Staging: iio: iio-trig-gpio: Remove redundant gpio_request

Remove redundant gpio_request:
The GPIO used as trigger IRQ, is also requested as gpio, but actually never read.

Use platform resource facility to get IRQs numbers and flags.
Make sure this driver can be used with any system IRQ, not necessarily limited to GPIO-IRQs.
Use dev_err(dev...) and friends instead of printk(KERN_ERR...)
Signed-off-by: Michael Hennerich <Michael.Hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/trigger/iio-trig-gpio.c

@@ -13,7 +13,6 @@
  * TODO:
  *
  * Add board config elements to allow specification of startup settings.
- * Add configuration settings (irq type etc)
  */
 
 #include <linux/kernel.h>
@@ -31,7 +30,7 @@ DEFINE_MUTEX(iio_gpio_trigger_list_lock);
 
 struct iio_gpio_trigger_info {
 	struct mutex in_use;
-	int gpio;
+	unsigned int irq;
 };
 /*
  * Need to reference count these triggers and only enable gpio interrupts
@@ -58,19 +57,27 @@ static const struct attribute_group iio_gpio_trigger_attr_group = {
 	.attrs = iio_gpio_trigger_attrs,
 };
 
-static int iio_gpio_trigger_probe(struct platform_device *dev)
+static int iio_gpio_trigger_probe(struct platform_device *pdev)
 {
-	int *pdata = dev->dev.platform_data;
 	struct iio_gpio_trigger_info *trig_info;
 	struct iio_trigger *trig, *trig2;
-	int i, irq, ret = 0;
-	if (!pdata) {
-		printk(KERN_ERR "No IIO gpio trigger platform data found\n");
-		goto error_ret;
-	}
-	for (i = 0;; i++) {
-		if (!gpio_is_valid(pdata[i]))
+	unsigned long irqflags;
+	struct resource *irq_res;
+	int irq, ret = 0, irq_res_cnt = 0;
+
+	do {
+		irq_res = platform_get_resource(pdev,
+				IORESOURCE_IRQ, irq_res_cnt);
+
+		if (irq_res == NULL) {
+			if (irq_res_cnt == 0)
+				dev_err(&pdev->dev, "No GPIO IRQs specified");
 			break;
+		}
+		irqflags = (irq_res->flags & IRQF_TRIGGER_MASK) | IRQF_SHARED;
+
+		for (irq = irq_res->start; irq <= irq_res->end; irq++) {
+
 			trig = iio_allocate_trigger();
 			if (!trig) {
 				ret = -ENOMEM;
@@ -84,52 +91,43 @@ static int iio_gpio_trigger_probe(struct platform_device *dev)
 			}
 			trig->control_attrs = &iio_gpio_trigger_attr_group;
 			trig->private_data = trig_info;
-		trig_info->gpio = pdata[i];
+			trig_info->irq = irq;
 			trig->owner = THIS_MODULE;
-		trig->name = kmalloc(IIO_TRIGGER_NAME_LENGTH, GFP_KERNEL);
+			trig->name = kmalloc(IIO_TRIGGER_NAME_LENGTH,
+					GFP_KERNEL);
 			if (!trig->name) {
 				ret = -ENOMEM;
 				goto error_free_trig_info;
 			}
 			snprintf((char *)trig->name,
 				 IIO_TRIGGER_NAME_LENGTH,
-			 "gpiotrig%d",
-			 pdata[i]);
-		ret = gpio_request(trig_info->gpio, trig->name);
-		if (ret)
-			goto error_free_name;
-
-		ret = gpio_direction_input(trig_info->gpio);
-		if (ret)
-			goto error_release_gpio;
-
-		irq = gpio_to_irq(trig_info->gpio);
-		if (irq < 0) {
-			ret = irq;
-			goto error_release_gpio;
-		}
+				 "irqtrig%d", irq);
 
 			ret = request_irq(irq, iio_gpio_trigger_poll,
-				  IRQF_TRIGGER_RISING,
-				  trig->name,
-				  trig);
-		if (ret)
-			goto error_release_gpio;
+					  irqflags, trig->name, trig);
+			if (ret) {
+				dev_err(&pdev->dev,
+					"request IRQ-%d failed", irq);
+				goto error_free_name;
+			}
 
 			ret = iio_trigger_register(trig);
 			if (ret)
 				goto error_release_irq;
 
-		list_add_tail(&trig->alloc_list, &iio_gpio_trigger_list);
-
+			list_add_tail(&trig->alloc_list,
+					&iio_gpio_trigger_list);
 		}
+
+		irq_res_cnt++;
+	} while (irq_res != NULL);
+
+
 	return 0;
 
 /* First clean up the partly allocated trigger */
 error_release_irq:
 	free_irq(irq, trig);
-error_release_gpio:
-	gpio_free(trig_info->gpio);
 error_free_name:
 	kfree(trig->name);
 error_free_trig_info:
@@ -143,18 +141,16 @@ static int iio_gpio_trigger_probe(struct platform_device *dev)
 				 &iio_gpio_trigger_list,
 				 alloc_list) {
 		trig_info = trig->private_data;
-		free_irq(gpio_to_irq(trig_info->gpio), trig);
-		gpio_free(trig_info->gpio);
+		free_irq(gpio_to_irq(trig_info->irq), trig);
 		kfree(trig->name);
 		kfree(trig_info);
 		iio_trigger_unregister(trig);
 	}
 
-error_ret:
 	return ret;
 }
 
-static int iio_gpio_trigger_remove(struct platform_device *dev)
+static int iio_gpio_trigger_remove(struct platform_device *pdev)
 {
 	struct iio_trigger *trig, *trig2;
 	struct iio_gpio_trigger_info *trig_info;
@@ -166,8 +162,7 @@ static int iio_gpio_trigger_remove(struct platform_device *dev)
 				 alloc_list) {
 		trig_info = trig->private_data;
 		iio_trigger_unregister(trig);
-		free_irq(gpio_to_irq(trig_info->gpio), trig);
-		gpio_free(trig_info->gpio);
+		free_irq(trig_info->irq, trig);
 		kfree(trig->name);
 		kfree(trig_info);
 		iio_put_trigger(trig);