1 files changed, 167 insertions, 28 deletions

diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
index e25eba5713c..299726f39e2 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;
@@ -83,7 +95,7 @@ int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices)
 }
 EXPORT_SYMBOL_GPL(comedi_alloc_subdevices);
 
-static void cleanup_device(struct comedi_device *dev)
+static void comedi_device_detach_cleanup(struct comedi_device *dev)
 {
 	int i;
 	struct comedi_subdevice *s;
@@ -121,10 +133,14 @@ static void cleanup_device(struct comedi_device *dev)
 
 void comedi_device_detach(struct comedi_device *dev)
 {
+	comedi_device_cancel_all(dev);
+	down_write(&dev->attach_lock);
 	dev->attached = false;
+	dev->detach_count++;
 	if (dev->driver)
 		dev->driver->detach(dev);
-	cleanup_device(dev);
+	comedi_device_detach_cleanup(dev);
+	up_write(&dev->attach_lock);
 }
 
 static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)
@@ -138,6 +154,98 @@ int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
 	return -EINVAL;
 }
 
+/**
+ * comedi_timeout() - busy-wait for a driver condition to occur.
+ * @dev: comedi_device struct
+ * @s: comedi_subdevice struct
+ * @insn: comedi_insn struct
+ * @cb: callback to check for the condition
+ * @context: private context from the driver
+ */
+int comedi_timeout(struct comedi_device *dev,
+		   struct comedi_subdevice *s,
+		   struct comedi_insn *insn,
+		   int (*cb)(struct comedi_device *dev,
+			     struct comedi_subdevice *s,
+			     struct comedi_insn *insn,
+			     unsigned long context),
+		   unsigned long context)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(COMEDI_TIMEOUT_MS);
+	int ret;
+
+	while (time_before(jiffies, timeout)) {
+		ret = cb(dev, s, insn, context);
+		if (ret != -EBUSY)
+			return ret;	/* success (0) or non EBUSY errno */
+		cpu_relax();
+	}
+	return -ETIMEDOUT;
+}
+EXPORT_SYMBOL_GPL(comedi_timeout);
+
+/**
+ * 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);
+
+/**
+ * comedi_dio_update_state() - update the internal state of DIO subdevices.
+ * @s: comedi_subdevice struct
+ * @data: the channel mask and bits to update
+ */
+unsigned int comedi_dio_update_state(struct comedi_subdevice *s,
+				     unsigned int *data)
+{
+	unsigned int chanmask = (s->n_chan < 32) ? ((1 << s->n_chan) - 1)
+						 : 0xffffffff;
+	unsigned int mask = data[0] & chanmask;
+	unsigned int bits = data[1];
+
+	if (mask) {
+		s->state &= ~mask;
+		s->state |= (bits & mask);
+	}
+
+	return mask;
+}
+EXPORT_SYMBOL_GPL(comedi_dio_update_state);
+
 static int insn_rw_emulate_bits(struct comedi_device *dev,
 				struct comedi_subdevice *s,
 				struct comedi_insn *insn, unsigned int *data)
@@ -150,6 +258,7 @@ static int insn_rw_emulate_bits(struct comedi_device *dev,
 	const unsigned base_bitfield_channel =
 	    (chan < channels_per_bitfield) ? 0 : chan;
 	unsigned int new_data[2];
+
 	memset(new_data, 0, sizeof(new_data));
 	memset(&new_insn, 0, sizeof(new_insn));
 	new_insn.insn = INSN_BITS;
@@ -198,7 +307,6 @@ static int __comedi_device_postconfig_async(struct comedi_device *dev,
 		return -ENOMEM;
 
 	init_waitqueue_head(&async->wait_head);
-	async->subdevice = s;
 	s->async = async;
 
 	async->max_bufsize = comedi_default_buf_maxsize_kb * 1024;
@@ -233,6 +341,13 @@ static int __comedi_device_postconfig(struct comedi_device *dev)
 		if (s->type == COMEDI_SUBD_UNUSED)
 			continue;
 
+		if (s->type == COMEDI_SUBD_DO) {
+			if (s->n_chan < 32)
+				s->io_bits = (1 << s->n_chan) - 1;
+			else
+				s->io_bits = 0xffffffff;
+		}
+
 		if (s->len_chanlist == 0)
 			s->len_chanlist = 1;
 
@@ -274,8 +389,9 @@ static int comedi_device_postconfig(struct comedi_device *dev)
 	ret = __comedi_device_postconfig(dev);
 	if (ret < 0)
 		return ret;
-	smp_wmb();
+	down_write(&dev->attach_lock);
 	dev->attached = true;
+	up_write(&dev->attach_lock);
 	return 0;
 }
 
@@ -365,7 +481,7 @@ int comedi_load_firmware(struct comedi_device *dev,
 		release_firmware(fw);
 	}
 
-	return ret;
+	return ret < 0 ? ret : 0;
 }
 EXPORT_SYMBOL_GPL(comedi_load_firmware);
 
@@ -442,6 +558,7 @@ 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 +579,8 @@ 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 +588,8 @@ 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 +601,11 @@ 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;
 }
 
@@ -512,8 +633,12 @@ int comedi_auto_config(struct device *hardware_device,
 	}
 
 	dev = comedi_alloc_board_minor(hardware_device);
-	if (IS_ERR(dev))
+	if (IS_ERR(dev)) {
+		dev_warn(hardware_device,
+			 "driver '%s' could not create device.\n",
+			 driver->driver_name);
 		return PTR_ERR(dev);
+	}
 	/* Note: comedi_alloc_board_minor() locked dev->mutex. */
 
 	dev->driver = driver;
@@ -521,12 +646,22 @@ int comedi_auto_config(struct device *hardware_device,
 	ret = driver->auto_attach(dev, context);
 	if (ret >= 0)
 		ret = comedi_device_postconfig(dev);
-	if (ret < 0)
-		comedi_device_detach(dev);
 	mutex_unlock(&dev->mutex);
 
-	if (ret < 0)
+	if (ret < 0) {
+		dev_warn(hardware_device,
+			 "driver '%s' failed to auto-configure device.\n",
+			 driver->driver_name);
 		comedi_release_hardware_device(hardware_device);
+	} else {
+		/*
+		 * class_dev should be set properly here
+		 *  after a successful auto config
+		 */
+		dev_info(dev->class_dev,
+			 "driver '%s' has successfully auto-configured '%s'.\n",
+			 driver->driver_name, dev->board_name);
+	}
 	return ret;
 }
 EXPORT_SYMBOL_GPL(comedi_auto_config);
@@ -541,21 +676,37 @@ 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);
+		struct comedi_device *dev = comedi_dev_get_from_minor(i);
 
 		if (!dev)
 			continue;
@@ -569,19 +720,7 @@ int comedi_driver_unregister(struct comedi_driver *driver)
 			comedi_device_detach(dev);
 		}
 		mutex_unlock(&dev->mutex);
+		comedi_dev_put(dev);
 	}
-
-	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);