
315 	}
316 
317 	ehci_resume(hcd, false);
318 	return 0;
319 }
320 
321 static SIMPLE_DEV_PM_OPS(st_ehci_pm_ops, st_ehci_suspend, st_ehci_resume);
322 
323 #endif /* CONFIG_PM_SLEEP */
324 
325 static const struct of_device_id st_ehci_ids[] = {
326 	{ .compatible = "st,st-ehci-300x", },
327 	{ /* sentinel */ }
328 };
329 MODULE_DEVICE_TABLE(of, st_ehci_ids);
330 
331 static struct platform_driver ehci_platform_driver = {
332 	.probe		= st_ehci_platform_probe,
333 	.remove		= st_ehci_platform_remove,
334 	.shutdown	= usb_hcd_platform_shutdown,
335 	.driver		= {
336 		.name	= "st-ehci",
337 #ifdef CONFIG_PM_SLEEP
338 		.pm	= &st_ehci_pm_ops,
339 #endif
340 		.of_match_table = st_ehci_ids,
341 	}
342 };
343 
344 static int __init ehci_platform_init(void)
345 {
346 	if (usb_disabled())
347 		return -ENODEV;
348 
349 	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
350 
351 	ehci_init_driver(&ehci_platform_hc_driver, &platform_overrides);
352 	return platform_driver_register(&ehci_platform_driver);
353 }
354 module_init(ehci_platform_init);
355 
356 static void __exit ehci_platform_cleanup(void)
357 {
358 	platform_driver_unregister(&ehci_platform_driver);
359 }
360 module_exit(ehci_platform_cleanup);
361 
362 MODULE_DESCRIPTION(DRIVER_DESC);
363 MODULE_AUTHOR("Peter Griffin <peter.griffin@linaro.org>");
364 MODULE_LICENSE("GPL");
365