Commit 5561770f authored by Jérôme Pouiller's avatar Jérôme Pouiller Committed by Greg Kroah-Hartman
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staging: wfx: repair external IRQ for SDIO 



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: default avatarJérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200505123757.39506-6-Jerome.Pouiller@silabs.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ba52eddc

drivers/staging/wfx/bus_sdio.c

+25 −13
Original line number Diff line number Diff line
@@ -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;

	}



	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 {

	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;

}