gpio: siox: Convert to immutable irq_chip

Convert the driver to immutable irq-chip with a bit of
intuition.

In this case I had to figure out a way to get to the
struct gpio_chip that would work even when the irq_chip
is not part of the driver state container. I did this by
just doing what most other GPIO drivers do and pass
the state struct as data to devm_gpiochip_add_data()
and rewrite accordingly.

Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/gpio-siox.c

@@ -10,7 +10,6 @@
 
 struct gpio_siox_ddata {
 	struct gpio_chip gchip;
-	struct irq_chip ichip;
 	struct mutex lock;
 	u8 setdata[1];
 	u8 getdata[3];
@@ -97,9 +96,8 @@ static int gpio_siox_get_data(struct siox_device *sdevice, const u8 buf[])
 
 static void gpio_siox_irq_ack(struct irq_data *d)
 {
-	struct irq_chip *ic = irq_data_get_irq_chip(d);
-	struct gpio_siox_ddata *ddata =
-		container_of(ic, struct gpio_siox_ddata, ichip);
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct gpio_siox_ddata *ddata = gpiochip_get_data(gc);
 
 	raw_spin_lock(&ddata->irqlock);
 	ddata->irq_status &= ~(1 << d->hwirq);
@@ -108,21 +106,21 @@ static void gpio_siox_irq_ack(struct irq_data *d)
 
 static void gpio_siox_irq_mask(struct irq_data *d)
 {
-	struct irq_chip *ic = irq_data_get_irq_chip(d);
-	struct gpio_siox_ddata *ddata =
-		container_of(ic, struct gpio_siox_ddata, ichip);
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct gpio_siox_ddata *ddata = gpiochip_get_data(gc);
 
 	raw_spin_lock(&ddata->irqlock);
 	ddata->irq_enable &= ~(1 << d->hwirq);
 	raw_spin_unlock(&ddata->irqlock);
+	gpiochip_disable_irq(gc, irqd_to_hwirq(d));
 }
 
 static void gpio_siox_irq_unmask(struct irq_data *d)
 {
-	struct irq_chip *ic = irq_data_get_irq_chip(d);
-	struct gpio_siox_ddata *ddata =
-		container_of(ic, struct gpio_siox_ddata, ichip);
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct gpio_siox_ddata *ddata = gpiochip_get_data(gc);
 
+	gpiochip_enable_irq(gc, irqd_to_hwirq(d));
 	raw_spin_lock(&ddata->irqlock);
 	ddata->irq_enable |= 1 << d->hwirq;
 	raw_spin_unlock(&ddata->irqlock);
@@ -130,9 +128,8 @@ static void gpio_siox_irq_unmask(struct irq_data *d)
 
 static int gpio_siox_irq_set_type(struct irq_data *d, u32 type)
 {
-	struct irq_chip *ic = irq_data_get_irq_chip(d);
-	struct gpio_siox_ddata *ddata =
-		container_of(ic, struct gpio_siox_ddata, ichip);
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct gpio_siox_ddata *ddata = gpiochip_get_data(gc);
 
 	raw_spin_lock(&ddata->irqlock);
 	ddata->irq_type[d->hwirq] = type;
@@ -143,8 +140,7 @@ static int gpio_siox_irq_set_type(struct irq_data *d, u32 type)
 
 static int gpio_siox_get(struct gpio_chip *chip, unsigned int offset)
 {
-	struct gpio_siox_ddata *ddata =
-		container_of(chip, struct gpio_siox_ddata, gchip);
+	struct gpio_siox_ddata *ddata = gpiochip_get_data(chip);
 	int ret;
 
 	mutex_lock(&ddata->lock);
@@ -167,8 +163,7 @@ static int gpio_siox_get(struct gpio_chip *chip, unsigned int offset)
 static void gpio_siox_set(struct gpio_chip *chip,
 			  unsigned int offset, int value)
 {
-	struct gpio_siox_ddata *ddata =
-		container_of(chip, struct gpio_siox_ddata, gchip);
+	struct gpio_siox_ddata *ddata = gpiochip_get_data(chip);
 	u8 mask = 1 << (19 - offset);
 
 	mutex_lock(&ddata->lock);
@@ -208,11 +203,22 @@ static int gpio_siox_get_direction(struct gpio_chip *chip, unsigned int offset)
 		return GPIO_LINE_DIRECTION_OUT;
 }
 
+static const struct irq_chip gpio_siox_irq_chip = {
+	.name = "siox-gpio",
+	.irq_ack = gpio_siox_irq_ack,
+	.irq_mask = gpio_siox_irq_mask,
+	.irq_unmask = gpio_siox_irq_unmask,
+	.irq_set_type = gpio_siox_irq_set_type,
+	.flags = IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
 static int gpio_siox_probe(struct siox_device *sdevice)
 {
 	struct gpio_siox_ddata *ddata;
 	struct gpio_irq_chip *girq;
 	struct device *dev = &sdevice->dev;
+	struct gpio_chip *gc;
 	int ret;
 
 	ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
@@ -224,30 +230,25 @@ static int gpio_siox_probe(struct siox_device *sdevice)
 	mutex_init(&ddata->lock);
 	raw_spin_lock_init(&ddata->irqlock);
 
-	ddata->gchip.base = -1;
-	ddata->gchip.can_sleep = 1;
-	ddata->gchip.parent = dev;
-	ddata->gchip.owner = THIS_MODULE;
-	ddata->gchip.get = gpio_siox_get;
-	ddata->gchip.set = gpio_siox_set;
-	ddata->gchip.direction_input = gpio_siox_direction_input;
-	ddata->gchip.direction_output = gpio_siox_direction_output;
-	ddata->gchip.get_direction = gpio_siox_get_direction;
-	ddata->gchip.ngpio = 20;
-
-	ddata->ichip.name = "siox-gpio";
-	ddata->ichip.irq_ack = gpio_siox_irq_ack;
-	ddata->ichip.irq_mask = gpio_siox_irq_mask;
-	ddata->ichip.irq_unmask = gpio_siox_irq_unmask;
-	ddata->ichip.irq_set_type = gpio_siox_irq_set_type;
-
-	girq = &ddata->gchip.irq;
-	girq->chip = &ddata->ichip;
+	gc = &ddata->gchip;
+	gc->base = -1;
+	gc->can_sleep = 1;
+	gc->parent = dev;
+	gc->owner = THIS_MODULE;
+	gc->get = gpio_siox_get;
+	gc->set = gpio_siox_set;
+	gc->direction_input = gpio_siox_direction_input;
+	gc->direction_output = gpio_siox_direction_output;
+	gc->get_direction = gpio_siox_get_direction;
+	gc->ngpio = 20;
+
+	girq = &gc->irq;
+	gpio_irq_chip_set_chip(girq, &gpio_siox_irq_chip);
 	girq->default_type = IRQ_TYPE_NONE;
 	girq->handler = handle_level_irq;
 	girq->threaded = true;
 
-	ret = devm_gpiochip_add_data(dev, &ddata->gchip, NULL);
+	ret = devm_gpiochip_add_data(dev, gc, ddata);
 	if (ret)
 		dev_err(dev, "Failed to register gpio chip (%d)\n", ret);