1 /* 2 * linux/drivers/mmc/core/sdio_irq.c 3 * 4 * Author: Nicolas Pitre 5 * Created: June 18, 2007 6 * Copyright: MontaVista Software Inc. 7 * 8 * Copyright 2008 Pierre Ossman 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation; either version 2 of the License, or (at 13 * your option) any later version. 14 */ 15 16 #include <linux/kernel.h> 17 #include <linux/sched.h> 18 #include <uapi/linux/sched/types.h> 19 #include <linux/kthread.h> 20 #include <linux/export.h> 21 #include <linux/wait.h> 22 #include <linux/delay.h> 23 24 #include <linux/mmc/core.h> 25 #include <linux/mmc/host.h> 26 #include <linux/mmc/card.h> 27 #include <linux/mmc/sdio.h> 28 #include <linux/mmc/sdio_func.h> 29 30 #include "sdio_ops.h" 31 #include "core.h" 32 #include "card.h" 33 34 static int process_sdio_pending_irqs(struct mmc_host *host) 35 { 36 struct mmc_card *card = host->card; 37 int i, ret, count; 38 unsigned char pending; 39 struct sdio_func *func; 40 41 /* 42 * Optimization, if there is only 1 function interrupt registered 43 * and we know an IRQ was signaled then call irq handler directly. 44 * Otherwise do the full probe. 45 */ 46 func = card->sdio_single_irq; 47 if (func && host->sdio_irq_pending) { 48 func->irq_handler(func); 49 return 1; 50 } 51 52 ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending); 53 if (ret) { 54 pr_debug("%s: error %d reading SDIO_CCCR_INTx\n", 55 mmc_card_id(card), ret); 56 return ret; 57 } 58 59 if (pending && mmc_card_broken_irq_polling(card) && 60 !(host->caps & MMC_CAP_SDIO_IRQ)) { 61 unsigned char dummy; 62 63 /* A fake interrupt could be created when we poll SDIO_CCCR_INTx 64 * register with a Marvell SD8797 card. A dummy CMD52 read to 65 * function 0 register 0xff can avoid this. 66 */ 67 mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy); 68 } 69 70 count = 0; 71 for (i = 1; i <= 7; i++) { 72 if (pending & (1 << i)) { 73 func = card->sdio_func[i - 1]; 74 if (!func) { 75 pr_warn("%s: pending IRQ for non-existent function\n", 76 mmc_card_id(card)); 77 ret = -EINVAL; 78 } else if (func->irq_handler) { 79 func->irq_handler(func); 80 count++; 81 } else { 82 pr_warn("%s: pending IRQ with no handler\n", 83 sdio_func_id(func)); 84 ret = -EINVAL; 85 } 86 } 87 } 88 89 if (count) 90 return count; 91 92 return ret; 93 } 94 95 void sdio_run_irqs(struct mmc_host *host) 96 { 97 mmc_claim_host(host); 98 if (host->sdio_irqs) { 99 host->sdio_irq_pending = true; 100 process_sdio_pending_irqs(host); 101 if (host->ops->ack_sdio_irq) 102 host->ops->ack_sdio_irq(host); 103 } 104 mmc_release_host(host); 105 } 106 EXPORT_SYMBOL_GPL(sdio_run_irqs); 107 108 void sdio_irq_work(struct work_struct *work) 109 { 110 struct mmc_host *host = 111 container_of(work, struct mmc_host, sdio_irq_work.work); 112 113 sdio_run_irqs(host); 114 } 115 116 void sdio_signal_irq(struct mmc_host *host) 117 { 118 queue_delayed_work(system_wq, &host->sdio_irq_work, 0); 119 } 120 EXPORT_SYMBOL_GPL(sdio_signal_irq); 121 122 static int sdio_irq_thread(void *_host) 123 { 124 struct mmc_host *host = _host; 125 struct sched_param param = { .sched_priority = 1 }; 126 unsigned long period, idle_period; 127 int ret; 128 129 sched_setscheduler(current, SCHED_FIFO, ¶m); 130 131 /* 132 * We want to allow for SDIO cards to work even on non SDIO 133 * aware hosts. One thing that non SDIO host cannot do is 134 * asynchronous notification of pending SDIO card interrupts 135 * hence we poll for them in that case. 136 */ 137 idle_period = msecs_to_jiffies(10); 138 period = (host->caps & MMC_CAP_SDIO_IRQ) ? 139 MAX_SCHEDULE_TIMEOUT : idle_period; 140 141 pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n", 142 mmc_hostname(host), period); 143 144 do { 145 /* 146 * We claim the host here on drivers behalf for a couple 147 * reasons: 148 * 149 * 1) it is already needed to retrieve the CCCR_INTx; 150 * 2) we want the driver(s) to clear the IRQ condition ASAP; 151 * 3) we need to control the abort condition locally. 152 * 153 * Just like traditional hard IRQ handlers, we expect SDIO 154 * IRQ handlers to be quick and to the point, so that the 155 * holding of the host lock does not cover too much work 156 * that doesn't require that lock to be held. 157 */ 158 ret = __mmc_claim_host(host, NULL, 159 &host->sdio_irq_thread_abort); 160 if (ret) 161 break; 162 ret = process_sdio_pending_irqs(host); 163 host->sdio_irq_pending = false; 164 mmc_release_host(host); 165 166 /* 167 * Give other threads a chance to run in the presence of 168 * errors. 169 */ 170 if (ret < 0) { 171 set_current_state(TASK_INTERRUPTIBLE); 172 if (!kthread_should_stop()) 173 schedule_timeout(HZ); 174 set_current_state(TASK_RUNNING); 175 } 176 177 /* 178 * Adaptive polling frequency based on the assumption 179 * that an interrupt will be closely followed by more. 180 * This has a substantial benefit for network devices. 181 */ 182 if (!(host->caps & MMC_CAP_SDIO_IRQ)) { 183 if (ret > 0) 184 period /= 2; 185 else { 186 period++; 187 if (period > idle_period) 188 period = idle_period; 189 } 190 } 191 192 set_current_state(TASK_INTERRUPTIBLE); 193 if (host->caps & MMC_CAP_SDIO_IRQ) 194 host->ops->enable_sdio_irq(host, 1); 195 if (!kthread_should_stop()) 196 schedule_timeout(period); 197 set_current_state(TASK_RUNNING); 198 } while (!kthread_should_stop()); 199 200 if (host->caps & MMC_CAP_SDIO_IRQ) 201 host->ops->enable_sdio_irq(host, 0); 202 203 pr_debug("%s: IRQ thread exiting with code %d\n", 204 mmc_hostname(host), ret); 205 206 return ret; 207 } 208 209 static int sdio_card_irq_get(struct mmc_card *card) 210 { 211 struct mmc_host *host = card->host; 212 213 WARN_ON(!host->claimed); 214 215 if (!host->sdio_irqs++) { 216 if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) { 217 atomic_set(&host->sdio_irq_thread_abort, 0); 218 host->sdio_irq_thread = 219 kthread_run(sdio_irq_thread, host, 220 "ksdioirqd/%s", mmc_hostname(host)); 221 if (IS_ERR(host->sdio_irq_thread)) { 222 int err = PTR_ERR(host->sdio_irq_thread); 223 host->sdio_irqs--; 224 return err; 225 } 226 } else if (host->caps & MMC_CAP_SDIO_IRQ) { 227 host->ops->enable_sdio_irq(host, 1); 228 } 229 } 230 231 return 0; 232 } 233 234 static int sdio_card_irq_put(struct mmc_card *card) 235 { 236 struct mmc_host *host = card->host; 237 238 WARN_ON(!host->claimed); 239 240 if (host->sdio_irqs < 1) 241 return -EINVAL; 242 243 if (!--host->sdio_irqs) { 244 if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) { 245 atomic_set(&host->sdio_irq_thread_abort, 1); 246 kthread_stop(host->sdio_irq_thread); 247 } else if (host->caps & MMC_CAP_SDIO_IRQ) { 248 host->ops->enable_sdio_irq(host, 0); 249 } 250 } 251 252 return 0; 253 } 254 255 /* If there is only 1 function registered set sdio_single_irq */ 256 static void sdio_single_irq_set(struct mmc_card *card) 257 { 258 struct sdio_func *func; 259 int i; 260 261 card->sdio_single_irq = NULL; 262 if ((card->host->caps & MMC_CAP_SDIO_IRQ) && 263 card->host->sdio_irqs == 1) 264 for (i = 0; i < card->sdio_funcs; i++) { 265 func = card->sdio_func[i]; 266 if (func && func->irq_handler) { 267 card->sdio_single_irq = func; 268 break; 269 } 270 } 271 } 272 273 /** 274 * sdio_claim_irq - claim the IRQ for a SDIO function 275 * @func: SDIO function 276 * @handler: IRQ handler callback 277 * 278 * Claim and activate the IRQ for the given SDIO function. The provided 279 * handler will be called when that IRQ is asserted. The host is always 280 * claimed already when the handler is called so the handler must not 281 * call sdio_claim_host() nor sdio_release_host(). 282 */ 283 int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler) 284 { 285 int ret; 286 unsigned char reg; 287 288 if (!func) 289 return -EINVAL; 290 291 pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func)); 292 293 if (func->irq_handler) { 294 pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func)); 295 return -EBUSY; 296 } 297 298 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); 299 if (ret) 300 return ret; 301 302 reg |= 1 << func->num; 303 304 reg |= 1; /* Master interrupt enable */ 305 306 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL); 307 if (ret) 308 return ret; 309 310 func->irq_handler = handler; 311 ret = sdio_card_irq_get(func->card); 312 if (ret) 313 func->irq_handler = NULL; 314 sdio_single_irq_set(func->card); 315 316 return ret; 317 } 318 EXPORT_SYMBOL_GPL(sdio_claim_irq); 319 320 /** 321 * sdio_release_irq - release the IRQ for a SDIO function 322 * @func: SDIO function 323 * 324 * Disable and release the IRQ for the given SDIO function. 325 */ 326 int sdio_release_irq(struct sdio_func *func) 327 { 328 int ret; 329 unsigned char reg; 330 331 if (!func) 332 return -EINVAL; 333 334 pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func)); 335 336 if (func->irq_handler) { 337 func->irq_handler = NULL; 338 sdio_card_irq_put(func->card); 339 sdio_single_irq_set(func->card); 340 } 341 342 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®); 343 if (ret) 344 return ret; 345 346 reg &= ~(1 << func->num); 347 348 /* Disable master interrupt with the last function interrupt */ 349 if (!(reg & 0xFE)) 350 reg = 0; 351 352 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL); 353 if (ret) 354 return ret; 355 356 return 0; 357 } 358 EXPORT_SYMBOL_GPL(sdio_release_irq); 359 360