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Diffstat (limited to 'src/devices/root_device.c')
-rw-r--r--src/devices/root_device.c81
1 files changed, 43 insertions, 38 deletions
diff --git a/src/devices/root_device.c b/src/devices/root_device.c
index 897a5a3bbf..a02fe7a060 100644
--- a/src/devices/root_device.c
+++ b/src/devices/root_device.c
@@ -35,7 +35,8 @@ void root_dev_read_resources(device_t root)
}
/**
- * Write the resources for the root device,
+ * @brief Write the resources for the root device
+ *
* and every device under it which are all of the devices.
* @param root Pointer to the device structure for the system root device
*/
@@ -44,10 +45,10 @@ void root_dev_set_resources(device_t root)
struct bus *bus;
bus = &root->link[0];
- compute_allocate_resource(bus,
- &root->resource[0], IORESOURCE_IO, IORESOURCE_IO);
- compute_allocate_resource(bus,
- &root->resource[1], IORESOURCE_MEM, IORESOURCE_MEM);
+ compute_allocate_resource(bus, &root->resource[0],
+ IORESOURCE_IO, IORESOURCE_IO);
+ compute_allocate_resource(bus, &root->resource[1],
+ IORESOURCE_MEM, IORESOURCE_MEM);
assign_resources(bus);
}
@@ -56,26 +57,32 @@ void root_dev_set_resources(device_t root)
*
* The enumeration of certain buses is purely static. The existence of
* devices on those buses can be completely determined at compile time
- * by the config file. Typical expamles are the 'PNP' devices on a legacy
- * ISA/LPC bus. There is no need of probing of any kind, the only thing
- * we have to do is to walk through the bus and enable or disable devices
- * as indicated in the config file.
+ * and is specified in the config file. Typical exapmles are the 'PNP'
+ * devices on a legacy ISA/LPC bus. There is no need of probing of any
+ * kind, the only thing we have to do is to walk through the bus and
+ * enable or disable devices as indicated in the config file.
*
- * This function is the default scan_bus() method for LPC bridges.
+ * On the other hand, some devices are virtual and their existence is
+ * artificial. They can not be probed at run time. One example is the
+ * debug device. Those virtual devices have to be listed in the config
+ * file under some static bus in order to be enumerated at run time.
*
- * @param root Pointer to the device structure for the system root device
- * @param max Maximum bus number allowed in the system.
- * @return Largest bus number used.
+ * This function is the default scan_bus() method for the root device and
+ * LPC bridges.
+ *
+ * @param root Pointer to the root device which the static buses are attached
+ * @param max Maximum bus number currently used before scanning.
+ * @return Largest bus number used after scanning.
*/
-unsigned int scan_static_bus(device_t bus, unsigned int max)
+unsigned int scan_static_bus(device_t root, unsigned int max)
{
device_t child;
unsigned link;
-
- printk_spew("%s for %s\n", __func__, dev_path(bus));
- for(link = 0; link < bus->links; link++) {
- for(child = bus->link[link].children; child; child = child->sibling) {
+ printk_spew("%s for %s\n", __func__, dev_path(root));
+
+ for (link = 0; link < root->links; link++) {
+ for (child = root->link[link].children; child; child = child->sibling) {
if (child->chip_ops && child->chip_ops->enable_dev) {
child->chip_ops->enable_dev(child);
}
@@ -87,8 +94,8 @@ unsigned int scan_static_bus(device_t bus, unsigned int max)
child->enabled?"enabled": "disabled");
}
}
- for(link = 0; link < bus->links; link++) {
- for(child = bus->link[link].children; child; child = child->sibling) {
+ for (link = 0; link < root->links; link++) {
+ for (child = root->link[link].children; child; child = child->sibling) {
if (!child->ops || !child->ops->scan_bus)
continue;
printk_spew("%s scanning...\n", dev_path(child));
@@ -96,7 +103,7 @@ unsigned int scan_static_bus(device_t bus, unsigned int max)
}
}
- printk_spew("%s done\n", __func__);
+ printk_spew("%s for %s done\n", __func__, dev_path(root));
return max;
}
@@ -106,17 +113,20 @@ unsigned int scan_static_bus(device_t bus, unsigned int max)
*
* @param dev the device whos children's resources are to be enabled
*
- * This function is call by the enable_resource() indirectly via the
- * enable_resources() method of devices.
+ * This function is call by the global enable_resources() indirectly via the
+ * device_operation::enable_resources() method of devices.
*
* Indirect mutual recursion:
+ * enable_childrens_resources() -> enable_resources()
+ * enable_resources() -> device_operation::enable_resources()
+ * device_operation::enable_resources() -> enable_children_resources()
*/
void enable_childrens_resources(device_t dev)
{
unsigned link;
- for(link = 0; link < dev->links; link++) {
+ for (link = 0; link < dev->links; link++) {
device_t child;
- for(child = dev->link[link].children; child; child = child->sibling) {
+ for (child = dev->link[link].children; child; child = child->sibling) {
enable_resources(child);
}
}
@@ -131,12 +141,9 @@ void root_dev_enable_resources(device_t dev)
* @brief Scan root bus for generic systems
*
* @param root The root device structure
- * @param max The current bus number scanned so fat, usually 0x00
+ * @param max The current bus number scanned so far, usually 0x00
*
- * This function is the default scan_bus() method of the dynamic root device.
- * The bus heirachy is rooted at the host/northbridge. The northbridge of a
- * generic PCI bus system is at Bus 0, Dev 0, Fun 0 so we scan the whole PCI
- * buses from there.
+ * This function is the default scan_bus() method of the root device.
*/
unsigned int root_dev_scan_bus(device_t root, unsigned int max)
{
@@ -150,11 +157,9 @@ void root_dev_init(device_t root)
/**
* @brief Default device operation for root device
*
- * This is the default device operation for root devices in PCI based systems.
- * These operations should be fully usable as is. However the
- * chip_operations::dev_enable of a motherboard can override this if you
- * want non-default behavior. Currently src/mainboard/arima/hdama/mainbaord.c
- * does this for debugging purposes.
+ * This is the default device operation for root devices. These operations
+ * should be fully usable as is. However the chip_operations::enable_dev()
+ * of a motherboard can override this if you want non-default behavior.
*/
struct device_operations default_dev_ops_root = {
.read_resources = root_dev_read_resources,
@@ -165,9 +170,9 @@ struct device_operations default_dev_ops_root = {
};
/**
- * @brief The root of dynamic device tree.
+ * @brief The root of device tree.
*
- * This is the root of the dynamic device tree. A PCI tree always has
- * one bus, bus 0. Bus 0 contains devices and bridges.
+ * This is the root of the device tree. The device tree is defined in the
+ * static.c file and is generated by config tool during compile time.
*/
extern struct device dev_root;