drivers/gpio/gpio-pl061.c

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