staging: comedi: move out of staging directory

The comedi code came into the kernel back in 2008, but traces its
lifetime to much much earlier.  It's been polished and buffed and
there's really nothing preventing it from being part of the "real"
portion of the kernel.

So move it to drivers/comedi/ as it belongs there.

Many thanks to the hundreds of developers who did the work to make this
happen.

Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: H Hartley Sweeten <hsweeten@visionengravers.com>
Link: https://lore.kernel.org/r/YHauop4u3sP6lz8j@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 261 insertions, 0 deletions

diff --git a/drivers/comedi/kcomedilib/Makefile b/drivers/comedi/kcomedilib/Makefile
new file mode 100644
index 000000000000..8031142a105f
--- /dev/null
+++ b/drivers/comedi/kcomedilib/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+ccflags-$(CONFIG_COMEDI_DEBUG)		:= -DDEBUG
+
+obj-$(CONFIG_COMEDI_KCOMEDILIB)	+= kcomedilib.o
+
+kcomedilib-objs := kcomedilib_main.o
diff --git a/drivers/comedi/kcomedilib/kcomedilib_main.c b/drivers/comedi/kcomedilib/kcomedilib_main.c
new file mode 100644
index 000000000000..df9bba1b69ed
--- /dev/null
+++ b/drivers/comedi/kcomedilib/kcomedilib_main.c
@@ -0,0 +1,255 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * kcomedilib/kcomedilib.c
+ * a comedlib interface for kernel modules
+ *
+ * COMEDI - Linux Control and Measurement Device Interface
+ * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
+ */
+
+#include <linux/module.h>
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/io.h>
+
+#include "../comedi.h"
+#include "../comedilib.h"
+#include "../comedidev.h"
+
+MODULE_AUTHOR("David Schleef <ds@schleef.org>");
+MODULE_DESCRIPTION("Comedi kernel library");
+MODULE_LICENSE("GPL");
+
+struct comedi_device *comedi_open(const char *filename)
+{
+	struct comedi_device *dev, *retval = NULL;
+	unsigned int minor;
+
+	if (strncmp(filename, "/dev/comedi", 11) != 0)
+		return NULL;
+
+	if (kstrtouint(filename + 11, 0, &minor))
+		return NULL;
+
+	if (minor >= COMEDI_NUM_BOARD_MINORS)
+		return NULL;
+
+	dev = comedi_dev_get_from_minor(minor);
+	if (!dev)
+		return NULL;
+
+	down_read(&dev->attach_lock);
+	if (dev->attached)
+		retval = dev;
+	else
+		retval = NULL;
+	up_read(&dev->attach_lock);
+
+	if (!retval)
+		comedi_dev_put(dev);
+
+	return retval;
+}
+EXPORT_SYMBOL_GPL(comedi_open);
+
+int comedi_close(struct comedi_device *dev)
+{
+	comedi_dev_put(dev);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(comedi_close);
+
+static int comedi_do_insn(struct comedi_device *dev,
+			  struct comedi_insn *insn,
+			  unsigned int *data)
+{
+	struct comedi_subdevice *s;
+	int ret;
+
+	mutex_lock(&dev->mutex);
+
+	if (!dev->attached) {
+		ret = -EINVAL;
+		goto error;
+	}
+
+	/* a subdevice instruction */
+	if (insn->subdev >= dev->n_subdevices) {
+		ret = -EINVAL;
+		goto error;
+	}
+	s = &dev->subdevices[insn->subdev];
+
+	if (s->type == COMEDI_SUBD_UNUSED) {
+		dev_err(dev->class_dev,
+			"%d not usable subdevice\n", insn->subdev);
+		ret = -EIO;
+		goto error;
+	}
+
+	/* XXX check lock */
+
+	ret = comedi_check_chanlist(s, 1, &insn->chanspec);
+	if (ret < 0) {
+		dev_err(dev->class_dev, "bad chanspec\n");
+		ret = -EINVAL;
+		goto error;
+	}
+
+	if (s->busy) {
+		ret = -EBUSY;
+		goto error;
+	}
+	s->busy = dev;
+
+	switch (insn->insn) {
+	case INSN_BITS:
+		ret = s->insn_bits(dev, s, insn, data);
+		break;
+	case INSN_CONFIG:
+		/* XXX should check instruction length */
+		ret = s->insn_config(dev, s, insn, data);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	s->busy = NULL;
+error:
+
+	mutex_unlock(&dev->mutex);
+	return ret;
+}
+
+int comedi_dio_get_config(struct comedi_device *dev, unsigned int subdev,
+			  unsigned int chan, unsigned int *io)
+{
+	struct comedi_insn insn;
+	unsigned int data[2];
+	int ret;
+
+	memset(&insn, 0, sizeof(insn));
+	insn.insn = INSN_CONFIG;
+	insn.n = 2;
+	insn.subdev = subdev;
+	insn.chanspec = CR_PACK(chan, 0, 0);
+	data[0] = INSN_CONFIG_DIO_QUERY;
+	data[1] = 0;
+	ret = comedi_do_insn(dev, &insn, data);
+	if (ret >= 0)
+		*io = data[1];
+	return ret;
+}
+EXPORT_SYMBOL_GPL(comedi_dio_get_config);
+
+int comedi_dio_config(struct comedi_device *dev, unsigned int subdev,
+		      unsigned int chan, unsigned int io)
+{
+	struct comedi_insn insn;
+
+	memset(&insn, 0, sizeof(insn));
+	insn.insn = INSN_CONFIG;
+	insn.n = 1;
+	insn.subdev = subdev;
+	insn.chanspec = CR_PACK(chan, 0, 0);
+
+	return comedi_do_insn(dev, &insn, &io);
+}
+EXPORT_SYMBOL_GPL(comedi_dio_config);
+
+int comedi_dio_bitfield2(struct comedi_device *dev, unsigned int subdev,
+			 unsigned int mask, unsigned int *bits,
+			 unsigned int base_channel)
+{
+	struct comedi_insn insn;
+	unsigned int data[2];
+	unsigned int n_chan;
+	unsigned int shift;
+	int ret;
+
+	base_channel = CR_CHAN(base_channel);
+	n_chan = comedi_get_n_channels(dev, subdev);
+	if (base_channel >= n_chan)
+		return -EINVAL;
+
+	memset(&insn, 0, sizeof(insn));
+	insn.insn = INSN_BITS;
+	insn.chanspec = base_channel;
+	insn.n = 2;
+	insn.subdev = subdev;
+
+	data[0] = mask;
+	data[1] = *bits;
+
+	/*
+	 * Most drivers ignore the base channel in insn->chanspec.
+	 * Fix this here if the subdevice has <= 32 channels.
+	 */
+	if (n_chan <= 32) {
+		shift = base_channel;
+		if (shift) {
+			insn.chanspec = 0;
+			data[0] <<= shift;
+			data[1] <<= shift;
+		}
+	} else {
+		shift = 0;
+	}
+
+	ret = comedi_do_insn(dev, &insn, data);
+	*bits = data[1] >> shift;
+	return ret;
+}
+EXPORT_SYMBOL_GPL(comedi_dio_bitfield2);
+
+int comedi_find_subdevice_by_type(struct comedi_device *dev, int type,
+				  unsigned int subd)
+{
+	struct comedi_subdevice *s;
+	int ret = -ENODEV;
+
+	down_read(&dev->attach_lock);
+	if (dev->attached)
+		for (; subd < dev->n_subdevices; subd++) {
+			s = &dev->subdevices[subd];
+			if (s->type == type) {
+				ret = subd;
+				break;
+			}
+		}
+	up_read(&dev->attach_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(comedi_find_subdevice_by_type);
+
+int comedi_get_n_channels(struct comedi_device *dev, unsigned int subdevice)
+{
+	int n;
+
+	down_read(&dev->attach_lock);
+	if (!dev->attached || subdevice >= dev->n_subdevices)
+		n = 0;
+	else
+		n = dev->subdevices[subdevice].n_chan;
+	up_read(&dev->attach_lock);
+
+	return n;
+}
+EXPORT_SYMBOL_GPL(comedi_get_n_channels);
+
+static int __init kcomedilib_module_init(void)
+{
+	return 0;
+}
+
+static void __exit kcomedilib_module_exit(void)
+{
+}
+
+module_init(kcomedilib_module_init);
+module_exit(kcomedilib_module_exit);