gpio/mvebu: Use irq_domain_add_linear

commit 812d4788 upstream.

This fixes the irq allocation in this driver to not print:
 irq: Cannot allocate irq_descs @ IRQ34, assuming pre-allocated
 irq: Cannot allocate irq_descs @ IRQ66, assuming pre-allocated

Which happens because the driver already called irq_alloc_descs()
and so the change to use irq_domain_add_simple resulted in calling
irq_alloc_descs() twice.

Modernize the irq allocation in this driver to use the
irq_domain_add_linear flow directly and eliminate the use of
irq_domain_add_simple/legacy

Fixes: ce931f57 ("gpio/mvebu: convert to use irq_domain_add_simple()")
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[bwh: Backported to 3.16:
 - Keep using irq_set_handler_data(), irq_set_chained_handler()
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/gpio/gpio-mvebu.c

@@ -294,10 +294,10 @@ static void mvebu_gpio_irq_ack(struct irq_data *d)
 {
 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 	struct mvebu_gpio_chip *mvchip = gc->private;
-	u32 mask = ~(1 << (d->irq - gc->irq_base));
+	u32 mask = d->mask;
 
 	irq_gc_lock(gc);
-	writel_relaxed(mask, mvebu_gpioreg_edge_cause(mvchip));
+	writel_relaxed(~mask, mvebu_gpioreg_edge_cause(mvchip));
 	irq_gc_unlock(gc);
 }
 
@@ -306,7 +306,7 @@ static void mvebu_gpio_edge_irq_mask(struct irq_data *d)
 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 	struct mvebu_gpio_chip *mvchip = gc->private;
 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
-	u32 mask = 1 << (d->irq - gc->irq_base);
+	u32 mask = d->mask;
 
 	irq_gc_lock(gc);
 	ct->mask_cache_priv &= ~mask;
@@ -320,8 +320,7 @@ static void mvebu_gpio_edge_irq_unmask(struct irq_data *d)
 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 	struct mvebu_gpio_chip *mvchip = gc->private;
 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
-
-	u32 mask = 1 << (d->irq - gc->irq_base);
+	u32 mask = d->mask;
 
 	irq_gc_lock(gc);
 	ct->mask_cache_priv |= mask;
@@ -334,8 +333,7 @@ static void mvebu_gpio_level_irq_mask(struct irq_data *d)
 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 	struct mvebu_gpio_chip *mvchip = gc->private;
 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
-
-	u32 mask = 1 << (d->irq - gc->irq_base);
+	u32 mask = d->mask;
 
 	irq_gc_lock(gc);
 	ct->mask_cache_priv &= ~mask;
@@ -348,8 +346,7 @@ static void mvebu_gpio_level_irq_unmask(struct irq_data *d)
 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 	struct mvebu_gpio_chip *mvchip = gc->private;
 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
-
-	u32 mask = 1 << (d->irq - gc->irq_base);
+	u32 mask = d->mask;
 
 	irq_gc_lock(gc);
 	ct->mask_cache_priv |= mask;
@@ -464,7 +461,7 @@ static void mvebu_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
 	for (i = 0; i < mvchip->chip.ngpio; i++) {
 		int irq;
 
-		irq = mvchip->irqbase + i;
+		irq = irq_find_mapping(mvchip->domain, i);
 
 		if (!(cause & (1 << i)))
 			continue;
@@ -572,8 +569,10 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
 	struct irq_chip_type *ct;
 	struct clk *clk;
 	unsigned int ngpios;
+	bool have_irqs;
 	int soc_variant;
 	int i, cpu, id;
+	int err;
 
 	match = of_match_device(mvebu_gpio_of_match, &pdev->dev);
 	if (match)
@@ -581,6 +580,9 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
 	else
 		soc_variant = MVEBU_GPIO_SOC_VARIANT_ORION;
 
+	/* Some gpio controllers do not provide irq support */
+	have_irqs = of_irq_count(np) != 0;
+
 	mvchip = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_gpio_chip), GFP_KERNEL);
 	if (!mvchip)
 		return -ENOMEM;
@@ -610,6 +612,7 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
 	mvchip->chip.get = mvebu_gpio_get;
 	mvchip->chip.direction_output = mvebu_gpio_direction_output;
 	mvchip->chip.set = mvebu_gpio_set;
+	if (have_irqs)
 		mvchip->chip.to_irq = mvebu_gpio_to_irq;
 	mvchip->chip.base = id * MVEBU_MAX_GPIO_PER_BANK;
 	mvchip->chip.ngpio = ngpios;
@@ -671,34 +674,30 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
 	gpiochip_add(&mvchip->chip);
 
 	/* Some gpio controllers do not provide irq support */
-	if (!of_irq_count(np))
+	if (!have_irqs)
 		return 0;
 
-	/* Setup the interrupt handlers. Each chip can have up to 4
-	 * interrupt handlers, with each handler dealing with 8 GPIO
-	 * pins. */
-	for (i = 0; i < 4; i++) {
-		int irq;
-		irq = platform_get_irq(pdev, i);
-		if (irq < 0)
-			continue;
-		irq_set_handler_data(irq, mvchip);
-		irq_set_chained_handler(irq, mvebu_gpio_irq_handler);
-	}
-
-	mvchip->irqbase = irq_alloc_descs(-1, 0, ngpios, -1);
-	if (mvchip->irqbase < 0) {
-		dev_err(&pdev->dev, "no irqs\n");
-		return mvchip->irqbase;
+	mvchip->domain =
+	    irq_domain_add_linear(np, ngpios, &irq_generic_chip_ops, NULL);
+	if (!mvchip->domain) {
+		dev_err(&pdev->dev, "couldn't allocate irq domain %s (DT).\n",
+			mvchip->chip.label);
+		return -ENODEV;
 	}
 
-	gc = irq_alloc_generic_chip("mvebu_gpio_irq", 2, mvchip->irqbase,
-				    mvchip->membase, handle_level_irq);
-	if (!gc) {
-		dev_err(&pdev->dev, "Cannot allocate generic irq_chip\n");
-		return -ENOMEM;
+	err = irq_alloc_domain_generic_chips(
+	    mvchip->domain, ngpios, 2, np->name, handle_level_irq,
+	    IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_LEVEL, 0, 0);
+	if (err) {
+		dev_err(&pdev->dev, "couldn't allocate irq chips %s (DT).\n",
+			mvchip->chip.label);
+		goto err_domain;
 	}
 
+	/* NOTE: The common accessors cannot be used because of the percpu
+	 * access to the mask registers
+	 */
+	gc = irq_get_domain_generic_chip(mvchip->domain, 0);
 	gc->private = mvchip;
 	ct = &gc->chip_types[0];
 	ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
@@ -716,24 +715,25 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
 	ct->handler = handle_edge_irq;
 	ct->chip.name = mvchip->chip.label;
 
-	irq_setup_generic_chip(gc, IRQ_MSK(ngpios), 0,
-			       IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
+	/* Setup the interrupt handlers. Each chip can have up to 4
+	 * interrupt handlers, with each handler dealing with 8 GPIO
+	 * pins.
+	 */
+	for (i = 0; i < 4; i++) {
+		int irq = platform_get_irq(pdev, i);
 
-	/* Setup irq domain on top of the generic chip. */
-	mvchip->domain = irq_domain_add_simple(np, mvchip->chip.ngpio,
-					       mvchip->irqbase,
-					       &irq_domain_simple_ops,
-					       mvchip);
-	if (!mvchip->domain) {
-		dev_err(&pdev->dev, "couldn't allocate irq domain %s (DT).\n",
-			mvchip->chip.label);
-		irq_remove_generic_chip(gc, IRQ_MSK(ngpios), IRQ_NOREQUEST,
-					IRQ_LEVEL | IRQ_NOPROBE);
-		kfree(gc);
-		return -ENODEV;
+		if (irq < 0)
+			continue;
+		irq_set_handler_data(irq, mvchip);
+		irq_set_chained_handler(irq, mvebu_gpio_irq_handler);
 	}
 
 	return 0;
+
+err_domain:
+	irq_domain_remove(mvchip->domain);
+
+	return err;
 }
 
 static struct platform_driver mvebu_gpio_driver = {