staging: comedi: amplc_pc236: split into ISA, PCI and common module

The "amplc_pc236" driver currently handles both ISA and PCI devices and
uses a small amount of conditional compilation depending which are
enabled.

Move most of the functionality into a new module, "amplc_pc236_common",
and split off support for PCI devices into a new module, "amplc_pci236".
Retain support for ISA devices in the existing module, "amplc_pc236".

Since the `detach` handler (`pc236_detach()`) in the existing module
"amplc_pc236" now only needs to handle ISA devices and only calls
`comedi_legacy_detach()`, just use `comedi_legacy_detach()` directly as
the `detach` handler in `struct comedi_driver amplc_pc236_driver`.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 206 insertions, 0 deletions

diff --git a/drivers/staging/comedi/drivers/amplc_pc236_common.c b/drivers/staging/comedi/drivers/amplc_pc236_common.c
new file mode 100644
index 000000000000..18e237cca419
--- /dev/null
+++ b/drivers/staging/comedi/drivers/amplc_pc236_common.c
@@ -0,0 +1,206 @@
+/*
+ * comedi/drivers/amplc_pc236_common.c
+ * Common support code for "amplc_pc236" and "amplc_pci236".
+ *
+ * Copyright (C) 2002-2014 MEV Ltd. <http://www.mev.co.uk/>
+ *
+ * COMEDI - Linux Control and Measurement Device Interface
+ * Copyright (C) 2000 David A. Schleef <ds@schleef.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 <linux/module.h>
+#include <linux/interrupt.h>
+
+#include "../comedidev.h"
+
+#include "amplc_pc236.h"
+#include "comedi_fc.h"
+#include "8255.h"
+
+static void pc236_intr_update(struct comedi_device *dev, bool enable)
+{
+	const struct pc236_board *thisboard = comedi_board(dev);
+	struct pc236_private *devpriv = dev->private;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->spinlock, flags);
+	devpriv->enable_irq = enable;
+	if (thisboard->intr_update_cb)
+		thisboard->intr_update_cb(dev, enable);
+	spin_unlock_irqrestore(&dev->spinlock, flags);
+}
+
+/*
+ * This function is called when an interrupt occurs to check whether
+ * the interrupt has been marked as enabled and was generated by the
+ * board.  If so, the function prepares the hardware for the next
+ * interrupt.
+ * Returns false if the interrupt should be ignored.
+ */
+static bool pc236_intr_check(struct comedi_device *dev)
+{
+	const struct pc236_board *thisboard = comedi_board(dev);
+	struct pc236_private *devpriv = dev->private;
+	bool retval = false;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->spinlock, flags);
+	if (devpriv->enable_irq) {
+		if (thisboard->intr_chk_clr_cb)
+			retval = thisboard->intr_chk_clr_cb(dev);
+		else
+			retval = true;
+	}
+	spin_unlock_irqrestore(&dev->spinlock, flags);
+
+	return retval;
+}
+
+static int pc236_intr_insn(struct comedi_device *dev,
+			   struct comedi_subdevice *s, struct comedi_insn *insn,
+			   unsigned int *data)
+{
+	data[1] = 0;
+	return insn->n;
+}
+
+static int pc236_intr_cmdtest(struct comedi_device *dev,
+			      struct comedi_subdevice *s,
+			      struct comedi_cmd *cmd)
+{
+	int err = 0;
+
+	/* Step 1 : check if triggers are trivially valid */
+
+	err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
+	err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_FOLLOW);
+	err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_NONE);
+
+	if (err)
+		return 1;
+
+	/* Step 2a : make sure trigger sources are unique */
+	/* Step 2b : and mutually compatible */
+
+	if (err)
+		return 2;
+
+	/* Step 3: check it arguments are trivially valid */
+
+	err |= cfc_check_trigger_arg_is(&cmd->start_arg, 0);
+	err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
+	err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
+	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
+	err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
+
+	if (err)
+		return 3;
+
+	/* step 4: ignored */
+
+	if (err)
+		return 4;
+
+	return 0;
+}
+
+static int pc236_intr_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
+{
+	pc236_intr_update(dev, true);
+
+	return 0;
+}
+
+static int pc236_intr_cancel(struct comedi_device *dev,
+			     struct comedi_subdevice *s)
+{
+	pc236_intr_update(dev, false);
+
+	return 0;
+}
+
+static irqreturn_t pc236_interrupt(int irq, void *d)
+{
+	struct comedi_device *dev = d;
+	struct comedi_subdevice *s = dev->read_subdev;
+	bool handled;
+
+	handled = pc236_intr_check(dev);
+	if (dev->attached && handled) {
+		comedi_buf_put(s, 0);
+		s->async->events |= COMEDI_CB_BLOCK | COMEDI_CB_EOS;
+		comedi_event(dev, s);
+	}
+	return IRQ_RETVAL(handled);
+}
+
+int amplc_pc236_common_attach(struct comedi_device *dev, unsigned long iobase,
+			      unsigned int irq, unsigned long req_irq_flags)
+{
+	struct comedi_subdevice *s;
+	int ret;
+
+	dev->iobase = iobase;
+
+	ret = comedi_alloc_subdevices(dev, 2);
+	if (ret)
+		return ret;
+
+	s = &dev->subdevices[0];
+	/* digital i/o subdevice (8255) */
+	ret = subdev_8255_init(dev, s, NULL, iobase);
+	if (ret)
+		return ret;
+
+	s = &dev->subdevices[1];
+	dev->read_subdev = s;
+	s->type = COMEDI_SUBD_UNUSED;
+	pc236_intr_update(dev, false);
+	if (irq) {
+		if (request_irq(irq, pc236_interrupt, req_irq_flags,
+				dev->board_name, dev) >= 0) {
+			dev->irq = irq;
+			s->type = COMEDI_SUBD_DI;
+			s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
+			s->n_chan = 1;
+			s->maxdata = 1;
+			s->range_table = &range_digital;
+			s->insn_bits = pc236_intr_insn;
+			s->len_chanlist	= 1;
+			s->do_cmdtest = pc236_intr_cmdtest;
+			s->do_cmd = pc236_intr_cmd;
+			s->cancel = pc236_intr_cancel;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(amplc_pc236_common_attach);
+
+static int __init amplc_pc236_common_init(void)
+{
+	return 0;
+}
+module_init(amplc_pc236_common_init);
+
+static void __exit amplc_pc236_common_exit(void)
+{
+}
+module_exit(amplc_pc236_common_exit);
+
+
+MODULE_AUTHOR("Comedi http://www.comedi.org");
+MODULE_DESCRIPTION("Comedi helper for amplc_pc236 and amplc_pci236");
+MODULE_LICENSE("GPL");