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/debugfs.h>
11 #include <linux/irq.h>
12 #include <linux/kernel.h>
13 #include <linux/of_device.h>
14 #include <linux/pinctrl/consumer.h>
15 #include <linux/seq_file.h>
16 #include <linux/uaccess.h>
24 enum mtu3_vbus_id_state {
31 static void toggle_opstate(struct ssusb_mtk *ssusb)
33 mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION);
34 mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN);
37 /* only port0 supports dual-role mode */
38 static int ssusb_port0_switch(struct ssusb_mtk *ssusb,
39 int version, bool tohost)
41 void __iomem *ibase = ssusb->ippc_base;
44 dev_dbg(ssusb->dev, "%s (switch u%d port0 to %s)\n", __func__,
45 version, tohost ? "host" : "device");
47 if (version == USB2_PORT) {
48 /* 1. power off and disable u2 port0 */
49 value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
50 value |= SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS;
51 mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
53 /* 2. power on, enable u2 port0 and select its mode */
54 value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
55 value &= ~(SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS);
56 value = tohost ? (value | SSUSB_U2_PORT_HOST_SEL) :
57 (value & (~SSUSB_U2_PORT_HOST_SEL));
58 mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
60 /* 1. power off and disable u3 port0 */
61 value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
62 value |= SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS;
63 mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
65 /* 2. power on, enable u3 port0 and select its mode */
66 value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
67 value &= ~(SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS);
68 value = tohost ? (value | SSUSB_U3_PORT_HOST_SEL) :
69 (value & (~SSUSB_U3_PORT_HOST_SEL));
70 mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
76 static void switch_port_to_host(struct ssusb_mtk *ssusb)
80 dev_dbg(ssusb->dev, "%s\n", __func__);
82 ssusb_port0_switch(ssusb, USB2_PORT, true);
84 if (ssusb->otg_switch.is_u3_drd) {
85 ssusb_port0_switch(ssusb, USB3_PORT, true);
86 check_clk = SSUSB_U3_MAC_RST_B_STS;
89 ssusb_check_clocks(ssusb, check_clk);
91 /* after all clocks are stable */
92 toggle_opstate(ssusb);
95 static void switch_port_to_device(struct ssusb_mtk *ssusb)
99 dev_dbg(ssusb->dev, "%s\n", __func__);
101 ssusb_port0_switch(ssusb, USB2_PORT, false);
103 if (ssusb->otg_switch.is_u3_drd) {
104 ssusb_port0_switch(ssusb, USB3_PORT, false);
105 check_clk = SSUSB_U3_MAC_RST_B_STS;
108 ssusb_check_clocks(ssusb, check_clk);
111 int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on)
113 struct ssusb_mtk *ssusb =
114 container_of(otg_sx, struct ssusb_mtk, otg_switch);
115 struct regulator *vbus = otg_sx->vbus;
118 /* vbus is optional */
122 dev_dbg(ssusb->dev, "%s: turn %s\n", __func__, is_on ? "on" : "off");
125 ret = regulator_enable(vbus);
127 dev_err(ssusb->dev, "vbus regulator enable failed\n");
131 regulator_disable(vbus);
138 * switch to host: -> MTU3_VBUS_OFF --> MTU3_ID_GROUND
139 * switch to device: -> MTU3_ID_FLOAT --> MTU3_VBUS_VALID
141 static void ssusb_set_mailbox(struct otg_switch_mtk *otg_sx,
142 enum mtu3_vbus_id_state status)
144 struct ssusb_mtk *ssusb =
145 container_of(otg_sx, struct ssusb_mtk, otg_switch);
146 struct mtu3 *mtu = ssusb->u3d;
148 dev_dbg(ssusb->dev, "mailbox state(%d)\n", status);
152 switch_port_to_host(ssusb);
153 ssusb_set_vbus(otg_sx, 1);
154 ssusb->is_host = true;
157 ssusb->is_host = false;
158 ssusb_set_vbus(otg_sx, 0);
159 switch_port_to_device(ssusb);
163 pm_relax(ssusb->dev);
165 case MTU3_VBUS_VALID:
166 /* avoid suspend when works as device */
167 pm_stay_awake(ssusb->dev);
171 dev_err(ssusb->dev, "invalid state\n");
175 static void ssusb_id_work(struct work_struct *work)
177 struct otg_switch_mtk *otg_sx =
178 container_of(work, struct otg_switch_mtk, id_work);
180 if (otg_sx->id_event)
181 ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND);
183 ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
186 static void ssusb_vbus_work(struct work_struct *work)
188 struct otg_switch_mtk *otg_sx =
189 container_of(work, struct otg_switch_mtk, vbus_work);
191 if (otg_sx->vbus_event)
192 ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
194 ssusb_set_mailbox(otg_sx, MTU3_VBUS_OFF);
198 * @ssusb_id_notifier is called in atomic context, but @ssusb_set_mailbox
199 * may sleep, so use work queue here
201 static int ssusb_id_notifier(struct notifier_block *nb,
202 unsigned long event, void *ptr)
204 struct otg_switch_mtk *otg_sx =
205 container_of(nb, struct otg_switch_mtk, id_nb);
207 otg_sx->id_event = event;
208 schedule_work(&otg_sx->id_work);
213 static int ssusb_vbus_notifier(struct notifier_block *nb,
214 unsigned long event, void *ptr)
216 struct otg_switch_mtk *otg_sx =
217 container_of(nb, struct otg_switch_mtk, vbus_nb);
219 otg_sx->vbus_event = event;
220 schedule_work(&otg_sx->vbus_work);
225 static int ssusb_extcon_register(struct otg_switch_mtk *otg_sx)
227 struct ssusb_mtk *ssusb =
228 container_of(otg_sx, struct ssusb_mtk, otg_switch);
229 struct extcon_dev *edev = otg_sx->edev;
232 /* extcon is optional */
236 otg_sx->vbus_nb.notifier_call = ssusb_vbus_notifier;
237 ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB,
240 dev_err(ssusb->dev, "failed to register notifier for USB\n");
242 otg_sx->id_nb.notifier_call = ssusb_id_notifier;
243 ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB_HOST,
246 dev_err(ssusb->dev, "failed to register notifier for USB-HOST\n");
248 dev_dbg(ssusb->dev, "EXTCON_USB: %d, EXTCON_USB_HOST: %d\n",
249 extcon_get_state(edev, EXTCON_USB),
250 extcon_get_state(edev, EXTCON_USB_HOST));
252 /* default as host, switch to device mode if needed */
253 if (extcon_get_state(edev, EXTCON_USB_HOST) == false)
254 ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
255 if (extcon_get_state(edev, EXTCON_USB) == true)
256 ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
262 * We provide an interface via debugfs to switch between host and device modes
263 * depending on user input.
264 * This is useful in special cases, such as uses TYPE-A receptacle but also
265 * wants to support dual-role mode.
267 static void ssusb_mode_manual_switch(struct ssusb_mtk *ssusb, int to_host)
269 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
272 ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_HOST);
273 ssusb_set_mailbox(otg_sx, MTU3_VBUS_OFF);
274 ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND);
276 ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_DEVICE);
277 ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
278 ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
282 static int ssusb_mode_show(struct seq_file *sf, void *unused)
284 struct ssusb_mtk *ssusb = sf->private;
286 seq_printf(sf, "current mode: %s(%s drd)\n(echo device/host)\n",
287 ssusb->is_host ? "host" : "device",
288 ssusb->otg_switch.manual_drd_enabled ? "manual" : "auto");
293 static int ssusb_mode_open(struct inode *inode, struct file *file)
295 return single_open(file, ssusb_mode_show, inode->i_private);
298 static ssize_t ssusb_mode_write(struct file *file,
299 const char __user *ubuf, size_t count, loff_t *ppos)
301 struct seq_file *sf = file->private_data;
302 struct ssusb_mtk *ssusb = sf->private;
305 if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
308 if (!strncmp(buf, "host", 4) && !ssusb->is_host) {
309 ssusb_mode_manual_switch(ssusb, 1);
310 } else if (!strncmp(buf, "device", 6) && ssusb->is_host) {
311 ssusb_mode_manual_switch(ssusb, 0);
313 dev_err(ssusb->dev, "wrong or duplicated setting\n");
320 static const struct file_operations ssusb_mode_fops = {
321 .open = ssusb_mode_open,
322 .write = ssusb_mode_write,
325 .release = single_release,
328 static int ssusb_vbus_show(struct seq_file *sf, void *unused)
330 struct ssusb_mtk *ssusb = sf->private;
331 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
333 seq_printf(sf, "vbus state: %s\n(echo on/off)\n",
334 regulator_is_enabled(otg_sx->vbus) ? "on" : "off");
339 static int ssusb_vbus_open(struct inode *inode, struct file *file)
341 return single_open(file, ssusb_vbus_show, inode->i_private);
344 static ssize_t ssusb_vbus_write(struct file *file,
345 const char __user *ubuf, size_t count, loff_t *ppos)
347 struct seq_file *sf = file->private_data;
348 struct ssusb_mtk *ssusb = sf->private;
349 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
353 if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
356 if (kstrtobool(buf, &enable)) {
357 dev_err(ssusb->dev, "wrong setting\n");
361 ssusb_set_vbus(otg_sx, enable);
366 static const struct file_operations ssusb_vbus_fops = {
367 .open = ssusb_vbus_open,
368 .write = ssusb_vbus_write,
371 .release = single_release,
374 static void ssusb_debugfs_init(struct ssusb_mtk *ssusb)
378 root = debugfs_create_dir(dev_name(ssusb->dev), usb_debug_root);
379 ssusb->dbgfs_root = root;
381 debugfs_create_file("mode", 0644, root, ssusb, &ssusb_mode_fops);
382 debugfs_create_file("vbus", 0644, root, ssusb, &ssusb_vbus_fops);
385 static void ssusb_debugfs_exit(struct ssusb_mtk *ssusb)
387 debugfs_remove_recursive(ssusb->dbgfs_root);
390 void ssusb_set_force_mode(struct ssusb_mtk *ssusb,
391 enum mtu3_dr_force_mode mode)
395 value = mtu3_readl(ssusb->ippc_base, SSUSB_U2_CTRL(0));
397 case MTU3_DR_FORCE_DEVICE:
398 value |= SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG;
400 case MTU3_DR_FORCE_HOST:
401 value |= SSUSB_U2_PORT_FORCE_IDDIG;
402 value &= ~SSUSB_U2_PORT_RG_IDDIG;
404 case MTU3_DR_FORCE_NONE:
405 value &= ~(SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG);
410 mtu3_writel(ssusb->ippc_base, SSUSB_U2_CTRL(0), value);
413 int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)
415 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
417 INIT_WORK(&otg_sx->id_work, ssusb_id_work);
418 INIT_WORK(&otg_sx->vbus_work, ssusb_vbus_work);
420 if (otg_sx->manual_drd_enabled)
421 ssusb_debugfs_init(ssusb);
423 ssusb_extcon_register(otg_sx);
428 void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb)
430 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
432 if (otg_sx->manual_drd_enabled)
433 ssusb_debugfs_exit(ssusb);
435 cancel_work_sync(&otg_sx->id_work);
436 cancel_work_sync(&otg_sx->vbus_work);