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}
 75
 76/* interface to regulator framework */
 77static void nop_set_vbus_draw(struct usb_phy_generic *nop, unsigned mA)
 78{
 79	struct regulator *vbus_draw = nop->vbus_draw;
 80	int enabled;
 81	int ret;
 82
 83	if (!vbus_draw)
 84		return;
 85
 86	enabled = nop->vbus_draw_enabled;
 87	if (mA) {
 88		regulator_set_current_limit(vbus_draw, 0, 1000 * mA);
 89		if (!enabled) {
 90			ret = regulator_enable(vbus_draw);
 91			if (ret < 0)
 92				return;
 93			nop->vbus_draw_enabled = 1;
 94		}
 95	} else {
 96		if (enabled) {
 97			ret = regulator_disable(vbus_draw);
 98			if (ret < 0)
 99				return;
100			nop->vbus_draw_enabled = 0;
101		}
102	}
103	nop->mA = mA;
104}
105
106
107static irqreturn_t nop_gpio_vbus_thread(int irq, void *data)
108{
109	struct usb_phy_generic *nop = data;
110	struct usb_otg *otg = nop->phy.otg;
111	int vbus, status;
112
113	vbus = gpiod_get_value(nop->gpiod_vbus);
114	if ((vbus ^ nop->vbus) == 0)
115		return IRQ_HANDLED;
116	nop->vbus = vbus;
117
118	if (vbus) {
119		status = USB_EVENT_VBUS;
120		otg->state = OTG_STATE_B_PERIPHERAL;
121		nop->phy.last_event = status;
122
123		/* drawing a "unit load" is *always* OK, except for OTG */
124		nop_set_vbus_draw(nop, 100);
125
126		atomic_notifier_call_chain(&nop->phy.notifier, status,
127					   otg->gadget);
128	} else {
129		nop_set_vbus_draw(nop, 0);
130
131		status = USB_EVENT_NONE;
132		otg->state = OTG_STATE_B_IDLE;
133		nop->phy.last_event = status;
134
135		atomic_notifier_call_chain(&nop->phy.notifier, status,
136					   otg->gadget);
137	}
138	return IRQ_HANDLED;
139}
140
141int usb_gen_phy_init(struct usb_phy *phy)
142{
143	struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
144	int ret;
145
146	if (!IS_ERR(nop->vcc)) {
147		if (regulator_enable(nop->vcc))
148			dev_err(phy->dev, "Failed to enable power\n");
149	}
150
151	if (!IS_ERR(nop->clk)) {
152		ret = clk_prepare_enable(nop->clk);
153		if (ret)
154			return ret;
155	}
156
157	nop_reset(nop);
158
159	return 0;
160}
161EXPORT_SYMBOL_GPL(usb_gen_phy_init);
162
163void usb_gen_phy_shutdown(struct usb_phy *phy)
164{
165	struct usb_phy_generic *nop = dev_get_drvdata(phy->dev);
166
167	gpiod_set_value_cansleep(nop->gpiod_reset, 1);
168
169	if (!IS_ERR(nop->clk))
170		clk_disable_unprepare(nop->clk);
171
172	if (!IS_ERR(nop->vcc)) {
173		if (regulator_disable(nop->vcc))
174			dev_err(phy->dev, "Failed to disable power\n");
175	}
176}
177EXPORT_SYMBOL_GPL(usb_gen_phy_shutdown);
178
179static int nop_set_peripheral(struct usb_otg *otg, struct usb_gadget *gadget)
180{
181	if (!otg)
182		return -ENODEV;
183
184	if (!gadget) {
185		otg->gadget = NULL;
186		return -ENODEV;
187	}
188
189	otg->gadget = gadget;
190	if (otg->state == OTG_STATE_B_PERIPHERAL)
191		atomic_notifier_call_chain(&otg->usb_phy->notifier,
192					   USB_EVENT_VBUS, otg->gadget);
193	else
194		otg->state = OTG_STATE_B_IDLE;
195	return 0;
196}
197
198static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
199{
200	if (!otg)
201		return -ENODEV;
202
203	if (!host) {
204		otg->host = NULL;
205		return -ENODEV;
206	}
207
208	otg->host = host;
209	return 0;
210}
211
212int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop)
213{
214	enum usb_phy_type type = USB_PHY_TYPE_USB2;
215	int err = 0;
216
217	u32 clk_rate = 0;
218	bool needs_clk = false;
219
220	if (dev->of_node) {
221		struct device_node *node = dev->of_node;
222
223		if (of_property_read_u32(node, "clock-frequency", &clk_rate))
224			clk_rate = 0;
225
226		needs_clk = of_property_read_bool(node, "clocks");
227	}
228	nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset",
229						   GPIOD_ASIS);
230	err = PTR_ERR_OR_ZERO(nop->gpiod_reset);
231	if (!err) {
232		nop->gpiod_vbus = devm_gpiod_get_optional(dev,
233						 "vbus-detect",
234						 GPIOD_ASIS);
235		err = PTR_ERR_OR_ZERO(nop->gpiod_vbus);
236	}
237
238	if (err)
239		return dev_err_probe(dev, err,
240				     "Error requesting RESET or VBUS GPIO\n");
241	if (nop->gpiod_reset)
242		gpiod_direction_output(nop->gpiod_reset, 1);
243
244	nop->phy.otg = devm_kzalloc(dev, sizeof(*nop->phy.otg),
245			GFP_KERNEL);
246	if (!nop->phy.otg)
247		return -ENOMEM;
248
249	nop->clk = devm_clk_get(dev, "main_clk");
250	if (IS_ERR(nop->clk)) {
251		dev_dbg(dev, "Can't get phy clock: %ld\n",
252					PTR_ERR(nop->clk));
253		if (needs_clk)
254			return PTR_ERR(nop->clk);
255	}
256
257	if (!IS_ERR(nop->clk) && clk_rate) {
258		err = clk_set_rate(nop->clk, clk_rate);
259		if (err) {
260			dev_err(dev, "Error setting clock rate\n");
261			return err;
262		}
263	}
264
265	nop->vcc = devm_regulator_get_optional(dev, "vcc");
266	if (IS_ERR(nop->vcc) && PTR_ERR(nop->vcc) != -ENODEV)
267		return dev_err_probe(dev, PTR_ERR(nop->vcc),
268				     "could not get vcc regulator\n");
269
270	nop->vbus_draw = devm_regulator_get_exclusive(dev, "vbus");
271	if (PTR_ERR(nop->vbus_draw) == -ENODEV)
272		nop->vbus_draw = NULL;
273	if (IS_ERR(nop->vbus_draw))
274		return dev_err_probe(dev, PTR_ERR(nop->vbus_draw),
275				     "could not get vbus regulator\n");
276
277	nop->dev		= dev;
278	nop->phy.dev		= nop->dev;
279	nop->phy.label		= "nop-xceiv";
280	nop->phy.set_suspend	= nop_set_suspend;
281	nop->phy.type		= type;
282
283	nop->phy.otg->state		= OTG_STATE_UNDEFINED;
284	nop->phy.otg->usb_phy		= &nop->phy;
285	nop->phy.otg->set_host		= nop_set_host;
286	nop->phy.otg->set_peripheral	= nop_set_peripheral;
287
288	return 0;
289}
290EXPORT_SYMBOL_GPL(usb_phy_gen_create_phy);
291
292static int usb_phy_generic_probe(struct platform_device *pdev)
293{
294	struct device *dev = &pdev->dev;
295	struct device_node *dn = dev->of_node;
296	struct usb_phy_generic	*nop;
297	int err;
298
299	nop = devm_kzalloc(dev, sizeof(*nop), GFP_KERNEL);
300	if (!nop)
301		return -ENOMEM;
302
303	err = usb_phy_gen_create_phy(dev, nop);
304	if (err)
305		return err;
306	if (nop->gpiod_vbus) {
307		err = devm_request_threaded_irq(&pdev->dev,
308						gpiod_to_irq(nop->gpiod_vbus),
309						NULL, nop_gpio_vbus_thread,
310						VBUS_IRQ_FLAGS, "vbus_detect",
311						nop);
312		if (err) {
313			dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
314				gpiod_to_irq(nop->gpiod_vbus), err);
315			return err;
316		}
317		nop->phy.otg->state = gpiod_get_value(nop->gpiod_vbus) ?
318			OTG_STATE_B_PERIPHERAL : OTG_STATE_B_IDLE;
319	}
320
321	nop->phy.init		= usb_gen_phy_init;
322	nop->phy.shutdown	= usb_gen_phy_shutdown;
323
324	err = usb_add_phy_dev(&nop->phy);
325	if (err) {
326		dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
327			err);
328		return err;
329	}
330
331	platform_set_drvdata(pdev, nop);
332
333	device_set_wakeup_capable(&pdev->dev,
334				  of_property_read_bool(dn, "wakeup-source"));
335
336	return 0;
337}
338
339static void usb_phy_generic_remove(struct platform_device *pdev)
340{
341	struct usb_phy_generic *nop = platform_get_drvdata(pdev);
342
343	usb_remove_phy(&nop->phy);
344}
345
346static const struct of_device_id nop_xceiv_dt_ids[] = {
347	{ .compatible = "usb-nop-xceiv" },
348	{ }
349};
350
351MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
352
353static struct platform_driver usb_phy_generic_driver = {
354	.probe		= usb_phy_generic_probe,
355	.remove_new	= usb_phy_generic_remove,
356	.driver		= {
357		.name	= "usb_phy_generic",
358		.of_match_table = nop_xceiv_dt_ids,
359	},
360};
361
362static int __init usb_phy_generic_init(void)
363{
364	return platform_driver_register(&usb_phy_generic_driver);
365}
366subsys_initcall(usb_phy_generic_init);
367
368static void __exit usb_phy_generic_exit(void)
369{
370	platform_driver_unregister(&usb_phy_generic_driver);
371}
372module_exit(usb_phy_generic_exit);
373
374MODULE_ALIAS("platform:usb_phy_generic");
375MODULE_AUTHOR("Texas Instruments Inc");
376MODULE_DESCRIPTION("NOP USB Transceiver driver");
377MODULE_LICENSE("GPL");