[U-Boot] [PATCH 1/2 v4] ARM : Add GPIO Driver and IOMUX definition for S3C2440

Marek Vasut marex at denx.de
Wed May 2 04:44:03 CEST 2012


Dear Minkyu Kang,

> Dear Gabriel Huau,
> 
> On 30 April 2012 23:11, Gabriel Huau <contact at huau-gabriel.fr> wrote:
> > It's now possible to use the gpio driver interface
> > for s3c2440. This patch add iomux definitions too.
> > 
> > Signed-off-by: Gabriel Huau <contact at huau-gabriel.fr>
> > ---
> > Changes for v2:
> >        - Modification of the coding style
> >        - Add my email address to copyright
> >        - Remove a typedef
> >        - Move some defines to driver file
> > 
> > Changes for v3:
> >        - Cleanup coding style
> >        - Changement of the commit message
> > 
> > Changes for v4:
> >        - Add a nice commit message
> > 
> >  arch/arm/include/asm/arch-s3c24x0/gpio.h  |  171
> > ++++++++++++++++++++++++ arch/arm/include/asm/arch-s3c24x0/iomux.h |
> >  200 +++++++++++++++++++++++++++++ drivers/gpio/Makefile                
> >     |    1 +
> >  drivers/gpio/s3c2440_gpio.c               |   94 ++++++++++++++
> >  4 files changed, 466 insertions(+)
> >  create mode 100644 arch/arm/include/asm/arch-s3c24x0/gpio.h
> >  create mode 100644 arch/arm/include/asm/arch-s3c24x0/iomux.h
> >  create mode 100644 drivers/gpio/s3c2440_gpio.c
> > 
> > diff --git a/drivers/gpio/s3c2440_gpio.c b/drivers/gpio/s3c2440_gpio.c
> > new file mode 100644
> > index 0000000..12a9043
> > --- /dev/null
> > +++ b/drivers/gpio/s3c2440_gpio.c
> > @@ -0,0 +1,94 @@
> > +/*
> > + * Copyright (C) 2012
> > + * Gabriel Huau <contact at huau-gabriel.fr>
> > + *
> > + * See file CREDITS for list of people who contributed to this
> > + * project.
> > + *
> > + * 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.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + * GNU General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU General Public License
> > + * along with this program; if not, write to the Free Software
> > + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
> > + * MA 02111-1307 USA
> > + */
> > +#include <common.h>
> > +#include <asm/arch/s3c2440.h>
> > +#include <asm/gpio.h>
> > +#include <asm/io.h>
> > +
> > +#define GPIO_INPUT  0x0
> > +#define GPIO_OUTPUT 0x1
> > +
> > +/* 0x4 means that we want DAT and not CON register */
> > +#define GPIO_PORT(x)   ((((x) >> 5) & 0x3) + 0x4)
> > +#define GPIO_BIT(x)            ((x) & 0x3f)
> > +
> > +/*
> > + * It's how we calculate the full port address
> > + * We have to get the number of the port + 1 (Port A is at 0x56000001
> > ...) + * We move it at the second digit, and finally we add 0x4 because
> > we want + * to modify GPIO DAT and not CON
> > + */
> > +#define GPIO_FULLPORT(x) (S3C24X0_GPIO_BASE | ((GPIO_PORT(gpio) + 1) <<
> > 1)) +
> > +int gpio_set_value(unsigned gpio, int value)
> > +{
> > +       unsigned l = readl(GPIO_FULLPORT(gpio));
> > +       unsigned port = GPIO_FULLPORT(gpio);
> > +
> > +       /*
> > +        * All GPIO Port have a configuration on
> > +        * 2 bits excepted the first GPIO (A) which
> > +        * have only 1 bit of configuration.
> > +        */
> > +       if (value)
> > +               if (!GPIO_PORT(gpio))
> > +                       l |= (0x1 << GPIO_BIT(gpio));
> > +               else
> > +                       l |= (0x3 << GPIO_BIT(gpio));
> > +       else
> > +               if (!GPIO_PORT(gpio))
> > +                       l &= ~(0x1 << GPIO_BIT(gpio));
> > +               else
> > +                       l &= ~(0x3 << GPIO_BIT(gpio));
> 
> Need brace at this if..else statement.

I wanted to ask why, but ... C isn't python, good point ;-)

> > +       return writel(port, l);
> > +}
> > +
> > +int gpio_get_value(unsigned gpio)
> > +{
> > +       unsigned l = readl(GPIO_FULLPORT(gpio));
> > +
> > +       if (GPIO_PORT(gpio) == 0) /* PORT A */
> > +               return (l >> GPIO_BIT(gpio)) & 0x1;
> > +       return (l >> GPIO_BIT(gpio)) & 0x3;
> > +}
> > +
> > +int gpio_request(unsigned gpio, const char *label)
> > +{
> > +       return 0;
> > +}
> > +
> > +int gpio_free(unsigned gpio)
> > +{
> > +       return 0;
> > +}
> > +
> > +int gpio_direction_input(unsigned gpio)
> > +{
> > +       return writel(GPIO_FULLPORT(gpio), GPIO_INPUT << GPIO_BIT(gpio));
> > +}
> > +
> > +int gpio_direction_output(unsigned gpio, int value)
> > +{
> > +       writel(GPIO_FULLPORT(gpio), GPIO_OUTPUT << GPIO_BIT(gpio));
> > +       return gpio_set_value(gpio, value);
> > +}
> > --
> > 1.7.9.5
> > 
> > _______________________________________________
> > U-Boot mailing list
> > U-Boot at lists.denx.de
> > http://lists.denx.de/mailman/listinfo/u-boot
> 
> Thanks.
> Minkyu Kang.


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