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/module.h>
  20 #include <linux/bitops.h>
  21 #include <linux/gpio/driver.h>
  22 #include <linux/device.h>
  23 #include <linux/amba/bus.h>
  24 #include <linux/slab.h>
  25 #include <linux/pinctrl/consumer.h>
  26 #include <linux/pm.h>
  27
  28 #define GPIODIR 0x400
  29 #define GPIOIS  0x404
  30 #define GPIOIBE 0x408
  31 #define GPIOIEV 0x40C
  32 #define GPIOIE  0x410
  33 #define GPIORIS 0x414
  34 #define GPIOMIS 0x418
  35 #define GPIOIC  0x41C
  36
  37 #define PL061_GPIO_NR   8
  38
  39 #ifdef CONFIG_PM
  40 struct pl061_context_save_regs {
  41         u8 gpio_data;
  42         u8 gpio_dir;
  43         u8 gpio_is;
  44         u8 gpio_ibe;
  45         u8 gpio_iev;
  46         u8 gpio_ie;
  47 };
  48 #endif
  49
  50 struct pl061 {
  51         raw_spinlock_t          lock;
  52
  53         void __iomem            *base;
  54         struct gpio_chip        gc;
  55         struct irq_chip         irq_chip;
  56         int                     parent_irq;
  57
  58 #ifdef CONFIG_PM
  59         struct pl061_context_save_regs csave_regs;
  60 #endif
  61 };
  62
  63 static int pl061_get_direction(struct gpio_chip *gc, unsigned offset)
  64 {
  65         struct pl061 *pl061 = gpiochip_get_data(gc);
  66
  67         if (readb(pl061->base + GPIODIR) & BIT(offset))
  68                 return GPIO_LINE_DIRECTION_OUT;
  69
  70         return GPIO_LINE_DIRECTION_IN;
  71 }
  72
  73 static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
  74 {
  75         struct pl061 *pl061 = gpiochip_get_data(gc);
  76         unsigned long flags;
  77         unsigned char gpiodir;
  78
  79         raw_spin_lock_irqsave(&pl061->lock, flags);
  80         gpiodir = readb(pl061->base + GPIODIR);
  81         gpiodir &= ~(BIT(offset));
  82         writeb(gpiodir, pl061->base + GPIODIR);
  83         raw_spin_unlock_irqrestore(&pl061->lock, flags);
  84
  85         return 0;
  86 }
  87
  88 static int pl061_direction_output(struct gpio_chip *gc, unsigned offset,
  89                 int value)
  90 {
  91         struct pl061 *pl061 = gpiochip_get_data(gc);
  92         unsigned long flags;
  93         unsigned char gpiodir;
  94
  95         raw_spin_lock_irqsave(&pl061->lock, flags);
  96         writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
  97         gpiodir = readb(pl061->base + GPIODIR);
  98         gpiodir |= BIT(offset);
  99         writeb(gpiodir, pl061->base + GPIODIR);
 100
 101         /*
 102          * gpio value is set again, because pl061 doesn't allow to set value of
 103          * a gpio pin before configuring it in OUT mode.
 104          */
 105         writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
 106         raw_spin_unlock_irqrestore(&pl061->lock, flags);
 107
 108         return 0;
 109 }
 110
 111 static int pl061_get_value(struct gpio_chip *gc, unsigned offset)
 112 {
 113         struct pl061 *pl061 = gpiochip_get_data(gc);
 114
 115         return !!readb(pl061->base + (BIT(offset + 2)));
 116 }
 117
 118 static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
 119 {
 120         struct pl061 *pl061 = gpiochip_get_data(gc);
 121
 122         writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
 123 }
 124
 125 static int pl061_irq_type(struct irq_data *d, unsigned trigger)
 126 {
 127         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 128         struct pl061 *pl061 = gpiochip_get_data(gc);
 129         int offset = irqd_to_hwirq(d);
 130         unsigned long flags;
 131         u8 gpiois, gpioibe, gpioiev;
 132         u8 bit = BIT(offset);
 133
 134         if (offset < 0 || offset >= PL061_GPIO_NR)
 135                 return -EINVAL;
 136
 137         if ((trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) &&
 138             (trigger & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)))
 139         {
 140                 dev_err(gc->parent,
 141                         "trying to configure line %d for both level and edge "
 142                         "detection, choose one!\n",
 143                         offset);
 144                 return -EINVAL;
 145         }
 146
 147
 148         raw_spin_lock_irqsave(&pl061->lock, flags);
 149
 150         gpioiev = readb(pl061->base + GPIOIEV);
 151         gpiois = readb(pl061->base + GPIOIS);
 152         gpioibe = readb(pl061->base + GPIOIBE);
 153
 154         if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
 155                 bool polarity = trigger & IRQ_TYPE_LEVEL_HIGH;
 156
 157                 /* Disable edge detection */
 158                 gpioibe &= ~bit;
 159                 /* Enable level detection */
 160                 gpiois |= bit;
 161                 /* Select polarity */
 162                 if (polarity)
 163                         gpioiev |= bit;
 164                 else
 165                         gpioiev &= ~bit;
 166                 irq_set_handler_locked(d, handle_level_irq);
 167                 dev_dbg(gc->parent, "line %d: IRQ on %s level\n",
 168                         offset,
 169                         polarity ? "HIGH" : "LOW");
 170         } else if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
 171                 /* Disable level detection */
 172                 gpiois &= ~bit;
 173                 /* Select both edges, setting this makes GPIOEV be ignored */
 174                 gpioibe |= bit;
 175                 irq_set_handler_locked(d, handle_edge_irq);
 176                 dev_dbg(gc->parent, "line %d: IRQ on both edges\n", offset);
 177         } else if ((trigger & IRQ_TYPE_EDGE_RISING) ||
 178                    (trigger & IRQ_TYPE_EDGE_FALLING)) {
 179                 bool rising = trigger & IRQ_TYPE_EDGE_RISING;
 180
 181                 /* Disable level detection */
 182                 gpiois &= ~bit;
 183                 /* Clear detection on both edges */
 184                 gpioibe &= ~bit;
 185                 /* Select edge */
 186                 if (rising)
 187                         gpioiev |= bit;
 188                 else
 189                         gpioiev &= ~bit;
 190                 irq_set_handler_locked(d, handle_edge_irq);
 191                 dev_dbg(gc->parent, "line %d: IRQ on %s edge\n",
 192                         offset,
 193                         rising ? "RISING" : "FALLING");
 194         } else {
 195                 /* No trigger: disable everything */
 196                 gpiois &= ~bit;
 197                 gpioibe &= ~bit;
 198                 gpioiev &= ~bit;
 199                 irq_set_handler_locked(d, handle_bad_irq);
 200                 dev_warn(gc->parent, "no trigger selected for line %d\n",
 201                          offset);
 202         }
 203
 204         writeb(gpiois, pl061->base + GPIOIS);
 205         writeb(gpioibe, pl061->base + GPIOIBE);
 206         writeb(gpioiev, pl061->base + GPIOIEV);
 207
 208         raw_spin_unlock_irqrestore(&pl061->lock, flags);
 209
 210         return 0;
 211 }
 212
 213 static void pl061_irq_handler(struct irq_desc *desc)
 214 {
 215         unsigned long pending;
 216         int offset;
 217         struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 218         struct pl061 *pl061 = gpiochip_get_data(gc);
 219         struct irq_chip *irqchip = irq_desc_get_chip(desc);
 220
 221         chained_irq_enter(irqchip, desc);
 222
 223         pending = readb(pl061->base + GPIOMIS);
 224         if (pending) {
 225                 for_each_set_bit(offset, &pending, PL061_GPIO_NR)
 226                         generic_handle_irq(irq_find_mapping(gc->irq.domain,
 227                                                             offset));
 228         }
 229
 230         chained_irq_exit(irqchip, desc);
 231 }
 232
 233 static void pl061_irq_mask(struct irq_data *d)
 234 {
 235         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 236         struct pl061 *pl061 = gpiochip_get_data(gc);
 237         u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
 238         u8 gpioie;
 239
 240         raw_spin_lock(&pl061->lock);
 241         gpioie = readb(pl061->base + GPIOIE) & ~mask;
 242         writeb(gpioie, pl061->base + GPIOIE);
 243         raw_spin_unlock(&pl061->lock);
 244 }
 245
 246 static void pl061_irq_unmask(struct irq_data *d)
 247 {
 248         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 249         struct pl061 *pl061 = gpiochip_get_data(gc);
 250         u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
 251         u8 gpioie;
 252
 253         raw_spin_lock(&pl061->lock);
 254         gpioie = readb(pl061->base + GPIOIE) | mask;
 255         writeb(gpioie, pl061->base + GPIOIE);
 256         raw_spin_unlock(&pl061->lock);
 257 }
 258
 259 /**
 260  * pl061_irq_ack() - ACK an edge IRQ
 261  * @d: IRQ data for this IRQ
 262  *
 263  * This gets called from the edge IRQ handler to ACK the edge IRQ
 264  * in the GPIOIC (interrupt-clear) register. For level IRQs this is
 265  * not needed: these go away when the level signal goes away.
 266  */
 267 static void pl061_irq_ack(struct irq_data *d)
 268 {
 269         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 270         struct pl061 *pl061 = gpiochip_get_data(gc);
 271         u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
 272
 273         raw_spin_lock(&pl061->lock);
 274         writeb(mask, pl061->base + GPIOIC);
 275         raw_spin_unlock(&pl061->lock);
 276 }
 277
 278 static int pl061_irq_set_wake(struct irq_data *d, unsigned int state)
 279 {
 280         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 281         struct pl061 *pl061 = gpiochip_get_data(gc);
 282
 283         return irq_set_irq_wake(pl061->parent_irq, state);
 284 }
 285
 286 static int pl061_probe(struct amba_device *adev, const struct amba_id *id)
 287 {
 288         struct device *dev = &adev->dev;
 289         struct pl061 *pl061;
 290         struct gpio_irq_chip *girq;
 291         int ret, irq;
 292
 293         pl061 = devm_kzalloc(dev, sizeof(*pl061), GFP_KERNEL);
 294         if (pl061 == NULL)
 295                 return -ENOMEM;
 296
 297         pl061->base = devm_ioremap_resource(dev, &adev->res);
 298         if (IS_ERR(pl061->base))
 299                 return PTR_ERR(pl061->base);
 300
 301         raw_spin_lock_init(&pl061->lock);
 302         pl061->gc.request = gpiochip_generic_request;
 303         pl061->gc.free = gpiochip_generic_free;
 304         pl061->gc.base = -1;
 305         pl061->gc.get_direction = pl061_get_direction;
 306         pl061->gc.direction_input = pl061_direction_input;
 307         pl061->gc.direction_output = pl061_direction_output;
 308         pl061->gc.get = pl061_get_value;
 309         pl061->gc.set = pl061_set_value;
 310         pl061->gc.ngpio = PL061_GPIO_NR;
 311         pl061->gc.label = dev_name(dev);
 312         pl061->gc.parent = dev;
 313         pl061->gc.owner = THIS_MODULE;
 314
 315         /*
 316          * irq_chip support
 317          */
 318         pl061->irq_chip.name = dev_name(dev);
 319         pl061->irq_chip.irq_ack = pl061_irq_ack;
 320         pl061->irq_chip.irq_mask = pl061_irq_mask;
 321         pl061->irq_chip.irq_unmask = pl061_irq_unmask;
 322         pl061->irq_chip.irq_set_type = pl061_irq_type;
 323         pl061->irq_chip.irq_set_wake = pl061_irq_set_wake;
 324
 325         writeb(0, pl061->base + GPIOIE); /* disable irqs */
 326         irq = adev->irq[0];
 327         if (!irq)
 328                 dev_warn(&adev->dev, "IRQ support disabled\n");
 329         pl061->parent_irq = irq;
 330
 331         girq = &pl061->gc.irq;
 332         girq->chip = &pl061->irq_chip;
 333         girq->parent_handler = pl061_irq_handler;
 334         girq->num_parents = 1;
 335         girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents),
 336                                      GFP_KERNEL);
 337         if (!girq->parents)
 338                 return -ENOMEM;
 339         girq->parents[0] = irq;
 340         girq->default_type = IRQ_TYPE_NONE;
 341         girq->handler = handle_bad_irq;
 342
 343         ret = devm_gpiochip_add_data(dev, &pl061->gc, pl061);
 344         if (ret)
 345                 return ret;
 346
 347         amba_set_drvdata(adev, pl061);
 348         dev_info(dev, "PL061 GPIO chip registered\n");
 349
 350         return 0;
 351 }
 352
 353 #ifdef CONFIG_PM
 354 static int pl061_suspend(struct device *dev)
 355 {
 356         struct pl061 *pl061 = dev_get_drvdata(dev);
 357         int offset;
 358
 359         pl061->csave_regs.gpio_data = 0;
 360         pl061->csave_regs.gpio_dir = readb(pl061->base + GPIODIR);
 361         pl061->csave_regs.gpio_is = readb(pl061->base + GPIOIS);
 362         pl061->csave_regs.gpio_ibe = readb(pl061->base + GPIOIBE);
 363         pl061->csave_regs.gpio_iev = readb(pl061->base + GPIOIEV);
 364         pl061->csave_regs.gpio_ie = readb(pl061->base + GPIOIE);
 365
 366         for (offset = 0; offset < PL061_GPIO_NR; offset++) {
 367                 if (pl061->csave_regs.gpio_dir & (BIT(offset)))
 368                         pl061->csave_regs.gpio_data |=
 369                                 pl061_get_value(&pl061->gc, offset) << offset;
 370         }
 371
 372         return 0;
 373 }
 374
 375 static int pl061_resume(struct device *dev)
 376 {
 377         struct pl061 *pl061 = dev_get_drvdata(dev);
 378         int offset;
 379
 380         for (offset = 0; offset < PL061_GPIO_NR; offset++) {
 381                 if (pl061->csave_regs.gpio_dir & (BIT(offset)))
 382                         pl061_direction_output(&pl061->gc, offset,
 383                                         pl061->csave_regs.gpio_data &
 384                                         (BIT(offset)));
 385                 else
 386                         pl061_direction_input(&pl061->gc, offset);
 387         }
 388
 389         writeb(pl061->csave_regs.gpio_is, pl061->base + GPIOIS);
 390         writeb(pl061->csave_regs.gpio_ibe, pl061->base + GPIOIBE);
 391         writeb(pl061->csave_regs.gpio_iev, pl061->base + GPIOIEV);
 392         writeb(pl061->csave_regs.gpio_ie, pl061->base + GPIOIE);
 393
 394         return 0;
 395 }
 396
 397 static const struct dev_pm_ops pl061_dev_pm_ops = {
 398         .suspend = pl061_suspend,
 399         .resume = pl061_resume,
 400         .freeze = pl061_suspend,
 401         .restore = pl061_resume,
 402 };
 403 #endif
 404
 405 static const struct amba_id pl061_ids[] = {
 406         {
 407                 .id     = 0x00041061,
 408                 .mask   = 0x000fffff,
 409         },
 410         { 0, 0 },
 411 };
 412 MODULE_DEVICE_TABLE(amba, pl061_ids);
 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 module_amba_driver(pl061_gpio_driver);
 425
 426 MODULE_LICENSE("GPL v2");