arch/arm/mach-gemini/gpio.c

   1 /*
   2  * Gemini gpiochip and interrupt routines
   3  *
   4  * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
   5  *
   6  * Based on plat-mxc/gpio.c:
   7  *  MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
   8  *  Copyright 2008 Juergen Beisert, kernel@pengutronix.de
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/init.h>
  18 #include <linux/io.h>
  19 #include <linux/irq.h>
  20 #include <linux/gpio.h>
  21
  22 #include <mach/hardware.h>
  23 #include <mach/irqs.h>
  24
  25 #define GPIO_BASE(x)            IO_ADDRESS(GEMINI_GPIO_BASE(x))
  26 #define irq_to_gpio(x)          ((x) - GPIO_IRQ_BASE)
  27
  28 /* GPIO registers definition */
  29 #define GPIO_DATA_OUT           0x0
  30 #define GPIO_DATA_IN            0x4
  31 #define GPIO_DIR                0x8
  32 #define GPIO_DATA_SET           0x10
  33 #define GPIO_DATA_CLR           0x14
  34 #define GPIO_PULL_EN            0x18
  35 #define GPIO_PULL_TYPE          0x1C
  36 #define GPIO_INT_EN             0x20
  37 #define GPIO_INT_STAT           0x24
  38 #define GPIO_INT_MASK           0x2C
  39 #define GPIO_INT_CLR            0x30
  40 #define GPIO_INT_TYPE           0x34
  41 #define GPIO_INT_BOTH_EDGE      0x38
  42 #define GPIO_INT_LEVEL          0x3C
  43 #define GPIO_DEBOUNCE_EN        0x40
  44 #define GPIO_DEBOUNCE_PRESCALE  0x44
  45
  46 #define GPIO_PORT_NUM           3
  47
  48 static void _set_gpio_irqenable(void __iomem *base, unsigned int index,
  49                                 int enable)
  50 {
  51         unsigned int reg;
  52
  53         reg = __raw_readl(base + GPIO_INT_EN);
  54         reg = (reg & (~(1 << index))) | (!!enable << index);
  55         __raw_writel(reg, base + GPIO_INT_EN);
  56 }
  57
  58 static void gpio_ack_irq(struct irq_data *d)
  59 {
  60         unsigned int gpio = irq_to_gpio(d->irq);
  61         void __iomem *base = GPIO_BASE(gpio / 32);
  62
  63         __raw_writel(1 << (gpio % 32), base + GPIO_INT_CLR);
  64 }
  65
  66 static void gpio_mask_irq(struct irq_data *d)
  67 {
  68         unsigned int gpio = irq_to_gpio(d->irq);
  69         void __iomem *base = GPIO_BASE(gpio / 32);
  70
  71         _set_gpio_irqenable(base, gpio % 32, 0);
  72 }
  73
  74 static void gpio_unmask_irq(struct irq_data *d)
  75 {
  76         unsigned int gpio = irq_to_gpio(d->irq);
  77         void __iomem *base = GPIO_BASE(gpio / 32);
  78
  79         _set_gpio_irqenable(base, gpio % 32, 1);
  80 }
  81
  82 static int gpio_set_irq_type(struct irq_data *d, unsigned int type)
  83 {
  84         unsigned int gpio = irq_to_gpio(d->irq);
  85         unsigned int gpio_mask = 1 << (gpio % 32);
  86         void __iomem *base = GPIO_BASE(gpio / 32);
  87         unsigned int reg_both, reg_level, reg_type;
  88
  89         reg_type = __raw_readl(base + GPIO_INT_TYPE);
  90         reg_level = __raw_readl(base + GPIO_INT_LEVEL);
  91         reg_both = __raw_readl(base + GPIO_INT_BOTH_EDGE);
  92
  93         switch (type) {
  94         case IRQ_TYPE_EDGE_BOTH:
  95                 reg_type &= ~gpio_mask;
  96                 reg_both |= gpio_mask;
  97                 break;
  98         case IRQ_TYPE_EDGE_RISING:
  99                 reg_type &= ~gpio_mask;
 100                 reg_both &= ~gpio_mask;
 101                 reg_level &= ~gpio_mask;
 102                 break;
 103         case IRQ_TYPE_EDGE_FALLING:
 104                 reg_type &= ~gpio_mask;
 105                 reg_both &= ~gpio_mask;
 106                 reg_level |= gpio_mask;
 107                 break;
 108         case IRQ_TYPE_LEVEL_HIGH:
 109                 reg_type |= gpio_mask;
 110                 reg_level &= ~gpio_mask;
 111                 break;
 112         case IRQ_TYPE_LEVEL_LOW:
 113                 reg_type |= gpio_mask;
 114                 reg_level |= gpio_mask;
 115                 break;
 116         default:
 117                 return -EINVAL;
 118         }
 119
 120         __raw_writel(reg_type, base + GPIO_INT_TYPE);
 121         __raw_writel(reg_level, base + GPIO_INT_LEVEL);
 122         __raw_writel(reg_both, base + GPIO_INT_BOTH_EDGE);
 123
 124         gpio_ack_irq(d);
 125
 126         return 0;
 127 }
 128
 129 static void gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
 130 {
 131         unsigned int port = (unsigned int)irq_desc_get_handler_data(desc);
 132         unsigned int gpio_irq_no, irq_stat;
 133
 134         irq_stat = __raw_readl(GPIO_BASE(port) + GPIO_INT_STAT);
 135
 136         gpio_irq_no = GPIO_IRQ_BASE + port * 32;
 137         for (; irq_stat != 0; irq_stat >>= 1, gpio_irq_no++) {
 138
 139                 if ((irq_stat & 1) == 0)
 140                         continue;
 141
 142                 generic_handle_irq(gpio_irq_no);
 143         }
 144 }
 145
 146 static struct irq_chip gpio_irq_chip = {
 147         .name = "GPIO",
 148         .irq_ack = gpio_ack_irq,
 149         .irq_mask = gpio_mask_irq,
 150         .irq_unmask = gpio_unmask_irq,
 151         .irq_set_type = gpio_set_irq_type,
 152 };
 153
 154 static void _set_gpio_direction(struct gpio_chip *chip, unsigned offset,
 155                                 int dir)
 156 {
 157         void __iomem *base = GPIO_BASE(offset / 32);
 158         unsigned int reg;
 159
 160         reg = __raw_readl(base + GPIO_DIR);
 161         if (dir)
 162                 reg |= 1 << (offset % 32);
 163         else
 164                 reg &= ~(1 << (offset % 32));
 165         __raw_writel(reg, base + GPIO_DIR);
 166 }
 167
 168 static void gemini_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 169 {
 170         void __iomem *base = GPIO_BASE(offset / 32);
 171
 172         if (value)
 173                 __raw_writel(1 << (offset % 32), base + GPIO_DATA_SET);
 174         else
 175                 __raw_writel(1 << (offset % 32), base + GPIO_DATA_CLR);
 176 }
 177
 178 static int gemini_gpio_get(struct gpio_chip *chip, unsigned offset)
 179 {
 180         void __iomem *base = GPIO_BASE(offset / 32);
 181
 182         return (__raw_readl(base + GPIO_DATA_IN) >> (offset % 32)) & 1;
 183 }
 184
 185 static int gemini_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 186 {
 187         _set_gpio_direction(chip, offset, 0);
 188         return 0;
 189 }
 190
 191 static int gemini_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
 192                                         int value)
 193 {
 194         _set_gpio_direction(chip, offset, 1);
 195         gemini_gpio_set(chip, offset, value);
 196         return 0;
 197 }
 198
 199 static struct gpio_chip gemini_gpio_chip = {
 200         .label                  = "Gemini",
 201         .direction_input        = gemini_gpio_direction_input,
 202         .get                    = gemini_gpio_get,
 203         .direction_output       = gemini_gpio_direction_output,
 204         .set                    = gemini_gpio_set,
 205         .base                   = 0,
 206         .ngpio                  = GPIO_PORT_NUM * 32,
 207 };
 208
 209 void __init gemini_gpio_init(void)
 210 {
 211         int i, j;
 212
 213         for (i = 0; i < GPIO_PORT_NUM; i++) {
 214                 /* disable, unmask and clear all interrupts */
 215                 __raw_writel(0x0, GPIO_BASE(i) + GPIO_INT_EN);
 216                 __raw_writel(0x0, GPIO_BASE(i) + GPIO_INT_MASK);
 217                 __raw_writel(~0x0, GPIO_BASE(i) + GPIO_INT_CLR);
 218
 219                 for (j = GPIO_IRQ_BASE + i * 32;
 220                      j < GPIO_IRQ_BASE + (i + 1) * 32; j++) {
 221                         irq_set_chip_and_handler(j, &gpio_irq_chip,
 222                                                  handle_edge_irq);
 223                         set_irq_flags(j, IRQF_VALID);
 224                 }
 225
 226                 irq_set_chained_handler(IRQ_GPIO(i), gpio_irq_handler);
 227                 irq_set_handler_data(IRQ_GPIO(i), (void *)i);
 228         }
 229
 230         BUG_ON(gpiochip_add(&gemini_gpio_chip));
 231 }