1 files changed, 78 insertions, 18 deletions

diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
index e25eba5713c1..317a821b7906 100644
--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -23,7 +23,6 @@
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/fcntl.h>
-#include <linux/delay.h>
 #include <linux/ioport.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
@@ -39,6 +38,7 @@
 #include "comedi_internal.h"
 
 struct comedi_driver *comedi_drivers;
+DEFINE_MUTEX(comedi_drivers_list_lock);
 
 int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev)
 {
@@ -57,6 +57,18 @@ static void comedi_clear_hw_dev(struct comedi_device *dev)
 	dev->hw_dev = NULL;
 }
 
+/**
+ * comedi_alloc_devpriv() - Allocate memory for the device private data.
+ * @dev: comedi_device struct
+ * @size: size of the memory to allocate
+ */
+void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size)
+{
+	dev->private = kzalloc(size, GFP_KERNEL);
+	return dev->private;
+}
+EXPORT_SYMBOL_GPL(comedi_alloc_devpriv);
+
 int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices)
 {
 	struct comedi_subdevice *s;
@@ -138,6 +150,46 @@ int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
 	return -EINVAL;
 }
 
+/**
+ * comedi_dio_insn_config() - boilerplate (*insn_config) for DIO subdevices.
+ * @dev: comedi_device struct
+ * @s: comedi_subdevice struct
+ * @insn: comedi_insn struct
+ * @data: parameters for the @insn
+ * @mask: io_bits mask for grouped channels
+ */
+int comedi_dio_insn_config(struct comedi_device *dev,
+			   struct comedi_subdevice *s,
+			   struct comedi_insn *insn,
+			   unsigned int *data,
+			   unsigned int mask)
+{
+	unsigned int chan_mask = 1 << CR_CHAN(insn->chanspec);
+
+	if (!mask)
+		mask = chan_mask;
+
+	switch (data[0]) {
+	case INSN_CONFIG_DIO_INPUT:
+		s->io_bits &= ~mask;
+		break;
+
+	case INSN_CONFIG_DIO_OUTPUT:
+		s->io_bits |= mask;
+		break;
+
+	case INSN_CONFIG_DIO_QUERY:
+		data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT;
+		return insn->n;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(comedi_dio_insn_config);
+
 static int insn_rw_emulate_bits(struct comedi_device *dev,
 				struct comedi_subdevice *s,
 				struct comedi_insn *insn, unsigned int *data)
@@ -442,6 +494,7 @@ int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	if (dev->attached)
 		return -EBUSY;
 
+	mutex_lock(&comedi_drivers_list_lock);
 	for (driv = comedi_drivers; driv; driv = driv->next) {
 		if (!try_module_get(driv->module))
 			continue;
@@ -462,7 +515,8 @@ int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 			comedi_report_boards(driv);
 			module_put(driv->module);
 		}
-		return -EIO;
+		ret = -EIO;
+		goto out;
 	}
 	if (driv->attach == NULL) {
 		/* driver does not support manual configuration */
@@ -470,7 +524,8 @@ int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 			 "driver '%s' does not support attach using comedi_config\n",
 			 driv->driver_name);
 		module_put(driv->module);
-		return -ENOSYS;
+		ret = -ENOSYS;
+		goto out;
 	}
 	/* initialize dev->driver here so
 	 * comedi_error() can be called from attach */
@@ -482,9 +537,11 @@ int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 		ret = comedi_device_postconfig(dev);
 	if (ret < 0) {
 		comedi_device_detach(dev);
-		module_put(dev->driver->module);
+		module_put(driv->module);
 	}
 	/* On success, the driver module count has been incremented. */
+out:
+	mutex_unlock(&comedi_drivers_list_lock);
 	return ret;
 }
 
@@ -541,18 +598,34 @@ EXPORT_SYMBOL_GPL(comedi_auto_unconfig);
 
 int comedi_driver_register(struct comedi_driver *driver)
 {
+	mutex_lock(&comedi_drivers_list_lock);
 	driver->next = comedi_drivers;
 	comedi_drivers = driver;
+	mutex_unlock(&comedi_drivers_list_lock);
 
 	return 0;
 }
 EXPORT_SYMBOL_GPL(comedi_driver_register);
 
-int comedi_driver_unregister(struct comedi_driver *driver)
+void comedi_driver_unregister(struct comedi_driver *driver)
 {
 	struct comedi_driver *prev;
 	int i;
 
+	/* unlink the driver */
+	mutex_lock(&comedi_drivers_list_lock);
+	if (comedi_drivers == driver) {
+		comedi_drivers = driver->next;
+	} else {
+		for (prev = comedi_drivers; prev->next; prev = prev->next) {
+			if (prev->next == driver) {
+				prev->next = driver->next;
+				break;
+			}
+		}
+	}
+	mutex_unlock(&comedi_drivers_list_lock);
+
 	/* check for devices using this driver */
 	for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
 		struct comedi_device *dev = comedi_dev_from_minor(i);
@@ -570,18 +643,5 @@ int comedi_driver_unregister(struct comedi_driver *driver)
 		}
 		mutex_unlock(&dev->mutex);
 	}
-
-	if (comedi_drivers == driver) {
-		comedi_drivers = driver->next;
-		return 0;
-	}
-
-	for (prev = comedi_drivers; prev->next; prev = prev->next) {
-		if (prev->next == driver) {
-			prev->next = driver->next;
-			return 0;
-		}
-	}
-	return -EINVAL;
 }
 EXPORT_SYMBOL_GPL(comedi_driver_unregister);