linux/drivers/gpio/gpio-ep93xx.c
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   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
  37struct ep93xx_gpio {
  38        void __iomem            *base;
  39        struct gpio_chip        gc[8];
  40};
  41
  42/*************************************************************************
  43 * Interrupt handling for EP93xx on-chip GPIOs
  44 *************************************************************************/
  45static unsigned char gpio_int_unmasked[3];
  46static unsigned char gpio_int_enabled[3];
  47static unsigned char gpio_int_type1[3];
  48static unsigned char gpio_int_type2[3];
  49static unsigned char gpio_int_debounce[3];
  50
  51/* Port ordering is: A B F */
  52static const u8 int_type1_register_offset[3]    = { 0x90, 0xac, 0x4c };
  53static const u8 int_type2_register_offset[3]    = { 0x94, 0xb0, 0x50 };
  54static const u8 eoi_register_offset[3]          = { 0x98, 0xb4, 0x54 };
  55static const u8 int_en_register_offset[3]       = { 0x9c, 0xb8, 0x58 };
  56static const u8 int_debounce_register_offset[3] = { 0xa8, 0xc4, 0x64 };
  57
  58static 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
  74static 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
  91static 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
 107static 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
 136static 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
 153static 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
 168static 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
 184static 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
 194static 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 */
 209static 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
 263static 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 *************************************************************************/
 275struct 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
 296static 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
 310static 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
 324static int ep93xx_gpio_f_to_irq(struct gpio_chip *gc, unsigned offset)
 325{
 326        return EP93XX_GPIO_F_IRQ_BASE + offset;
 327}
 328
 329static 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
 404static 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
 429static struct platform_driver ep93xx_gpio_driver = {
 430        .driver         = {
 431                .name   = "gpio-ep93xx",
 432        },
 433        .probe          = ep93xx_gpio_probe,
 434};
 435
 436static int __init ep93xx_gpio_init(void)
 437{
 438        return platform_driver_register(&ep93xx_gpio_driver);
 439}
 440postcore_initcall(ep93xx_gpio_init);
 441
 442MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com> "
 443                "H Hartley Sweeten <hsweeten@visionengravers.com>");
 444MODULE_DESCRIPTION("EP93XX GPIO driver");
 445MODULE_LICENSE("GPL");
 446