Thanks for your quick response. Please find my comments below. On Tue, Dec 3, 2013 at 11:09 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: > On Tue, Dec 3, 2013 at 4:24 AM, Jagan Teki <jagannadh.teki@xxxxxxxxx> wrote: >> Hi, >> >> I have few question on Linux PCIe subsystem, I am trying to understand >> the PCIe on ARM platform. >> 1. Compared to PCI, PCIe have an extra port functionalists/services >> which is implemented drivers/pci/pcie/* is it true? > > Yes. > >> 2. PCIe root complex is same as Host controller drivers in linux drivers/host/* > > Yes. > >> 3. As individual endpoint drivers are registered to pci_core as >> pci_driver_register, then what is the common call for registering >> individual HC driver to pci-core? > > The host controller-PCI core interface is not as mature as the > pci_register_driver() interface. The basic interface is > pci_scan_root_bus(). If you skim through the drivers in > drivers/pci/host/* and drivers/acpi/pci_root.c, the interface to the > PCI core will be fairly obvious. And you'll learn what the existing > practices are in case you need to add or modify something. OK. I understand the flow as below - please correct if am wrong. >From low level (hw) - HC driver has a platform registration using platform_driver_register() to lower layer and then pci_scan_root_bus() --> pci_common_init_dev() registration to upper layer as PCI - BIOS and then ends. >From upper level (app) - each endpoint driver has pci_driver_register() call to PCI Core for lower level and then the upper level registration is based on endpoint(). What is the connection here for PCI-BIOS and PCI-Core here, does these are two different entities means there is no common call for these? I see for ARM - "arch/arm/kernel/bios32.c" is PCI-BIOS is it correct? does we have separate BIOS codes for architectures? -- Thanks, Jagan. -------- Jagannadha Sutradharudu Teki, E: jagannadh.teki@xxxxxxxxx, P: +91-9676773388 Engineer - System Software Hacker U-boot - SPI Custodian and Zynq APSOC Ln: http://www.linkedin.com/in/jaganteki -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
