On 2018-04-26 16:08, Michal Simek wrote:
Hi,
this series is trying to address discussion I had with Alan in past
https://patchwork.kernel.org/patch/9738445/.
It is moving uart_register_driver() to probe function like it is done
in
pl011 driver.
And also introducing new function for alias compatibility checking to
resolve cases where some IPs have alias and some of them not.
This case is detected in pl011_probe_dt_alias() but not properly
solved.
Also keep status of free ids/minor numbers in bitmap to know what's the
next unallocated number.
The same solution can be used in pl011, uart16550 and uartlite to
really
get unified kernel.
Tested on these use cases:
Notes:
ff000000 is the first PS uart listed in dtsi
ff010000 is the second PS uart listed in dtsi
Standard zcu102 setting
serial0 = &uart0;
serial1 = &uart1;
[ 0.196628] ff000000.serial: ttyPS0 at MMIO 0xff000000 (irq = 33,
base_baud = 6250000) is a xuartps
[ 0.642542] ff010000.serial: ttyPS1 at MMIO 0xff010000 (irq = 34,
base_baud = 6250000) is a xuartps
Swapped zcu102 setting
serial0 = &uart1;
serial1 = &uart0;
[ 0.196472] ff000000.serial: ttyPS1 at MMIO 0xff000000 (irq = 33,
base_baud = 6250000) is a xuartps
[ 0.196824] ff010000.serial: ttyPS0 at MMIO 0xff010000 (irq = 34,
base_baud = 6250000) is a xuartps
uart0 on alias higher then MAX uart ports
serial0 = &uart1;
serial200 = &uart0;
[ 0.176793] ff000000.serial: ttyPS200 at MMIO 0xff000000 (irq = 33,
base_baud = 6250000) is a xuartps
[ 0.177288] ff010000.serial: ttyPS0 at MMIO 0xff010000 (irq = 34,
base_baud = 6250000) is a xuartps
Both uarts on higher aliases
serial1 = &uart1;
serial2 = &uart0;
[ 0.196470] ff000000.serial: ttyPS2 at MMIO 0xff000000 (irq = 33,
base_baud = 6250000) is a xuartps
[ 0.196823] ff010000.serial: ttyPS1 at MMIO 0xff010000 (irq = 34,
base_baud = 6250000) is a xuartps
uart0 not listed but it is probed first that's why should be ttyPS0 but
there is uart1 via alias
serial0 = &uart1;
[ 0.176656] xuartps ff000000.serial: No serial alias passed. Using
the first free id
[ 0.176671] xuartps ff000000.serial: Validate id 0
[ 0.176680] xuartps ff000000.serial: The empty id is 0
[ 0.176692] xuartps ff000000.serial: ID 0 already taken - skipped
[ 0.176701] xuartps ff000000.serial: Validate id 1
[ 0.176710] xuartps ff000000.serial: The empty id is 1
[ 0.176719] xuartps ff000000.serial: Selected ID 1 allocation passed
[ 0.176760] ff000000.serial: ttyPS1 at MMIO 0xff000000 (irq = 33,
base_baud = 6250000) is a xuartps
[ 0.177104] ff010000.serial: ttyPS0 at MMIO 0xff010000 (irq = 34,
base_baud = 6250000) is a xuartps
uart0 not listed but it is probed first that's why should be ttyPS0
serial1 = &uart1;
[ 0.176661] xuartps ff000000.serial: No serial alias passed. Using
the first free id
[ 0.176676] xuartps ff000000.serial: Validate id 0
[ 0.176686] xuartps ff000000.serial: The empty id is 0
[ 0.176696] xuartps ff000000.serial: Selected ID 0 allocation passed
[ 0.176737] ff000000.serial: ttyPS0 at MMIO 0xff000000 (irq = 33,
base_baud = 6250000) is a xuartps
[ 0.177069] ff010000.serial: ttyPS1 at MMIO 0xff010000 (irq = 34,
base_baud = 6250000) is a xuartps
uarts not listed in aliases list
[ 0.176673] xuartps ff000000.serial: No serial alias passed. Using
the first free id
[ 0.176687] xuartps ff000000.serial: Validate id 0
[ 0.176697] xuartps ff000000.serial: The empty id is 0
[ 0.176707] xuartps ff000000.serial: Selected ID 0 allocation passed
[ 0.176746] ff000000.serial: ttyPS0 at MMIO 0xff000000 (irq = 33,
base_baud = 6250000) is a xuartps
[ 0.177057] xuartps ff010000.serial: No serial alias passed. Using
the first free id
[ 0.177070] xuartps ff010000.serial: Validate id 0
[ 0.177079] xuartps ff010000.serial: The empty id is 0
[ 0.177089] xuartps ff010000.serial: Selected ID 0 allocation failed
[ 0.177098] xuartps ff010000.serial: Validate id 1
[ 0.177107] xuartps ff010000.serial: The empty id is 1
[ 0.177116] xuartps ff010000.serial: Selected ID 1 allocation passed
[ 0.177149] ff010000.serial: ttyPS1 at MMIO 0xff010000 (irq = 34,
base_baud = 6250000) is a xuartps
Thanks,
Michal
Hello Michal,
How will this interact with ns16550 based UARTs?
Can we have both /dev/ttyS0 and /dev/ttyPS0?
Currently we can't unless we create *no* serialN alias for the ns16550.
And there is no other means to lock the /dev/ttySx name to a device
either.
Or will the xuartps driver eventually use /dev/ttySx as well?
Maarten
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