Commit d1496c39 authored by Nicolas Pitre's avatar Nicolas Pitre Committed by Pierre Ossman

sdio: core support for SDIO function interrupt

Signed-off-by: default avatarNicolas Pitre <npitre@mvista.com>
Signed-off-by: default avatarPierre Ossman <drzeus@drzeus.cx>
parent 2342f332
......@@ -10,5 +10,5 @@ obj-$(CONFIG_MMC) += mmc_core.o
mmc_core-y := core.o sysfs.o bus.o host.o \
mmc.o mmc_ops.o sd.o sd_ops.o \
sdio.o sdio_ops.o sdio_bus.o \
sdio_cis.o sdio_io.o
sdio_cis.o sdio_io.o sdio_irq.o
......@@ -143,6 +143,14 @@ static int sdio_bus_remove(struct device *dev)
drv->remove(func);
if (func->irq_handler) {
printk(KERN_WARNING "WARNING: driver %s did not remove "
"its interrupt handler!\n", drv->name);
sdio_claim_host(func);
sdio_release_irq(func);
sdio_release_host(func);
}
return 0;
}
......
/*
* linux/drivers/mmc/core/sdio_irq.c
*
* Author: Nicolas Pitre
* Created: June 18, 2007
* Copyright: MontaVista Software Inc.
*
* 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/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_card *card)
{
int i, ret;
unsigned char pending;
ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
if (ret) {
printk(KERN_DEBUG "%s: error %d reading SDIO_CCCR_INTx\n",
mmc_card_id(card), ret);
return ret;
}
for (i = 1; i <= 7; i++) {
if (pending & (1 << i)) {
struct sdio_func *func = card->sdio_func[i - 1];
if (!func) {
printk(KERN_WARNING "%s: pending IRQ for "
"non-existant function\n",
sdio_func_id(func));
} else if (func->irq_handler) {
func->irq_handler(func);
} else
printk(KERN_WARNING "%s: pending IRQ with no handler\n",
sdio_func_id(func));
}
}
return 0;
}
static int sdio_irq_thread(void *_host)
{
struct mmc_host *host = _host;
struct sched_param param = { .sched_priority = 1 };
unsigned long period;
int ret;
sched_setscheduler(current, SCHED_FIFO, &param);
/*
* 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.
*/
period = msecs_to_jiffies(10);
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->card);
mmc_release_host(host);
/*
* Give other threads a chance to run in the presence of
* errors. FIXME: determine if due to card removal and
* possibly exit this thread if so.
*/
if (ret)
ssleep(1);
set_task_state(current, TASK_INTERRUPTIBLE);
if (!kthread_should_stop())
schedule_timeout(period);
set_task_state(current, TASK_RUNNING);
} while (!kthread_should_stop());
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;
BUG_ON(!host->claimed);
if (!host->sdio_irqs++) {
atomic_set(&host->sdio_irq_thread_abort, 0);
host->sdio_irq_thread =
kthread_run(sdio_irq_thread, host, "ksdiorqd");
if (IS_ERR(host->sdio_irq_thread)) {
int err = PTR_ERR(host->sdio_irq_thread);
host->sdio_irqs--;
return err;
}
}
return 0;
}
static int sdio_card_irq_put(struct mmc_card *card)
{
struct mmc_host *host = card->host;
BUG_ON(!host->claimed);
BUG_ON(host->sdio_irqs < 1);
if (!--host->sdio_irqs) {
atomic_set(&host->sdio_irq_thread_abort, 1);
kthread_stop(host->sdio_irq_thread);
}
return 0;
}
/**
* 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, &reg);
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;
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);
}
ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
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);
......@@ -123,6 +123,10 @@ struct mmc_host {
unsigned int bus_refs; /* reference counter */
unsigned int bus_dead:1; /* bus has been released */
unsigned int sdio_irqs;
struct task_struct *sdio_irq_thread;
atomic_t sdio_irq_thread_abort;
unsigned long private[0] ____cacheline_aligned;
};
......
......@@ -16,6 +16,9 @@
#include <linux/mod_devicetable.h>
struct mmc_card;
struct sdio_func;
typedef void (sdio_irq_handler_t)(struct sdio_func *);
/*
* SDIO function CIS tuple (unknown to the core)
......@@ -33,6 +36,7 @@ struct sdio_func_tuple {
struct sdio_func {
struct mmc_card *card; /* the card this device belongs to */
struct device dev; /* the device */
sdio_irq_handler_t *irq_handler; /* IRQ callback */
unsigned int num; /* function number */
unsigned char class; /* standard interface class */
......@@ -105,6 +109,9 @@ extern void sdio_release_host(struct sdio_func *func);
extern int sdio_enable_func(struct sdio_func *func);
extern int sdio_disable_func(struct sdio_func *func);
extern int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler);
extern int sdio_release_irq(struct sdio_func *func);
extern unsigned char sdio_readb(struct sdio_func *func,
unsigned int addr, int *err_ret);
......
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