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 enum mtu3_vbus_id_state {
26 static char *mailbox_state_string(enum mtu3_vbus_id_state state)
42 static void toggle_opstate(struct ssusb_mtk *ssusb)
44 if (!ssusb->otg_switch.is_u3_drd) {
45 mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION);
46 mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN);
50 /* only port0 supports dual-role mode */
51 static int ssusb_port0_switch(struct ssusb_mtk *ssusb,
52 int version, bool tohost)
54 void __iomem *ibase = ssusb->ippc_base;
57 dev_dbg(ssusb->dev, "%s (switch u%d port0 to %s)\n", __func__,
58 version, tohost ? "host" : "device");
60 if (version == USB2_PORT) {
61 /* 1. power off and disable u2 port0 */
62 value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
63 value |= SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS;
64 mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
66 /* 2. power on, enable u2 port0 and select its mode */
67 value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
68 value &= ~(SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS);
69 value = tohost ? (value | SSUSB_U2_PORT_HOST_SEL) :
70 (value & (~SSUSB_U2_PORT_HOST_SEL));
71 mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
73 /* 1. power off and disable u3 port0 */
74 value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
75 value |= SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS;
76 mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
78 /* 2. power on, enable u3 port0 and select its mode */
79 value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
80 value &= ~(SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS);
81 value = tohost ? (value | SSUSB_U3_PORT_HOST_SEL) :
82 (value & (~SSUSB_U3_PORT_HOST_SEL));
83 mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
89 static void switch_port_to_host(struct ssusb_mtk *ssusb)
93 dev_dbg(ssusb->dev, "%s\n", __func__);
95 ssusb_port0_switch(ssusb, USB2_PORT, true);
97 if (ssusb->otg_switch.is_u3_drd) {
98 ssusb_port0_switch(ssusb, USB3_PORT, true);
99 check_clk = SSUSB_U3_MAC_RST_B_STS;
102 ssusb_check_clocks(ssusb, check_clk);
104 /* after all clocks are stable */
105 toggle_opstate(ssusb);
108 static void switch_port_to_device(struct ssusb_mtk *ssusb)
112 dev_dbg(ssusb->dev, "%s\n", __func__);
114 ssusb_port0_switch(ssusb, USB2_PORT, false);
116 if (ssusb->otg_switch.is_u3_drd) {
117 ssusb_port0_switch(ssusb, USB3_PORT, false);
118 check_clk = SSUSB_U3_MAC_RST_B_STS;
121 ssusb_check_clocks(ssusb, check_clk);
124 int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on)
126 struct ssusb_mtk *ssusb =
127 container_of(otg_sx, struct ssusb_mtk, otg_switch);
128 struct regulator *vbus = otg_sx->vbus;
131 /* vbus is optional */
135 dev_dbg(ssusb->dev, "%s: turn %s\n", __func__, is_on ? "on" : "off");
138 ret = regulator_enable(vbus);
140 dev_err(ssusb->dev, "vbus regulator enable failed\n");
144 regulator_disable(vbus);
150 static void ssusb_set_mailbox(struct otg_switch_mtk *otg_sx,
151 enum mtu3_vbus_id_state status)
153 struct ssusb_mtk *ssusb =
154 container_of(otg_sx, struct ssusb_mtk, otg_switch);
155 struct mtu3 *mtu = ssusb->u3d;
157 dev_dbg(ssusb->dev, "mailbox %s\n", mailbox_state_string(status));
158 mtu3_dbg_trace(ssusb->dev, "mailbox %s", mailbox_state_string(status));
163 switch_port_to_host(ssusb);
164 ssusb_set_vbus(otg_sx, 1);
165 ssusb->is_host = true;
168 ssusb->is_host = false;
169 ssusb_set_vbus(otg_sx, 0);
170 switch_port_to_device(ssusb);
174 dev_err(ssusb->dev, "invalid state\n");
178 static void ssusb_id_work(struct work_struct *work)
180 struct otg_switch_mtk *otg_sx =
181 container_of(work, struct otg_switch_mtk, id_work);
183 if (otg_sx->id_event)
184 ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND);
186 ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
190 * @ssusb_id_notifier is called in atomic context, but @ssusb_set_mailbox
191 * may sleep, so use work queue here
193 static int ssusb_id_notifier(struct notifier_block *nb,
194 unsigned long event, void *ptr)
196 struct otg_switch_mtk *otg_sx =
197 container_of(nb, struct otg_switch_mtk, id_nb);
199 otg_sx->id_event = event;
200 schedule_work(&otg_sx->id_work);
205 static int ssusb_extcon_register(struct otg_switch_mtk *otg_sx)
207 struct ssusb_mtk *ssusb =
208 container_of(otg_sx, struct ssusb_mtk, otg_switch);
209 struct extcon_dev *edev = otg_sx->edev;
212 /* extcon is optional */
216 otg_sx->id_nb.notifier_call = ssusb_id_notifier;
217 ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB_HOST,
220 dev_err(ssusb->dev, "failed to register notifier for USB-HOST\n");
224 dev_dbg(ssusb->dev, "EXTCON_USB_HOST: %d\n",
225 extcon_get_state(edev, EXTCON_USB_HOST));
227 /* default as host, switch to device mode if needed */
228 if (extcon_get_state(edev, EXTCON_USB_HOST) == false)
229 ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
235 * We provide an interface via debugfs to switch between host and device modes
236 * depending on user input.
237 * This is useful in special cases, such as uses TYPE-A receptacle but also
238 * wants to support dual-role mode.
240 void ssusb_mode_switch(struct ssusb_mtk *ssusb, int to_host)
242 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
245 ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_HOST);
246 ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND);
248 ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_DEVICE);
249 ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
253 void ssusb_set_force_mode(struct ssusb_mtk *ssusb,
254 enum mtu3_dr_force_mode mode)
258 value = mtu3_readl(ssusb->ippc_base, SSUSB_U2_CTRL(0));
260 case MTU3_DR_FORCE_DEVICE:
261 value |= SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG;
263 case MTU3_DR_FORCE_HOST:
264 value |= SSUSB_U2_PORT_FORCE_IDDIG;
265 value &= ~SSUSB_U2_PORT_RG_IDDIG;
267 case MTU3_DR_FORCE_NONE:
268 value &= ~(SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG);
273 mtu3_writel(ssusb->ippc_base, SSUSB_U2_CTRL(0), value);
276 static int ssusb_role_sw_set(struct usb_role_switch *sw, enum usb_role role)
278 struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
279 bool to_host = false;
281 if (role == USB_ROLE_HOST)
284 if (to_host ^ ssusb->is_host)
285 ssusb_mode_switch(ssusb, to_host);
290 static enum usb_role ssusb_role_sw_get(struct usb_role_switch *sw)
292 struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
295 role = ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE;
300 static int ssusb_role_sw_register(struct otg_switch_mtk *otg_sx)
302 struct usb_role_switch_desc role_sx_desc = { 0 };
303 struct ssusb_mtk *ssusb =
304 container_of(otg_sx, struct ssusb_mtk, otg_switch);
306 if (!otg_sx->role_sw_used)
309 role_sx_desc.set = ssusb_role_sw_set;
310 role_sx_desc.get = ssusb_role_sw_get;
311 role_sx_desc.fwnode = dev_fwnode(ssusb->dev);
312 role_sx_desc.driver_data = ssusb;
313 otg_sx->role_sw = usb_role_switch_register(ssusb->dev, &role_sx_desc);
315 return PTR_ERR_OR_ZERO(otg_sx->role_sw);
318 int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)
320 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
323 INIT_WORK(&otg_sx->id_work, ssusb_id_work);
325 if (otg_sx->manual_drd_enabled)
326 ssusb_dr_debugfs_init(ssusb);
327 else if (otg_sx->role_sw_used)
328 ret = ssusb_role_sw_register(otg_sx);
330 ret = ssusb_extcon_register(otg_sx);
335 void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb)
337 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
339 cancel_work_sync(&otg_sx->id_work);
340 usb_role_switch_unregister(otg_sx->role_sw);