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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * regmap based generic GPIO driver4 *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 20struct 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 40static 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 48static 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 61static 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 else71 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 84static 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 else95 regmap_update_bits(gpio->regmap, reg, mask, 0);96}97 98static 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 else107 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 113static 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 else146 return GPIO_LINE_DIRECTION_IN;147}148 149static 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 else173 val = output ? mask : 0;174 175 return regmap_update_bits(gpio->regmap, reg, mask, val);176}177 178static 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 184static 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 192void *gpio_regmap_get_drvdata(struct gpio_regmap *gpio)193{194 return gpio->driver_data;195}196EXPORT_SYMBOL_GPL(gpio_regmap_get_drvdata);197 198/**199 * gpio_regmap_register() - Register a generic regmap GPIO controller200 * @config: configuration for gpio_regmap201 *202 * Return: A pointer to the registered gpio_regmap or ERR_PTR error value.203 */204struct 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->get = gpio_regmap_get;266 if (gpio->reg_set_base && gpio->reg_clr_base)267 chip->set = gpio_regmap_set_with_clear;268 else if (gpio->reg_set_base)269 chip->set = gpio_regmap_set;270 271 chip->get_direction = gpio_regmap_get_direction;272 if (gpio->reg_dir_in_base || gpio->reg_dir_out_base) {273 chip->direction_input = gpio_regmap_direction_input;274 chip->direction_output = gpio_regmap_direction_output;275 }276 277 ret = gpiochip_add_data(chip, gpio);278 if (ret < 0)279 goto err_free_gpio;280 281 if (config->irq_domain) {282 ret = gpiochip_irqchip_add_domain(chip, config->irq_domain);283 if (ret)284 goto err_remove_gpiochip;285 }286 287 return gpio;288 289err_remove_gpiochip:290 gpiochip_remove(chip);291err_free_gpio:292 kfree(gpio);293 return ERR_PTR(ret);294}295EXPORT_SYMBOL_GPL(gpio_regmap_register);296 297/**298 * gpio_regmap_unregister() - Unregister a generic regmap GPIO controller299 * @gpio: gpio_regmap device to unregister300 */301void gpio_regmap_unregister(struct gpio_regmap *gpio)302{303 gpiochip_remove(&gpio->gpio_chip);304 kfree(gpio);305}306EXPORT_SYMBOL_GPL(gpio_regmap_unregister);307 308static void devm_gpio_regmap_unregister(void *res)309{310 gpio_regmap_unregister(res);311}312 313/**314 * devm_gpio_regmap_register() - resource managed gpio_regmap_register()315 * @dev: device that is registering this GPIO device316 * @config: configuration for gpio_regmap317 *318 * Managed gpio_regmap_register(). For generic regmap GPIO device registered by319 * this function, gpio_regmap_unregister() is automatically called on driver320 * detach. See gpio_regmap_register() for more information.321 *322 * Return: A pointer to the registered gpio_regmap or ERR_PTR error value.323 */324struct gpio_regmap *devm_gpio_regmap_register(struct device *dev,325 const struct gpio_regmap_config *config)326{327 struct gpio_regmap *gpio;328 int ret;329 330 gpio = gpio_regmap_register(config);331 332 if (IS_ERR(gpio))333 return gpio;334 335 ret = devm_add_action_or_reset(dev, devm_gpio_regmap_unregister, gpio);336 if (ret)337 return ERR_PTR(ret);338 339 return gpio;340}341EXPORT_SYMBOL_GPL(devm_gpio_regmap_register);342 343MODULE_AUTHOR("Michael Walle <michael@walle.cc>");344MODULE_DESCRIPTION("GPIO generic regmap driver core");345MODULE_LICENSE("GPL");346