root/drivers/gpio/gpio-ep93xx.c

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DEFINITIONS

This source file includes following definitions.
  1. ep93xx_gpio_update_int_params
  2. ep93xx_gpio_port
  3. ep93xx_gpio_int_debounce
  4. ep93xx_gpio_ab_irq_handler
  5. ep93xx_gpio_f_irq_handler
  6. ep93xx_gpio_irq_ack
  7. ep93xx_gpio_irq_mask_ack
  8. ep93xx_gpio_irq_mask
  9. ep93xx_gpio_irq_unmask
  10. ep93xx_gpio_irq_type
  11. ep93xx_gpio_set_config
  12. ep93xx_gpio_f_to_irq
  13. ep93xx_gpio_add_bank
  14. ep93xx_gpio_probe
  15. ep93xx_gpio_init

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Generic EP93xx GPIO handling
   4  *
   5  * Copyright (c) 2008 Ryan Mallon
   6  * Copyright (c) 2011 H Hartley Sweeten <hsweeten@visionengravers.com>
   7  *
   8  * Based on code originally from:
   9  *  linux/arch/arm/mach-ep93xx/core.c
  10  */
  11 
  12 #include <linux/init.h>
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/io.h>
  16 #include <linux/irq.h>
  17 #include <linux/slab.h>
  18 #include <linux/gpio/driver.h>
  19 #include <linux/bitops.h>
  20 
  21 #define EP93XX_GPIO_F_INT_STATUS 0x5c
  22 #define EP93XX_GPIO_A_INT_STATUS 0xa0
  23 #define EP93XX_GPIO_B_INT_STATUS 0xbc
  24 
  25 /* Maximum value for gpio line identifiers */
  26 #define EP93XX_GPIO_LINE_MAX 63
  27 
  28 /* Maximum value for irq capable line identifiers */
  29 #define EP93XX_GPIO_LINE_MAX_IRQ 23
  30 
  31 /*
  32  * Static mapping of GPIO bank F IRQS:
  33  * F0..F7 (16..24) to irq 80..87.
  34  */
  35 #define EP93XX_GPIO_F_IRQ_BASE 80
  36 
  37 struct ep93xx_gpio {
  38         void __iomem            *base;
  39         struct gpio_chip        gc[8];
  40 };
  41 
  42 /*************************************************************************
  43  * Interrupt handling for EP93xx on-chip GPIOs
  44  *************************************************************************/
  45 static unsigned char gpio_int_unmasked[3];
  46 static unsigned char gpio_int_enabled[3];
  47 static unsigned char gpio_int_type1[3];
  48 static unsigned char gpio_int_type2[3];
  49 static unsigned char gpio_int_debounce[3];
  50 
  51 /* Port ordering is: A B F */
  52 static const u8 int_type1_register_offset[3]    = { 0x90, 0xac, 0x4c };
  53 static const u8 int_type2_register_offset[3]    = { 0x94, 0xb0, 0x50 };
  54 static const u8 eoi_register_offset[3]          = { 0x98, 0xb4, 0x54 };
  55 static const u8 int_en_register_offset[3]       = { 0x9c, 0xb8, 0x58 };
  56 static const u8 int_debounce_register_offset[3] = { 0xa8, 0xc4, 0x64 };
  57 
  58 static void ep93xx_gpio_update_int_params(struct ep93xx_gpio *epg, unsigned port)
  59 {
  60         BUG_ON(port > 2);
  61 
  62         writeb_relaxed(0, epg->base + int_en_register_offset[port]);
  63 
  64         writeb_relaxed(gpio_int_type2[port],
  65                        epg->base + int_type2_register_offset[port]);
  66 
  67         writeb_relaxed(gpio_int_type1[port],
  68                        epg->base + int_type1_register_offset[port]);
  69 
  70         writeb(gpio_int_unmasked[port] & gpio_int_enabled[port],
  71                epg->base + int_en_register_offset[port]);
  72 }
  73 
  74 static int ep93xx_gpio_port(struct gpio_chip *gc)
  75 {
  76         struct ep93xx_gpio *epg = gpiochip_get_data(gc);
  77         int port = 0;
  78 
  79         while (port < ARRAY_SIZE(epg->gc) && gc != &epg->gc[port])
  80                 port++;
  81 
  82         /* This should not happen but is there as a last safeguard */
  83         if (port == ARRAY_SIZE(epg->gc)) {
  84                 pr_crit("can't find the GPIO port\n");
  85                 return 0;
  86         }
  87 
  88         return port;
  89 }
  90 
  91 static void ep93xx_gpio_int_debounce(struct gpio_chip *gc,
  92                                      unsigned int offset, bool enable)
  93 {
  94         struct ep93xx_gpio *epg = gpiochip_get_data(gc);
  95         int port = ep93xx_gpio_port(gc);
  96         int port_mask = BIT(offset);
  97 
  98         if (enable)
  99                 gpio_int_debounce[port] |= port_mask;
 100         else
 101                 gpio_int_debounce[port] &= ~port_mask;
 102 
 103         writeb(gpio_int_debounce[port],
 104                epg->base + int_debounce_register_offset[port]);
 105 }
 106 
 107 static void ep93xx_gpio_ab_irq_handler(struct irq_desc *desc)
 108 {
 109         struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 110         struct ep93xx_gpio *epg = gpiochip_get_data(gc);
 111         struct irq_chip *irqchip = irq_desc_get_chip(desc);
 112         unsigned long stat;
 113         int offset;
 114 
 115         chained_irq_enter(irqchip, desc);
 116 
 117         /*
 118          * Dispatch the IRQs to the irqdomain of each A and B
 119          * gpiochip irqdomains depending on what has fired.
 120          * The tricky part is that the IRQ line is shared
 121          * between bank A and B and each has their own gpiochip.
 122          */
 123         stat = readb(epg->base + EP93XX_GPIO_A_INT_STATUS);
 124         for_each_set_bit(offset, &stat, 8)
 125                 generic_handle_irq(irq_find_mapping(epg->gc[0].irq.domain,
 126                                                     offset));
 127 
 128         stat = readb(epg->base + EP93XX_GPIO_B_INT_STATUS);
 129         for_each_set_bit(offset, &stat, 8)
 130                 generic_handle_irq(irq_find_mapping(epg->gc[1].irq.domain,
 131                                                     offset));
 132 
 133         chained_irq_exit(irqchip, desc);
 134 }
 135 
 136 static void ep93xx_gpio_f_irq_handler(struct irq_desc *desc)
 137 {
 138         /*
 139          * map discontiguous hw irq range to continuous sw irq range:
 140          *
 141          *  IRQ_EP93XX_GPIO{0..7}MUX -> EP93XX_GPIO_LINE_F{0..7}
 142          */
 143         struct irq_chip *irqchip = irq_desc_get_chip(desc);
 144         unsigned int irq = irq_desc_get_irq(desc);
 145         int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */
 146         int gpio_irq = EP93XX_GPIO_F_IRQ_BASE + port_f_idx;
 147 
 148         chained_irq_enter(irqchip, desc);
 149         generic_handle_irq(gpio_irq);
 150         chained_irq_exit(irqchip, desc);
 151 }
 152 
 153 static void ep93xx_gpio_irq_ack(struct irq_data *d)
 154 {
 155         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 156         struct ep93xx_gpio *epg = gpiochip_get_data(gc);
 157         int port = ep93xx_gpio_port(gc);
 158         int port_mask = BIT(d->irq & 7);
 159 
 160         if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) {
 161                 gpio_int_type2[port] ^= port_mask; /* switch edge direction */
 162                 ep93xx_gpio_update_int_params(epg, port);
 163         }
 164 
 165         writeb(port_mask, epg->base + eoi_register_offset[port]);
 166 }
 167 
 168 static void ep93xx_gpio_irq_mask_ack(struct irq_data *d)
 169 {
 170         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 171         struct ep93xx_gpio *epg = gpiochip_get_data(gc);
 172         int port = ep93xx_gpio_port(gc);
 173         int port_mask = BIT(d->irq & 7);
 174 
 175         if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH)
 176                 gpio_int_type2[port] ^= port_mask; /* switch edge direction */
 177 
 178         gpio_int_unmasked[port] &= ~port_mask;
 179         ep93xx_gpio_update_int_params(epg, port);
 180 
 181         writeb(port_mask, epg->base + eoi_register_offset[port]);
 182 }
 183 
 184 static void ep93xx_gpio_irq_mask(struct irq_data *d)
 185 {
 186         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 187         struct ep93xx_gpio *epg = gpiochip_get_data(gc);
 188         int port = ep93xx_gpio_port(gc);
 189 
 190         gpio_int_unmasked[port] &= ~BIT(d->irq & 7);
 191         ep93xx_gpio_update_int_params(epg, port);
 192 }
 193 
 194 static void ep93xx_gpio_irq_unmask(struct irq_data *d)
 195 {
 196         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 197         struct ep93xx_gpio *epg = gpiochip_get_data(gc);
 198         int port = ep93xx_gpio_port(gc);
 199 
 200         gpio_int_unmasked[port] |= BIT(d->irq & 7);
 201         ep93xx_gpio_update_int_params(epg, port);
 202 }
 203 
 204 /*
 205  * gpio_int_type1 controls whether the interrupt is level (0) or
 206  * edge (1) triggered, while gpio_int_type2 controls whether it
 207  * triggers on low/falling (0) or high/rising (1).
 208  */
 209 static int ep93xx_gpio_irq_type(struct irq_data *d, unsigned int type)
 210 {
 211         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 212         struct ep93xx_gpio *epg = gpiochip_get_data(gc);
 213         int port = ep93xx_gpio_port(gc);
 214         int offset = d->irq & 7;
 215         int port_mask = BIT(offset);
 216         irq_flow_handler_t handler;
 217 
 218         gc->direction_input(gc, offset);
 219 
 220         switch (type) {
 221         case IRQ_TYPE_EDGE_RISING:
 222                 gpio_int_type1[port] |= port_mask;
 223                 gpio_int_type2[port] |= port_mask;
 224                 handler = handle_edge_irq;
 225                 break;
 226         case IRQ_TYPE_EDGE_FALLING:
 227                 gpio_int_type1[port] |= port_mask;
 228                 gpio_int_type2[port] &= ~port_mask;
 229                 handler = handle_edge_irq;
 230                 break;
 231         case IRQ_TYPE_LEVEL_HIGH:
 232                 gpio_int_type1[port] &= ~port_mask;
 233                 gpio_int_type2[port] |= port_mask;
 234                 handler = handle_level_irq;
 235                 break;
 236         case IRQ_TYPE_LEVEL_LOW:
 237                 gpio_int_type1[port] &= ~port_mask;
 238                 gpio_int_type2[port] &= ~port_mask;
 239                 handler = handle_level_irq;
 240                 break;
 241         case IRQ_TYPE_EDGE_BOTH:
 242                 gpio_int_type1[port] |= port_mask;
 243                 /* set initial polarity based on current input level */
 244                 if (gc->get(gc, offset))
 245                         gpio_int_type2[port] &= ~port_mask; /* falling */
 246                 else
 247                         gpio_int_type2[port] |= port_mask; /* rising */
 248                 handler = handle_edge_irq;
 249                 break;
 250         default:
 251                 return -EINVAL;
 252         }
 253 
 254         irq_set_handler_locked(d, handler);
 255 
 256         gpio_int_enabled[port] |= port_mask;
 257 
 258         ep93xx_gpio_update_int_params(epg, port);
 259 
 260         return 0;
 261 }
 262 
 263 static struct irq_chip ep93xx_gpio_irq_chip = {
 264         .name           = "GPIO",
 265         .irq_ack        = ep93xx_gpio_irq_ack,
 266         .irq_mask_ack   = ep93xx_gpio_irq_mask_ack,
 267         .irq_mask       = ep93xx_gpio_irq_mask,
 268         .irq_unmask     = ep93xx_gpio_irq_unmask,
 269         .irq_set_type   = ep93xx_gpio_irq_type,
 270 };
 271 
 272 /*************************************************************************
 273  * gpiolib interface for EP93xx on-chip GPIOs
 274  *************************************************************************/
 275 struct ep93xx_gpio_bank {
 276         const char      *label;
 277         int             data;
 278         int             dir;
 279         int             base;
 280         bool            has_irq;
 281         bool            has_hierarchical_irq;
 282         unsigned int    irq_base;
 283 };
 284 
 285 #define EP93XX_GPIO_BANK(_label, _data, _dir, _base, _has_irq, _has_hier, _irq_base) \
 286         {                                                       \
 287                 .label          = _label,                       \
 288                 .data           = _data,                        \
 289                 .dir            = _dir,                         \
 290                 .base           = _base,                        \
 291                 .has_irq        = _has_irq,                     \
 292                 .has_hierarchical_irq = _has_hier,              \
 293                 .irq_base       = _irq_base,                    \
 294         }
 295 
 296 static struct ep93xx_gpio_bank ep93xx_gpio_banks[] = {
 297         /* Bank A has 8 IRQs */
 298         EP93XX_GPIO_BANK("A", 0x00, 0x10, 0, true, false, 64),
 299         /* Bank B has 8 IRQs */
 300         EP93XX_GPIO_BANK("B", 0x04, 0x14, 8, true, false, 72),
 301         EP93XX_GPIO_BANK("C", 0x08, 0x18, 40, false, false, 0),
 302         EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24, false, false, 0),
 303         EP93XX_GPIO_BANK("E", 0x20, 0x24, 32, false, false, 0),
 304         /* Bank F has 8 IRQs */
 305         EP93XX_GPIO_BANK("F", 0x30, 0x34, 16, false, true, 0),
 306         EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48, false, false, 0),
 307         EP93XX_GPIO_BANK("H", 0x40, 0x44, 56, false, false, 0),
 308 };
 309 
 310 static int ep93xx_gpio_set_config(struct gpio_chip *gc, unsigned offset,
 311                                   unsigned long config)
 312 {
 313         u32 debounce;
 314 
 315         if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
 316                 return -ENOTSUPP;
 317 
 318         debounce = pinconf_to_config_argument(config);
 319         ep93xx_gpio_int_debounce(gc, offset, debounce ? true : false);
 320 
 321         return 0;
 322 }
 323 
 324 static int ep93xx_gpio_f_to_irq(struct gpio_chip *gc, unsigned offset)
 325 {
 326         return EP93XX_GPIO_F_IRQ_BASE + offset;
 327 }
 328 
 329 static int ep93xx_gpio_add_bank(struct gpio_chip *gc,
 330                                 struct platform_device *pdev,
 331                                 struct ep93xx_gpio *epg,
 332                                 struct ep93xx_gpio_bank *bank)
 333 {
 334         void __iomem *data = epg->base + bank->data;
 335         void __iomem *dir = epg->base + bank->dir;
 336         struct device *dev = &pdev->dev;
 337         struct gpio_irq_chip *girq;
 338         int err;
 339 
 340         err = bgpio_init(gc, dev, 1, data, NULL, NULL, dir, NULL, 0);
 341         if (err)
 342                 return err;
 343 
 344         gc->label = bank->label;
 345         gc->base = bank->base;
 346 
 347         girq = &gc->irq;
 348         if (bank->has_irq || bank->has_hierarchical_irq) {
 349                 gc->set_config = ep93xx_gpio_set_config;
 350                 girq->chip = &ep93xx_gpio_irq_chip;
 351         }
 352 
 353         if (bank->has_irq) {
 354                 int ab_parent_irq = platform_get_irq(pdev, 0);
 355 
 356                 girq->parent_handler = ep93xx_gpio_ab_irq_handler;
 357                 girq->num_parents = 1;
 358                 girq->parents = devm_kcalloc(dev, 1,
 359                                              sizeof(*girq->parents),
 360                                              GFP_KERNEL);
 361                 if (!girq->parents)
 362                         return -ENOMEM;
 363                 girq->default_type = IRQ_TYPE_NONE;
 364                 girq->handler = handle_level_irq;
 365                 girq->parents[0] = ab_parent_irq;
 366                 girq->first = bank->irq_base;
 367         }
 368 
 369         /* Only bank F has especially funky IRQ handling */
 370         if (bank->has_hierarchical_irq) {
 371                 int gpio_irq;
 372                 int i;
 373 
 374                 /*
 375                  * FIXME: convert this to use hierarchical IRQ support!
 376                  * this requires fixing the root irqchip to be hierarchial.
 377                  */
 378                 girq->parent_handler = ep93xx_gpio_f_irq_handler;
 379                 girq->num_parents = 8;
 380                 girq->parents = devm_kcalloc(dev, 8,
 381                                              sizeof(*girq->parents),
 382                                              GFP_KERNEL);
 383                 if (!girq->parents)
 384                         return -ENOMEM;
 385                 /* Pick resources 1..8 for these IRQs */
 386                 for (i = 1; i <= 8; i++)
 387                         girq->parents[i - 1] = platform_get_irq(pdev, i);
 388                 for (i = 0; i < 8; i++) {
 389                         gpio_irq = EP93XX_GPIO_F_IRQ_BASE + i;
 390                         irq_set_chip_data(gpio_irq, &epg->gc[5]);
 391                         irq_set_chip_and_handler(gpio_irq,
 392                                                  &ep93xx_gpio_irq_chip,
 393                                                  handle_level_irq);
 394                         irq_clear_status_flags(gpio_irq, IRQ_NOREQUEST);
 395                 }
 396                 girq->default_type = IRQ_TYPE_NONE;
 397                 girq->handler = handle_level_irq;
 398                 gc->to_irq = ep93xx_gpio_f_to_irq;
 399         }
 400 
 401         return devm_gpiochip_add_data(dev, gc, epg);
 402 }
 403 
 404 static int ep93xx_gpio_probe(struct platform_device *pdev)
 405 {
 406         struct ep93xx_gpio *epg;
 407         int i;
 408 
 409         epg = devm_kzalloc(&pdev->dev, sizeof(*epg), GFP_KERNEL);
 410         if (!epg)
 411                 return -ENOMEM;
 412 
 413         epg->base = devm_platform_ioremap_resource(pdev, 0);
 414         if (IS_ERR(epg->base))
 415                 return PTR_ERR(epg->base);
 416 
 417         for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
 418                 struct gpio_chip *gc = &epg->gc[i];
 419                 struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];
 420 
 421                 if (ep93xx_gpio_add_bank(gc, pdev, epg, bank))
 422                         dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
 423                                  bank->label);
 424         }
 425 
 426         return 0;
 427 }
 428 
 429 static struct platform_driver ep93xx_gpio_driver = {
 430         .driver         = {
 431                 .name   = "gpio-ep93xx",
 432         },
 433         .probe          = ep93xx_gpio_probe,
 434 };
 435 
 436 static int __init ep93xx_gpio_init(void)
 437 {
 438         return platform_driver_register(&ep93xx_gpio_driver);
 439 }
 440 postcore_initcall(ep93xx_gpio_init);
 441 
 442 MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com> "
 443                 "H Hartley Sweeten <hsweeten@visionengravers.com>");
 444 MODULE_DESCRIPTION("EP93XX GPIO driver");
 445 MODULE_LICENSE("GPL");

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