exact same (subsystem) device and vendor IDs. However, the reference
design for the OXu16PCI954 uses a 14.7456 MHz clock (as does the EXSYS
EX-41098-2 equipped with these), while at least the OX16PCI954 defaults
to a 1.8432 MHz one. According to the datasheets of these chips, the
only difference in PCI configuration space is that OXu16PCI954 have
a revision ID of 1 while the other two are at 0. So employ the latter
for determining the default clock rates of this family.
Note that one might think that the actual clock could be derived from
the Clock Prescaler Register (CPR) of these chips. Unfortunately, this
is not that case and its use and content are orthogonal to the frequency
of the crystal employed.
Tested with an EXSYS EX-41098-2, which identifies and attaches as:
pcib4@pci0:19:0:0: class=0x060400 card=0x02dd1014 chip=0x10801b21
rev=0x03 hdr=0x01
vendor = 'ASMedia Technology Inc.'
device = 'ASM1083/1085 PCIe to PCI Bridge'
class = bridge
subclass = PCI-PCI
puc0@pci0:20:4:0: class=0x070006 card=0x00001415 chip=0x95011415
rev=0x01 hdr=0x00
vendor = 'Oxford Semiconductor Ltd'
device = 'OX16PCI954 (Quad 16950 UART) function 0 (Uart)'
class = simple comms
subclass = UART
puc1@pci0:20:4:1: class=0x068000 card=0x00001415 chip=0x95111415
rev=0x01 hdr=0x00
vendor = 'Oxford Semiconductor Ltd'
device = 'OX16PCI954 (Quad 16950 UART) function 1 (8bit bus)'
class = bridge
puc2@pci0:20:8:0: class=0x070006 card=0x00001415 chip=0x95011415
rev=0x01 hdr=0x00
vendor = 'Oxford Semiconductor Ltd'
device = 'OX16PCI954 (Quad 16950 UART) function 0 (Uart)'
class = simple comms
subclass = UART
puc3@pci0:20:8:1: class=0x068000 card=0x00001415 chip=0x95111415
rev=0x01 hdr=0x00
vendor = 'Oxford Semiconductor Ltd'
device = 'OX16PCI954 (Quad 16950 UART) function 1 (8bit bus)'
class = bridge
pci20: <ACPI PCI bus> on pcib4
puc0: <Oxford Semiconductor OX16PCI954 UARTs> port 0x5000-0x501f,
0x5020-0x503f mem 0xc6000000-0xc6000fff,0xc6001000-0xc6001fff irq 16 at
device 4.0 on pci20
uart1: <16950 or compatible> at port 1 on puc0
uart2: <16950 or compatible> at port 2 on puc0
uart3: <16950 or compatible> at port 3 on puc0
uart4: <16950 or compatible> at port 4 on puc0
puc1: <Oxford Semiconductor OX9160/OX16PCI954 UARTs (function 1)> port
0x5040-0x505f,0x5060-0x507f mem 0xc6002000-0xc6002fff,0xc6003000-0xc6003fff
irq 16 at device 4.1 on pci20
puc2: <Oxford Semiconductor OX16PCI954 UARTs> port 0x5080-0x509f,
0x50a0-0x50bf mem 0xc6004000-0xc6004fff,0xc6005000-0xc6005fff irq 16 at
device 8.0 on pci20
uart5: <16950 or compatible> at port 1 on puc2
uart6: <16950 or compatible> at port 2 on puc2
uart7: <16950 or compatible> at port 3 on puc2
uart8: <16950 or compatible> at port 4 on puc2
puc3: <Oxford Semiconductor OX9160/OX16PCI954 UARTs (function 1)> port
0x50c0-0x50df,0x50e0-0x50ff mem 0xc6006000-0xc6006fff,0xc6007000-0xc6007fff
irq 16 at device 8.1 on pci20
MFC after: 2 weeks
d5e0798e6d