1 #define _GNU_SOURCE 2 3 #include <stdint.h> 4 #include <stdio.h> 5 #include <stdlib.h> 6 #include <string.h> 7 #include <fcntl.h> 8 #include <unistd.h> 9 #include <argp.h> 10 #include <sys/stat.h> 11 #include <sys/mman.h> 12 #include <dirent.h> 13 #include "openbmc_intf.h" 14 #include "gpio.h" 15 #include "gpio_json.h" 16 17 #include <sys/ioctl.h> 18 #include <linux/gpio.h> 19 20 #define GPIO_PORT_OFFSET 8 21 #define GPIO_BASE_PATH "/sys/class/gpio" 22 23 cJSON* gpio_json = NULL; 24 25 int gpio_write(GPIO* gpio, uint8_t value) 26 { 27 g_assert (gpio != NULL); 28 struct gpiohandle_data data; 29 memset(&data, 0, sizeof(data)); 30 data.values[0] = value; 31 32 if (gpio->fd <= 0) 33 { 34 return GPIO_ERROR; 35 } 36 37 if (ioctl(gpio->fd, GPIOHANDLE_SET_LINE_VALUES_IOCTL, &data) < 0) 38 { 39 return GPIO_WRITE_ERROR; 40 } 41 42 return GPIO_OK; 43 } 44 45 int gpio_read(GPIO* gpio, uint8_t *value) 46 { 47 g_assert (gpio != NULL); 48 struct gpiohandle_data data; 49 memset(&data, 0, sizeof(data)); 50 51 if (gpio->fd <= 0) 52 { 53 return GPIO_ERROR; 54 } 55 56 if (ioctl(gpio->fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, &data) < 0) 57 { 58 return GPIO_READ_ERROR; 59 } 60 61 *value = data.values[0]; 62 63 return GPIO_OK; 64 } 65 66 /** 67 * Determine the GPIO base number for the system. It is found in 68 * the 'base' file in the /sys/class/gpio/gpiochipX/ directory where the 69 * /sys/class/gpio/gpiochipX/label file has a '1e780000.gpio' in it. 70 * 71 * Note: This method is ASPEED specific. Could add support for 72 * additional SOCs in the future. 73 * 74 * @return int - the GPIO base number, or < 0 if not found 75 */ 76 int get_gpio_base() 77 { 78 int gpio_base = -1; 79 80 DIR* dir = opendir(GPIO_BASE_PATH); 81 if (dir == NULL) 82 { 83 fprintf(stderr, "Unable to open directory %s\n", 84 GPIO_BASE_PATH); 85 return -1; 86 } 87 88 struct dirent* entry; 89 while ((entry = readdir(dir)) != NULL) 90 { 91 /* Look in the gpiochip<X> directories for a file called 'label' */ 92 /* that contains '1e780000.gpio', then in that directory read */ 93 /* the GPIO base out of the 'base' file. */ 94 95 if (strncmp(entry->d_name, "gpiochip", 8) != 0) 96 { 97 continue; 98 } 99 100 gboolean is_bmc = FALSE; 101 char* label_name; 102 asprintf(&label_name, "%s/%s/label", 103 GPIO_BASE_PATH, entry->d_name); 104 105 FILE* fd = fopen(label_name, "r"); 106 free(label_name); 107 108 if (!fd) 109 { 110 continue; 111 } 112 113 char label[14]; 114 if (fgets(label, 14, fd) != NULL) 115 { 116 if (strcmp(label, "1e780000.gpio") == 0) 117 { 118 is_bmc = TRUE; 119 } 120 } 121 fclose(fd); 122 123 if (!is_bmc) 124 { 125 continue; 126 } 127 128 char* base_name; 129 asprintf(&base_name, "%s/%s/base", 130 GPIO_BASE_PATH, entry->d_name); 131 132 fd = fopen(base_name, "r"); 133 free(base_name); 134 135 if (!fd) 136 { 137 continue; 138 } 139 140 if (fscanf(fd, "%d", &gpio_base) != 1) 141 { 142 gpio_base = -1; 143 } 144 fclose(fd); 145 146 /* We found the right file. No need to continue. */ 147 break; 148 } 149 closedir(dir); 150 151 if (gpio_base == -1) 152 { 153 fprintf(stderr, "Could not find GPIO base\n"); 154 } 155 156 return gpio_base; 157 } 158 159 /** 160 * Converts the GPIO port/offset nomenclature value 161 * to a number. Supports the ASPEED method where 162 * num = base + (port * 8) + offset, and the port is an 163 * A-Z character that converts to 0 to 25. The base 164 * is obtained form the hardware. 165 * 166 * For example: "A5" -> 5, "Z7" -> 207 167 * 168 * @param[in] gpio - the GPIO name 169 * 170 * @return int - the GPIO number or < 0 if not found 171 */ 172 int convert_gpio_to_num(const char* gpio) 173 { 174 size_t len = strlen(gpio); 175 if (len < 2) 176 { 177 fprintf(stderr, "Invalid GPIO name %s\n", gpio); 178 return -1; 179 } 180 181 /* Read the offset from the last character */ 182 if (!isdigit(gpio[len-1])) 183 { 184 fprintf(stderr, "Invalid GPIO offset in GPIO %s\n", gpio); 185 return -1; 186 } 187 188 int offset = gpio[len-1] - '0'; 189 190 /* Read the port from the second to last character */ 191 if (!isalpha(gpio[len-2])) 192 { 193 fprintf(stderr, "Invalid GPIO port in GPIO %s\n", gpio); 194 return -1; 195 } 196 int port = toupper(gpio[len-2]) - 'A'; 197 198 /* Check for a 2 character port, like AA */ 199 if ((len == 3) && isalpha(gpio[len-3])) 200 { 201 port += 26 * (toupper(gpio[len-3]) - 'A' + 1); 202 } 203 204 return (port * GPIO_PORT_OFFSET) + offset; 205 } 206 207 /** 208 * Returns the cJSON pointer to the GPIO definition 209 * for the GPIO passed in. 210 * 211 * @param[in] gpio_name - the GPIO name, like BMC_POWER_UP 212 * 213 * @return cJSON* - pointer to the cJSON object or NULL 214 * if not found. 215 */ 216 cJSON* get_gpio_def(const char* gpio_name) 217 { 218 if (gpio_json == NULL) 219 { 220 gpio_json = load_json(); 221 if (gpio_json == NULL) 222 { 223 return NULL; 224 } 225 } 226 227 cJSON* gpio_defs = cJSON_GetObjectItem(gpio_json, "gpio_definitions"); 228 g_assert(gpio_defs != NULL); 229 230 cJSON* def; 231 cJSON_ArrayForEach(def, gpio_defs) 232 { 233 cJSON* name = cJSON_GetObjectItem(def, "name"); 234 g_assert(name != NULL); 235 236 if (strcmp(name->valuestring, gpio_name) == 0) 237 { 238 return def; 239 } 240 } 241 return NULL; 242 } 243 244 /** 245 * Frees the gpio_json memory 246 * 247 * Can be called once when callers are done calling making calls 248 * to gpio_init() so that the JSON only needs to be loaded once. 249 */ 250 void gpio_inits_done() 251 { 252 if (gpio_json != NULL) 253 { 254 cJSON_Delete(gpio_json); 255 gpio_json = NULL; 256 } 257 } 258 259 /** 260 * Fills in the dev, direction, and num elements in 261 * the GPIO structure. 262 * 263 * @param gpio - the GPIO structure to fill in 264 * 265 * @return GPIO_OK if successful 266 */ 267 int gpio_get_params(GPIO* gpio) 268 { 269 gpio->dev = g_strdup(GPIO_BASE_PATH); 270 271 const cJSON* def = get_gpio_def(gpio->name); 272 if (def == NULL) 273 { 274 fprintf(stderr, "Unable to find GPIO %s in the JSON\n", 275 gpio->name); 276 return GPIO_LOOKUP_ERROR; 277 } 278 279 const cJSON* dir = cJSON_GetObjectItem(def, "direction"); 280 g_assert(dir != NULL); 281 gpio->direction = g_strdup(dir->valuestring); 282 283 /* Must use either 'num', like 87, or 'pin', like "A5" */ 284 const cJSON* num = cJSON_GetObjectItem(def, "num"); 285 if ((num != NULL) && cJSON_IsNumber(num)) 286 { 287 gpio->num = num->valueint; 288 } 289 else 290 { 291 const cJSON* pin = cJSON_GetObjectItem(def, "pin"); 292 g_assert(pin != NULL); 293 294 gpio->num = convert_gpio_to_num(pin->valuestring); 295 if (gpio->num < 0) 296 { 297 return GPIO_LOOKUP_ERROR; 298 } 299 } 300 // TODO: For the purposes of skeleton and the projects that use it, 301 // it should be safe to assume this will always be 0. Eventually skeleton 302 // should be going away, but if the need arises before then this may need 303 // to be updated to handle non-zero cases. 304 gpio->chip_id = 0; 305 return GPIO_OK; 306 } 307 308 int gpio_open(GPIO* gpio, uint8_t default_value) 309 { 310 g_assert (gpio != NULL); 311 312 char buf[255]; 313 sprintf(buf, "/dev/gpiochip%d", gpio->chip_id); 314 gpio->fd = open(buf, 0); 315 if (gpio->fd == -1) 316 { 317 return GPIO_OPEN_ERROR; 318 } 319 320 struct gpiohandle_request req; 321 memset(&req, 0, sizeof(req)); 322 strncpy(req.consumer_label, "skeleton-gpio", sizeof(req.consumer_label)); 323 324 // open gpio for writing or reading 325 if (gpio->direction == NULL) 326 { 327 gpio_close(gpio); 328 return GPIO_OPEN_ERROR; 329 } 330 req.flags = (strcmp(gpio->direction,"in") == 0) ? GPIOHANDLE_REQUEST_INPUT 331 : GPIOHANDLE_REQUEST_OUTPUT; 332 333 req.lineoffsets[0] = gpio->num; 334 req.lines = 1; 335 336 if (strcmp(gpio->direction,"out") == 0) 337 { 338 req.default_values[0] = default_value; 339 } 340 341 int rc = ioctl(gpio->fd, GPIO_GET_LINEHANDLE_IOCTL, &req); 342 if (rc < 0) 343 { 344 gpio_close(gpio); 345 return GPIO_OPEN_ERROR; 346 } 347 gpio_close(gpio); 348 gpio->fd = req.fd; 349 350 return GPIO_OK; 351 } 352 353 void gpio_close(GPIO* gpio) 354 { 355 if(gpio->fd < 0) 356 return; 357 358 close(gpio->fd); 359 gpio->fd = -1; 360 } 361