drivers/usb/typec/port-mapper.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * USB Type-C Connector Class Port Mapping Utility
   4  *
   5  * Copyright (C) 2021, Intel Corporation
   6  * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
   7  */
   8
   9 #include <linux/acpi.h>
  10 #include <linux/component.h>
  11 #include <linux/usb.h>
  12
  13 #include "class.h"
  14
  15 static int typec_aggregate_bind(struct device *dev)
  16 {
  17         struct typec_port *port = to_typec_port(dev);
  18
  19         return component_bind_all(dev, &port->con);
  20 }
  21
  22 static void typec_aggregate_unbind(struct device *dev)
  23 {
  24         struct typec_port *port = to_typec_port(dev);
  25
  26         component_unbind_all(dev, &port->con);
  27 }
  28
  29 static const struct component_master_ops typec_aggregate_ops = {
  30         .bind = typec_aggregate_bind,
  31         .unbind = typec_aggregate_unbind,
  32 };
  33
  34 struct each_port_arg {
  35         struct typec_port *port;
  36         struct component_match *match;
  37 };
  38
  39 static int typec_port_compare(struct device *dev, void *fwnode)
  40 {
  41         return device_match_fwnode(dev, fwnode);
  42 }
  43
  44 static int typec_port_match(struct device *dev, void *data)
  45 {
  46         struct acpi_device *adev = to_acpi_device(dev);
  47         struct each_port_arg *arg = data;
  48         struct acpi_device *con_adev;
  49
  50         con_adev = ACPI_COMPANION(&arg->port->dev);
  51         if (con_adev == adev)
  52                 return 0;
  53
  54         if (con_adev->pld_crc == adev->pld_crc)
  55                 component_match_add(&arg->port->dev, &arg->match, typec_port_compare,
  56                                     acpi_fwnode_handle(adev));
  57         return 0;
  58 }
  59
  60 int typec_link_ports(struct typec_port *con)
  61 {
  62         struct each_port_arg arg = { .port = con, .match = NULL };
  63
  64         if (!has_acpi_companion(&con->dev))
  65                 return 0;
  66
  67         acpi_bus_for_each_dev(typec_port_match, &arg);
  68         if (!arg.match)
  69                 return 0;
  70
  71         /*
  72          * REVISIT: Now each connector can have only a single component master.
  73          * So far only the USB ports connected to the USB Type-C connector share
  74          * the _PLD with it, but if there one day is something else (like maybe
  75          * the DisplayPort ACPI device object) that also shares the _PLD with
  76          * the connector, every one of those needs to have its own component
  77          * master, because each different type of component needs to be bind to
  78          * the connector independently of the other components. That requires
  79          * improvements to the component framework. Right now you can only have
  80          * one master per device.
  81          */
  82         return component_master_add_with_match(&con->dev, &typec_aggregate_ops, arg.match);
  83 }
  84
  85 void typec_unlink_ports(struct typec_port *con)
  86 {
  87         if (has_acpi_companion(&con->dev))
  88                 component_master_del(&con->dev, &typec_aggregate_ops);
  89 }