release/src-rt-6.x/linux/linux-2.6/arch/arm/mach-imx/irq.c

   1 /*
   2  *  linux/arch/arm/mach-imx/irq.c
   3  *
   4  *  Copyright (C) 1999 ARM Limited
   5  *  Copyright (C) 2002 Shane Nay (shane@minirl.com)
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (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, MA  02111-1307  USA
  20  *
  21  *  03/03/2004   Sascha Hauer <sascha@saschahauer.de>
  22  *               Copied from the motorola bsp package and added gpio demux
  23  *               interrupt handler
  24  */
  25
  26 #include <linux/init.h>
  27 #include <linux/list.h>
  28 #include <linux/timer.h>
  29
  30 #include <asm/hardware.h>
  31 #include <asm/irq.h>
  32 #include <asm/io.h>
  33
  34 #include <asm/mach/irq.h>
  35
  36 /*
  37  *
  38  * We simply use the ENABLE DISABLE registers inside of the IMX
  39  * to turn on/off specific interrupts.  FIXME- We should
  40  * also add support for the accelerated interrupt controller
  41  * by putting offets to irq jump code in the appropriate
  42  * places.
  43  *
  44  */
  45
  46 #define INTENNUM_OFF              0x8
  47 #define INTDISNUM_OFF             0xC
  48
  49 #define VA_AITC_BASE              IO_ADDRESS(IMX_AITC_BASE)
  50 #define IMX_AITC_INTDISNUM       (VA_AITC_BASE + INTDISNUM_OFF)
  51 #define IMX_AITC_INTENNUM        (VA_AITC_BASE + INTENNUM_OFF)
  52
  53 #if 0
  54 #define DEBUG_IRQ(fmt...)       printk(fmt)
  55 #else
  56 #define DEBUG_IRQ(fmt...)       do { } while (0)
  57 #endif
  58
  59 static void
  60 imx_mask_irq(unsigned int irq)
  61 {
  62         __raw_writel(irq, IMX_AITC_INTDISNUM);
  63 }
  64
  65 static void
  66 imx_unmask_irq(unsigned int irq)
  67 {
  68         __raw_writel(irq, IMX_AITC_INTENNUM);
  69 }
  70
  71 static int
  72 imx_gpio_irq_type(unsigned int _irq, unsigned int type)
  73 {
  74         unsigned int irq_type = 0, irq, reg, bit;
  75
  76         irq = _irq - IRQ_GPIOA(0);
  77         reg = irq >> 5;
  78         bit = 1 << (irq % 32);
  79
  80         if (type == IRQT_PROBE) {
  81                 /* Don't mess with enabled GPIOs using preconfigured edges or
  82                    GPIOs set to alternate function during probe */
  83                 /* TODO: support probe */
  84 //              if ((GPIO_IRQ_rising_edge[idx] | GPIO_IRQ_falling_edge[idx]) &
  85 //                  GPIO_bit(gpio))
  86 //                      return 0;
  87 //              if (GAFR(gpio) & (0x3 << (((gpio) & 0xf)*2)))
  88 //                      return 0;
  89 //              type = __IRQT_RISEDGE | __IRQT_FALEDGE;
  90         }
  91
  92         GIUS(reg) |= bit;
  93         DDIR(reg) &= ~(bit);
  94
  95         DEBUG_IRQ("setting type of irq %d to ", _irq);
  96
  97         if (type & __IRQT_RISEDGE) {
  98                 DEBUG_IRQ("rising edges\n");
  99                 irq_type = 0x0;
 100         }
 101         if (type & __IRQT_FALEDGE) {
 102                 DEBUG_IRQ("falling edges\n");
 103                 irq_type = 0x1;
 104         }
 105         if (type & __IRQT_LOWLVL) {
 106                 DEBUG_IRQ("low level\n");
 107                 irq_type = 0x3;
 108         }
 109         if (type & __IRQT_HIGHLVL) {
 110                 DEBUG_IRQ("high level\n");
 111                 irq_type = 0x2;
 112         }
 113
 114         if (irq % 32 < 16) {
 115                 ICR1(reg) = (ICR1(reg) & ~(0x3 << ((irq % 16) * 2))) |
 116                     (irq_type << ((irq % 16) * 2));
 117         } else {
 118                 ICR2(reg) = (ICR2(reg) & ~(0x3 << ((irq % 16) * 2))) |
 119                     (irq_type << ((irq % 16) * 2));
 120         }
 121
 122         return 0;
 123
 124 }
 125
 126 static void
 127 imx_gpio_ack_irq(unsigned int irq)
 128 {
 129         DEBUG_IRQ("%s: irq %d\n", __FUNCTION__, irq);
 130         ISR(IRQ_TO_REG(irq)) = 1 << ((irq - IRQ_GPIOA(0)) % 32);
 131 }
 132
 133 static void
 134 imx_gpio_mask_irq(unsigned int irq)
 135 {
 136         DEBUG_IRQ("%s: irq %d\n", __FUNCTION__, irq);
 137         IMR(IRQ_TO_REG(irq)) &= ~( 1 << ((irq - IRQ_GPIOA(0)) % 32));
 138 }
 139
 140 static void
 141 imx_gpio_unmask_irq(unsigned int irq)
 142 {
 143         DEBUG_IRQ("%s: irq %d\n", __FUNCTION__, irq);
 144         IMR(IRQ_TO_REG(irq)) |= 1 << ((irq - IRQ_GPIOA(0)) % 32);
 145 }
 146
 147 static void
 148 imx_gpio_handler(unsigned int mask, unsigned int irq,
 149                  struct irq_desc *desc)
 150 {
 151         desc = irq_desc + irq;
 152         while (mask) {
 153                 if (mask & 1) {
 154                         DEBUG_IRQ("handling irq %d\n", irq);
 155                         desc_handle_irq(irq, desc);
 156                 }
 157                 irq++;
 158                 desc++;
 159                 mask >>= 1;
 160         }
 161 }
 162
 163 static void
 164 imx_gpioa_demux_handler(unsigned int irq_unused, struct irq_desc *desc)
 165 {
 166         unsigned int mask, irq;
 167
 168         mask = ISR(0);
 169         irq = IRQ_GPIOA(0);
 170         imx_gpio_handler(mask, irq, desc);
 171 }
 172
 173 static void
 174 imx_gpiob_demux_handler(unsigned int irq_unused, struct irq_desc *desc)
 175 {
 176         unsigned int mask, irq;
 177
 178         mask = ISR(1);
 179         irq = IRQ_GPIOB(0);
 180         imx_gpio_handler(mask, irq, desc);
 181 }
 182
 183 static void
 184 imx_gpioc_demux_handler(unsigned int irq_unused, struct irq_desc *desc)
 185 {
 186         unsigned int mask, irq;
 187
 188         mask = ISR(2);
 189         irq = IRQ_GPIOC(0);
 190         imx_gpio_handler(mask, irq, desc);
 191 }
 192
 193 static void
 194 imx_gpiod_demux_handler(unsigned int irq_unused, struct irq_desc *desc)
 195 {
 196         unsigned int mask, irq;
 197
 198         mask = ISR(3);
 199         irq = IRQ_GPIOD(0);
 200         imx_gpio_handler(mask, irq, desc);
 201 }
 202
 203 static struct irq_chip imx_internal_chip = {
 204         .name = "MPU",
 205         .ack = imx_mask_irq,
 206         .mask = imx_mask_irq,
 207         .unmask = imx_unmask_irq,
 208 };
 209
 210 static struct irq_chip imx_gpio_chip = {
 211         .name = "GPIO",
 212         .ack = imx_gpio_ack_irq,
 213         .mask = imx_gpio_mask_irq,
 214         .unmask = imx_gpio_unmask_irq,
 215         .set_type = imx_gpio_irq_type,
 216 };
 217
 218 void __init
 219 imx_init_irq(void)
 220 {
 221         unsigned int irq;
 222
 223         DEBUG_IRQ("Initializing imx interrupts\n");
 224
 225         /* Mask all interrupts initially */
 226         IMR(0) = 0;
 227         IMR(1) = 0;
 228         IMR(2) = 0;
 229         IMR(3) = 0;
 230
 231         for (irq = 0; irq < IMX_IRQS; irq++) {
 232                 set_irq_chip(irq, &imx_internal_chip);
 233                 set_irq_handler(irq, handle_level_irq);
 234                 set_irq_flags(irq, IRQF_VALID);
 235         }
 236
 237         for (irq = IRQ_GPIOA(0); irq < IRQ_GPIOD(32); irq++) {
 238                 set_irq_chip(irq, &imx_gpio_chip);
 239                 set_irq_handler(irq, handle_edge_irq);
 240                 set_irq_flags(irq, IRQF_VALID);
 241         }
 242
 243         set_irq_chained_handler(GPIO_INT_PORTA, imx_gpioa_demux_handler);
 244         set_irq_chained_handler(GPIO_INT_PORTB, imx_gpiob_demux_handler);
 245         set_irq_chained_handler(GPIO_INT_PORTC, imx_gpioc_demux_handler);
 246         set_irq_chained_handler(GPIO_INT_PORTD, imx_gpiod_demux_handler);
 247
 248         /* Disable all interrupts initially. */
 249         /* In IMX this is done in the bootloader. */
 250 }