Merge tag 'staging-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...

[mirror_ubuntu-hirsute-kernel.git] / drivers / staging / comedi / drivers.c

diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
index b3b5125faa728988b1d1efe31e4116df70622cf2..317a821b7906409a5fef8edd6a40b3360945300e 100644 (file)
--- 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 */
@@ -485,6 +540,8 @@ int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
                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);