Get USB Host Controller parameters in Linux programmatically - c

Question

I need to get some parameters related to USB Host Controllers in Linux. I made a lot of searches in the internet and the only way that I found is using pciutils lib. Each PCI device is in the structure pci_dev in pci.h:
struct pci_dev {
struct pci_dev *next; /* Next device in the chain */
u16 domain_16; /* 16-bit version of the PCI domain for backward compatibility */
/* 0xffff if the real domain doesn't fit in 16 bits */
u8 bus, dev, func; /* Bus inside domain, device and function */
/* These fields are set by pci_fill_info() */
int known_fields; /* Set of info fields already known */
u16 vendor_id, device_id; /* Identity of the device */
u16 device_class; /* PCI device class */
int irq; /* IRQ number */
pciaddr_t base_addr[6]; /* Base addresses including flags in lower bits */
pciaddr_t size[6]; /* Region sizes */
pciaddr_t rom_base_addr; /* Expansion ROM base address */
pciaddr_t rom_size; /* Expansion ROM size */
struct pci_cap *first_cap; /* List of capabilities */
char *phy_slot; /* Physical slot */
char *module_alias; /* Linux kernel module alias */
char *label; /* Device name as exported by BIOS */
int numa_node; /* NUMA node */
pciaddr_t flags[6]; /* PCI_IORESOURCE_* flags for regions */
pciaddr_t rom_flags; /* PCI_IORESOURCE_* flags for expansion ROM */
int domain; /* PCI domain (host bridge) */
/* Fields used internally */
struct pci_access *access;
struct pci_methods *methods;
u8 *cache; /* Cached config registers */
int cache_len;
int hdrtype; /* Cached low 7 bits of header type, -1 if unknown */
void *aux; /* Auxiliary data */
struct pci_property *properties; /* A linked list of extra properties */
struct pci_cap *last_cap; /* Last capability in the list */
};
I found also that I can parse pci devices as following:
struct pci_access *pacc1;
struct pci_dev *dev1;
unsigned int c1;
char namebuf1[1024], *name1;
pacc1 = pci_alloc(); /* Get the pci_access structure */
/* Set all options you want -- here we stick with the defaults */
pci_init(pacc1); /* Initialize the PCI library */
pci_scan_bus(pacc1); /* We want to get the list of devices */
for (dev1=pacc1->devices; dev1; dev1=dev1->next) /* Iterate over all devices */
{
pci_fill_info(dev1, PCI_FILL_IDENT | PCI_FILL_BASES | PCI_FILL_CLASS); /* Fill in header info we need */
c1 = pci_read_byte(dev1, PCI_INTERRUPT_PIN); /* Read config register directly */
printf("%04x:%02x:%02x.%d vendor=%04x device=%04x class=%04x irq=%d (pin %d) base0=%lx",
dev1->domain, dev1->bus, dev1->dev, dev1->func, dev1->vendor_id, dev1->device_id,
dev1->device_class, dev1->irq, c1, (long) dev1->base_addr[0]);
/* Look up and print the full name of the device */
name1 = pci_lookup_name(pacc, namebuf1, sizeof(namebuf1), PCI_LOOKUP_DEVICE, dev1->vendor_id, dev1->device_id);
printf(" ***************** %d: (%s)\n", dev1->dev, name1);
}
pci_cleanup(pacc1); /* Close everything */
Is there a way to check in the loop if the corresponding pci device corresponds to an USB Host Controller? Or is there a simpler way to get USB Host Controller infos?