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