arch/sh/boards/mach-sdk7786/gpio.c

   1 /*
   2  * SDK7786 FPGA USRGPIR Support.
   3  *
   4  * Copyright (C) 2010  Paul Mundt
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10 #include <linux/init.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/gpio.h>
  13 #include <linux/irq.h>
  14 #include <linux/kernel.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/io.h>
  17 #include <mach/fpga.h>
  18
  19 #define NR_FPGA_GPIOS   8
  20
  21 static const char *usrgpir_gpio_names[NR_FPGA_GPIOS] = {
  22         "in0", "in1", "in2", "in3", "in4", "in5", "in6", "in7",
  23 };
  24
  25 static int usrgpir_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
  26 {
  27         /* always in */
  28         return 0;
  29 }
  30
  31 static int usrgpir_gpio_get(struct gpio_chip *chip, unsigned gpio)
  32 {
  33         return !!(fpga_read_reg(USRGPIR) & (1 << gpio));
  34 }
  35
  36 static struct gpio_chip usrgpir_gpio_chip = {
  37         .label                  = "sdk7786-fpga",
  38         .names                  = usrgpir_gpio_names,
  39         .direction_input        = usrgpir_gpio_direction_input,
  40         .get                    = usrgpir_gpio_get,
  41         .base                   = -1, /* don't care */
  42         .ngpio                  = NR_FPGA_GPIOS,
  43 };
  44
  45 static int __init usrgpir_gpio_setup(void)
  46 {
  47         return gpiochip_add(&usrgpir_gpio_chip);
  48 }
  49 device_initcall(usrgpir_gpio_setup);