drivers/usb/mtu3/mtu3_dr.c

   1 // SPDX-License-Identifier: GPL-2.0
   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
  10 #include "mtu3.h"
  11 #include "mtu3_dr.h"
  12 #include "mtu3_debug.h"
  13
  14 #define USB2_PORT 2
  15 #define USB3_PORT 3
  16
  17 static inline struct ssusb_mtk *otg_sx_to_ssusb(struct otg_switch_mtk *otg_sx)
  18 {
  19         return container_of(otg_sx, struct ssusb_mtk, otg_switch);
  20 }
  21
  22 static void toggle_opstate(struct ssusb_mtk *ssusb)
  23 {
  24         mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION);
  25         mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN);
  26 }
  27
  28 /* only port0 supports dual-role mode */
  29 static int ssusb_port0_switch(struct ssusb_mtk *ssusb,
  30         int version, bool tohost)
  31 {
  32         void __iomem *ibase = ssusb->ippc_base;
  33         u32 value;
  34
  35         dev_dbg(ssusb->dev, "%s (switch u%d port0 to %s)\n", __func__,
  36                 version, tohost ? "host" : "device");
  37
  38         if (version == USB2_PORT) {
  39                 /* 1. power off and disable u2 port0 */
  40                 value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
  41                 value |= SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS;
  42                 mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
  43
  44                 /* 2. power on, enable u2 port0 and select its mode */
  45                 value = mtu3_readl(ibase, SSUSB_U2_CTRL(0));
  46                 value &= ~(SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS);
  47                 value = tohost ? (value | SSUSB_U2_PORT_HOST_SEL) :
  48                         (value & (~SSUSB_U2_PORT_HOST_SEL));
  49                 mtu3_writel(ibase, SSUSB_U2_CTRL(0), value);
  50         } else {
  51                 /* 1. power off and disable u3 port0 */
  52                 value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
  53                 value |= SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS;
  54                 mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
  55
  56                 /* 2. power on, enable u3 port0 and select its mode */
  57                 value = mtu3_readl(ibase, SSUSB_U3_CTRL(0));
  58                 value &= ~(SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS);
  59                 value = tohost ? (value | SSUSB_U3_PORT_HOST_SEL) :
  60                         (value & (~SSUSB_U3_PORT_HOST_SEL));
  61                 mtu3_writel(ibase, SSUSB_U3_CTRL(0), value);
  62         }
  63
  64         return 0;
  65 }
  66
  67 static void switch_port_to_host(struct ssusb_mtk *ssusb)
  68 {
  69         u32 check_clk = 0;
  70
  71         dev_dbg(ssusb->dev, "%s\n", __func__);
  72
  73         ssusb_port0_switch(ssusb, USB2_PORT, true);
  74
  75         if (ssusb->otg_switch.is_u3_drd) {
  76                 ssusb_port0_switch(ssusb, USB3_PORT, true);
  77                 check_clk = SSUSB_U3_MAC_RST_B_STS;
  78         }
  79
  80         ssusb_check_clocks(ssusb, check_clk);
  81
  82         /* after all clocks are stable */
  83         toggle_opstate(ssusb);
  84 }
  85
  86 static void switch_port_to_device(struct ssusb_mtk *ssusb)
  87 {
  88         u32 check_clk = 0;
  89
  90         dev_dbg(ssusb->dev, "%s\n", __func__);
  91
  92         ssusb_port0_switch(ssusb, USB2_PORT, false);
  93
  94         if (ssusb->otg_switch.is_u3_drd) {
  95                 ssusb_port0_switch(ssusb, USB3_PORT, false);
  96                 check_clk = SSUSB_U3_MAC_RST_B_STS;
  97         }
  98
  99         ssusb_check_clocks(ssusb, check_clk);
 100 }
 101
 102 int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on)
 103 {
 104         struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
 105         struct regulator *vbus = otg_sx->vbus;
 106         int ret;
 107
 108         /* vbus is optional */
 109         if (!vbus)
 110                 return 0;
 111
 112         dev_dbg(ssusb->dev, "%s: turn %s\n", __func__, is_on ? "on" : "off");
 113
 114         if (is_on) {
 115                 ret = regulator_enable(vbus);
 116                 if (ret) {
 117                         dev_err(ssusb->dev, "vbus regulator enable failed\n");
 118                         return ret;
 119                 }
 120         } else {
 121                 regulator_disable(vbus);
 122         }
 123
 124         return 0;
 125 }
 126
 127 static void ssusb_mode_sw_work(struct work_struct *work)
 128 {
 129         struct otg_switch_mtk *otg_sx =
 130                 container_of(work, struct otg_switch_mtk, dr_work);
 131         struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
 132         struct mtu3 *mtu = ssusb->u3d;
 133         enum usb_role desired_role = otg_sx->desired_role;
 134         enum usb_role current_role;
 135
 136         current_role = ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE;
 137
 138         if (desired_role == USB_ROLE_NONE) {
 139                 /* the default mode is host as probe does */
 140                 desired_role = USB_ROLE_HOST;
 141                 if (otg_sx->default_role == USB_ROLE_DEVICE)
 142                         desired_role = USB_ROLE_DEVICE;
 143         }
 144
 145         if (current_role == desired_role)
 146                 return;
 147
 148         dev_dbg(ssusb->dev, "set role : %s\n", usb_role_string(desired_role));
 149         mtu3_dbg_trace(ssusb->dev, "set role : %s", usb_role_string(desired_role));
 150         pm_runtime_get_sync(ssusb->dev);
 151
 152         switch (desired_role) {
 153         case USB_ROLE_HOST:
 154                 ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_HOST);
 155                 mtu3_stop(mtu);
 156                 switch_port_to_host(ssusb);
 157                 ssusb_set_vbus(otg_sx, 1);
 158                 ssusb->is_host = true;
 159                 break;
 160         case USB_ROLE_DEVICE:
 161                 ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_DEVICE);
 162                 ssusb->is_host = false;
 163                 ssusb_set_vbus(otg_sx, 0);
 164                 switch_port_to_device(ssusb);
 165                 mtu3_start(mtu);
 166                 break;
 167         case USB_ROLE_NONE:
 168         default:
 169                 dev_err(ssusb->dev, "invalid role\n");
 170         }
 171         pm_runtime_put(ssusb->dev);
 172 }
 173
 174 static void ssusb_set_mode(struct otg_switch_mtk *otg_sx, enum usb_role role)
 175 {
 176         struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
 177
 178         if (ssusb->dr_mode != USB_DR_MODE_OTG)
 179                 return;
 180
 181         otg_sx->desired_role = role;
 182         queue_work(system_freezable_wq, &otg_sx->dr_work);
 183 }
 184
 185 static int ssusb_id_notifier(struct notifier_block *nb,
 186         unsigned long event, void *ptr)
 187 {
 188         struct otg_switch_mtk *otg_sx =
 189                 container_of(nb, struct otg_switch_mtk, id_nb);
 190
 191         ssusb_set_mode(otg_sx, event ? USB_ROLE_HOST : USB_ROLE_DEVICE);
 192
 193         return NOTIFY_DONE;
 194 }
 195
 196 static int ssusb_extcon_register(struct otg_switch_mtk *otg_sx)
 197 {
 198         struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
 199         struct extcon_dev *edev = otg_sx->edev;
 200         int ret;
 201
 202         /* extcon is optional */
 203         if (!edev)
 204                 return 0;
 205
 206         otg_sx->id_nb.notifier_call = ssusb_id_notifier;
 207         ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB_HOST,
 208                                         &otg_sx->id_nb);
 209         if (ret < 0) {
 210                 dev_err(ssusb->dev, "failed to register notifier for USB-HOST\n");
 211                 return ret;
 212         }
 213
 214         ret = extcon_get_state(edev, EXTCON_USB_HOST);
 215         dev_dbg(ssusb->dev, "EXTCON_USB_HOST: %d\n", ret);
 216
 217         /* default as host, switch to device mode if needed */
 218         if (!ret)
 219                 ssusb_set_mode(otg_sx, USB_ROLE_DEVICE);
 220
 221         return 0;
 222 }
 223
 224 /*
 225  * We provide an interface via debugfs to switch between host and device modes
 226  * depending on user input.
 227  * This is useful in special cases, such as uses TYPE-A receptacle but also
 228  * wants to support dual-role mode.
 229  */
 230 void ssusb_mode_switch(struct ssusb_mtk *ssusb, int to_host)
 231 {
 232         struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
 233
 234         ssusb_set_mode(otg_sx, to_host ? USB_ROLE_HOST : USB_ROLE_DEVICE);
 235 }
 236
 237 void ssusb_set_force_mode(struct ssusb_mtk *ssusb,
 238                           enum mtu3_dr_force_mode mode)
 239 {
 240         u32 value;
 241
 242         value = mtu3_readl(ssusb->ippc_base, SSUSB_U2_CTRL(0));
 243         switch (mode) {
 244         case MTU3_DR_FORCE_DEVICE:
 245                 value |= SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG;
 246                 break;
 247         case MTU3_DR_FORCE_HOST:
 248                 value |= SSUSB_U2_PORT_FORCE_IDDIG;
 249                 value &= ~SSUSB_U2_PORT_RG_IDDIG;
 250                 break;
 251         case MTU3_DR_FORCE_NONE:
 252                 value &= ~(SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG);
 253                 break;
 254         default:
 255                 return;
 256         }
 257         mtu3_writel(ssusb->ippc_base, SSUSB_U2_CTRL(0), value);
 258 }
 259
 260 static int ssusb_role_sw_set(struct usb_role_switch *sw, enum usb_role role)
 261 {
 262         struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
 263         struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
 264
 265         ssusb_set_mode(otg_sx, role);
 266
 267         return 0;
 268 }
 269
 270 static enum usb_role ssusb_role_sw_get(struct usb_role_switch *sw)
 271 {
 272         struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw);
 273
 274         return ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE;
 275 }
 276
 277 static int ssusb_role_sw_register(struct otg_switch_mtk *otg_sx)
 278 {
 279         struct usb_role_switch_desc role_sx_desc = { 0 };
 280         struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx);
 281         struct device *dev = ssusb->dev;
 282         enum usb_dr_mode mode;
 283
 284         if (!otg_sx->role_sw_used)
 285                 return 0;
 286
 287         mode = usb_get_role_switch_default_mode(dev);
 288         if (mode == USB_DR_MODE_PERIPHERAL)
 289                 otg_sx->default_role = USB_ROLE_DEVICE;
 290         else
 291                 otg_sx->default_role = USB_ROLE_HOST;
 292
 293         role_sx_desc.set = ssusb_role_sw_set;
 294         role_sx_desc.get = ssusb_role_sw_get;
 295         role_sx_desc.fwnode = dev_fwnode(dev);
 296         role_sx_desc.driver_data = ssusb;
 297         role_sx_desc.allow_userspace_control = true;
 298         otg_sx->role_sw = usb_role_switch_register(dev, &role_sx_desc);
 299         if (IS_ERR(otg_sx->role_sw))
 300                 return PTR_ERR(otg_sx->role_sw);
 301
 302         ssusb_set_mode(otg_sx, otg_sx->default_role);
 303
 304         return 0;
 305 }
 306
 307 int ssusb_otg_switch_init(struct ssusb_mtk *ssusb)
 308 {
 309         struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
 310         int ret = 0;
 311
 312         INIT_WORK(&otg_sx->dr_work, ssusb_mode_sw_work);
 313
 314         if (otg_sx->manual_drd_enabled)
 315                 ssusb_dr_debugfs_init(ssusb);
 316         else if (otg_sx->role_sw_used)
 317                 ret = ssusb_role_sw_register(otg_sx);
 318         else
 319                 ret = ssusb_extcon_register(otg_sx);
 320
 321         return ret;
 322 }
 323
 324 void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb)
 325 {
 326         struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
 327
 328         cancel_work_sync(&otg_sx->dr_work);
 329         usb_role_switch_unregister(otg_sx->role_sw);
 330 }