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
32struct 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
48static 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
63static 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
101err_exit_phy:
102	phy_exit(priv->phy);
103err_disable_clks:
104	while (--clk >= 0)
105		clk_disable_unprepare(priv->clks[clk]);
106err_assert_reset:
107	reset_control_assert(priv->rst);
108err_assert_power:
109	reset_control_assert(priv->pwr);
110
111	return ret;
112}
113
114static 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
134static struct hc_driver __read_mostly ehci_platform_hc_driver;
135
136static 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
141static 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
147static 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
237err_put_clks:
238	while (--clk >= 0)
239		clk_put(priv->clks[clk]);
240err_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
249static 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
272static 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
292static 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
311static SIMPLE_DEV_PM_OPS(st_ehci_pm_ops, st_ehci_suspend, st_ehci_resume);
312
313#endif /* CONFIG_PM_SLEEP */
314
315static const struct of_device_id st_ehci_ids[] = {
316	{ .compatible = "st,st-ehci-300x", },
317	{ /* sentinel */ }
318};
319MODULE_DEVICE_TABLE(of, st_ehci_ids);
320
321static 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
334static 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}
342module_init(ehci_platform_init);
343
344static void __exit ehci_platform_cleanup(void)
345{
346	platform_driver_unregister(&ehci_platform_driver);
347}
348module_exit(ehci_platform_cleanup);
349
350MODULE_DESCRIPTION(DRIVER_DESC);
351MODULE_AUTHOR("Peter Griffin <peter.griffin@linaro.org>");
352MODULE_LICENSE("GPL");
353