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
otg_sx_to_ssusb(struct otg_switch_mtk * otg_sx)17 static 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
toggle_opstate(struct ssusb_mtk * ssusb)22 static void toggle_opstate(struct ssusb_mtk *ssusb)
23 {
24 mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION);
25 mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN);
26 }
27
28 /* only port0 supports dual-role mode */
ssusb_port0_switch(struct ssusb_mtk * ssusb,int version,bool tohost)29 static int ssusb_port0_switch(struct ssusb_mtk *ssusb,
30 int version, bool tohost)
31 {
32 void __iomem *ibase = ssusb->ippc_base;
33 u32 value;
34
35 dev_dbg(ssusb->dev, "%s (switch u%d port0 to %s)\n", __func__,
36 version, tohost ? "host" : "device");
37
38 if (version == USB2_PORT) {
39 /* 1. power off and disable u2 port0 */
40 value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
41 value |= SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS;
42 mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
43
44 /* 2. power on, enable u2 port0 and select its mode */
45 value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
46 value &= ~(SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS);
47 value = tohost ? (value | SSUSB_U2_PORT_HOST_SEL) :
48 (value & (~SSUSB_U2_PORT_HOST_SEL));
49 mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
50 } else {
51 /* 1. power off and disable u3 port0 */
52 value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
53 value |= SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS;
54 mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
55
56 /* 2. power on, enable u3 port0 and select its mode */
57 value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
58 value &= ~(SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS);
59 value = tohost ? (value | SSUSB_U3_PORT_HOST_SEL) :
60 (value & (~SSUSB_U3_PORT_HOST_SEL));
61 mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
62 }
63
64 return 0;
65 }
66
switch_port_to_host(struct ssusb_mtk * ssusb)67 static void switch_port_to_host(struct ssusb_mtk *ssusb)
68 {
69 u32 check_clk = 0;
70
71 dev_dbg(ssusb->dev, "%s\n", __func__);
72
73 ssusb_port0_switch(ssusb, USB2_PORT, true);
74
75 if (ssusb->otg_switch.is_u3_drd) {
76 ssusb_port0_switch(ssusb, USB3_PORT, true);
77 check_clk = SSUSB_U3_MAC_RST_B_STS;
78 }
79
80 ssusb_check_clocks(ssusb, check_clk);
81
82 /* after all clocks are stable */
83 toggle_opstate(ssusb);
84 }
85
switch_port_to_device(struct ssusb_mtk * ssusb)86 static void switch_port_to_device(struct ssusb_mtk *ssusb)
87 {
88 u32 check_clk = 0;
89
90 dev_dbg(ssusb->dev, "%s\n", __func__);
91
92 ssusb_port0_switch(ssusb, USB2_PORT, false);
93
94 if (ssusb->otg_switch.is_u3_drd) {
95 ssusb_port0_switch(ssusb, USB3_PORT, false);
96 check_clk = SSUSB_U3_MAC_RST_B_STS;
97 }
98
99 ssusb_check_clocks(ssusb, check_clk);
100 }
101
ssusb_set_vbus(struct otg_switch_mtk * otg_sx,int is_on)102 int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on)
103 {
104 struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
105 struct regulator *vbus = otg_sx->vbus;
106 int ret;
107
108 /* vbus is optional */
109 if (!vbus)
110 return 0;
111
112 dev_dbg(ssusb->dev, "%s: turn %s\n", __func__, is_on ? "on" : "off");
113
114 if (is_on) {
115 ret = regulator_enable(vbus);
116 if (ret) {
117 dev_err(ssusb->dev, "vbus regulator enable failed\n");
118 return ret;
119 }
120 } else {
121 regulator_disable(vbus);
122 }
123
124 return 0;
125 }
126
ssusb_mode_sw_work(struct work_struct * work)127 static void ssusb_mode_sw_work(struct work_struct *work)
128 {
129 struct otg_switch_mtk *otg_sx =
130 container_of(work, struct otg_switch_mtk, dr_work);
131 struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
132 struct mtu3 *mtu = ssusb->u3d;
133 enum usb_role desired_role = otg_sx->desired_role;
134 enum usb_role current_role;
135
136 current_role = ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE;
137
138 if (desired_role == USB_ROLE_NONE) {
139 /* the default mode is host as probe does */
140 desired_role = USB_ROLE_HOST;
141 if (otg_sx->default_role == USB_ROLE_DEVICE)
142 desired_role = USB_ROLE_DEVICE;
143 }
144
145 if (current_role == desired_role)
146 return;
147
148 dev_dbg(ssusb->dev, "set role : %s\n", usb_role_string(desired_role));
149 mtu3_dbg_trace(ssusb->dev, "set role : %s", usb_role_string(desired_role));
150 pm_runtime_get_sync(ssusb->dev);
151
152 switch (desired_role) {
153 case USB_ROLE_HOST:
154 ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_HOST);
155 mtu3_stop(mtu);
156 switch_port_to_host(ssusb);
157 ssusb_set_vbus(otg_sx, 1);
158 ssusb->is_host = true;
159 break;
160 case USB_ROLE_DEVICE:
161 ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_DEVICE);
162 ssusb->is_host = false;
163 ssusb_set_vbus(otg_sx, 0);
164 switch_port_to_device(ssusb);
165 mtu3_start(mtu);
166 break;
167 case USB_ROLE_NONE:
168 default:
169 dev_err(ssusb->dev, "invalid role\n");
170 }
171 pm_runtime_put(ssusb->dev);
172 }
173
ssusb_set_mode(struct otg_switch_mtk * otg_sx,enum usb_role role)174 static void ssusb_set_mode(struct otg_switch_mtk *otg_sx, enum usb_role role)
175 {
176 struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
177
178 if (ssusb->dr_mode != USB_DR_MODE_OTG)
179 return;
180
181 otg_sx->desired_role = role;
182 queue_work(system_freezable_wq, &otg_sx->dr_work);
183 }
184
ssusb_id_notifier(struct notifier_block * nb,unsigned long event,void * ptr)185 static int ssusb_id_notifier(struct notifier_block *nb,
186 unsigned long event, void *ptr)
187 {
188 struct otg_switch_mtk *otg_sx =
189 container_of(nb, struct otg_switch_mtk, id_nb);
190
191 ssusb_set_mode(otg_sx, event ? USB_ROLE_HOST : USB_ROLE_DEVICE);
192
193 return NOTIFY_DONE;
194 }
195
ssusb_extcon_register(struct otg_switch_mtk * otg_sx)196 static int ssusb_extcon_register(struct otg_switch_mtk *otg_sx)
197 {
198 struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
199 struct extcon_dev *edev = otg_sx->edev;
200 int ret;
201
202 /* extcon is optional */
203 if (!edev)
204 return 0;
205
206 otg_sx->id_nb.notifier_call = ssusb_id_notifier;
207 ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB_HOST,
208 &otg_sx->id_nb);
209 if (ret < 0) {
210 dev_err(ssusb->dev, "failed to register notifier for USB-HOST\n");
211 return ret;
212 }
213
214 ret = extcon_get_state(edev, EXTCON_USB_HOST);
215 dev_dbg(ssusb->dev, "EXTCON_USB_HOST: %d\n", ret);
216
217 /* default as host, switch to device mode if needed */
218 if (!ret)
219 ssusb_set_mode(otg_sx, USB_ROLE_DEVICE);
220
221 return 0;
222 }
223
224 /*
225 * We provide an interface via debugfs to switch between host and device modes
226 * depending on user input.
227 * This is useful in special cases, such as uses TYPE-A receptacle but also
228 * wants to support dual-role mode.
229 */
ssusb_mode_switch(struct ssusb_mtk * ssusb,int to_host)230 void ssusb_mode_switch(struct ssusb_mtk *ssusb, int to_host)
231 {
232 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
233
234 ssusb_set_mode(otg_sx, to_host ? USB_ROLE_HOST : USB_ROLE_DEVICE);
235 }
236
ssusb_set_force_mode(struct ssusb_mtk * ssusb,enum mtu3_dr_force_mode mode)237 void ssusb_set_force_mode(struct ssusb_mtk *ssusb,
238 enum mtu3_dr_force_mode mode)
239 {
240 u32 value;
241
242 value = mtu3_readl(ssusb->ippc_base, SSUSB_U2_CTRL(0));
243 switch (mode) {
244 case MTU3_DR_FORCE_DEVICE:
245 value |= SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG;
246 break;
247 case MTU3_DR_FORCE_HOST:
248 value |= SSUSB_U2_PORT_FORCE_IDDIG;
249 value &= ~SSUSB_U2_PORT_RG_IDDIG;
250 break;
251 case MTU3_DR_FORCE_NONE:
252 value &= ~(SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG);
253 break;
254 default:
255 return;
256 }
257 mtu3_writel(ssusb->ippc_base, SSUSB_U2_CTRL(0), value);
258 }
259
ssusb_role_sw_set(struct usb_role_switch * sw,enum usb_role role)260 static int ssusb_role_sw_set(struct usb_role_switch *sw, enum usb_role role)
261 {
262 struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
263 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
264
265 ssusb_set_mode(otg_sx, role);
266
267 return 0;
268 }
269
ssusb_role_sw_get(struct usb_role_switch * sw)270 static enum usb_role ssusb_role_sw_get(struct usb_role_switch *sw)
271 {
272 struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
273
274 return ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE;
275 }
276
ssusb_role_sw_register(struct otg_switch_mtk * otg_sx)277 static int ssusb_role_sw_register(struct otg_switch_mtk *otg_sx)
278 {
279 struct usb_role_switch_desc role_sx_desc = { 0 };
280 struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
281 struct device *dev = ssusb->dev;
282 enum usb_dr_mode mode;
283
284 if (!otg_sx->role_sw_used)
285 return 0;
286
287 mode = usb_get_role_switch_default_mode(dev);
288 if (mode == USB_DR_MODE_PERIPHERAL)
289 otg_sx->default_role = USB_ROLE_DEVICE;
290 else
291 otg_sx->default_role = USB_ROLE_HOST;
292
293 role_sx_desc.set = ssusb_role_sw_set;
294 role_sx_desc.get = ssusb_role_sw_get;
295 role_sx_desc.fwnode = dev_fwnode(dev);
296 role_sx_desc.driver_data = ssusb;
297 role_sx_desc.allow_userspace_control = true;
298 otg_sx->role_sw = usb_role_switch_register(dev, &role_sx_desc);
299 if (IS_ERR(otg_sx->role_sw))
300 return PTR_ERR(otg_sx->role_sw);
301
302 ssusb_set_mode(otg_sx, otg_sx->default_role);
303
304 return 0;
305 }
306
ssusb_otg_switch_init(struct ssusb_mtk * ssusb)307 int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)
308 {
309 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
310 int ret = 0;
311
312 INIT_WORK(&otg_sx->dr_work, ssusb_mode_sw_work);
313
314 if (otg_sx->manual_drd_enabled)
315 ssusb_dr_debugfs_init(ssusb);
316 else if (otg_sx->role_sw_used)
317 ret = ssusb_role_sw_register(otg_sx);
318 else
319 ret = ssusb_extcon_register(otg_sx);
320
321 return ret;
322 }
323
ssusb_otg_switch_exit(struct ssusb_mtk * ssusb)324 void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb)
325 {
326 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
327
328 cancel_work_sync(&otg_sx->dr_work);
329 usb_role_switch_unregister(otg_sx->role_sw);
330 }
331