linux/drivers/gpio/gpio-mxc.c
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   1/*
   2 * MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
   3 * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
   4 *
   5 * Based on code from Freescale,
   6 * Copyright (C) 2004-2010 Freescale Semiconductor, Inc. All Rights Reserved.
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License
  10 * as published by the Free Software Foundation; either version 2
  11 * of the License, or (at your option) any later version.
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20 */
  21
  22#include <linux/err.h>
  23#include <linux/init.h>
  24#include <linux/interrupt.h>
  25#include <linux/io.h>
  26#include <linux/irq.h>
  27#include <linux/irqdomain.h>
  28#include <linux/irqchip/chained_irq.h>
  29#include <linux/platform_device.h>
  30#include <linux/slab.h>
  31#include <linux/gpio/driver.h>
  32/* FIXME: for gpio_get_value() replace this with direct register read */
  33#include <linux/gpio.h>
  34#include <linux/of.h>
  35#include <linux/of_device.h>
  36#include <linux/module.h>
  37#include <linux/bug.h>
  38
  39enum mxc_gpio_hwtype {
  40        IMX1_GPIO,      /* runs on i.mx1 */
  41        IMX21_GPIO,     /* runs on i.mx21 and i.mx27 */
  42        IMX31_GPIO,     /* runs on i.mx31 */
  43        IMX35_GPIO,     /* runs on all other i.mx */
  44};
  45
  46/* device type dependent stuff */
  47struct mxc_gpio_hwdata {
  48        unsigned dr_reg;
  49        unsigned gdir_reg;
  50        unsigned psr_reg;
  51        unsigned icr1_reg;
  52        unsigned icr2_reg;
  53        unsigned imr_reg;
  54        unsigned isr_reg;
  55        int edge_sel_reg;
  56        unsigned low_level;
  57        unsigned high_level;
  58        unsigned rise_edge;
  59        unsigned fall_edge;
  60};
  61
  62struct mxc_gpio_port {
  63        struct list_head node;
  64        void __iomem *base;
  65        int irq;
  66        int irq_high;
  67        struct irq_domain *domain;
  68        struct gpio_chip gc;
  69        u32 both_edges;
  70};
  71
  72static struct mxc_gpio_hwdata imx1_imx21_gpio_hwdata = {
  73        .dr_reg         = 0x1c,
  74        .gdir_reg       = 0x00,
  75        .psr_reg        = 0x24,
  76        .icr1_reg       = 0x28,
  77        .icr2_reg       = 0x2c,
  78        .imr_reg        = 0x30,
  79        .isr_reg        = 0x34,
  80        .edge_sel_reg   = -EINVAL,
  81        .low_level      = 0x03,
  82        .high_level     = 0x02,
  83        .rise_edge      = 0x00,
  84        .fall_edge      = 0x01,
  85};
  86
  87static struct mxc_gpio_hwdata imx31_gpio_hwdata = {
  88        .dr_reg         = 0x00,
  89        .gdir_reg       = 0x04,
  90        .psr_reg        = 0x08,
  91        .icr1_reg       = 0x0c,
  92        .icr2_reg       = 0x10,
  93        .imr_reg        = 0x14,
  94        .isr_reg        = 0x18,
  95        .edge_sel_reg   = -EINVAL,
  96        .low_level      = 0x00,
  97        .high_level     = 0x01,
  98        .rise_edge      = 0x02,
  99        .fall_edge      = 0x03,
 100};
 101
 102static struct mxc_gpio_hwdata imx35_gpio_hwdata = {
 103        .dr_reg         = 0x00,
 104        .gdir_reg       = 0x04,
 105        .psr_reg        = 0x08,
 106        .icr1_reg       = 0x0c,
 107        .icr2_reg       = 0x10,
 108        .imr_reg        = 0x14,
 109        .isr_reg        = 0x18,
 110        .edge_sel_reg   = 0x1c,
 111        .low_level      = 0x00,
 112        .high_level     = 0x01,
 113        .rise_edge      = 0x02,
 114        .fall_edge      = 0x03,
 115};
 116
 117static enum mxc_gpio_hwtype mxc_gpio_hwtype;
 118static struct mxc_gpio_hwdata *mxc_gpio_hwdata;
 119
 120#define GPIO_DR                 (mxc_gpio_hwdata->dr_reg)
 121#define GPIO_GDIR               (mxc_gpio_hwdata->gdir_reg)
 122#define GPIO_PSR                (mxc_gpio_hwdata->psr_reg)
 123#define GPIO_ICR1               (mxc_gpio_hwdata->icr1_reg)
 124#define GPIO_ICR2               (mxc_gpio_hwdata->icr2_reg)
 125#define GPIO_IMR                (mxc_gpio_hwdata->imr_reg)
 126#define GPIO_ISR                (mxc_gpio_hwdata->isr_reg)
 127#define GPIO_EDGE_SEL           (mxc_gpio_hwdata->edge_sel_reg)
 128
 129#define GPIO_INT_LOW_LEV        (mxc_gpio_hwdata->low_level)
 130#define GPIO_INT_HIGH_LEV       (mxc_gpio_hwdata->high_level)
 131#define GPIO_INT_RISE_EDGE      (mxc_gpio_hwdata->rise_edge)
 132#define GPIO_INT_FALL_EDGE      (mxc_gpio_hwdata->fall_edge)
 133#define GPIO_INT_BOTH_EDGES     0x4
 134
 135static const struct platform_device_id mxc_gpio_devtype[] = {
 136        {
 137                .name = "imx1-gpio",
 138                .driver_data = IMX1_GPIO,
 139        }, {
 140                .name = "imx21-gpio",
 141                .driver_data = IMX21_GPIO,
 142        }, {
 143                .name = "imx31-gpio",
 144                .driver_data = IMX31_GPIO,
 145        }, {
 146                .name = "imx35-gpio",
 147                .driver_data = IMX35_GPIO,
 148        }, {
 149                /* sentinel */
 150        }
 151};
 152
 153static const struct of_device_id mxc_gpio_dt_ids[] = {
 154        { .compatible = "fsl,imx1-gpio", .data = &mxc_gpio_devtype[IMX1_GPIO], },
 155        { .compatible = "fsl,imx21-gpio", .data = &mxc_gpio_devtype[IMX21_GPIO], },
 156        { .compatible = "fsl,imx31-gpio", .data = &mxc_gpio_devtype[IMX31_GPIO], },
 157        { .compatible = "fsl,imx35-gpio", .data = &mxc_gpio_devtype[IMX35_GPIO], },
 158        { /* sentinel */ }
 159};
 160
 161/*
 162 * MX2 has one interrupt *for all* gpio ports. The list is used
 163 * to save the references to all ports, so that mx2_gpio_irq_handler
 164 * can walk through all interrupt status registers.
 165 */
 166static LIST_HEAD(mxc_gpio_ports);
 167
 168/* Note: This driver assumes 32 GPIOs are handled in one register */
 169
 170static int gpio_set_irq_type(struct irq_data *d, u32 type)
 171{
 172        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 173        struct mxc_gpio_port *port = gc->private;
 174        u32 bit, val;
 175        u32 gpio_idx = d->hwirq;
 176        u32 gpio = port->gc.base + gpio_idx;
 177        int edge;
 178        void __iomem *reg = port->base;
 179
 180        port->both_edges &= ~(1 << gpio_idx);
 181        switch (type) {
 182        case IRQ_TYPE_EDGE_RISING:
 183                edge = GPIO_INT_RISE_EDGE;
 184                break;
 185        case IRQ_TYPE_EDGE_FALLING:
 186                edge = GPIO_INT_FALL_EDGE;
 187                break;
 188        case IRQ_TYPE_EDGE_BOTH:
 189                if (GPIO_EDGE_SEL >= 0) {
 190                        edge = GPIO_INT_BOTH_EDGES;
 191                } else {
 192                        val = gpio_get_value(gpio);
 193                        if (val) {
 194                                edge = GPIO_INT_LOW_LEV;
 195                                pr_debug("mxc: set GPIO %d to low trigger\n", gpio);
 196                        } else {
 197                                edge = GPIO_INT_HIGH_LEV;
 198                                pr_debug("mxc: set GPIO %d to high trigger\n", gpio);
 199                        }
 200                        port->both_edges |= 1 << gpio_idx;
 201                }
 202                break;
 203        case IRQ_TYPE_LEVEL_LOW:
 204                edge = GPIO_INT_LOW_LEV;
 205                break;
 206        case IRQ_TYPE_LEVEL_HIGH:
 207                edge = GPIO_INT_HIGH_LEV;
 208                break;
 209        default:
 210                return -EINVAL;
 211        }
 212
 213        if (GPIO_EDGE_SEL >= 0) {
 214                val = readl(port->base + GPIO_EDGE_SEL);
 215                if (edge == GPIO_INT_BOTH_EDGES)
 216                        writel(val | (1 << gpio_idx),
 217                                port->base + GPIO_EDGE_SEL);
 218                else
 219                        writel(val & ~(1 << gpio_idx),
 220                                port->base + GPIO_EDGE_SEL);
 221        }
 222
 223        if (edge != GPIO_INT_BOTH_EDGES) {
 224                reg += GPIO_ICR1 + ((gpio_idx & 0x10) >> 2); /* lower or upper register */
 225                bit = gpio_idx & 0xf;
 226                val = readl(reg) & ~(0x3 << (bit << 1));
 227                writel(val | (edge << (bit << 1)), reg);
 228        }
 229
 230        writel(1 << gpio_idx, port->base + GPIO_ISR);
 231
 232        return 0;
 233}
 234
 235static void mxc_flip_edge(struct mxc_gpio_port *port, u32 gpio)
 236{
 237        void __iomem *reg = port->base;
 238        u32 bit, val;
 239        int edge;
 240
 241        reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */
 242        bit = gpio & 0xf;
 243        val = readl(reg);
 244        edge = (val >> (bit << 1)) & 3;
 245        val &= ~(0x3 << (bit << 1));
 246        if (edge == GPIO_INT_HIGH_LEV) {
 247                edge = GPIO_INT_LOW_LEV;
 248                pr_debug("mxc: switch GPIO %d to low trigger\n", gpio);
 249        } else if (edge == GPIO_INT_LOW_LEV) {
 250                edge = GPIO_INT_HIGH_LEV;
 251                pr_debug("mxc: switch GPIO %d to high trigger\n", gpio);
 252        } else {
 253                pr_err("mxc: invalid configuration for GPIO %d: %x\n",
 254                       gpio, edge);
 255                return;
 256        }
 257        writel(val | (edge << (bit << 1)), reg);
 258}
 259
 260/* handle 32 interrupts in one status register */
 261static void mxc_gpio_irq_handler(struct mxc_gpio_port *port, u32 irq_stat)
 262{
 263        while (irq_stat != 0) {
 264                int irqoffset = fls(irq_stat) - 1;
 265
 266                if (port->both_edges & (1 << irqoffset))
 267                        mxc_flip_edge(port, irqoffset);
 268
 269                generic_handle_irq(irq_find_mapping(port->domain, irqoffset));
 270
 271                irq_stat &= ~(1 << irqoffset);
 272        }
 273}
 274
 275/* MX1 and MX3 has one interrupt *per* gpio port */
 276static void mx3_gpio_irq_handler(struct irq_desc *desc)
 277{
 278        u32 irq_stat;
 279        struct mxc_gpio_port *port = irq_desc_get_handler_data(desc);
 280        struct irq_chip *chip = irq_desc_get_chip(desc);
 281
 282        chained_irq_enter(chip, desc);
 283
 284        irq_stat = readl(port->base + GPIO_ISR) & readl(port->base + GPIO_IMR);
 285
 286        mxc_gpio_irq_handler(port, irq_stat);
 287
 288        chained_irq_exit(chip, desc);
 289}
 290
 291/* MX2 has one interrupt *for all* gpio ports */
 292static void mx2_gpio_irq_handler(struct irq_desc *desc)
 293{
 294        u32 irq_msk, irq_stat;
 295        struct mxc_gpio_port *port;
 296        struct irq_chip *chip = irq_desc_get_chip(desc);
 297
 298        chained_irq_enter(chip, desc);
 299
 300        /* walk through all interrupt status registers */
 301        list_for_each_entry(port, &mxc_gpio_ports, node) {
 302                irq_msk = readl(port->base + GPIO_IMR);
 303                if (!irq_msk)
 304                        continue;
 305
 306                irq_stat = readl(port->base + GPIO_ISR) & irq_msk;
 307                if (irq_stat)
 308                        mxc_gpio_irq_handler(port, irq_stat);
 309        }
 310        chained_irq_exit(chip, desc);
 311}
 312
 313/*
 314 * Set interrupt number "irq" in the GPIO as a wake-up source.
 315 * While system is running, all registered GPIO interrupts need to have
 316 * wake-up enabled. When system is suspended, only selected GPIO interrupts
 317 * need to have wake-up enabled.
 318 * @param  irq          interrupt source number
 319 * @param  enable       enable as wake-up if equal to non-zero
 320 * @return       This function returns 0 on success.
 321 */
 322static int gpio_set_wake_irq(struct irq_data *d, u32 enable)
 323{
 324        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 325        struct mxc_gpio_port *port = gc->private;
 326        u32 gpio_idx = d->hwirq;
 327
 328        if (enable) {
 329                if (port->irq_high && (gpio_idx >= 16))
 330                        enable_irq_wake(port->irq_high);
 331                else
 332                        enable_irq_wake(port->irq);
 333        } else {
 334                if (port->irq_high && (gpio_idx >= 16))
 335                        disable_irq_wake(port->irq_high);
 336                else
 337                        disable_irq_wake(port->irq);
 338        }
 339
 340        return 0;
 341}
 342
 343static int mxc_gpio_init_gc(struct mxc_gpio_port *port, int irq_base)
 344{
 345        struct irq_chip_generic *gc;
 346        struct irq_chip_type *ct;
 347
 348        gc = irq_alloc_generic_chip("gpio-mxc", 1, irq_base,
 349                                    port->base, handle_level_irq);
 350        if (!gc)
 351                return -ENOMEM;
 352        gc->private = port;
 353
 354        ct = gc->chip_types;
 355        ct->chip.irq_ack = irq_gc_ack_set_bit;
 356        ct->chip.irq_mask = irq_gc_mask_clr_bit;
 357        ct->chip.irq_unmask = irq_gc_mask_set_bit;
 358        ct->chip.irq_set_type = gpio_set_irq_type;
 359        ct->chip.irq_set_wake = gpio_set_wake_irq;
 360        ct->chip.flags = IRQCHIP_MASK_ON_SUSPEND;
 361        ct->regs.ack = GPIO_ISR;
 362        ct->regs.mask = GPIO_IMR;
 363
 364        irq_setup_generic_chip(gc, IRQ_MSK(32), IRQ_GC_INIT_NESTED_LOCK,
 365                               IRQ_NOREQUEST, 0);
 366
 367        return 0;
 368}
 369
 370static void mxc_gpio_get_hw(struct platform_device *pdev)
 371{
 372        const struct of_device_id *of_id =
 373                        of_match_device(mxc_gpio_dt_ids, &pdev->dev);
 374        enum mxc_gpio_hwtype hwtype;
 375
 376        if (of_id)
 377                pdev->id_entry = of_id->data;
 378        hwtype = pdev->id_entry->driver_data;
 379
 380        if (mxc_gpio_hwtype) {
 381                /*
 382                 * The driver works with a reasonable presupposition,
 383                 * that is all gpio ports must be the same type when
 384                 * running on one soc.
 385                 */
 386                BUG_ON(mxc_gpio_hwtype != hwtype);
 387                return;
 388        }
 389
 390        if (hwtype == IMX35_GPIO)
 391                mxc_gpio_hwdata = &imx35_gpio_hwdata;
 392        else if (hwtype == IMX31_GPIO)
 393                mxc_gpio_hwdata = &imx31_gpio_hwdata;
 394        else
 395                mxc_gpio_hwdata = &imx1_imx21_gpio_hwdata;
 396
 397        mxc_gpio_hwtype = hwtype;
 398}
 399
 400static int mxc_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
 401{
 402        struct mxc_gpio_port *port = gpiochip_get_data(gc);
 403
 404        return irq_find_mapping(port->domain, offset);
 405}
 406
 407static int mxc_gpio_probe(struct platform_device *pdev)
 408{
 409        struct device_node *np = pdev->dev.of_node;
 410        struct mxc_gpio_port *port;
 411        struct resource *iores;
 412        int irq_base;
 413        int err;
 414
 415        mxc_gpio_get_hw(pdev);
 416
 417        port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
 418        if (!port)
 419                return -ENOMEM;
 420
 421        iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 422        port->base = devm_ioremap_resource(&pdev->dev, iores);
 423        if (IS_ERR(port->base))
 424                return PTR_ERR(port->base);
 425
 426        port->irq_high = platform_get_irq(pdev, 1);
 427        port->irq = platform_get_irq(pdev, 0);
 428        if (port->irq < 0)
 429                return port->irq;
 430
 431        /* disable the interrupt and clear the status */
 432        writel(0, port->base + GPIO_IMR);
 433        writel(~0, port->base + GPIO_ISR);
 434
 435        if (mxc_gpio_hwtype == IMX21_GPIO) {
 436                /*
 437                 * Setup one handler for all GPIO interrupts. Actually setting
 438                 * the handler is needed only once, but doing it for every port
 439                 * is more robust and easier.
 440                 */
 441                irq_set_chained_handler(port->irq, mx2_gpio_irq_handler);
 442        } else {
 443                /* setup one handler for each entry */
 444                irq_set_chained_handler_and_data(port->irq,
 445                                                 mx3_gpio_irq_handler, port);
 446                if (port->irq_high > 0)
 447                        /* setup handler for GPIO 16 to 31 */
 448                        irq_set_chained_handler_and_data(port->irq_high,
 449                                                         mx3_gpio_irq_handler,
 450                                                         port);
 451        }
 452
 453        err = bgpio_init(&port->gc, &pdev->dev, 4,
 454                         port->base + GPIO_PSR,
 455                         port->base + GPIO_DR, NULL,
 456                         port->base + GPIO_GDIR, NULL,
 457                         BGPIOF_READ_OUTPUT_REG_SET);
 458        if (err)
 459                goto out_bgio;
 460
 461        port->gc.to_irq = mxc_gpio_to_irq;
 462        port->gc.base = (pdev->id < 0) ? of_alias_get_id(np, "gpio") * 32 :
 463                                             pdev->id * 32;
 464
 465        err = devm_gpiochip_add_data(&pdev->dev, &port->gc, port);
 466        if (err)
 467                goto out_bgio;
 468
 469        irq_base = irq_alloc_descs(-1, 0, 32, numa_node_id());
 470        if (irq_base < 0) {
 471                err = irq_base;
 472                goto out_bgio;
 473        }
 474
 475        port->domain = irq_domain_add_legacy(np, 32, irq_base, 0,
 476                                             &irq_domain_simple_ops, NULL);
 477        if (!port->domain) {
 478                err = -ENODEV;
 479                goto out_irqdesc_free;
 480        }
 481
 482        /* gpio-mxc can be a generic irq chip */
 483        err = mxc_gpio_init_gc(port, irq_base);
 484        if (err < 0)
 485                goto out_irqdomain_remove;
 486
 487        list_add_tail(&port->node, &mxc_gpio_ports);
 488
 489        return 0;
 490
 491out_irqdomain_remove:
 492        irq_domain_remove(port->domain);
 493out_irqdesc_free:
 494        irq_free_descs(irq_base, 32);
 495out_bgio:
 496        dev_info(&pdev->dev, "%s failed with errno %d\n", __func__, err);
 497        return err;
 498}
 499
 500static struct platform_driver mxc_gpio_driver = {
 501        .driver         = {
 502                .name   = "gpio-mxc",
 503                .of_match_table = mxc_gpio_dt_ids,
 504        },
 505        .probe          = mxc_gpio_probe,
 506        .id_table       = mxc_gpio_devtype,
 507};
 508
 509static int __init gpio_mxc_init(void)
 510{
 511        return platform_driver_register(&mxc_gpio_driver);
 512}
 513postcore_initcall(gpio_mxc_init);
 514
 515MODULE_AUTHOR("Freescale Semiconductor, "
 516              "Daniel Mack <danielncaiaq.de>, "
 517              "Juergen Beisert <kernel@pengutronix.de>");
 518MODULE_DESCRIPTION("Freescale MXC GPIO");
 519MODULE_LICENSE("GPL");
 520