xref: /openbmc/linux/drivers/usb/host/ehci-st.c (revision 23396172)
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 #define EHCI_CAPS_SIZE 0x10
46 #define AHB2STBUS_INSREG01 (EHCI_CAPS_SIZE + 0x84)
47 
st_ehci_platform_reset(struct usb_hcd * hcd)48 static int st_ehci_platform_reset(struct usb_hcd *hcd)
49 {
50 	struct platform_device *pdev = to_platform_device(hcd->self.controller);
51 	struct usb_ehci_pdata *pdata = dev_get_platdata(&pdev->dev);
52 	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
53 	u32 threshold;
54 
55 	/* Set EHCI packet buffer IN/OUT threshold to 128 bytes */
56 	threshold = 128 | (128 << 16);
57 	writel(threshold, hcd->regs + AHB2STBUS_INSREG01);
58 
59 	ehci->caps = hcd->regs + pdata->caps_offset;
60 	return ehci_setup(hcd);
61 }
62 
st_ehci_platform_power_on(struct platform_device * dev)63 static int st_ehci_platform_power_on(struct platform_device *dev)
64 {
65 	struct usb_hcd *hcd = platform_get_drvdata(dev);
66 	struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
67 	int clk, ret;
68 
69 	ret = reset_control_deassert(priv->pwr);
70 	if (ret)
71 		return ret;
72 
73 	ret = reset_control_deassert(priv->rst);
74 	if (ret)
75 		goto err_assert_power;
76 
77 	/* some SoCs don't have a dedicated 48Mhz clock, but those that do
78 	   need the rate to be explicitly set */
79 	if (priv->clk48) {
80 		ret = clk_set_rate(priv->clk48, 48000000);
81 		if (ret)
82 			goto err_assert_reset;
83 	}
84 
85 	for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++) {
86 		ret = clk_prepare_enable(priv->clks[clk]);
87 		if (ret)
88 			goto err_disable_clks;
89 	}
90 
91 	ret = phy_init(priv->phy);
92 	if (ret)
93 		goto err_disable_clks;
94 
95 	ret = phy_power_on(priv->phy);
96 	if (ret)
97 		goto err_exit_phy;
98 
99 	return 0;
100 
101 err_exit_phy:
102 	phy_exit(priv->phy);
103 err_disable_clks:
104 	while (--clk >= 0)
105 		clk_disable_unprepare(priv->clks[clk]);
106 err_assert_reset:
107 	reset_control_assert(priv->rst);
108 err_assert_power:
109 	reset_control_assert(priv->pwr);
110 
111 	return ret;
112 }
113 
st_ehci_platform_power_off(struct platform_device * dev)114 static void st_ehci_platform_power_off(struct platform_device *dev)
115 {
116 	struct usb_hcd *hcd = platform_get_drvdata(dev);
117 	struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
118 	int clk;
119 
120 	reset_control_assert(priv->pwr);
121 
122 	reset_control_assert(priv->rst);
123 
124 	phy_power_off(priv->phy);
125 
126 	phy_exit(priv->phy);
127 
128 	for (clk = USB_MAX_CLKS - 1; clk >= 0; clk--)
129 		if (priv->clks[clk])
130 			clk_disable_unprepare(priv->clks[clk]);
131 
132 }
133 
134 static struct hc_driver __read_mostly ehci_platform_hc_driver;
135 
136 static const struct ehci_driver_overrides platform_overrides __initconst = {
137 	.reset =		st_ehci_platform_reset,
138 	.extra_priv_size =	sizeof(struct st_ehci_platform_priv),
139 };
140 
141 static struct usb_ehci_pdata ehci_platform_defaults = {
142 	.power_on =		st_ehci_platform_power_on,
143 	.power_suspend =	st_ehci_platform_power_off,
144 	.power_off =		st_ehci_platform_power_off,
145 };
146 
st_ehci_platform_probe(struct platform_device * dev)147 static int st_ehci_platform_probe(struct platform_device *dev)
148 {
149 	struct usb_hcd *hcd;
150 	struct resource *res_mem;
151 	struct usb_ehci_pdata *pdata = &ehci_platform_defaults;
152 	struct st_ehci_platform_priv *priv;
153 	int err, irq, clk = 0;
154 
155 	if (usb_disabled())
156 		return -ENODEV;
157 
158 	irq = platform_get_irq(dev, 0);
159 	if (irq < 0)
160 		return irq;
161 
162 	hcd = usb_create_hcd(&ehci_platform_hc_driver, &dev->dev,
163 			     dev_name(&dev->dev));
164 	if (!hcd)
165 		return -ENOMEM;
166 
167 	platform_set_drvdata(dev, hcd);
168 	dev->dev.platform_data = pdata;
169 	priv = hcd_to_ehci_priv(hcd);
170 
171 	priv->phy = devm_phy_get(&dev->dev, "usb");
172 	if (IS_ERR(priv->phy)) {
173 		err = PTR_ERR(priv->phy);
174 		goto err_put_hcd;
175 	}
176 
177 	for (clk = 0; clk < USB_MAX_CLKS; clk++) {
178 		priv->clks[clk] = of_clk_get(dev->dev.of_node, clk);
179 		if (IS_ERR(priv->clks[clk])) {
180 			err = PTR_ERR(priv->clks[clk]);
181 			if (err == -EPROBE_DEFER)
182 				goto err_put_clks;
183 			priv->clks[clk] = NULL;
184 			break;
185 		}
186 	}
187 
188 	/* some SoCs don't have a dedicated 48Mhz clock, but those that
189 	   do need the rate to be explicitly set */
190 	priv->clk48 = devm_clk_get(&dev->dev, "clk48");
191 	if (IS_ERR(priv->clk48)) {
192 		dev_info(&dev->dev, "48MHz clk not found\n");
193 		priv->clk48 = NULL;
194 	}
195 
196 	priv->pwr =
197 		devm_reset_control_get_optional_shared(&dev->dev, "power");
198 	if (IS_ERR(priv->pwr)) {
199 		err = PTR_ERR(priv->pwr);
200 		if (err == -EPROBE_DEFER)
201 			goto err_put_clks;
202 		priv->pwr = NULL;
203 	}
204 
205 	priv->rst =
206 		devm_reset_control_get_optional_shared(&dev->dev, "softreset");
207 	if (IS_ERR(priv->rst)) {
208 		err = PTR_ERR(priv->rst);
209 		if (err == -EPROBE_DEFER)
210 			goto err_put_clks;
211 		priv->rst = NULL;
212 	}
213 
214 	if (pdata->power_on) {
215 		err = pdata->power_on(dev);
216 		if (err < 0)
217 			goto err_put_clks;
218 	}
219 
220 	hcd->regs = devm_platform_get_and_ioremap_resource(dev, 0, &res_mem);
221 	if (IS_ERR(hcd->regs)) {
222 		err = PTR_ERR(hcd->regs);
223 		goto err_put_clks;
224 	}
225 	hcd->rsrc_start = res_mem->start;
226 	hcd->rsrc_len = resource_size(res_mem);
227 
228 	err = usb_add_hcd(hcd, irq, IRQF_SHARED);
229 	if (err)
230 		goto err_put_clks;
231 
232 	device_wakeup_enable(hcd->self.controller);
233 	platform_set_drvdata(dev, hcd);
234 
235 	return err;
236 
237 err_put_clks:
238 	while (--clk >= 0)
239 		clk_put(priv->clks[clk]);
240 err_put_hcd:
241 	if (pdata == &ehci_platform_defaults)
242 		dev->dev.platform_data = NULL;
243 
244 	usb_put_hcd(hcd);
245 
246 	return err;
247 }
248 
st_ehci_platform_remove(struct platform_device * dev)249 static void st_ehci_platform_remove(struct platform_device *dev)
250 {
251 	struct usb_hcd *hcd = platform_get_drvdata(dev);
252 	struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
253 	struct st_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
254 	int clk;
255 
256 	usb_remove_hcd(hcd);
257 
258 	if (pdata->power_off)
259 		pdata->power_off(dev);
260 
261 	for (clk = 0; clk < USB_MAX_CLKS && priv->clks[clk]; clk++)
262 		clk_put(priv->clks[clk]);
263 
264 	usb_put_hcd(hcd);
265 
266 	if (pdata == &ehci_platform_defaults)
267 		dev->dev.platform_data = NULL;
268 }
269 
270 #ifdef CONFIG_PM_SLEEP
271 
st_ehci_suspend(struct device * dev)272 static int st_ehci_suspend(struct device *dev)
273 {
274 	struct usb_hcd *hcd = dev_get_drvdata(dev);
275 	struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
276 	struct platform_device *pdev = to_platform_device(dev);
277 	bool do_wakeup = device_may_wakeup(dev);
278 	int ret;
279 
280 	ret = ehci_suspend(hcd, do_wakeup);
281 	if (ret)
282 		return ret;
283 
284 	if (pdata->power_suspend)
285 		pdata->power_suspend(pdev);
286 
287 	pinctrl_pm_select_sleep_state(dev);
288 
289 	return ret;
290 }
291 
st_ehci_resume(struct device * dev)292 static int st_ehci_resume(struct device *dev)
293 {
294 	struct usb_hcd *hcd = dev_get_drvdata(dev);
295 	struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
296 	struct platform_device *pdev = to_platform_device(dev);
297 	int err;
298 
299 	pinctrl_pm_select_default_state(dev);
300 
301 	if (pdata->power_on) {
302 		err = pdata->power_on(pdev);
303 		if (err < 0)
304 			return err;
305 	}
306 
307 	ehci_resume(hcd, false);
308 	return 0;
309 }
310 
311 static SIMPLE_DEV_PM_OPS(st_ehci_pm_ops, st_ehci_suspend, st_ehci_resume);
312 
313 #endif /* CONFIG_PM_SLEEP */
314 
315 static const struct of_device_id st_ehci_ids[] = {
316 	{ .compatible = "st,st-ehci-300x", },
317 	{ /* sentinel */ }
318 };
319 MODULE_DEVICE_TABLE(of, st_ehci_ids);
320 
321 static struct platform_driver ehci_platform_driver = {
322 	.probe		= st_ehci_platform_probe,
323 	.remove_new	= st_ehci_platform_remove,
324 	.shutdown	= usb_hcd_platform_shutdown,
325 	.driver		= {
326 		.name	= "st-ehci",
327 #ifdef CONFIG_PM_SLEEP
328 		.pm	= &st_ehci_pm_ops,
329 #endif
330 		.of_match_table = st_ehci_ids,
331 	}
332 };
333 
ehci_platform_init(void)334 static int __init ehci_platform_init(void)
335 {
336 	if (usb_disabled())
337 		return -ENODEV;
338 
339 	ehci_init_driver(&ehci_platform_hc_driver, &platform_overrides);
340 	return platform_driver_register(&ehci_platform_driver);
341 }
342 module_init(ehci_platform_init);
343 
ehci_platform_cleanup(void)344 static void __exit ehci_platform_cleanup(void)
345 {
346 	platform_driver_unregister(&ehci_platform_driver);
347 }
348 module_exit(ehci_platform_cleanup);
349 
350 MODULE_DESCRIPTION(DRIVER_DESC);
351 MODULE_AUTHOR("Peter Griffin <peter.griffin@linaro.org>");
352 MODULE_LICENSE("GPL");
353