drivers/gpio/gpio-pl061.c

   1 /*
   2  * Copyright (C) 2008, 2009 Provigent Ltd.
   3  *
   4  * Author: Baruch Siach <baruch@tkos.co.il>
   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/init.h>
  17 #include <linux/io.h>
  18 #include <linux/ioport.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/irq.h>
  21 #include <linux/irqchip/chained_irq.h>
  22 #include <linux/bitops.h>
  23 #include <linux/gpio.h>
  24 #include <linux/device.h>
  25 #include <linux/amba/bus.h>
  26 #include <linux/slab.h>
  27 #include <linux/pinctrl/consumer.h>
  28 #include <linux/pm.h>
  29
  30 #define GPIODIR 0x400
  31 #define GPIOIS  0x404
  32 #define GPIOIBE 0x408
  33 #define GPIOIEV 0x40C
  34 #define GPIOIE  0x410
  35 #define GPIORIS 0x414
  36 #define GPIOMIS 0x418
  37 #define GPIOIC  0x41C
  38
  39 #define PL061_GPIO_NR   8
  40
  41 #ifdef CONFIG_PM
  42 struct pl061_context_save_regs {
  43         u8 gpio_data;
  44         u8 gpio_dir;
  45         u8 gpio_is;
  46         u8 gpio_ibe;
  47         u8 gpio_iev;
  48         u8 gpio_ie;
  49 };
  50 #endif
  51
  52 struct pl061 {
  53         raw_spinlock_t          lock;
  54
  55         void __iomem            *base;
  56         struct gpio_chip        gc;
  57         int                     parent_irq;
  58
  59 #ifdef CONFIG_PM
  60         struct pl061_context_save_regs csave_regs;
  61 #endif
  62 };
  63
  64 static int pl061_get_direction(struct gpio_chip *gc, unsigned offset)
  65 {
  66         struct pl061 *pl061 = gpiochip_get_data(gc);
  67
  68         return !(readb(pl061->base + GPIODIR) & BIT(offset));
  69 }
  70
  71 static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
  72 {
  73         struct pl061 *pl061 = gpiochip_get_data(gc);
  74         unsigned long flags;
  75         unsigned char gpiodir;
  76
  77         raw_spin_lock_irqsave(&pl061->lock, flags);
  78         gpiodir = readb(pl061->base + GPIODIR);
  79         gpiodir &= ~(BIT(offset));
  80         writeb(gpiodir, pl061->base + GPIODIR);
  81         raw_spin_unlock_irqrestore(&pl061->lock, flags);
  82
  83         return 0;
  84 }
  85
  86 static int pl061_direction_output(struct gpio_chip *gc, unsigned offset,
  87                 int value)
  88 {
  89         struct pl061 *pl061 = gpiochip_get_data(gc);
  90         unsigned long flags;
  91         unsigned char gpiodir;
  92
  93         raw_spin_lock_irqsave(&pl061->lock, flags);
  94         writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
  95         gpiodir = readb(pl061->base + GPIODIR);
  96         gpiodir |= BIT(offset);
  97         writeb(gpiodir, pl061->base + GPIODIR);
  98
  99         /*
 100          * gpio value is set again, because pl061 doesn't allow to set value of
 101          * a gpio pin before configuring it in OUT mode.
 102          */
 103         writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
 104         raw_spin_unlock_irqrestore(&pl061->lock, flags);
 105
 106         return 0;
 107 }
 108
 109 static int pl061_get_value(struct gpio_chip *gc, unsigned offset)
 110 {
 111         struct pl061 *pl061 = gpiochip_get_data(gc);
 112
 113         return !!readb(pl061->base + (BIT(offset + 2)));
 114 }
 115
 116 static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
 117 {
 118         struct pl061 *pl061 = gpiochip_get_data(gc);
 119
 120         writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
 121 }
 122
 123 static int pl061_irq_type(struct irq_data *d, unsigned trigger)
 124 {
 125         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 126         struct pl061 *pl061 = gpiochip_get_data(gc);
 127         int offset = irqd_to_hwirq(d);
 128         unsigned long flags;
 129         u8 gpiois, gpioibe, gpioiev;
 130         u8 bit = BIT(offset);
 131
 132         if (offset < 0 || offset >= PL061_GPIO_NR)
 133                 return -EINVAL;
 134
 135         if ((trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) &&
 136             (trigger & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)))
 137         {
 138                 dev_err(gc->parent,
 139                         "trying to configure line %d for both level and edge "
 140                         "detection, choose one!\n",
 141                         offset);
 142                 return -EINVAL;
 143         }
 144
 145
 146         raw_spin_lock_irqsave(&pl061->lock, flags);
 147
 148         gpioiev = readb(pl061->base + GPIOIEV);
 149         gpiois = readb(pl061->base + GPIOIS);
 150         gpioibe = readb(pl061->base + GPIOIBE);
 151
 152         if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
 153                 bool polarity = trigger & IRQ_TYPE_LEVEL_HIGH;
 154
 155                 /* Disable edge detection */
 156                 gpioibe &= ~bit;
 157                 /* Enable level detection */
 158                 gpiois |= bit;
 159                 /* Select polarity */
 160                 if (polarity)
 161                         gpioiev |= bit;
 162                 else
 163                         gpioiev &= ~bit;
 164                 irq_set_handler_locked(d, handle_level_irq);
 165                 dev_dbg(gc->parent, "line %d: IRQ on %s level\n",
 166                         offset,
 167                         polarity ? "HIGH" : "LOW");
 168         } else if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
 169                 /* Disable level detection */
 170                 gpiois &= ~bit;
 171                 /* Select both edges, setting this makes GPIOEV be ignored */
 172                 gpioibe |= bit;
 173                 irq_set_handler_locked(d, handle_edge_irq);
 174                 dev_dbg(gc->parent, "line %d: IRQ on both edges\n", offset);
 175         } else if ((trigger & IRQ_TYPE_EDGE_RISING) ||
 176                    (trigger & IRQ_TYPE_EDGE_FALLING)) {
 177                 bool rising = trigger & IRQ_TYPE_EDGE_RISING;
 178
 179                 /* Disable level detection */
 180                 gpiois &= ~bit;
 181                 /* Clear detection on both edges */
 182                 gpioibe &= ~bit;
 183                 /* Select edge */
 184                 if (rising)
 185                         gpioiev |= bit;
 186                 else
 187                         gpioiev &= ~bit;
 188                 irq_set_handler_locked(d, handle_edge_irq);
 189                 dev_dbg(gc->parent, "line %d: IRQ on %s edge\n",
 190                         offset,
 191                         rising ? "RISING" : "FALLING");
 192         } else {
 193                 /* No trigger: disable everything */
 194                 gpiois &= ~bit;
 195                 gpioibe &= ~bit;
 196                 gpioiev &= ~bit;
 197                 irq_set_handler_locked(d, handle_bad_irq);
 198                 dev_warn(gc->parent, "no trigger selected for line %d\n",
 199                          offset);
 200         }
 201
 202         writeb(gpiois, pl061->base + GPIOIS);
 203         writeb(gpioibe, pl061->base + GPIOIBE);
 204         writeb(gpioiev, pl061->base + GPIOIEV);
 205
 206         raw_spin_unlock_irqrestore(&pl061->lock, flags);
 207
 208         return 0;
 209 }
 210
 211 static void pl061_irq_handler(struct irq_desc *desc)
 212 {
 213         unsigned long pending;
 214         int offset;
 215         struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 216         struct pl061 *pl061 = gpiochip_get_data(gc);
 217         struct irq_chip *irqchip = irq_desc_get_chip(desc);
 218
 219         chained_irq_enter(irqchip, desc);
 220
 221         pending = readb(pl061->base + GPIOMIS);
 222         if (pending) {
 223                 for_each_set_bit(offset, &pending, PL061_GPIO_NR)
 224                         generic_handle_irq(irq_find_mapping(gc->irq.domain,
 225                                                             offset));
 226         }
 227
 228         chained_irq_exit(irqchip, desc);
 229 }
 230
 231 static void pl061_irq_mask(struct irq_data *d)
 232 {
 233         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 234         struct pl061 *pl061 = gpiochip_get_data(gc);
 235         u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
 236         u8 gpioie;
 237
 238         raw_spin_lock(&pl061->lock);
 239         gpioie = readb(pl061->base + GPIOIE) & ~mask;
 240         writeb(gpioie, pl061->base + GPIOIE);
 241         raw_spin_unlock(&pl061->lock);
 242 }
 243
 244 static void pl061_irq_unmask(struct irq_data *d)
 245 {
 246         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 247         struct pl061 *pl061 = gpiochip_get_data(gc);
 248         u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
 249         u8 gpioie;
 250
 251         raw_spin_lock(&pl061->lock);
 252         gpioie = readb(pl061->base + GPIOIE) | mask;
 253         writeb(gpioie, pl061->base + GPIOIE);
 254         raw_spin_unlock(&pl061->lock);
 255 }
 256
 257 /**
 258  * pl061_irq_ack() - ACK an edge IRQ
 259  * @d: IRQ data for this IRQ
 260  *
 261  * This gets called from the edge IRQ handler to ACK the edge IRQ
 262  * in the GPIOIC (interrupt-clear) register. For level IRQs this is
 263  * not needed: these go away when the level signal goes away.
 264  */
 265 static void pl061_irq_ack(struct irq_data *d)
 266 {
 267         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 268         struct pl061 *pl061 = gpiochip_get_data(gc);
 269         u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
 270
 271         raw_spin_lock(&pl061->lock);
 272         writeb(mask, pl061->base + GPIOIC);
 273         raw_spin_unlock(&pl061->lock);
 274 }
 275
 276 static int pl061_irq_set_wake(struct irq_data *d, unsigned int state)
 277 {
 278         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 279         struct pl061 *pl061 = gpiochip_get_data(gc);
 280
 281         return irq_set_irq_wake(pl061->parent_irq, state);
 282 }
 283
 284 static struct irq_chip pl061_irqchip = {
 285         .name           = "pl061",
 286         .irq_ack        = pl061_irq_ack,
 287         .irq_mask       = pl061_irq_mask,
 288         .irq_unmask     = pl061_irq_unmask,
 289         .irq_set_type   = pl061_irq_type,
 290         .irq_set_wake   = pl061_irq_set_wake,
 291 };
 292
 293 static int pl061_probe(struct amba_device *adev, const struct amba_id *id)
 294 {
 295         struct device *dev = &adev->dev;
 296         struct pl061 *pl061;
 297         int ret, irq;
 298
 299         pl061 = devm_kzalloc(dev, sizeof(*pl061), GFP_KERNEL);
 300         if (pl061 == NULL)
 301                 return -ENOMEM;
 302
 303         pl061->base = devm_ioremap_resource(dev, &adev->res);
 304         if (IS_ERR(pl061->base))
 305                 return PTR_ERR(pl061->base);
 306
 307         raw_spin_lock_init(&pl061->lock);
 308         if (of_property_read_bool(dev->of_node, "gpio-ranges")) {
 309                 pl061->gc.request = gpiochip_generic_request;
 310                 pl061->gc.free = gpiochip_generic_free;
 311         }
 312
 313         pl061->gc.base = -1;
 314         pl061->gc.get_direction = pl061_get_direction;
 315         pl061->gc.direction_input = pl061_direction_input;
 316         pl061->gc.direction_output = pl061_direction_output;
 317         pl061->gc.get = pl061_get_value;
 318         pl061->gc.set = pl061_set_value;
 319         pl061->gc.ngpio = PL061_GPIO_NR;
 320         pl061->gc.label = dev_name(dev);
 321         pl061->gc.parent = dev;
 322         pl061->gc.owner = THIS_MODULE;
 323
 324         ret = gpiochip_add_data(&pl061->gc, pl061);
 325         if (ret)
 326                 return ret;
 327
 328         /*
 329          * irq_chip support
 330          */
 331         writeb(0, pl061->base + GPIOIE); /* disable irqs */
 332         irq = adev->irq[0];
 333         if (irq < 0) {
 334                 dev_err(&adev->dev, "invalid IRQ\n");
 335                 return -ENODEV;
 336         }
 337         pl061->parent_irq = irq;
 338
 339         ret = gpiochip_irqchip_add(&pl061->gc, &pl061_irqchip,
 340                                    0, handle_bad_irq,
 341                                    IRQ_TYPE_NONE);
 342         if (ret) {
 343                 dev_info(&adev->dev, "could not add irqchip\n");
 344                 return ret;
 345         }
 346         gpiochip_set_chained_irqchip(&pl061->gc, &pl061_irqchip,
 347                                      irq, pl061_irq_handler);
 348
 349         amba_set_drvdata(adev, pl061);
 350         dev_info(&adev->dev, "PL061 GPIO chip @%pa registered\n",
 351                  &adev->res.start);
 352
 353         return 0;
 354 }
 355
 356 #ifdef CONFIG_PM
 357 static int pl061_suspend(struct device *dev)
 358 {
 359         struct pl061 *pl061 = dev_get_drvdata(dev);
 360         int offset;
 361
 362         pl061->csave_regs.gpio_data = 0;
 363         pl061->csave_regs.gpio_dir = readb(pl061->base + GPIODIR);
 364         pl061->csave_regs.gpio_is = readb(pl061->base + GPIOIS);
 365         pl061->csave_regs.gpio_ibe = readb(pl061->base + GPIOIBE);
 366         pl061->csave_regs.gpio_iev = readb(pl061->base + GPIOIEV);
 367         pl061->csave_regs.gpio_ie = readb(pl061->base + GPIOIE);
 368
 369         for (offset = 0; offset < PL061_GPIO_NR; offset++) {
 370                 if (pl061->csave_regs.gpio_dir & (BIT(offset)))
 371                         pl061->csave_regs.gpio_data |=
 372                                 pl061_get_value(&pl061->gc, offset) << offset;
 373         }
 374
 375         return 0;
 376 }
 377
 378 static int pl061_resume(struct device *dev)
 379 {
 380         struct pl061 *pl061 = dev_get_drvdata(dev);
 381         int offset;
 382
 383         for (offset = 0; offset < PL061_GPIO_NR; offset++) {
 384                 if (pl061->csave_regs.gpio_dir & (BIT(offset)))
 385                         pl061_direction_output(&pl061->gc, offset,
 386                                         pl061->csave_regs.gpio_data &
 387                                         (BIT(offset)));
 388                 else
 389                         pl061_direction_input(&pl061->gc, offset);
 390         }
 391
 392         writeb(pl061->csave_regs.gpio_is, pl061->base + GPIOIS);
 393         writeb(pl061->csave_regs.gpio_ibe, pl061->base + GPIOIBE);
 394         writeb(pl061->csave_regs.gpio_iev, pl061->base + GPIOIEV);
 395         writeb(pl061->csave_regs.gpio_ie, pl061->base + GPIOIE);
 396
 397         return 0;
 398 }
 399
 400 static const struct dev_pm_ops pl061_dev_pm_ops = {
 401         .suspend = pl061_suspend,
 402         .resume = pl061_resume,
 403         .freeze = pl061_suspend,
 404         .restore = pl061_resume,
 405 };
 406 #endif
 407
 408 static const struct amba_id pl061_ids[] = {
 409         {
 410                 .id     = 0x00041061,
 411                 .mask   = 0x000fffff,
 412         },
 413         { 0, 0 },
 414 };
 415
 416 static struct amba_driver pl061_gpio_driver = {
 417         .drv = {
 418                 .name   = "pl061_gpio",
 419 #ifdef CONFIG_PM
 420                 .pm     = &pl061_dev_pm_ops,
 421 #endif
 422         },
 423         .id_table       = pl061_ids,
 424         .probe          = pl061_probe,
 425 };
 426
 427 static int __init pl061_gpio_init(void)
 428 {
 429         return amba_driver_register(&pl061_gpio_driver);
 430 }
 431 device_initcall(pl061_gpio_init);