diff options
Diffstat (limited to 'src/devices/device.c')
| -rw-r--r-- | src/devices/device.c | 76 |
1 files changed, 52 insertions, 24 deletions
diff --git a/src/devices/device.c b/src/devices/device.c index 033f41d2ca..87e627d52c 100644 --- a/src/devices/device.c +++ b/src/devices/device.c @@ -376,13 +376,14 @@ static void allocate_vga_resource(void) struct bus *bus; bus = 0; vga = 0; - for(dev = all_devices; dev; dev = dev->next) { + for (dev = all_devices; dev; dev = dev->next) { if (((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY) && - ((dev->class >> 8) != PCI_CLASS_DISPLAY_OTHER)) - { + ((dev->class >> 8) != PCI_CLASS_DISPLAY_OTHER)) { if (!vga) { printk_debug("Allocating VGA resource %s\n", - dev_path(dev)); + dev_path(dev)); + printk_debug("parent of the vga device %s\n", + dev_path(dev->bus->dev)); vga = dev; } if (vga == dev) { @@ -398,19 +399,28 @@ static void allocate_vga_resource(void) bus = vga->bus; } /* Now walk up the bridges setting the VGA enable */ - while(bus) { + while (bus) { + printk_info("Enabling VGA forward on bus connect to %s\n", + dev_path(bus->dev)); bus->bridge_ctrl |= PCI_BRIDGE_CTL_VGA; bus = (bus == bus->dev->bus)? 0 : bus->dev->bus; } } -/** Assign the computed resources to the bridges and devices on the bus. - * Recurse to any bridges found on this bus first. Then do the devices - * on this bus. - * +/** + * @brief Assign the computed resources to the devices on the bus. + * * @param bus Pointer to the structure for this bus - */ + * + * Use the device specific set_resources method to store the computed + * resources to hardware. For bridge devices, the set_resources() method + * has to recurse into every down stream buses. + * + * Mutual recursion: + * assign_resources() -> device_operation::set_resources() + * device_operation::set_resources() -> assign_resources() + */ void assign_resources(struct bus *bus) { struct device *curdev; @@ -418,7 +428,7 @@ void assign_resources(struct bus *bus) printk_spew("%s assign_resources, bus %d link: %d\n", dev_path(bus->dev), bus->secondary, bus->link); - for(curdev = bus->children; curdev; curdev = curdev->sibling) { + for (curdev = bus->children; curdev; curdev = curdev->sibling) { if (!curdev->enabled || !curdev->resources) { continue; } @@ -443,10 +453,13 @@ void assign_resources(struct bus *bus) * * The parent's resources should be enabled first to avoid having enabling * order problem. This is done by calling the parent's enable_resources() - * method and let that method to call it's children's enable_resoruces() via - * enable_childrens_resources(). + * method and let that method to call it's children's enable_resoruces() + * method via the (global) enable_childrens_resources(). * * Indirect mutual recursion: + * enable_resources() -> device_operations::enable_resource() + * device_operations::enable_resource() -> enable_children_resources() + * enable_children_resources() -> enable_resources() */ void enable_resources(struct device *dev) { @@ -461,16 +474,25 @@ void enable_resources(struct device *dev) } /** - * @brief Determine the existence of dynamic devices and construct dynamic + * @brief Determine the existence of devices and extend the device tree. + * + * Most of the devices in the system are listed in the mainboard Config.lb + * file. The device structures for these devices are generated at compile + * time by the config tool and are organized into the device tree. This + * function determines if the devices created at compile time actually exist + * in the physical system. + * + * For devices in the physical system but not listed in the Config.lb file, + * the device structures have to be created at run time and attached to the * device tree. * - * Start from the root device 'dev_root', scan the buses in the system - * recursively, build the dynamic device tree according to the result - * of the probe. + * This function starts from the root device 'dev_root', scan the buses in + * the system recursively, modify the device tree according to the result of + * the probe. * * This function has no idea how to scan and probe buses and devices at all. * It depends on the bus/device specific scan_bus() method to do it. The - * scan_bus() function also has to create the device structure and attach + * scan_bus() method also has to create the device structure and attach * it to the device tree. */ void dev_enumerate(void) @@ -490,12 +512,13 @@ void dev_enumerate(void) printk_info("done\n"); } - /** * @brief Configure devices on the devices tree. * - * Starting at the root of the dynamic device tree, travel recursively, - * and compute resources needed by each device and allocate them. + * Starting at the root of the device tree, travel it recursively in two + * passes. In the first pass, we compute and allocate resources (ranges) + * requried by each device. In the second pass, the resources ranges are + * relocated to their final position and stored to the hardware. * * I/O resources start at DEVICE_IO_START and grow upward. MEM resources start * at DEVICE_MEM_START and grow downward. @@ -519,7 +542,10 @@ void dev_configure(void) printk_err("dev_root missing set_resources\n"); return; } + + printk_info("Reading resources...\n"); root->ops->read_resources(root); + printk_info("Done\n"); /* Get the resources */ io = &root->resource[0]; @@ -539,8 +565,9 @@ void dev_configure(void) allocate_vga_resource(); /* Store the computed resource allocations into device registers ... */ + printk_info("Setting resources...\n"); root->ops->set_resources(root); - + printk_info("Done\n"); #if 0 mem->flags |= IORESOURCE_STORED; report_resource_stored(root, mem, ""); @@ -569,14 +596,15 @@ void dev_enable(void) * @brief Initialize all devices in the global device list. * * Starting at the first device on the global device link list, - * walk the list and call a driver to do device specific setup. + * walk the list and call the device's init() method to do deivce + * specific setup. */ void dev_initialize(void) { struct device *dev; printk_info("Initializing devices...\n"); - for(dev = all_devices; dev; dev = dev->next) { + for (dev = all_devices; dev; dev = dev->next) { if (dev->enabled && !dev->initialized && dev->ops && dev->ops->init) { |