summaryrefslogtreecommitdiff
path: root/drivers/usb/cdns3/drd.c
blob: 55c73b1d870471bff520b619fa27b6a94ee752d8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
// SPDX-License-Identifier: GPL-2.0
/*
 * Cadence USBSS and USBSSP DRD Driver.
 *
 * Copyright (C) 2018-2020 Cadence.
 * Copyright (C) 2019 Texas Instruments
 *
 * Author: Pawel Laszczak <pawell@cadence.com>
 *         Roger Quadros <rogerq@ti.com>
 *
 */
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/iopoll.h>
#include <linux/usb/otg.h>

#include "drd.h"
#include "core.h"

/**
 * cdns_set_mode - change mode of OTG Core
 * @cdns: pointer to context structure
 * @mode: selected mode from cdns_role
 *
 * Returns 0 on success otherwise negative errno
 */
static int cdns_set_mode(struct cdns *cdns, enum usb_dr_mode mode)
{
	void __iomem  *override_reg;
	u32 reg;

	switch (mode) {
	case USB_DR_MODE_PERIPHERAL:
		break;
	case USB_DR_MODE_HOST:
		break;
	case USB_DR_MODE_OTG:
		dev_dbg(cdns->dev, "Set controller to OTG mode\n");

		if (cdns->version == CDNSP_CONTROLLER_V2)
			override_reg = &cdns->otg_cdnsp_regs->override;
		else if (cdns->version == CDNS3_CONTROLLER_V1)
			override_reg = &cdns->otg_v1_regs->override;
		else
			override_reg = &cdns->otg_v0_regs->ctrl1;

		reg = readl(override_reg);

		if (cdns->version != CDNS3_CONTROLLER_V0)
			reg |= OVERRIDE_IDPULLUP;
		else
			reg |= OVERRIDE_IDPULLUP_V0;

		writel(reg, override_reg);

		if (cdns->version == CDNS3_CONTROLLER_V1) {
			/*
			 * Enable work around feature built into the
			 * controller to address issue with RX Sensitivity
			 * est (EL_17) for USB2 PHY. The issue only occures
			 * for 0x0002450D controller version.
			 */
			if (cdns->phyrst_a_enable) {
				reg = readl(&cdns->otg_v1_regs->phyrst_cfg);
				reg |= PHYRST_CFG_PHYRST_A_ENABLE;
				writel(reg, &cdns->otg_v1_regs->phyrst_cfg);
			}
		}

		/*
		 * Hardware specification says: "ID_VALUE must be valid within
		 * 50ms after idpullup is set to '1" so driver must wait
		 * 50ms before reading this pin.
		 */
		usleep_range(50000, 60000);
		break;
	default:
		dev_err(cdns->dev, "Unsupported mode of operation %d\n", mode);
		return -EINVAL;
	}

	return 0;
}

int cdns_get_id(struct cdns *cdns)
{
	int id;

	id = readl(&cdns->otg_regs->sts) & OTGSTS_ID_VALUE;
	dev_dbg(cdns->dev, "OTG ID: %d", id);

	return id;
}

int cdns_get_vbus(struct cdns *cdns)
{
	int vbus;

	vbus = !!(readl(&cdns->otg_regs->sts) & OTGSTS_VBUS_VALID);
	dev_dbg(cdns->dev, "OTG VBUS: %d", vbus);

	return vbus;
}

void cdns_clear_vbus(struct cdns *cdns)
{
	u32 reg;

	if (cdns->version != CDNSP_CONTROLLER_V2)
		return;

	reg = readl(&cdns->otg_cdnsp_regs->override);
	reg |= OVERRIDE_SESS_VLD_SEL;
	writel(reg, &cdns->otg_cdnsp_regs->override);
}
EXPORT_SYMBOL_GPL(cdns_clear_vbus);

void cdns_set_vbus(struct cdns *cdns)
{
	u32 reg;

	if (cdns->version != CDNSP_CONTROLLER_V2)
		return;

	reg = readl(&cdns->otg_cdnsp_regs->override);
	reg &= ~OVERRIDE_SESS_VLD_SEL;
	writel(reg, &cdns->otg_cdnsp_regs->override);
}
EXPORT_SYMBOL_GPL(cdns_set_vbus);

bool cdns_is_host(struct cdns *cdns)
{
	if (cdns->dr_mode == USB_DR_MODE_HOST)
		return true;
	else if (cdns_get_id(cdns) == CDNS3_ID_HOST)
		return true;

	return false;
}

bool cdns_is_device(struct cdns *cdns)
{
	if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL)
		return true;
	else if (cdns->dr_mode == USB_DR_MODE_OTG)
		if (cdns_get_id(cdns) == CDNS3_ID_PERIPHERAL)
			return true;

	return false;
}

/**
 * cdns_otg_disable_irq - Disable all OTG interrupts
 * @cdns: Pointer to controller context structure
 */
static void cdns_otg_disable_irq(struct cdns *cdns)
{
	writel(0, &cdns->otg_irq_regs->ien);
}

/**
 * cdns_otg_enable_irq - enable id and sess_valid interrupts
 * @cdns: Pointer to controller context structure
 */
static void cdns_otg_enable_irq(struct cdns *cdns)
{
	writel(OTGIEN_ID_CHANGE_INT | OTGIEN_VBUSVALID_RISE_INT |
	       OTGIEN_VBUSVALID_FALL_INT, &cdns->otg_irq_regs->ien);
}

/**
 * cdns_drd_host_on - start host.
 * @cdns: Pointer to controller context structure.
 *
 * Returns 0 on success otherwise negative errno.
 */
int cdns_drd_host_on(struct cdns *cdns)
{
	u32 val, ready_bit;
	int ret;

	/* Enable host mode. */
	writel(OTGCMD_HOST_BUS_REQ | OTGCMD_OTG_DIS,
	       &cdns->otg_regs->cmd);

	if (cdns->version == CDNSP_CONTROLLER_V2)
		ready_bit = OTGSTS_CDNSP_XHCI_READY;
	else
		ready_bit = OTGSTS_CDNS3_XHCI_READY;

	dev_dbg(cdns->dev, "Waiting till Host mode is turned on\n");
	ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val,
					val & ready_bit, 1, 100000);

	if (ret)
		dev_err(cdns->dev, "timeout waiting for xhci_ready\n");

	phy_set_mode(cdns->usb3_phy, PHY_MODE_USB_HOST);
	return ret;
}

/**
 * cdns_drd_host_off - stop host.
 * @cdns: Pointer to controller context structure.
 */
void cdns_drd_host_off(struct cdns *cdns)
{
	u32 val;

	writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
	       OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
	       &cdns->otg_regs->cmd);

	/* Waiting till H_IDLE state.*/
	readl_poll_timeout_atomic(&cdns->otg_regs->state, val,
				  !(val & OTGSTATE_HOST_STATE_MASK),
				  1, 2000000);
	phy_set_mode(cdns->usb3_phy, PHY_MODE_INVALID);
}

/**
 * cdns_drd_gadget_on - start gadget.
 * @cdns: Pointer to controller context structure.
 *
 * Returns 0 on success otherwise negative errno
 */
int cdns_drd_gadget_on(struct cdns *cdns)
{
	u32 reg = OTGCMD_OTG_DIS;
	u32 ready_bit;
	int ret, val;

	/* switch OTG core */
	writel(OTGCMD_DEV_BUS_REQ | reg, &cdns->otg_regs->cmd);

	dev_dbg(cdns->dev, "Waiting till Device mode is turned on\n");

	if (cdns->version == CDNSP_CONTROLLER_V2)
		ready_bit = OTGSTS_CDNSP_DEV_READY;
	else
		ready_bit = OTGSTS_CDNS3_DEV_READY;

	ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val,
					val & ready_bit, 1, 100000);
	if (ret) {
		dev_err(cdns->dev, "timeout waiting for dev_ready\n");
		return ret;
	}

	phy_set_mode(cdns->usb3_phy, PHY_MODE_USB_DEVICE);
	return 0;
}
EXPORT_SYMBOL_GPL(cdns_drd_gadget_on);

/**
 * cdns_drd_gadget_off - stop gadget.
 * @cdns: Pointer to controller context structure.
 */
void cdns_drd_gadget_off(struct cdns *cdns)
{
	u32 val;

	/*
	 * Driver should wait at least 10us after disabling Device
	 * before turning-off Device (DEV_BUS_DROP).
	 */
	usleep_range(20, 30);
	writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
	       OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
	       &cdns->otg_regs->cmd);
	/* Waiting till DEV_IDLE state.*/
	readl_poll_timeout_atomic(&cdns->otg_regs->state, val,
				  !(val & OTGSTATE_DEV_STATE_MASK),
				  1, 2000000);
	phy_set_mode(cdns->usb3_phy, PHY_MODE_INVALID);
}
EXPORT_SYMBOL_GPL(cdns_drd_gadget_off);

/**
 * cdns_init_otg_mode - initialize drd controller
 * @cdns: Pointer to controller context structure
 *
 * Returns 0 on success otherwise negative errno
 */
static int cdns_init_otg_mode(struct cdns *cdns)
{
	int ret;

	cdns_otg_disable_irq(cdns);
	/* clear all interrupts */
	writel(~0, &cdns->otg_irq_regs->ivect);

	ret = cdns_set_mode(cdns, USB_DR_MODE_OTG);
	if (ret)
		return ret;

	cdns_otg_enable_irq(cdns);

	return 0;
}

/**
 * cdns_drd_update_mode - initialize mode of operation
 * @cdns: Pointer to controller context structure
 *
 * Returns 0 on success otherwise negative errno
 */
int cdns_drd_update_mode(struct cdns *cdns)
{
	int ret;

	switch (cdns->dr_mode) {
	case USB_DR_MODE_PERIPHERAL:
		ret = cdns_set_mode(cdns, USB_DR_MODE_PERIPHERAL);
		break;
	case USB_DR_MODE_HOST:
		ret = cdns_set_mode(cdns, USB_DR_MODE_HOST);
		break;
	case USB_DR_MODE_OTG:
		ret = cdns_init_otg_mode(cdns);
		break;
	default:
		dev_err(cdns->dev, "Unsupported mode of operation %d\n",
			cdns->dr_mode);
		return -EINVAL;
	}

	return ret;
}

static irqreturn_t cdns_drd_thread_irq(int irq, void *data)
{
	struct cdns *cdns = data;

	cdns_hw_role_switch(cdns);

	return IRQ_HANDLED;
}

/**
 * cdns_drd_irq - interrupt handler for OTG events
 *
 * @irq: irq number for cdns core device
 * @data: structure of cdns
 *
 * Returns IRQ_HANDLED or IRQ_NONE
 */
static irqreturn_t cdns_drd_irq(int irq, void *data)
{
	irqreturn_t ret = IRQ_NONE;
	struct cdns *cdns = data;
	u32 reg;

	if (cdns->dr_mode != USB_DR_MODE_OTG)
		return IRQ_NONE;

	if (cdns->in_lpm)
		return ret;

	reg = readl(&cdns->otg_irq_regs->ivect);

	if (!reg)
		return IRQ_NONE;

	if (reg & OTGIEN_ID_CHANGE_INT) {
		dev_dbg(cdns->dev, "OTG IRQ: new ID: %d\n",
			cdns_get_id(cdns));

		ret = IRQ_WAKE_THREAD;
	}

	if (reg & (OTGIEN_VBUSVALID_RISE_INT | OTGIEN_VBUSVALID_FALL_INT)) {
		dev_dbg(cdns->dev, "OTG IRQ: new VBUS: %d\n",
			cdns_get_vbus(cdns));

		ret = IRQ_WAKE_THREAD;
	}

	writel(~0, &cdns->otg_irq_regs->ivect);
	return ret;
}

int cdns_drd_init(struct cdns *cdns)
{
	void __iomem *regs;
	u32 state;
	int ret;

	regs = devm_ioremap_resource(cdns->dev, &cdns->otg_res);
	if (IS_ERR(regs))
		return PTR_ERR(regs);

	/* Detection of DRD version. Controller has been released
	 * in three versions. All are very similar and are software compatible,
	 * but they have same changes in register maps.
	 * The first register in oldest version is command register and it's
	 * read only. Driver should read 0 from it. On the other hand, in v1
	 * and v2 the first register contains device ID number which is not
	 * set to 0. Driver uses this fact to detect the proper version of
	 * controller.
	 */
	cdns->otg_v0_regs = regs;
	if (!readl(&cdns->otg_v0_regs->cmd)) {
		cdns->version  = CDNS3_CONTROLLER_V0;
		cdns->otg_v1_regs = NULL;
		cdns->otg_cdnsp_regs = NULL;
		cdns->otg_regs = regs;
		cdns->otg_irq_regs = (struct cdns_otg_irq_regs __iomem  *)
				     &cdns->otg_v0_regs->ien;
		writel(1, &cdns->otg_v0_regs->simulate);
		dev_dbg(cdns->dev, "DRD version v0 (%08x)\n",
			 readl(&cdns->otg_v0_regs->version));
	} else {
		cdns->otg_v0_regs = NULL;
		cdns->otg_v1_regs = regs;
		cdns->otg_cdnsp_regs = regs;

		cdns->otg_regs = (void __iomem *)&cdns->otg_v1_regs->cmd;

		if (readl(&cdns->otg_cdnsp_regs->did) == OTG_CDNSP_DID) {
			cdns->otg_irq_regs = (struct cdns_otg_irq_regs __iomem *)
					      &cdns->otg_cdnsp_regs->ien;
			cdns->version  = CDNSP_CONTROLLER_V2;
		} else {
			cdns->otg_irq_regs = (struct cdns_otg_irq_regs __iomem *)
					      &cdns->otg_v1_regs->ien;
			writel(1, &cdns->otg_v1_regs->simulate);
			cdns->version  = CDNS3_CONTROLLER_V1;
		}

		dev_dbg(cdns->dev, "DRD version v1 (ID: %08x, rev: %08x)\n",
			 readl(&cdns->otg_v1_regs->did),
			 readl(&cdns->otg_v1_regs->rid));
	}

	state = OTGSTS_STRAP(readl(&cdns->otg_regs->sts));

	/* Update dr_mode according to STRAP configuration. */
	cdns->dr_mode = USB_DR_MODE_OTG;

	if ((cdns->version == CDNSP_CONTROLLER_V2 &&
	     state == OTGSTS_CDNSP_STRAP_HOST) ||
	    (cdns->version != CDNSP_CONTROLLER_V2 &&
	     state == OTGSTS_STRAP_HOST)) {
		dev_dbg(cdns->dev, "Controller strapped to HOST\n");
		cdns->dr_mode = USB_DR_MODE_HOST;
	} else if ((cdns->version == CDNSP_CONTROLLER_V2 &&
		    state == OTGSTS_CDNSP_STRAP_GADGET) ||
		   (cdns->version != CDNSP_CONTROLLER_V2 &&
		    state == OTGSTS_STRAP_GADGET)) {
		dev_dbg(cdns->dev, "Controller strapped to PERIPHERAL\n");
		cdns->dr_mode = USB_DR_MODE_PERIPHERAL;
	}

	ret = devm_request_threaded_irq(cdns->dev, cdns->otg_irq,
					cdns_drd_irq,
					cdns_drd_thread_irq,
					IRQF_SHARED,
					dev_name(cdns->dev), cdns);
	if (ret) {
		dev_err(cdns->dev, "couldn't get otg_irq\n");
		return ret;
	}

	state = readl(&cdns->otg_regs->sts);
	if (OTGSTS_OTG_NRDY(state)) {
		dev_err(cdns->dev, "Cadence USB3 OTG device not ready\n");
		return -ENODEV;
	}

	return 0;
}

int cdns_drd_exit(struct cdns *cdns)
{
	cdns_otg_disable_irq(cdns);

	return 0;
}


/* Indicate the cdns3 core was power lost before */
bool cdns_power_is_lost(struct cdns *cdns)
{
	if (cdns->version == CDNS3_CONTROLLER_V1) {
		if (!(readl(&cdns->otg_v1_regs->simulate) & BIT(0)))
			return true;
	} else {
		if (!(readl(&cdns->otg_v0_regs->simulate) & BIT(0)))
			return true;
	}
	return false;
}
EXPORT_SYMBOL_GPL(cdns_power_is_lost);