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Diffstat (limited to '')
| -rw-r--r-- | drivers/usb/mtu3/mtu3_dr.c | 388 |
1 files changed, 388 insertions, 0 deletions
diff --git a/drivers/usb/mtu3/mtu3_dr.c b/drivers/usb/mtu3/mtu3_dr.c new file mode 100644 index 000000000..16731324e --- /dev/null +++ b/drivers/usb/mtu3/mtu3_dr.c @@ -0,0 +1,388 @@ +// 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> + */ + +#include <linux/usb/role.h> + +#include "mtu3.h" +#include "mtu3_dr.h" +#include "mtu3_debug.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 char *mailbox_state_string(enum mtu3_vbus_id_state state) +{ + switch (state) { + case MTU3_ID_FLOAT: + return "ID_FLOAT"; + case MTU3_ID_GROUND: + return "ID_GROUND"; + case MTU3_VBUS_OFF: + return "VBUS_OFF"; + case MTU3_VBUS_VALID: + return "VBUS_VALID"; + default: + return "UNKNOWN"; + } +} + +static void toggle_opstate(struct ssusb_mtk *ssusb) +{ + 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 %s\n", mailbox_state_string(status)); + mtu3_dbg_trace(ssusb->dev, "mailbox %s", mailbox_state_string(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 void ssusb_id_work(struct work_struct *work) +{ + struct otg_switch_mtk *otg_sx = + container_of(work, struct otg_switch_mtk, id_work); + + if (otg_sx->id_event) + ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND); + else + ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT); +} + +static void ssusb_vbus_work(struct work_struct *work) +{ + struct otg_switch_mtk *otg_sx = + container_of(work, struct otg_switch_mtk, vbus_work); + + if (otg_sx->vbus_event) + ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID); + else + ssusb_set_mailbox(otg_sx, MTU3_VBUS_OFF); +} + +/* + * @ssusb_id_notifier is called in atomic context, but @ssusb_set_mailbox + * may sleep, so use work queue here + */ +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); + + otg_sx->id_event = event; + schedule_work(&otg_sx->id_work); + + 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); + + otg_sx->vbus_event = event; + schedule_work(&otg_sx->vbus_work); + + 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"); + return ret; + } + + 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"); + return ret; + } + + 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; +} + +/* + * 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. + */ +void ssusb_mode_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); + } +} + +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); +} + +static int ssusb_role_sw_set(struct usb_role_switch *sw, enum usb_role role) +{ + struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw); + bool to_host = false; + + if (role == USB_ROLE_HOST) + to_host = true; + + if (to_host ^ ssusb->is_host) + ssusb_mode_switch(ssusb, to_host); + + return 0; +} + +static enum usb_role ssusb_role_sw_get(struct usb_role_switch *sw) +{ + struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw); + enum usb_role role; + + role = ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE; + + return role; +} + +static int ssusb_role_sw_register(struct otg_switch_mtk *otg_sx) +{ + struct usb_role_switch_desc role_sx_desc = { 0 }; + struct ssusb_mtk *ssusb = + container_of(otg_sx, struct ssusb_mtk, otg_switch); + + if (!otg_sx->role_sw_used) + return 0; + + role_sx_desc.set = ssusb_role_sw_set; + role_sx_desc.get = ssusb_role_sw_get; + role_sx_desc.fwnode = dev_fwnode(ssusb->dev); + role_sx_desc.driver_data = ssusb; + otg_sx->role_sw = usb_role_switch_register(ssusb->dev, &role_sx_desc); + + return PTR_ERR_OR_ZERO(otg_sx->role_sw); +} + +int ssusb_otg_switch_init(struct ssusb_mtk *ssusb) +{ + struct otg_switch_mtk *otg_sx = &ssusb->otg_switch; + int ret = 0; + + INIT_WORK(&otg_sx->id_work, ssusb_id_work); + INIT_WORK(&otg_sx->vbus_work, ssusb_vbus_work); + + if (otg_sx->manual_drd_enabled) + ssusb_dr_debugfs_init(ssusb); + else if (otg_sx->role_sw_used) + ret = ssusb_role_sw_register(otg_sx); + else + ret = ssusb_extcon_register(otg_sx); + + return ret; +} + +void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb) +{ + struct otg_switch_mtk *otg_sx = &ssusb->otg_switch; + + cancel_work_sync(&otg_sx->id_work); + cancel_work_sync(&otg_sx->vbus_work); + usb_role_switch_unregister(otg_sx->role_sw); +} |