linux/drivers/gpio/gpio-lpc18xx.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * GPIO driver for NXP LPC18xx/43xx.
   4 *
   5 * Copyright (C) 2018 Vladimir Zapolskiy <vz@mleia.com>
   6 * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
   7 *
   8 */
   9
  10#include <linux/clk.h>
  11#include <linux/gpio/driver.h>
  12#include <linux/io.h>
  13#include <linux/irqdomain.h>
  14#include <linux/module.h>
  15#include <linux/of.h>
  16#include <linux/of_address.h>
  17#include <linux/of_gpio.h>
  18#include <linux/of_irq.h>
  19#include <linux/pinctrl/consumer.h>
  20#include <linux/platform_device.h>
  21
  22/* LPC18xx GPIO register offsets */
  23#define LPC18XX_REG_DIR(n)      (0x2000 + n * sizeof(u32))
  24
  25#define LPC18XX_MAX_PORTS       8
  26#define LPC18XX_PINS_PER_PORT   32
  27
  28/* LPC18xx GPIO pin interrupt controller register offsets */
  29#define LPC18XX_GPIO_PIN_IC_ISEL        0x00
  30#define LPC18XX_GPIO_PIN_IC_IENR        0x04
  31#define LPC18XX_GPIO_PIN_IC_SIENR       0x08
  32#define LPC18XX_GPIO_PIN_IC_CIENR       0x0c
  33#define LPC18XX_GPIO_PIN_IC_IENF        0x10
  34#define LPC18XX_GPIO_PIN_IC_SIENF       0x14
  35#define LPC18XX_GPIO_PIN_IC_CIENF       0x18
  36#define LPC18XX_GPIO_PIN_IC_RISE        0x1c
  37#define LPC18XX_GPIO_PIN_IC_FALL        0x20
  38#define LPC18XX_GPIO_PIN_IC_IST         0x24
  39
  40#define NR_LPC18XX_GPIO_PIN_IC_IRQS     8
  41
  42struct lpc18xx_gpio_pin_ic {
  43        void __iomem *base;
  44        struct irq_domain *domain;
  45        struct raw_spinlock lock;
  46};
  47
  48struct lpc18xx_gpio_chip {
  49        struct gpio_chip gpio;
  50        void __iomem *base;
  51        struct clk *clk;
  52        struct lpc18xx_gpio_pin_ic *pin_ic;
  53        spinlock_t lock;
  54};
  55
  56static inline void lpc18xx_gpio_pin_ic_isel(struct lpc18xx_gpio_pin_ic *ic,
  57                                            u32 pin, bool set)
  58{
  59        u32 val = readl_relaxed(ic->base + LPC18XX_GPIO_PIN_IC_ISEL);
  60
  61        if (set)
  62                val &= ~BIT(pin);
  63        else
  64                val |= BIT(pin);
  65
  66        writel_relaxed(val, ic->base + LPC18XX_GPIO_PIN_IC_ISEL);
  67}
  68
  69static inline void lpc18xx_gpio_pin_ic_set(struct lpc18xx_gpio_pin_ic *ic,
  70                                           u32 pin, u32 reg)
  71{
  72        writel_relaxed(BIT(pin), ic->base + reg);
  73}
  74
  75static void lpc18xx_gpio_pin_ic_mask(struct irq_data *d)
  76{
  77        struct lpc18xx_gpio_pin_ic *ic = d->chip_data;
  78        u32 type = irqd_get_trigger_type(d);
  79
  80        raw_spin_lock(&ic->lock);
  81
  82        if (type & IRQ_TYPE_LEVEL_MASK || type & IRQ_TYPE_EDGE_RISING)
  83                lpc18xx_gpio_pin_ic_set(ic, d->hwirq,
  84                                        LPC18XX_GPIO_PIN_IC_CIENR);
  85
  86        if (type & IRQ_TYPE_EDGE_FALLING)
  87                lpc18xx_gpio_pin_ic_set(ic, d->hwirq,
  88                                        LPC18XX_GPIO_PIN_IC_CIENF);
  89
  90        raw_spin_unlock(&ic->lock);
  91
  92        irq_chip_mask_parent(d);
  93}
  94
  95static void lpc18xx_gpio_pin_ic_unmask(struct irq_data *d)
  96{
  97        struct lpc18xx_gpio_pin_ic *ic = d->chip_data;
  98        u32 type = irqd_get_trigger_type(d);
  99
 100        raw_spin_lock(&ic->lock);
 101
 102        if (type & IRQ_TYPE_LEVEL_MASK || type & IRQ_TYPE_EDGE_RISING)
 103                lpc18xx_gpio_pin_ic_set(ic, d->hwirq,
 104                                        LPC18XX_GPIO_PIN_IC_SIENR);
 105
 106        if (type & IRQ_TYPE_EDGE_FALLING)
 107                lpc18xx_gpio_pin_ic_set(ic, d->hwirq,
 108                                        LPC18XX_GPIO_PIN_IC_SIENF);
 109
 110        raw_spin_unlock(&ic->lock);
 111
 112        irq_chip_unmask_parent(d);
 113}
 114
 115static void lpc18xx_gpio_pin_ic_eoi(struct irq_data *d)
 116{
 117        struct lpc18xx_gpio_pin_ic *ic = d->chip_data;
 118        u32 type = irqd_get_trigger_type(d);
 119
 120        raw_spin_lock(&ic->lock);
 121
 122        if (type & IRQ_TYPE_EDGE_BOTH)
 123                lpc18xx_gpio_pin_ic_set(ic, d->hwirq,
 124                                        LPC18XX_GPIO_PIN_IC_IST);
 125
 126        raw_spin_unlock(&ic->lock);
 127
 128        irq_chip_eoi_parent(d);
 129}
 130
 131static int lpc18xx_gpio_pin_ic_set_type(struct irq_data *d, unsigned int type)
 132{
 133        struct lpc18xx_gpio_pin_ic *ic = d->chip_data;
 134
 135        raw_spin_lock(&ic->lock);
 136
 137        if (type & IRQ_TYPE_LEVEL_HIGH) {
 138                lpc18xx_gpio_pin_ic_isel(ic, d->hwirq, true);
 139                lpc18xx_gpio_pin_ic_set(ic, d->hwirq,
 140                                        LPC18XX_GPIO_PIN_IC_SIENF);
 141        } else if (type & IRQ_TYPE_LEVEL_LOW) {
 142                lpc18xx_gpio_pin_ic_isel(ic, d->hwirq, true);
 143                lpc18xx_gpio_pin_ic_set(ic, d->hwirq,
 144                                        LPC18XX_GPIO_PIN_IC_CIENF);
 145        } else {
 146                lpc18xx_gpio_pin_ic_isel(ic, d->hwirq, false);
 147        }
 148
 149        raw_spin_unlock(&ic->lock);
 150
 151        return 0;
 152}
 153
 154static struct irq_chip lpc18xx_gpio_pin_ic = {
 155        .name           = "LPC18xx GPIO pin",
 156        .irq_mask       = lpc18xx_gpio_pin_ic_mask,
 157        .irq_unmask     = lpc18xx_gpio_pin_ic_unmask,
 158        .irq_eoi        = lpc18xx_gpio_pin_ic_eoi,
 159        .irq_set_type   = lpc18xx_gpio_pin_ic_set_type,
 160        .flags          = IRQCHIP_SET_TYPE_MASKED,
 161};
 162
 163static int lpc18xx_gpio_pin_ic_domain_alloc(struct irq_domain *domain,
 164                                            unsigned int virq,
 165                                            unsigned int nr_irqs, void *data)
 166{
 167        struct irq_fwspec parent_fwspec, *fwspec = data;
 168        struct lpc18xx_gpio_pin_ic *ic = domain->host_data;
 169        irq_hw_number_t hwirq;
 170        int ret;
 171
 172        if (nr_irqs != 1)
 173                return -EINVAL;
 174
 175        hwirq = fwspec->param[0];
 176        if (hwirq >= NR_LPC18XX_GPIO_PIN_IC_IRQS)
 177                return -EINVAL;
 178
 179        /*
 180         * All LPC18xx/LPC43xx GPIO pin hardware interrupts are translated
 181         * into edge interrupts 32...39 on parent Cortex-M3/M4 NVIC
 182         */
 183        parent_fwspec.fwnode = domain->parent->fwnode;
 184        parent_fwspec.param_count = 1;
 185        parent_fwspec.param[0] = hwirq + 32;
 186
 187        ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
 188        if (ret < 0) {
 189                pr_err("failed to allocate parent irq %u: %d\n",
 190                       parent_fwspec.param[0], ret);
 191                return ret;
 192        }
 193
 194        return irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
 195                                             &lpc18xx_gpio_pin_ic, ic);
 196}
 197
 198static const struct irq_domain_ops lpc18xx_gpio_pin_ic_domain_ops = {
 199        .alloc  = lpc18xx_gpio_pin_ic_domain_alloc,
 200        .xlate  = irq_domain_xlate_twocell,
 201        .free   = irq_domain_free_irqs_common,
 202};
 203
 204static int lpc18xx_gpio_pin_ic_probe(struct lpc18xx_gpio_chip *gc)
 205{
 206        struct device *dev = gc->gpio.parent;
 207        struct irq_domain *parent_domain;
 208        struct device_node *parent_node;
 209        struct lpc18xx_gpio_pin_ic *ic;
 210        struct resource res;
 211        int ret, index;
 212
 213        parent_node = of_irq_find_parent(dev->of_node);
 214        if (!parent_node)
 215                return -ENXIO;
 216
 217        parent_domain = irq_find_host(parent_node);
 218        of_node_put(parent_node);
 219        if (!parent_domain)
 220                return -ENXIO;
 221
 222        ic = devm_kzalloc(dev, sizeof(*ic), GFP_KERNEL);
 223        if (!ic)
 224                return -ENOMEM;
 225
 226        index = of_property_match_string(dev->of_node, "reg-names",
 227                                         "gpio-pin-ic");
 228        if (index < 0) {
 229                ret = -ENODEV;
 230                goto free_ic;
 231        }
 232
 233        ret = of_address_to_resource(dev->of_node, index, &res);
 234        if (ret < 0)
 235                goto free_ic;
 236
 237        ic->base = devm_ioremap_resource(dev, &res);
 238        if (IS_ERR(ic->base)) {
 239                ret = PTR_ERR(ic->base);
 240                goto free_ic;
 241        }
 242
 243        raw_spin_lock_init(&ic->lock);
 244
 245        ic->domain = irq_domain_add_hierarchy(parent_domain, 0,
 246                                              NR_LPC18XX_GPIO_PIN_IC_IRQS,
 247                                              dev->of_node,
 248                                              &lpc18xx_gpio_pin_ic_domain_ops,
 249                                              ic);
 250        if (!ic->domain) {
 251                pr_err("unable to add irq domain\n");
 252                ret = -ENODEV;
 253                goto free_iomap;
 254        }
 255
 256        gc->pin_ic = ic;
 257
 258        return 0;
 259
 260free_iomap:
 261        devm_iounmap(dev, ic->base);
 262free_ic:
 263        devm_kfree(dev, ic);
 264
 265        return ret;
 266}
 267
 268static void lpc18xx_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 269{
 270        struct lpc18xx_gpio_chip *gc = gpiochip_get_data(chip);
 271        writeb(value ? 1 : 0, gc->base + offset);
 272}
 273
 274static int lpc18xx_gpio_get(struct gpio_chip *chip, unsigned offset)
 275{
 276        struct lpc18xx_gpio_chip *gc = gpiochip_get_data(chip);
 277        return !!readb(gc->base + offset);
 278}
 279
 280static int lpc18xx_gpio_direction(struct gpio_chip *chip, unsigned offset,
 281                                  bool out)
 282{
 283        struct lpc18xx_gpio_chip *gc = gpiochip_get_data(chip);
 284        unsigned long flags;
 285        u32 port, pin, dir;
 286
 287        port = offset / LPC18XX_PINS_PER_PORT;
 288        pin  = offset % LPC18XX_PINS_PER_PORT;
 289
 290        spin_lock_irqsave(&gc->lock, flags);
 291        dir = readl(gc->base + LPC18XX_REG_DIR(port));
 292        if (out)
 293                dir |= BIT(pin);
 294        else
 295                dir &= ~BIT(pin);
 296        writel(dir, gc->base + LPC18XX_REG_DIR(port));
 297        spin_unlock_irqrestore(&gc->lock, flags);
 298
 299        return 0;
 300}
 301
 302static int lpc18xx_gpio_direction_input(struct gpio_chip *chip,
 303                                        unsigned offset)
 304{
 305        return lpc18xx_gpio_direction(chip, offset, false);
 306}
 307
 308static int lpc18xx_gpio_direction_output(struct gpio_chip *chip,
 309                                         unsigned offset, int value)
 310{
 311        lpc18xx_gpio_set(chip, offset, value);
 312        return lpc18xx_gpio_direction(chip, offset, true);
 313}
 314
 315static const struct gpio_chip lpc18xx_chip = {
 316        .label                  = "lpc18xx/43xx-gpio",
 317        .request                = gpiochip_generic_request,
 318        .free                   = gpiochip_generic_free,
 319        .direction_input        = lpc18xx_gpio_direction_input,
 320        .direction_output       = lpc18xx_gpio_direction_output,
 321        .set                    = lpc18xx_gpio_set,
 322        .get                    = lpc18xx_gpio_get,
 323        .ngpio                  = LPC18XX_MAX_PORTS * LPC18XX_PINS_PER_PORT,
 324        .owner                  = THIS_MODULE,
 325};
 326
 327static int lpc18xx_gpio_probe(struct platform_device *pdev)
 328{
 329        struct device *dev = &pdev->dev;
 330        struct lpc18xx_gpio_chip *gc;
 331        int index, ret;
 332
 333        gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
 334        if (!gc)
 335                return -ENOMEM;
 336
 337        gc->gpio = lpc18xx_chip;
 338        platform_set_drvdata(pdev, gc);
 339
 340        index = of_property_match_string(dev->of_node, "reg-names", "gpio");
 341        if (index < 0) {
 342                /* To support backward compatibility take the first resource */
 343                gc->base = devm_platform_ioremap_resource(pdev, 0);
 344        } else {
 345                struct resource res;
 346
 347                ret = of_address_to_resource(dev->of_node, index, &res);
 348                if (ret < 0)
 349                        return ret;
 350
 351                gc->base = devm_ioremap_resource(dev, &res);
 352        }
 353        if (IS_ERR(gc->base))
 354                return PTR_ERR(gc->base);
 355
 356        gc->clk = devm_clk_get(dev, NULL);
 357        if (IS_ERR(gc->clk)) {
 358                dev_err(dev, "input clock not found\n");
 359                return PTR_ERR(gc->clk);
 360        }
 361
 362        ret = clk_prepare_enable(gc->clk);
 363        if (ret) {
 364                dev_err(dev, "unable to enable clock\n");
 365                return ret;
 366        }
 367
 368        spin_lock_init(&gc->lock);
 369
 370        gc->gpio.parent = dev;
 371
 372        ret = devm_gpiochip_add_data(dev, &gc->gpio, gc);
 373        if (ret) {
 374                dev_err(dev, "failed to add gpio chip\n");
 375                clk_disable_unprepare(gc->clk);
 376                return ret;
 377        }
 378
 379        /* On error GPIO pin interrupt controller just won't be registered */
 380        lpc18xx_gpio_pin_ic_probe(gc);
 381
 382        return 0;
 383}
 384
 385static int lpc18xx_gpio_remove(struct platform_device *pdev)
 386{
 387        struct lpc18xx_gpio_chip *gc = platform_get_drvdata(pdev);
 388
 389        if (gc->pin_ic)
 390                irq_domain_remove(gc->pin_ic->domain);
 391
 392        clk_disable_unprepare(gc->clk);
 393
 394        return 0;
 395}
 396
 397static const struct of_device_id lpc18xx_gpio_match[] = {
 398        { .compatible = "nxp,lpc1850-gpio" },
 399        { }
 400};
 401MODULE_DEVICE_TABLE(of, lpc18xx_gpio_match);
 402
 403static struct platform_driver lpc18xx_gpio_driver = {
 404        .probe  = lpc18xx_gpio_probe,
 405        .remove = lpc18xx_gpio_remove,
 406        .driver = {
 407                .name           = "lpc18xx-gpio",
 408                .of_match_table = lpc18xx_gpio_match,
 409        },
 410};
 411module_platform_driver(lpc18xx_gpio_driver);
 412
 413MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
 414MODULE_AUTHOR("Vladimir Zapolskiy <vz@mleia.com>");
 415MODULE_DESCRIPTION("GPIO driver for LPC18xx/43xx");
 416MODULE_LICENSE("GPL v2");
 417