| 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 <linux/string_choices.h> |
| 11 | #include "mtu3.h" |
| 12 | #include "mtu3_dr.h" |
| 13 | #include "mtu3_debug.h" |
| 14 | |
| 15 | #define USB2_PORT 2 |
| 16 | #define USB3_PORT 3 |
| 17 | |
| 18 | static inline struct ssusb_mtk *otg_sx_to_ssusb(struct otg_switch_mtk *otg_sx) |
| 19 | { |
| 20 | return container_of(otg_sx, struct ssusb_mtk, otg_switch); |
| 21 | } |
| 22 | |
| 23 | static void toggle_opstate(struct ssusb_mtk *ssusb) |
| 24 | { |
| 25 | mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION); |
| 26 | mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN); |
| 27 | } |
| 28 | |
| 29 | /* only port0 supports dual-role mode */ |
| 30 | static int ssusb_port0_switch(struct ssusb_mtk *ssusb, |
| 31 | int version, bool tohost) |
| 32 | { |
| 33 | void __iomem *ibase = ssusb->ippc_base; |
| 34 | u32 value; |
| 35 | |
| 36 | dev_dbg(ssusb->dev, "%s (switch u%d port0 to %s)\n", __func__, |
| 37 | version, tohost ? "host" : "device"); |
| 38 | |
| 39 | if (version == USB2_PORT) { |
| 40 | /* 1. power off and disable u2 port0 */ |
| 41 | value = mtu3_readl(ibase, SSUSB_U2_CTRL(0)); |
| 42 | value |= SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS; |
| 43 | mtu3_writel(ibase, SSUSB_U2_CTRL(0), value); |
| 44 | |
| 45 | /* 2. power on, enable u2 port0 and select its mode */ |
| 46 | value = mtu3_readl(ibase, SSUSB_U2_CTRL(0)); |
| 47 | value &= ~(SSUSB_U2_PORT_PDN | SSUSB_U2_PORT_DIS); |
| 48 | value = tohost ? (value | SSUSB_U2_PORT_HOST_SEL) : |
| 49 | (value & (~SSUSB_U2_PORT_HOST_SEL)); |
| 50 | mtu3_writel(ibase, SSUSB_U2_CTRL(0), value); |
| 51 | } else { |
| 52 | /* 1. power off and disable u3 port0 */ |
| 53 | value = mtu3_readl(ibase, SSUSB_U3_CTRL(0)); |
| 54 | value |= SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS; |
| 55 | mtu3_writel(ibase, SSUSB_U3_CTRL(0), value); |
| 56 | |
| 57 | /* 2. power on, enable u3 port0 and select its mode */ |
| 58 | value = mtu3_readl(ibase, SSUSB_U3_CTRL(0)); |
| 59 | value &= ~(SSUSB_U3_PORT_PDN | SSUSB_U3_PORT_DIS); |
| 60 | value = tohost ? (value | SSUSB_U3_PORT_HOST_SEL) : |
| 61 | (value & (~SSUSB_U3_PORT_HOST_SEL)); |
| 62 | mtu3_writel(ibase, SSUSB_U3_CTRL(0), value); |
| 63 | } |
| 64 | |
| 65 | return 0; |
| 66 | } |
| 67 | |
| 68 | static void switch_port_to_host(struct ssusb_mtk *ssusb) |
| 69 | { |
| 70 | u32 check_clk = 0; |
| 71 | |
| 72 | dev_dbg(ssusb->dev, "%s\n", __func__); |
| 73 | |
| 74 | ssusb_port0_switch(ssusb, USB2_PORT, true); |
| 75 | |
| 76 | if (ssusb->otg_switch.is_u3_drd) { |
| 77 | ssusb_port0_switch(ssusb, USB3_PORT, true); |
| 78 | check_clk = SSUSB_U3_MAC_RST_B_STS; |
| 79 | } |
| 80 | |
| 81 | ssusb_check_clocks(ssusb, check_clk); |
| 82 | |
| 83 | /* after all clocks are stable */ |
| 84 | toggle_opstate(ssusb); |
| 85 | } |
| 86 | |
| 87 | static void switch_port_to_device(struct ssusb_mtk *ssusb) |
| 88 | { |
| 89 | u32 check_clk = 0; |
| 90 | |
| 91 | dev_dbg(ssusb->dev, "%s\n", __func__); |
| 92 | |
| 93 | ssusb_port0_switch(ssusb, USB2_PORT, false); |
| 94 | |
| 95 | if (ssusb->otg_switch.is_u3_drd) { |
| 96 | ssusb_port0_switch(ssusb, USB3_PORT, false); |
| 97 | check_clk = SSUSB_U3_MAC_RST_B_STS; |
| 98 | } |
| 99 | |
| 100 | ssusb_check_clocks(ssusb, check_clk); |
| 101 | } |
| 102 | |
| 103 | int ssusb_set_vbus(struct otg_switch_mtk *otg_sx, int is_on) |
| 104 | { |
| 105 | struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx); |
| 106 | struct regulator *vbus = otg_sx->vbus; |
| 107 | int ret; |
| 108 | |
| 109 | /* vbus is optional */ |
| 110 | if (!vbus) |
| 111 | return 0; |
| 112 | |
| 113 | dev_dbg(ssusb->dev, "%s: turn %s\n", __func__, str_on_off(is_on)); |
| 114 | |
| 115 | if (is_on) { |
| 116 | ret = regulator_enable(vbus); |
| 117 | if (ret) { |
| 118 | dev_err(ssusb->dev, "vbus regulator enable failed\n"); |
| 119 | return ret; |
| 120 | } |
| 121 | } else { |
| 122 | regulator_disable(vbus); |
| 123 | } |
| 124 | |
| 125 | return 0; |
| 126 | } |
| 127 | |
| 128 | static void ssusb_mode_sw_work(struct work_struct *work) |
| 129 | { |
| 130 | struct otg_switch_mtk *otg_sx = |
| 131 | container_of(work, struct otg_switch_mtk, dr_work); |
| 132 | struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx); |
| 133 | struct mtu3 *mtu = ssusb->u3d; |
| 134 | enum usb_role desired_role = otg_sx->desired_role; |
| 135 | enum usb_role current_role; |
| 136 | |
| 137 | current_role = ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE; |
| 138 | |
| 139 | if (desired_role == USB_ROLE_NONE) { |
| 140 | /* the default mode is host as probe does */ |
| 141 | desired_role = USB_ROLE_HOST; |
| 142 | if (otg_sx->default_role == USB_ROLE_DEVICE) |
| 143 | desired_role = USB_ROLE_DEVICE; |
| 144 | } |
| 145 | |
| 146 | if (current_role == desired_role) |
| 147 | return; |
| 148 | |
| 149 | dev_dbg(ssusb->dev, "set role : %s\n", usb_role_string(desired_role)); |
| 150 | mtu3_dbg_trace(ssusb->dev, "set role : %s", usb_role_string(desired_role)); |
| 151 | pm_runtime_get_sync(ssusb->dev); |
| 152 | |
| 153 | switch (desired_role) { |
| 154 | case USB_ROLE_HOST: |
| 155 | ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_HOST); |
| 156 | mtu3_stop(mtu); |
| 157 | switch_port_to_host(ssusb); |
| 158 | ssusb_set_vbus(otg_sx, 1); |
| 159 | ssusb->is_host = true; |
| 160 | break; |
| 161 | case USB_ROLE_DEVICE: |
| 162 | ssusb_set_force_mode(ssusb, MTU3_DR_FORCE_DEVICE); |
| 163 | ssusb->is_host = false; |
| 164 | ssusb_set_vbus(otg_sx, 0); |
| 165 | switch_port_to_device(ssusb); |
| 166 | mtu3_start(mtu); |
| 167 | break; |
| 168 | case USB_ROLE_NONE: |
| 169 | default: |
| 170 | dev_err(ssusb->dev, "invalid role\n"); |
| 171 | } |
| 172 | pm_runtime_put(ssusb->dev); |
| 173 | } |
| 174 | |
| 175 | static void ssusb_set_mode(struct otg_switch_mtk *otg_sx, enum usb_role role) |
| 176 | { |
| 177 | struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx); |
| 178 | |
| 179 | if (ssusb->dr_mode != USB_DR_MODE_OTG) |
| 180 | return; |
| 181 | |
| 182 | otg_sx->desired_role = role; |
| 183 | queue_work(system_freezable_wq, &otg_sx->dr_work); |
| 184 | } |
| 185 | |
| 186 | static int ssusb_id_notifier(struct notifier_block *nb, |
| 187 | unsigned long event, void *ptr) |
| 188 | { |
| 189 | struct otg_switch_mtk *otg_sx = |
| 190 | container_of(nb, struct otg_switch_mtk, id_nb); |
| 191 | |
| 192 | ssusb_set_mode(otg_sx, event ? USB_ROLE_HOST : USB_ROLE_DEVICE); |
| 193 | |
| 194 | return NOTIFY_DONE; |
| 195 | } |
| 196 | |
| 197 | static int ssusb_extcon_register(struct otg_switch_mtk *otg_sx) |
| 198 | { |
| 199 | struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx); |
| 200 | struct extcon_dev *edev = otg_sx->edev; |
| 201 | int ret; |
| 202 | |
| 203 | /* extcon is optional */ |
| 204 | if (!edev) |
| 205 | return 0; |
| 206 | |
| 207 | otg_sx->id_nb.notifier_call = ssusb_id_notifier; |
| 208 | ret = devm_extcon_register_notifier(ssusb->dev, edev, EXTCON_USB_HOST, |
| 209 | &otg_sx->id_nb); |
| 210 | if (ret < 0) { |
| 211 | dev_err(ssusb->dev, "failed to register notifier for USB-HOST\n"); |
| 212 | return ret; |
| 213 | } |
| 214 | |
| 215 | ret = extcon_get_state(edev, EXTCON_USB_HOST); |
| 216 | dev_dbg(ssusb->dev, "EXTCON_USB_HOST: %d\n", ret); |
| 217 | |
| 218 | /* default as host, switch to device mode if needed */ |
| 219 | if (!ret) |
| 220 | ssusb_set_mode(otg_sx, USB_ROLE_DEVICE); |
| 221 | |
| 222 | return 0; |
| 223 | } |
| 224 | |
| 225 | /* |
| 226 | * We provide an interface via debugfs to switch between host and device modes |
| 227 | * depending on user input. |
| 228 | * This is useful in special cases, such as uses TYPE-A receptacle but also |
| 229 | * wants to support dual-role mode. |
| 230 | */ |
| 231 | void ssusb_mode_switch(struct ssusb_mtk *ssusb, int to_host) |
| 232 | { |
| 233 | struct otg_switch_mtk *otg_sx = &ssusb->otg_switch; |
| 234 | |
| 235 | ssusb_set_mode(otg_sx, to_host ? USB_ROLE_HOST : USB_ROLE_DEVICE); |
| 236 | } |
| 237 | |
| 238 | void ssusb_set_force_mode(struct ssusb_mtk *ssusb, |
| 239 | enum mtu3_dr_force_mode mode) |
| 240 | { |
| 241 | u32 value; |
| 242 | |
| 243 | value = mtu3_readl(ssusb->ippc_base, SSUSB_U2_CTRL(0)); |
| 244 | switch (mode) { |
| 245 | case MTU3_DR_FORCE_DEVICE: |
| 246 | value |= SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG; |
| 247 | break; |
| 248 | case MTU3_DR_FORCE_HOST: |
| 249 | value |= SSUSB_U2_PORT_FORCE_IDDIG; |
| 250 | value &= ~SSUSB_U2_PORT_RG_IDDIG; |
| 251 | break; |
| 252 | case MTU3_DR_FORCE_NONE: |
| 253 | value &= ~(SSUSB_U2_PORT_FORCE_IDDIG | SSUSB_U2_PORT_RG_IDDIG); |
| 254 | break; |
| 255 | default: |
| 256 | return; |
| 257 | } |
| 258 | mtu3_writel(ssusb->ippc_base, SSUSB_U2_CTRL(0), value); |
| 259 | } |
| 260 | |
| 261 | static int ssusb_role_sw_set(struct usb_role_switch *sw, enum usb_role role) |
| 262 | { |
| 263 | struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw); |
| 264 | struct otg_switch_mtk *otg_sx = &ssusb->otg_switch; |
| 265 | |
| 266 | ssusb_set_mode(otg_sx, role); |
| 267 | |
| 268 | return 0; |
| 269 | } |
| 270 | |
| 271 | static enum usb_role ssusb_role_sw_get(struct usb_role_switch *sw) |
| 272 | { |
| 273 | struct ssusb_mtk *ssusb = usb_role_switch_get_drvdata(sw); |
| 274 | |
| 275 | return ssusb->is_host ? USB_ROLE_HOST : USB_ROLE_DEVICE; |
| 276 | } |
| 277 | |
| 278 | static int ssusb_role_sw_register(struct otg_switch_mtk *otg_sx) |
| 279 | { |
| 280 | struct usb_role_switch_desc role_sx_desc = { 0 }; |
| 281 | struct ssusb_mtk *ssusb = otg_sx_to_ssusb(otg_sx); |
| 282 | struct device *dev = ssusb->dev; |
| 283 | enum usb_dr_mode mode; |
| 284 | |
| 285 | if (!otg_sx->role_sw_used) |
| 286 | return 0; |
| 287 | |
| 288 | mode = usb_get_role_switch_default_mode(dev); |
| 289 | if (mode == USB_DR_MODE_PERIPHERAL) |
| 290 | otg_sx->default_role = USB_ROLE_DEVICE; |
| 291 | else |
| 292 | otg_sx->default_role = USB_ROLE_HOST; |
| 293 | |
| 294 | role_sx_desc.set = ssusb_role_sw_set; |
| 295 | role_sx_desc.get = ssusb_role_sw_get; |
| 296 | role_sx_desc.fwnode = dev_fwnode(dev); |
| 297 | role_sx_desc.driver_data = ssusb; |
| 298 | role_sx_desc.allow_userspace_control = true; |
| 299 | otg_sx->role_sw = usb_role_switch_register(dev, &role_sx_desc); |
| 300 | if (IS_ERR(otg_sx->role_sw)) |
| 301 | return PTR_ERR(otg_sx->role_sw); |
| 302 | |
| 303 | ssusb_set_mode(otg_sx, otg_sx->default_role); |
| 304 | |
| 305 | return 0; |
| 306 | } |
| 307 | |
| 308 | int ssusb_otg_switch_init(struct ssusb_mtk *ssusb) |
| 309 | { |
| 310 | struct otg_switch_mtk *otg_sx = &ssusb->otg_switch; |
| 311 | int ret = 0; |
| 312 | |
| 313 | INIT_WORK(&otg_sx->dr_work, ssusb_mode_sw_work); |
| 314 | |
| 315 | if (otg_sx->manual_drd_enabled) |
| 316 | ssusb_dr_debugfs_init(ssusb); |
| 317 | else if (otg_sx->role_sw_used) |
| 318 | ret = ssusb_role_sw_register(otg_sx); |
| 319 | else |
| 320 | ret = ssusb_extcon_register(otg_sx); |
| 321 | |
| 322 | return ret; |
| 323 | } |
| 324 | |
| 325 | void ssusb_otg_switch_exit(struct ssusb_mtk *ssusb) |
| 326 | { |
| 327 | struct otg_switch_mtk *otg_sx = &ssusb->otg_switch; |
| 328 | |
| 329 | cancel_work_sync(&otg_sx->dr_work); |
| 330 | usb_role_switch_unregister(otg_sx->role_sw); |
| 331 | } |