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

Russell King - ARM Linux linux at arm.linux.org.uk
Mon Nov 16 10:30:06 PST 2015

On Mon, Nov 16, 2015 at 12:25:45PM -0600, Timur Tabi wrote:
> How is it touching core files?  Granted, we might still need access_32b in
> vendor_data, but not for SBSA, since SBSA already has a mechanism to
> determine what 32-bit is needed or not.
> Then in pl011_probe(), just have:
> 	uap->port.iotype = vendor->access_32b ? UPIO_MEM32 : 0;

That fails my sanity filters, sorry.  iotype takes these values, and
these values only:

#define UPIO_PORT               (SERIAL_IO_PORT)        /* 8b I/O port access */#define UPIO_HUB6               (SERIAL_IO_HUB6)        /* Hub6 ISA card */
#define UPIO_MEM                (SERIAL_IO_MEM)         /* 8b MMIO access */
#define UPIO_MEM32              (SERIAL_IO_MEM32)       /* 32b little endian */
#define UPIO_AU                 (SERIAL_IO_AU)          /* Au1x00 and RT288x type IO */
#define UPIO_TSI                (SERIAL_IO_TSI)         /* Tsi108/109 type IO */#define UPIO_MEM32BE            (SERIAL_IO_MEM32BE)     /* 32b big endian */

These are exposed to userspace, and they have meaning.

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.

FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.

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