Staging: comedi: comedi driver common function module

This module is shared by many comedi drivers.

From: David Schleef <ds@schleef.org>
Cc: Frank Mori Hess <fmhess@users.sourceforge.net>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/comedi/drivers/Makefile

 # Makefile for individual comedi drivers
 #
+
+# Comedi "helper" modules
+obj-$(CONFIG_COMEDI)			+= comedi_fc.o

drivers/staging/comedi/drivers/comedi_fc.c

+/*
+    comedi/drivers/comedi_fc.c
+
+    This is a place for code driver writers wish to share between
+    two or more drivers.  fc is short
+    for frank-common.
+
+    Author:  Frank Mori Hess <fmhess@users.sourceforge.net>
+    Copyright (C) 2002 Frank Mori Hess
+
+    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.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+************************************************************************/
+
+#include "../comedidev.h"
+
+#include "comedi_fc.h"
+
+static void increment_scan_progress(comedi_subdevice * subd,
+	unsigned int num_bytes)
+{
+	comedi_async *async = subd->async;
+	unsigned int scan_length = cfc_bytes_per_scan(subd);
+
+	async->scan_progress += num_bytes;
+	if (async->scan_progress >= scan_length) {
+		async->scan_progress %= scan_length;
+		async->events |= COMEDI_CB_EOS;
+	}
+}
+
+/* Writes an array of data points to comedi's buffer */
+unsigned int cfc_write_array_to_buffer(comedi_subdevice * subd, void *data,
+	unsigned int num_bytes)
+{
+	comedi_async *async = subd->async;
+	unsigned int retval;
+
+	if (num_bytes == 0)
+		return 0;
+
+	retval = comedi_buf_write_alloc(async, num_bytes);
+	if (retval != num_bytes) {
+		rt_printk("comedi: buffer overrun\n");
+		async->events |= COMEDI_CB_OVERFLOW;
+		return 0;
+	}
+
+	comedi_buf_memcpy_to(async, 0, data, num_bytes);
+	comedi_buf_write_free(async, num_bytes);
+	increment_scan_progress(subd, num_bytes);
+	async->events |= COMEDI_CB_BLOCK;
+
+	return num_bytes;
+}
+
+unsigned int cfc_read_array_from_buffer(comedi_subdevice * subd, void *data,
+	unsigned int num_bytes)
+{
+	comedi_async *async = subd->async;
+
+	if (num_bytes == 0)
+		return 0;
+
+	num_bytes = comedi_buf_read_alloc(async, num_bytes);
+	comedi_buf_memcpy_from(async, 0, data, num_bytes);
+	comedi_buf_read_free(async, num_bytes);
+	increment_scan_progress(subd, num_bytes);
+	async->events |= COMEDI_CB_BLOCK;
+
+	return num_bytes;
+}
+
+unsigned int cfc_handle_events(comedi_device * dev, comedi_subdevice * subd)
+{
+	unsigned int events = subd->async->events;
+
+	if (events == 0)
+		return events;
+
+	if (events & (COMEDI_CB_EOA | COMEDI_CB_ERROR | COMEDI_CB_OVERFLOW))
+		subd->cancel(dev, subd);
+
+	comedi_event(dev, subd);
+
+	return events;
+}
+
+MODULE_AUTHOR("Frank Mori Hess <fmhess@users.sourceforge.net>");
+MODULE_DESCRIPTION("Shared functions for Comedi low-level drivers");
+MODULE_LICENSE("GPL");
+
+static int __init comedi_fc_init_module(void)
+{
+	return 0;
+}
+static void __exit comedi_fc_cleanup_module(void)
+{
+}
+
+module_init(comedi_fc_init_module);
+module_exit(comedi_fc_cleanup_module);
+
+EXPORT_SYMBOL(cfc_write_array_to_buffer);
+EXPORT_SYMBOL(cfc_read_array_from_buffer);
+EXPORT_SYMBOL(cfc_handle_events);

drivers/staging/comedi/drivers/comedi_fc.h

+/*
+    comedi_fc.h
+
+    This is a place for code driver writers wish to share between
+    two or more drivers. These functions are meant to be used only
+    by drivers, they are NOT part of the kcomedilib API!
+
+    Author:  Frank Mori Hess <fmhess@users.sourceforge.net>
+    Copyright (C) 2002 Frank Mori Hess
+
+    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.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+************************************************************************/
+
+#ifndef _COMEDI_FC_H
+#define _COMEDI_FC_H
+
+#include "../comedidev.h"
+
+/* Writes an array of data points to comedi's buffer */
+extern unsigned int cfc_write_array_to_buffer(comedi_subdevice * subd,
+	void *data, unsigned int num_bytes);
+
+static inline unsigned int cfc_write_to_buffer(comedi_subdevice * subd,
+	sampl_t data)
+{
+	return cfc_write_array_to_buffer(subd, &data, sizeof(data));
+};
+
+static inline unsigned int cfc_write_long_to_buffer(comedi_subdevice * subd,
+	lsampl_t data)
+{
+	return cfc_write_array_to_buffer(subd, &data, sizeof(data));
+};
+
+extern unsigned int cfc_read_array_from_buffer(comedi_subdevice * subd,
+	void *data, unsigned int num_bytes);
+
+extern unsigned int cfc_handle_events(comedi_device * dev,
+	comedi_subdevice * subd);
+
+static inline unsigned int cfc_bytes_per_scan(comedi_subdevice * subd)
+{
+	int num_samples;
+	int bits_per_sample;
+
+	switch (subd->type) {
+	case COMEDI_SUBD_DI:
+	case COMEDI_SUBD_DO:
+	case COMEDI_SUBD_DIO:
+		bits_per_sample = 8 * bytes_per_sample(subd);
+		num_samples =
+			(subd->async->cmd.chanlist_len + bits_per_sample -
+			1) / bits_per_sample;
+		break;
+	default:
+		num_samples = subd->async->cmd.chanlist_len;
+		break;
+	}
+	return num_samples * bytes_per_sample(subd);
+}
+
+#endif /* _COMEDI_FC_H */

drivers/staging/comedi/drivers/comedi_pci.h

+/*
+    comedi/drivers/comedi_pci.h
+    Various PCI functions for drivers.
+
+    Copyright (C) 2007 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.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef _COMEDI_PCI_H_
+#define _COMEDI_PCI_H_
+
+#include <linux/version.h>
+#include <linux/pci.h>
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
+#define PCI_ENABLE_IS_REFCOUNTED
+#endif
+
+/*
+ * Enables PCI device without requesting regions.  Just a simple wrapper
+ * for pci_enable_device().
+ */
+static inline int comedi_pci_enable_no_regions(struct pci_dev *pdev)
+{
+	return pci_enable_device(pdev);
+}
+
+/*
+ * Called to disable PCI device if PCI device has been enabled, but
+ * PCI regions have not been reserved.
+ *
+ * It only disables the PCI device if the kernel supports reference
+ * counting of PCI enables, otherwise it might stop the device working
+ * in another driver instance.
+ */
+static inline void comedi_pci_disable_no_regions(struct pci_dev *pdev)
+{
+#ifdef PCI_ENABLE_IS_REFCOUNTED
+	pci_disable_device(pdev);
+#endif
+}
+
+/*
+ * Enable the PCI device and request the regions.
+ */
+static inline int comedi_pci_enable(struct pci_dev *pdev, const char *res_name)
+{
+	int rc;
+
+	rc = pci_enable_device(pdev);
+	if (rc < 0) {
+		return rc;
+	}
+	rc = pci_request_regions(pdev, res_name);
+	if (rc < 0) {
+		comedi_pci_disable_no_regions(pdev);
+	}
+	return rc;
+}
+
+/*
+ * Release the regions and disable the PCI device.
+ *
+ * This must be matched with a previous successful call to comedi_pci_enable().
+ */
+static inline void comedi_pci_disable(struct pci_dev *pdev)
+{
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+}
+
+#endif