drivers/gpio/gpio-lpc18xx.c

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