src/device/root_device.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <console/console.h>
   4 #include <device/device.h>
   5 #include <device/pci.h>
   6 #include <reset.h>
   7
   8 const char mainboard_name[] = CONFIG_MAINBOARD_VENDOR " " CONFIG_MAINBOARD_PART_NUMBER;
   9
  10 void enable_static_device(struct device *dev)
  11 {
  12         if (dev->chip_ops && dev->chip_ops->enable_dev)
  13                 dev->chip_ops->enable_dev(dev);
  14
  15         if (dev->ops && dev->ops->enable)
  16                 dev->ops->enable(dev);
  17
  18         printk(BIOS_DEBUG, "%s %s\n", dev_path(dev),
  19                dev->enabled ? "enabled" : "disabled");
  20 }
  21
  22 /**
  23  * Enable devices on static buses.
  24  *
  25  * The enumeration of certain buses is purely static. The existence of
  26  * devices on those buses can be completely determined at compile time
  27  * and is specified in the config file. Typical examples are the 'PNP'
  28  * devices on a legacy ISA/LPC bus. There is no need of probing of any kind,
  29  * the only thing we have to do is to walk through the bus and
  30  * enable or disable devices as indicated in the config file.
  31  *
  32  * On the other hand, some devices are virtual and their existence is
  33  * artificial. They can not be probed at run time. One example is the
  34  * debug device. Those virtual devices have to be listed in the config
  35  * file under some static bus in order to be enumerated at run time.
  36  *
  37  * @param bus Pointer to the device to which the static buses are attached to.
  38  */
  39
  40 void enable_static_devices(struct device *bus)
  41 {
  42         struct device *child;
  43         struct bus *link;
  44
  45         for (link = bus->link_list; link; link = link->next) {
  46                 for (child = link->children; child; child = child->sibling) {
  47                         enable_static_device(child);
  48                 }
  49         }
  50 }
  51
  52 void scan_generic_bus(struct device *bus)
  53 {
  54         struct device *child;
  55         struct bus *link;
  56         static int bus_max = 0;
  57
  58         printk(BIOS_SPEW, "%s for %s\n", __func__, dev_path(bus));
  59
  60         for (link = bus->link_list; link; link = link->next) {
  61
  62                 link->secondary = ++bus_max;
  63
  64                 for (child = link->children; child; child = child->sibling) {
  65                         enable_static_device(child);
  66                         printk(BIOS_DEBUG, "bus: %s[%d]->", dev_path(child->bus->dev),
  67                                child->bus->link_num);
  68                 }
  69         }
  70
  71         printk(BIOS_SPEW, "%s for %s done\n", __func__, dev_path(bus));
  72 }
  73
  74 void scan_smbus(struct device *bus)
  75 {
  76         scan_generic_bus(bus);
  77 }
  78
  79 /*
  80  * Default scan_bus() implementation
  81  *
  82  * This is the default implementation for buses that can't
  83  * be probed at runtime. It simply walks through the topology
  84  * given by the mainboard's `devicetree.cb`.
  85  *
  86  * First, all direct descendants of the given device are
  87  * enabled. Then, downstream buses are scanned.
  88  */
  89 void scan_static_bus(struct device *bus)
  90 {
  91         struct bus *link;
  92
  93         printk(BIOS_SPEW, "%s for %s\n", __func__, dev_path(bus));
  94
  95         enable_static_devices(bus);
  96
  97         for (link = bus->link_list; link; link = link->next)
  98                 scan_bridges(link);
  99
 100         printk(BIOS_SPEW, "%s for %s done\n", __func__, dev_path(bus));
 101 }
 102
 103 static void root_dev_reset(struct bus *bus)
 104 {
 105         printk(BIOS_INFO, "Resetting board...\n");
 106         board_reset();
 107 }
 108
 109 #if CONFIG(HAVE_ACPI_TABLES)
 110 static const char *root_dev_acpi_name(const struct device *dev)
 111 {
 112         return "\\_SB";
 113 }
 114 #endif
 115
 116 /**
 117  * Default device operation for root device.
 118  *
 119  * This is the default device operation for root devices. These operations
 120  * should be fully usable as is. However the chip_operations::enable_dev()
 121  * of a motherboard can override this if you want non-default behavior.
 122  */
 123 struct device_operations default_dev_ops_root = {
 124         .read_resources   = noop_read_resources,
 125         .set_resources    = noop_set_resources,
 126         .scan_bus         = scan_static_bus,
 127         .reset_bus        = root_dev_reset,
 128 #if CONFIG(HAVE_ACPI_TABLES)
 129         .acpi_name        = root_dev_acpi_name,
 130 #endif
 131 };