parport: remove unused parport_register_device()

All the drivers that are using parallel port has been converted to use
the new device model api, and parport_register_device() is no longer
used.

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Link: https://lore.kernel.org/r/20200403134325.11523-10-sudipm.mukherjee@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: sudipm-mukherjee

drivers/parport/share.c

@@ -641,198 +641,6 @@ void parport_remove_port(struct parport *port)
 }
 EXPORT_SYMBOL(parport_remove_port);
 
-/**
- *	parport_register_device - register a device on a parallel port
- *	@port: port to which the device is attached
- *	@name: a name to refer to the device
- *	@pf: preemption callback
- *	@kf: kick callback (wake-up)
- *	@irq_func: interrupt handler
- *	@flags: registration flags
- *	@handle: data for callback functions
- *
- *	This function, called by parallel port device drivers,
- *	declares that a device is connected to a port, and tells the
- *	system all it needs to know.
- *
- *	The @name is allocated by the caller and must not be
- *	deallocated until the caller calls @parport_unregister_device
- *	for that device.
- *
- *	The preemption callback function, @pf, is called when this
- *	device driver has claimed access to the port but another
- *	device driver wants to use it.  It is given @handle as its
- *	parameter, and should return zero if it is willing for the
- *	system to release the port to another driver on its behalf.
- *	If it wants to keep control of the port it should return
- *	non-zero, and no action will be taken.  It is good manners for
- *	the driver to try to release the port at the earliest
- *	opportunity after its preemption callback rejects a preemption
- *	attempt.  Note that if a preemption callback is happy for
- *	preemption to go ahead, there is no need to release the port;
- *	it is done automatically.  This function may not block, as it
- *	may be called from interrupt context.  If the device driver
- *	does not support preemption, @pf can be %NULL.
- *
- *	The wake-up ("kick") callback function, @kf, is called when
- *	the port is available to be claimed for exclusive access; that
- *	is, parport_claim() is guaranteed to succeed when called from
- *	inside the wake-up callback function.  If the driver wants to
- *	claim the port it should do so; otherwise, it need not take
- *	any action.  This function may not block, as it may be called
- *	from interrupt context.  If the device driver does not want to
- *	be explicitly invited to claim the port in this way, @kf can
- *	be %NULL.
- *
- *	The interrupt handler, @irq_func, is called when an interrupt
- *	arrives from the parallel port.  Note that if a device driver
- *	wants to use interrupts it should use parport_enable_irq(),
- *	and can also check the irq member of the parport structure
- *	representing the port.
- *
- *	The parallel port (lowlevel) driver is the one that has called
- *	request_irq() and whose interrupt handler is called first.
- *	This handler does whatever needs to be done to the hardware to
- *	acknowledge the interrupt (for PC-style ports there is nothing
- *	special to be done).  It then tells the IEEE 1284 code about
- *	the interrupt, which may involve reacting to an IEEE 1284
- *	event depending on the current IEEE 1284 phase.  After this,
- *	it calls @irq_func.  Needless to say, @irq_func will be called
- *	from interrupt context, and may not block.
- *
- *	The %PARPORT_DEV_EXCL flag is for preventing port sharing, and
- *	so should only be used when sharing the port with other device
- *	drivers is impossible and would lead to incorrect behaviour.
- *	Use it sparingly!  Normally, @flags will be zero.
- *
- *	This function returns a pointer to a structure that represents
- *	the device on the port, or %NULL if there is not enough memory
- *	to allocate space for that structure.
- **/
-
-struct pardevice *
-parport_register_device(struct parport *port, const char *name,
-			int (*pf)(void *), void (*kf)(void *),
-			void (*irq_func)(void *),
-			int flags, void *handle)
-{
-	struct pardevice *tmp;
-
-	if (port->physport->flags & PARPORT_FLAG_EXCL) {
-		/* An exclusive device is registered. */
-		printk(KERN_DEBUG "%s: no more devices allowed\n", port->name);
-		return NULL;
-	}
-
-	if (flags & PARPORT_DEV_LURK) {
-		if (!pf || !kf) {
-			pr_info("%s: refused to register lurking device (%s) without callbacks\n",
-				port->name, name);
-			return NULL;
-		}
-	}
-
-	if (flags & PARPORT_DEV_EXCL) {
-		if (port->physport->devices) {
-			/*
-			 * If a device is already registered and this new
-			 * device wants exclusive access, then no need to
-			 * continue as we can not grant exclusive access to
-			 * this device.
-			 */
-			pr_err("%s: cannot grant exclusive access for device %s\n",
-			       port->name, name);
-			return NULL;
-		}
-	}
-
-	/*
-	 * We up our own module reference count, and that of the port
-	 * on which a device is to be registered, to ensure that
-	 * neither of us gets unloaded while we sleep in (e.g.)
-	 * kmalloc.
-	 */
-	if (!try_module_get(port->ops->owner))
-		return NULL;
-
-	parport_get_port(port);
-
-	tmp = kmalloc(sizeof(struct pardevice), GFP_KERNEL);
-	if (!tmp)
-		goto out;
-
-	tmp->state = kmalloc(sizeof(struct parport_state), GFP_KERNEL);
-	if (!tmp->state)
-		goto out_free_pardevice;
-
-	tmp->name = name;
-	tmp->port = port;
-	tmp->daisy = -1;
-	tmp->preempt = pf;
-	tmp->wakeup = kf;
-	tmp->private = handle;
-	tmp->flags = flags;
-	tmp->irq_func = irq_func;
-	tmp->waiting = 0;
-	tmp->timeout = 5 * HZ;
-	tmp->devmodel = false;
-
-	/* Chain this onto the list */
-	tmp->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 (flags & PARPORT_DEV_EXCL) {
-		if (port->physport->devices) {
-			spin_unlock(&port->physport->pardevice_lock);
-			printk(KERN_DEBUG "%s: cannot grant exclusive access for device %s\n",
-			       port->name, name);
-			goto out_free_all;
-		}
-		port->flags |= PARPORT_FLAG_EXCL;
-	}
-
-	tmp->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 = tmp;
-	port->physport->devices = tmp;
-	spin_unlock(&port->physport->pardevice_lock);
-
-	init_waitqueue_head(&tmp->wait_q);
-	tmp->timeslice = parport_default_timeslice;
-	tmp->waitnext = tmp->waitprev = NULL;
-
-	/*
-	 * This has to be run as last thing since init_state may need other
-	 * pardevice fields. -arca
-	 */
-	port->ops->init_state(tmp, tmp->state);
-	if (!test_and_set_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags)) {
-		port->proc_device = tmp;
-		parport_device_proc_register(tmp);
-	}
-	return tmp;
-
- out_free_all:
-	kfree(tmp->state);
- out_free_pardevice:
-	kfree(tmp);
- out:
-	parport_put_port(port);
-	module_put(port->ops->owner);
-
-	return NULL;
-}
-EXPORT_SYMBOL(parport_register_device);
-
 static void free_pardevice(struct device *dev)
 {
 	struct pardevice *par_dev = to_pardevice(dev);

include/linux/parport.h

@@ -325,18 +325,6 @@ struct pardev_cb {
 	unsigned int flags;
 };
 
-/* parport_register_device declares that a device is connected to a
-   port, and tells the kernel all it needs to know.
-   - pf is the preemption function (may be NULL for no callback)
-   - kf is the wake-up function (may be NULL for no callback)
-   - irq_func is the interrupt handler (may be NULL for no interrupts)
-   - handle is a user pointer that gets handed to callback functions.  */
-struct pardevice *parport_register_device(struct parport *port, 
-			  const char *name,
-			  int (*pf)(void *), void (*kf)(void *),
-			  void (*irq_func)(void *), 
-			  int flags, void *handle);
-
 /*
  * parport_register_dev_model declares that a device is connected to a
  * port, and tells the kernel all it needs to know.