linux/drivers/gpio/gpio-em.c
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   1/*
   2 * Emma Mobile GPIO Support - GIO
   3 *
   4 *  Copyright (C) 2012 Magnus Damm
   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 as published by
   8 * the Free Software Foundation; either version 2 of the License
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 * GNU General Public License for more details.
  14 *
  15 * You should have received a copy of the GNU General Public License
  16 * along with this program; if not, write to the Free Software
  17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18 */
  19
  20#include <linux/init.h>
  21#include <linux/platform_device.h>
  22#include <linux/spinlock.h>
  23#include <linux/interrupt.h>
  24#include <linux/ioport.h>
  25#include <linux/io.h>
  26#include <linux/irq.h>
  27#include <linux/irqdomain.h>
  28#include <linux/bitops.h>
  29#include <linux/err.h>
  30#include <linux/gpio/driver.h>
  31#include <linux/slab.h>
  32#include <linux/module.h>
  33#include <linux/pinctrl/consumer.h>
  34
  35struct em_gio_priv {
  36        void __iomem *base0;
  37        void __iomem *base1;
  38        spinlock_t sense_lock;
  39        struct platform_device *pdev;
  40        struct gpio_chip gpio_chip;
  41        struct irq_chip irq_chip;
  42        struct irq_domain *irq_domain;
  43};
  44
  45#define GIO_E1 0x00
  46#define GIO_E0 0x04
  47#define GIO_EM 0x04
  48#define GIO_OL 0x08
  49#define GIO_OH 0x0c
  50#define GIO_I 0x10
  51#define GIO_IIA 0x14
  52#define GIO_IEN 0x18
  53#define GIO_IDS 0x1c
  54#define GIO_IIM 0x1c
  55#define GIO_RAW 0x20
  56#define GIO_MST 0x24
  57#define GIO_IIR 0x28
  58
  59#define GIO_IDT0 0x40
  60#define GIO_IDT1 0x44
  61#define GIO_IDT2 0x48
  62#define GIO_IDT3 0x4c
  63#define GIO_RAWBL 0x50
  64#define GIO_RAWBH 0x54
  65#define GIO_IRBL 0x58
  66#define GIO_IRBH 0x5c
  67
  68#define GIO_IDT(n) (GIO_IDT0 + ((n) * 4))
  69
  70static inline unsigned long em_gio_read(struct em_gio_priv *p, int offs)
  71{
  72        if (offs < GIO_IDT0)
  73                return ioread32(p->base0 + offs);
  74        else
  75                return ioread32(p->base1 + (offs - GIO_IDT0));
  76}
  77
  78static inline void em_gio_write(struct em_gio_priv *p, int offs,
  79                                unsigned long value)
  80{
  81        if (offs < GIO_IDT0)
  82                iowrite32(value, p->base0 + offs);
  83        else
  84                iowrite32(value, p->base1 + (offs - GIO_IDT0));
  85}
  86
  87static void em_gio_irq_disable(struct irq_data *d)
  88{
  89        struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
  90
  91        em_gio_write(p, GIO_IDS, BIT(irqd_to_hwirq(d)));
  92}
  93
  94static void em_gio_irq_enable(struct irq_data *d)
  95{
  96        struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
  97
  98        em_gio_write(p, GIO_IEN, BIT(irqd_to_hwirq(d)));
  99}
 100
 101static int em_gio_irq_reqres(struct irq_data *d)
 102{
 103        struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
 104        int ret;
 105
 106        ret = gpiochip_lock_as_irq(&p->gpio_chip, irqd_to_hwirq(d));
 107        if (ret) {
 108                dev_err(p->gpio_chip.parent,
 109                        "unable to lock HW IRQ %lu for IRQ\n",
 110                        irqd_to_hwirq(d));
 111                return ret;
 112        }
 113        return 0;
 114}
 115
 116static void em_gio_irq_relres(struct irq_data *d)
 117{
 118        struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
 119
 120        gpiochip_unlock_as_irq(&p->gpio_chip, irqd_to_hwirq(d));
 121}
 122
 123
 124#define GIO_ASYNC(x) (x + 8)
 125
 126static unsigned char em_gio_sense_table[IRQ_TYPE_SENSE_MASK + 1] = {
 127        [IRQ_TYPE_EDGE_RISING] = GIO_ASYNC(0x00),
 128        [IRQ_TYPE_EDGE_FALLING] = GIO_ASYNC(0x01),
 129        [IRQ_TYPE_LEVEL_HIGH] = GIO_ASYNC(0x02),
 130        [IRQ_TYPE_LEVEL_LOW] = GIO_ASYNC(0x03),
 131        [IRQ_TYPE_EDGE_BOTH] = GIO_ASYNC(0x04),
 132};
 133
 134static int em_gio_irq_set_type(struct irq_data *d, unsigned int type)
 135{
 136        unsigned char value = em_gio_sense_table[type & IRQ_TYPE_SENSE_MASK];
 137        struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
 138        unsigned int reg, offset, shift;
 139        unsigned long flags;
 140        unsigned long tmp;
 141
 142        if (!value)
 143                return -EINVAL;
 144
 145        offset = irqd_to_hwirq(d);
 146
 147        pr_debug("gio: sense irq = %d, mode = %d\n", offset, value);
 148
 149        /* 8 x 4 bit fields in 4 IDT registers */
 150        reg = GIO_IDT(offset >> 3);
 151        shift = (offset & 0x07) << 4;
 152
 153        spin_lock_irqsave(&p->sense_lock, flags);
 154
 155        /* disable the interrupt in IIA */
 156        tmp = em_gio_read(p, GIO_IIA);
 157        tmp &= ~BIT(offset);
 158        em_gio_write(p, GIO_IIA, tmp);
 159
 160        /* change the sense setting in IDT */
 161        tmp = em_gio_read(p, reg);
 162        tmp &= ~(0xf << shift);
 163        tmp |= value << shift;
 164        em_gio_write(p, reg, tmp);
 165
 166        /* clear pending interrupts */
 167        em_gio_write(p, GIO_IIR, BIT(offset));
 168
 169        /* enable the interrupt in IIA */
 170        tmp = em_gio_read(p, GIO_IIA);
 171        tmp |= BIT(offset);
 172        em_gio_write(p, GIO_IIA, tmp);
 173
 174        spin_unlock_irqrestore(&p->sense_lock, flags);
 175
 176        return 0;
 177}
 178
 179static irqreturn_t em_gio_irq_handler(int irq, void *dev_id)
 180{
 181        struct em_gio_priv *p = dev_id;
 182        unsigned long pending;
 183        unsigned int offset, irqs_handled = 0;
 184
 185        while ((pending = em_gio_read(p, GIO_MST))) {
 186                offset = __ffs(pending);
 187                em_gio_write(p, GIO_IIR, BIT(offset));
 188                generic_handle_irq(irq_find_mapping(p->irq_domain, offset));
 189                irqs_handled++;
 190        }
 191
 192        return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
 193}
 194
 195static inline struct em_gio_priv *gpio_to_priv(struct gpio_chip *chip)
 196{
 197        return gpiochip_get_data(chip);
 198}
 199
 200static int em_gio_direction_input(struct gpio_chip *chip, unsigned offset)
 201{
 202        em_gio_write(gpio_to_priv(chip), GIO_E0, BIT(offset));
 203        return 0;
 204}
 205
 206static int em_gio_get(struct gpio_chip *chip, unsigned offset)
 207{
 208        return !!(em_gio_read(gpio_to_priv(chip), GIO_I) & BIT(offset));
 209}
 210
 211static void __em_gio_set(struct gpio_chip *chip, unsigned int reg,
 212                         unsigned shift, int value)
 213{
 214        /* upper 16 bits contains mask and lower 16 actual value */
 215        em_gio_write(gpio_to_priv(chip), reg,
 216                     (BIT(shift + 16)) | (value << shift));
 217}
 218
 219static void em_gio_set(struct gpio_chip *chip, unsigned offset, int value)
 220{
 221        /* output is split into two registers */
 222        if (offset < 16)
 223                __em_gio_set(chip, GIO_OL, offset, value);
 224        else
 225                __em_gio_set(chip, GIO_OH, offset - 16, value);
 226}
 227
 228static int em_gio_direction_output(struct gpio_chip *chip, unsigned offset,
 229                                   int value)
 230{
 231        /* write GPIO value to output before selecting output mode of pin */
 232        em_gio_set(chip, offset, value);
 233        em_gio_write(gpio_to_priv(chip), GIO_E1, BIT(offset));
 234        return 0;
 235}
 236
 237static int em_gio_to_irq(struct gpio_chip *chip, unsigned offset)
 238{
 239        return irq_create_mapping(gpio_to_priv(chip)->irq_domain, offset);
 240}
 241
 242static int em_gio_request(struct gpio_chip *chip, unsigned offset)
 243{
 244        return pinctrl_gpio_request(chip->base + offset);
 245}
 246
 247static void em_gio_free(struct gpio_chip *chip, unsigned offset)
 248{
 249        pinctrl_gpio_free(chip->base + offset);
 250
 251        /* Set the GPIO as an input to ensure that the next GPIO request won't
 252        * drive the GPIO pin as an output.
 253        */
 254        em_gio_direction_input(chip, offset);
 255}
 256
 257static int em_gio_irq_domain_map(struct irq_domain *h, unsigned int irq,
 258                                 irq_hw_number_t hwirq)
 259{
 260        struct em_gio_priv *p = h->host_data;
 261
 262        pr_debug("gio: map hw irq = %d, irq = %d\n", (int)hwirq, irq);
 263
 264        irq_set_chip_data(irq, h->host_data);
 265        irq_set_chip_and_handler(irq, &p->irq_chip, handle_level_irq);
 266        return 0;
 267}
 268
 269static const struct irq_domain_ops em_gio_irq_domain_ops = {
 270        .map    = em_gio_irq_domain_map,
 271        .xlate  = irq_domain_xlate_twocell,
 272};
 273
 274static int em_gio_probe(struct platform_device *pdev)
 275{
 276        struct em_gio_priv *p;
 277        struct resource *io[2], *irq[2];
 278        struct gpio_chip *gpio_chip;
 279        struct irq_chip *irq_chip;
 280        const char *name = dev_name(&pdev->dev);
 281        unsigned int ngpios;
 282        int ret;
 283
 284        p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
 285        if (!p) {
 286                ret = -ENOMEM;
 287                goto err0;
 288        }
 289
 290        p->pdev = pdev;
 291        platform_set_drvdata(pdev, p);
 292        spin_lock_init(&p->sense_lock);
 293
 294        io[0] = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 295        io[1] = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 296        irq[0] = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 297        irq[1] = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
 298
 299        if (!io[0] || !io[1] || !irq[0] || !irq[1]) {
 300                dev_err(&pdev->dev, "missing IRQ or IOMEM\n");
 301                ret = -EINVAL;
 302                goto err0;
 303        }
 304
 305        p->base0 = devm_ioremap_nocache(&pdev->dev, io[0]->start,
 306                                        resource_size(io[0]));
 307        if (!p->base0) {
 308                dev_err(&pdev->dev, "failed to remap low I/O memory\n");
 309                ret = -ENXIO;
 310                goto err0;
 311        }
 312
 313        p->base1 = devm_ioremap_nocache(&pdev->dev, io[1]->start,
 314                                   resource_size(io[1]));
 315        if (!p->base1) {
 316                dev_err(&pdev->dev, "failed to remap high I/O memory\n");
 317                ret = -ENXIO;
 318                goto err0;
 319        }
 320
 321        if (of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios)) {
 322                dev_err(&pdev->dev, "Missing ngpios OF property\n");
 323                ret = -EINVAL;
 324                goto err0;
 325        }
 326
 327        gpio_chip = &p->gpio_chip;
 328        gpio_chip->of_node = pdev->dev.of_node;
 329        gpio_chip->direction_input = em_gio_direction_input;
 330        gpio_chip->get = em_gio_get;
 331        gpio_chip->direction_output = em_gio_direction_output;
 332        gpio_chip->set = em_gio_set;
 333        gpio_chip->to_irq = em_gio_to_irq;
 334        gpio_chip->request = em_gio_request;
 335        gpio_chip->free = em_gio_free;
 336        gpio_chip->label = name;
 337        gpio_chip->parent = &pdev->dev;
 338        gpio_chip->owner = THIS_MODULE;
 339        gpio_chip->base = -1;
 340        gpio_chip->ngpio = ngpios;
 341
 342        irq_chip = &p->irq_chip;
 343        irq_chip->name = name;
 344        irq_chip->irq_mask = em_gio_irq_disable;
 345        irq_chip->irq_unmask = em_gio_irq_enable;
 346        irq_chip->irq_set_type = em_gio_irq_set_type;
 347        irq_chip->irq_request_resources = em_gio_irq_reqres;
 348        irq_chip->irq_release_resources = em_gio_irq_relres;
 349        irq_chip->flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND;
 350
 351        p->irq_domain = irq_domain_add_simple(pdev->dev.of_node, ngpios, 0,
 352                                              &em_gio_irq_domain_ops, p);
 353        if (!p->irq_domain) {
 354                ret = -ENXIO;
 355                dev_err(&pdev->dev, "cannot initialize irq domain\n");
 356                goto err0;
 357        }
 358
 359        if (devm_request_irq(&pdev->dev, irq[0]->start,
 360                             em_gio_irq_handler, 0, name, p)) {
 361                dev_err(&pdev->dev, "failed to request low IRQ\n");
 362                ret = -ENOENT;
 363                goto err1;
 364        }
 365
 366        if (devm_request_irq(&pdev->dev, irq[1]->start,
 367                             em_gio_irq_handler, 0, name, p)) {
 368                dev_err(&pdev->dev, "failed to request high IRQ\n");
 369                ret = -ENOENT;
 370                goto err1;
 371        }
 372
 373        ret = gpiochip_add_data(gpio_chip, p);
 374        if (ret) {
 375                dev_err(&pdev->dev, "failed to add GPIO controller\n");
 376                goto err1;
 377        }
 378
 379        return 0;
 380
 381err1:
 382        irq_domain_remove(p->irq_domain);
 383err0:
 384        return ret;
 385}
 386
 387static int em_gio_remove(struct platform_device *pdev)
 388{
 389        struct em_gio_priv *p = platform_get_drvdata(pdev);
 390
 391        gpiochip_remove(&p->gpio_chip);
 392
 393        irq_domain_remove(p->irq_domain);
 394        return 0;
 395}
 396
 397static const struct of_device_id em_gio_dt_ids[] = {
 398        { .compatible = "renesas,em-gio", },
 399        {},
 400};
 401MODULE_DEVICE_TABLE(of, em_gio_dt_ids);
 402
 403static struct platform_driver em_gio_device_driver = {
 404        .probe          = em_gio_probe,
 405        .remove         = em_gio_remove,
 406        .driver         = {
 407                .name   = "em_gio",
 408                .of_match_table = em_gio_dt_ids,
 409        }
 410};
 411
 412static int __init em_gio_init(void)
 413{
 414        return platform_driver_register(&em_gio_device_driver);
 415}
 416postcore_initcall(em_gio_init);
 417
 418static void __exit em_gio_exit(void)
 419{
 420        platform_driver_unregister(&em_gio_device_driver);
 421}
 422module_exit(em_gio_exit);
 423
 424MODULE_AUTHOR("Magnus Damm");
 425MODULE_DESCRIPTION("Renesas Emma Mobile GIO Driver");
 426MODULE_LICENSE("GPL v2");
 427