arch/arm/mach-ep93xx/gpio.c

   1 /*
   2  * linux/arch/arm/mach-ep93xx/gpio.c
   3  *
   4  * Generic EP93xx GPIO handling
   5  *
   6  * Copyright (c) 2008 Ryan Mallon <ryan@bluewatersys.com>
   7  *
   8  * Based on code originally from:
   9  *  linux/arch/arm/mach-ep93xx/core.c
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License version 2 as
  13  *  published by the Free Software Foundation.
  14  */
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/seq_file.h>
  19 #include <linux/io.h>
  20 #include <linux/gpio.h>
  21 #include <linux/irq.h>
  22
  23 #include <mach/hardware.h>
  24
  25 struct ep93xx_gpio_chip {
  26         struct gpio_chip        chip;
  27
  28         void __iomem            *data_reg;
  29         void __iomem            *data_dir_reg;
  30 };
  31
  32 #define to_ep93xx_gpio_chip(c) container_of(c, struct ep93xx_gpio_chip, chip)
  33
  34 /* From core.c */
  35 extern void ep93xx_gpio_int_mask(unsigned line);
  36 extern void ep93xx_gpio_update_int_params(unsigned port);
  37
  38 static int ep93xx_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
  39 {
  40         struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
  41         unsigned long flags;
  42         u8 v;
  43
  44         local_irq_save(flags);
  45         v = __raw_readb(ep93xx_chip->data_dir_reg);
  46         v &= ~(1 << offset);
  47         __raw_writeb(v, ep93xx_chip->data_dir_reg);
  48         local_irq_restore(flags);
  49
  50         return 0;
  51 }
  52
  53 static int ep93xx_gpio_direction_output(struct gpio_chip *chip,
  54                                         unsigned offset, int val)
  55 {
  56         struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
  57         unsigned long flags;
  58         int line;
  59         u8 v;
  60
  61         local_irq_save(flags);
  62
  63         /* Set the value */
  64         v = __raw_readb(ep93xx_chip->data_reg);
  65         if (val)
  66                 v |= (1 << offset);
  67         else
  68                 v &= ~(1 << offset);
  69         __raw_writeb(v, ep93xx_chip->data_reg);
  70
  71         /* Drive as an output */
  72         line = chip->base + offset;
  73         if (line <= EP93XX_GPIO_LINE_MAX_IRQ) {
  74                 /* Ports A/B/F */
  75                 ep93xx_gpio_int_mask(line);
  76                 ep93xx_gpio_update_int_params(line >> 3);
  77         }
  78
  79         v = __raw_readb(ep93xx_chip->data_dir_reg);
  80         v |= (1 << offset);
  81         __raw_writeb(v, ep93xx_chip->data_dir_reg);
  82
  83         local_irq_restore(flags);
  84
  85         return 0;
  86 }
  87
  88 static int ep93xx_gpio_get(struct gpio_chip *chip, unsigned offset)
  89 {
  90         struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
  91
  92         return !!(__raw_readb(ep93xx_chip->data_reg) & (1 << offset));
  93 }
  94
  95 static void ep93xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
  96 {
  97         struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
  98         unsigned long flags;
  99         u8 v;
 100
 101         local_irq_save(flags);
 102         v = __raw_readb(ep93xx_chip->data_reg);
 103         if (val)
 104                 v |= (1 << offset);
 105         else
 106                 v &= ~(1 << offset);
 107         __raw_writeb(v, ep93xx_chip->data_reg);
 108         local_irq_restore(flags);
 109 }
 110
 111 static void ep93xx_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 112 {
 113         struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
 114         u8 data_reg, data_dir_reg;
 115         int gpio, i;
 116
 117         data_reg = __raw_readb(ep93xx_chip->data_reg);
 118         data_dir_reg = __raw_readb(ep93xx_chip->data_dir_reg);
 119
 120         gpio = ep93xx_chip->chip.base;
 121         for (i = 0; i < chip->ngpio; i++, gpio++) {
 122                 int is_out = data_dir_reg & (1 << i);
 123
 124                 seq_printf(s, " %s%d gpio-%-3d (%-12s) %s %s",
 125                                 chip->label, i, gpio,
 126                                 gpiochip_is_requested(chip, i) ? : "",
 127                                 is_out ? "out" : "in ",
 128                                 (data_reg & (1 << i)) ? "hi" : "lo");
 129
 130                 if (!is_out) {
 131                         int irq = gpio_to_irq(gpio);
 132                         struct irq_desc *desc = irq_desc + irq;
 133
 134                         if (irq >= 0 && desc->action) {
 135                                 char *trigger;
 136
 137                                 switch (desc->status & IRQ_TYPE_SENSE_MASK) {
 138                                 case IRQ_TYPE_NONE:
 139                                         trigger = "(default)";
 140                                         break;
 141                                 case IRQ_TYPE_EDGE_FALLING:
 142                                         trigger = "edge-falling";
 143                                         break;
 144                                 case IRQ_TYPE_EDGE_RISING:
 145                                         trigger = "edge-rising";
 146                                         break;
 147                                 case IRQ_TYPE_EDGE_BOTH:
 148                                         trigger = "edge-both";
 149                                         break;
 150                                 case IRQ_TYPE_LEVEL_HIGH:
 151                                         trigger = "level-high";
 152                                         break;
 153                                 case IRQ_TYPE_LEVEL_LOW:
 154                                         trigger = "level-low";
 155                                         break;
 156                                 default:
 157                                         trigger = "?trigger?";
 158                                         break;
 159                                 }
 160
 161                                 seq_printf(s, " irq-%d %s%s",
 162                                                 irq, trigger,
 163                                                 (desc->status & IRQ_WAKEUP)
 164                                                         ? " wakeup" : "");
 165                         }
 166                 }
 167
 168                 seq_printf(s, "\n");
 169         }
 170 }
 171
 172 #define EP93XX_GPIO_BANK(name, dr, ddr, base_gpio)                      \
 173         {                                                               \
 174                 .chip = {                                               \
 175                         .label            = name,                       \
 176                         .direction_input  = ep93xx_gpio_direction_input, \
 177                         .direction_output = ep93xx_gpio_direction_output, \
 178                         .get              = ep93xx_gpio_get,            \
 179                         .set              = ep93xx_gpio_set,            \
 180                         .dbg_show         = ep93xx_gpio_dbg_show,       \
 181                         .base             = base_gpio,                  \
 182                         .ngpio            = 8,                          \
 183                 },                                                      \
 184                 .data_reg       = EP93XX_GPIO_REG(dr),                  \
 185                 .data_dir_reg   = EP93XX_GPIO_REG(ddr),                 \
 186         }
 187
 188 static struct ep93xx_gpio_chip ep93xx_gpio_banks[] = {
 189         EP93XX_GPIO_BANK("A", 0x00, 0x10, 0),
 190         EP93XX_GPIO_BANK("B", 0x04, 0x14, 8),
 191         EP93XX_GPIO_BANK("C", 0x08, 0x18, 40),
 192         EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24),
 193         EP93XX_GPIO_BANK("E", 0x20, 0x24, 32),
 194         EP93XX_GPIO_BANK("F", 0x30, 0x34, 16),
 195         EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48),
 196         EP93XX_GPIO_BANK("H", 0x40, 0x44, 56),
 197 };
 198
 199 void __init ep93xx_gpio_init(void)
 200 {
 201         int i;
 202
 203         for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++)
 204                 gpiochip_add(&ep93xx_gpio_banks[i].chip);
 205 }