391 lines
9.5 KiB
C
391 lines
9.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* mtu3_dr.c - dual role switch and host glue layer
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*
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* Copyright (C) 2016 MediaTek Inc.
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*
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* Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
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*/
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#include <linux/usb/role.h>
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#include "mtu3.h"
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#include "mtu3_dr.h"
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#include "mtu3_debug.h"
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#define USB2_PORT 2
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#define USB3_PORT 3
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enum mtu3_vbus_id_state {
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MTU3_ID_FLOAT = 1,
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MTU3_ID_GROUND,
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MTU3_VBUS_OFF,
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MTU3_VBUS_VALID,
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};
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static char *mailbox_state_string(enum mtu3_vbus_id_state state)
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{
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switch (state) {
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case MTU3_ID_FLOAT:
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return "ID_FLOAT";
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case MTU3_ID_GROUND:
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return "ID_GROUND";
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case MTU3_VBUS_OFF:
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return "VBUS_OFF";
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case MTU3_VBUS_VALID:
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return "VBUS_VALID";
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default:
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return "UNKNOWN";
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}
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}
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static void toggle_opstate(struct ssusb_mtk *ssusb)
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{
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if (!ssusb->otg_switch.is_u3_drd) {
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mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION);
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mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN);
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}
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}
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/* only port0 supports dual-role mode */
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static int ssusb_port0_switch(struct ssusb_mtk *ssusb,
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int version, bool tohost)
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{
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void __iomem *ibase = ssusb->ippc_base;
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u32 value;
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dev_dbg(ssusb->dev, "%s (switch u%d port0 to %s)\n", __func__,
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version, tohost ? "host" : "device");
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if (version == USB2_PORT) {
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/* 1. power off and disable u2 port0 */
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value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
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value |= SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS;
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mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
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/* 2. power on, enable u2 port0 and select its mode */
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value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
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value &= ~(SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS);
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value = tohost ? (value | SSUSB_U2_PORT_HOST_SEL) :
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(value & (~SSUSB_U2_PORT_HOST_SEL));
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mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
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} else {
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/* 1. power off and disable u3 port0 */
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value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
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value |= SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS;
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mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
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/* 2. power on, enable u3 port0 and select its mode */
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value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
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value &= ~(SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS);
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value = tohost ? (value | SSUSB_U3_PORT_HOST_SEL) :
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(value & (~SSUSB_U3_PORT_HOST_SEL));
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mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
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}
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return 0;
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}
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static void switch_port_to_host(struct ssusb_mtk *ssusb)
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{
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u32 check_clk = 0;
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dev_dbg(ssusb->dev, "%s\n", __func__);
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ssusb_port0_switch(ssusb, USB2_PORT, true);
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if (ssusb->otg_switch.is_u3_drd) {
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ssusb_port0_switch(ssusb, USB3_PORT, true);
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check_clk = SSUSB_U3_MAC_RST_B_STS;
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}
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ssusb_check_clocks(ssusb, check_clk);
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/* after all clocks are stable */
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toggle_opstate(ssusb);
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}
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static void switch_port_to_device(struct ssusb_mtk *ssusb)
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{
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u32 check_clk = 0;
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dev_dbg(ssusb->dev, "%s\n", __func__);
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ssusb_port0_switch(ssusb, USB2_PORT, false);
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if (ssusb->otg_switch.is_u3_drd) {
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ssusb_port0_switch(ssusb, USB3_PORT, false);
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check_clk = SSUSB_U3_MAC_RST_B_STS;
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}
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ssusb_check_clocks(ssusb, check_clk);
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}
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int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on)
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{
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struct ssusb_mtk *ssusb =
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container_of(otg_sx, struct ssusb_mtk, otg_switch);
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struct regulator *vbus = otg_sx->vbus;
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int ret;
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/* vbus is optional */
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if (!vbus)
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return 0;
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dev_dbg(ssusb->dev, "%s: turn %s\n", __func__, is_on ? "on" : "off");
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if (is_on) {
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ret = regulator_enable(vbus);
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if (ret) {
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dev_err(ssusb->dev, "vbus regulator enable failed\n");
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return ret;
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}
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} else {
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regulator_disable(vbus);
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}
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return 0;
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}
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/*
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* switch to host: -> MTU3_VBUS_OFF --> MTU3_ID_GROUND
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* switch to device: -> MTU3_ID_FLOAT --> MTU3_VBUS_VALID
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*/
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static void ssusb_set_mailbox(struct otg_switch_mtk *otg_sx,
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enum mtu3_vbus_id_state status)
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{
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struct ssusb_mtk *ssusb =
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container_of(otg_sx, struct ssusb_mtk, otg_switch);
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struct mtu3 *mtu = ssusb->u3d;
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dev_dbg(ssusb->dev, "mailbox %s\n", mailbox_state_string(status));
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mtu3_dbg_trace(ssusb->dev, "mailbox %s", mailbox_state_string(status));
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switch (status) {
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case MTU3_ID_GROUND:
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switch_port_to_host(ssusb);
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ssusb_set_vbus(otg_sx, 1);
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ssusb->is_host = true;
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break;
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case MTU3_ID_FLOAT:
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ssusb->is_host = false;
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ssusb_set_vbus(otg_sx, 0);
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switch_port_to_device(ssusb);
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break;
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case MTU3_VBUS_OFF:
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mtu3_stop(mtu);
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pm_relax(ssusb->dev);
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break;
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case MTU3_VBUS_VALID:
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/* avoid suspend when works as device */
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pm_stay_awake(ssusb->dev);
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mtu3_start(mtu);
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break;
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default:
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dev_err(ssusb->dev, "invalid state\n");
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}
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}
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static void ssusb_id_work(struct work_struct *work)
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{
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struct otg_switch_mtk *otg_sx =
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container_of(work, struct otg_switch_mtk, id_work);
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if (otg_sx->id_event)
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ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND);
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else
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ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
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}
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static void ssusb_vbus_work(struct work_struct *work)
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{
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struct otg_switch_mtk *otg_sx =
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container_of(work, struct otg_switch_mtk, vbus_work);
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if (otg_sx->vbus_event)
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ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
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else
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ssusb_set_mailbox(otg_sx, MTU3_VBUS_OFF);
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}
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/*
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* @ssusb_id_notifier is called in atomic context, but @ssusb_set_mailbox
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* may sleep, so use work queue here
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*/
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static int ssusb_id_notifier(struct notifier_block *nb,
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unsigned long event, void *ptr)
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{
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struct otg_switch_mtk *otg_sx =
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container_of(nb, struct otg_switch_mtk, id_nb);
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otg_sx->id_event = event;
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schedule_work(&otg_sx->id_work);
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return NOTIFY_DONE;
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}
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static int ssusb_vbus_notifier(struct notifier_block *nb,
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unsigned long event, void *ptr)
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{
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struct otg_switch_mtk *otg_sx =
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container_of(nb, struct otg_switch_mtk, vbus_nb);
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otg_sx->vbus_event = event;
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schedule_work(&otg_sx->vbus_work);
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return NOTIFY_DONE;
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}
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static int ssusb_extcon_register(struct otg_switch_mtk *otg_sx)
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{
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struct ssusb_mtk *ssusb =
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container_of(otg_sx, struct ssusb_mtk, otg_switch);
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struct extcon_dev *edev = otg_sx->edev;
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int ret;
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/* extcon is optional */
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if (!edev)
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return 0;
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otg_sx->vbus_nb.notifier_call = ssusb_vbus_notifier;
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ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB,
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&otg_sx->vbus_nb);
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if (ret < 0) {
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dev_err(ssusb->dev, "failed to register notifier for USB\n");
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return ret;
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}
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otg_sx->id_nb.notifier_call = ssusb_id_notifier;
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ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB_HOST,
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&otg_sx->id_nb);
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if (ret < 0) {
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dev_err(ssusb->dev, "failed to register notifier for USB-HOST\n");
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return ret;
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}
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dev_dbg(ssusb->dev, "EXTCON_USB: %d, EXTCON_USB_HOST: %d\n",
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extcon_get_state(edev, EXTCON_USB),
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extcon_get_state(edev, EXTCON_USB_HOST));
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/* default as host, switch to device mode if needed */
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if (extcon_get_state(edev, EXTCON_USB_HOST) == false)
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ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
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if (extcon_get_state(edev, EXTCON_USB) == true)
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ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
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return 0;
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}
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/*
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* We provide an interface via debugfs to switch between host and device modes
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* depending on user input.
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* This is useful in special cases, such as uses TYPE-A receptacle but also
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* wants to support dual-role mode.
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*/
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void ssusb_mode_switch(struct ssusb_mtk *ssusb, int to_host)
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{
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struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
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if (to_host) {
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ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_HOST);
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ssusb_set_mailbox(otg_sx, MTU3_VBUS_OFF);
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ssusb_set_mailbox(otg_sx, MTU3_ID_GROUND);
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} else {
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ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_DEVICE);
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ssusb_set_mailbox(otg_sx, MTU3_ID_FLOAT);
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ssusb_set_mailbox(otg_sx, MTU3_VBUS_VALID);
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}
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}
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void ssusb_set_force_mode(struct ssusb_mtk *ssusb,
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enum mtu3_dr_force_mode mode)
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{
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u32 value;
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value = mtu3_readl(ssusb->ippc_base, SSUSB_U2_CTRL(0));
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switch (mode) {
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case MTU3_DR_FORCE_DEVICE:
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value |= SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG;
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break;
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case MTU3_DR_FORCE_HOST:
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value |= SSUSB_U2_PORT_FORCE_IDDIG;
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value &= ~SSUSB_U2_PORT_RG_IDDIG;
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break;
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case MTU3_DR_FORCE_NONE:
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value &= ~(SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG);
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break;
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default:
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return;
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}
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mtu3_writel(ssusb->ippc_base, SSUSB_U2_CTRL(0), value);
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}
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static int ssusb_role_sw_set(struct usb_role_switch *sw, enum usb_role role)
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{
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struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
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bool to_host = false;
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if (role == USB_ROLE_HOST)
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to_host = true;
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if (to_host ^ ssusb->is_host)
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ssusb_mode_switch(ssusb, to_host);
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return 0;
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}
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static enum usb_role ssusb_role_sw_get(struct usb_role_switch *sw)
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{
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struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
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enum usb_role role;
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role = ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE;
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return role;
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}
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static int ssusb_role_sw_register(struct otg_switch_mtk *otg_sx)
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{
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struct usb_role_switch_desc role_sx_desc = { 0 };
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struct ssusb_mtk *ssusb =
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container_of(otg_sx, struct ssusb_mtk, otg_switch);
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if (!otg_sx->role_sw_used)
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return 0;
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role_sx_desc.set = ssusb_role_sw_set;
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role_sx_desc.get = ssusb_role_sw_get;
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role_sx_desc.fwnode = dev_fwnode(ssusb->dev);
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role_sx_desc.driver_data = ssusb;
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otg_sx->role_sw = usb_role_switch_register(ssusb->dev, &role_sx_desc);
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return PTR_ERR_OR_ZERO(otg_sx->role_sw);
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}
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int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)
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{
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struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
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int ret = 0;
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INIT_WORK(&otg_sx->id_work, ssusb_id_work);
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INIT_WORK(&otg_sx->vbus_work, ssusb_vbus_work);
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if (otg_sx->manual_drd_enabled)
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ssusb_dr_debugfs_init(ssusb);
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else if (otg_sx->role_sw_used)
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ret = ssusb_role_sw_register(otg_sx);
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else
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ret = ssusb_extcon_register(otg_sx);
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return ret;
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}
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void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb)
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{
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struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
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cancel_work_sync(&otg_sx->id_work);
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cancel_work_sync(&otg_sx->vbus_work);
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usb_role_switch_unregister(otg_sx->role_sw);
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}
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