[PATCH 10/12] tty: amba-pl011: add support for 32-bit register access
peter at hurleysoftware.com
Mon Nov 16 13:18:19 PST 2015
On 11/16/2015 01:30 PM, Russell King - ARM Linux wrote:
> 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.
The UPIO_* comments were added recently.
The proliferation of different bitness and endianness implied that
UPIO_MEM was strictly 8-bit, but that's not true and I'll remove the
UPIO_MEM bitness notation from the header.
The uapi header has no such notation and I think the original value and
meaning of UPIO_MEM used by the pl011 driver should remain.
I see no real issue with using different iotype values to describe
the register access method required when other than what the driver
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