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staging: wfx: repair external IRQ for SDIO

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When used over SDIO bus, device is able to use an external line to
signal IRQs (also called Out-Of-Band IRQ). The current code have several
problems:
  1. The ISR cannot directly acknowledge IRQ since access to the bus is
     not atomic. This patch use a threaded IRQ to solve that issue.
  2. On certain platforms, it is necessary to keep SDIO interruption
     enabled (with register SDIO_CCCR_IENx) (this part has inspired from
     the brcmfmac driver).

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200505123757.39506-6-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jérôme Pouiller 2020-05-05 14:37:47 +02:00 committed by Greg Kroah-Hartman
parent ba52eddcbb
commit 5561770f80
1 changed files with 25 additions and 13 deletions
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38
drivers/staging/wfx/bus_sdio.c
View File

@ -6,10 +6,12 @@
* Copyright (c) 2010, ST-Ericsson
*/
#include <linux/module.h>
#include <linux/mmc/sdio.h>
#include <linux/mmc/sdio_func.h>
#include <linux/mmc/card.h>
#include <linux/interrupt.h>
#include <linux/of_irq.h>
#include <linux/irq.h>
#include "bus.h"
#include "wfx.h"
@ -106,31 +108,41 @@ static irqreturn_t wfx_sdio_irq_handler_ext(int irq, void *priv)
static int wfx_sdio_irq_subscribe(struct wfx_sdio_priv *bus)
{
u32 flags;
int ret;
u8 cccr;
if (bus->of_irq) {
ret = request_irq(bus->of_irq, wfx_sdio_irq_handler_ext,
IRQF_TRIGGER_RISING, "wfx", bus);
} else {
if (!bus->of_irq) {
sdio_claim_host(bus->func);
ret = sdio_claim_irq(bus->func, wfx_sdio_irq_handler);
sdio_release_host(bus->func);
return ret;
}
return ret;
sdio_claim_host(bus->func);
cccr = sdio_f0_readb(bus->func, SDIO_CCCR_IENx, NULL);
cccr |= BIT(0);
cccr |= BIT(bus->func->num);
sdio_f0_writeb(bus->func, cccr, SDIO_CCCR_IENx, NULL);
sdio_release_host(bus->func);
flags = irq_get_trigger_type(bus->of_irq);
if (!flags)
flags = IRQF_TRIGGER_HIGH;
flags |= IRQF_ONESHOT;
return devm_request_threaded_irq(&bus->func->dev, bus->of_irq, NULL,
wfx_sdio_irq_handler_ext, flags,
"wfx", bus);
}
static int wfx_sdio_irq_unsubscribe(struct wfx_sdio_priv *bus)
{
int ret;
if (bus->of_irq) {
free_irq(bus->of_irq, bus);
ret = 0;
} else {
sdio_claim_host(bus->func);
ret = sdio_release_irq(bus->func);
sdio_release_host(bus->func);
}
if (bus->of_irq)
devm_free_irq(&bus->func->dev, bus->of_irq, bus);
sdio_claim_host(bus->func);
ret = sdio_release_irq(bus->func);
sdio_release_host(bus->func);
return ret;
}