LCOV - code coverage report
Current view: top level - lkbce/drivers/mmc/core - sdio_irq.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 27 147 18.4 %
Date: 2017-01-25 Functions: 2 6 33.3 %

          Line data    Source code
       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 <linux/kthread.h>
      19             : #include <linux/wait.h>
      20             : #include <linux/delay.h>
      21             : 
      22             : #include <linux/mmc/core.h>
      23             : #include <linux/mmc/host.h>
      24             : #include <linux/mmc/card.h>
      25             : #include <linux/mmc/sdio.h>
      26             : #include <linux/mmc/sdio_func.h>
      27             : 
      28             : #include "sdio_ops.h"
      29             : 
      30             : static int process_sdio_pending_irqs(struct mmc_card *card)
      31             : {
      32           0 :         int i, ret, count;
      33           0 :         unsigned char pending;
      34           0 : 
      35           0 :         ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
      36           0 :         if (ret) {
      37           0 :                 printk(KERN_DEBUG "%s: error %d reading SDIO_CCCR_INTx\n",
      38           0 :                        mmc_card_id(card), ret);
      39           0 :                 return ret;
      40             :         }
      41             : 
      42           0 :         count = 0;
      43           0 :         for (i = 1; i <= 7; i++) {
      44           0 :                 if (pending & (1 << i)) {
      45           0 :                         struct sdio_func *func = card->sdio_func[i - 1];
      46           0 :                         if (!func) {
      47           0 :                                 printk(KERN_WARNING "%s: pending IRQ for "
      48             :                                         "non-existant function\n",
      49             :                                         mmc_card_id(card));
      50           0 :                                 ret = -EINVAL;
      51           0 :                         } else if (func->irq_handler) {
      52           0 :                                 func->irq_handler(func);
      53           0 :                                 count++;
      54             :                         } else {
      55           0 :                                 printk(KERN_WARNING "%s: pending IRQ with no handler\n",
      56             :                                        sdio_func_id(func));
      57           0 :                                 ret = -EINVAL;
      58             :                         }
      59             :                 }
      60             :         }
      61             : 
      62           0 :         if (count)
      63           0 :                 return count;
      64             : 
      65           0 :         return ret;
      66             : }
      67             : 
      68             : static int sdio_irq_thread(void *_host)
      69             : {
      70           0 :         struct mmc_host *host = _host;
      71           0 :         struct sched_param param = { .sched_priority = 1 };
      72           0 :         unsigned long period, idle_period;
      73           0 :         int ret;
      74           0 : 
      75           0 :         sched_setscheduler(current, SCHED_FIFO, &param);
      76           0 : 
      77           0 :         /*
      78           0 :          * We want to allow for SDIO cards to work even on non SDIO
      79           0 :          * aware hosts.  One thing that non SDIO host cannot do is
      80           0 :          * asynchronous notification of pending SDIO card interrupts
      81           0 :          * hence we poll for them in that case.
      82           0 :          */
      83           0 :         idle_period = msecs_to_jiffies(10);
      84           0 :         period = (host->caps & MMC_CAP_SDIO_IRQ) ?
      85           0 :                 MAX_SCHEDULE_TIMEOUT : idle_period;
      86           0 : 
      87           0 :         pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
      88           0 :                  mmc_hostname(host), period);
      89           0 : 
      90           0 :         do {
      91           0 :                 /*
      92           0 :                  * We claim the host here on drivers behalf for a couple
      93           0 :                  * reasons:
      94           0 :                  *
      95           0 :                  * 1) it is already needed to retrieve the CCCR_INTx;
      96           0 :                  * 2) we want the driver(s) to clear the IRQ condition ASAP;
      97           0 :                  * 3) we need to control the abort condition locally.
      98           0 :                  *
      99           0 :                  * Just like traditional hard IRQ handlers, we expect SDIO
     100           0 :                  * IRQ handlers to be quick and to the point, so that the
     101             :                  * holding of the host lock does not cover too much work
     102             :                  * that doesn't require that lock to be held.
     103             :                  */
     104           0 :                 ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort);
     105           0 :                 if (ret)
     106           0 :                         break;
     107           0 :                 ret = process_sdio_pending_irqs(host->card);
     108           0 :                 mmc_release_host(host);
     109             : 
     110             :                 /*
     111             :                  * Give other threads a chance to run in the presence of
     112             :                  * errors.
     113             :                  */
     114           0 :                 if (ret < 0) {
     115           0 :                         set_current_state(TASK_INTERRUPTIBLE);
     116           0 :                         if (!kthread_should_stop())
     117           0 :                                 schedule_timeout(HZ);
     118           0 :                         set_current_state(TASK_RUNNING);
     119           0 :                 }
     120             : 
     121             :                 /*
     122             :                  * Adaptive polling frequency based on the assumption
     123             :                  * that an interrupt will be closely followed by more.
     124             :                  * This has a substantial benefit for network devices.
     125             :                  */
     126           0 :                 if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
     127           0 :                         if (ret > 0)
     128           0 :                                 period /= 2;
     129             :                         else {
     130           0 :                                 period++;
     131           0 :                                 if (period > idle_period)
     132           0 :                                         period = idle_period;
     133             :                         }
     134             :                 }
     135             : 
     136           0 :                 set_current_state(TASK_INTERRUPTIBLE);
     137           0 :                 if (host->caps & MMC_CAP_SDIO_IRQ)
     138           0 :                         host->ops->enable_sdio_irq(host, 1);
     139           0 :                 if (!kthread_should_stop())
     140           0 :                         schedule_timeout(period);
     141           0 :                 set_current_state(TASK_RUNNING);
     142           0 :         } while (!kthread_should_stop());
     143             : 
     144           0 :         if (host->caps & MMC_CAP_SDIO_IRQ)
     145           0 :                 host->ops->enable_sdio_irq(host, 0);
     146             : 
     147           0 :         pr_debug("%s: IRQ thread exiting with code %d\n",
     148           0 :                  mmc_hostname(host), ret);
     149             : 
     150           0 :         return ret;
     151             : }
     152             : 
     153             : static int sdio_card_irq_get(struct mmc_card *card)
     154             : {
     155           0 :         struct mmc_host *host = card->host;
     156           0 : 
     157           0 :         WARN_ON(!host->claimed);
     158           0 : 
     159           0 :         if (!host->sdio_irqs++) {
     160           0 :                 atomic_set(&host->sdio_irq_thread_abort, 0);
     161           0 :                 host->sdio_irq_thread =
     162           0 :                         kthread_run(sdio_irq_thread, host, "ksdioirqd/%s",
     163           0 :                                 mmc_hostname(host));
     164           0 :                 if (IS_ERR(host->sdio_irq_thread)) {
     165           0 :                         int err = PTR_ERR(host->sdio_irq_thread);
     166           0 :                         host->sdio_irqs--;
     167           0 :                         return err;
     168             :                 }
     169             :         }
     170             : 
     171           0 :         return 0;
     172             : }
     173             : 
     174             : static int sdio_card_irq_put(struct mmc_card *card)
     175             : {
     176          24 :         struct mmc_host *host = card->host;
     177          12 : 
     178         108 :         WARN_ON(!host->claimed);
     179          84 :         BUG_ON(host->sdio_irqs < 1);
     180             : 
     181          36 :         if (!--host->sdio_irqs) {
     182          24 :                 atomic_set(&host->sdio_irq_thread_abort, 1);
     183          12 :                 kthread_stop(host->sdio_irq_thread);
     184             :         }
     185             : 
     186          24 :         return 0;
     187             : }
     188             : 
     189             : /**
     190             :  *      sdio_claim_irq - claim the IRQ for a SDIO function
     191             :  *      @func: SDIO function
     192             :  *      @handler: IRQ handler callback
     193             :  *
     194             :  *      Claim and activate the IRQ for the given SDIO function. The provided
     195             :  *      handler will be called when that IRQ is asserted.  The host is always
     196             :  *      claimed already when the handler is called so the handler must not
     197             :  *      call sdio_claim_host() nor sdio_release_host().
     198             :  */
     199             : int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
     200             : {
     201           0 :         int ret;
     202           0 :         unsigned char reg;
     203           0 : 
     204           0 :         BUG_ON(!func);
     205           0 :         BUG_ON(!func->card);
     206           0 : 
     207           0 :         pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));
     208             : 
     209           0 :         if (func->irq_handler) {
     210           0 :                 pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
     211           0 :                 return -EBUSY;
     212             :         }
     213             : 
     214           0 :         ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
     215           0 :         if (ret)
     216           0 :                 return ret;
     217             : 
     218           0 :         reg |= 1 << func->num;
     219             : 
     220           0 :         reg |= 1; /* Master interrupt enable */
     221             : 
     222           0 :         ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
     223           0 :         if (ret)
     224           0 :                 return ret;
     225             : 
     226           0 :         func->irq_handler = handler;
     227           0 :         ret = sdio_card_irq_get(func->card);
     228           0 :         if (ret)
     229           0 :                 func->irq_handler = NULL;
     230             : 
     231           0 :         return ret;
     232             : }
     233             : EXPORT_SYMBOL_GPL(sdio_claim_irq);
     234             : 
     235             : /**
     236             :  *      sdio_release_irq - release the IRQ for a SDIO function
     237             :  *      @func: SDIO function
     238             :  *
     239             :  *      Disable and release the IRQ for the given SDIO function.
     240             :  */
     241             : int sdio_release_irq(struct sdio_func *func)
     242             : {
     243          12 :         int ret;
     244          12 :         unsigned char reg;
     245          12 : 
     246          84 :         BUG_ON(!func);
     247          96 :         BUG_ON(!func->card);
     248             : 
     249          36 :         pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));
     250             : 
     251          36 :         if (func->irq_handler) {
     252          12 :                 func->irq_handler = NULL;
     253          36 :                 sdio_card_irq_put(func->card);
     254             :         }
     255             : 
     256          72 :         ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
     257          24 :         if (ret)
     258          12 :                 return ret;
     259             : 
     260          24 :         reg &= ~(1 << func->num);
     261             : 
     262             :         /* Disable master interrupt with the last function interrupt */
     263          24 :         if (!(reg & 0xFE))
     264          12 :                 reg = 0;
     265             : 
     266          36 :         ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
     267          24 :         if (ret)
     268          12 :                 return ret;
     269             : 
     270          12 :         return 0;
     271             : }
     272             : EXPORT_SYMBOL_GPL(sdio_release_irq);
     273             : 

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