Initial file dump from open source releaseHEADmaster

1 files changed, 167 insertions, 0 deletions

diff --git a/drivers/staging/iio/trigger/iio-trig-gpio.c b/drivers/staging/iio/trigger/iio-trig-gpio.c
new file mode 100644
index 00000000..7c593d18
--- /dev/null
+++ b/drivers/staging/iio/trigger/iio-trig-gpio.c
@@ -0,0 +1,167 @@
+/*
+ * Industrial I/O - gpio based trigger support
+ *
+ * Copyright (c) 2008 Jonathan Cameron
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * Currently this is more of a functioning proof of concept than a full
+ * fledged trigger driver.
+ *
+ * TODO:
+ *
+ * Add board config elements to allow specification of startup settings.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+
+static LIST_HEAD(iio_gpio_trigger_list);
+static DEFINE_MUTEX(iio_gpio_trigger_list_lock);
+
+struct iio_gpio_trigger_info {
+	struct mutex in_use;
+	unsigned int irq;
+};
+/*
+ * Need to reference count these triggers and only enable gpio interrupts
+ * as appropriate.
+ */
+
+/* So what functionality do we want in here?... */
+/* set high / low as interrupt type? */
+
+static irqreturn_t iio_gpio_trigger_poll(int irq, void *private)
+{
+	/* Timestamp not currently provided */
+	iio_trigger_poll(private, 0);
+	return IRQ_HANDLED;
+}
+
+static const struct iio_trigger_ops iio_gpio_trigger_ops = {
+	.owner = THIS_MODULE,
+};
+
+static int iio_gpio_trigger_probe(struct platform_device *pdev)
+{
+	struct iio_gpio_trigger_info *trig_info;
+	struct iio_trigger *trig, *trig2;
+	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_trigger_alloc("irqtrig%d", irq);
+			if (!trig) {
+				ret = -ENOMEM;
+				goto error_free_completed_registrations;
+			}
+
+			trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
+			if (!trig_info) {
+				ret = -ENOMEM;
+				goto error_put_trigger;
+			}
+			iio_trigger_set_drvdata(trig, trig_info);
+			trig_info->irq = irq;
+			trig->ops = &iio_gpio_trigger_ops;
+			ret = request_irq(irq, iio_gpio_trigger_poll,
+					  irqflags, trig->name, trig);
+			if (ret) {
+				dev_err(&pdev->dev,
+					"request IRQ-%d failed", irq);
+				goto error_free_trig_info;
+			}
+
+			ret = iio_trigger_register(trig);
+			if (ret)
+				goto error_release_irq;
+
+			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_free_trig_info:
+	kfree(trig_info);
+error_put_trigger:
+	iio_trigger_put(trig);
+error_free_completed_registrations:
+	/* The rest should have been added to the iio_gpio_trigger_list */
+	list_for_each_entry_safe(trig,
+				 trig2,
+				 &iio_gpio_trigger_list,
+				 alloc_list) {
+		trig_info = iio_trigger_get_drvdata(trig);
+		free_irq(gpio_to_irq(trig_info->irq), trig);
+		kfree(trig_info);
+		iio_trigger_unregister(trig);
+	}
+
+	return ret;
+}
+
+static int iio_gpio_trigger_remove(struct platform_device *pdev)
+{
+	struct iio_trigger *trig, *trig2;
+	struct iio_gpio_trigger_info *trig_info;
+
+	mutex_lock(&iio_gpio_trigger_list_lock);
+	list_for_each_entry_safe(trig,
+				 trig2,
+				 &iio_gpio_trigger_list,
+				 alloc_list) {
+		trig_info = iio_trigger_get_drvdata(trig);
+		iio_trigger_unregister(trig);
+		free_irq(trig_info->irq, trig);
+		kfree(trig_info);
+		iio_trigger_put(trig);
+	}
+	mutex_unlock(&iio_gpio_trigger_list_lock);
+
+	return 0;
+}
+
+static struct platform_driver iio_gpio_trigger_driver = {
+	.probe = iio_gpio_trigger_probe,
+	.remove = iio_gpio_trigger_remove,
+	.driver = {
+		.name = "iio_gpio_trigger",
+		.owner = THIS_MODULE,
+	},
+};
+
+module_platform_driver(iio_gpio_trigger_driver);
+
+MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
+MODULE_DESCRIPTION("Example gpio trigger for the iio subsystem");
+MODULE_LICENSE("GPL v2");