diff options
Diffstat (limited to 'drivers/parport/share.c')
-rw-r--r-- | drivers/parport/share.c | 345 |
1 files changed, 322 insertions, 23 deletions
diff --git a/drivers/parport/share.c b/drivers/parport/share.c index 3fa6624..697c6d7 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(®istration_lock); - list_for_each_entry(port, &portlist, list) - drv->attach(port); - list_add(&drv->list, &drivers); - mutex_unlock(®istration_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(®istration_lock); + if (drv->match_port) + bus_for_each_dev(&parport_bus_type, NULL, drv, + port_check); + mutex_unlock(®istration_lock); + } else { + struct parport *port; + + drv->devmodel = false; + + mutex_lock(®istration_lock); + list_for_each_entry(port, &portlist, list) + drv->attach(port); + list_add(&drv->list, &drivers); + mutex_unlock(®istration_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(®istration_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(®istration_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); |