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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * mtu3_dr.c - dual role switch and host glue layer
4 *
5 * Copyright (C) 2016 MediaTek Inc.
6 *
7 * Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
8 */
9
10#include "mtu3.h"
11#include "mtu3_dr.h"
12#include "mtu3_debug.h"
13
14#define USB2_PORT 2
15#define USB3_PORT 3
16
17static inline struct ssusb_mtk *otg_sx_to_ssusb(struct otg_switch_mtk *otg_sx)
18{
19 return container_of(otg_sx, struct ssusb_mtk, otg_switch);
20}
21
22static void toggle_opstate(struct ssusb_mtk *ssusb)
23{
24 if (!ssusb->otg_switch.is_u3_drd) {
25 mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION);
26 mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN);
27 }
28}
29
30/* only port0 supports dual-role mode */
31static int ssusb_port0_switch(struct ssusb_mtk *ssusb,
32 int version, bool tohost)
33{
34 void __iomem *ibase = ssusb->ippc_base;
35 u32 value;
36
37 dev_dbg(ssusb->dev, "%s (switch u%d port0 to %s)\n", __func__,
38 version, tohost ? "host" : "device");
39
40 if (version == USB2_PORT) {
41 /* 1. power off and disable u2 port0 */
42 value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
43 value |= SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS;
44 mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
45
46 /* 2. power on, enable u2 port0 and select its mode */
47 value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
48 value &= ~(SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS);
49 value = tohost ? (value | SSUSB_U2_PORT_HOST_SEL) :
50 (value & (~SSUSB_U2_PORT_HOST_SEL));
51 mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
52 } else {
53 /* 1. power off and disable u3 port0 */
54 value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
55 value |= SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS;
56 mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
57
58 /* 2. power on, enable u3 port0 and select its mode */
59 value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
60 value &= ~(SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS);
61 value = tohost ? (value | SSUSB_U3_PORT_HOST_SEL) :
62 (value & (~SSUSB_U3_PORT_HOST_SEL));
63 mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
64 }
65
66 return 0;
67}
68
69static void switch_port_to_host(struct ssusb_mtk *ssusb)
70{
71 u32 check_clk = 0;
72
73 dev_dbg(ssusb->dev, "%s\n", __func__);
74
75 ssusb_port0_switch(ssusb, USB2_PORT, true);
76
77 if (ssusb->otg_switch.is_u3_drd) {
78 ssusb_port0_switch(ssusb, USB3_PORT, true);
79 check_clk = SSUSB_U3_MAC_RST_B_STS;
80 }
81
82 ssusb_check_clocks(ssusb, check_clk);
83
84 /* after all clocks are stable */
85 toggle_opstate(ssusb);
86}
87
88static void switch_port_to_device(struct ssusb_mtk *ssusb)
89{
90 u32 check_clk = 0;
91
92 dev_dbg(ssusb->dev, "%s\n", __func__);
93
94 ssusb_port0_switch(ssusb, USB2_PORT, false);
95
96 if (ssusb->otg_switch.is_u3_drd) {
97 ssusb_port0_switch(ssusb, USB3_PORT, false);
98 check_clk = SSUSB_U3_MAC_RST_B_STS;
99 }
100
101 ssusb_check_clocks(ssusb, check_clk);
102}
103
104int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on)
105{
106 struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
107 struct regulator *vbus = otg_sx->vbus;
108 int ret;
109
110 /* vbus is optional */
111 if (!vbus)
112 return 0;
113
114 dev_dbg(ssusb->dev, "%s: turn %s\n", __func__, is_on ? "on" : "off");
115
116 if (is_on) {
117 ret = regulator_enable(vbus);
118 if (ret) {
119 dev_err(ssusb->dev, "vbus regulator enable failed\n");
120 return ret;
121 }
122 } else {
123 regulator_disable(vbus);
124 }
125
126 return 0;
127}
128
129static void ssusb_mode_sw_work(struct work_struct *work)
130{
131 struct otg_switch_mtk *otg_sx =
132 container_of(work, struct otg_switch_mtk, dr_work);
133 struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
134 struct mtu3 *mtu = ssusb->u3d;
135 enum usb_role desired_role = otg_sx->desired_role;
136 enum usb_role current_role;
137
138 current_role = ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE;
139
140 if (desired_role == USB_ROLE_NONE)
141 desired_role = USB_ROLE_HOST;
142
143 if (current_role == desired_role)
144 return;
145
146 dev_dbg(ssusb->dev, "set role : %s\n", usb_role_string(desired_role));
147 mtu3_dbg_trace(ssusb->dev, "set role : %s", usb_role_string(desired_role));
148
149 switch (desired_role) {
150 case USB_ROLE_HOST:
151 ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_HOST);
152 mtu3_stop(mtu);
153 switch_port_to_host(ssusb);
154 ssusb_set_vbus(otg_sx, 1);
155 ssusb->is_host = true;
156 break;
157 case USB_ROLE_DEVICE:
158 ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_DEVICE);
159 ssusb->is_host = false;
160 ssusb_set_vbus(otg_sx, 0);
161 switch_port_to_device(ssusb);
162 mtu3_start(mtu);
163 break;
164 case USB_ROLE_NONE:
165 default:
166 dev_err(ssusb->dev, "invalid role\n");
167 }
168}
169
170static void ssusb_set_mode(struct otg_switch_mtk *otg_sx, enum usb_role role)
171{
172 struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
173
174 if (ssusb->dr_mode != USB_DR_MODE_OTG)
175 return;
176
177 otg_sx->desired_role = role;
178 queue_work(system_freezable_wq, &otg_sx->dr_work);
179}
180
181static int ssusb_id_notifier(struct notifier_block *nb,
182 unsigned long event, void *ptr)
183{
184 struct otg_switch_mtk *otg_sx =
185 container_of(nb, struct otg_switch_mtk, id_nb);
186
187 ssusb_set_mode(otg_sx, event ? USB_ROLE_HOST : USB_ROLE_DEVICE);
188
189 return NOTIFY_DONE;
190}
191
192static int ssusb_extcon_register(struct otg_switch_mtk *otg_sx)
193{
194 struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
195 struct extcon_dev *edev = otg_sx->edev;
196 int ret;
197
198 /* extcon is optional */
199 if (!edev)
200 return 0;
201
202 otg_sx->id_nb.notifier_call = ssusb_id_notifier;
203 ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB_HOST,
204 &otg_sx->id_nb);
205 if (ret < 0) {
206 dev_err(ssusb->dev, "failed to register notifier for USB-HOST\n");
207 return ret;
208 }
209
210 ret = extcon_get_state(edev, EXTCON_USB_HOST);
211 dev_dbg(ssusb->dev, "EXTCON_USB_HOST: %d\n", ret);
212
213 /* default as host, switch to device mode if needed */
214 if (!ret)
215 ssusb_set_mode(otg_sx, USB_ROLE_DEVICE);
216
217 return 0;
218}
219
220/*
221 * We provide an interface via debugfs to switch between host and device modes
222 * depending on user input.
223 * This is useful in special cases, such as uses TYPE-A receptacle but also
224 * wants to support dual-role mode.
225 */
226void ssusb_mode_switch(struct ssusb_mtk *ssusb, int to_host)
227{
228 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
229
230 ssusb_set_mode(otg_sx, to_host ? USB_ROLE_HOST : USB_ROLE_DEVICE);
231}
232
233void ssusb_set_force_mode(struct ssusb_mtk *ssusb,
234 enum mtu3_dr_force_mode mode)
235{
236 u32 value;
237
238 value = mtu3_readl(ssusb->ippc_base, SSUSB_U2_CTRL(0));
239 switch (mode) {
240 case MTU3_DR_FORCE_DEVICE:
241 value |= SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG;
242 break;
243 case MTU3_DR_FORCE_HOST:
244 value |= SSUSB_U2_PORT_FORCE_IDDIG;
245 value &= ~SSUSB_U2_PORT_RG_IDDIG;
246 break;
247 case MTU3_DR_FORCE_NONE:
248 value &= ~(SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG);
249 break;
250 default:
251 return;
252 }
253 mtu3_writel(ssusb->ippc_base, SSUSB_U2_CTRL(0), value);
254}
255
256static int ssusb_role_sw_set(struct usb_role_switch *sw, enum usb_role role)
257{
258 struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
259 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
260
261 ssusb_set_mode(otg_sx, role);
262
263 return 0;
264}
265
266static enum usb_role ssusb_role_sw_get(struct usb_role_switch *sw)
267{
268 struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
269
270 return ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE;
271}
272
273static int ssusb_role_sw_register(struct otg_switch_mtk *otg_sx)
274{
275 struct usb_role_switch_desc role_sx_desc = { 0 };
276 struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
277
278 if (!otg_sx->role_sw_used)
279 return 0;
280
281 role_sx_desc.set = ssusb_role_sw_set;
282 role_sx_desc.get = ssusb_role_sw_get;
283 role_sx_desc.fwnode = dev_fwnode(ssusb->dev);
284 role_sx_desc.driver_data = ssusb;
285 otg_sx->role_sw = usb_role_switch_register(ssusb->dev, &role_sx_desc);
286
287 return PTR_ERR_OR_ZERO(otg_sx->role_sw);
288}
289
290int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)
291{
292 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
293 int ret = 0;
294
295 INIT_WORK(&otg_sx->dr_work, ssusb_mode_sw_work);
296
297 if (otg_sx->manual_drd_enabled)
298 ssusb_dr_debugfs_init(ssusb);
299 else if (otg_sx->role_sw_used)
300 ret = ssusb_role_sw_register(otg_sx);
301 else
302 ret = ssusb_extcon_register(otg_sx);
303
304 return ret;
305}
306
307void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb)
308{
309 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
310
311 cancel_work_sync(&otg_sx->dr_work);
312 usb_role_switch_unregister(otg_sx->role_sw);
313}