1 // SPDX-License-Identifier: GPL-2.0
3 * mtu3_dr.c - dual role switch and host glue layer
5 * Copyright (C) 2016 MediaTek Inc.
7 * Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
10 #include <linux/usb/role.h>
14 #include "mtu3_debug.h"
19 static void toggle_opstate(struct ssusb_mtk *ssusb)
21 if (!ssusb->otg_switch.is_u3_drd) {
22 mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION);
23 mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN);
27 /* only port0 supports dual-role mode */
28 static int ssusb_port0_switch(struct ssusb_mtk *ssusb,
29 int version, bool tohost)
31 void __iomem *ibase = ssusb->ippc_base;
34 dev_dbg(ssusb->dev, "%s (switch u%d port0 to %s)\n", __func__,
35 version, tohost ? "host" : "device");
37 if (version == USB2_PORT) {
38 /* 1. power off and disable u2 port0 */
39 value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
40 value |= SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS;
41 mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
43 /* 2. power on, enable u2 port0 and select its mode */
44 value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
45 value &= ~(SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS);
46 value = tohost ? (value | SSUSB_U2_PORT_HOST_SEL) :
47 (value & (~SSUSB_U2_PORT_HOST_SEL));
48 mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
50 /* 1. power off and disable u3 port0 */
51 value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
52 value |= SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS;
53 mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
55 /* 2. power on, enable u3 port0 and select its mode */
56 value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
57 value &= ~(SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS);
58 value = tohost ? (value | SSUSB_U3_PORT_HOST_SEL) :
59 (value & (~SSUSB_U3_PORT_HOST_SEL));
60 mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
66 static void switch_port_to_host(struct ssusb_mtk *ssusb)
70 dev_dbg(ssusb->dev, "%s\n", __func__);
72 ssusb_port0_switch(ssusb, USB2_PORT, true);
74 if (ssusb->otg_switch.is_u3_drd) {
75 ssusb_port0_switch(ssusb, USB3_PORT, true);
76 check_clk = SSUSB_U3_MAC_RST_B_STS;
79 ssusb_check_clocks(ssusb, check_clk);
81 /* after all clocks are stable */
82 toggle_opstate(ssusb);
85 static void switch_port_to_device(struct ssusb_mtk *ssusb)
89 dev_dbg(ssusb->dev, "%s\n", __func__);
91 ssusb_port0_switch(ssusb, USB2_PORT, false);
93 if (ssusb->otg_switch.is_u3_drd) {
94 ssusb_port0_switch(ssusb, USB3_PORT, false);
95 check_clk = SSUSB_U3_MAC_RST_B_STS;
98 ssusb_check_clocks(ssusb, check_clk);
101 int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on)
103 struct ssusb_mtk *ssusb =
104 container_of(otg_sx, struct ssusb_mtk, otg_switch);
105 struct regulator *vbus = otg_sx->vbus;
108 /* vbus is optional */
112 dev_dbg(ssusb->dev, "%s: turn %s\n", __func__, is_on ? "on" : "off");
115 ret = regulator_enable(vbus);
117 dev_err(ssusb->dev, "vbus regulator enable failed\n");
121 regulator_disable(vbus);
127 static void ssusb_set_role(struct otg_switch_mtk *otg_sx, enum usb_role role)
129 struct ssusb_mtk *ssusb =
130 container_of(otg_sx, struct ssusb_mtk, otg_switch);
131 struct mtu3 *mtu = ssusb->u3d;
133 dev_dbg(ssusb->dev, "set role : %d\n", role);
134 mtu3_dbg_trace(ssusb->dev, "set role : %d", role);
139 switch_port_to_host(ssusb);
140 ssusb_set_vbus(otg_sx, 1);
141 ssusb->is_host = true;
143 case USB_ROLE_DEVICE:
144 ssusb->is_host = false;
145 ssusb_set_vbus(otg_sx, 0);
146 switch_port_to_device(ssusb);
152 dev_err(ssusb->dev, "invalid role\n");
156 static void ssusb_id_work(struct work_struct *work)
158 struct otg_switch_mtk *otg_sx =
159 container_of(work, struct otg_switch_mtk, id_work);
161 if (otg_sx->id_event)
162 ssusb_set_role(otg_sx, USB_ROLE_HOST);
164 ssusb_set_role(otg_sx, USB_ROLE_DEVICE);
168 * @ssusb_id_notifier is called in atomic context, but ssusb_set_role()
169 * may sleep, so use work queue here
171 static int ssusb_id_notifier(struct notifier_block *nb,
172 unsigned long event, void *ptr)
174 struct otg_switch_mtk *otg_sx =
175 container_of(nb, struct otg_switch_mtk, id_nb);
177 otg_sx->id_event = event;
178 schedule_work(&otg_sx->id_work);
183 static int ssusb_extcon_register(struct otg_switch_mtk *otg_sx)
185 struct ssusb_mtk *ssusb =
186 container_of(otg_sx, struct ssusb_mtk, otg_switch);
187 struct extcon_dev *edev = otg_sx->edev;
190 /* extcon is optional */
194 otg_sx->id_nb.notifier_call = ssusb_id_notifier;
195 ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB_HOST,
198 dev_err(ssusb->dev, "failed to register notifier for USB-HOST\n");
202 dev_dbg(ssusb->dev, "EXTCON_USB_HOST: %d\n",
203 extcon_get_state(edev, EXTCON_USB_HOST));
205 /* default as host, switch to device mode if needed */
206 if (extcon_get_state(edev, EXTCON_USB_HOST) == false)
207 ssusb_set_role(otg_sx, USB_ROLE_DEVICE);
213 * We provide an interface via debugfs to switch between host and device modes
214 * depending on user input.
215 * This is useful in special cases, such as uses TYPE-A receptacle but also
216 * wants to support dual-role mode.
218 void ssusb_mode_switch(struct ssusb_mtk *ssusb, int to_host)
220 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
223 ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_HOST);
224 ssusb_set_role(otg_sx, USB_ROLE_HOST);
226 ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_DEVICE);
227 ssusb_set_role(otg_sx, USB_ROLE_DEVICE);
231 void ssusb_set_force_mode(struct ssusb_mtk *ssusb,
232 enum mtu3_dr_force_mode mode)
236 value = mtu3_readl(ssusb->ippc_base, SSUSB_U2_CTRL(0));
238 case MTU3_DR_FORCE_DEVICE:
239 value |= SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG;
241 case MTU3_DR_FORCE_HOST:
242 value |= SSUSB_U2_PORT_FORCE_IDDIG;
243 value &= ~SSUSB_U2_PORT_RG_IDDIG;
245 case MTU3_DR_FORCE_NONE:
246 value &= ~(SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG);
251 mtu3_writel(ssusb->ippc_base, SSUSB_U2_CTRL(0), value);
254 static int ssusb_role_sw_set(struct usb_role_switch *sw, enum usb_role role)
256 struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
257 bool to_host = false;
259 if (role == USB_ROLE_HOST)
262 if (to_host ^ ssusb->is_host)
263 ssusb_mode_switch(ssusb, to_host);
268 static enum usb_role ssusb_role_sw_get(struct usb_role_switch *sw)
270 struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
273 role = ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE;
278 static int ssusb_role_sw_register(struct otg_switch_mtk *otg_sx)
280 struct usb_role_switch_desc role_sx_desc = { 0 };
281 struct ssusb_mtk *ssusb =
282 container_of(otg_sx, struct ssusb_mtk, otg_switch);
284 if (!otg_sx->role_sw_used)
287 role_sx_desc.set = ssusb_role_sw_set;
288 role_sx_desc.get = ssusb_role_sw_get;
289 role_sx_desc.fwnode = dev_fwnode(ssusb->dev);
290 role_sx_desc.driver_data = ssusb;
291 otg_sx->role_sw = usb_role_switch_register(ssusb->dev, &role_sx_desc);
293 return PTR_ERR_OR_ZERO(otg_sx->role_sw);
296 int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)
298 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
301 INIT_WORK(&otg_sx->id_work, ssusb_id_work);
303 if (otg_sx->manual_drd_enabled)
304 ssusb_dr_debugfs_init(ssusb);
305 else if (otg_sx->role_sw_used)
306 ret = ssusb_role_sw_register(otg_sx);
308 ret = ssusb_extcon_register(otg_sx);
313 void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb)
315 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
317 cancel_work_sync(&otg_sx->id_work);
318 usb_role_switch_unregister(otg_sx->role_sw);