diff options
author | Chunfeng Yun <chunfeng.yun@mediatek.com> | 2016-10-19 05:28:26 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-10-27 18:02:41 +0300 |
commit | d0ed062a8b75b9c9ba5a942894636f2d9bb72040 (patch) | |
tree | 13f0860c5451f03778668e823b7c9321b5089d00 /drivers/usb/mtu3/mtu3_dr.c | |
parent | b3f4e727c1ecec36e628e89298349d9c51a32aac (diff) | |
download | linux-d0ed062a8b75b9c9ba5a942894636f2d9bb72040.tar.xz |
usb: mtu3: dual-role mode support
support dual-role mode; there are two ways to switch between
host and device modes, one is by idpin, another is by debugfs
which depends on user input.
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/mtu3/mtu3_dr.c')
-rw-r--r-- | drivers/usb/mtu3/mtu3_dr.c | 379 |
1 files changed, 379 insertions, 0 deletions
diff --git a/drivers/usb/mtu3/mtu3_dr.c b/drivers/usb/mtu3/mtu3_dr.c new file mode 100644 index 000000000000..1a8987e7c5b0 --- /dev/null +++ b/drivers/usb/mtu3/mtu3_dr.c @@ -0,0 +1,379 @@ +/* + * 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 = extcon_register_notifier(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 = extcon_register_notifier(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_cable_state_(edev, EXTCON_USB), + extcon_get_cable_state_(edev, EXTCON_USB_HOST)); + + /* default as host, switch to device mode if needed */ + if (extcon_get_cable_state_(edev, EXTCON_USB_HOST) == false) + ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT); + if (extcon_get_cable_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. + * It generates cable state changes by pulling up/down IDPIN and + * notifies driver to switch mode by "extcon-usb-gpio". + * NOTE: when use MICRO receptacle, should not enable this interface. + */ +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) + pinctrl_select_state(otg_sx->id_pinctrl, otg_sx->id_ground); + else + pinctrl_select_state(otg_sx->id_pinctrl, otg_sx->id_float); +} + + +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 void ssusb_debugfs_init(struct ssusb_mtk *ssusb) +{ + struct dentry *root; + struct dentry *file; + + root = debugfs_create_dir(dev_name(ssusb->dev), usb_debug_root); + if (IS_ERR_OR_NULL(root)) { + if (!root) + dev_err(ssusb->dev, "create debugfs root failed\n"); + return; + } + ssusb->dbgfs_root = root; + + file = debugfs_create_file("mode", S_IRUGO | S_IWUSR, root, + ssusb, &ssusb_mode_fops); + if (!file) + dev_dbg(ssusb->dev, "create debugfs mode failed\n"); +} + +static void ssusb_debugfs_exit(struct ssusb_mtk *ssusb) +{ + debugfs_remove_recursive(ssusb->dbgfs_root); +} + +int ssusb_otg_switch_init(struct ssusb_mtk *ssusb) +{ + struct otg_switch_mtk *otg_sx = &ssusb->otg_switch; + + INIT_DELAYED_WORK(&otg_sx->extcon_reg_dwork, extcon_register_dwork); + + if (otg_sx->manual_drd_enabled) + ssusb_debugfs_init(ssusb); + + /* 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; + + cancel_delayed_work(&otg_sx->extcon_reg_dwork); + + if (otg_sx->edev) { + extcon_unregister_notifier(otg_sx->edev, + EXTCON_USB, &otg_sx->vbus_nb); + extcon_unregister_notifier(otg_sx->edev, + EXTCON_USB_HOST, &otg_sx->id_nb); + } + + if (otg_sx->manual_drd_enabled) + ssusb_debugfs_exit(ssusb); +} |