Re: [PATCH v3] tty: serial: don't do termios for BTIF
From: sean.wang
Date: Tue Jun 16 2020 - 23:58:33 EST
From: Sean Wang <sean.wang@xxxxxxxxxxxx>
>>
>> From: Sean Wang <sean.wang@xxxxxxxxxxxx>
>>
>> Bluetooth Interface (BTIF) is designed dedicatedly for MediaTek SOC
>> with BT in order to be instead of the UART interface between BT module
>> and Host CPU, and not exported to user space to access.
>>
>> As the UART design, BTIF will be an APB slave and can transmit or
>> receive data by MCU access, but doesn't provide termios function like
>> baudrate and flow control setup.
>>
>> Even LCR on offset 0xC that is just a FAKELCR a. If FAKELCR[7] is
>> equaled to 1, RBR(0x00), THR(0x00), IER(0x04)
>> will not be readable/writable.
>>
>> b. If FAKELCR is equaled to 0xBF, RBR(0x00), THR(0x00), IER(0x04),
>> IIR(0x08), and LSR(0x14) will not be readable/writable.
>>
>> So adding a new capability 'UART_CAP_NTIO' for the unusual unsupported
>> case.
>>
>> Fixes: 1c16ae65e250 ("serial: 8250: of: Add new port type for MediaTek
>> BTIF controller on MT7622/23 SoC")
>> Cc: Steven Liu <steven.liu@xxxxxxxxxxxx>
>
>> Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
>
>I didn't suggest this change. I only commented on the name of the macro.
my fault. i will remove the tag from next version.
>
>> Signed-off-by: Sean Wang <sean.wang@xxxxxxxxxxxx>
>> Signed-off-by: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
>>
>> --