[PATCH v3] GPIO: Add support for GPIO on CLPS711X-target platform

[Alexander Shiyan]

On Sun, 7 Oct 2012 11:28:03 +0100
Russell King - ARM Linux <linux at arm.linux.org.uk> wrote:

> > ...
> > > > +++ b/arch/arm/mach-clps711x/include/mach/gpio.h
> > > > @@ -0,0 +1,27 @@
> > > > +/*
> > > > + *  This file contains the CLPS711X GPIO definitions.
> > > > + *
> > > > + *  Copyright (C) 2012 Alexander Shiyan <shc_work at mail.ru>
> > > > + *
> > > > + * This program is free software; you can redistribute it and/or modify
> > > > + * it under the terms of the GNU General Public License as published by
> > > > + * the Free Software Foundation; either version 2 of the License, or
> > > > + * (at your option) any later version.
> > > > + */
> > > > +
> > > > +/* Simple helper for convert port & pin to GPIO number */
> > > > +#define CLPS711X_GPIO(port, bit)	((port) * 8 + (bit))
> > > > +
> > > > +/* Temporaty definitions for GPIO-ports */
> > > > +/* Will be removed after remove clps_read(write) macros */
> > > > +#include <mach/hardware.h>
> > > > +#define _PADR	(CLPS711X_VIRT_BASE + PADR)
> > > > +#define _PBDR	(CLPS711X_VIRT_BASE + PBDR)
> > > > +#define _PCDR	(CLPS711X_VIRT_BASE + PCDR)
> > > > +#define _PDDR	(CLPS711X_VIRT_BASE + PDDR)
> > > > +#define _PADDR	(CLPS711X_VIRT_BASE + PADDR)
> > > > +#define _PBDDR	(CLPS711X_VIRT_BASE + PBDDR)
> > > > +#define _PCDDR	(CLPS711X_VIRT_BASE + PCDDR)
> > > > +#define _PDDDR	(CLPS711X_VIRT_BASE + PDDDR)
> > > > +#define _PEDR	(CLPS711X_VIRT_BASE + PEDR)
> > > > +#define _PEDDR	(CLPS711X_VIRT_BASE + PEDDR)
> > > 
> > > Why can't this file (or the bulk of it) live in drivers/gpio ?
> > We should have access for macros in gpio.h from board support files
> > and other drivers. From drivers/gpio it not possible.
> > If you ask about port definitions, as I say before, it will be
> > removed later after rework on platform hardware definitions.
> 
> No other drivers should be directly accessing the GPIO registers -
> doing so is likely a bug because of the inherent lack of locking,
> which will cause race conditions.
> 
> All accesses to GPIOs should be done via gpiolib, even from board
> support files.

Yes, and I am say only about macro that calculate GPIO-number from
port number and bit position. Access to this is a helpful for understand
source code.

-- 
Alexander Shiyan <shc_work at mail.ru>