linux/drivers/gpio/gpio-mpc8xxx.c
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   1/*
   2 * GPIOs on MPC512x/8349/8572/8610/QorIQ and compatible
   3 *
   4 * Copyright (C) 2008 Peter Korsgaard <jacmet@sunsite.dk>
   5 * Copyright (C) 2016 Freescale Semiconductor Inc.
   6 *
   7 * This file is licensed under the terms of the GNU General Public License
   8 * version 2.  This program is licensed "as is" without any warranty of any
   9 * kind, whether express or implied.
  10 */
  11
  12#include <linux/kernel.h>
  13#include <linux/init.h>
  14#include <linux/spinlock.h>
  15#include <linux/io.h>
  16#include <linux/of.h>
  17#include <linux/of_gpio.h>
  18#include <linux/of_address.h>
  19#include <linux/of_irq.h>
  20#include <linux/of_platform.h>
  21#include <linux/slab.h>
  22#include <linux/irq.h>
  23#include <linux/gpio/driver.h>
  24#include <linux/bitops.h>
  25
  26#define MPC8XXX_GPIO_PINS       32
  27
  28#define GPIO_DIR                0x00
  29#define GPIO_ODR                0x04
  30#define GPIO_DAT                0x08
  31#define GPIO_IER                0x0c
  32#define GPIO_IMR                0x10
  33#define GPIO_ICR                0x14
  34#define GPIO_ICR2               0x18
  35
  36struct mpc8xxx_gpio_chip {
  37        struct gpio_chip        gc;
  38        void __iomem *regs;
  39        raw_spinlock_t lock;
  40
  41        int (*direction_output)(struct gpio_chip *chip,
  42                                unsigned offset, int value);
  43
  44        struct irq_domain *irq;
  45        unsigned int irqn;
  46};
  47
  48/*
  49 * This hardware has a big endian bit assignment such that GPIO line 0 is
  50 * connected to bit 31, line 1 to bit 30 ... line 31 to bit 0.
  51 * This inline helper give the right bitmask for a certain line.
  52 */
  53static inline u32 mpc_pin2mask(unsigned int offset)
  54{
  55        return BIT(31 - offset);
  56}
  57
  58/* Workaround GPIO 1 errata on MPC8572/MPC8536. The status of GPIOs
  59 * defined as output cannot be determined by reading GPDAT register,
  60 * so we use shadow data register instead. The status of input pins
  61 * is determined by reading GPDAT register.
  62 */
  63static int mpc8572_gpio_get(struct gpio_chip *gc, unsigned int gpio)
  64{
  65        u32 val;
  66        struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
  67        u32 out_mask, out_shadow;
  68
  69        out_mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_DIR);
  70        val = gc->read_reg(mpc8xxx_gc->regs + GPIO_DAT) & ~out_mask;
  71        out_shadow = gc->bgpio_data & out_mask;
  72
  73        return !!((val | out_shadow) & mpc_pin2mask(gpio));
  74}
  75
  76static int mpc5121_gpio_dir_out(struct gpio_chip *gc,
  77                                unsigned int gpio, int val)
  78{
  79        struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
  80        /* GPIO 28..31 are input only on MPC5121 */
  81        if (gpio >= 28)
  82                return -EINVAL;
  83
  84        return mpc8xxx_gc->direction_output(gc, gpio, val);
  85}
  86
  87static int mpc5125_gpio_dir_out(struct gpio_chip *gc,
  88                                unsigned int gpio, int val)
  89{
  90        struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
  91        /* GPIO 0..3 are input only on MPC5125 */
  92        if (gpio <= 3)
  93                return -EINVAL;
  94
  95        return mpc8xxx_gc->direction_output(gc, gpio, val);
  96}
  97
  98static int mpc8xxx_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
  99{
 100        struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
 101
 102        if (mpc8xxx_gc->irq && offset < MPC8XXX_GPIO_PINS)
 103                return irq_create_mapping(mpc8xxx_gc->irq, offset);
 104        else
 105                return -ENXIO;
 106}
 107
 108static void mpc8xxx_gpio_irq_cascade(struct irq_desc *desc)
 109{
 110        struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_desc_get_handler_data(desc);
 111        struct irq_chip *chip = irq_desc_get_chip(desc);
 112        struct gpio_chip *gc = &mpc8xxx_gc->gc;
 113        unsigned int mask;
 114
 115        mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_IER)
 116                & gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR);
 117        if (mask)
 118                generic_handle_irq(irq_linear_revmap(mpc8xxx_gc->irq,
 119                                                     32 - ffs(mask)));
 120        if (chip->irq_eoi)
 121                chip->irq_eoi(&desc->irq_data);
 122}
 123
 124static void mpc8xxx_irq_unmask(struct irq_data *d)
 125{
 126        struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
 127        struct gpio_chip *gc = &mpc8xxx_gc->gc;
 128        unsigned long flags;
 129
 130        raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 131
 132        gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR,
 133                gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR)
 134                | mpc_pin2mask(irqd_to_hwirq(d)));
 135
 136        raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 137}
 138
 139static void mpc8xxx_irq_mask(struct irq_data *d)
 140{
 141        struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
 142        struct gpio_chip *gc = &mpc8xxx_gc->gc;
 143        unsigned long flags;
 144
 145        raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 146
 147        gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR,
 148                gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR)
 149                & ~mpc_pin2mask(irqd_to_hwirq(d)));
 150
 151        raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 152}
 153
 154static void mpc8xxx_irq_ack(struct irq_data *d)
 155{
 156        struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
 157        struct gpio_chip *gc = &mpc8xxx_gc->gc;
 158
 159        gc->write_reg(mpc8xxx_gc->regs + GPIO_IER,
 160                      mpc_pin2mask(irqd_to_hwirq(d)));
 161}
 162
 163static int mpc8xxx_irq_set_type(struct irq_data *d, unsigned int flow_type)
 164{
 165        struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
 166        struct gpio_chip *gc = &mpc8xxx_gc->gc;
 167        unsigned long flags;
 168
 169        switch (flow_type) {
 170        case IRQ_TYPE_EDGE_FALLING:
 171                raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 172                gc->write_reg(mpc8xxx_gc->regs + GPIO_ICR,
 173                        gc->read_reg(mpc8xxx_gc->regs + GPIO_ICR)
 174                        | mpc_pin2mask(irqd_to_hwirq(d)));
 175                raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 176                break;
 177
 178        case IRQ_TYPE_EDGE_BOTH:
 179                raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 180                gc->write_reg(mpc8xxx_gc->regs + GPIO_ICR,
 181                        gc->read_reg(mpc8xxx_gc->regs + GPIO_ICR)
 182                        & ~mpc_pin2mask(irqd_to_hwirq(d)));
 183                raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 184                break;
 185
 186        default:
 187                return -EINVAL;
 188        }
 189
 190        return 0;
 191}
 192
 193static int mpc512x_irq_set_type(struct irq_data *d, unsigned int flow_type)
 194{
 195        struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
 196        struct gpio_chip *gc = &mpc8xxx_gc->gc;
 197        unsigned long gpio = irqd_to_hwirq(d);
 198        void __iomem *reg;
 199        unsigned int shift;
 200        unsigned long flags;
 201
 202        if (gpio < 16) {
 203                reg = mpc8xxx_gc->regs + GPIO_ICR;
 204                shift = (15 - gpio) * 2;
 205        } else {
 206                reg = mpc8xxx_gc->regs + GPIO_ICR2;
 207                shift = (15 - (gpio % 16)) * 2;
 208        }
 209
 210        switch (flow_type) {
 211        case IRQ_TYPE_EDGE_FALLING:
 212        case IRQ_TYPE_LEVEL_LOW:
 213                raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 214                gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift))
 215                        | (2 << shift));
 216                raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 217                break;
 218
 219        case IRQ_TYPE_EDGE_RISING:
 220        case IRQ_TYPE_LEVEL_HIGH:
 221                raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 222                gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift))
 223                        | (1 << shift));
 224                raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 225                break;
 226
 227        case IRQ_TYPE_EDGE_BOTH:
 228                raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 229                gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift)));
 230                raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 231                break;
 232
 233        default:
 234                return -EINVAL;
 235        }
 236
 237        return 0;
 238}
 239
 240static struct irq_chip mpc8xxx_irq_chip = {
 241        .name           = "mpc8xxx-gpio",
 242        .irq_unmask     = mpc8xxx_irq_unmask,
 243        .irq_mask       = mpc8xxx_irq_mask,
 244        .irq_ack        = mpc8xxx_irq_ack,
 245        /* this might get overwritten in mpc8xxx_probe() */
 246        .irq_set_type   = mpc8xxx_irq_set_type,
 247};
 248
 249static int mpc8xxx_gpio_irq_map(struct irq_domain *h, unsigned int irq,
 250                                irq_hw_number_t hwirq)
 251{
 252        irq_set_chip_data(irq, h->host_data);
 253        irq_set_chip_and_handler(irq, &mpc8xxx_irq_chip, handle_edge_irq);
 254
 255        return 0;
 256}
 257
 258static const struct irq_domain_ops mpc8xxx_gpio_irq_ops = {
 259        .map    = mpc8xxx_gpio_irq_map,
 260        .xlate  = irq_domain_xlate_twocell,
 261};
 262
 263struct mpc8xxx_gpio_devtype {
 264        int (*gpio_dir_out)(struct gpio_chip *, unsigned int, int);
 265        int (*gpio_get)(struct gpio_chip *, unsigned int);
 266        int (*irq_set_type)(struct irq_data *, unsigned int);
 267};
 268
 269static const struct mpc8xxx_gpio_devtype mpc512x_gpio_devtype = {
 270        .gpio_dir_out = mpc5121_gpio_dir_out,
 271        .irq_set_type = mpc512x_irq_set_type,
 272};
 273
 274static const struct mpc8xxx_gpio_devtype mpc5125_gpio_devtype = {
 275        .gpio_dir_out = mpc5125_gpio_dir_out,
 276        .irq_set_type = mpc512x_irq_set_type,
 277};
 278
 279static const struct mpc8xxx_gpio_devtype mpc8572_gpio_devtype = {
 280        .gpio_get = mpc8572_gpio_get,
 281};
 282
 283static const struct mpc8xxx_gpio_devtype mpc8xxx_gpio_devtype_default = {
 284        .irq_set_type = mpc8xxx_irq_set_type,
 285};
 286
 287static const struct of_device_id mpc8xxx_gpio_ids[] = {
 288        { .compatible = "fsl,mpc8349-gpio", },
 289        { .compatible = "fsl,mpc8572-gpio", .data = &mpc8572_gpio_devtype, },
 290        { .compatible = "fsl,mpc8610-gpio", },
 291        { .compatible = "fsl,mpc5121-gpio", .data = &mpc512x_gpio_devtype, },
 292        { .compatible = "fsl,mpc5125-gpio", .data = &mpc5125_gpio_devtype, },
 293        { .compatible = "fsl,pq3-gpio",     },
 294        { .compatible = "fsl,qoriq-gpio",   },
 295        {}
 296};
 297
 298static int mpc8xxx_probe(struct platform_device *pdev)
 299{
 300        struct device_node *np = pdev->dev.of_node;
 301        struct mpc8xxx_gpio_chip *mpc8xxx_gc;
 302        struct gpio_chip        *gc;
 303        const struct mpc8xxx_gpio_devtype *devtype =
 304                of_device_get_match_data(&pdev->dev);
 305        int ret;
 306
 307        mpc8xxx_gc = devm_kzalloc(&pdev->dev, sizeof(*mpc8xxx_gc), GFP_KERNEL);
 308        if (!mpc8xxx_gc)
 309                return -ENOMEM;
 310
 311        platform_set_drvdata(pdev, mpc8xxx_gc);
 312
 313        raw_spin_lock_init(&mpc8xxx_gc->lock);
 314
 315        mpc8xxx_gc->regs = of_iomap(np, 0);
 316        if (!mpc8xxx_gc->regs)
 317                return -ENOMEM;
 318
 319        gc = &mpc8xxx_gc->gc;
 320
 321        if (of_property_read_bool(np, "little-endian")) {
 322                ret = bgpio_init(gc, &pdev->dev, 4,
 323                                 mpc8xxx_gc->regs + GPIO_DAT,
 324                                 NULL, NULL,
 325                                 mpc8xxx_gc->regs + GPIO_DIR, NULL,
 326                                 BGPIOF_BIG_ENDIAN);
 327                if (ret)
 328                        goto err;
 329                dev_dbg(&pdev->dev, "GPIO registers are LITTLE endian\n");
 330        } else {
 331                ret = bgpio_init(gc, &pdev->dev, 4,
 332                                 mpc8xxx_gc->regs + GPIO_DAT,
 333                                 NULL, NULL,
 334                                 mpc8xxx_gc->regs + GPIO_DIR, NULL,
 335                                 BGPIOF_BIG_ENDIAN
 336                                 | BGPIOF_BIG_ENDIAN_BYTE_ORDER);
 337                if (ret)
 338                        goto err;
 339                dev_dbg(&pdev->dev, "GPIO registers are BIG endian\n");
 340        }
 341
 342        mpc8xxx_gc->direction_output = gc->direction_output;
 343
 344        if (!devtype)
 345                devtype = &mpc8xxx_gpio_devtype_default;
 346
 347        /*
 348         * It's assumed that only a single type of gpio controller is available
 349         * on the current machine, so overwriting global data is fine.
 350         */
 351        mpc8xxx_irq_chip.irq_set_type = devtype->irq_set_type;
 352
 353        if (devtype->gpio_dir_out)
 354                gc->direction_output = devtype->gpio_dir_out;
 355        if (devtype->gpio_get)
 356                gc->get = devtype->gpio_get;
 357
 358        gc->to_irq = mpc8xxx_gpio_to_irq;
 359
 360        ret = gpiochip_add_data(gc, mpc8xxx_gc);
 361        if (ret) {
 362                pr_err("%pOF: GPIO chip registration failed with status %d\n",
 363                       np, ret);
 364                goto err;
 365        }
 366
 367        mpc8xxx_gc->irqn = irq_of_parse_and_map(np, 0);
 368        if (!mpc8xxx_gc->irqn)
 369                return 0;
 370
 371        mpc8xxx_gc->irq = irq_domain_add_linear(np, MPC8XXX_GPIO_PINS,
 372                                        &mpc8xxx_gpio_irq_ops, mpc8xxx_gc);
 373        if (!mpc8xxx_gc->irq)
 374                return 0;
 375
 376        /* ack and mask all irqs */
 377        gc->write_reg(mpc8xxx_gc->regs + GPIO_IER, 0xffffffff);
 378        gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR, 0);
 379
 380        irq_set_chained_handler_and_data(mpc8xxx_gc->irqn,
 381                                         mpc8xxx_gpio_irq_cascade, mpc8xxx_gc);
 382        return 0;
 383err:
 384        iounmap(mpc8xxx_gc->regs);
 385        return ret;
 386}
 387
 388static int mpc8xxx_remove(struct platform_device *pdev)
 389{
 390        struct mpc8xxx_gpio_chip *mpc8xxx_gc = platform_get_drvdata(pdev);
 391
 392        if (mpc8xxx_gc->irq) {
 393                irq_set_chained_handler_and_data(mpc8xxx_gc->irqn, NULL, NULL);
 394                irq_domain_remove(mpc8xxx_gc->irq);
 395        }
 396
 397        gpiochip_remove(&mpc8xxx_gc->gc);
 398        iounmap(mpc8xxx_gc->regs);
 399
 400        return 0;
 401}
 402
 403static struct platform_driver mpc8xxx_plat_driver = {
 404        .probe          = mpc8xxx_probe,
 405        .remove         = mpc8xxx_remove,
 406        .driver         = {
 407                .name = "gpio-mpc8xxx",
 408                .of_match_table = mpc8xxx_gpio_ids,
 409        },
 410};
 411
 412static int __init mpc8xxx_init(void)
 413{
 414        return platform_driver_register(&mpc8xxx_plat_driver);
 415}
 416
 417arch_initcall(mpc8xxx_init);
 418