aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/mtu3/mtu3_dr.c
blob: 04f666e85731226d35fef1e1aea1af56c86d81cc (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
// SPDX-License-Identifier: GPL-2.0
/*
 * mtu3_dr.c - dual role switch and host glue layer
 *
 * Copyright (C) 2016 MediaTek Inc.
 *
 * Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
 */

#include <linux/usb/role.h>

#include "mtu3.h"
#include "mtu3_dr.h"
#include "mtu3_debug.h"

#define USB2_PORT 2
#define USB3_PORT 3

enum mtu3_vbus_id_state {
	MTU3_ID_FLOAT = 1,
	MTU3_ID_GROUND,
	MTU3_VBUS_OFF,
	MTU3_VBUS_VALID,
};

static char *mailbox_state_string(enum mtu3_vbus_id_state state)
{
	switch (state) {
	case MTU3_ID_FLOAT:
		return "ID_FLOAT";
	case MTU3_ID_GROUND:
		return "ID_GROUND";
	case MTU3_VBUS_OFF:
		return "VBUS_OFF";
	case MTU3_VBUS_VALID:
		return "VBUS_VALID";
	default:
		return "UNKNOWN";
	}
}

static void toggle_opstate(struct ssusb_mtk *ssusb)
{
	if (!ssusb->otg_switch.is_u3_drd) {
		mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION);
		mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN);
	}
}

/* only port0 supports dual-role mode */
static int ssusb_port0_switch(struct ssusb_mtk *ssusb,
	int version, bool tohost)
{
	void __iomem *ibase = ssusb->ippc_base;
	u32 value;

	dev_dbg(ssusb->dev, "%s (switch u%d port0 to %s)\n", __func__,
		version, tohost ? "host" : "device");

	if (version == USB2_PORT) {
		/* 1. power off and disable u2 port0 */
		value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
		value |= SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS;
		mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);

		/* 2. power on, enable u2 port0 and select its mode */
		value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
		value &= ~(SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS);
		value = tohost ? (value | SSUSB_U2_PORT_HOST_SEL) :
			(value & (~SSUSB_U2_PORT_HOST_SEL));
		mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
	} else {
		/* 1. power off and disable u3 port0 */
		value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
		value |= SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS;
		mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);

		/* 2. power on, enable u3 port0 and select its mode */
		value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
		value &= ~(SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS);
		value = tohost ? (value | SSUSB_U3_PORT_HOST_SEL) :
			(value & (~SSUSB_U3_PORT_HOST_SEL));
		mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
	}

	return 0;
}

static void switch_port_to_host(struct ssusb_mtk *ssusb)
{
	u32 check_clk = 0;

	dev_dbg(ssusb->dev, "%s\n", __func__);

	ssusb_port0_switch(ssusb, USB2_PORT, true);

	if (ssusb->otg_switch.is_u3_drd) {
		ssusb_port0_switch(ssusb, USB3_PORT, true);
		check_clk = SSUSB_U3_MAC_RST_B_STS;
	}

	ssusb_check_clocks(ssusb, check_clk);

	/* after all clocks are stable */
	toggle_opstate(ssusb);
}

static void switch_port_to_device(struct ssusb_mtk *ssusb)
{
	u32 check_clk = 0;

	dev_dbg(ssusb->dev, "%s\n", __func__);

	ssusb_port0_switch(ssusb, USB2_PORT, false);

	if (ssusb->otg_switch.is_u3_drd) {
		ssusb_port0_switch(ssusb, USB3_PORT, false);
		check_clk = SSUSB_U3_MAC_RST_B_STS;
	}

	ssusb_check_clocks(ssusb, check_clk);
}

int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on)
{
	struct ssusb_mtk *ssusb =
		container_of(otg_sx, struct ssusb_mtk, otg_switch);
	struct regulator *vbus = otg_sx->vbus;
	int ret;

	/* vbus is optional */
	if (!vbus)
		return 0;

	dev_dbg(ssusb->dev, "%s: turn %s\n", __func__, is_on ? "on" : "off");

	if (is_on) {
		ret = regulator_enable(vbus);
		if (ret) {
			dev_err(ssusb->dev, "vbus regulator enable failed\n");
			return ret;
		}
	} else {
		regulator_disable(vbus);
	}

	return 0;
}

/*
 * switch to host: -> MTU3_VBUS_OFF --> MTU3_ID_GROUND
 * switch to device: -> MTU3_ID_FLOAT --> MTU3_VBUS_VALID
 */
static void ssusb_set_mailbox(struct otg_switch_mtk *otg_sx,
	enum mtu3_vbus_id_state status)
{
	struct ssusb_mtk *ssusb =
		container_of(otg_sx, struct ssusb_mtk, otg_switch);
	struct mtu3 *mtu = ssusb->u3d;

	dev_dbg(ssusb->dev, "mailbox %s\n", mailbox_state_string(status));
	mtu3_dbg_trace(ssusb->dev, "mailbox %s", mailbox_state_string(status));

	switch (status) {
	case MTU3_ID_GROUND:
		switch_port_to_host(ssusb);
		ssusb_set_vbus(otg_sx, 1);
		ssusb->is_host = true;
		break;
	case MTU3_ID_FLOAT:
		ssusb->is_host = false;
		ssusb_set_vbus(otg_sx, 0);
		switch_port_to_device(ssusb);
		break;
	case MTU3_VBUS_OFF:
		mtu3_stop(mtu);
		pm_relax(ssusb->dev);
		break;
	case MTU3_VBUS_VALID:
		/* avoid suspend when works as device */
		pm_stay_awake(ssusb->dev);
		mtu3_start(mtu);
		break;
	default:
		dev_err(ssusb->dev, "invalid state\n");
	}
}

static void ssusb_id_work(struct work_struct *work)
{
	struct otg_switch_mtk *otg_sx =
		container_of(work, struct otg_switch_mtk, id_work);

	if (otg_sx->id_event)
		ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND);
	else
		ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
}

static void ssusb_vbus_work(struct work_struct *work)
{
	struct otg_switch_mtk *otg_sx =
		container_of(work, struct otg_switch_mtk, vbus_work);

	if (otg_sx->vbus_event)
		ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
	else
		ssusb_set_mailbox(otg_sx, MTU3_VBUS_OFF);
}

/*
 * @ssusb_id_notifier is called in atomic context, but @ssusb_set_mailbox
 * may sleep, so use work queue here
 */
static int ssusb_id_notifier(struct notifier_block *nb,
	unsigned long event, void *ptr)
{
	struct otg_switch_mtk *otg_sx =
		container_of(nb, struct otg_switch_mtk, id_nb);

	otg_sx->id_event = event;
	schedule_work(&otg_sx->id_work);

	return NOTIFY_DONE;
}

static int ssusb_vbus_notifier(struct notifier_block *nb,
	unsigned long event, void *ptr)
{
	struct otg_switch_mtk *otg_sx =
		container_of(nb, struct otg_switch_mtk, vbus_nb);

	otg_sx->vbus_event = event;
	schedule_work(&otg_sx->vbus_work);

	return NOTIFY_DONE;
}

static int ssusb_extcon_register(struct otg_switch_mtk *otg_sx)
{
	struct ssusb_mtk *ssusb =
		container_of(otg_sx, struct ssusb_mtk, otg_switch);
	struct extcon_dev *edev = otg_sx->edev;
	int ret;

	/* extcon is optional */
	if (!edev)
		return 0;

	otg_sx->vbus_nb.notifier_call = ssusb_vbus_notifier;
	ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB,
					&otg_sx->vbus_nb);
	if (ret < 0) {
		dev_err(ssusb->dev, "failed to register notifier for USB\n");
		return ret;
	}

	otg_sx->id_nb.notifier_call = ssusb_id_notifier;
	ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB_HOST,
					&otg_sx->id_nb);
	if (ret < 0) {
		dev_err(ssusb->dev, "failed to register notifier for USB-HOST\n");
		return ret;
	}

	dev_dbg(ssusb->dev, "EXTCON_USB: %d, EXTCON_USB_HOST: %d\n",
		extcon_get_state(edev, EXTCON_USB),
		extcon_get_state(edev, EXTCON_USB_HOST));

	/* default as host, switch to device mode if needed */
	if (extcon_get_state(edev, EXTCON_USB_HOST) == false)
		ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
	if (extcon_get_state(edev, EXTCON_USB) == true)
		ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);

	return 0;
}

/*
 * We provide an interface via debugfs to switch between host and device modes
 * depending on user input.
 * This is useful in special cases, such as uses TYPE-A receptacle but also
 * wants to support dual-role mode.
 */
void ssusb_mode_switch(struct ssusb_mtk *ssusb, int to_host)
{
	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;

	if (to_host) {
		ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_HOST);
		ssusb_set_mailbox(otg_sx, MTU3_VBUS_OFF);
		ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND);
	} else {
		ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_DEVICE);
		ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
		ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
	}
}

void ssusb_set_force_mode(struct ssusb_mtk *ssusb,
			  enum mtu3_dr_force_mode mode)
{
	u32 value;

	value = mtu3_readl(ssusb->ippc_base, SSUSB_U2_CTRL(0));
	switch (mode) {
	case MTU3_DR_FORCE_DEVICE:
		value |= SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG;
		break;
	case MTU3_DR_FORCE_HOST:
		value |= SSUSB_U2_PORT_FORCE_IDDIG;
		value &= ~SSUSB_U2_PORT_RG_IDDIG;
		break;
	case MTU3_DR_FORCE_NONE:
		value &= ~(SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG);
		break;
	default:
		return;
	}
	mtu3_writel(ssusb->ippc_base, SSUSB_U2_CTRL(0), value);
}

static int ssusb_role_sw_set(struct usb_role_switch *sw, enum usb_role role)
{
	struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
	bool to_host = false;

	if (role == USB_ROLE_HOST)
		to_host = true;

	if (to_host ^ ssusb->is_host)
		ssusb_mode_switch(ssusb, to_host);

	return 0;
}

static enum usb_role ssusb_role_sw_get(struct usb_role_switch *sw)
{
	struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
	enum usb_role role;

	role = ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE;

	return role;
}

static int ssusb_role_sw_register(struct otg_switch_mtk *otg_sx)
{
	struct usb_role_switch_desc role_sx_desc = { 0 };
	struct ssusb_mtk *ssusb =
		container_of(otg_sx, struct ssusb_mtk, otg_switch);

	if (!otg_sx->role_sw_used)
		return 0;

	role_sx_desc.set = ssusb_role_sw_set;
	role_sx_desc.get = ssusb_role_sw_get;
	role_sx_desc.fwnode = dev_fwnode(ssusb->dev);
	role_sx_desc.driver_data = ssusb;
	otg_sx->role_sw = usb_role_switch_register(ssusb->dev, &role_sx_desc);

	return PTR_ERR_OR_ZERO(otg_sx->role_sw);
}

int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)
{
	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
	int ret = 0;

	INIT_WORK(&otg_sx->id_work, ssusb_id_work);
	INIT_WORK(&otg_sx->vbus_work, ssusb_vbus_work);

	if (otg_sx->manual_drd_enabled)
		ssusb_dr_debugfs_init(ssusb);
	else if (otg_sx->role_sw_used)
		ret = ssusb_role_sw_register(otg_sx);
	else
		ret = ssusb_extcon_register(otg_sx);

	return ret;
}

void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb)
{
	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;

	cancel_work_sync(&otg_sx->id_work);
	cancel_work_sync(&otg_sx->vbus_work);
	usb_role_switch_unregister(otg_sx->role_sw);
}