[PATCH 10/12] tty: amba-pl011: add support for 32-bit register access

Timur Tabi timur at codeaurora.org
Mon Nov 16 12:52:00 PST 2015

On 11/16/2015 12:30 PM, Russell King - ARM Linux wrote:
> We_could_  augment include/uapi/linux/serial.h and
> include/linux/serial_core.h to add a 16-bit LE MMIO accessor identifier,
> but hacking it by deciding to re-use SERIAL_IO_PORT for something it
> isn't is abhorrent to me.

I don't want to belabor this, because there's nothing wrong with your 
patch.  I can understand that we shouldn't be mis-using a variable, but 
I don't understand how this is a misuse of SERIAL_IO_PORT.

We could do something like:

#define UPIO_PORT               (SERIAL_IO_PORT)
#define UPIO_HUB6               (SERIAL_IO_HUB6)
#define UPIO_MEM                (SERIAL_IO_MEM)		// 8-bit
#define UPIO_MEM32              (SERIAL_IO_MEM32)   	// 32-bit
#define UPIO_AU                 (SERIAL_IO_AU)
#define UPIO_TSI                (SERIAL_IO_TSI)
#define UPIO_MEM32BE            (SERIAL_IO_MEM32BE)
#define UPIO_MEMx		(SERIAL_IO_MEMx)	// any bit

uap->port.iotype = vendor->access_32b ? UPIO_MEM32 : UPIO_MEMx;

Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.

More information about the linux-arm-kernel mailing list