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
usb_phy_generic_register(void)33 struct platform_device *usb_phy_generic_register(void)
34 {
35 return platform_device_register_simple("usb_phy_generic",
36 PLATFORM_DEVID_AUTO, NULL, 0);
37 }
38 EXPORT_SYMBOL_GPL(usb_phy_generic_register);
39
usb_phy_generic_unregister(struct platform_device * pdev)40 void usb_phy_generic_unregister(struct platform_device *pdev)
41 {
42 platform_device_unregister(pdev);
43 }
44 EXPORT_SYMBOL_GPL(usb_phy_generic_unregister);
45
nop_set_suspend(struct usb_phy * x,int suspend)46 static 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
nop_reset(struct usb_phy_generic * nop)66 static 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 */
nop_set_vbus(struct usb_otg * otg,bool enable)78 static 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
nop_gpio_vbus_thread(int irq,void * data)101 static 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
usb_gen_phy_init(struct usb_phy * phy)130 int 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 }
150 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
151
usb_gen_phy_shutdown(struct usb_phy * phy)152 void 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 }
166 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
167
nop_set_peripheral(struct usb_otg * otg,struct usb_gadget * gadget)168 static 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
nop_set_host(struct usb_otg * otg,struct usb_bus * host)187 static 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
usb_phy_gen_create_phy(struct device * dev,struct usb_phy_generic * nop)201 int 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 }
280 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
281
usb_phy_generic_probe(struct platform_device * pdev)282 static 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
usb_phy_generic_remove(struct platform_device * pdev)329 static 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
339 static const struct of_device_id nop_xceiv_dt_ids[] = {
340 { .compatible = "usb-nop-xceiv" },
341 { }
342 };
343
344 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
345
346 static 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
usb_phy_generic_init(void)355 static int __init usb_phy_generic_init(void)
356 {
357 return platform_driver_register(&usb_phy_generic_driver);
358 }
359 subsys_initcall(usb_phy_generic_init);
360
usb_phy_generic_exit(void)361 static void __exit usb_phy_generic_exit(void)
362 {
363 platform_driver_unregister(&usb_phy_generic_driver);
364 }
365 module_exit(usb_phy_generic_exit);
366
367 MODULE_ALIAS("platform:usb_phy_generic");
368 MODULE_AUTHOR("Texas Instruments Inc");
369 MODULE_DESCRIPTION("NOP USB Transceiver driver");
370 MODULE_LICENSE("GPL");
371