xref: /openbmc/linux/drivers/usb/host/ehci-st.c (revision feac8c8b)
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 	struct ehci_hcd *ehci;
156 	int err, irq, clk = 0;
157 
158 	if (usb_disabled())
159 		return -ENODEV;
160 
161 	irq = platform_get_irq(dev, 0);
162 	if (irq < 0) {
163 		dev_err(&dev->dev, "no irq provided");
164 		return irq;
165 	}
166 	res_mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
167 	if (!res_mem) {
168 		dev_err(&dev->dev, "no memory resource provided");
169 		return -ENXIO;
170 	}
171 
172 	hcd = usb_create_hcd(&ehci_platform_hc_driver, &dev->dev,
173 			     dev_name(&dev->dev));
174 	if (!hcd)
175 		return -ENOMEM;
176 
177 	platform_set_drvdata(dev, hcd);
178 	dev->dev.platform_data = pdata;
179 	priv = hcd_to_ehci_priv(hcd);
180 	ehci = hcd_to_ehci(hcd);
181 
182 	priv->phy = devm_phy_get(&dev->dev, "usb");
183 	if (IS_ERR(priv->phy)) {
184 		err = PTR_ERR(priv->phy);
185 		goto err_put_hcd;
186 	}
187 
188 	for (clk = 0; clk < USB_MAX_CLKS; clk++) {
189 		priv->clks[clk] = of_clk_get(dev->dev.of_node, clk);
190 		if (IS_ERR(priv->clks[clk])) {
191 			err = PTR_ERR(priv->clks[clk]);
192 			if (err == -EPROBE_DEFER)
193 				goto err_put_clks;
194 			priv->clks[clk] = NULL;
195 			break;
196 		}
197 	}
198 
199 	/* some SoCs don't have a dedicated 48Mhz clock, but those that
200 	   do need the rate to be explicitly set */
201 	priv->clk48 = devm_clk_get(&dev->dev, "clk48");
202 	if (IS_ERR(priv->clk48)) {
203 		dev_info(&dev->dev, "48MHz clk not found\n");
204 		priv->clk48 = NULL;
205 	}
206 
207 	priv->pwr =
208 		devm_reset_control_get_optional_shared(&dev->dev, "power");
209 	if (IS_ERR(priv->pwr)) {
210 		err = PTR_ERR(priv->pwr);
211 		if (err == -EPROBE_DEFER)
212 			goto err_put_clks;
213 		priv->pwr = NULL;
214 	}
215 
216 	priv->rst =
217 		devm_reset_control_get_optional_shared(&dev->dev, "softreset");
218 	if (IS_ERR(priv->rst)) {
219 		err = PTR_ERR(priv->rst);
220 		if (err == -EPROBE_DEFER)
221 			goto err_put_clks;
222 		priv->rst = NULL;
223 	}
224 
225 	if (pdata->power_on) {
226 		err = pdata->power_on(dev);
227 		if (err < 0)
228 			goto err_put_clks;
229 	}
230 
231 	hcd->rsrc_start = res_mem->start;
232 	hcd->rsrc_len = resource_size(res_mem);
233 
234 	hcd->regs = devm_ioremap_resource(&dev->dev, res_mem);
235 	if (IS_ERR(hcd->regs)) {
236 		err = PTR_ERR(hcd->regs);
237 		goto err_put_clks;
238 	}
239 
240 	err = usb_add_hcd(hcd, irq, IRQF_SHARED);
241 	if (err)
242 		goto err_put_clks;
243 
244 	device_wakeup_enable(hcd->self.controller);
245 	platform_set_drvdata(dev, hcd);
246 
247 	return err;
248 
249 err_put_clks:
250 	while (--clk >= 0)
251 		clk_put(priv->clks[clk]);
252 err_put_hcd:
253 	if (pdata == &ehci_platform_defaults)
254 		dev->dev.platform_data = NULL;
255 
256 	usb_put_hcd(hcd);
257 
258 	return err;
259 }
260 
261 static int st_ehci_platform_remove(struct platform_device *dev)
262 {
263 	struct usb_hcd *hcd = platform_get_drvdata(dev);
264 	struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
265 	struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
266 	int clk;
267 
268 	usb_remove_hcd(hcd);
269 
270 	if (pdata->power_off)
271 		pdata->power_off(dev);
272 
273 	for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++)
274 		clk_put(priv->clks[clk]);
275 
276 	usb_put_hcd(hcd);
277 
278 	if (pdata == &ehci_platform_defaults)
279 		dev->dev.platform_data = NULL;
280 
281 	return 0;
282 }
283 
284 #ifdef CONFIG_PM_SLEEP
285 
286 static int st_ehci_suspend(struct device *dev)
287 {
288 	struct usb_hcd *hcd = dev_get_drvdata(dev);
289 	struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
290 	struct platform_device *pdev = to_platform_device(dev);
291 	bool do_wakeup = device_may_wakeup(dev);
292 	int ret;
293 
294 	ret = ehci_suspend(hcd, do_wakeup);
295 	if (ret)
296 		return ret;
297 
298 	if (pdata->power_suspend)
299 		pdata->power_suspend(pdev);
300 
301 	pinctrl_pm_select_sleep_state(dev);
302 
303 	return ret;
304 }
305 
306 static int st_ehci_resume(struct device *dev)
307 {
308 	struct usb_hcd *hcd = dev_get_drvdata(dev);
309 	struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
310 	struct platform_device *pdev = to_platform_device(dev);
311 	int err;
312 
313 	pinctrl_pm_select_default_state(dev);
314 
315 	if (pdata->power_on) {
316 		err = pdata->power_on(pdev);
317 		if (err < 0)
318 			return err;
319 	}
320 
321 	ehci_resume(hcd, false);
322 	return 0;
323 }
324 
325 static SIMPLE_DEV_PM_OPS(st_ehci_pm_ops, st_ehci_suspend, st_ehci_resume);
326 
327 #endif /* CONFIG_PM_SLEEP */
328 
329 static const struct of_device_id st_ehci_ids[] = {
330 	{ .compatible = "st,st-ehci-300x", },
331 	{ /* sentinel */ }
332 };
333 MODULE_DEVICE_TABLE(of, st_ehci_ids);
334 
335 static struct platform_driver ehci_platform_driver = {
336 	.probe		= st_ehci_platform_probe,
337 	.remove		= st_ehci_platform_remove,
338 	.shutdown	= usb_hcd_platform_shutdown,
339 	.driver		= {
340 		.name	= "st-ehci",
341 #ifdef CONFIG_PM_SLEEP
342 		.pm	= &st_ehci_pm_ops,
343 #endif
344 		.of_match_table = st_ehci_ids,
345 	}
346 };
347 
348 static int __init ehci_platform_init(void)
349 {
350 	if (usb_disabled())
351 		return -ENODEV;
352 
353 	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
354 
355 	ehci_init_driver(&ehci_platform_hc_driver, &platform_overrides);
356 	return platform_driver_register(&ehci_platform_driver);
357 }
358 module_init(ehci_platform_init);
359 
360 static void __exit ehci_platform_cleanup(void)
361 {
362 	platform_driver_unregister(&ehci_platform_driver);
363 }
364 module_exit(ehci_platform_cleanup);
365 
366 MODULE_DESCRIPTION(DRIVER_DESC);
367 MODULE_AUTHOR("Peter Griffin <peter.griffin@linaro.org>");
368 MODULE_LICENSE("GPL");
369