1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * NOP USB transceiver for all USB transceiver which are either built-in
4 * into USB IP or which are mostly autonomous.
5 *
6 * Copyright (C) 2009 Texas Instruments Inc
7 * Author: Ajay Kumar Gupta <ajay.gupta@ti.com>
8 *
9 * Current status:
10 *	This provides a "nop" transceiver for PHYs which are
11 *	autonomous such as isp1504, isp1707, etc.
12 */
13
14#include <linux/module.h>
15#include <linux/platform_device.h>
16#include <linux/dma-mapping.h>
17#include <linux/usb/gadget.h>
18#include <linux/usb/otg.h>
19#include <linux/usb/usb_phy_generic.h>
20#include <linux/slab.h>
21#include <linux/clk.h>
22#include <linux/regulator/consumer.h>
23#include <linux/of.h>
24#include <linux/gpio/consumer.h>
25#include <linux/delay.h>
26
27#include "phy-generic.h"
28
29#define VBUS_IRQ_FLAGS \
30	(IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | \
31		IRQF_ONESHOT)
32
33struct platform_device *usb_phy_generic_register(void)
34{
35	return platform_device_register_simple("usb_phy_generic",
36			PLATFORM_DEVID_AUTO, NULL, 0);
37}
38EXPORT_SYMBOL_GPL(usb_phy_generic_register);
39
40void usb_phy_generic_unregister(struct platform_device *pdev)
41{
42	platform_device_unregister(pdev);
43}
44EXPORT_SYMBOL_GPL(usb_phy_generic_unregister);
45
46static int nop_set_suspend(struct usb_phy *x, int suspend)
47{
48	struct usb_phy_generic *nop = dev_get_drvdata(x->dev);
49	int ret = 0;
50
51	if (suspend) {
52		if (!IS_ERR(nop->clk))
53			clk_disable_unprepare(nop->clk);
54		if (!IS_ERR(nop->vcc) && !device_may_wakeup(x->dev))
55			ret = regulator_disable(nop->vcc);
56	} else {
57		if (!IS_ERR(nop->vcc) && !device_may_wakeup(x->dev))
58			ret = regulator_enable(nop->vcc);
59		if (!IS_ERR(nop->clk))
60			clk_prepare_enable(nop->clk);
61	}
62
63	return ret;
64}
65
66static void nop_reset(struct usb_phy_generic *nop)
67{
68	if (!nop->gpiod_reset)
69		return;
70
71	gpiod_set_value_cansleep(nop->gpiod_reset, 1);
72	usleep_range(10000, 20000);
73	gpiod_set_value_cansleep(nop->gpiod_reset, 0);
74	usleep_range(10000, 30000);
75}
76
77/* interface to regulator framework */
78static int nop_set_vbus(struct usb_otg *otg, bool enable)
79{
80	int ret = 0;
81	struct usb_phy_generic *nop = dev_get_drvdata(otg->usb_phy->dev);
82
83	if (!nop->vbus_draw)
84		return 0;
85
86	if (enable && !nop->vbus_draw_enabled) {
87		ret = regulator_enable(nop->vbus_draw);
88		if (ret)
89			nop->vbus_draw_enabled = false;
90		else
91			nop->vbus_draw_enabled = true;
92
93	} else if (!enable && nop->vbus_draw_enabled) {
94		ret = regulator_disable(nop->vbus_draw);
95		nop->vbus_draw_enabled = false;
96	}
97	return ret;
98}
99
100
101static irqreturn_t nop_gpio_vbus_thread(int irq, void *data)
102{
103	struct usb_phy_generic *nop = data;
104	struct usb_otg *otg = nop->phy.otg;
105	int vbus, status;
106
107	vbus = gpiod_get_value(nop->gpiod_vbus);
108	if ((vbus ^ nop->vbus) == 0)
109		return IRQ_HANDLED;
110	nop->vbus = vbus;
111
112	if (vbus) {
113		status = USB_EVENT_VBUS;
114		otg->state = OTG_STATE_B_PERIPHERAL;
115		nop->phy.last_event = status;
116
117		atomic_notifier_call_chain(&nop->phy.notifier, status,
118					   otg->gadget);
119	} else {
120		status = USB_EVENT_NONE;
121		otg->state = OTG_STATE_B_IDLE;
122		nop->phy.last_event = status;
123
124		atomic_notifier_call_chain(&nop->phy.notifier, status,
125					   otg->gadget);
126	}
127	return IRQ_HANDLED;
128}
129
130int usb_gen_phy_init(struct usb_phy *phy)
131{
132	struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
133	int ret;
134
135	if (!IS_ERR(nop->vcc)) {
136		if (regulator_enable(nop->vcc))
137			dev_err(phy->dev, "Failed to enable power\n");
138	}
139
140	if (!IS_ERR(nop->clk)) {
141		ret = clk_prepare_enable(nop->clk);
142		if (ret)
143			return ret;
144	}
145
146	nop_reset(nop);
147
148	return 0;
149}
150EXPORT_SYMBOL_GPL(usb_gen_phy_init);
151
152void usb_gen_phy_shutdown(struct usb_phy *phy)
153{
154	struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
155
156	gpiod_set_value_cansleep(nop->gpiod_reset, 1);
157
158	if (!IS_ERR(nop->clk))
159		clk_disable_unprepare(nop->clk);
160
161	if (!IS_ERR(nop->vcc)) {
162		if (regulator_disable(nop->vcc))
163			dev_err(phy->dev, "Failed to disable power\n");
164	}
165}
166EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
167
168static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
169{
170	if (!otg)
171		return -ENODEV;
172
173	if (!gadget) {
174		otg->gadget = NULL;
175		return -ENODEV;
176	}
177
178	otg->gadget = gadget;
179	if (otg->state == OTG_STATE_B_PERIPHERAL)
180		atomic_notifier_call_chain(&otg->usb_phy->notifier,
181					   USB_EVENT_VBUS, otg->gadget);
182	else
183		otg->state = OTG_STATE_B_IDLE;
184	return 0;
185}
186
187static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
188{
189	if (!otg)
190		return -ENODEV;
191
192	if (!host) {
193		otg->host = NULL;
194		return -ENODEV;
195	}
196
197	otg->host = host;
198	return 0;
199}
200
201int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop)
202{
203	enum usb_phy_type type = USB_PHY_TYPE_USB2;
204	int err = 0;
205
206	u32 clk_rate = 0;
207	bool needs_clk = false;
208
209	if (dev->of_node) {
210		struct device_node *node = dev->of_node;
211
212		if (of_property_read_u32(node, "clock-frequency", &clk_rate))
213			clk_rate = 0;
214
215		needs_clk = of_property_read_bool(node, "clocks");
216	}
217	nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset",
218						   GPIOD_ASIS);
219	err = PTR_ERR_OR_ZERO(nop->gpiod_reset);
220	if (!err) {
221		nop->gpiod_vbus = devm_gpiod_get_optional(dev,
222						 "vbus-detect",
223						 GPIOD_ASIS);
224		err = PTR_ERR_OR_ZERO(nop->gpiod_vbus);
225	}
226
227	if (err)
228		return dev_err_probe(dev, err,
229				     "Error requesting RESET or VBUS GPIO\n");
230	if (nop->gpiod_reset)
231		gpiod_direction_output(nop->gpiod_reset, 1);
232
233	nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
234			GFP_KERNEL);
235	if (!nop->phy.otg)
236		return -ENOMEM;
237
238	nop->clk = devm_clk_get(dev, "main_clk");
239	if (IS_ERR(nop->clk)) {
240		dev_dbg(dev, "Can't get phy clock: %ld\n",
241					PTR_ERR(nop->clk));
242		if (needs_clk)
243			return PTR_ERR(nop->clk);
244	}
245
246	if (!IS_ERR(nop->clk) && clk_rate) {
247		err = clk_set_rate(nop->clk, clk_rate);
248		if (err) {
249			dev_err(dev, "Error setting clock rate\n");
250			return err;
251		}
252	}
253
254	nop->vcc = devm_regulator_get_optional(dev, "vcc");
255	if (IS_ERR(nop->vcc) && PTR_ERR(nop->vcc) != -ENODEV)
256		return dev_err_probe(dev, PTR_ERR(nop->vcc),
257				     "could not get vcc regulator\n");
258
259	nop->vbus_draw = devm_regulator_get_exclusive(dev, "vbus");
260	if (PTR_ERR(nop->vbus_draw) == -ENODEV)
261		nop->vbus_draw = NULL;
262	if (IS_ERR(nop->vbus_draw))
263		return dev_err_probe(dev, PTR_ERR(nop->vbus_draw),
264				     "could not get vbus regulator\n");
265
266	nop->dev		= dev;
267	nop->phy.dev		= nop->dev;
268	nop->phy.label		= "nop-xceiv";
269	nop->phy.set_suspend	= nop_set_suspend;
270	nop->phy.type		= type;
271
272	nop->phy.otg->state		= OTG_STATE_UNDEFINED;
273	nop->phy.otg->usb_phy		= &nop->phy;
274	nop->phy.otg->set_host		= nop_set_host;
275	nop->phy.otg->set_peripheral	= nop_set_peripheral;
276	nop->phy.otg->set_vbus          = nop_set_vbus;
277
278	return 0;
279}
280EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
281
282static int usb_phy_generic_probe(struct platform_device *pdev)
283{
284	struct device *dev = &pdev->dev;
285	struct device_node *dn = dev->of_node;
286	struct usb_phy_generic	*nop;
287	int err;
288
289	nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
290	if (!nop)
291		return -ENOMEM;
292
293	err = usb_phy_gen_create_phy(dev, nop);
294	if (err)
295		return err;
296	if (nop->gpiod_vbus) {
297		err = devm_request_threaded_irq(&pdev->dev,
298						gpiod_to_irq(nop->gpiod_vbus),
299						NULL, nop_gpio_vbus_thread,
300						VBUS_IRQ_FLAGS, "vbus_detect",
301						nop);
302		if (err) {
303			dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
304				gpiod_to_irq(nop->gpiod_vbus), err);
305			return err;
306		}
307		nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ?
308			OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE;
309	}
310
311	nop->phy.init		= usb_gen_phy_init;
312	nop->phy.shutdown	= usb_gen_phy_shutdown;
313
314	err = usb_add_phy_dev(&nop->phy);
315	if (err) {
316		dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
317			err);
318		return err;
319	}
320
321	platform_set_drvdata(pdev, nop);
322
323	device_set_wakeup_capable(&pdev->dev,
324				  of_property_read_bool(dn, "wakeup-source"));
325
326	return 0;
327}
328
329static void usb_phy_generic_remove(struct platform_device *pdev)
330{
331	struct usb_phy_generic *nop = platform_get_drvdata(pdev);
332
333	usb_remove_phy(&nop->phy);
334
335	if (nop->vbus_draw && nop->vbus_draw_enabled)
336		regulator_disable(nop->vbus_draw);
337}
338
339static const struct of_device_id nop_xceiv_dt_ids[] = {
340	{ .compatible = "usb-nop-xceiv" },
341	{ }
342};
343
344MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
345
346static struct platform_driver usb_phy_generic_driver = {
347	.probe		= usb_phy_generic_probe,
348	.remove_new	= usb_phy_generic_remove,
349	.driver		= {
350		.name	= "usb_phy_generic",
351		.of_match_table = nop_xceiv_dt_ids,
352	},
353};
354
355static int __init usb_phy_generic_init(void)
356{
357	return platform_driver_register(&usb_phy_generic_driver);
358}
359subsys_initcall(usb_phy_generic_init);
360
361static void __exit usb_phy_generic_exit(void)
362{
363	platform_driver_unregister(&usb_phy_generic_driver);
364}
365module_exit(usb_phy_generic_exit);
366
367MODULE_ALIAS("platform:usb_phy_generic");
368MODULE_AUTHOR("Texas Instruments Inc");
369MODULE_DESCRIPTION("NOP USB Transceiver driver");
370MODULE_LICENSE("GPL");
371