LXR linux/drivers/gpio/gpio-regmap.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * regmap based generic GPIO driver
   4 *
   5 * Copyright 2020 Michael Walle <michael@walle.cc>
   6 */
   7
   8#include <linux/gpio/driver.h>
   9#include <linux/gpio/regmap.h>
  10#include <linux/kernel.h>
  11#include <linux/module.h>
  12#include <linux/regmap.h>
  13
  14struct gpio_regmap {
  15        struct device *parent;
  16        struct regmap *regmap;
  17        struct gpio_chip gpio_chip;
  18
  19        int reg_stride;
  20        int ngpio_per_reg;
  21        unsigned int reg_dat_base;
  22        unsigned int reg_set_base;
  23        unsigned int reg_clr_base;
  24        unsigned int reg_dir_in_base;
  25        unsigned int reg_dir_out_base;
  26
  27        int (*reg_mask_xlate)(struct gpio_regmap *gpio, unsigned int base,
  28                              unsigned int offset, unsigned int *reg,
  29                              unsigned int *mask);
  30
  31        void *driver_data;
  32};
  33
  34static unsigned int gpio_regmap_addr(unsigned int addr)
  35{
  36        if (addr == GPIO_REGMAP_ADDR_ZERO)
  37                return 0;
  38
  39        return addr;
  40}
  41
  42static int gpio_regmap_simple_xlate(struct gpio_regmap *gpio,
  43                                    unsigned int base, unsigned int offset,
  44                                    unsigned int *reg, unsigned int *mask)
  45{
  46        unsigned int line = offset % gpio->ngpio_per_reg;
  47        unsigned int stride = offset / gpio->ngpio_per_reg;
  48
  49        *reg = base + stride * gpio->reg_stride;
  50        *mask = BIT(line);
  51
  52        return 0;
  53}
  54
  55static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
  56{
  57        struct gpio_regmap *gpio = gpiochip_get_data(chip);
  58        unsigned int base, val, reg, mask;
  59        int ret;
  60
  61        /* we might not have an output register if we are input only */
  62        if (gpio->reg_dat_base)
  63                base = gpio_regmap_addr(gpio->reg_dat_base);
  64        else
  65                base = gpio_regmap_addr(gpio->reg_set_base);
  66
  67        ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
  68        if (ret)
  69                return ret;
  70
  71        ret = regmap_read(gpio->regmap, reg, &val);
  72        if (ret)
  73                return ret;
  74
  75        return !!(val & mask);
  76}
  77
  78static void gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
  79                            int val)
  80{
  81        struct gpio_regmap *gpio = gpiochip_get_data(chip);
  82        unsigned int base = gpio_regmap_addr(gpio->reg_set_base);
  83        unsigned int reg, mask;
  84
  85        gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
  86        if (val)
  87                regmap_update_bits(gpio->regmap, reg, mask, mask);
  88        else
  89                regmap_update_bits(gpio->regmap, reg, mask, 0);
  90}
  91
  92static void gpio_regmap_set_with_clear(struct gpio_chip *chip,
  93                                       unsigned int offset, int val)
  94{
  95        struct gpio_regmap *gpio = gpiochip_get_data(chip);
  96        unsigned int base, reg, mask;
  97
  98        if (val)
  99                base = gpio_regmap_addr(gpio->reg_set_base);
 100        else
 101                base = gpio_regmap_addr(gpio->reg_clr_base);
 102
 103        gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
 104        regmap_write(gpio->regmap, reg, mask);
 105}
 106
 107static int gpio_regmap_get_direction(struct gpio_chip *chip,
 108                                     unsigned int offset)
 109{
 110        struct gpio_regmap *gpio = gpiochip_get_data(chip);
 111        unsigned int base, val, reg, mask;
 112        int invert, ret;
 113
 114        if (gpio->reg_dir_out_base) {
 115                base = gpio_regmap_addr(gpio->reg_dir_out_base);
 116                invert = 0;
 117        } else if (gpio->reg_dir_in_base) {
 118                base = gpio_regmap_addr(gpio->reg_dir_in_base);
 119                invert = 1;
 120        } else {
 121                return -EOPNOTSUPP;
 122        }
 123
 124        ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
 125        if (ret)
 126                return ret;
 127
 128        ret = regmap_read(gpio->regmap, reg, &val);
 129        if (ret)
 130                return ret;
 131
 132        if (!!(val & mask) ^ invert)
 133                return GPIO_LINE_DIRECTION_OUT;
 134        else
 135                return GPIO_LINE_DIRECTION_IN;
 136}
 137
 138static int gpio_regmap_set_direction(struct gpio_chip *chip,
 139                                     unsigned int offset, bool output)
 140{
 141        struct gpio_regmap *gpio = gpiochip_get_data(chip);
 142        unsigned int base, val, reg, mask;
 143        int invert, ret;
 144
 145        if (gpio->reg_dir_out_base) {
 146                base = gpio_regmap_addr(gpio->reg_dir_out_base);
 147                invert = 0;
 148        } else if (gpio->reg_dir_in_base) {
 149                base = gpio_regmap_addr(gpio->reg_dir_in_base);
 150                invert = 1;
 151        } else {
 152                return -EOPNOTSUPP;
 153        }
 154
 155        ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
 156        if (ret)
 157                return ret;
 158
 159        if (invert)
 160                val = output ? 0 : mask;
 161        else
 162                val = output ? mask : 0;
 163
 164        return regmap_update_bits(gpio->regmap, reg, mask, val);
 165}
 166
 167static int gpio_regmap_direction_input(struct gpio_chip *chip,
 168                                       unsigned int offset)
 169{
 170        return gpio_regmap_set_direction(chip, offset, false);
 171}
 172
 173static int gpio_regmap_direction_output(struct gpio_chip *chip,
 174                                        unsigned int offset, int value)
 175{
 176        gpio_regmap_set(chip, offset, value);
 177
 178        return gpio_regmap_set_direction(chip, offset, true);
 179}
 180
 181void *gpio_regmap_get_drvdata(struct gpio_regmap *gpio)
 182{
 183        return gpio->driver_data;
 184}
 185EXPORT_SYMBOL_GPL(gpio_regmap_get_drvdata);
 186
 187/**
 188 * gpio_regmap_register() - Register a generic regmap GPIO controller
 189 * @config: configuration for gpio_regmap
 190 *
 191 * Return: A pointer to the registered gpio_regmap or ERR_PTR error value.
 192 */
 193struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config)
 194{
 195        struct gpio_regmap *gpio;
 196        struct gpio_chip *chip;
 197        int ret;
 198
 199        if (!config->parent)
 200                return ERR_PTR(-EINVAL);
 201
 202        if (!config->ngpio)
 203                return ERR_PTR(-EINVAL);
 204
 205        /* we need at least one */
 206        if (!config->reg_dat_base && !config->reg_set_base)
 207                return ERR_PTR(-EINVAL);
 208
 209        /* if we have a direction register we need both input and output */
 210        if ((config->reg_dir_out_base || config->reg_dir_in_base) &&
 211            (!config->reg_dat_base || !config->reg_set_base))
 212                return ERR_PTR(-EINVAL);
 213
 214        /* we don't support having both registers simultaneously for now */
 215        if (config->reg_dir_out_base && config->reg_dir_in_base)
 216                return ERR_PTR(-EINVAL);
 217
 218        gpio = kzalloc(sizeof(*gpio), GFP_KERNEL);
 219        if (!gpio)
 220                return ERR_PTR(-ENOMEM);
 221
 222        gpio->parent = config->parent;
 223        gpio->driver_data = config->drvdata;
 224        gpio->regmap = config->regmap;
 225        gpio->ngpio_per_reg = config->ngpio_per_reg;
 226        gpio->reg_stride = config->reg_stride;
 227        gpio->reg_mask_xlate = config->reg_mask_xlate;
 228        gpio->reg_dat_base = config->reg_dat_base;
 229        gpio->reg_set_base = config->reg_set_base;
 230        gpio->reg_clr_base = config->reg_clr_base;
 231        gpio->reg_dir_in_base = config->reg_dir_in_base;
 232        gpio->reg_dir_out_base = config->reg_dir_out_base;
 233
 234        /* if not set, assume there is only one register */
 235        if (!gpio->ngpio_per_reg)
 236                gpio->ngpio_per_reg = config->ngpio;
 237
 238        /* if not set, assume they are consecutive */
 239        if (!gpio->reg_stride)
 240                gpio->reg_stride = 1;
 241
 242        if (!gpio->reg_mask_xlate)
 243                gpio->reg_mask_xlate = gpio_regmap_simple_xlate;
 244
 245        chip = &gpio->gpio_chip;
 246        chip->parent = config->parent;
 247        chip->base = -1;
 248        chip->ngpio = config->ngpio;
 249        chip->names = config->names;
 250        chip->label = config->label ?: dev_name(config->parent);
 251
 252#if defined(CONFIG_OF_GPIO)
 253        /* gpiolib will use of_node of the parent if chip->of_node is NULL */
 254        chip->of_node = to_of_node(config->fwnode);
 255#endif /* CONFIG_OF_GPIO */
 256
 257        /*
 258         * If our regmap is fast_io we should probably set can_sleep to false.
 259         * Right now, the regmap doesn't save this property, nor is there any
 260         * access function for it.
 261         * The only regmap type which uses fast_io is regmap-mmio. For now,
 262         * assume a safe default of true here.
 263         */
 264        chip->can_sleep = true;
 265
 266        chip->get = gpio_regmap_get;
 267        if (gpio->reg_set_base && gpio->reg_clr_base)
 268                chip->set = gpio_regmap_set_with_clear;
 269        else if (gpio->reg_set_base)
 270                chip->set = gpio_regmap_set;
 271
 272        if (gpio->reg_dir_in_base || gpio->reg_dir_out_base) {
 273                chip->get_direction = gpio_regmap_get_direction;
 274                chip->direction_input = gpio_regmap_direction_input;
 275                chip->direction_output = gpio_regmap_direction_output;
 276        }
 277
 278        ret = gpiochip_add_data(chip, gpio);
 279        if (ret < 0)
 280                goto err_free_gpio;
 281
 282        if (config->irq_domain) {
 283                ret = gpiochip_irqchip_add_domain(chip, config->irq_domain);
 284                if (ret)
 285                        goto err_remove_gpiochip;
 286        }
 287
 288        return gpio;
 289
 290err_remove_gpiochip:
 291        gpiochip_remove(chip);
 292err_free_gpio:
 293        kfree(gpio);
 294        return ERR_PTR(ret);
 295}
 296EXPORT_SYMBOL_GPL(gpio_regmap_register);
 297
 298/**
 299 * gpio_regmap_unregister() - Unregister a generic regmap GPIO controller
 300 * @gpio: gpio_regmap device to unregister
 301 */
 302void gpio_regmap_unregister(struct gpio_regmap *gpio)
 303{
 304        gpiochip_remove(&gpio->gpio_chip);
 305        kfree(gpio);
 306}
 307EXPORT_SYMBOL_GPL(gpio_regmap_unregister);
 308
 309static void devm_gpio_regmap_unregister(void *res)
 310{
 311        gpio_regmap_unregister(res);
 312}
 313
 314/**
 315 * devm_gpio_regmap_register() - resource managed gpio_regmap_register()
 316 * @dev: device that is registering this GPIO device
 317 * @config: configuration for gpio_regmap
 318 *
 319 * Managed gpio_regmap_register(). For generic regmap GPIO device registered by
 320 * this function, gpio_regmap_unregister() is automatically called on driver
 321 * detach. See gpio_regmap_register() for more information.
 322 *
 323 * Return: A pointer to the registered gpio_regmap or ERR_PTR error value.
 324 */
 325struct gpio_regmap *devm_gpio_regmap_register(struct device *dev,
 326                                              const struct gpio_regmap_config *config)
 327{
 328        struct gpio_regmap *gpio;
 329        int ret;
 330
 331        gpio = gpio_regmap_register(config);
 332
 333        if (IS_ERR(gpio))
 334                return gpio;
 335
 336        ret = devm_add_action_or_reset(dev, devm_gpio_regmap_unregister, gpio);
 337        if (ret)
 338                return ERR_PTR(ret);
 339
 340        return gpio;
 341}
 342EXPORT_SYMBOL_GPL(devm_gpio_regmap_register);
 343
 344MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
 345MODULE_DESCRIPTION("GPIO generic regmap driver core");
 346MODULE_LICENSE("GPL");
 347