arch/arm/plat-mxc/gpio.c

   1 /*
   2  * MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
   3  * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
   4  *
   5  * Based on code from Freescale,
   6  * Copyright 2004-2006 Freescale Semiconductor, Inc. All Rights Reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version 2
  11  * of the License, or (at your option) any later version.
  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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/io.h>
  24 #include <linux/irq.h>
  25 #include <linux/gpio.h>
  26 #include <asm/hardware.h>
  27 #include <asm-generic/bug.h>
  28
  29 static struct mxc_gpio_port *mxc_gpio_ports;
  30 static int gpio_table_size;
  31
  32 /* Note: This driver assumes 32 GPIOs are handled in one register */
  33
  34 static void _clear_gpio_irqstatus(struct mxc_gpio_port *port, u32 index)
  35 {
  36         __raw_writel(1 << index, port->base + GPIO_ISR);
  37 }
  38
  39 static void _set_gpio_irqenable(struct mxc_gpio_port *port, u32 index,
  40                                 int enable)
  41 {
  42         u32 l;
  43
  44         l = __raw_readl(port->base + GPIO_IMR);
  45         l = (l & (~(1 << index))) | (!!enable << index);
  46         __raw_writel(l, port->base + GPIO_IMR);
  47 }
  48
  49 static void gpio_ack_irq(u32 irq)
  50 {
  51         u32 gpio = irq_to_gpio(irq);
  52         _clear_gpio_irqstatus(&mxc_gpio_ports[gpio / 32], gpio & 0x1f);
  53 }
  54
  55 static void gpio_mask_irq(u32 irq)
  56 {
  57         u32 gpio = irq_to_gpio(irq);
  58         _set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 0);
  59 }
  60
  61 static void gpio_unmask_irq(u32 irq)
  62 {
  63         u32 gpio = irq_to_gpio(irq);
  64         _set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 1);
  65 }
  66
  67 static int gpio_set_irq_type(u32 irq, u32 type)
  68 {
  69         u32 gpio = irq_to_gpio(irq);
  70         struct mxc_gpio_port *port = &mxc_gpio_ports[gpio / 32];
  71         u32 bit, val;
  72         int edge;
  73         void __iomem *reg = port->base;
  74
  75         switch (type) {
  76         case IRQT_RISING:
  77                 edge = GPIO_INT_RISE_EDGE;
  78                 break;
  79         case IRQT_FALLING:
  80                 edge = GPIO_INT_FALL_EDGE;
  81                 break;
  82         case IRQT_LOW:
  83                 edge = GPIO_INT_LOW_LEV;
  84                 break;
  85         case IRQT_HIGH:
  86                 edge = GPIO_INT_HIGH_LEV;
  87                 break;
  88         default:        /* this includes IRQT_BOTHEDGE */
  89                 return -EINVAL;
  90         }
  91
  92         reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */
  93         bit = gpio & 0xf;
  94         val = __raw_readl(reg) & ~(0x3 << (bit << 1));
  95         __raw_writel(val | (edge << (bit << 1)), reg);
  96         _clear_gpio_irqstatus(port, gpio & 0x1f);
  97
  98         return 0;
  99 }
 100
 101 /* handle n interrupts in one status register */
 102 static void mxc_gpio_irq_handler(struct mxc_gpio_port *port, u32 irq_stat)
 103 {
 104         u32 gpio_irq_no;
 105
 106         gpio_irq_no = port->virtual_irq_start;
 107         for (; irq_stat != 0; irq_stat >>= 1, gpio_irq_no++) {
 108
 109                 if ((irq_stat & 1) == 0)
 110                         continue;
 111
 112                 BUG_ON(!(irq_desc[gpio_irq_no].handle_irq));
 113                 irq_desc[gpio_irq_no].handle_irq(gpio_irq_no,
 114                                 &irq_desc[gpio_irq_no]);
 115         }
 116 }
 117
 118 #ifdef CONFIG_ARCH_MX3
 119 /* MX3 has one interrupt *per* gpio port */
 120 static void mx3_gpio_irq_handler(u32 irq, struct irq_desc *desc)
 121 {
 122         u32 irq_stat;
 123         struct mxc_gpio_port *port = (struct mxc_gpio_port *)get_irq_data(irq);
 124
 125         irq_stat = __raw_readl(port->base + GPIO_ISR) &
 126                         __raw_readl(port->base + GPIO_IMR);
 127         BUG_ON(!irq_stat);
 128         mxc_gpio_irq_handler(port, irq_stat);
 129 }
 130 #endif
 131
 132 #ifdef CONFIG_ARCH_MX2
 133 /* MX2 has one interrupt *for all* gpio ports */
 134 static void mx2_gpio_irq_handler(u32 irq, struct irq_desc *desc)
 135 {
 136         int i;
 137         u32 irq_msk, irq_stat;
 138         struct mxc_gpio_port *port = (struct mxc_gpio_port *)get_irq_data(irq);
 139
 140         /* walk through all interrupt status registers */
 141         for (i = 0; i < gpio_table_size; i++) {
 142                 irq_msk = __raw_readl(port[i].base + GPIO_IMR);
 143                 if (!irq_msk)
 144                         continue;
 145
 146                 irq_stat = __raw_readl(port[i].base + GPIO_ISR) & irq_msk;
 147                 if (irq_stat)
 148                         mxc_gpio_irq_handler(&port[i], irq_stat);
 149         }
 150 }
 151 #endif
 152
 153 static struct irq_chip gpio_irq_chip = {
 154         .ack = gpio_ack_irq,
 155         .mask = gpio_mask_irq,
 156         .unmask = gpio_unmask_irq,
 157         .set_type = gpio_set_irq_type,
 158 };
 159
 160 static void _set_gpio_direction(struct gpio_chip *chip, unsigned offset,
 161                                 int dir)
 162 {
 163         struct mxc_gpio_port *port =
 164                 container_of(chip, struct mxc_gpio_port, chip);
 165         u32 l;
 166
 167         l = __raw_readl(port->base + GPIO_GDIR);
 168         if (dir)
 169                 l |= 1 << offset;
 170         else
 171                 l &= ~(1 << offset);
 172         __raw_writel(l, port->base + GPIO_GDIR);
 173 }
 174
 175 static void mxc_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 176 {
 177         struct mxc_gpio_port *port =
 178                 container_of(chip, struct mxc_gpio_port, chip);
 179         void __iomem *reg = port->base + GPIO_DR;
 180         u32 l;
 181
 182         l = (__raw_readl(reg) & (~(1 << offset))) | (value << offset);
 183         __raw_writel(l, reg);
 184 }
 185
 186 static int mxc_gpio_get(struct gpio_chip *chip, unsigned offset)
 187 {
 188         struct mxc_gpio_port *port =
 189                 container_of(chip, struct mxc_gpio_port, chip);
 190
 191         return (__raw_readl(port->base + GPIO_DR) >> offset) & 1;
 192 }
 193
 194 static int mxc_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 195 {
 196         _set_gpio_direction(chip, offset, 0);
 197         return 0;
 198 }
 199
 200 static int mxc_gpio_direction_output(struct gpio_chip *chip,
 201                                      unsigned offset, int value)
 202 {
 203         _set_gpio_direction(chip, offset, 1);
 204         mxc_gpio_set(chip, offset, value);
 205         return 0;
 206 }
 207
 208 int __init mxc_gpio_init(struct mxc_gpio_port *port, int cnt)
 209 {
 210         int i, j;
 211
 212         /* save for local usage */
 213         mxc_gpio_ports = port;
 214         gpio_table_size = cnt;
 215
 216         printk(KERN_INFO "MXC GPIO hardware\n");
 217
 218         for (i = 0; i < cnt; i++) {
 219                 /* disable the interrupt and clear the status */
 220                 __raw_writel(0, port[i].base + GPIO_IMR);
 221                 __raw_writel(~0, port[i].base + GPIO_ISR);
 222                 for (j = port[i].virtual_irq_start;
 223                         j < port[i].virtual_irq_start + 32; j++) {
 224                         set_irq_chip(j, &gpio_irq_chip);
 225                         set_irq_handler(j, handle_edge_irq);
 226                         set_irq_flags(j, IRQF_VALID);
 227                 }
 228
 229                 /* register gpio chip */
 230                 port[i].chip.direction_input = mxc_gpio_direction_input;
 231                 port[i].chip.direction_output = mxc_gpio_direction_output;
 232                 port[i].chip.get = mxc_gpio_get;
 233                 port[i].chip.set = mxc_gpio_set;
 234                 port[i].chip.base = i * 32;
 235                 port[i].chip.ngpio = 32;
 236
 237                 /* its a serious configuration bug when it fails */
 238                 BUG_ON( gpiochip_add(&port[i].chip) < 0 );
 239
 240 #ifdef CONFIG_ARCH_MX3
 241                 /* setup one handler for each entry */
 242                 set_irq_chained_handler(port[i].irq, mx3_gpio_irq_handler);
 243                 set_irq_data(port[i].irq, &port[i]);
 244 #endif
 245         }
 246
 247 #ifdef CONFIG_ARCH_MX2
 248         /* setup one handler for all GPIO interrupts */
 249         set_irq_chained_handler(port[0].irq, mx2_gpio_irq_handler);
 250         set_irq_data(port[0].irq, port);
 251 #endif
 252         return 0;
 253 }