drivers: Introduce AIODEV subsystem

AIODEV/Aiodevice is a analog I/O framework that can be thought of as a
simplified hybrid between 'hwmon' and 'IIO' subsystems of Linux kernel

This commit is very heavily based on 'iodevice' framework proposal
written by Sascha Hauer.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 59 insertions, 0 deletions

diff --git a/include/aiodev.h b/include/aiodev.h
new file mode 100644
index 0000000000..0d4f7a2940
--- /dev/null
+++ b/include/aiodev.h
@@ -0,0 +1,59 @@
+/*
+ * core.c - Code implementing core functionality of AIODEV susbsystem
+ *
+ * Copyright (c) 2015 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
+ * Copyright (c) 2015 Zodiac Inflight Innovation
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __AIODEVICE_H
+#define __AIODEVICE_H
+
+struct aiodevice;
+struct aiochannel {
+	int index;
+	char *unit;
+	struct aiodevice *aiodev;
+
+	int value;
+	char *name;
+};
+
+struct aiodevice {
+	const char *name;
+	int (*read)(struct aiochannel *, int *val);
+	struct device_d dev;
+	struct device_d *hwdev;
+	struct aiochannel **channels;
+	int num_channels;
+	struct list_head list;
+};
+
+int aiodevice_register(struct aiodevice *aiodev);
+
+struct aiochannel *aiochannel_get(struct device_d *dev, int index);
+struct aiochannel *aiochannel_get_by_name(const char *name);
+
+int aiochannel_get_value(struct aiochannel *aiochan, int *value);
+int aiochannel_get_index(struct aiochannel *aiochan);
+
+static inline const char *aiochannel_get_unit(struct aiochannel *aiochan)
+{
+	return aiochan->unit;
+}
+
+extern struct list_head aiodevices;
+#define for_each_aiodevice(aiodevice) list_for_each_entry(aiodevice, &aiodevices, list)
+
+#endif