drivers/gpio/pl061.c

   1 /*
   2  *  linux/drivers/gpio/pl061.c
   3  *
   4  *  Copyright (C) 2008, 2009 Provigent Ltd.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * Driver for the ARM PrimeCell(tm) General Purpose Input/Output (PL061)
  11  *
  12  * Data sheet: ARM DDI 0190B, September 2000
  13  */
  14 #include <linux/spinlock.h>
  15 #include <linux/errno.h>
  16 #include <linux/module.h>
  17 #include <linux/list.h>
  18 #include <linux/io.h>
  19 #include <linux/ioport.h>
  20 #include <linux/irq.h>
  21 #include <linux/bitops.h>
  22 #include <linux/workqueue.h>
  23 #include <linux/gpio.h>
  24 #include <linux/device.h>
  25 #include <linux/amba/bus.h>
  26 #include <linux/amba/pl061.h>
  27 #include <linux/slab.h>
  28
  29 #define GPIODIR 0x400
  30 #define GPIOIS  0x404
  31 #define GPIOIBE 0x408
  32 #define GPIOIEV 0x40C
  33 #define GPIOIE  0x410
  34 #define GPIORIS 0x414
  35 #define GPIOMIS 0x418
  36 #define GPIOIC  0x41C
  37
  38 #define PL061_GPIO_NR   8
  39
  40 struct pl061_gpio {
  41         /* We use a list of pl061_gpio structs for each trigger IRQ in the main
  42          * interrupts controller of the system. We need this to support systems
  43          * in which more that one PL061s are connected to the same IRQ. The ISR
  44          * interates through this list to find the source of the interrupt.
  45          */
  46         struct list_head        list;
  47
  48         /* Each of the two spinlocks protects a different set of hardware
  49          * regiters and data structurs. This decouples the code of the IRQ from
  50          * the GPIO code. This also makes the case of a GPIO routine call from
  51          * the IRQ code simpler.
  52          */
  53         spinlock_t              lock;           /* GPIO registers */
  54         spinlock_t              irq_lock;       /* IRQ registers */
  55
  56         void __iomem            *base;
  57         unsigned                irq_base;
  58         struct gpio_chip        gc;
  59 };
  60
  61 static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
  62 {
  63         struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
  64         unsigned long flags;
  65         unsigned char gpiodir;
  66
  67         if (offset >= gc->ngpio)
  68                 return -EINVAL;
  69
  70         spin_lock_irqsave(&chip->lock, flags);
  71         gpiodir = readb(chip->base + GPIODIR);
  72         gpiodir &= ~(1 << offset);
  73         writeb(gpiodir, chip->base + GPIODIR);
  74         spin_unlock_irqrestore(&chip->lock, flags);
  75
  76         return 0;
  77 }
  78
  79 static int pl061_direction_output(struct gpio_chip *gc, unsigned offset,
  80                 int value)
  81 {
  82         struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
  83         unsigned long flags;
  84         unsigned char gpiodir;
  85
  86         if (offset >= gc->ngpio)
  87                 return -EINVAL;
  88
  89         spin_lock_irqsave(&chip->lock, flags);
  90         writeb(!!value << offset, chip->base + (1 << (offset + 2)));
  91         gpiodir = readb(chip->base + GPIODIR);
  92         gpiodir |= 1 << offset;
  93         writeb(gpiodir, chip->base + GPIODIR);
  94
  95         /*
  96          * gpio value is set again, because pl061 doesn't allow to set value of
  97          * a gpio pin before configuring it in OUT mode.
  98          */
  99         writeb(!!value << offset, chip->base + (1 << (offset + 2)));
 100         spin_unlock_irqrestore(&chip->lock, flags);
 101
 102         return 0;
 103 }
 104
 105 static int pl061_get_value(struct gpio_chip *gc, unsigned offset)
 106 {
 107         struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
 108
 109         return !!readb(chip->base + (1 << (offset + 2)));
 110 }
 111
 112 static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
 113 {
 114         struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
 115
 116         writeb(!!value << offset, chip->base + (1 << (offset + 2)));
 117 }
 118
 119 static int pl061_to_irq(struct gpio_chip *gc, unsigned offset)
 120 {
 121         struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
 122
 123         if (chip->irq_base == (unsigned) -1)
 124                 return -EINVAL;
 125
 126         return chip->irq_base + offset;
 127 }
 128
 129 /*
 130  * PL061 GPIO IRQ
 131  */
 132 static void pl061_irq_disable(unsigned irq)
 133 {
 134         struct pl061_gpio *chip = get_irq_chip_data(irq);
 135         int offset = irq - chip->irq_base;
 136         unsigned long flags;
 137         u8 gpioie;
 138
 139         spin_lock_irqsave(&chip->irq_lock, flags);
 140         gpioie = readb(chip->base + GPIOIE);
 141         gpioie &= ~(1 << offset);
 142         writeb(gpioie, chip->base + GPIOIE);
 143         spin_unlock_irqrestore(&chip->irq_lock, flags);
 144 }
 145
 146 static void pl061_irq_enable(unsigned irq)
 147 {
 148         struct pl061_gpio *chip = get_irq_chip_data(irq);
 149         int offset = irq - chip->irq_base;
 150         unsigned long flags;
 151         u8 gpioie;
 152
 153         spin_lock_irqsave(&chip->irq_lock, flags);
 154         gpioie = readb(chip->base + GPIOIE);
 155         gpioie |= 1 << offset;
 156         writeb(gpioie, chip->base + GPIOIE);
 157         spin_unlock_irqrestore(&chip->irq_lock, flags);
 158 }
 159
 160 static int pl061_irq_type(unsigned irq, unsigned trigger)
 161 {
 162         struct pl061_gpio *chip = get_irq_chip_data(irq);
 163         int offset = irq - chip->irq_base;
 164         unsigned long flags;
 165         u8 gpiois, gpioibe, gpioiev;
 166
 167         if (offset < 0 || offset >= PL061_GPIO_NR)
 168                 return -EINVAL;
 169
 170         spin_lock_irqsave(&chip->irq_lock, flags);
 171
 172         gpioiev = readb(chip->base + GPIOIEV);
 173
 174         gpiois = readb(chip->base + GPIOIS);
 175         if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
 176                 gpiois |= 1 << offset;
 177                 if (trigger & IRQ_TYPE_LEVEL_HIGH)
 178                         gpioiev |= 1 << offset;
 179                 else
 180                         gpioiev &= ~(1 << offset);
 181         } else
 182                 gpiois &= ~(1 << offset);
 183         writeb(gpiois, chip->base + GPIOIS);
 184
 185         gpioibe = readb(chip->base + GPIOIBE);
 186         if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
 187                 gpioibe |= 1 << offset;
 188         else {
 189                 gpioibe &= ~(1 << offset);
 190                 if (trigger & IRQ_TYPE_EDGE_RISING)
 191                         gpioiev |= 1 << offset;
 192                 else if (trigger & IRQ_TYPE_EDGE_FALLING)
 193                         gpioiev &= ~(1 << offset);
 194         }
 195         writeb(gpioibe, chip->base + GPIOIBE);
 196
 197         writeb(gpioiev, chip->base + GPIOIEV);
 198
 199         spin_unlock_irqrestore(&chip->irq_lock, flags);
 200
 201         return 0;
 202 }
 203
 204 static struct irq_chip pl061_irqchip = {
 205         .name           = "GPIO",
 206         .enable         = pl061_irq_enable,
 207         .disable        = pl061_irq_disable,
 208         .set_type       = pl061_irq_type,
 209 };
 210
 211 static void pl061_irq_handler(unsigned irq, struct irq_desc *desc)
 212 {
 213         struct list_head *chip_list = get_irq_data(irq);
 214         struct list_head *ptr;
 215         struct pl061_gpio *chip;
 216
 217         desc->chip->ack(irq);
 218         list_for_each(ptr, chip_list) {
 219                 unsigned long pending;
 220                 int offset;
 221
 222                 chip = list_entry(ptr, struct pl061_gpio, list);
 223                 pending = readb(chip->base + GPIOMIS);
 224                 writeb(pending, chip->base + GPIOIC);
 225
 226                 if (pending == 0)
 227                         continue;
 228
 229                 for_each_set_bit(offset, &pending, PL061_GPIO_NR)
 230                         generic_handle_irq(pl061_to_irq(&chip->gc, offset));
 231         }
 232         desc->chip->unmask(irq);
 233 }
 234
 235 static int pl061_probe(struct amba_device *dev, struct amba_id *id)
 236 {
 237         struct pl061_platform_data *pdata;
 238         struct pl061_gpio *chip;
 239         struct list_head *chip_list;
 240         int ret, irq, i;
 241         static DECLARE_BITMAP(init_irq, NR_IRQS);
 242
 243         pdata = dev->dev.platform_data;
 244         if (pdata == NULL)
 245                 return -ENODEV;
 246
 247         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 248         if (chip == NULL)
 249                 return -ENOMEM;
 250
 251         if (!request_mem_region(dev->res.start,
 252                                 resource_size(&dev->res), "pl061")) {
 253                 ret = -EBUSY;
 254                 goto free_mem;
 255         }
 256
 257         chip->base = ioremap(dev->res.start, resource_size(&dev->res));
 258         if (chip->base == NULL) {
 259                 ret = -ENOMEM;
 260                 goto release_region;
 261         }
 262
 263         spin_lock_init(&chip->lock);
 264         spin_lock_init(&chip->irq_lock);
 265         INIT_LIST_HEAD(&chip->list);
 266
 267         chip->gc.direction_input = pl061_direction_input;
 268         chip->gc.direction_output = pl061_direction_output;
 269         chip->gc.get = pl061_get_value;
 270         chip->gc.set = pl061_set_value;
 271         chip->gc.to_irq = pl061_to_irq;
 272         chip->gc.base = pdata->gpio_base;
 273         chip->gc.ngpio = PL061_GPIO_NR;
 274         chip->gc.label = dev_name(&dev->dev);
 275         chip->gc.dev = &dev->dev;
 276         chip->gc.owner = THIS_MODULE;
 277
 278         chip->irq_base = pdata->irq_base;
 279
 280         ret = gpiochip_add(&chip->gc);
 281         if (ret)
 282                 goto iounmap;
 283
 284         /*
 285          * irq_chip support
 286          */
 287
 288         if (chip->irq_base == (unsigned) -1)
 289                 return 0;
 290
 291         writeb(0, chip->base + GPIOIE); /* disable irqs */
 292         irq = dev->irq[0];
 293         if (irq < 0) {
 294                 ret = -ENODEV;
 295                 goto iounmap;
 296         }
 297         set_irq_chained_handler(irq, pl061_irq_handler);
 298         if (!test_and_set_bit(irq, init_irq)) { /* list initialized? */
 299                 chip_list = kmalloc(sizeof(*chip_list), GFP_KERNEL);
 300                 if (chip_list == NULL) {
 301                         clear_bit(irq, init_irq);
 302                         ret = -ENOMEM;
 303                         goto iounmap;
 304                 }
 305                 INIT_LIST_HEAD(chip_list);
 306                 set_irq_data(irq, chip_list);
 307         } else
 308                 chip_list = get_irq_data(irq);
 309         list_add(&chip->list, chip_list);
 310
 311         for (i = 0; i < PL061_GPIO_NR; i++) {
 312                 if (pdata->directions & (1 << i))
 313                         pl061_direction_output(&chip->gc, i,
 314                                         pdata->values & (1 << i));
 315                 else
 316                         pl061_direction_input(&chip->gc, i);
 317
 318                 set_irq_chip(i+chip->irq_base, &pl061_irqchip);
 319                 set_irq_handler(i+chip->irq_base, handle_simple_irq);
 320                 set_irq_flags(i+chip->irq_base, IRQF_VALID);
 321                 set_irq_chip_data(i+chip->irq_base, chip);
 322         }
 323
 324         return 0;
 325
 326 iounmap:
 327         iounmap(chip->base);
 328 release_region:
 329         release_mem_region(dev->res.start, resource_size(&dev->res));
 330 free_mem:
 331         kfree(chip);
 332
 333         return ret;
 334 }
 335
 336 static struct amba_id pl061_ids[] = {
 337         {
 338                 .id     = 0x00041061,
 339                 .mask   = 0x000fffff,
 340         },
 341         { 0, 0 },
 342 };
 343
 344 static struct amba_driver pl061_gpio_driver = {
 345         .drv = {
 346                 .name   = "pl061_gpio",
 347         },
 348         .id_table       = pl061_ids,
 349         .probe          = pl061_probe,
 350 };
 351
 352 static int __init pl061_gpio_init(void)
 353 {
 354         return amba_driver_register(&pl061_gpio_driver);
 355 }
 356 subsys_initcall(pl061_gpio_init);
 357
 358 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 359 MODULE_DESCRIPTION("PL061 GPIO driver");
 360 MODULE_LICENSE("GPL");