- 根目录:
- drivers
- mmc
- core
- sdio_irq.c
/*
* linux/drivers/mmc/core/sdio_irq.c
*
* Author: Nicolas Pitre
* Created: June 18, 2007
* Copyright: MontaVista Software Inc.
*
* Copyright 2008 Pierre Ossman
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/kthread.h>
#include <linux/export.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/mmc/core.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/sdio.h>
#include <linux/mmc/sdio_func.h>
#include "sdio_ops.h"
static int process_sdio_pending_irqs(struct mmc_host *host)
{
struct mmc_card *card = host->card;
int i, ret, count;
unsigned char pending;
struct sdio_func *func;
/*
* Optimization, if there is only 1 function interrupt registered
* and we know an IRQ was signaled then call irq handler directly.
* Otherwise do the full probe.
*/
func = card->sdio_single_irq;
if (func && host->sdio_irq_pending) {
func->irq_handler(func);
return 1;
}
ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
if (ret) {
pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
mmc_card_id(card), ret);
return ret;
}
if (pending && mmc_card_broken_irq_polling(card) &&
!(host->caps & MMC_CAP_SDIO_IRQ)) {
unsigned char dummy;
/* A fake interrupt could be created when we poll SDIO_CCCR_INTx
* register with a Marvell SD8797 card. A dummy CMD52 read to
* function 0 register 0xff can avoid this.
*/
mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy);
}
count = 0;
for (i = 1; i <= 7; i++) {
if (pending & (1 << i)) {
func = card->sdio_func[i - 1];
if (!func) {
pr_warn("%s: pending IRQ for non-existent function\n",
mmc_card_id(card));
ret = -EINVAL;
} else if (func->irq_handler) {
func->irq_handler(func);
count++;
} else {
pr_warn("%s: pending IRQ with no handler\n",
sdio_func_id(func));
ret = -EINVAL;
}
}
}
if (count)
return count;
return ret;
}
void sdio_run_irqs(struct mmc_host *host)
{
mmc_claim_host(host);
host->sdio_irq_pending = true;
process_sdio_pending_irqs(host);
mmc_release_host(host);
}
EXPORT_SYMBOL_GPL(sdio_run_irqs);
static int sdio_irq_thread(void *_host)
{
struct mmc_host *host = _host;
struct sched_param param = { .sched_priority = 1 };
unsigned long period, idle_period;
int ret;
sched_setscheduler(current, SCHED_FIFO, ¶m);
/*
* We want to allow for SDIO cards to work even on non SDIO
* aware hosts. One thing that non SDIO host cannot do is
* asynchronous notification of pending SDIO card interrupts
* hence we poll for them in that case.
*/
idle_period = msecs_to_jiffies(10);
period = (host->caps & MMC_CAP_SDIO_IRQ) ?
MAX_SCHEDULE_TIMEOUT : idle_period;
pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
mmc_hostname(host), period);
do {
/*
* We claim the host here on drivers behalf for a couple
* reasons:
*
* 1) it is already needed to retrieve the CCCR_INTx;
* 2) we want the driver(s) to clear the IRQ condition ASAP;
* 3) we need to control the abort condition locally.
*
* Just like traditional hard IRQ handlers, we expect SDIO
* IRQ handlers to be quick and to the point, so that the
* holding of the host lock does not cover too much work
* that doesn't require that lock to be held.
*/
ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort);
if (ret)
break;
ret = process_sdio_pending_irqs(host);
host->sdio_irq_pending = false;
mmc_release_host(host);
/*
* Give other threads a chance to run in the presence of
* errors.
*/
if (ret < 0) {
set_current_state(TASK_INTERRUPTIBLE);
if (!kthread_should_stop())
schedule_timeout(HZ);
set_current_state(TASK_RUNNING);
}
/*
* Adaptive polling frequency based on the assumption
* that an interrupt will be closely followed by more.
* This has a substantial benefit for network devices.
*/
if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
if (ret > 0)
period /= 2;
else {
period++;
if (period > idle_period)
period = idle_period;
}
}
set_current_state(TASK_INTERRUPTIBLE);
if (host->caps & MMC_CAP_SDIO_IRQ) {
mmc_host_clk_hold(host);
host->ops->enable_sdio_irq(host, 1);
mmc_host_clk_release(host);
}
if (!kthread_should_stop())
schedule_timeout(period);
set_current_state(TASK_RUNNING);
} while (!kthread_should_stop());
if (host->caps & MMC_CAP_SDIO_IRQ) {
mmc_host_clk_hold(host);
host->ops->enable_sdio_irq(host, 0);
mmc_host_clk_release(host);
}
pr_debug("%s: IRQ thread exiting with code %d\n",
mmc_hostname(host), ret);
return ret;
}
static int sdio_card_irq_get(struct mmc_card *card)
{
struct mmc_host *host = card->host;
WARN_ON(!host->claimed);
if (!host->sdio_irqs++) {
if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
atomic_set(&host->sdio_irq_thread_abort, 0);
host->sdio_irq_thread =
kthread_run(sdio_irq_thread, host,
"ksdioirqd/%s", mmc_hostname(host));
if (IS_ERR(host->sdio_irq_thread)) {
int err = PTR_ERR(host->sdio_irq_thread);
host->sdio_irqs--;
return err;
}
} else if (host->caps & MMC_CAP_SDIO_IRQ) {
mmc_host_clk_hold(host);
host->ops->enable_sdio_irq(host, 1);
mmc_host_clk_release(host);
}
}
return 0;
}
static int sdio_card_irq_put(struct mmc_card *card)
{
struct mmc_host *host = card->host;
WARN_ON(!host->claimed);
BUG_ON(host->sdio_irqs < 1);
if (!--host->sdio_irqs) {
if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
atomic_set(&host->sdio_irq_thread_abort, 1);
kthread_stop(host->sdio_irq_thread);
} else if (host->caps & MMC_CAP_SDIO_IRQ) {
mmc_host_clk_hold(host);
host->ops->enable_sdio_irq(host, 0);
mmc_host_clk_release(host);
}
}
return 0;
}
/* If there is only 1 function registered set sdio_single_irq */
static void sdio_single_irq_set(struct mmc_card *card)
{
struct sdio_func *func;
int i;
card->sdio_single_irq = NULL;
if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
card->host->sdio_irqs == 1)
for (i = 0; i < card->sdio_funcs; i++) {
func = card->sdio_func[i];
if (func && func->irq_handler) {
card->sdio_single_irq = func;
break;
}
}
}
/**
* sdio_claim_irq - claim the IRQ for a SDIO function
* @func: SDIO function
* @handler: IRQ handler callback
*
* Claim and activate the IRQ for the given SDIO function. The provided
* handler will be called when that IRQ is asserted. The host is always
* claimed already when the handler is called so the handler must not
* call sdio_claim_host() nor sdio_release_host().
*/
int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
{
int ret;
unsigned char reg;
BUG_ON(!func);
BUG_ON(!func->card);
pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));
if (func->irq_handler) {
pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
return -EBUSY;
}
ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
if (ret)
return ret;
reg |= 1 << func->num;
reg |= 1; /* Master interrupt enable */
ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
if (ret)
return ret;
func->irq_handler = handler;
ret = sdio_card_irq_get(func->card);
if (ret)
func->irq_handler = NULL;
sdio_single_irq_set(func->card);
return ret;
}
EXPORT_SYMBOL_GPL(sdio_claim_irq);
/**
* sdio_release_irq - release the IRQ for a SDIO function
* @func: SDIO function
*
* Disable and release the IRQ for the given SDIO function.
*/
int sdio_release_irq(struct sdio_func *func)
{
int ret;
unsigned char reg;
BUG_ON(!func);
BUG_ON(!func->card);
pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));
if (func->irq_handler) {
func->irq_handler = NULL;
sdio_card_irq_put(func->card);
sdio_single_irq_set(func->card);
}
ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
if (ret)
return ret;
reg &= ~(1 << func->num);
/* Disable master interrupt with the last function interrupt */
if (!(reg & 0xFE))
reg = 0;
ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
if (ret)
return ret;
return 0;
}
EXPORT_SYMBOL_GPL(sdio_release_irq);