Re: [PATCH V5 3/3] ARM64 LPC: LPC driver implementation on Hip06
From: Arnd Bergmann <arnd@arndb.de>
Date: 2016-11-09 21:37:26
Also in:
linux-arm-kernel, linux-pci, linux-serial, lkml
From: Arnd Bergmann <arnd@arndb.de>
Date: 2016-11-09 21:37:26
Also in:
linux-arm-kernel, linux-pci, linux-serial, lkml
On Wednesday, November 9, 2016 12:10:43 PM CET Gabriele Paoloni wrote:
quoted
On Tuesday, November 8, 2016 11:47:09 AM CET zhichang.yuan wrote:quoted
+ /* + * The first PCIBIOS_MIN_IO is reserved specifically forindirectIO.quoted
+ * It will separate indirectIO range from pci host bridge to + * avoid the possible PIO conflict. + * Set the indirectIO range directly here. + */ + lpcdev->io_ops.start = 0; + lpcdev->io_ops.end = PCIBIOS_MIN_IO - 1; + lpcdev->io_ops.devpara = lpcdev; + lpcdev->io_ops.pfin = hisilpc_comm_in; + lpcdev->io_ops.pfout = hisilpc_comm_out; + lpcdev->io_ops.pfins = hisilpc_comm_ins; + lpcdev->io_ops.pfouts = hisilpc_comm_outs;I have to look at patch 2 in more detail again, after missing a few review rounds. I'm still a bit skeptical about hardcoding a logical I/O port range here, and would hope that we can just go through the same assignment of logical port ranges that we have for PCI buses, decoupling the bus addresses from the linux-internal ones.The point here is that we want to avoid any conflict/overlap between the LPC I/O space and the PCI I/O space. With the assignment above we make sure that LPC never interfere with PCI I/O space.
But we already abstract the PCI I/O space using dynamic registration. There is no need to hardcode the logical address for ISA, though I think we can hardcode the bus address to start at zero here. Arnd