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gpio-regmap.c
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linux-6.19.14/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/bits.h> 9#include <linux/device.h> 10#include <linux/err.h> 11#include <linux/io.h> 12#include <linux/module.h> 13#include <linux/regmap.h> 14#include <linux/slab.h> 15#include <linux/types.h> 16 17#include <linux/gpio/driver.h> 18#include <linux/gpio/regmap.h> 19 20#include "gpiolib.h" 21 22struct gpio_regmap { 23 struct device *parent; 24 struct regmap *regmap; 25 struct gpio_chip gpio_chip; 26 27 int reg_stride; 28 int ngpio_per_reg; 29 unsigned int reg_dat_base; 30 unsigned int reg_set_base; 31 unsigned int reg_clr_base; 32 unsigned int reg_dir_in_base; 33 unsigned int reg_dir_out_base; 34 unsigned long *fixed_direction_output; 35 36#ifdef CONFIG_REGMAP_IRQ 37 int regmap_irq_line; 38 struct regmap_irq_chip_data *irq_chip_data; 39#endif 40 41 int (*reg_mask_xlate)(struct gpio_regmap *gpio, unsigned int base, 42 unsigned int offset, unsigned int *reg, 43 unsigned int *mask); 44 45 void *driver_data; 46}; 47 48static unsigned int gpio_regmap_addr(unsigned int addr) 49{ 50 if (addr == GPIO_REGMAP_ADDR_ZERO) 51 return 0; 52 53 return addr; 54} 55 56static int gpio_regmap_simple_xlate(struct gpio_regmap *gpio, 57 unsigned int base, unsigned int offset, 58 unsigned int *reg, unsigned int *mask) 59{ 60 unsigned int line = offset % gpio->ngpio_per_reg; 61 unsigned int stride = offset / gpio->ngpio_per_reg; 62 63 *reg = base + stride * gpio->reg_stride; 64 *mask = BIT(line); 65 66 return 0; 67} 68 69static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset) 70{ 71 struct gpio_regmap *gpio = gpiochip_get_data(chip); 72 unsigned int base, val, reg, mask; 73 int ret; 74 75 /* we might not have an output register if we are input only */ 76 if (gpio->reg_dat_base) 77 base = gpio_regmap_addr(gpio->reg_dat_base); 78 else 79 base = gpio_regmap_addr(gpio->reg_set_base); 80 81 ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask); 82 if (ret) 83 return ret; 84 85 /* ensure we don't spoil any register cache with pin input values */ 86 if (gpio->reg_dat_base == gpio->reg_set_base) 87 ret = regmap_read_bypassed(gpio->regmap, reg, &val); 88 else 89 ret = regmap_read(gpio->regmap, reg, &val); 90 if (ret) 91 return ret; 92 93 return !!(val & mask); 94} 95 96static int gpio_regmap_set(struct gpio_chip *chip, unsigned int offset, 97 int val) 98{ 99 struct gpio_regmap *gpio = gpiochip_get_data(chip); 100 unsigned int base = gpio_regmap_addr(gpio->reg_set_base); 101 unsigned int reg, mask, mask_val; 102 int ret; 103 104 ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask); 105 if (ret) 106 return ret; 107 108 if (val) 109 mask_val = mask; 110 else 111 mask_val = 0; 112 113 /* ignore input values which shadow the old output value */ 114 if (gpio->reg_dat_base == gpio->reg_set_base) 115 ret = regmap_write_bits(gpio->regmap, reg, mask, mask_val); 116 else 117 ret = regmap_update_bits(gpio->regmap, reg, mask, mask_val); 118 119 return ret; 120} 121 122static int gpio_regmap_set_with_clear(struct gpio_chip *chip, 123 unsigned int offset, int val) 124{ 125 struct gpio_regmap *gpio = gpiochip_get_data(chip); 126 unsigned int base, reg, mask; 127 int ret; 128 129 if (val) 130 base = gpio_regmap_addr(gpio->reg_set_base); 131 else 132 base = gpio_regmap_addr(gpio->reg_clr_base); 133 134 ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask); 135 if (ret) 136 return ret; 137 138 return regmap_write(gpio->regmap, reg, mask); 139} 140 141static int gpio_regmap_get_direction(struct gpio_chip *chip, 142 unsigned int offset) 143{ 144 struct gpio_regmap *gpio = gpiochip_get_data(chip); 145 unsigned int base, val, reg, mask; 146 int invert, ret; 147 148 if (gpio->fixed_direction_output) { 149 if (test_bit(offset, gpio->fixed_direction_output)) 150 return GPIO_LINE_DIRECTION_OUT; 151 else 152 return GPIO_LINE_DIRECTION_IN; 153 } 154 155 if (gpio->reg_dat_base && !gpio->reg_set_base) 156 return GPIO_LINE_DIRECTION_IN; 157 if (gpio->reg_set_base && !gpio->reg_dat_base) 158 return GPIO_LINE_DIRECTION_OUT; 159 160 if (gpio->reg_dir_out_base) { 161 base = gpio_regmap_addr(gpio->reg_dir_out_base); 162 invert = 0; 163 } else if (gpio->reg_dir_in_base) { 164 base = gpio_regmap_addr(gpio->reg_dir_in_base); 165 invert = 1; 166 } else { 167 return -ENOTSUPP; 168 } 169 170 ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask); 171 if (ret) 172 return ret; 173 174 ret = regmap_read(gpio->regmap, reg, &val); 175 if (ret) 176 return ret; 177 178 if (!!(val & mask) ^ invert) 179 return GPIO_LINE_DIRECTION_OUT; 180 else 181 return GPIO_LINE_DIRECTION_IN; 182} 183 184static int gpio_regmap_set_direction(struct gpio_chip *chip, 185 unsigned int offset, bool output) 186{ 187 struct gpio_regmap *gpio = gpiochip_get_data(chip); 188 unsigned int base, val, reg, mask; 189 int invert, ret; 190 191 if (gpio->reg_dir_out_base) { 192 base = gpio_regmap_addr(gpio->reg_dir_out_base); 193 invert = 0; 194 } else if (gpio->reg_dir_in_base) { 195 base = gpio_regmap_addr(gpio->reg_dir_in_base); 196 invert = 1; 197 } else { 198 return -ENOTSUPP; 199 } 200 201 ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask); 202 if (ret) 203 return ret; 204 205 if (invert) 206 val = output ? 0 : mask; 207 else 208 val = output ? mask : 0; 209 210 return regmap_update_bits(gpio->regmap, reg, mask, val); 211} 212 213static int gpio_regmap_direction_input(struct gpio_chip *chip, 214 unsigned int offset) 215{ 216 return gpio_regmap_set_direction(chip, offset, false); 217} 218 219static int gpio_regmap_direction_output(struct gpio_chip *chip, 220 unsigned int offset, int value) 221{ 222 gpio_regmap_set(chip, offset, value); 223 224 return gpio_regmap_set_direction(chip, offset, true); 225} 226 227void *gpio_regmap_get_drvdata(struct gpio_regmap *gpio) 228{ 229 return gpio->driver_data; 230} 231EXPORT_SYMBOL_GPL(gpio_regmap_get_drvdata); 232 233/** 234 * gpio_regmap_register() - Register a generic regmap GPIO controller 235 * @config: configuration for gpio_regmap 236 * 237 * Return: A pointer to the registered gpio_regmap or ERR_PTR error value. 238 */ 239struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config) 240{ 241 struct irq_domain *irq_domain; 242 struct gpio_regmap *gpio; 243 struct gpio_chip *chip; 244 int ret; 245 246 if (!config->parent) 247 return ERR_PTR(-EINVAL); 248 249 /* we need at least one */ 250 if (!config->reg_dat_base && !config->reg_set_base) 251 return ERR_PTR(-EINVAL); 252 253 /* if we have a direction register we need both input and output */ 254 if ((config->reg_dir_out_base || config->reg_dir_in_base) && 255 (!config->reg_dat_base || !config->reg_set_base)) 256 return ERR_PTR(-EINVAL); 257 258 /* we don't support having both registers simultaneously for now */ 259 if (config->reg_dir_out_base && config->reg_dir_in_base) 260 return ERR_PTR(-EINVAL); 261 262 gpio = kzalloc(sizeof(*gpio), GFP_KERNEL); 263 if (!gpio) 264 return ERR_PTR(-ENOMEM); 265 266 gpio->parent = config->parent; 267 gpio->driver_data = config->drvdata; 268 gpio->regmap = config->regmap; 269 gpio->reg_dat_base = config->reg_dat_base; 270 gpio->reg_set_base = config->reg_set_base; 271 gpio->reg_clr_base = config->reg_clr_base; 272 gpio->reg_dir_in_base = config->reg_dir_in_base; 273 gpio->reg_dir_out_base = config->reg_dir_out_base; 274 275 chip = &gpio->gpio_chip; 276 chip->parent = config->parent; 277 chip->fwnode = config->fwnode; 278 chip->base = -1; 279 chip->names = config->names; 280 chip->label = config->label ?: dev_name(config->parent); 281 chip->can_sleep = regmap_might_sleep(config->regmap); 282 chip->init_valid_mask = config->init_valid_mask; 283 284 chip->request = gpiochip_generic_request; 285 chip->free = gpiochip_generic_free; 286 chip->get = gpio_regmap_get; 287 if (gpio->reg_set_base && gpio->reg_clr_base) 288 chip->set = gpio_regmap_set_with_clear; 289 else if (gpio->reg_set_base) 290 chip->set = gpio_regmap_set; 291 292 chip->get_direction = gpio_regmap_get_direction; 293 if (gpio->reg_dir_in_base || gpio->reg_dir_out_base) { 294 chip->direction_input = gpio_regmap_direction_input; 295 chip->direction_output = gpio_regmap_direction_output; 296 } 297 298 chip->ngpio = config->ngpio; 299 if (!chip->ngpio) { 300 ret = gpiochip_get_ngpios(chip, chip->parent); 301 if (ret) 302 goto err_free_gpio; 303 } 304 305 if (config->fixed_direction_output) { 306 gpio->fixed_direction_output = bitmap_alloc(chip->ngpio, 307 GFP_KERNEL); 308 if (!gpio->fixed_direction_output) { 309 ret = -ENOMEM; 310 goto err_free_gpio; 311 } 312 bitmap_copy(gpio->fixed_direction_output, 313 config->fixed_direction_output, chip->ngpio); 314 } 315 316 /* if not set, assume there is only one register */ 317 gpio->ngpio_per_reg = config->ngpio_per_reg; 318 if (!gpio->ngpio_per_reg) 319 gpio->ngpio_per_reg = config->ngpio; 320 321 /* if not set, assume they are consecutive */ 322 gpio->reg_stride = config->reg_stride; 323 if (!gpio->reg_stride) 324 gpio->reg_stride = 1; 325 326 gpio->reg_mask_xlate = config->reg_mask_xlate; 327 if (!gpio->reg_mask_xlate) 328 gpio->reg_mask_xlate = gpio_regmap_simple_xlate; 329 330 ret = gpiochip_add_data(chip, gpio); 331 if (ret < 0) 332 goto err_free_bitmap; 333 334#ifdef CONFIG_REGMAP_IRQ 335 if (config->regmap_irq_chip) { 336 gpio->regmap_irq_line = config->regmap_irq_line; 337 ret = regmap_add_irq_chip_fwnode(dev_fwnode(config->parent), config->regmap, 338 config->regmap_irq_line, config->regmap_irq_flags, 339 0, config->regmap_irq_chip, &gpio->irq_chip_data); 340 if (ret) 341 goto err_remove_gpiochip; 342 343 irq_domain = regmap_irq_get_domain(gpio->irq_chip_data); 344 } else 345#endif 346 irq_domain = config->irq_domain; 347 348 if (irq_domain) { 349 ret = gpiochip_irqchip_add_domain(chip, irq_domain); 350 if (ret) 351 goto err_remove_gpiochip; 352 } 353 354 return gpio; 355 356err_remove_gpiochip: 357 gpiochip_remove(chip); 358err_free_bitmap: 359 bitmap_free(gpio->fixed_direction_output); 360err_free_gpio: 361 kfree(gpio); 362 return ERR_PTR(ret); 363} 364EXPORT_SYMBOL_GPL(gpio_regmap_register); 365 366/** 367 * gpio_regmap_unregister() - Unregister a generic regmap GPIO controller 368 * @gpio: gpio_regmap device to unregister 369 */ 370void gpio_regmap_unregister(struct gpio_regmap *gpio) 371{ 372#ifdef CONFIG_REGMAP_IRQ 373 if (gpio->irq_chip_data) 374 regmap_del_irq_chip(gpio->regmap_irq_line, gpio->irq_chip_data); 375#endif 376 377 gpiochip_remove(&gpio->gpio_chip); 378 bitmap_free(gpio->fixed_direction_output); 379 kfree(gpio); 380} 381EXPORT_SYMBOL_GPL(gpio_regmap_unregister); 382 383static void devm_gpio_regmap_unregister(void *res) 384{ 385 gpio_regmap_unregister(res); 386} 387 388/** 389 * devm_gpio_regmap_register() - resource managed gpio_regmap_register() 390 * @dev: device that is registering this GPIO device 391 * @config: configuration for gpio_regmap 392 * 393 * Managed gpio_regmap_register(). For generic regmap GPIO device registered by 394 * this function, gpio_regmap_unregister() is automatically called on driver 395 * detach. See gpio_regmap_register() for more information. 396 * 397 * Return: A pointer to the registered gpio_regmap or ERR_PTR error value. 398 */ 399struct gpio_regmap *devm_gpio_regmap_register(struct device *dev, 400 const struct gpio_regmap_config *config) 401{ 402 struct gpio_regmap *gpio; 403 int ret; 404 405 gpio = gpio_regmap_register(config); 406 407 if (IS_ERR(gpio)) 408 return gpio; 409 410 ret = devm_add_action_or_reset(dev, devm_gpio_regmap_unregister, gpio); 411 if (ret) 412 return ERR_PTR(ret); 413 414 return gpio; 415} 416EXPORT_SYMBOL_GPL(devm_gpio_regmap_register); 417 418MODULE_AUTHOR("Michael Walle <michael@walle.cc>"); 419MODULE_DESCRIPTION("GPIO generic regmap driver core"); 420MODULE_LICENSE("GPL");
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