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authorSascha Hauer <s.hauer@pengutronix.de>2016-05-16 09:45:56 -0700
committerSascha Hauer <s.hauer@pengutronix.de>2016-05-18 07:47:46 +0200
commit914480a542aabd56ba5220afe0e234fd8213411e (patch)
treeff46c8b566612f54265f8fcedbe2e2d15179ede2 /drivers/aiodev
parente9add3ae570a381568fb4851a3a43f0b5ca3b089 (diff)
downloadbarebox-914480a542aabd56ba5220afe0e234fd8213411e.tar.gz
barebox-914480a542aabd56ba5220afe0e234fd8213411e.tar.xz
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>
Diffstat (limited to 'drivers/aiodev')
-rw-r--r--drivers/aiodev/Kconfig8
-rw-r--r--drivers/aiodev/Makefile2
-rw-r--r--drivers/aiodev/core.c148
3 files changed, 158 insertions, 0 deletions
diff --git a/drivers/aiodev/Kconfig b/drivers/aiodev/Kconfig
new file mode 100644
index 0000000000..d6d4ac05a0
--- /dev/null
+++ b/drivers/aiodev/Kconfig
@@ -0,0 +1,8 @@
+#
+# Misc strange devices
+#
+menuconfig AIODEV
+ bool "Analog I/O drivers"
+
+if AIODEV
+endif
diff --git a/drivers/aiodev/Makefile b/drivers/aiodev/Makefile
new file mode 100644
index 0000000000..806464ed69
--- /dev/null
+++ b/drivers/aiodev/Makefile
@@ -0,0 +1,2 @@
+
+obj-$(CONFIG_AIODEV) += core.o
diff --git a/drivers/aiodev/core.c b/drivers/aiodev/core.c
new file mode 100644
index 0000000000..79f935d710
--- /dev/null
+++ b/drivers/aiodev/core.c
@@ -0,0 +1,148 @@
+/*
+ * 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
+ * Author: Andrey Smirnov <andrew.smirnov@gmail.com>
+ *
+ * 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.
+ */
+
+#include <common.h>
+#include <aiodev.h>
+#include <linux/list.h>
+#include <malloc.h>
+
+LIST_HEAD(aiodevices);
+EXPORT_SYMBOL(aiodevices);
+
+struct aiochannel *aiochannel_get_by_name(const char *name)
+{
+ struct aiodevice *aiodev;
+ int i;
+
+ list_for_each_entry(aiodev, &aiodevices, list) {
+ for (i = 0; i < aiodev->num_channels; i++)
+ if (!strcmp(name, aiodev->channels[i]->name))
+ return aiodev->channels[i];
+ }
+
+ return ERR_PTR(-ENOENT);
+}
+EXPORT_SYMBOL(aiochannel_get_by_name);
+
+struct aiochannel *aiochannel_get(struct device_d *dev, int index)
+{
+ struct of_phandle_args spec;
+ struct aiodevice *aiodev;
+ int ret, chnum = 0;
+
+ if (!dev->device_node)
+ return ERR_PTR(-EINVAL);
+
+ ret = of_parse_phandle_with_args(dev->device_node,
+ "io-channels",
+ "#io-channel-cells",
+ index, &spec);
+ if (ret)
+ return ERR_PTR(ret);
+
+ list_for_each_entry(aiodev, &aiodevices, list) {
+ if (aiodev->hwdev->device_node == spec.np)
+ goto found;
+ }
+
+ return ERR_PTR(-EPROBE_DEFER);
+
+found:
+ if (spec.args_count)
+ chnum = spec.args[0];
+
+ if (chnum >= aiodev->num_channels)
+ return ERR_PTR(-EINVAL);
+
+ return aiodev->channels[chnum];
+}
+EXPORT_SYMBOL(aiochannel_get);
+
+int aiochannel_get_value(struct aiochannel *aiochan, int *value)
+{
+ struct aiodevice *aiodev = aiochan->aiodev;
+
+ return aiodev->read(aiochan, value);
+}
+EXPORT_SYMBOL(aiochannel_get_value);
+
+int aiochannel_get_index(struct aiochannel *aiochan)
+{
+ return aiochan->index;
+}
+EXPORT_SYMBOL(aiochannel_get_index);
+
+static int aiochannel_param_get_value(struct param_d *p, void *priv)
+{
+ struct aiochannel *aiochan = priv;
+
+ return aiochannel_get_value(aiochan, &aiochan->value);
+}
+
+int aiodevice_register(struct aiodevice *aiodev)
+{
+ int i, ret;
+
+ if (!aiodev->name && aiodev->hwdev &&
+ aiodev->hwdev->device_node) {
+ aiodev->dev.id = DEVICE_ID_SINGLE;
+
+ aiodev->name = of_alias_get(aiodev->hwdev->device_node);
+ if (!aiodev->name)
+ aiodev->name = aiodev->hwdev->device_node->name;
+ }
+
+ if (!aiodev->name) {
+ aiodev->name = "aiodev";
+ aiodev->dev.id = DEVICE_ID_DYNAMIC;
+ }
+
+ strcpy(aiodev->dev.name, aiodev->name);
+
+ aiodev->dev.parent = aiodev->hwdev;
+
+ ret = register_device(&aiodev->dev);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < aiodev->num_channels; i++) {
+ struct aiochannel *aiochan = aiodev->channels[i];
+ char *name;
+
+ aiochan->index = i;
+ aiochan->aiodev = aiodev;
+
+ name = xasprintf("in_value%d_%s", i, aiochan->unit);
+
+ dev_add_param_int(&aiodev->dev, name, NULL,
+ aiochannel_param_get_value,
+ &aiochan->value, "%d", aiochan);
+
+ aiochan->name = xasprintf("%s.%s", aiodev->name, name);
+
+ free(name);
+ }
+
+ list_add_tail(&aiodev->list, &aiodevices);
+
+ return 0;
+}
+EXPORT_SYMBOL(aiodevice_register);