src/acpi/acpigen_usb.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2
   3 #include <acpi/acpi.h>
   4 #include <acpi/acpi_device.h>
   5 #include <acpi/acpigen.h>
   6 #include <acpi/acpigen_usb.h>
   7
   8 static const char *power_role_to_str(enum usb_typec_power_role power_role)
   9 {
  10         switch (power_role) {
  11         case TYPEC_POWER_ROLE_SOURCE:
  12                 return "source";
  13         case TYPEC_POWER_ROLE_SINK:
  14                 return "sink";
  15         case TYPEC_POWER_ROLE_DUAL:
  16                 return "dual";
  17         default:
  18                 return "unknown";
  19         }
  20 }
  21
  22 static const char *try_power_role_to_str(enum usb_typec_try_power_role try_power_role)
  23 {
  24         switch (try_power_role) {
  25         case TYPEC_TRY_POWER_ROLE_NONE:
  26                 /*
  27                  * This should never get returned; if there is no try-power role for a device,
  28                  * then the try-power-role field is not added to the DSD. Thus, this is just
  29                  * for completeness.
  30                  */
  31                 return "none";
  32         case TYPEC_TRY_POWER_ROLE_SINK:
  33                 return "sink";
  34         case TYPEC_TRY_POWER_ROLE_SOURCE:
  35                 return "source";
  36         default:
  37                 return "unknown";
  38         }
  39 }
  40
  41 static const char *data_role_to_str(enum usb_typec_data_role data_role)
  42 {
  43         switch (data_role) {
  44         case TYPEC_DATA_ROLE_DFP:
  45                 return "host";
  46         case TYPEC_DATA_ROLE_UFP:
  47                 return "device";
  48         case TYPEC_DATA_ROLE_DUAL:
  49                 return "dual";
  50         default:
  51                 return "unknown";
  52         }
  53 }
  54
  55 /* Add port capabilities as DP properties */
  56 static void add_port_caps(struct acpi_dp *dsd,
  57                           const struct typec_connector_class_config *config)
  58 {
  59         acpi_dp_add_string(dsd, "power-role", power_role_to_str(config->power_role));
  60         acpi_dp_add_string(dsd, "data-role", data_role_to_str(config->data_role));
  61
  62         if (config->try_power_role != TYPEC_TRY_POWER_ROLE_NONE)
  63                 acpi_dp_add_string(dsd, "try-power-role",
  64                                    try_power_role_to_str(config->try_power_role));
  65 }
  66
  67 static void add_device_ref(struct acpi_dp *dsd,
  68                            const char *prop_name,
  69                            const struct device *dev)
  70 {
  71         const char *path;
  72         char *fresh;
  73
  74         if (!dev || !dev->enabled)
  75                 return;
  76
  77         /*
  78          * Unfortunately, the acpi_dp_* API doesn't write out the data immediately, thus we need
  79          * different storage areas for all of the strings, so strdup() is used for that. It is
  80          * safe to use strdup() here, because the strings are generated at build-time and are
  81          * guaranteed to be NUL-terminated (they come from the devicetree).
  82          */
  83         path = acpi_device_path(dev);
  84         if (path) {
  85                 fresh = strdup(path);
  86                 if (fresh)
  87                         acpi_dp_add_reference(dsd, prop_name, fresh);
  88         }
  89 }
  90
  91 static void add_device_references(struct acpi_dp *dsd,
  92                                   const struct typec_connector_class_config *config)
  93 {
  94         /*
  95          * Add references to the USB port objects so that the consumer of this information can
  96          * know whether the port supports USB2, USB3, and/or USB4.
  97          */
  98         add_device_ref(dsd, "usb2-port", config->usb2_port);
  99         add_device_ref(dsd, "usb3-port", config->usb3_port);
 100         add_device_ref(dsd, "usb4-port", config->usb4_port);
 101
 102         /*
 103          * Add references to the ACPI device(s) which control the orientation, USB data role and
 104          * data muxing.
 105          */
 106         add_device_ref(dsd, "orientation-switch", config->orientation_switch);
 107         add_device_ref(dsd, "usb-role-switch", config->usb_role_switch);
 108         add_device_ref(dsd, "mode-switch", config->mode_switch);
 109 }
 110
 111 void acpigen_write_typec_connector(const struct typec_connector_class_config *config,
 112                                    int port_number,
 113                                    add_custom_dsd_property_cb add_custom_dsd_property)
 114 {
 115         struct acpi_dp *dsd;
 116         char name[5];
 117
 118         /* Create a CONx device */
 119         snprintf(name, sizeof(name), "CON%1X", port_number);
 120         acpigen_write_device(name);
 121         acpigen_write_name_integer("_ADR", port_number);
 122
 123         dsd = acpi_dp_new_table("_DSD");
 124
 125         /* Write out the _DSD table */
 126         acpi_dp_add_integer(dsd, "port-number", port_number);
 127         add_port_caps(dsd, config);
 128         add_device_references(dsd, config);
 129
 130         /* Allow client to add custom properties if desired */
 131         if (add_custom_dsd_property)
 132                 add_custom_dsd_property(dsd, port_number);
 133         acpi_dp_write(dsd);
 134
 135         acpigen_pop_len(); /* Device */
 136 }