xref: /openbmc/linux/drivers/usb/typec/port-mapper.c (revision 3c36fe93)
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 
12 #include "class.h"
13 
typec_aggregate_bind(struct device * dev)14 static int typec_aggregate_bind(struct device *dev)
15 {
16 	return component_bind_all(dev, NULL);
17 }
18 
typec_aggregate_unbind(struct device * dev)19 static void typec_aggregate_unbind(struct device *dev)
20 {
21 	component_unbind_all(dev, NULL);
22 }
23 
24 static const struct component_master_ops typec_aggregate_ops = {
25 	.bind = typec_aggregate_bind,
26 	.unbind = typec_aggregate_unbind,
27 };
28 
29 struct each_port_arg {
30 	struct typec_port *port;
31 	struct component_match *match;
32 };
33 
typec_port_compare(struct device * dev,void * fwnode)34 static int typec_port_compare(struct device *dev, void *fwnode)
35 {
36 	return device_match_fwnode(dev, fwnode);
37 }
38 
typec_port_match(struct device * dev,void * data)39 static int typec_port_match(struct device *dev, void *data)
40 {
41 	struct acpi_device *adev = to_acpi_device(dev);
42 	struct each_port_arg *arg = data;
43 	struct acpi_device *con_adev;
44 
45 	con_adev = ACPI_COMPANION(&arg->port->dev);
46 	if (con_adev == adev)
47 		return 0;
48 
49 	if (con_adev->pld_crc == adev->pld_crc)
50 		component_match_add(&arg->port->dev, &arg->match, typec_port_compare,
51 				    acpi_fwnode_handle(adev));
52 	return 0;
53 }
54 
typec_link_ports(struct typec_port * con)55 int typec_link_ports(struct typec_port *con)
56 {
57 	struct each_port_arg arg = { .port = con, .match = NULL };
58 
59 	if (!has_acpi_companion(&con->dev))
60 		return 0;
61 
62 	acpi_bus_for_each_dev(typec_port_match, &arg);
63 	if (!arg.match)
64 		return 0;
65 
66 	/*
67 	 * REVISIT: Now each connector can have only a single component master.
68 	 * So far only the USB ports connected to the USB Type-C connector share
69 	 * the _PLD with it, but if there one day is something else (like maybe
70 	 * the DisplayPort ACPI device object) that also shares the _PLD with
71 	 * the connector, every one of those needs to have its own component
72 	 * master, because each different type of component needs to be bind to
73 	 * the connector independently of the other components. That requires
74 	 * improvements to the component framework. Right now you can only have
75 	 * one master per device.
76 	 */
77 	return component_master_add_with_match(&con->dev, &typec_aggregate_ops, arg.match);
78 }
79 
typec_unlink_ports(struct typec_port * con)80 void typec_unlink_ports(struct typec_port *con)
81 {
82 	if (has_acpi_companion(&con->dev))
83 		component_master_del(&con->dev, &typec_aggregate_ops);
84 }
85