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yaml
---
r: 65617
b: refs/heads/master
c: d1496c3
h: refs/heads/master
i:
  65615: 1ce684a
v: v3
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Nicolas Pitre authored and Pierre Ossman committed Sep 23, 2007
1 parent ff7dc97 commit 4cfbddc
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Showing 6 changed files with 258 additions and 2 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 2342f3323c9a76367a1d7f9a35525ee3cb3911df
refs/heads/master: d1496c39e500857b8949cdb91af24e0eb8aae4d0
2 changes: 1 addition & 1 deletion trunk/drivers/mmc/core/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -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

8 changes: 8 additions & 0 deletions trunk/drivers/mmc/core/sdio_bus.c
Original file line number Diff line number Diff line change
Expand Up @@ -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;
}

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237 changes: 237 additions & 0 deletions trunk/drivers/mmc/core/sdio_irq.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,237 @@
/*
* 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);

4 changes: 4 additions & 0 deletions trunk/include/linux/mmc/host.h
Original file line number Diff line number Diff line change
Expand Up @@ -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;
};

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7 changes: 7 additions & 0 deletions trunk/include/linux/mmc/sdio_func.h
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand All @@ -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 */
Expand Down Expand Up @@ -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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