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  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
 45static const char hcd_name[] = "ehci-st";
 46
 47#define EHCI_CAPS_SIZE 0x10
 48#define AHB2STBUS_INSREG01 (EHCI_CAPS_SIZE + 0x84)
 49
 50static 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
 65static 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
103err_exit_phy:
104	phy_exit(priv->phy);
105err_disable_clks:
106	while (--clk >= 0)
107		clk_disable_unprepare(priv->clks[clk]);
108err_assert_reset:
109	reset_control_assert(priv->rst);
110err_assert_power:
111	reset_control_assert(priv->pwr);
112
113	return ret;
114}
115
116static 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
136static struct hc_driver __read_mostly ehci_platform_hc_driver;
137
138static 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
143static 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
149static 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
249err_put_clks:
250	while (--clk >= 0)
251		clk_put(priv->clks[clk]);
252err_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
261static 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
286static 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
306static 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
325static SIMPLE_DEV_PM_OPS(st_ehci_pm_ops, st_ehci_suspend, st_ehci_resume);
326
327#endif /* CONFIG_PM_SLEEP */
328
329static const struct of_device_id st_ehci_ids[] = {
330	{ .compatible = "st,st-ehci-300x", },
331	{ /* sentinel */ }
332};
333MODULE_DEVICE_TABLE(of, st_ehci_ids);
334
335static 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
348static 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}
358module_init(ehci_platform_init);
359
360static void __exit ehci_platform_cleanup(void)
361{
362	platform_driver_unregister(&ehci_platform_driver);
363}
364module_exit(ehci_platform_cleanup);
365
366MODULE_DESCRIPTION(DRIVER_DESC);
367MODULE_AUTHOR("Peter Griffin <peter.griffin@linaro.org>");
368MODULE_LICENSE("GPL");