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Commit 2997609e authored by Rafał Miłecki's avatar Rafał Miłecki Committed by Ralf Baechle
Browse files

bcma: gpio: add own IRQ domain 



Input GPIO changes can generate interrupts, but we need kind of ACK for
them by changing IRQ polarity. This is required to stop hardware from
keep generating interrupts and generate another one on the next GPIO
state change.
This code allows using GPIOs with standard interrupts and add for
example GPIO buttons support.

Signed-off-by: default avatarRafał Miłecki <zajec5@gmail.com>
Acked-by: default avatarHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: default avatarJohn Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6216/
parent 87c99203

drivers/bcma/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -75,6 +75,7 @@ config BCMA_DRIVER_GMAC_CMN 
config BCMA_DRIVER_GPIO

	bool "BCMA GPIO driver"

	depends on BCMA && GPIOLIB

	select IRQ_DOMAIN if BCMA_HOST_SOC

	help

	  Driver to provide access to the GPIO pins of the bcma bus.

drivers/bcma/driver_gpio.c

+132 −2
Original line number Diff line number Diff line
@@ -9,6 +9,9 @@ 
 */



#include <linux/gpio.h>

#include <linux/irq.h>

#include <linux/interrupt.h>

#include <linux/irqdomain.h>

#include <linux/export.h>

#include <linux/bcma/bcma.h>
@@ -73,19 +76,133 @@ static void bcma_gpio_free(struct gpio_chip *chip, unsigned gpio) 
	bcma_chipco_gpio_pullup(cc, 1 << gpio, 0);

}



#if IS_BUILTIN(CONFIG_BCMA_HOST_SOC)

static int bcma_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)

{

	struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);



	if (cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC)

		return bcma_core_irq(cc->core);

		return irq_find_mapping(cc->irq_domain, gpio);

	else

		return -EINVAL;

}



static void bcma_gpio_irq_unmask(struct irq_data *d)

{

	struct bcma_drv_cc *cc = irq_data_get_irq_chip_data(d);

	int gpio = irqd_to_hwirq(d);



	bcma_chipco_gpio_intmask(cc, BIT(gpio), BIT(gpio));

}



static void bcma_gpio_irq_mask(struct irq_data *d)

{

	struct bcma_drv_cc *cc = irq_data_get_irq_chip_data(d);

	int gpio = irqd_to_hwirq(d);



	bcma_chipco_gpio_intmask(cc, BIT(gpio), 0);

}



static struct irq_chip bcma_gpio_irq_chip = {

	.name		= "BCMA-GPIO",

	.irq_mask	= bcma_gpio_irq_mask,

	.irq_unmask	= bcma_gpio_irq_unmask,

};



static irqreturn_t bcma_gpio_irq_handler(int irq, void *dev_id)

{

	struct bcma_drv_cc *cc = dev_id;

	u32 val = bcma_cc_read32(cc, BCMA_CC_GPIOIN);

	u32 mask = bcma_cc_read32(cc, BCMA_CC_GPIOIRQ);

	u32 pol = bcma_cc_read32(cc, BCMA_CC_GPIOPOL);

	u32 irqs = (val ^ pol) & mask;

	int gpio;



	if (!irqs)

		return IRQ_NONE;



	for_each_set_bit(gpio, (unsigned long *)&irqs, cc->gpio.ngpio)

		generic_handle_irq(bcma_gpio_to_irq(&cc->gpio, gpio));

	bcma_chipco_gpio_polarity(cc, irqs, val & irqs);



	return IRQ_HANDLED;

}



static int bcma_gpio_irq_domain_init(struct bcma_drv_cc *cc)

{

	struct gpio_chip *chip = &cc->gpio;

	int gpio, hwirq, err;



	if (cc->core->bus->hosttype != BCMA_HOSTTYPE_SOC)

		return 0;



	cc->irq_domain = irq_domain_add_linear(NULL, chip->ngpio,

					       &irq_domain_simple_ops, cc);

	if (!cc->irq_domain) {

		err = -ENODEV;

		goto err_irq_domain;

	}

	for (gpio = 0; gpio < chip->ngpio; gpio++) {

		int irq = irq_create_mapping(cc->irq_domain, gpio);



		irq_set_chip_data(irq, cc);

		irq_set_chip_and_handler(irq, &bcma_gpio_irq_chip,

					 handle_simple_irq);

	}



	hwirq = bcma_core_irq(cc->core);

	err = request_irq(hwirq, bcma_gpio_irq_handler, IRQF_SHARED, "gpio",

			  cc);

	if (err)

		goto err_req_irq;



	bcma_cc_set32(cc, BCMA_CC_IRQMASK, BCMA_CC_IRQ_GPIO);



	return 0;



err_req_irq:

	for (gpio = 0; gpio < chip->ngpio; gpio++) {

		int irq = irq_find_mapping(cc->irq_domain, gpio);



		irq_dispose_mapping(irq);

	}

	irq_domain_remove(cc->irq_domain);

err_irq_domain:

	return err;

}



static void bcma_gpio_irq_domain_exit(struct bcma_drv_cc *cc)

{

	struct gpio_chip *chip = &cc->gpio;

	int gpio;



	if (cc->core->bus->hosttype != BCMA_HOSTTYPE_SOC)

		return;



	bcma_cc_mask32(cc, BCMA_CC_IRQMASK, ~BCMA_CC_IRQ_GPIO);

	free_irq(bcma_core_irq(cc->core), cc);

	for (gpio = 0; gpio < chip->ngpio; gpio++) {

		int irq = irq_find_mapping(cc->irq_domain, gpio);



		irq_dispose_mapping(irq);

	}

	irq_domain_remove(cc->irq_domain);

}

#else

static int bcma_gpio_irq_domain_init(struct bcma_drv_cc *cc)

{

	return 0;

}



static void bcma_gpio_irq_domain_exit(struct bcma_drv_cc *cc)

{

}

#endif



int bcma_gpio_init(struct bcma_drv_cc *cc)

{

	struct gpio_chip *chip = &cc->gpio;

	int err;



	chip->label		= "bcma_gpio";

	chip->owner		= THIS_MODULE;
@@ -95,7 +212,9 @@ int bcma_gpio_init(struct bcma_drv_cc *cc) 
	chip->set		= bcma_gpio_set_value;

	chip->direction_input	= bcma_gpio_direction_input;

	chip->direction_output	= bcma_gpio_direction_output;

#if IS_BUILTIN(CONFIG_BCMA_HOST_SOC)

	chip->to_irq		= bcma_gpio_to_irq;

#endif

	chip->ngpio		= 16;

	/* There is just one SoC in one device and its GPIO addresses should be

	 * deterministic to address them more easily. The other buses could get
@@ -105,10 +224,21 @@ int bcma_gpio_init(struct bcma_drv_cc *cc) 
	else

		chip->base		= -1;



	return gpiochip_add(chip);

	err = bcma_gpio_irq_domain_init(cc);

	if (err)

		return err;



	err = gpiochip_add(chip);

	if (err) {

		bcma_gpio_irq_domain_exit(cc);

		return err;

	}



	return 0;

}



int bcma_gpio_unregister(struct bcma_drv_cc *cc)

{

	bcma_gpio_irq_domain_exit(cc);

	return gpiochip_remove(&cc->gpio);

}

include/linux/bcma/bcma_driver_chipcommon.h

+1 −0
Original line number Diff line number Diff line
@@ -640,6 +640,7 @@ struct bcma_drv_cc { 
	spinlock_t gpio_lock;

#ifdef CONFIG_BCMA_DRIVER_GPIO

	struct gpio_chip gpio;

	struct irq_domain *irq_domain;

#endif

};