![Pierre Ossman](/assets/img/avatar_default.png)
There is one thread per host controller so make sure they all get unique names. Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
274 lines
6.4 KiB
C
274 lines
6.4 KiB
C
/*
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* linux/drivers/mmc/core/sdio_irq.c
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*
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* Author: Nicolas Pitre
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* Created: June 18, 2007
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* Copyright: MontaVista Software Inc.
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*
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* Copyright 2008 Pierre Ossman
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or (at
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* your option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/kthread.h>
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#include <linux/wait.h>
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#include <linux/delay.h>
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#include <linux/mmc/core.h>
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#include <linux/mmc/host.h>
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#include <linux/mmc/card.h>
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#include <linux/mmc/sdio.h>
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#include <linux/mmc/sdio_func.h>
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#include "sdio_ops.h"
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static int process_sdio_pending_irqs(struct mmc_card *card)
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{
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int i, ret, count;
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unsigned char pending;
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ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
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if (ret) {
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printk(KERN_DEBUG "%s: error %d reading SDIO_CCCR_INTx\n",
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mmc_card_id(card), ret);
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return ret;
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}
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count = 0;
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for (i = 1; i <= 7; i++) {
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if (pending & (1 << i)) {
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struct sdio_func *func = card->sdio_func[i - 1];
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if (!func) {
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printk(KERN_WARNING "%s: pending IRQ for "
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"non-existant function\n",
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mmc_card_id(card));
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ret = -EINVAL;
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} else if (func->irq_handler) {
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func->irq_handler(func);
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count++;
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} else {
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printk(KERN_WARNING "%s: pending IRQ with no handler\n",
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sdio_func_id(func));
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ret = -EINVAL;
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}
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}
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}
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if (count)
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return count;
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return ret;
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}
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static int sdio_irq_thread(void *_host)
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{
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struct mmc_host *host = _host;
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struct sched_param param = { .sched_priority = 1 };
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unsigned long period, idle_period;
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int ret;
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sched_setscheduler(current, SCHED_FIFO, ¶m);
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/*
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* We want to allow for SDIO cards to work even on non SDIO
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* aware hosts. One thing that non SDIO host cannot do is
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* asynchronous notification of pending SDIO card interrupts
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* hence we poll for them in that case.
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*/
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idle_period = msecs_to_jiffies(10);
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period = (host->caps & MMC_CAP_SDIO_IRQ) ?
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MAX_SCHEDULE_TIMEOUT : idle_period;
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pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
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mmc_hostname(host), period);
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do {
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/*
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* We claim the host here on drivers behalf for a couple
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* reasons:
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*
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* 1) it is already needed to retrieve the CCCR_INTx;
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* 2) we want the driver(s) to clear the IRQ condition ASAP;
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* 3) we need to control the abort condition locally.
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*
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* Just like traditional hard IRQ handlers, we expect SDIO
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* IRQ handlers to be quick and to the point, so that the
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* holding of the host lock does not cover too much work
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* that doesn't require that lock to be held.
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*/
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ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort);
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if (ret)
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break;
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ret = process_sdio_pending_irqs(host->card);
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mmc_release_host(host);
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/*
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* Give other threads a chance to run in the presence of
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* errors.
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*/
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if (ret < 0) {
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set_current_state(TASK_INTERRUPTIBLE);
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if (!kthread_should_stop())
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schedule_timeout(HZ);
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set_current_state(TASK_RUNNING);
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}
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/*
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* Adaptive polling frequency based on the assumption
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* that an interrupt will be closely followed by more.
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* This has a substantial benefit for network devices.
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*/
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if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
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if (ret > 0)
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period /= 2;
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else {
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period++;
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if (period > idle_period)
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period = idle_period;
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}
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}
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set_current_state(TASK_INTERRUPTIBLE);
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if (host->caps & MMC_CAP_SDIO_IRQ)
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host->ops->enable_sdio_irq(host, 1);
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if (!kthread_should_stop())
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schedule_timeout(period);
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set_current_state(TASK_RUNNING);
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} while (!kthread_should_stop());
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if (host->caps & MMC_CAP_SDIO_IRQ)
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host->ops->enable_sdio_irq(host, 0);
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pr_debug("%s: IRQ thread exiting with code %d\n",
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mmc_hostname(host), ret);
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return ret;
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}
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static int sdio_card_irq_get(struct mmc_card *card)
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{
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struct mmc_host *host = card->host;
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WARN_ON(!host->claimed);
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if (!host->sdio_irqs++) {
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atomic_set(&host->sdio_irq_thread_abort, 0);
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host->sdio_irq_thread =
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kthread_run(sdio_irq_thread, host, "ksdioirqd/%s",
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mmc_hostname(host));
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if (IS_ERR(host->sdio_irq_thread)) {
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int err = PTR_ERR(host->sdio_irq_thread);
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host->sdio_irqs--;
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return err;
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}
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}
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return 0;
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}
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static int sdio_card_irq_put(struct mmc_card *card)
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{
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struct mmc_host *host = card->host;
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WARN_ON(!host->claimed);
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BUG_ON(host->sdio_irqs < 1);
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if (!--host->sdio_irqs) {
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atomic_set(&host->sdio_irq_thread_abort, 1);
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kthread_stop(host->sdio_irq_thread);
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}
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return 0;
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}
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/**
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* sdio_claim_irq - claim the IRQ for a SDIO function
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* @func: SDIO function
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* @handler: IRQ handler callback
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*
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* Claim and activate the IRQ for the given SDIO function. The provided
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* handler will be called when that IRQ is asserted. The host is always
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* claimed already when the handler is called so the handler must not
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* call sdio_claim_host() nor sdio_release_host().
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*/
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int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
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{
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int ret;
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unsigned char reg;
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BUG_ON(!func);
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BUG_ON(!func->card);
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pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));
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if (func->irq_handler) {
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pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
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return -EBUSY;
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}
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ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
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if (ret)
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return ret;
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reg |= 1 << func->num;
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reg |= 1; /* Master interrupt enable */
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ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
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if (ret)
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return ret;
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func->irq_handler = handler;
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ret = sdio_card_irq_get(func->card);
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if (ret)
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func->irq_handler = NULL;
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return ret;
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}
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EXPORT_SYMBOL_GPL(sdio_claim_irq);
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/**
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* sdio_release_irq - release the IRQ for a SDIO function
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* @func: SDIO function
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*
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* Disable and release the IRQ for the given SDIO function.
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*/
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int sdio_release_irq(struct sdio_func *func)
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{
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int ret;
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unsigned char reg;
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BUG_ON(!func);
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BUG_ON(!func->card);
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pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));
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if (func->irq_handler) {
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func->irq_handler = NULL;
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sdio_card_irq_put(func->card);
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}
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ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
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if (ret)
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return ret;
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reg &= ~(1 << func->num);
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/* Disable master interrupt with the last function interrupt */
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if (!(reg & 0xFE))
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reg = 0;
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ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
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if (ret)
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return ret;
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return 0;
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}
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EXPORT_SYMBOL_GPL(sdio_release_irq);
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