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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 <[email protected]>
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/property.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 clk_disable_unprepare(nop->clk);
53 if (!IS_ERR(nop->vcc) && !device_may_wakeup(x->dev))
54 ret = regulator_disable(nop->vcc);
55 } else {
56 if (!IS_ERR(nop->vcc) && !device_may_wakeup(x->dev))
57 ret = regulator_enable(nop->vcc);
58 clk_prepare_enable(nop->clk);
59 }
60
61 return ret;
62}
63
64static void nop_reset(struct usb_phy_generic *nop)
65{
66 if (!nop->gpiod_reset)
67 return;
68
69 gpiod_set_value_cansleep(nop->gpiod_reset, 1);
70 usleep_range(10000, 20000);
71 gpiod_set_value_cansleep(nop->gpiod_reset, 0);
72 usleep_range(10000, 30000);
73}
74
75/* interface to regulator framework */
76static int nop_set_vbus(struct usb_otg *otg, bool enable)
77{
78 int ret = 0;
79 struct usb_phy_generic *nop = dev_get_drvdata(otg->usb_phy->dev);
80
81 if (!nop->vbus_draw)
82 return 0;
83
84 if (enable && !nop->vbus_draw_enabled) {
85 ret = regulator_enable(nop->vbus_draw);
86 if (ret)
87 nop->vbus_draw_enabled = false;
88 else
89 nop->vbus_draw_enabled = true;
90
91 } else if (!enable && nop->vbus_draw_enabled) {
92 ret = regulator_disable(nop->vbus_draw);
93 nop->vbus_draw_enabled = false;
94 }
95 return ret;
96}
97
98
99static irqreturn_t nop_gpio_vbus_thread(int irq, void *data)
100{
101 struct usb_phy_generic *nop = data;
102 struct usb_otg *otg = nop->phy.otg;
103 int vbus, status;
104
105 vbus = gpiod_get_value(nop->gpiod_vbus);
106 if ((vbus ^ nop->vbus) == 0)
107 return IRQ_HANDLED;
108 nop->vbus = vbus;
109
110 if (vbus) {
111 status = USB_EVENT_VBUS;
112 otg->state = OTG_STATE_B_PERIPHERAL;
113 nop->phy.last_event = status;
114
115 atomic_notifier_call_chain(&nop->phy.notifier, status,
116 otg->gadget);
117 } else {
118 status = USB_EVENT_NONE;
119 otg->state = OTG_STATE_B_IDLE;
120 nop->phy.last_event = status;
121
122 atomic_notifier_call_chain(&nop->phy.notifier, status,
123 otg->gadget);
124 }
125 return IRQ_HANDLED;
126}
127
128int usb_gen_phy_init(struct usb_phy *phy)
129{
130 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
131 int ret;
132
133 if (!IS_ERR(nop->vcc)) {
134 if (regulator_enable(nop->vcc))
135 dev_err(phy->dev, "Failed to enable power\n");
136 }
137
138 ret = clk_prepare_enable(nop->clk);
139 if (ret)
140 return ret;
141
142 nop_reset(nop);
143
144 return 0;
145}
146EXPORT_SYMBOL_GPL(usb_gen_phy_init);
147
148void usb_gen_phy_shutdown(struct usb_phy *phy)
149{
150 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
151
152 gpiod_set_value_cansleep(nop->gpiod_reset, 1);
153
154 clk_disable_unprepare(nop->clk);
155
156 if (!IS_ERR(nop->vcc)) {
157 if (regulator_disable(nop->vcc))
158 dev_err(phy->dev, "Failed to disable power\n");
159 }
160}
161EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
162
163static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
164{
165 if (!otg)
166 return -ENODEV;
167
168 if (!gadget) {
169 otg->gadget = NULL;
170 return -ENODEV;
171 }
172
173 otg->gadget = gadget;
174 if (otg->state == OTG_STATE_B_PERIPHERAL)
175 atomic_notifier_call_chain(&otg->usb_phy->notifier,
176 USB_EVENT_VBUS, otg->gadget);
177 else
178 otg->state = OTG_STATE_B_IDLE;
179 return 0;
180}
181
182static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
183{
184 if (!otg)
185 return -ENODEV;
186
187 if (!host) {
188 otg->host = NULL;
189 return -ENODEV;
190 }
191
192 otg->host = host;
193 return 0;
194}
195
196int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop)
197{
198 enum usb_phy_type type = USB_PHY_TYPE_USB2;
199 int err = 0;
200 u32 clk_rate = 0;
201
202 device_property_read_u32(dev, "clock-frequency", &clk_rate);
203 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset",
204 GPIOD_ASIS);
205 err = PTR_ERR_OR_ZERO(nop->gpiod_reset);
206 if (!err) {
207 nop->gpiod_vbus = devm_gpiod_get_optional(dev,
208 "vbus-detect",
209 GPIOD_ASIS);
210 err = PTR_ERR_OR_ZERO(nop->gpiod_vbus);
211 }
212
213 if (err)
214 return dev_err_probe(dev, err,
215 "Error requesting RESET or VBUS GPIO\n");
216 if (nop->gpiod_reset)
217 gpiod_direction_output(nop->gpiod_reset, 1);
218
219 nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
220 GFP_KERNEL);
221 if (!nop->phy.otg)
222 return -ENOMEM;
223
224 nop->clk = devm_clk_get_optional(dev, "main_clk");
225 if (IS_ERR(nop->clk))
226 return dev_err_probe(dev, PTR_ERR(nop->clk),
227 "Can't get phy clock\n");
228
229 if (clk_rate) {
230 err = clk_set_rate(nop->clk, clk_rate);
231 if (err)
232 return dev_err_probe(dev, err,
233 "Error setting clock rate\n");
234 }
235
236 nop->vcc = devm_regulator_get_optional(dev, "vcc");
237 if (IS_ERR(nop->vcc) && PTR_ERR(nop->vcc) != -ENODEV)
238 return dev_err_probe(dev, PTR_ERR(nop->vcc),
239 "could not get vcc regulator\n");
240
241 nop->vbus_draw = devm_regulator_get_exclusive(dev, "vbus");
242 if (PTR_ERR(nop->vbus_draw) == -ENODEV)
243 nop->vbus_draw = NULL;
244 if (IS_ERR(nop->vbus_draw))
245 return dev_err_probe(dev, PTR_ERR(nop->vbus_draw),
246 "could not get vbus regulator\n");
247
248 nop->dev = dev;
249 nop->phy.dev = nop->dev;
250 nop->phy.label = "nop-xceiv";
251 nop->phy.set_suspend = nop_set_suspend;
252 nop->phy.type = type;
253
254 nop->phy.otg->state = OTG_STATE_UNDEFINED;
255 nop->phy.otg->usb_phy = &nop->phy;
256 nop->phy.otg->set_host = nop_set_host;
257 nop->phy.otg->set_peripheral = nop_set_peripheral;
258 nop->phy.otg->set_vbus = nop_set_vbus;
259
260 return 0;
261}
262EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
263
264static int usb_phy_generic_probe(struct platform_device *pdev)
265{
266 struct device *dev = &pdev->dev;
267 struct usb_phy_generic *nop;
268 int err;
269
270 nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
271 if (!nop)
272 return -ENOMEM;
273
274 err = usb_phy_gen_create_phy(dev, nop);
275 if (err)
276 return err;
277
278 if (nop->gpiod_vbus) {
279 err = devm_request_threaded_irq(dev,
280 gpiod_to_irq(nop->gpiod_vbus),
281 NULL, nop_gpio_vbus_thread,
282 VBUS_IRQ_FLAGS, "vbus_detect",
283 nop);
284 if (err)
285 return dev_err_probe(dev, err, "can't request irq %i\n",
286 gpiod_to_irq(nop->gpiod_vbus));
287
288 nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ?
289 OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE;
290 }
291
292 nop->phy.init = usb_gen_phy_init;
293 nop->phy.shutdown = usb_gen_phy_shutdown;
294
295 err = usb_add_phy_dev(&nop->phy);
296 if (err)
297 return dev_err_probe(dev, err, "can't register transceiver\n");
298
299 platform_set_drvdata(pdev, nop);
300
301 device_set_wakeup_capable(dev,
302 device_property_read_bool(dev, "wakeup-source"));
303
304 return 0;
305}
306
307static void usb_phy_generic_remove(struct platform_device *pdev)
308{
309 struct usb_phy_generic *nop = platform_get_drvdata(pdev);
310
311 usb_remove_phy(&nop->phy);
312
313 if (nop->vbus_draw && nop->vbus_draw_enabled)
314 regulator_disable(nop->vbus_draw);
315}
316
317static const struct of_device_id nop_xceiv_dt_ids[] = {
318 { .compatible = "usb-nop-xceiv" },
319 { }
320};
321
322MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
323
324static struct platform_driver usb_phy_generic_driver = {
325 .probe = usb_phy_generic_probe,
326 .remove = usb_phy_generic_remove,
327 .driver = {
328 .name = "usb_phy_generic",
329 .of_match_table = nop_xceiv_dt_ids,
330 },
331};
332
333static int __init usb_phy_generic_init(void)
334{
335 return platform_driver_register(&usb_phy_generic_driver);
336}
337subsys_initcall(usb_phy_generic_init);
338
339static void __exit usb_phy_generic_exit(void)
340{
341 platform_driver_unregister(&usb_phy_generic_driver);
342}
343module_exit(usb_phy_generic_exit);
344
345MODULE_ALIAS("platform:usb_phy_generic");
346MODULE_AUTHOR("Texas Instruments Inc");
347MODULE_DESCRIPTION("NOP USB Transceiver driver");
348MODULE_LICENSE("GPL");