cpu/arm926ejs/nomadik/gpio.c

   1 /*
   2  * (C) Copyright 2009 Alessandro Rubini
   3  *
   4  * See file CREDITS for list of people who contributed to this
   5  * project.
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 of
  10  * the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  20  * MA 02111-1307 USA
  21  */
  22
  23 #include <common.h>
  24 #include <asm/io.h>
  25 #include <asm/arch/gpio.h>
  26
  27 static unsigned long gpio_base[4] = {
  28         NOMADIK_GPIO0_BASE,
  29         NOMADIK_GPIO1_BASE,
  30         NOMADIK_GPIO2_BASE,
  31         NOMADIK_GPIO3_BASE
  32 };
  33
  34 enum gpio_registers {
  35         GPIO_DAT =      0x00,           /* data register */
  36         GPIO_DATS =     0x04,           /* data set */
  37         GPIO_DATC =     0x08,           /* data clear */
  38         GPIO_PDIS =     0x0c,           /* pull disable */
  39         GPIO_DIR =      0x10,           /* direction */
  40         GPIO_DIRS =     0x14,           /* direction set */
  41         GPIO_DIRC =     0x18,           /* direction clear */
  42         GPIO_AFSLA =    0x20,           /* alternate function select A */
  43         GPIO_AFSLB =    0x24,           /* alternate function select B */
  44 };
  45
  46 static inline unsigned long gpio_to_base(int gpio)
  47 {
  48         return gpio_base[gpio / 32];
  49 }
  50
  51 static inline u32 gpio_to_bit(int gpio)
  52 {
  53         return 1 << (gpio & 0x1f);
  54 }
  55
  56 void nmk_gpio_af(int gpio, int alternate_function)
  57 {
  58         unsigned long base = gpio_to_base(gpio);
  59         u32 bit = gpio_to_bit(gpio);
  60         u32 afunc, bfunc;
  61
  62         /* alternate function is 0..3, with one bit per register */
  63         afunc = readl(base + GPIO_AFSLA) & ~bit;
  64         bfunc = readl(base + GPIO_AFSLB) & ~bit;
  65         if (alternate_function & 1) afunc |= bit;
  66         if (alternate_function & 2) bfunc |= bit;
  67         writel(afunc, base + GPIO_AFSLA);
  68         writel(bfunc, base + GPIO_AFSLB);
  69 }
  70
  71 void nmk_gpio_dir(int gpio, int dir)
  72 {
  73         unsigned long base = gpio_to_base(gpio);
  74         u32 bit = gpio_to_bit(gpio);
  75
  76         if (dir)
  77                 writel(bit, base + GPIO_DIRS);
  78         else
  79                 writel(bit, base + GPIO_DIRC);
  80 }
  81
  82 void nmk_gpio_set(int gpio, int val)
  83 {
  84         unsigned long base = gpio_to_base(gpio);
  85         u32 bit = gpio_to_bit(gpio);
  86
  87         if (val)
  88                 writel(bit, base + GPIO_DATS);
  89         else
  90                 writel(bit, base + GPIO_DATC);
  91 }
  92
  93 int nmk_gpio_get(int gpio)
  94 {
  95         unsigned long base = gpio_to_base(gpio);
  96         u32 bit = gpio_to_bit(gpio);
  97
  98         return readl(base + GPIO_DAT) & bit;
  99 }