Re: [PATCH] PCI: keystone: update to support multiple pci ports
From: Murali Karicheri
Date: Fri Sep 05 2014 - 16:37:45 EST
On 09/05/2014 03:00 PM, Arnd Bergmann wrote:
On Friday 05 September 2014 14:33:54 Murali Karicheri wrote:
This looks like it's a shared register of some sort that doesn't
really belong into the registers of a particular port. Could it
be that it's actually for the PHY?
This a shared device configuration register between the two ports the
desciption states it is bootstrap configuration of the PCIe module as
Endpoint or Root complex and Not Phy. Hope below text will help.
Ok. Why do you want to have this user-selectable though? Can't it
just be set by the boot loader before starting Linux?
Arnd,
As the driver is responsible for configuring the device to support the
device functionality, it make sense to do this in the device driver. The
driver enables clock to the IP and this is an addition thing to be
configured so that when the device is powered up, it should function as
RC. The IP can be configured to work as Root Complex or Endpoint. So not
sure why you want to me to move this functionality to boot loader.
Murali
Arnd
Table 3-23 Device Configuration Register (DEVCFG)
PCIESSMODE[1:0] 00b PCIESSMODE is used to control the
functionality of PCIESS module out of
reset. This MMR output is connected to
DEVTYPE input of PCIESS
(Changes from
Nysh) : Note that in Nysh this value came
from a bootstrap pin.
00 : Endpoint
01 : Legacy Endpoint
10 : Rootcomplex
11 : Reserved
PCIESS_1_MODE[1:0
]
00b PCIESSMODE is used to control the
functionality of PCIE_1 module out of
reset. This MMR output is connected to
DEVTYPE input of PCIE_1
00 : Endpoint
01 : Legacy Endpoint
10 : Rootcomplex
11 : Reserv
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