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
50 if (!IS_ERR(nop->clk)) {
51 if (suspend)
52 clk_disable_unprepare(nop->clk);
53 else
54 clk_prepare_enable(nop->clk);
55 }
56
57 return 0;
58 }
59
nop_reset(struct usb_phy_generic * nop)60 static void nop_reset(struct usb_phy_generic *nop)
61 {
62 if (!nop->gpiod_reset)
63 return;
64
65 gpiod_set_value_cansleep(nop->gpiod_reset, 1);
66 usleep_range(10000, 20000);
67 gpiod_set_value_cansleep(nop->gpiod_reset, 0);
68 }
69
70 /* interface to regulator framework */
nop_set_vbus_draw(struct usb_phy_generic * nop,unsigned mA)71 static void nop_set_vbus_draw(struct usb_phy_generic *nop, unsigned mA)
72 {
73 struct regulator *vbus_draw = nop->vbus_draw;
74 int enabled;
75 int ret;
76
77 if (!vbus_draw)
78 return;
79
80 enabled = nop->vbus_draw_enabled;
81 if (mA) {
82 regulator_set_current_limit(vbus_draw, 0, 1000 * mA);
83 if (!enabled) {
84 ret = regulator_enable(vbus_draw);
85 if (ret < 0)
86 return;
87 nop->vbus_draw_enabled = 1;
88 }
89 } else {
90 if (enabled) {
91 ret = regulator_disable(vbus_draw);
92 if (ret < 0)
93 return;
94 nop->vbus_draw_enabled = 0;
95 }
96 }
97 nop->mA = mA;
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 /* drawing a "unit load" is *always* OK, except for OTG */
118 nop_set_vbus_draw(nop, 100);
119
120 atomic_notifier_call_chain(&nop->phy.notifier, status,
121 otg->gadget);
122 } else {
123 nop_set_vbus_draw(nop, 0);
124
125 status = USB_EVENT_NONE;
126 otg->state = OTG_STATE_B_IDLE;
127 nop->phy.last_event = status;
128
129 atomic_notifier_call_chain(&nop->phy.notifier, status,
130 otg->gadget);
131 }
132 return IRQ_HANDLED;
133 }
134
usb_gen_phy_init(struct usb_phy * phy)135 int usb_gen_phy_init(struct usb_phy *phy)
136 {
137 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
138 int ret;
139
140 if (!IS_ERR(nop->vcc)) {
141 if (regulator_enable(nop->vcc))
142 dev_err(phy->dev, "Failed to enable power\n");
143 }
144
145 if (!IS_ERR(nop->clk)) {
146 ret = clk_prepare_enable(nop->clk);
147 if (ret)
148 return ret;
149 }
150
151 nop_reset(nop);
152
153 return 0;
154 }
155 EXPORT_SYMBOL_GPL(usb_gen_phy_init);
156
usb_gen_phy_shutdown(struct usb_phy * phy)157 void usb_gen_phy_shutdown(struct usb_phy *phy)
158 {
159 struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
160
161 gpiod_set_value_cansleep(nop->gpiod_reset, 1);
162
163 if (!IS_ERR(nop->clk))
164 clk_disable_unprepare(nop->clk);
165
166 if (!IS_ERR(nop->vcc)) {
167 if (regulator_disable(nop->vcc))
168 dev_err(phy->dev, "Failed to disable power\n");
169 }
170 }
171 EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
172
nop_set_peripheral(struct usb_otg * otg,struct usb_gadget * gadget)173 static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
174 {
175 if (!otg)
176 return -ENODEV;
177
178 if (!gadget) {
179 otg->gadget = NULL;
180 return -ENODEV;
181 }
182
183 otg->gadget = gadget;
184 if (otg->state == OTG_STATE_B_PERIPHERAL)
185 atomic_notifier_call_chain(&otg->usb_phy->notifier,
186 USB_EVENT_VBUS, otg->gadget);
187 else
188 otg->state = OTG_STATE_B_IDLE;
189 return 0;
190 }
191
nop_set_host(struct usb_otg * otg,struct usb_bus * host)192 static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
193 {
194 if (!otg)
195 return -ENODEV;
196
197 if (!host) {
198 otg->host = NULL;
199 return -ENODEV;
200 }
201
202 otg->host = host;
203 return 0;
204 }
205
usb_phy_gen_create_phy(struct device * dev,struct usb_phy_generic * nop)206 int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop)
207 {
208 enum usb_phy_type type = USB_PHY_TYPE_USB2;
209 int err = 0;
210
211 u32 clk_rate = 0;
212 bool needs_vcc = false, needs_clk = false;
213
214 if (dev->of_node) {
215 struct device_node *node = dev->of_node;
216
217 if (of_property_read_u32(node, "clock-frequency", &clk_rate))
218 clk_rate = 0;
219
220 needs_vcc = of_property_read_bool(node, "vcc-supply");
221 needs_clk = of_property_read_bool(node, "clocks");
222 }
223 nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset",
224 GPIOD_ASIS);
225 err = PTR_ERR_OR_ZERO(nop->gpiod_reset);
226 if (!err) {
227 nop->gpiod_vbus = devm_gpiod_get_optional(dev,
228 "vbus-detect",
229 GPIOD_ASIS);
230 err = PTR_ERR_OR_ZERO(nop->gpiod_vbus);
231 }
232
233 if (err == -EPROBE_DEFER)
234 return -EPROBE_DEFER;
235 if (err) {
236 dev_err(dev, "Error requesting RESET or VBUS GPIO\n");
237 return err;
238 }
239 if (nop->gpiod_reset)
240 gpiod_direction_output(nop->gpiod_reset, 1);
241
242 nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
243 GFP_KERNEL);
244 if (!nop->phy.otg)
245 return -ENOMEM;
246
247 nop->clk = devm_clk_get(dev, "main_clk");
248 if (IS_ERR(nop->clk)) {
249 dev_dbg(dev, "Can't get phy clock: %ld\n",
250 PTR_ERR(nop->clk));
251 if (needs_clk)
252 return PTR_ERR(nop->clk);
253 }
254
255 if (!IS_ERR(nop->clk) && clk_rate) {
256 err = clk_set_rate(nop->clk, clk_rate);
257 if (err) {
258 dev_err(dev, "Error setting clock rate\n");
259 return err;
260 }
261 }
262
263 nop->vcc = devm_regulator_get(dev, "vcc");
264 if (IS_ERR(nop->vcc)) {
265 dev_dbg(dev, "Error getting vcc regulator: %ld\n",
266 PTR_ERR(nop->vcc));
267 if (needs_vcc)
268 return -EPROBE_DEFER;
269 }
270
271 nop->dev = dev;
272 nop->phy.dev = nop->dev;
273 nop->phy.label = "nop-xceiv";
274 nop->phy.set_suspend = nop_set_suspend;
275 nop->phy.type = type;
276
277 nop->phy.otg->state = OTG_STATE_UNDEFINED;
278 nop->phy.otg->usb_phy = &nop->phy;
279 nop->phy.otg->set_host = nop_set_host;
280 nop->phy.otg->set_peripheral = nop_set_peripheral;
281
282 return 0;
283 }
284 EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
285
usb_phy_generic_probe(struct platform_device * pdev)286 static int usb_phy_generic_probe(struct platform_device *pdev)
287 {
288 struct device *dev = &pdev->dev;
289 struct usb_phy_generic *nop;
290 int err;
291
292 nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
293 if (!nop)
294 return -ENOMEM;
295
296 err = usb_phy_gen_create_phy(dev, nop);
297 if (err)
298 return err;
299 if (nop->gpiod_vbus) {
300 err = devm_request_threaded_irq(&pdev->dev,
301 gpiod_to_irq(nop->gpiod_vbus),
302 NULL, nop_gpio_vbus_thread,
303 VBUS_IRQ_FLAGS, "vbus_detect",
304 nop);
305 if (err) {
306 dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
307 gpiod_to_irq(nop->gpiod_vbus), err);
308 return err;
309 }
310 nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ?
311 OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE;
312 }
313
314 nop->phy.init = usb_gen_phy_init;
315 nop->phy.shutdown = usb_gen_phy_shutdown;
316
317 err = usb_add_phy_dev(&nop->phy);
318 if (err) {
319 dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
320 err);
321 return err;
322 }
323
324 platform_set_drvdata(pdev, nop);
325
326 return 0;
327 }
328
usb_phy_generic_remove(struct platform_device * pdev)329 static int 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 return 0;
336 }
337
338 static const struct of_device_id nop_xceiv_dt_ids[] = {
339 { .compatible = "usb-nop-xceiv" },
340 { }
341 };
342
343 MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
344
345 static struct platform_driver usb_phy_generic_driver = {
346 .probe = usb_phy_generic_probe,
347 .remove = usb_phy_generic_remove,
348 .driver = {
349 .name = "usb_phy_generic",
350 .of_match_table = nop_xceiv_dt_ids,
351 },
352 };
353
usb_phy_generic_init(void)354 static int __init usb_phy_generic_init(void)
355 {
356 return platform_driver_register(&usb_phy_generic_driver);
357 }
358 subsys_initcall(usb_phy_generic_init);
359
usb_phy_generic_exit(void)360 static void __exit usb_phy_generic_exit(void)
361 {
362 platform_driver_unregister(&usb_phy_generic_driver);
363 }
364 module_exit(usb_phy_generic_exit);
365
366 MODULE_ALIAS("platform:usb_phy_generic");
367 MODULE_AUTHOR("Texas Instruments Inc");
368 MODULE_DESCRIPTION("NOP USB Transceiver driver");
369 MODULE_LICENSE("GPL");
370
