[PATCH 1/1] gpio: Provide the STMPE GPIO driver with its own IRQ Domain

[Lee Jones]

The STMPE GPIO driver can be used as an IRQ controller by some
related devices. Here we provide it with its very own IRQ Domain
so that IRQs can be issued dynamically. This will stand the
driver in good stead when it is enabled for Device Tree, as this
it a prerequisite.

Cc: Grant Likely <grant.likely at secretlab.ca>
Signed-off-by: Lee Jones <lee.jones at linaro.org>
---
 drivers/gpio/gpio-stmpe.c |   67 +++++++++++++++++++++++++++------------------
 1 file changed, 41 insertions(+), 26 deletions(-)

diff --git a/drivers/gpio/gpio-stmpe.c b/drivers/gpio/gpio-stmpe.c
index dce3472..0e0471b 100644
--- a/drivers/gpio/gpio-stmpe.c
+++ b/drivers/gpio/gpio-stmpe.c
@@ -11,6 +11,7 @@
 #include <linux/slab.h>
 #include <linux/gpio.h>
 #include <linux/irq.h>
+#include <linux/irqdomain.h>
 #include <linux/interrupt.h>
 #include <linux/mfd/stmpe.h>
 
@@ -28,6 +29,7 @@ struct stmpe_gpio {
 	struct stmpe *stmpe;
 	struct device *dev;
 	struct mutex irq_lock;
+	struct irq_domain *domain;
 
 	int irq_base;
 	unsigned norequest_mask;
@@ -267,38 +269,55 @@ static irqreturn_t stmpe_gpio_irq(int irq, void *dev)
 	return IRQ_HANDLED;
 }
 
-static int __devinit stmpe_gpio_irq_init(struct stmpe_gpio *stmpe_gpio)
+int stmpe_gpio_irq_map(struct irq_domain *d, unsigned int virq,
+		       irq_hw_number_t hwirq)
 {
-	int base = stmpe_gpio->irq_base;
-	int irq;
+	struct stmpe_gpio *stmpe_gpio = d->host_data;
+
+	if (!stmpe_gpio)
+		return -EINVAL;
 
-	for (irq = base; irq < base + stmpe_gpio->chip.ngpio; irq++) {
-		irq_set_chip_data(irq, stmpe_gpio);
-		irq_set_chip_and_handler(irq, &stmpe_gpio_irq_chip,
-					 handle_simple_irq);
-		irq_set_nested_thread(irq, 1);
+	irq_set_chip_data(hwirq, stmpe_gpio);
+	irq_set_chip_and_handler(hwirq, &stmpe_gpio_irq_chip,
+				 handle_simple_irq);
+	irq_set_nested_thread(hwirq, 1);
 #ifdef CONFIG_ARM
-		set_irq_flags(irq, IRQF_VALID);
+	set_irq_flags(hwirq, IRQF_VALID);
 #else
-		irq_set_noprobe(irq);
+	irq_set_noprobe(hwirq);
 #endif
-	}
 
 	return 0;
 }
 
-static void stmpe_gpio_irq_remove(struct stmpe_gpio *stmpe_gpio)
+void stmpe_gpio_irq_unmap(struct irq_domain *d, unsigned int virq)
 {
-	int base = stmpe_gpio->irq_base;
-	int irq;
-
-	for (irq = base; irq < base + stmpe_gpio->chip.ngpio; irq++) {
 #ifdef CONFIG_ARM
-		set_irq_flags(irq, 0);
+	set_irq_flags(virq, 0);
 #endif
-		irq_set_chip_and_handler(irq, NULL, NULL);
-		irq_set_chip_data(irq, NULL);
+	irq_set_chip_and_handler(virq, NULL, NULL);
+	irq_set_chip_data(virq, NULL);
+}
+
+const struct irq_domain_ops stmpe_gpio_irq_simple_ops = {
+	.unmap = stmpe_gpio_irq_unmap,
+	.map = stmpe_gpio_irq_map,
+	.xlate = irq_domain_xlate_twocell,
+};
+
+static int __devinit stmpe_gpio_irq_init(struct stmpe_gpio *stmpe_gpio)
+{
+	int base = stmpe_gpio->irq_base;
+
+	stmpe_gpio->domain = irq_domain_add_simple(NULL,
+				stmpe_gpio->chip.ngpio, base,
+				&stmpe_gpio_irq_simple_ops, stmpe_gpio);
+	if (!stmpe_gpio->domain) {
+		dev_err(stmpe_gpio->dev, "failed to create irqdomain\n");
+		return -ENOSYS;
 	}
+
+	return 0;
 }
 
 static int __devinit stmpe_gpio_probe(struct platform_device *pdev)
@@ -348,7 +367,7 @@ static int __devinit stmpe_gpio_probe(struct platform_device *pdev)
 				IRQF_ONESHOT, "stmpe-gpio", stmpe_gpio);
 		if (ret) {
 			dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
-			goto out_removeirq;
+			goto out_disable;
 		}
 	}
 
@@ -368,9 +387,6 @@ static int __devinit stmpe_gpio_probe(struct platform_device *pdev)
 out_freeirq:
 	if (irq >= 0)
 		free_irq(irq, stmpe_gpio);
-out_removeirq:
-	if (irq >= 0)
-		stmpe_gpio_irq_remove(stmpe_gpio);
 out_disable:
 	stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
 out_free:
@@ -398,10 +414,9 @@ static int __devexit stmpe_gpio_remove(struct platform_device *pdev)
 
 	stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
 
-	if (irq >= 0) {
+	if (irq >= 0)
 		free_irq(irq, stmpe_gpio);
-		stmpe_gpio_irq_remove(stmpe_gpio);
-	}
+
 	platform_set_drvdata(pdev, NULL);
 	kfree(stmpe_gpio);
 
-- 
1.7.9.5