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authorSudip Mukherjee <sudipm.mukherjee@gmail.com>2015-05-20 20:56:57 +0530
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-06-01 07:08:18 +0900
commit6fa45a22689722dac9f0e90c0931d4b34b334ede (patch)
treed3f766b8771a0004cb21690b55e75f0ce1aba014 /drivers/parport
parent208250dd4c3dd54963db85340cdc5e4c2acef5b5 (diff)
parport: add device-model to parport subsystem
parport subsystem starts using the device-model. Drivers using the device-model has to define devmodel as true and should register the device with parport using parport_register_dev_model(). Tested-by: Jean Delvare <jdelvare@suse.de> Tested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/parport')
-rw-r--r--drivers/parport/parport_pc.c4
-rw-r--r--drivers/parport/procfs.c15
-rw-r--r--drivers/parport/share.c345
3 files changed, 338 insertions, 26 deletions
diff --git a/drivers/parport/parport_pc.c b/drivers/parport/parport_pc.c
index 53d15b30636a..78530d1714dc 100644
--- a/drivers/parport/parport_pc.c
+++ b/drivers/parport/parport_pc.c
@@ -2255,7 +2255,7 @@ out5:
release_region(base+0x3, 5);
release_region(base, 3);
out4:
- parport_put_port(p);
+ parport_del_port(p);
out3:
kfree(priv);
out2:
@@ -2294,7 +2294,7 @@ void parport_pc_unregister_port(struct parport *p)
priv->dma_handle);
#endif
kfree(p->private_data);
- parport_put_port(p);
+ parport_del_port(p);
kfree(ops); /* hope no-one cached it */
}
EXPORT_SYMBOL(parport_pc_unregister_port);
diff --git a/drivers/parport/procfs.c b/drivers/parport/procfs.c
index 3b470801a04f..c776333a68bc 100644
--- a/drivers/parport/procfs.c
+++ b/drivers/parport/procfs.c
@@ -21,6 +21,7 @@
#include <linux/parport.h>
#include <linux/ctype.h>
#include <linux/sysctl.h>
+#include <linux/device.h>
#include <asm/uaccess.h>
@@ -558,8 +559,18 @@ int parport_device_proc_unregister(struct pardevice *device)
static int __init parport_default_proc_register(void)
{
+ int ret;
+
parport_default_sysctl_table.sysctl_header =
register_sysctl_table(parport_default_sysctl_table.dev_dir);
+ if (!parport_default_sysctl_table.sysctl_header)
+ return -ENOMEM;
+ ret = parport_bus_init();
+ if (ret) {
+ unregister_sysctl_table(parport_default_sysctl_table.
+ sysctl_header);
+ return ret;
+ }
return 0;
}
@@ -570,6 +581,7 @@ static void __exit parport_default_proc_unregister(void)
sysctl_header);
parport_default_sysctl_table.sysctl_header = NULL;
}
+ parport_bus_exit();
}
#else /* no sysctl or no procfs*/
@@ -596,11 +608,12 @@ int parport_device_proc_unregister(struct pardevice *device)
static int __init parport_default_proc_register (void)
{
- return 0;
+ return parport_bus_init();
}
static void __exit parport_default_proc_unregister (void)
{
+ parport_bus_exit();
}
#endif
diff --git a/drivers/parport/share.c b/drivers/parport/share.c
index 3fa66244ce32..697c6d7bf0fe 100644
--- a/drivers/parport/share.c
+++ b/drivers/parport/share.c
@@ -29,6 +29,7 @@
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/kmod.h>
+#include <linux/device.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
@@ -100,13 +101,91 @@ static struct parport_operations dead_ops = {
.owner = NULL,
};
+static struct device_type parport_device_type = {
+ .name = "parport",
+};
+
+static int is_parport(struct device *dev)
+{
+ return dev->type == &parport_device_type;
+}
+
+static int parport_probe(struct device *dev)
+{
+ struct parport_driver *drv;
+
+ if (is_parport(dev))
+ return -ENODEV;
+
+ drv = to_parport_driver(dev->driver);
+ if (!drv->probe) {
+ /* if driver has not defined a custom probe */
+ struct pardevice *par_dev = to_pardevice(dev);
+
+ if (strcmp(par_dev->name, drv->name))
+ return -ENODEV;
+ return 0;
+ }
+ /* if driver defined its own probe */
+ return drv->probe(to_pardevice(dev));
+}
+
+static struct bus_type parport_bus_type = {
+ .name = "parport",
+ .probe = parport_probe,
+};
+
+int parport_bus_init(void)
+{
+ return bus_register(&parport_bus_type);
+}
+
+void parport_bus_exit(void)
+{
+ bus_unregister(&parport_bus_type);
+}
+
+/*
+ * iterates through all the drivers registered with the bus and sends the port
+ * details to the match_port callback of the driver, so that the driver can
+ * know about the new port that just regsitered with the bus and decide if it
+ * wants to use this new port.
+ */
+static int driver_check(struct device_driver *dev_drv, void *_port)
+{
+ struct parport *port = _port;
+ struct parport_driver *drv = to_parport_driver(dev_drv);
+
+ if (drv->match_port)
+ drv->match_port(port);
+ return 0;
+}
+
/* Call attach(port) for each registered driver. */
static void attach_driver_chain(struct parport *port)
{
/* caller has exclusive registration_lock */
struct parport_driver *drv;
+
list_for_each_entry(drv, &drivers, list)
drv->attach(port);
+
+ /*
+ * call the driver_check function of the drivers registered in
+ * new device model
+ */
+
+ bus_for_each_drv(&parport_bus_type, NULL, port, driver_check);
+}
+
+static int driver_detach(struct device_driver *_drv, void *_port)
+{
+ struct parport *port = _port;
+ struct parport_driver *drv = to_parport_driver(_drv);
+
+ if (drv->detach)
+ drv->detach(port);
+ return 0;
}
/* Call detach(port) for each registered driver. */
@@ -116,6 +195,13 @@ static void detach_driver_chain(struct parport *port)
/* caller has exclusive registration_lock */
list_for_each_entry(drv, &drivers, list)
drv->detach (port);
+
+ /*
+ * call the detach function of the drivers registered in
+ * new device model
+ */
+
+ bus_for_each_drv(&parport_bus_type, NULL, port, driver_detach);
}
/* Ask kmod for some lowlevel drivers. */
@@ -126,17 +212,39 @@ static void get_lowlevel_driver (void)
request_module ("parport_lowlevel");
}
+/*
+ * iterates through all the devices connected to the bus and sends the device
+ * details to the match_port callback of the driver, so that the driver can
+ * know what are all the ports that are connected to the bus and choose the
+ * port to which it wants to register its device.
+ */
+static int port_check(struct device *dev, void *dev_drv)
+{
+ struct parport_driver *drv = dev_drv;
+
+ /* only send ports, do not send other devices connected to bus */
+ if (is_parport(dev))
+ drv->match_port(to_parport_dev(dev));
+ return 0;
+}
+
/**
* parport_register_driver - register a parallel port device driver
* @drv: structure describing the driver
+ * @owner: owner module of drv
+ * @mod_name: module name string
*
* This can be called by a parallel port device driver in order
* to receive notifications about ports being found in the
* system, as well as ports no longer available.
*
+ * If devmodel is true then the new device model is used
+ * for registration.
+ *
* The @drv structure is allocated by the caller and must not be
* deallocated until after calling parport_unregister_driver().
*
+ * If using the non device model:
* The driver's attach() function may block. The port that
* attach() is given will be valid for the duration of the
* callback, but if the driver wants to take a copy of the
@@ -148,21 +256,57 @@ static void get_lowlevel_driver (void)
* callback, but if the driver wants to take a copy of the
* pointer it must call parport_get_port() to do so.
*
- * Returns 0 on success. Currently it always succeeds.
+ *
+ * Returns 0 on success. The non device model will always succeeds.
+ * but the new device model can fail and will return the error code.
**/
-int parport_register_driver (struct parport_driver *drv)
+int __parport_register_driver(struct parport_driver *drv, struct module *owner,
+ const char *mod_name)
{
- struct parport *port;
-
if (list_empty(&portlist))
get_lowlevel_driver ();
- mutex_lock(&registration_lock);
- list_for_each_entry(port, &portlist, list)
- drv->attach(port);
- list_add(&drv->list, &drivers);
- mutex_unlock(&registration_lock);
+ if (drv->devmodel) {
+ /* using device model */
+ int ret;
+
+ /* initialize common driver fields */
+ drv->driver.name = drv->name;
+ drv->driver.bus = &parport_bus_type;
+ drv->driver.owner = owner;
+ drv->driver.mod_name = mod_name;
+ ret = driver_register(&drv->driver);
+ if (ret)
+ return ret;
+
+ mutex_lock(&registration_lock);
+ if (drv->match_port)
+ bus_for_each_dev(&parport_bus_type, NULL, drv,
+ port_check);
+ mutex_unlock(&registration_lock);
+ } else {
+ struct parport *port;
+
+ drv->devmodel = false;
+
+ mutex_lock(&registration_lock);
+ list_for_each_entry(port, &portlist, list)
+ drv->attach(port);
+ list_add(&drv->list, &drivers);
+ mutex_unlock(&registration_lock);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(__parport_register_driver);
+
+static int port_detach(struct device *dev, void *_drv)
+{
+ struct parport_driver *drv = _drv;
+
+ if (is_parport(dev) && drv->detach)
+ drv->detach(to_parport_dev(dev));
return 0;
}
@@ -189,15 +333,22 @@ void parport_unregister_driver (struct parport_driver *drv)
struct parport *port;
mutex_lock(&registration_lock);
- list_del_init(&drv->list);
- list_for_each_entry(port, &portlist, list)
- drv->detach(port);
+ if (drv->devmodel) {
+ bus_for_each_dev(&parport_bus_type, NULL, drv, port_detach);
+ driver_unregister(&drv->driver);
+ } else {
+ list_del_init(&drv->list);
+ list_for_each_entry(port, &portlist, list)
+ drv->detach(port);
+ }
mutex_unlock(&registration_lock);
}
-static void free_port (struct parport *port)
+static void free_port(struct device *dev)
{
int d;
+ struct parport *port = to_parport_dev(dev);
+
spin_lock(&full_list_lock);
list_del(&port->full_list);
spin_unlock(&full_list_lock);
@@ -223,25 +374,29 @@ static void free_port (struct parport *port)
struct parport *parport_get_port (struct parport *port)
{
- atomic_inc (&port->ref_count);
- return port;
+ struct device *dev = get_device(&port->bus_dev);
+
+ return to_parport_dev(dev);
+}
+
+void parport_del_port(struct parport *port)
+{
+ device_unregister(&port->bus_dev);
}
+EXPORT_SYMBOL(parport_del_port);
/**
* parport_put_port - decrement a port's reference count
* @port: the port
*
* This should be called once for each call to parport_get_port(),
- * once the port is no longer needed.
+ * once the port is no longer needed. When the reference count reaches
+ * zero (port is no longer used), free_port is called.
**/
void parport_put_port (struct parport *port)
{
- if (atomic_dec_and_test (&port->ref_count))
- /* Can destroy it now. */
- free_port (port);
-
- return;
+ put_device(&port->bus_dev);
}
/**
@@ -281,6 +436,7 @@ struct parport *parport_register_port(unsigned long base, int irq, int dma,
int num;
int device;
char *name;
+ int ret;
tmp = kzalloc(sizeof(struct parport), GFP_KERNEL);
if (!tmp) {
@@ -333,6 +489,10 @@ struct parport *parport_register_port(unsigned long base, int irq, int dma,
*/
sprintf(name, "parport%d", tmp->portnum = tmp->number);
tmp->name = name;
+ tmp->bus_dev.bus = &parport_bus_type;
+ tmp->bus_dev.release = free_port;
+ dev_set_name(&tmp->bus_dev, name);
+ tmp->bus_dev.type = &parport_device_type;
for (device = 0; device < 5; device++)
/* assume the worst */
@@ -340,6 +500,12 @@ struct parport *parport_register_port(unsigned long base, int irq, int dma,
tmp->waithead = tmp->waittail = NULL;
+ ret = device_register(&tmp->bus_dev);
+ if (ret) {
+ put_device(&tmp->bus_dev);
+ return NULL;
+ }
+
return tmp;
}
@@ -575,6 +741,7 @@ parport_register_device(struct parport *port, const char *name,
tmp->irq_func = irq_func;
tmp->waiting = 0;
tmp->timeout = 5 * HZ;
+ tmp->devmodel = false;
/* Chain this onto the list */
tmp->prev = NULL;
@@ -630,6 +797,136 @@ parport_register_device(struct parport *port, const char *name,
return NULL;
}
+static void free_pardevice(struct device *dev)
+{
+ struct pardevice *par_dev = to_pardevice(dev);
+
+ kfree(par_dev->name);
+ kfree(par_dev);
+}
+
+struct pardevice *
+parport_register_dev_model(struct parport *port, const char *name,
+ const struct pardev_cb *par_dev_cb, int id)
+{
+ struct pardevice *par_dev;
+ int ret;
+ char *devname;
+
+ if (port->physport->flags & PARPORT_FLAG_EXCL) {
+ /* An exclusive device is registered. */
+ pr_err("%s: no more devices allowed\n", port->name);
+ return NULL;
+ }
+
+ if (par_dev_cb->flags & PARPORT_DEV_LURK) {
+ if (!par_dev_cb->preempt || !par_dev_cb->wakeup) {
+ pr_info("%s: refused to register lurking device (%s) without callbacks\n",
+ port->name, name);
+ return NULL;
+ }
+ }
+
+ if (!try_module_get(port->ops->owner))
+ return NULL;
+
+ parport_get_port(port);
+
+ par_dev = kzalloc(sizeof(*par_dev), GFP_KERNEL);
+ if (!par_dev)
+ goto err_put_port;
+
+ par_dev->state = kzalloc(sizeof(*par_dev->state), GFP_KERNEL);
+ if (!par_dev->state)
+ goto err_put_par_dev;
+
+ devname = kstrdup(name, GFP_KERNEL);
+ if (!devname)
+ goto err_free_par_dev;
+
+ par_dev->name = devname;
+ par_dev->port = port;
+ par_dev->daisy = -1;
+ par_dev->preempt = par_dev_cb->preempt;
+ par_dev->wakeup = par_dev_cb->wakeup;
+ par_dev->private = par_dev_cb->private;
+ par_dev->flags = par_dev_cb->flags;
+ par_dev->irq_func = par_dev_cb->irq_func;
+ par_dev->waiting = 0;
+ par_dev->timeout = 5 * HZ;
+
+ par_dev->dev.parent = &port->bus_dev;
+ par_dev->dev.bus = &parport_bus_type;
+ ret = dev_set_name(&par_dev->dev, "%s.%d", devname, id);
+ if (ret)
+ goto err_free_devname;
+ par_dev->dev.release = free_pardevice;
+ par_dev->devmodel = true;
+ ret = device_register(&par_dev->dev);
+ if (ret)
+ goto err_put_dev;
+
+ /* Chain this onto the list */
+ par_dev->prev = NULL;
+ /*
+ * This function must not run from an irq handler so we don' t need
+ * to clear irq on the local CPU. -arca
+ */
+ spin_lock(&port->physport->pardevice_lock);
+
+ if (par_dev_cb->flags & PARPORT_DEV_EXCL) {
+ if (port->physport->devices) {
+ spin_unlock(&port->physport->pardevice_lock);
+ pr_debug("%s: cannot grant exclusive access for device %s\n",
+ port->name, name);
+ goto err_put_dev;
+ }
+ port->flags |= PARPORT_FLAG_EXCL;
+ }
+
+ par_dev->next = port->physport->devices;
+ wmb(); /*
+ * Make sure that tmp->next is written before it's
+ * added to the list; see comments marked 'no locking
+ * required'
+ */
+ if (port->physport->devices)
+ port->physport->devices->prev = par_dev;
+ port->physport->devices = par_dev;
+ spin_unlock(&port->physport->pardevice_lock);
+
+ init_waitqueue_head(&par_dev->wait_q);
+ par_dev->timeslice = parport_default_timeslice;
+ par_dev->waitnext = NULL;
+ par_dev->waitprev = NULL;
+
+ /*
+ * This has to be run as last thing since init_state may need other
+ * pardevice fields. -arca
+ */
+ port->ops->init_state(par_dev, par_dev->state);
+ port->proc_device = par_dev;
+ parport_device_proc_register(par_dev);
+
+ return par_dev;
+
+err_put_dev:
+ put_device(&par_dev->dev);
+err_free_devname:
+ kfree(devname);
+err_free_par_dev:
+ kfree(par_dev->state);
+err_put_par_dev:
+ if (!par_dev->devmodel)
+ kfree(par_dev);
+err_put_port:
+ parport_put_port(port);
+ module_put(port->ops->owner);
+
+ return NULL;
+}
+EXPORT_SYMBOL(parport_register_dev_model);
+
/**
* parport_unregister_device - deregister a device on a parallel port
* @dev: pointer to structure representing device
@@ -691,7 +988,10 @@ void parport_unregister_device(struct pardevice *dev)
spin_unlock_irq(&port->waitlist_lock);
kfree(dev->state);
- kfree(dev);
+ if (dev->devmodel)
+ device_unregister(&dev->dev);
+ else
+ kfree(dev);
module_put(port->ops->owner);
parport_put_port (port);
@@ -1019,7 +1319,6 @@ EXPORT_SYMBOL(parport_release);
EXPORT_SYMBOL(parport_register_port);
EXPORT_SYMBOL(parport_announce_port);
EXPORT_SYMBOL(parport_remove_port);
-EXPORT_SYMBOL(parport_register_driver);
EXPORT_SYMBOL(parport_unregister_driver);
EXPORT_SYMBOL(parport_register_device);
EXPORT_SYMBOL(parport_unregister_device);

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