2 * mtu3_dr.c - dual role switch and host glue layer
4 * Copyright (C) 2016 MediaTek Inc.
6 * Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
8 * This software is licensed under the terms of the GNU General Public
9 * License version 2, as published by the Free Software Foundation, and
10 * may be copied, distributed, and modified under those terms.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
19 #include <linux/debugfs.h>
20 #include <linux/irq.h>
21 #include <linux/kernel.h>
22 #include <linux/of_device.h>
23 #include <linux/pinctrl/consumer.h>
24 #include <linux/seq_file.h>
25 #include <linux/uaccess.h>
33 enum mtu3_vbus_id_state {
40 static void toggle_opstate(struct ssusb_mtk *ssusb)
42 mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION);
43 mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN);
46 /* only port0 supports dual-role mode */
47 static int ssusb_port0_switch(struct ssusb_mtk *ssusb,
48 int version, bool tohost)
50 void __iomem *ibase = ssusb->ippc_base;
53 dev_dbg(ssusb->dev, "%s (switch u%d port0 to %s)\n", __func__,
54 version, tohost ? "host" : "device");
56 if (version == USB2_PORT) {
57 /* 1. power off and disable u2 port0 */
58 value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
59 value |= SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS;
60 mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
62 /* 2. power on, enable u2 port0 and select its mode */
63 value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
64 value &= ~(SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS);
65 value = tohost ? (value | SSUSB_U2_PORT_HOST_SEL) :
66 (value & (~SSUSB_U2_PORT_HOST_SEL));
67 mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
69 /* 1. power off and disable u3 port0 */
70 value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
71 value |= SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS;
72 mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
74 /* 2. power on, enable u3 port0 and select its mode */
75 value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
76 value &= ~(SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS);
77 value = tohost ? (value | SSUSB_U3_PORT_HOST_SEL) :
78 (value & (~SSUSB_U3_PORT_HOST_SEL));
79 mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
85 static void switch_port_to_host(struct ssusb_mtk *ssusb)
89 dev_dbg(ssusb->dev, "%s\n", __func__);
91 ssusb_port0_switch(ssusb, USB2_PORT, true);
93 if (ssusb->otg_switch.is_u3_drd) {
94 ssusb_port0_switch(ssusb, USB3_PORT, true);
95 check_clk = SSUSB_U3_MAC_RST_B_STS;
98 ssusb_check_clocks(ssusb, check_clk);
100 /* after all clocks are stable */
101 toggle_opstate(ssusb);
104 static void switch_port_to_device(struct ssusb_mtk *ssusb)
108 dev_dbg(ssusb->dev, "%s\n", __func__);
110 ssusb_port0_switch(ssusb, USB2_PORT, false);
112 if (ssusb->otg_switch.is_u3_drd) {
113 ssusb_port0_switch(ssusb, USB3_PORT, false);
114 check_clk = SSUSB_U3_MAC_RST_B_STS;
117 ssusb_check_clocks(ssusb, check_clk);
120 int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on)
122 struct ssusb_mtk *ssusb =
123 container_of(otg_sx, struct ssusb_mtk, otg_switch);
124 struct regulator *vbus = otg_sx->vbus;
127 /* vbus is optional */
131 dev_dbg(ssusb->dev, "%s: turn %s\n", __func__, is_on ? "on" : "off");
134 ret = regulator_enable(vbus);
136 dev_err(ssusb->dev, "vbus regulator enable failed\n");
140 regulator_disable(vbus);
147 * switch to host: -> MTU3_VBUS_OFF --> MTU3_ID_GROUND
148 * switch to device: -> MTU3_ID_FLOAT --> MTU3_VBUS_VALID
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 state(%d)\n", status);
161 switch_port_to_host(ssusb);
162 ssusb_set_vbus(otg_sx, 1);
163 ssusb->is_host = true;
166 ssusb->is_host = false;
167 ssusb_set_vbus(otg_sx, 0);
168 switch_port_to_device(ssusb);
172 pm_relax(ssusb->dev);
174 case MTU3_VBUS_VALID:
175 /* avoid suspend when works as device */
176 pm_stay_awake(ssusb->dev);
180 dev_err(ssusb->dev, "invalid state\n");
184 static int ssusb_id_notifier(struct notifier_block *nb,
185 unsigned long event, void *ptr)
187 struct otg_switch_mtk *otg_sx =
188 container_of(nb, struct otg_switch_mtk, id_nb);
191 ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND);
193 ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
198 static int ssusb_vbus_notifier(struct notifier_block *nb,
199 unsigned long event, void *ptr)
201 struct otg_switch_mtk *otg_sx =
202 container_of(nb, struct otg_switch_mtk, vbus_nb);
205 ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
207 ssusb_set_mailbox(otg_sx, MTU3_VBUS_OFF);
212 static int ssusb_extcon_register(struct otg_switch_mtk *otg_sx)
214 struct ssusb_mtk *ssusb =
215 container_of(otg_sx, struct ssusb_mtk, otg_switch);
216 struct extcon_dev *edev = otg_sx->edev;
219 /* extcon is optional */
223 otg_sx->vbus_nb.notifier_call = ssusb_vbus_notifier;
224 ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB,
227 dev_err(ssusb->dev, "failed to register notifier for USB\n");
229 otg_sx->id_nb.notifier_call = ssusb_id_notifier;
230 ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB_HOST,
233 dev_err(ssusb->dev, "failed to register notifier for USB-HOST\n");
235 dev_dbg(ssusb->dev, "EXTCON_USB: %d, EXTCON_USB_HOST: %d\n",
236 extcon_get_state(edev, EXTCON_USB),
237 extcon_get_state(edev, EXTCON_USB_HOST));
239 /* default as host, switch to device mode if needed */
240 if (extcon_get_state(edev, EXTCON_USB_HOST) == false)
241 ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
242 if (extcon_get_state(edev, EXTCON_USB) == true)
243 ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
248 static void extcon_register_dwork(struct work_struct *work)
250 struct delayed_work *dwork = to_delayed_work(work);
251 struct otg_switch_mtk *otg_sx =
252 container_of(dwork, struct otg_switch_mtk, extcon_reg_dwork);
254 ssusb_extcon_register(otg_sx);
258 * We provide an interface via debugfs to switch between host and device modes
259 * depending on user input.
260 * This is useful in special cases, such as uses TYPE-A receptacle but also
261 * wants to support dual-role mode.
262 * It generates cable state changes by pulling up/down IDPIN and
263 * notifies driver to switch mode by "extcon-usb-gpio".
264 * NOTE: when use MICRO receptacle, should not enable this interface.
266 static void ssusb_mode_manual_switch(struct ssusb_mtk *ssusb, int to_host)
268 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
271 pinctrl_select_state(otg_sx->id_pinctrl, otg_sx->id_ground);
273 pinctrl_select_state(otg_sx->id_pinctrl, otg_sx->id_float);
277 static int ssusb_mode_show(struct seq_file *sf, void *unused)
279 struct ssusb_mtk *ssusb = sf->private;
281 seq_printf(sf, "current mode: %s(%s drd)\n(echo device/host)\n",
282 ssusb->is_host ? "host" : "device",
283 ssusb->otg_switch.manual_drd_enabled ? "manual" : "auto");
288 static int ssusb_mode_open(struct inode *inode, struct file *file)
290 return single_open(file, ssusb_mode_show, inode->i_private);
293 static ssize_t ssusb_mode_write(struct file *file,
294 const char __user *ubuf, size_t count, loff_t *ppos)
296 struct seq_file *sf = file->private_data;
297 struct ssusb_mtk *ssusb = sf->private;
300 if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
303 if (!strncmp(buf, "host", 4) && !ssusb->is_host) {
304 ssusb_mode_manual_switch(ssusb, 1);
305 } else if (!strncmp(buf, "device", 6) && ssusb->is_host) {
306 ssusb_mode_manual_switch(ssusb, 0);
308 dev_err(ssusb->dev, "wrong or duplicated setting\n");
315 static const struct file_operations ssusb_mode_fops = {
316 .open = ssusb_mode_open,
317 .write = ssusb_mode_write,
320 .release = single_release,
323 static int ssusb_vbus_show(struct seq_file *sf, void *unused)
325 struct ssusb_mtk *ssusb = sf->private;
326 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
328 seq_printf(sf, "vbus state: %s\n(echo on/off)\n",
329 regulator_is_enabled(otg_sx->vbus) ? "on" : "off");
334 static int ssusb_vbus_open(struct inode *inode, struct file *file)
336 return single_open(file, ssusb_vbus_show, inode->i_private);
339 static ssize_t ssusb_vbus_write(struct file *file,
340 const char __user *ubuf, size_t count, loff_t *ppos)
342 struct seq_file *sf = file->private_data;
343 struct ssusb_mtk *ssusb = sf->private;
344 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
348 if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
351 if (kstrtobool(buf, &enable)) {
352 dev_err(ssusb->dev, "wrong setting\n");
356 ssusb_set_vbus(otg_sx, enable);
361 static const struct file_operations ssusb_vbus_fops = {
362 .open = ssusb_vbus_open,
363 .write = ssusb_vbus_write,
366 .release = single_release,
369 static void ssusb_debugfs_init(struct ssusb_mtk *ssusb)
373 root = debugfs_create_dir(dev_name(ssusb->dev), usb_debug_root);
375 dev_err(ssusb->dev, "create debugfs root failed\n");
378 ssusb->dbgfs_root = root;
380 debugfs_create_file("mode", 0644, root, ssusb, &ssusb_mode_fops);
381 debugfs_create_file("vbus", 0644, root, ssusb, &ssusb_vbus_fops);
384 static void ssusb_debugfs_exit(struct ssusb_mtk *ssusb)
386 debugfs_remove_recursive(ssusb->dbgfs_root);
389 int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)
391 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
393 INIT_DELAYED_WORK(&otg_sx->extcon_reg_dwork, extcon_register_dwork);
395 if (otg_sx->manual_drd_enabled)
396 ssusb_debugfs_init(ssusb);
398 /* It is enough to delay 1s for waiting for host initialization */
399 schedule_delayed_work(&otg_sx->extcon_reg_dwork, HZ);
404 void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb)
406 struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
408 cancel_delayed_work(&otg_sx->extcon_reg_dwork);
410 if (otg_sx->manual_drd_enabled)
411 ssusb_debugfs_exit(ssusb);