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/io.h>
  16 #include <linux/ioport.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/irq.h>
  19 #include <linux/irqchip/chained_irq.h>
  20 #include <linux/bitops.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 #include <linux/pinctrl/consumer.h>
  27 #include <linux/pm.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 #ifdef CONFIG_PM
  41 struct pl061_context_save_regs {
  42         u8 gpio_data;
  43         u8 gpio_dir;
  44         u8 gpio_is;
  45         u8 gpio_ibe;
  46         u8 gpio_iev;
  47         u8 gpio_ie;
  48 };
  49 #endif
  50
  51 struct pl061_gpio {
  52         spinlock_t              lock;
  53
  54         void __iomem            *base;
  55         struct gpio_chip        gc;
  56
  57 #ifdef CONFIG_PM
  58         struct pl061_context_save_regs csave_regs;
  59 #endif
  60 };
  61
  62 static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
  63 {
  64         struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
  65         unsigned long flags;
  66         unsigned char gpiodir;
  67
  68         if (offset >= gc->ngpio)
  69                 return -EINVAL;
  70
  71         spin_lock_irqsave(&chip->lock, flags);
  72         gpiodir = readb(chip->base + GPIODIR);
  73         gpiodir &= ~(BIT(offset));
  74         writeb(gpiodir, chip->base + GPIODIR);
  75         spin_unlock_irqrestore(&chip->lock, flags);
  76
  77         return 0;
  78 }
  79
  80 static int pl061_direction_output(struct gpio_chip *gc, unsigned offset,
  81                 int value)
  82 {
  83         struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
  84         unsigned long flags;
  85         unsigned char gpiodir;
  86
  87         if (offset >= gc->ngpio)
  88                 return -EINVAL;
  89
  90         spin_lock_irqsave(&chip->lock, flags);
  91         writeb(!!value << offset, chip->base + (BIT(offset + 2)));
  92         gpiodir = readb(chip->base + GPIODIR);
  93         gpiodir |= BIT(offset);
  94         writeb(gpiodir, chip->base + GPIODIR);
  95
  96         /*
  97          * gpio value is set again, because pl061 doesn't allow to set value of
  98          * a gpio pin before configuring it in OUT mode.
  99          */
 100         writeb(!!value << offset, chip->base + (BIT(offset + 2)));
 101         spin_unlock_irqrestore(&chip->lock, flags);
 102
 103         return 0;
 104 }
 105
 106 static int pl061_get_value(struct gpio_chip *gc, unsigned offset)
 107 {
 108         struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
 109
 110         return !!readb(chip->base + (BIT(offset + 2)));
 111 }
 112
 113 static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
 114 {
 115         struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
 116
 117         writeb(!!value << offset, chip->base + (BIT(offset + 2)));
 118 }
 119
 120 static int pl061_irq_type(struct irq_data *d, unsigned trigger)
 121 {
 122         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 123         struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
 124         int offset = irqd_to_hwirq(d);
 125         unsigned long flags;
 126         u8 gpiois, gpioibe, gpioiev;
 127         u8 bit = BIT(offset);
 128
 129         if (offset < 0 || offset >= PL061_GPIO_NR)
 130                 return -EINVAL;
 131
 132         if ((trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) &&
 133             (trigger & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)))
 134         {
 135                 dev_err(gc->parent,
 136                         "trying to configure line %d for both level and edge "
 137                         "detection, choose one!\n",
 138                         offset);
 139                 return -EINVAL;
 140         }
 141
 142
 143         spin_lock_irqsave(&chip->lock, flags);
 144
 145         gpioiev = readb(chip->base + GPIOIEV);
 146         gpiois = readb(chip->base + GPIOIS);
 147         gpioibe = readb(chip->base + GPIOIBE);
 148
 149         if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
 150                 bool polarity = trigger & IRQ_TYPE_LEVEL_HIGH;
 151
 152                 /* Disable edge detection */
 153                 gpioibe &= ~bit;
 154                 /* Enable level detection */
 155                 gpiois |= bit;
 156                 /* Select polarity */
 157                 if (polarity)
 158                         gpioiev |= bit;
 159                 else
 160                         gpioiev &= ~bit;
 161                 irq_set_handler_locked(d, handle_level_irq);
 162                 dev_dbg(gc->parent, "line %d: IRQ on %s level\n",
 163                         offset,
 164                         polarity ? "HIGH" : "LOW");
 165         } else if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
 166                 /* Disable level detection */
 167                 gpiois &= ~bit;
 168                 /* Select both edges, setting this makes GPIOEV be ignored */
 169                 gpioibe |= bit;
 170                 irq_set_handler_locked(d, handle_edge_irq);
 171                 dev_dbg(gc->parent, "line %d: IRQ on both edges\n", offset);
 172         } else if ((trigger & IRQ_TYPE_EDGE_RISING) ||
 173                    (trigger & IRQ_TYPE_EDGE_FALLING)) {
 174                 bool rising = trigger & IRQ_TYPE_EDGE_RISING;
 175
 176                 /* Disable level detection */
 177                 gpiois &= ~bit;
 178                 /* Clear detection on both edges */
 179                 gpioibe &= ~bit;
 180                 /* Select edge */
 181                 if (rising)
 182                         gpioiev |= bit;
 183                 else
 184                         gpioiev &= ~bit;
 185                 irq_set_handler_locked(d, handle_edge_irq);
 186                 dev_dbg(gc->parent, "line %d: IRQ on %s edge\n",
 187                         offset,
 188                         rising ? "RISING" : "FALLING");
 189         } else {
 190                 /* No trigger: disable everything */
 191                 gpiois &= ~bit;
 192                 gpioibe &= ~bit;
 193                 gpioiev &= ~bit;
 194                 irq_set_handler_locked(d, handle_bad_irq);
 195                 dev_warn(gc->parent, "no trigger selected for line %d\n",
 196                          offset);
 197         }
 198
 199         writeb(gpiois, chip->base + GPIOIS);
 200         writeb(gpioibe, chip->base + GPIOIBE);
 201         writeb(gpioiev, chip->base + GPIOIEV);
 202
 203         spin_unlock_irqrestore(&chip->lock, flags);
 204
 205         return 0;
 206 }
 207
 208 static void pl061_irq_handler(struct irq_desc *desc)
 209 {
 210         unsigned long pending;
 211         int offset;
 212         struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 213         struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
 214         struct irq_chip *irqchip = irq_desc_get_chip(desc);
 215
 216         chained_irq_enter(irqchip, desc);
 217
 218         pending = readb(chip->base + GPIOMIS);
 219         if (pending) {
 220                 for_each_set_bit(offset, &pending, PL061_GPIO_NR)
 221                         generic_handle_irq(irq_find_mapping(gc->irqdomain,
 222                                                             offset));
 223         }
 224
 225         chained_irq_exit(irqchip, desc);
 226 }
 227
 228 static void pl061_irq_mask(struct irq_data *d)
 229 {
 230         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 231         struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
 232         u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
 233         u8 gpioie;
 234
 235         spin_lock(&chip->lock);
 236         gpioie = readb(chip->base + GPIOIE) & ~mask;
 237         writeb(gpioie, chip->base + GPIOIE);
 238         spin_unlock(&chip->lock);
 239 }
 240
 241 static void pl061_irq_unmask(struct irq_data *d)
 242 {
 243         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 244         struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
 245         u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
 246         u8 gpioie;
 247
 248         spin_lock(&chip->lock);
 249         gpioie = readb(chip->base + GPIOIE) | mask;
 250         writeb(gpioie, chip->base + GPIOIE);
 251         spin_unlock(&chip->lock);
 252 }
 253
 254 /**
 255  * pl061_irq_ack() - ACK an edge IRQ
 256  * @d: IRQ data for this IRQ
 257  *
 258  * This gets called from the edge IRQ handler to ACK the edge IRQ
 259  * in the GPIOIC (interrupt-clear) register. For level IRQs this is
 260  * not needed: these go away when the level signal goes away.
 261  */
 262 static void pl061_irq_ack(struct irq_data *d)
 263 {
 264         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 265         struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
 266         u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
 267
 268         spin_lock(&chip->lock);
 269         writeb(mask, chip->base + GPIOIC);
 270         spin_unlock(&chip->lock);
 271 }
 272
 273 static int pl061_irq_set_wake(struct irq_data *d, unsigned int state)
 274 {
 275         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 276
 277         return irq_set_irq_wake(gc->irq_parent, state);
 278 }
 279
 280 static struct irq_chip pl061_irqchip = {
 281         .name           = "pl061",
 282         .irq_ack        = pl061_irq_ack,
 283         .irq_mask       = pl061_irq_mask,
 284         .irq_unmask     = pl061_irq_unmask,
 285         .irq_set_type   = pl061_irq_type,
 286         .irq_set_wake   = pl061_irq_set_wake,
 287 };
 288
 289 static int pl061_probe(struct amba_device *adev, const struct amba_id *id)
 290 {
 291         struct device *dev = &adev->dev;
 292         struct pl061_platform_data *pdata = dev_get_platdata(dev);
 293         struct pl061_gpio *chip;
 294         int ret, irq, i, irq_base;
 295
 296         chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
 297         if (chip == NULL)
 298                 return -ENOMEM;
 299
 300         if (pdata) {
 301                 chip->gc.base = pdata->gpio_base;
 302                 irq_base = pdata->irq_base;
 303                 if (irq_base <= 0) {
 304                         dev_err(&adev->dev, "invalid IRQ base in pdata\n");
 305                         return -ENODEV;
 306                 }
 307         } else {
 308                 chip->gc.base = -1;
 309                 irq_base = 0;
 310         }
 311
 312         chip->base = devm_ioremap_resource(dev, &adev->res);
 313         if (IS_ERR(chip->base))
 314                 return PTR_ERR(chip->base);
 315
 316         spin_lock_init(&chip->lock);
 317         if (of_property_read_bool(dev->of_node, "gpio-ranges")) {
 318                 chip->gc.request = gpiochip_generic_request;
 319                 chip->gc.free = gpiochip_generic_free;
 320         }
 321
 322         chip->gc.direction_input = pl061_direction_input;
 323         chip->gc.direction_output = pl061_direction_output;
 324         chip->gc.get = pl061_get_value;
 325         chip->gc.set = pl061_set_value;
 326         chip->gc.ngpio = PL061_GPIO_NR;
 327         chip->gc.label = dev_name(dev);
 328         chip->gc.parent = dev;
 329         chip->gc.owner = THIS_MODULE;
 330
 331         ret = gpiochip_add(&chip->gc);
 332         if (ret)
 333                 return ret;
 334
 335         /*
 336          * irq_chip support
 337          */
 338         writeb(0, chip->base + GPIOIE); /* disable irqs */
 339         irq = adev->irq[0];
 340         if (irq < 0) {
 341                 dev_err(&adev->dev, "invalid IRQ\n");
 342                 return -ENODEV;
 343         }
 344
 345         ret = gpiochip_irqchip_add(&chip->gc, &pl061_irqchip,
 346                                    irq_base, handle_bad_irq,
 347                                    IRQ_TYPE_NONE);
 348         if (ret) {
 349                 dev_info(&adev->dev, "could not add irqchip\n");
 350                 return ret;
 351         }
 352         gpiochip_set_chained_irqchip(&chip->gc, &pl061_irqchip,
 353                                      irq, pl061_irq_handler);
 354
 355         for (i = 0; i < PL061_GPIO_NR; i++) {
 356                 if (pdata) {
 357                         if (pdata->directions & (BIT(i)))
 358                                 pl061_direction_output(&chip->gc, i,
 359                                                 pdata->values & (BIT(i)));
 360                         else
 361                                 pl061_direction_input(&chip->gc, i);
 362                 }
 363         }
 364
 365         amba_set_drvdata(adev, chip);
 366         dev_info(&adev->dev, "PL061 GPIO chip @%pa registered\n",
 367                  &adev->res.start);
 368
 369         return 0;
 370 }
 371
 372 #ifdef CONFIG_PM
 373 static int pl061_suspend(struct device *dev)
 374 {
 375         struct pl061_gpio *chip = dev_get_drvdata(dev);
 376         int offset;
 377
 378         chip->csave_regs.gpio_data = 0;
 379         chip->csave_regs.gpio_dir = readb(chip->base + GPIODIR);
 380         chip->csave_regs.gpio_is = readb(chip->base + GPIOIS);
 381         chip->csave_regs.gpio_ibe = readb(chip->base + GPIOIBE);
 382         chip->csave_regs.gpio_iev = readb(chip->base + GPIOIEV);
 383         chip->csave_regs.gpio_ie = readb(chip->base + GPIOIE);
 384
 385         for (offset = 0; offset < PL061_GPIO_NR; offset++) {
 386                 if (chip->csave_regs.gpio_dir & (BIT(offset)))
 387                         chip->csave_regs.gpio_data |=
 388                                 pl061_get_value(&chip->gc, offset) << offset;
 389         }
 390
 391         return 0;
 392 }
 393
 394 static int pl061_resume(struct device *dev)
 395 {
 396         struct pl061_gpio *chip = dev_get_drvdata(dev);
 397         int offset;
 398
 399         for (offset = 0; offset < PL061_GPIO_NR; offset++) {
 400                 if (chip->csave_regs.gpio_dir & (BIT(offset)))
 401                         pl061_direction_output(&chip->gc, offset,
 402                                         chip->csave_regs.gpio_data &
 403                                         (BIT(offset)));
 404                 else
 405                         pl061_direction_input(&chip->gc, offset);
 406         }
 407
 408         writeb(chip->csave_regs.gpio_is, chip->base + GPIOIS);
 409         writeb(chip->csave_regs.gpio_ibe, chip->base + GPIOIBE);
 410         writeb(chip->csave_regs.gpio_iev, chip->base + GPIOIEV);
 411         writeb(chip->csave_regs.gpio_ie, chip->base + GPIOIE);
 412
 413         return 0;
 414 }
 415
 416 static const struct dev_pm_ops pl061_dev_pm_ops = {
 417         .suspend = pl061_suspend,
 418         .resume = pl061_resume,
 419         .freeze = pl061_suspend,
 420         .restore = pl061_resume,
 421 };
 422 #endif
 423
 424 static struct amba_id pl061_ids[] = {
 425         {
 426                 .id     = 0x00041061,
 427                 .mask   = 0x000fffff,
 428         },
 429         { 0, 0 },
 430 };
 431
 432 MODULE_DEVICE_TABLE(amba, pl061_ids);
 433
 434 static struct amba_driver pl061_gpio_driver = {
 435         .drv = {
 436                 .name   = "pl061_gpio",
 437 #ifdef CONFIG_PM
 438                 .pm     = &pl061_dev_pm_ops,
 439 #endif
 440         },
 441         .id_table       = pl061_ids,
 442         .probe          = pl061_probe,
 443 };
 444
 445 static int __init pl061_gpio_init(void)
 446 {
 447         return amba_driver_register(&pl061_gpio_driver);
 448 }
 449 module_init(pl061_gpio_init);
 450
 451 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 452 MODULE_DESCRIPTION("PL061 GPIO driver");
 453 MODULE_LICENSE("GPL");