[mirror_ubuntu-jammy-kernel.git] / drivers / usb / mtu3 / mtu3_dr.c

// SPDX-License-Identifier: GPL-2.0
/*
 * mtu3_dr.c - dual role switch and host glue layer
 *
 * Copyright (C) 2016 MediaTek Inc.
 *
 * Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/debugfs.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/of_device.h>
#include <linux/pinctrl/consumer.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>

#include "mtu3.h"
#include "mtu3_dr.h"

#define USB2_PORT 2
#define USB3_PORT 3

enum mtu3_vbus_id_state {
	MTU3_ID_FLOAT = 1,
	MTU3_ID_GROUND,
	MTU3_VBUS_OFF,
	MTU3_VBUS_VALID,
};

static void toggle_opstate(struct ssusb_mtk *ssusb)
{
	if (!ssusb->otg_switch.is_u3_drd) {
		mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION);
		mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN);
	}
}

/* only port0 supports dual-role mode */
static int ssusb_port0_switch(struct ssusb_mtk *ssusb,
	int version, bool tohost)
{
	void __iomem *ibase = ssusb->ippc_base;
	u32 value;

	dev_dbg(ssusb->dev, "%s (switch u%d port0 to %s)\n", __func__,
		version, tohost ? "host" : "device");

	if (version == USB2_PORT) {
		/* 1. power off and disable u2 port0 */
		value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
		value |= SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS;
		mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);

		/* 2. power on, enable u2 port0 and select its mode */
		value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
		value &= ~(SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS);
		value = tohost ? (value | SSUSB_U2_PORT_HOST_SEL) :
			(value & (~SSUSB_U2_PORT_HOST_SEL));
		mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
	} else {
		/* 1. power off and disable u3 port0 */
		value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
		value |= SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS;
		mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);

		/* 2. power on, enable u3 port0 and select its mode */
		value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
		value &= ~(SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS);
		value = tohost ? (value | SSUSB_U3_PORT_HOST_SEL) :
			(value & (~SSUSB_U3_PORT_HOST_SEL));
		mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
	}

	return 0;
}

static void switch_port_to_host(struct ssusb_mtk *ssusb)
{
	u32 check_clk = 0;

	dev_dbg(ssusb->dev, "%s\n", __func__);

	ssusb_port0_switch(ssusb, USB2_PORT, true);

	if (ssusb->otg_switch.is_u3_drd) {
		ssusb_port0_switch(ssusb, USB3_PORT, true);
		check_clk = SSUSB_U3_MAC_RST_B_STS;
	}

	ssusb_check_clocks(ssusb, check_clk);

	/* after all clocks are stable */
	toggle_opstate(ssusb);
}

static void switch_port_to_device(struct ssusb_mtk *ssusb)
{
	u32 check_clk = 0;

	dev_dbg(ssusb->dev, "%s\n", __func__);

	ssusb_port0_switch(ssusb, USB2_PORT, false);

	if (ssusb->otg_switch.is_u3_drd) {
		ssusb_port0_switch(ssusb, USB3_PORT, false);
		check_clk = SSUSB_U3_MAC_RST_B_STS;
	}

	ssusb_check_clocks(ssusb, check_clk);
}

int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on)
{
	struct ssusb_mtk *ssusb =
		container_of(otg_sx, struct ssusb_mtk, otg_switch);
	struct regulator *vbus = otg_sx->vbus;
	int ret;

	/* vbus is optional */
	if (!vbus)
		return 0;

	dev_dbg(ssusb->dev, "%s: turn %s\n", __func__, is_on ? "on" : "off");

	if (is_on) {
		ret = regulator_enable(vbus);
		if (ret) {
			dev_err(ssusb->dev, "vbus regulator enable failed\n");
			return ret;
		}
	} else {
		regulator_disable(vbus);
	}

	return 0;
}

/*
 * switch to host: -> MTU3_VBUS_OFF --> MTU3_ID_GROUND
 * switch to device: -> MTU3_ID_FLOAT --> MTU3_VBUS_VALID
 */
static void ssusb_set_mailbox(struct otg_switch_mtk *otg_sx,
	enum mtu3_vbus_id_state status)
{
	struct ssusb_mtk *ssusb =
		container_of(otg_sx, struct ssusb_mtk, otg_switch);
	struct mtu3 *mtu = ssusb->u3d;

	dev_dbg(ssusb->dev, "mailbox state(%d)\n", status);

	switch (status) {
	case MTU3_ID_GROUND:
		switch_port_to_host(ssusb);
		ssusb_set_vbus(otg_sx, 1);
		ssusb->is_host = true;
		break;
	case MTU3_ID_FLOAT:
		ssusb->is_host = false;
		ssusb_set_vbus(otg_sx, 0);
		switch_port_to_device(ssusb);
		break;
	case MTU3_VBUS_OFF:
		mtu3_stop(mtu);
		pm_relax(ssusb->dev);
		break;
	case MTU3_VBUS_VALID:
		/* avoid suspend when works as device */
		pm_stay_awake(ssusb->dev);
		mtu3_start(mtu);
		break;
	default:
		dev_err(ssusb->dev, "invalid state\n");
	}
}

static int ssusb_id_notifier(struct notifier_block *nb,
	unsigned long event, void *ptr)
{
	struct otg_switch_mtk *otg_sx =
		container_of(nb, struct otg_switch_mtk, id_nb);

	if (event)
		ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND);
	else
		ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);

	return NOTIFY_DONE;
}

static int ssusb_vbus_notifier(struct notifier_block *nb,
	unsigned long event, void *ptr)
{
	struct otg_switch_mtk *otg_sx =
		container_of(nb, struct otg_switch_mtk, vbus_nb);

	if (event)
		ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
	else
		ssusb_set_mailbox(otg_sx, MTU3_VBUS_OFF);

	return NOTIFY_DONE;
}

static int ssusb_extcon_register(struct otg_switch_mtk *otg_sx)
{
	struct ssusb_mtk *ssusb =
		container_of(otg_sx, struct ssusb_mtk, otg_switch);
	struct extcon_dev *edev = otg_sx->edev;
	int ret;

	/* extcon is optional */
	if (!edev)
		return 0;

	otg_sx->vbus_nb.notifier_call = ssusb_vbus_notifier;
	ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB,
					&otg_sx->vbus_nb);
	if (ret < 0)
		dev_err(ssusb->dev, "failed to register notifier for USB\n");

	otg_sx->id_nb.notifier_call = ssusb_id_notifier;
	ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB_HOST,
					&otg_sx->id_nb);
	if (ret < 0)
		dev_err(ssusb->dev, "failed to register notifier for USB-HOST\n");

	dev_dbg(ssusb->dev, "EXTCON_USB: %d, EXTCON_USB_HOST: %d\n",
		extcon_get_state(edev, EXTCON_USB),
		extcon_get_state(edev, EXTCON_USB_HOST));

	/* default as host, switch to device mode if needed */
	if (extcon_get_state(edev, EXTCON_USB_HOST) == false)
		ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
	if (extcon_get_state(edev, EXTCON_USB) == true)
		ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);

	return 0;
}

static void extcon_register_dwork(struct work_struct *work)
{
	struct delayed_work *dwork = to_delayed_work(work);
	struct otg_switch_mtk *otg_sx =
	    container_of(dwork, struct otg_switch_mtk, extcon_reg_dwork);

	ssusb_extcon_register(otg_sx);
}

/*
 * We provide an interface via debugfs to switch between host and device modes
 * depending on user input.
 * This is useful in special cases, such as uses TYPE-A receptacle but also
 * wants to support dual-role mode.
 */
static void ssusb_mode_manual_switch(struct ssusb_mtk *ssusb, int to_host)
{
	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;

	if (to_host) {
		ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_HOST);
		ssusb_set_mailbox(otg_sx, MTU3_VBUS_OFF);
		ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND);
	} else {
		ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_DEVICE);
		ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
		ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
	}
}

static int ssusb_mode_show(struct seq_file *sf, void *unused)
{
	struct ssusb_mtk *ssusb = sf->private;

	seq_printf(sf, "current mode: %s(%s drd)\n(echo device/host)\n",
		ssusb->is_host ? "host" : "device",
		ssusb->otg_switch.manual_drd_enabled ? "manual" : "auto");

	return 0;
}

static int ssusb_mode_open(struct inode *inode, struct file *file)
{
	return single_open(file, ssusb_mode_show, inode->i_private);
}

static ssize_t ssusb_mode_write(struct file *file,
	const char __user *ubuf, size_t count, loff_t *ppos)
{
	struct seq_file *sf = file->private_data;
	struct ssusb_mtk *ssusb = sf->private;
	char buf[16];

	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
		return -EFAULT;

	if (!strncmp(buf, "host", 4) && !ssusb->is_host) {
		ssusb_mode_manual_switch(ssusb, 1);
	} else if (!strncmp(buf, "device", 6) && ssusb->is_host) {
		ssusb_mode_manual_switch(ssusb, 0);
	} else {
		dev_err(ssusb->dev, "wrong or duplicated setting\n");
		return -EINVAL;
	}

	return count;
}

static const struct file_operations ssusb_mode_fops = {
	.open = ssusb_mode_open,
	.write = ssusb_mode_write,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
};

static int ssusb_vbus_show(struct seq_file *sf, void *unused)
{
	struct ssusb_mtk *ssusb = sf->private;
	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;

	seq_printf(sf, "vbus state: %s\n(echo on/off)\n",
		regulator_is_enabled(otg_sx->vbus) ? "on" : "off");

	return 0;
}

static int ssusb_vbus_open(struct inode *inode, struct file *file)
{
	return single_open(file, ssusb_vbus_show, inode->i_private);
}

static ssize_t ssusb_vbus_write(struct file *file,
	const char __user *ubuf, size_t count, loff_t *ppos)
{
	struct seq_file *sf = file->private_data;
	struct ssusb_mtk *ssusb = sf->private;
	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
	char buf[16];
	bool enable;

	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
		return -EFAULT;

	if (kstrtobool(buf, &enable)) {
		dev_err(ssusb->dev, "wrong setting\n");
		return -EINVAL;
	}

	ssusb_set_vbus(otg_sx, enable);

	return count;
}

static const struct file_operations ssusb_vbus_fops = {
	.open = ssusb_vbus_open,
	.write = ssusb_vbus_write,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
};

static void ssusb_debugfs_init(struct ssusb_mtk *ssusb)
{
	struct dentry *root;

	root = debugfs_create_dir(dev_name(ssusb->dev), usb_debug_root);
	if (!root) {
		dev_err(ssusb->dev, "create debugfs root failed\n");
		return;
	}
	ssusb->dbgfs_root = root;

	debugfs_create_file("mode", 0644, root, ssusb, &ssusb_mode_fops);
	debugfs_create_file("vbus", 0644, root, ssusb, &ssusb_vbus_fops);
}

static void ssusb_debugfs_exit(struct ssusb_mtk *ssusb)
{
	debugfs_remove_recursive(ssusb->dbgfs_root);
}

void ssusb_set_force_mode(struct ssusb_mtk *ssusb,
			  enum mtu3_dr_force_mode mode)
{
	u32 value;

	value = mtu3_readl(ssusb->ippc_base, SSUSB_U2_CTRL(0));
	switch (mode) {
	case MTU3_DR_FORCE_DEVICE:
		value |= SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG;
		break;
	case MTU3_DR_FORCE_HOST:
		value |= SSUSB_U2_PORT_FORCE_IDDIG;
		value &= ~SSUSB_U2_PORT_RG_IDDIG;
		break;
	case MTU3_DR_FORCE_NONE:
		value &= ~(SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG);
		break;
	default:
		return;
	}
	mtu3_writel(ssusb->ippc_base, SSUSB_U2_CTRL(0), value);
}

int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)
{
	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;

	if (otg_sx->manual_drd_enabled) {
		ssusb_debugfs_init(ssusb);
	} else {
		INIT_DELAYED_WORK(&otg_sx->extcon_reg_dwork,
				  extcon_register_dwork);

		/*
		 * It is enough to delay 1s for waiting for
		 * host initialization
		 */
		schedule_delayed_work(&otg_sx->extcon_reg_dwork, HZ);
	}

	return 0;
}

void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb)
{
	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;

	if (otg_sx->manual_drd_enabled)
		ssusb_debugfs_exit(ssusb);
	else
		cancel_delayed_work(&otg_sx->extcon_reg_dwork);
}
Commit	Line	Data
5fd54ace	1	// SPDX-License-Identifier: GPL-2.0
d0ed062a CY	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	* This software is licensed under the terms of the GNU General Public
	10	* License version 2, as published by the Free Software Foundation, and
	11	* may be copied, distributed, and modified under those terms.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	*/
	19
	20	#include <linux/debugfs.h>
	21	#include <linux/irq.h>
	22	#include <linux/kernel.h>
	23	#include <linux/of_device.h>
	24	#include <linux/pinctrl/consumer.h>
	25	#include <linux/seq_file.h>
	26	#include <linux/uaccess.h>
	27
	28	#include "mtu3.h"
	29	#include "mtu3_dr.h"
	30
	31	#define USB2_PORT 2
	32	#define USB3_PORT 3
	33
	34	enum mtu3_vbus_id_state {
	35	MTU3_ID_FLOAT = 1,
	36	MTU3_ID_GROUND,
	37	MTU3_VBUS_OFF,
	38	MTU3_VBUS_VALID,
	39	};
	40
	41	static void toggle_opstate(struct ssusb_mtk *ssusb)
	42	{
	43	if (!ssusb->otg_switch.is_u3_drd) {
	44	mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION);
	45	mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN);
	46	}
	47	}
	48
	49	/* only port0 supports dual-role mode */
	50	static int ssusb_port0_switch(struct ssusb_mtk *ssusb,
	51	int version, bool tohost)
	52	{
	53	void __iomem *ibase = ssusb->ippc_base;
	54	u32 value;
	55
	56	dev_dbg(ssusb->dev, "%s (switch u%d port0 to %s)\n", __func__,
	57	version, tohost ? "host" : "device");
	58
	59	if (version == USB2_PORT) {
	60	/* 1. power off and disable u2 port0 */
	61	value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
	62	value \|= SSUSB_U2_PORT_PDN \| SSUSB_U2_PORT_DIS;
	63	mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
	64
	65	/* 2. power on, enable u2 port0 and select its mode */
66	value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
67	value &= ~(SSUSB_U2_PORT_PDN \| SSUSB_U2_PORT_DIS);
68	value = tohost ? (value \| SSUSB_U2_PORT_HOST_SEL) :
69	(value & (~SSUSB_U2_PORT_HOST_SEL));
70	mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
71	} else {
72	/* 1. power off and disable u3 port0 */
73	value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
74	value \|= SSUSB_U3_PORT_PDN \| SSUSB_U3_PORT_DIS;
75	mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
76
77	/* 2. power on, enable u3 port0 and select its mode */
78	value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
79	value &= ~(SSUSB_U3_PORT_PDN \| SSUSB_U3_PORT_DIS);
80	value = tohost ? (value \| SSUSB_U3_PORT_HOST_SEL) :
81	(value & (~SSUSB_U3_PORT_HOST_SEL));
82	mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
83	}
84
85	return 0;
86	}
87
88	static void switch_port_to_host(struct ssusb_mtk *ssusb)
89	{
90	u32 check_clk = 0;
91
92	dev_dbg(ssusb->dev, "%s\n", __func__);
93
94	ssusb_port0_switch(ssusb, USB2_PORT, true);
95
96	if (ssusb->otg_switch.is_u3_drd) {
97	ssusb_port0_switch(ssusb, USB3_PORT, true);
98	check_clk = SSUSB_U3_MAC_RST_B_STS;
99	}
100
101	ssusb_check_clocks(ssusb, check_clk);
102
103	/* after all clocks are stable */
104	toggle_opstate(ssusb);
105	}
106
107	static void switch_port_to_device(struct ssusb_mtk *ssusb)
108	{
109	u32 check_clk = 0;
110
111	dev_dbg(ssusb->dev, "%s\n", __func__);
112
113	ssusb_port0_switch(ssusb, USB2_PORT, false);
114
115	if (ssusb->otg_switch.is_u3_drd) {
116	ssusb_port0_switch(ssusb, USB3_PORT, false);
117	check_clk = SSUSB_U3_MAC_RST_B_STS;
118	}
119
120	ssusb_check_clocks(ssusb, check_clk);
121	}
122
123	int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on)
124	{
125	struct ssusb_mtk *ssusb =
126	container_of(otg_sx, struct ssusb_mtk, otg_switch);
127	struct regulator *vbus = otg_sx->vbus;
128	int ret;
129
130	/* vbus is optional */
131	if (!vbus)
132	return 0;
133
134	dev_dbg(ssusb->dev, "%s: turn %s\n", __func__, is_on ? "on" : "off");
135
136	if (is_on) {
137	ret = regulator_enable(vbus);
138	if (ret) {
139	dev_err(ssusb->dev, "vbus regulator enable failed\n");
140	return ret;
141	}
142	} else {
143	regulator_disable(vbus);
144	}
145
146	return 0;
147	}
148
149	/*
150	* switch to host: -> MTU3_VBUS_OFF --> MTU3_ID_GROUND
151	* switch to device: -> MTU3_ID_FLOAT --> MTU3_VBUS_VALID
152	*/
153	static void ssusb_set_mailbox(struct otg_switch_mtk *otg_sx,
154	enum mtu3_vbus_id_state status)
155	{
156	struct ssusb_mtk *ssusb =
157	container_of(otg_sx, struct ssusb_mtk, otg_switch);
158	struct mtu3 *mtu = ssusb->u3d;
159
160	dev_dbg(ssusb->dev, "mailbox state(%d)\n", status);
161
162	switch (status) {
163	case MTU3_ID_GROUND:
164	switch_port_to_host(ssusb);
165	ssusb_set_vbus(otg_sx, 1);
166	ssusb->is_host = true;
167	break;
168	case MTU3_ID_FLOAT:
169	ssusb->is_host = false;
170	ssusb_set_vbus(otg_sx, 0);
171	switch_port_to_device(ssusb);
172	break;
173	case MTU3_VBUS_OFF:
174	mtu3_stop(mtu);
175	pm_relax(ssusb->dev);
176	break;
177	case MTU3_VBUS_VALID:
178	/* avoid suspend when works as device */
179	pm_stay_awake(ssusb->dev);
180	mtu3_start(mtu);
181	break;
182	default:
183	dev_err(ssusb->dev, "invalid state\n");
184	}
185	}
186
187	static int ssusb_id_notifier(struct notifier_block *nb,
188	unsigned long event, void *ptr)
189	{
190	struct otg_switch_mtk *otg_sx =
191	container_of(nb, struct otg_switch_mtk, id_nb);
192
193	if (event)
194	ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND);
195	else
196	ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
197
198	return NOTIFY_DONE;
199	}
200
201	static int ssusb_vbus_notifier(struct notifier_block *nb,
202	unsigned long event, void *ptr)
203	{
204	struct otg_switch_mtk *otg_sx =
205	container_of(nb, struct otg_switch_mtk, vbus_nb);
206
207	if (event)
208	ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
209	else
210	ssusb_set_mailbox(otg_sx, MTU3_VBUS_OFF);
211
212	return NOTIFY_DONE;
213	}
214
215	static int ssusb_extcon_register(struct otg_switch_mtk *otg_sx)
216	{
217	struct ssusb_mtk *ssusb =
218	container_of(otg_sx, struct ssusb_mtk, otg_switch);
219	struct extcon_dev *edev = otg_sx->edev;
220	int ret;
221
222	/* extcon is optional */
223	if (!edev)
224	return 0;
225
226	otg_sx->vbus_nb.notifier_call = ssusb_vbus_notifier;
a2cfed43	227	ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB,
d0ed062a CY	228	&otg_sx->vbus_nb);
	229	if (ret < 0)
	230	dev_err(ssusb->dev, "failed to register notifier for USB\n");
	231
	232	otg_sx->id_nb.notifier_call = ssusb_id_notifier;
a2cfed43	233	ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB_HOST,
d0ed062a CY	234	&otg_sx->id_nb);
	235	if (ret < 0)
	236	dev_err(ssusb->dev, "failed to register notifier for USB-HOST\n");
	237
	238	dev_dbg(ssusb->dev, "EXTCON_USB: %d, EXTCON_USB_HOST: %d\n",
a2cfed43 CC	239	extcon_get_state(edev, EXTCON_USB),
a2cfed43 CC	240	extcon_get_state(edev, EXTCON_USB_HOST));
d0ed062a CY	241
d0ed062a CY	242	/* default as host, switch to device mode if needed */
a2cfed43	243	if (extcon_get_state(edev, EXTCON_USB_HOST) == false)
d0ed062a	244	ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
a2cfed43	245	if (extcon_get_state(edev, EXTCON_USB) == true)
d0ed062a CY	246	ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
	247
	248	return 0;
	249	}
	250
	251	static void extcon_register_dwork(struct work_struct *work)
	252	{
	253	struct delayed_work *dwork = to_delayed_work(work);
	254	struct otg_switch_mtk *otg_sx =
	255	container_of(dwork, struct otg_switch_mtk, extcon_reg_dwork);
	256
	257	ssusb_extcon_register(otg_sx);
	258	}
	259
	260	/*
	261	* We provide an interface via debugfs to switch between host and device modes
	262	* depending on user input.
	263	* This is useful in special cases, such as uses TYPE-A receptacle but also
	264	* wants to support dual-role mode.
d0ed062a CY	265	*/
	266	static void ssusb_mode_manual_switch(struct ssusb_mtk *ssusb, int to_host)
	267	{
	268	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
	269
c776f2c3 CY	270	if (to_host) {
	271	ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_HOST);
	272	ssusb_set_mailbox(otg_sx, MTU3_VBUS_OFF);
	273	ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND);
	274	} else {
	275	ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_DEVICE);
	276	ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
	277	ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
	278	}
d0ed062a CY	279	}
d0ed062a CY	280
d0ed062a CY	281	static int ssusb_mode_show(struct seq_file sf, void unused)
	282	{
	283	struct ssusb_mtk *ssusb = sf->private;
	284
	285	seq_printf(sf, "current mode: %s(%s drd)\n(echo device/host)\n",
	286	ssusb->is_host ? "host" : "device",
	287	ssusb->otg_switch.manual_drd_enabled ? "manual" : "auto");
	288
	289	return 0;
	290	}
	291
	292	static int ssusb_mode_open(struct inode inode, struct file file)
	293	{
	294	return single_open(file, ssusb_mode_show, inode->i_private);
	295	}
	296
	297	static ssize_t ssusb_mode_write(struct file *file,
	298	const char __user ubuf, size_t count, loff_t ppos)
	299	{
	300	struct seq_file *sf = file->private_data;
	301	struct ssusb_mtk *ssusb = sf->private;
	302	char buf[16];
	303
	304	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
	305	return -EFAULT;
	306
	307	if (!strncmp(buf, "host", 4) && !ssusb->is_host) {
	308	ssusb_mode_manual_switch(ssusb, 1);
	309	} else if (!strncmp(buf, "device", 6) && ssusb->is_host) {
	310	ssusb_mode_manual_switch(ssusb, 0);
	311	} else {
	312	dev_err(ssusb->dev, "wrong or duplicated setting\n");
	313	return -EINVAL;
	314	}
	315
	316	return count;
	317	}
	318
	319	static const struct file_operations ssusb_mode_fops = {
	320	.open = ssusb_mode_open,
	321	.write = ssusb_mode_write,
	322	.read = seq_read,
	323	.llseek = seq_lseek,
	324	.release = single_release,
	325	};
	326
e97d2a39 CY	327	static int ssusb_vbus_show(struct seq_file sf, void unused)
	328	{
	329	struct ssusb_mtk *ssusb = sf->private;
	330	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
	331
	332	seq_printf(sf, "vbus state: %s\n(echo on/off)\n",
	333	regulator_is_enabled(otg_sx->vbus) ? "on" : "off");
	334
	335	return 0;
	336	}
	337
	338	static int ssusb_vbus_open(struct inode inode, struct file file)
	339	{
	340	return single_open(file, ssusb_vbus_show, inode->i_private);
	341	}
	342
	343	static ssize_t ssusb_vbus_write(struct file *file,
	344	const char __user ubuf, size_t count, loff_t ppos)
	345	{
	346	struct seq_file *sf = file->private_data;
	347	struct ssusb_mtk *ssusb = sf->private;
	348	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
	349	char buf[16];
	350	bool enable;
	351
	352	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
	353	return -EFAULT;
	354
	355	if (kstrtobool(buf, &enable)) {
	356	dev_err(ssusb->dev, "wrong setting\n");
	357	return -EINVAL;
	358	}
	359
	360	ssusb_set_vbus(otg_sx, enable);
	361
	362	return count;
	363	}
	364
	365	static const struct file_operations ssusb_vbus_fops = {
	366	.open = ssusb_vbus_open,
	367	.write = ssusb_vbus_write,
	368	.read = seq_read,
	369	.llseek = seq_lseek,
	370	.release = single_release,
	371	};
	372
d0ed062a CY	373	static void ssusb_debugfs_init(struct ssusb_mtk *ssusb)
	374	{
	375	struct dentry *root;
d0ed062a CY	376
d0ed062a CY	377	root = debugfs_create_dir(dev_name(ssusb->dev), usb_debug_root);
e97d2a39 CY	378	if (!root) {
e97d2a39 CY	379	dev_err(ssusb->dev, "create debugfs root failed\n");
d0ed062a CY	380	return;
	381	}
	382	ssusb->dbgfs_root = root;
	383
e97d2a39 CY	384	debugfs_create_file("mode", 0644, root, ssusb, &ssusb_mode_fops);
e97d2a39 CY	385	debugfs_create_file("vbus", 0644, root, ssusb, &ssusb_vbus_fops);
d0ed062a CY	386	}
	387
	388	static void ssusb_debugfs_exit(struct ssusb_mtk *ssusb)
	389	{
	390	debugfs_remove_recursive(ssusb->dbgfs_root);
	391	}
	392
c776f2c3 CY	393	void ssusb_set_force_mode(struct ssusb_mtk *ssusb,
	394	enum mtu3_dr_force_mode mode)
	395	{
	396	u32 value;
	397
	398	value = mtu3_readl(ssusb->ippc_base, SSUSB_U2_CTRL(0));
	399	switch (mode) {
	400	case MTU3_DR_FORCE_DEVICE:
	401	value \|= SSUSB_U2_PORT_FORCE_IDDIG \| SSUSB_U2_PORT_RG_IDDIG;
	402	break;
	403	case MTU3_DR_FORCE_HOST:
	404	value \|= SSUSB_U2_PORT_FORCE_IDDIG;
	405	value &= ~SSUSB_U2_PORT_RG_IDDIG;
	406	break;
	407	case MTU3_DR_FORCE_NONE:
	408	value &= ~(SSUSB_U2_PORT_FORCE_IDDIG \| SSUSB_U2_PORT_RG_IDDIG);
	409	break;
	410	default:
	411	return;
	412	}
	413	mtu3_writel(ssusb->ippc_base, SSUSB_U2_CTRL(0), value);
	414	}
	415
d0ed062a CY	416	int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)
	417	{
	418	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
	419
c776f2c3	420	if (otg_sx->manual_drd_enabled) {
d0ed062a	421	ssusb_debugfs_init(ssusb);
c776f2c3 CY	422	} else {
	423	INIT_DELAYED_WORK(&otg_sx->extcon_reg_dwork,
	424	extcon_register_dwork);
	425
	426	/*
	427	* It is enough to delay 1s for waiting for
	428	* host initialization
	429	*/
	430	schedule_delayed_work(&otg_sx->extcon_reg_dwork, HZ);
	431	}
d0ed062a CY	432
	433	return 0;
	434	}
	435
	436	void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb)
	437	{
	438	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
	439
d0ed062a CY	440	if (otg_sx->manual_drd_enabled)
d0ed062a CY	441	ssusb_debugfs_exit(ssusb);
c776f2c3 CY	442	else
c776f2c3 CY	443	cancel_delayed_work(&otg_sx->extcon_reg_dwork);
d0ed062a	444	}