drivers/gpio/gpio-pl061.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2008, 2009 Provigent Ltd.
   4  *
   5  * Author: Baruch Siach <baruch@tkos.co.il>
   6  *
   7  * Driver for the ARM PrimeCell(tm) General Purpose Input/Output (PL061)
   8  *
   9  * Data sheet: ARM DDI 0190B, September 2000
  10  */
  11 #include <linux/spinlock.h>
  12 #include <linux/errno.h>
  13 #include <linux/init.h>
  14 #include <linux/io.h>
  15 #include <linux/ioport.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/irq.h>
  18 #include <linux/irqchip/chained_irq.h>
  19 #include <linux/bitops.h>
  20 #include <linux/gpio/driver.h>
  21 #include <linux/device.h>
  22 #include <linux/amba/bus.h>
  23 #include <linux/slab.h>
  24 #include <linux/pinctrl/consumer.h>
  25 #include <linux/pm.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 #ifdef CONFIG_PM
  39 struct pl061_context_save_regs {
  40         u8 gpio_data;
  41         u8 gpio_dir;
  42         u8 gpio_is;
  43         u8 gpio_ibe;
  44         u8 gpio_iev;
  45         u8 gpio_ie;
  46 };
  47 #endif
  48
  49 struct pl061 {
  50         raw_spinlock_t          lock;
  51
  52         void __iomem            *base;
  53         struct gpio_chip        gc;
  54         struct irq_chip         irq_chip;
  55         int                     parent_irq;
  56
  57 #ifdef CONFIG_PM
  58         struct pl061_context_save_regs csave_regs;
  59 #endif
  60 };
  61
  62 static int pl061_get_direction(struct gpio_chip *gc, unsigned offset)
  63 {
  64         struct pl061 *pl061 = gpiochip_get_data(gc);
  65
  66         return !(readb(pl061->base + GPIODIR) & BIT(offset));
  67 }
  68
  69 static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
  70 {
  71         struct pl061 *pl061 = gpiochip_get_data(gc);
  72         unsigned long flags;
  73         unsigned char gpiodir;
  74
  75         raw_spin_lock_irqsave(&pl061->lock, flags);
  76         gpiodir = readb(pl061->base + GPIODIR);
  77         gpiodir &= ~(BIT(offset));
  78         writeb(gpiodir, pl061->base + GPIODIR);
  79         raw_spin_unlock_irqrestore(&pl061->lock, flags);
  80
  81         return 0;
  82 }
  83
  84 static int pl061_direction_output(struct gpio_chip *gc, unsigned offset,
  85                 int value)
  86 {
  87         struct pl061 *pl061 = gpiochip_get_data(gc);
  88         unsigned long flags;
  89         unsigned char gpiodir;
  90
  91         raw_spin_lock_irqsave(&pl061->lock, flags);
  92         writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
  93         gpiodir = readb(pl061->base + GPIODIR);
  94         gpiodir |= BIT(offset);
  95         writeb(gpiodir, pl061->base + GPIODIR);
  96
  97         /*
  98          * gpio value is set again, because pl061 doesn't allow to set value of
  99          * a gpio pin before configuring it in OUT mode.
 100          */
 101         writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
 102         raw_spin_unlock_irqrestore(&pl061->lock, flags);
 103
 104         return 0;
 105 }
 106
 107 static int pl061_get_value(struct gpio_chip *gc, unsigned offset)
 108 {
 109         struct pl061 *pl061 = gpiochip_get_data(gc);
 110
 111         return !!readb(pl061->base + (BIT(offset + 2)));
 112 }
 113
 114 static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
 115 {
 116         struct pl061 *pl061 = gpiochip_get_data(gc);
 117
 118         writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
 119 }
 120
 121 static int pl061_irq_type(struct irq_data *d, unsigned trigger)
 122 {
 123         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 124         struct pl061 *pl061 = gpiochip_get_data(gc);
 125         int offset = irqd_to_hwirq(d);
 126         unsigned long flags;
 127         u8 gpiois, gpioibe, gpioiev;
 128         u8 bit = BIT(offset);
 129
 130         if (offset < 0 || offset >= PL061_GPIO_NR)
 131                 return -EINVAL;
 132
 133         if ((trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) &&
 134             (trigger & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)))
 135         {
 136                 dev_err(gc->parent,
 137                         "trying to configure line %d for both level and edge "
 138                         "detection, choose one!\n",
 139                         offset);
 140                 return -EINVAL;
 141         }
 142
 143
 144         raw_spin_lock_irqsave(&pl061->lock, flags);
 145
 146         gpioiev = readb(pl061->base + GPIOIEV);
 147         gpiois = readb(pl061->base + GPIOIS);
 148         gpioibe = readb(pl061->base + GPIOIBE);
 149
 150         if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
 151                 bool polarity = trigger & IRQ_TYPE_LEVEL_HIGH;
 152
 153                 /* Disable edge detection */
 154                 gpioibe &= ~bit;
 155                 /* Enable level detection */
 156                 gpiois |= bit;
 157                 /* Select polarity */
 158                 if (polarity)
 159                         gpioiev |= bit;
 160                 else
 161                         gpioiev &= ~bit;
 162                 irq_set_handler_locked(d, handle_level_irq);
 163                 dev_dbg(gc->parent, "line %d: IRQ on %s level\n",
 164                         offset,
 165                         polarity ? "HIGH" : "LOW");
 166         } else if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
 167                 /* Disable level detection */
 168                 gpiois &= ~bit;
 169                 /* Select both edges, setting this makes GPIOEV be ignored */
 170                 gpioibe |= bit;
 171                 irq_set_handler_locked(d, handle_edge_irq);
 172                 dev_dbg(gc->parent, "line %d: IRQ on both edges\n", offset);
 173         } else if ((trigger & IRQ_TYPE_EDGE_RISING) ||
 174                    (trigger & IRQ_TYPE_EDGE_FALLING)) {
 175                 bool rising = trigger & IRQ_TYPE_EDGE_RISING;
 176
 177                 /* Disable level detection */
 178                 gpiois &= ~bit;
 179                 /* Clear detection on both edges */
 180                 gpioibe &= ~bit;
 181                 /* Select edge */
 182                 if (rising)
 183                         gpioiev |= bit;
 184                 else
 185                         gpioiev &= ~bit;
 186                 irq_set_handler_locked(d, handle_edge_irq);
 187                 dev_dbg(gc->parent, "line %d: IRQ on %s edge\n",
 188                         offset,
 189                         rising ? "RISING" : "FALLING");
 190         } else {
 191                 /* No trigger: disable everything */
 192                 gpiois &= ~bit;
 193                 gpioibe &= ~bit;
 194                 gpioiev &= ~bit;
 195                 irq_set_handler_locked(d, handle_bad_irq);
 196                 dev_warn(gc->parent, "no trigger selected for line %d\n",
 197                          offset);
 198         }
 199
 200         writeb(gpiois, pl061->base + GPIOIS);
 201         writeb(gpioibe, pl061->base + GPIOIBE);
 202         writeb(gpioiev, pl061->base + GPIOIEV);
 203
 204         raw_spin_unlock_irqrestore(&pl061->lock, flags);
 205
 206         return 0;
 207 }
 208
 209 static void pl061_irq_handler(struct irq_desc *desc)
 210 {
 211         unsigned long pending;
 212         int offset;
 213         struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 214         struct pl061 *pl061 = gpiochip_get_data(gc);
 215         struct irq_chip *irqchip = irq_desc_get_chip(desc);
 216
 217         chained_irq_enter(irqchip, desc);
 218
 219         pending = readb(pl061->base + GPIOMIS);
 220         if (pending) {
 221                 for_each_set_bit(offset, &pending, PL061_GPIO_NR)
 222                         generic_handle_irq(irq_find_mapping(gc->irq.domain,
 223                                                             offset));
 224         }
 225
 226         chained_irq_exit(irqchip, desc);
 227 }
 228
 229 static void pl061_irq_mask(struct irq_data *d)
 230 {
 231         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 232         struct pl061 *pl061 = gpiochip_get_data(gc);
 233         u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
 234         u8 gpioie;
 235
 236         raw_spin_lock(&pl061->lock);
 237         gpioie = readb(pl061->base + GPIOIE) & ~mask;
 238         writeb(gpioie, pl061->base + GPIOIE);
 239         raw_spin_unlock(&pl061->lock);
 240 }
 241
 242 static void pl061_irq_unmask(struct irq_data *d)
 243 {
 244         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 245         struct pl061 *pl061 = gpiochip_get_data(gc);
 246         u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
 247         u8 gpioie;
 248
 249         raw_spin_lock(&pl061->lock);
 250         gpioie = readb(pl061->base + GPIOIE) | mask;
 251         writeb(gpioie, pl061->base + GPIOIE);
 252         raw_spin_unlock(&pl061->lock);
 253 }
 254
 255 /**
 256  * pl061_irq_ack() - ACK an edge IRQ
 257  * @d: IRQ data for this IRQ
 258  *
 259  * This gets called from the edge IRQ handler to ACK the edge IRQ
 260  * in the GPIOIC (interrupt-clear) register. For level IRQs this is
 261  * not needed: these go away when the level signal goes away.
 262  */
 263 static void pl061_irq_ack(struct irq_data *d)
 264 {
 265         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 266         struct pl061 *pl061 = gpiochip_get_data(gc);
 267         u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
 268
 269         raw_spin_lock(&pl061->lock);
 270         writeb(mask, pl061->base + GPIOIC);
 271         raw_spin_unlock(&pl061->lock);
 272 }
 273
 274 static int pl061_irq_set_wake(struct irq_data *d, unsigned int state)
 275 {
 276         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 277         struct pl061 *pl061 = gpiochip_get_data(gc);
 278
 279         return irq_set_irq_wake(pl061->parent_irq, state);
 280 }
 281
 282 static int pl061_probe(struct amba_device *adev, const struct amba_id *id)
 283 {
 284         struct device *dev = &adev->dev;
 285         struct pl061 *pl061;
 286         struct gpio_irq_chip *girq;
 287         int ret, irq;
 288
 289         pl061 = devm_kzalloc(dev, sizeof(*pl061), GFP_KERNEL);
 290         if (pl061 == NULL)
 291                 return -ENOMEM;
 292
 293         pl061->base = devm_ioremap_resource(dev, &adev->res);
 294         if (IS_ERR(pl061->base))
 295                 return PTR_ERR(pl061->base);
 296
 297         raw_spin_lock_init(&pl061->lock);
 298         if (of_property_read_bool(dev->of_node, "gpio-ranges")) {
 299                 pl061->gc.request = gpiochip_generic_request;
 300                 pl061->gc.free = gpiochip_generic_free;
 301         }
 302
 303         pl061->gc.base = -1;
 304         pl061->gc.get_direction = pl061_get_direction;
 305         pl061->gc.direction_input = pl061_direction_input;
 306         pl061->gc.direction_output = pl061_direction_output;
 307         pl061->gc.get = pl061_get_value;
 308         pl061->gc.set = pl061_set_value;
 309         pl061->gc.ngpio = PL061_GPIO_NR;
 310         pl061->gc.label = dev_name(dev);
 311         pl061->gc.parent = dev;
 312         pl061->gc.owner = THIS_MODULE;
 313
 314         /*
 315          * irq_chip support
 316          */
 317         pl061->irq_chip.name = dev_name(dev);
 318         pl061->irq_chip.irq_ack = pl061_irq_ack;
 319         pl061->irq_chip.irq_mask = pl061_irq_mask;
 320         pl061->irq_chip.irq_unmask = pl061_irq_unmask;
 321         pl061->irq_chip.irq_set_type = pl061_irq_type;
 322         pl061->irq_chip.irq_set_wake = pl061_irq_set_wake;
 323
 324         writeb(0, pl061->base + GPIOIE); /* disable irqs */
 325         irq = adev->irq[0];
 326         if (irq < 0) {
 327                 dev_err(&adev->dev, "invalid IRQ\n");
 328                 return -ENODEV;
 329         }
 330         pl061->parent_irq = irq;
 331
 332         girq = &pl061->gc.irq;
 333         girq->chip = &pl061->irq_chip;
 334         girq->parent_handler = pl061_irq_handler;
 335         girq->num_parents = 1;
 336         girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents),
 337                                      GFP_KERNEL);
 338         if (!girq->parents)
 339                 return -ENOMEM;
 340         girq->parents[0] = irq;
 341         girq->default_type = IRQ_TYPE_NONE;
 342         girq->handler = handle_bad_irq;
 343
 344         ret = devm_gpiochip_add_data(dev, &pl061->gc, pl061);
 345         if (ret)
 346                 return ret;
 347
 348         amba_set_drvdata(adev, pl061);
 349         dev_info(dev, "PL061 GPIO chip registered\n");
 350
 351         return 0;
 352 }
 353
 354 #ifdef CONFIG_PM
 355 static int pl061_suspend(struct device *dev)
 356 {
 357         struct pl061 *pl061 = dev_get_drvdata(dev);
 358         int offset;
 359
 360         pl061->csave_regs.gpio_data = 0;
 361         pl061->csave_regs.gpio_dir = readb(pl061->base + GPIODIR);
 362         pl061->csave_regs.gpio_is = readb(pl061->base + GPIOIS);
 363         pl061->csave_regs.gpio_ibe = readb(pl061->base + GPIOIBE);
 364         pl061->csave_regs.gpio_iev = readb(pl061->base + GPIOIEV);
 365         pl061->csave_regs.gpio_ie = readb(pl061->base + GPIOIE);
 366
 367         for (offset = 0; offset < PL061_GPIO_NR; offset++) {
 368                 if (pl061->csave_regs.gpio_dir & (BIT(offset)))
 369                         pl061->csave_regs.gpio_data |=
 370                                 pl061_get_value(&pl061->gc, offset) << offset;
 371         }
 372
 373         return 0;
 374 }
 375
 376 static int pl061_resume(struct device *dev)
 377 {
 378         struct pl061 *pl061 = dev_get_drvdata(dev);
 379         int offset;
 380
 381         for (offset = 0; offset < PL061_GPIO_NR; offset++) {
 382                 if (pl061->csave_regs.gpio_dir & (BIT(offset)))
 383                         pl061_direction_output(&pl061->gc, offset,
 384                                         pl061->csave_regs.gpio_data &
 385                                         (BIT(offset)));
 386                 else
 387                         pl061_direction_input(&pl061->gc, offset);
 388         }
 389
 390         writeb(pl061->csave_regs.gpio_is, pl061->base + GPIOIS);
 391         writeb(pl061->csave_regs.gpio_ibe, pl061->base + GPIOIBE);
 392         writeb(pl061->csave_regs.gpio_iev, pl061->base + GPIOIEV);
 393         writeb(pl061->csave_regs.gpio_ie, pl061->base + GPIOIE);
 394
 395         return 0;
 396 }
 397
 398 static const struct dev_pm_ops pl061_dev_pm_ops = {
 399         .suspend = pl061_suspend,
 400         .resume = pl061_resume,
 401         .freeze = pl061_suspend,
 402         .restore = pl061_resume,
 403 };
 404 #endif
 405
 406 static const struct amba_id pl061_ids[] = {
 407         {
 408                 .id     = 0x00041061,
 409                 .mask   = 0x000fffff,
 410         },
 411         { 0, 0 },
 412 };
 413
 414 static struct amba_driver pl061_gpio_driver = {
 415         .drv = {
 416                 .name   = "pl061_gpio",
 417 #ifdef CONFIG_PM
 418                 .pm     = &pl061_dev_pm_ops,
 419 #endif
 420         },
 421         .id_table       = pl061_ids,
 422         .probe          = pl061_probe,
 423 };
 424
 425 static int __init pl061_gpio_init(void)
 426 {
 427         return amba_driver_register(&pl061_gpio_driver);
 428 }
 429 device_initcall(pl061_gpio_init);