target/linux/s3c24xx/files-2.6.30/arch/arm/mach-s3c2442/gta02-shadow.c

   1 /*
   2  * Common utility code for GTA02
   3  *
   4  * Copyright (C) 2008 by Openmoko, Inc.
   5  * Author: Holger Hans Peter Freyther <freyther@openmoko.org>
   6  * All rights reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  *
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/io.h>
  27 #include <linux/irq.h>
  28
  29 #include <asm/gpio.h>
  30 #include <mach/regs-gpio.h>
  31 #include <linux/gta02-shadow.h>
  32
  33 /**
  34  * Shadow GPIO bank B handling. For the LEDs we need to keep track of the state
  35  * in software. The s3c2410_gpio_setpin must not be used for GPIOs on bank B
  36  */
  37 static unsigned long gpb_mask;
  38 static unsigned long gpb_state;
  39
  40 void gta02_gpb_add_shadow_gpio(unsigned int gpio)
  41 {
  42         unsigned long offset = S3C2410_GPIO_OFFSET(gpio);
  43         unsigned long flags;
  44
  45         local_irq_save(flags);
  46         gpb_mask |= 1L << offset;
  47         local_irq_restore(flags);
  48 }
  49 EXPORT_SYMBOL(gta02_gpb_add_shadow_gpio);
  50
  51 static void set_shadow_gpio(unsigned long offset, unsigned int value)
  52 {
  53         unsigned long state = value != 0;
  54
  55         gpb_state &= ~(1L << offset);
  56         gpb_state |= state << offset;
  57 }
  58
  59 void gta02_gpb_setpin(unsigned int pin, unsigned to)
  60 {
  61         void __iomem *base = S3C24XX_GPIO_BASE(S3C2410_GPB0);
  62         unsigned long offset = S3C2410_GPIO_OFFSET(pin);
  63         unsigned long flags;
  64         unsigned long dat;
  65
  66         BUG_ON(base != S3C24XX_GPIO_BASE(pin));
  67
  68         local_irq_save(flags);
  69         dat = __raw_readl(base + 0x04);
  70
  71         /* Add the shadow values */
  72         dat &= ~gpb_mask;
  73         dat |= gpb_state;
  74
  75         /* Do the operation like s3c2410_gpio_setpin */
  76         dat &= ~(1L << offset);
  77         dat |= to << offset;
  78
  79         /* Update the shadow state */
  80         if ((1L << offset) & gpb_mask)
  81                 set_shadow_gpio(offset, to);
  82
  83         __raw_writel(dat, base + 0x04);
  84         local_irq_restore(flags);
  85 }
  86 EXPORT_SYMBOL(gta02_gpb_setpin);