forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
1234 lines
34 KiB
1234 lines
34 KiB
/* |
|
* Parallel-port resource manager code. |
|
* |
|
* Authors: David Campbell <[email protected]> |
|
* Tim Waugh <[email protected]> |
|
* Jose Renau <[email protected]> |
|
* Philip Blundell <[email protected]> |
|
* Andrea Arcangeli |
|
* |
|
* based on work by Grant Guenther <[email protected]> |
|
* and Philip Blundell |
|
* |
|
* Any part of this program may be used in documents licensed under |
|
* the GNU Free Documentation License, Version 1.1 or any later version |
|
* published by the Free Software Foundation. |
|
*/ |
|
|
|
#undef PARPORT_DEBUG_SHARING /* undef for production */ |
|
|
|
#include <linux/module.h> |
|
#include <linux/string.h> |
|
#include <linux/threads.h> |
|
#include <linux/parport.h> |
|
#include <linux/delay.h> |
|
#include <linux/errno.h> |
|
#include <linux/interrupt.h> |
|
#include <linux/ioport.h> |
|
#include <linux/kernel.h> |
|
#include <linux/slab.h> |
|
#include <linux/sched/signal.h> |
|
#include <linux/kmod.h> |
|
#include <linux/device.h> |
|
|
|
#include <linux/spinlock.h> |
|
#include <linux/mutex.h> |
|
#include <asm/irq.h> |
|
|
|
#undef PARPORT_PARANOID |
|
|
|
#define PARPORT_DEFAULT_TIMESLICE (HZ/5) |
|
|
|
unsigned long parport_default_timeslice = PARPORT_DEFAULT_TIMESLICE; |
|
int parport_default_spintime = DEFAULT_SPIN_TIME; |
|
|
|
static LIST_HEAD(portlist); |
|
static DEFINE_SPINLOCK(parportlist_lock); |
|
|
|
/* list of all allocated ports, sorted by ->number */ |
|
static LIST_HEAD(all_ports); |
|
static DEFINE_SPINLOCK(full_list_lock); |
|
|
|
static LIST_HEAD(drivers); |
|
|
|
static DEFINE_MUTEX(registration_lock); |
|
|
|
/* What you can do to a port that's gone away.. */ |
|
static void dead_write_lines(struct parport *p, unsigned char b){} |
|
static unsigned char dead_read_lines(struct parport *p) { return 0; } |
|
static unsigned char dead_frob_lines(struct parport *p, unsigned char b, |
|
unsigned char c) { return 0; } |
|
static void dead_onearg(struct parport *p){} |
|
static void dead_initstate(struct pardevice *d, struct parport_state *s) { } |
|
static void dead_state(struct parport *p, struct parport_state *s) { } |
|
static size_t dead_write(struct parport *p, const void *b, size_t l, int f) |
|
{ return 0; } |
|
static size_t dead_read(struct parport *p, void *b, size_t l, int f) |
|
{ return 0; } |
|
static struct parport_operations dead_ops = { |
|
.write_data = dead_write_lines, /* data */ |
|
.read_data = dead_read_lines, |
|
|
|
.write_control = dead_write_lines, /* control */ |
|
.read_control = dead_read_lines, |
|
.frob_control = dead_frob_lines, |
|
|
|
.read_status = dead_read_lines, /* status */ |
|
|
|
.enable_irq = dead_onearg, /* enable_irq */ |
|
.disable_irq = dead_onearg, /* disable_irq */ |
|
|
|
.data_forward = dead_onearg, /* data_forward */ |
|
.data_reverse = dead_onearg, /* data_reverse */ |
|
|
|
.init_state = dead_initstate, /* init_state */ |
|
.save_state = dead_state, |
|
.restore_state = dead_state, |
|
|
|
.epp_write_data = dead_write, /* epp */ |
|
.epp_read_data = dead_read, |
|
.epp_write_addr = dead_write, |
|
.epp_read_addr = dead_read, |
|
|
|
.ecp_write_data = dead_write, /* ecp */ |
|
.ecp_read_data = dead_read, |
|
.ecp_write_addr = dead_write, |
|
|
|
.compat_write_data = dead_write, /* compat */ |
|
.nibble_read_data = dead_read, /* nibble */ |
|
.byte_read_data = dead_read, /* byte */ |
|
|
|
.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 registered 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. */ |
|
static void detach_driver_chain(struct parport *port) |
|
{ |
|
struct parport_driver *drv; |
|
/* 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. */ |
|
static void get_lowlevel_driver(void) |
|
{ |
|
/* |
|
* There is no actual module called this: you should set |
|
* up an alias for modutils. |
|
*/ |
|
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; |
|
} |
|
|
|
/* |
|
* Iterates through all the devices connected to the bus and return 1 |
|
* if the device is a parallel port. |
|
*/ |
|
|
|
static int port_detect(struct device *dev, void *dev_drv) |
|
{ |
|
if (is_parport(dev)) |
|
return 1; |
|
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 |
|
* pointer it must call parport_get_port() to do so. Calling |
|
* parport_register_device() on that port will do this for you. |
|
* |
|
* The driver's detach() function may block. The port that |
|
* detach() is given will be valid for the duration of the |
|
* 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. 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, struct module *owner, |
|
const char *mod_name) |
|
{ |
|
/* 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; |
|
|
|
/* |
|
* check if bus has any parallel port registered, if |
|
* none is found then load the lowlevel driver. |
|
*/ |
|
ret = bus_for_each_dev(&parport_bus_type, NULL, NULL, |
|
port_detect); |
|
if (!ret) |
|
get_lowlevel_driver(); |
|
|
|
mutex_lock(®istration_lock); |
|
if (drv->match_port) |
|
bus_for_each_dev(&parport_bus_type, NULL, drv, |
|
port_check); |
|
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; |
|
} |
|
|
|
/** |
|
* parport_unregister_driver - deregister a parallel port device driver |
|
* @drv: structure describing the driver that was given to |
|
* parport_register_driver() |
|
* |
|
* This should be called by a parallel port device driver that |
|
* has registered itself using parport_register_driver() when it |
|
* is about to be unloaded. |
|
* |
|
* When it returns, the driver's attach() routine will no longer |
|
* be called, and for each port that attach() was called for, the |
|
* detach() routine will have been called. |
|
* |
|
* All the driver's attach() and detach() calls are guaranteed to have |
|
* finished by the time this function returns. |
|
**/ |
|
|
|
void parport_unregister_driver(struct parport_driver *drv) |
|
{ |
|
mutex_lock(®istration_lock); |
|
bus_for_each_dev(&parport_bus_type, NULL, drv, port_detach); |
|
driver_unregister(&drv->driver); |
|
mutex_unlock(®istration_lock); |
|
} |
|
EXPORT_SYMBOL(parport_unregister_driver); |
|
|
|
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); |
|
for (d = 0; d < 5; d++) { |
|
kfree(port->probe_info[d].class_name); |
|
kfree(port->probe_info[d].mfr); |
|
kfree(port->probe_info[d].model); |
|
kfree(port->probe_info[d].cmdset); |
|
kfree(port->probe_info[d].description); |
|
} |
|
|
|
kfree(port->name); |
|
kfree(port); |
|
} |
|
|
|
/** |
|
* parport_get_port - increment a port's reference count |
|
* @port: the port |
|
* |
|
* This ensures that a struct parport pointer remains valid |
|
* until the matching parport_put_port() call. |
|
**/ |
|
|
|
struct parport *parport_get_port(struct parport *port) |
|
{ |
|
struct device *dev = get_device(&port->bus_dev); |
|
|
|
return to_parport_dev(dev); |
|
} |
|
EXPORT_SYMBOL(parport_get_port); |
|
|
|
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. When the reference count reaches |
|
* zero (port is no longer used), free_port is called. |
|
**/ |
|
|
|
void parport_put_port(struct parport *port) |
|
{ |
|
put_device(&port->bus_dev); |
|
} |
|
EXPORT_SYMBOL(parport_put_port); |
|
|
|
/** |
|
* parport_register_port - register a parallel port |
|
* @base: base I/O address |
|
* @irq: IRQ line |
|
* @dma: DMA channel |
|
* @ops: pointer to the port driver's port operations structure |
|
* |
|
* When a parallel port (lowlevel) driver finds a port that |
|
* should be made available to parallel port device drivers, it |
|
* should call parport_register_port(). The @base, @irq, and |
|
* @dma parameters are for the convenience of port drivers, and |
|
* for ports where they aren't meaningful needn't be set to |
|
* anything special. They can be altered afterwards by adjusting |
|
* the relevant members of the parport structure that is returned |
|
* and represents the port. They should not be tampered with |
|
* after calling parport_announce_port, however. |
|
* |
|
* If there are parallel port device drivers in the system that |
|
* have registered themselves using parport_register_driver(), |
|
* they are not told about the port at this time; that is done by |
|
* parport_announce_port(). |
|
* |
|
* The @ops structure is allocated by the caller, and must not be |
|
* deallocated before calling parport_remove_port(). |
|
* |
|
* If there is no memory to allocate a new parport structure, |
|
* this function will return %NULL. |
|
**/ |
|
|
|
struct parport *parport_register_port(unsigned long base, int irq, int dma, |
|
struct parport_operations *ops) |
|
{ |
|
struct list_head *l; |
|
struct parport *tmp; |
|
int num; |
|
int device; |
|
char *name; |
|
int ret; |
|
|
|
tmp = kzalloc(sizeof(struct parport), GFP_KERNEL); |
|
if (!tmp) |
|
return NULL; |
|
|
|
/* Init our structure */ |
|
tmp->base = base; |
|
tmp->irq = irq; |
|
tmp->dma = dma; |
|
tmp->muxport = tmp->daisy = tmp->muxsel = -1; |
|
tmp->modes = 0; |
|
INIT_LIST_HEAD(&tmp->list); |
|
tmp->devices = tmp->cad = NULL; |
|
tmp->flags = 0; |
|
tmp->ops = ops; |
|
tmp->physport = tmp; |
|
memset(tmp->probe_info, 0, 5 * sizeof(struct parport_device_info)); |
|
rwlock_init(&tmp->cad_lock); |
|
spin_lock_init(&tmp->waitlist_lock); |
|
spin_lock_init(&tmp->pardevice_lock); |
|
tmp->ieee1284.mode = IEEE1284_MODE_COMPAT; |
|
tmp->ieee1284.phase = IEEE1284_PH_FWD_IDLE; |
|
sema_init(&tmp->ieee1284.irq, 0); |
|
tmp->spintime = parport_default_spintime; |
|
atomic_set(&tmp->ref_count, 1); |
|
INIT_LIST_HEAD(&tmp->full_list); |
|
|
|
name = kmalloc(15, GFP_KERNEL); |
|
if (!name) { |
|
kfree(tmp); |
|
return NULL; |
|
} |
|
/* Search for the lowest free parport number. */ |
|
|
|
spin_lock(&full_list_lock); |
|
for (l = all_ports.next, num = 0; l != &all_ports; l = l->next, num++) { |
|
struct parport *p = list_entry(l, struct parport, full_list); |
|
if (p->number != num) |
|
break; |
|
} |
|
tmp->portnum = tmp->number = num; |
|
list_add_tail(&tmp->full_list, l); |
|
spin_unlock(&full_list_lock); |
|
|
|
/* |
|
* Now that the portnum is known finish doing the Init. |
|
*/ |
|
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 */ |
|
tmp->probe_info[device].class = PARPORT_CLASS_LEGACY; |
|
|
|
tmp->waithead = tmp->waittail = NULL; |
|
|
|
ret = device_register(&tmp->bus_dev); |
|
if (ret) { |
|
put_device(&tmp->bus_dev); |
|
return NULL; |
|
} |
|
|
|
return tmp; |
|
} |
|
EXPORT_SYMBOL(parport_register_port); |
|
|
|
/** |
|
* parport_announce_port - tell device drivers about a parallel port |
|
* @port: parallel port to announce |
|
* |
|
* After a port driver has registered a parallel port with |
|
* parport_register_port, and performed any necessary |
|
* initialisation or adjustments, it should call |
|
* parport_announce_port() in order to notify all device drivers |
|
* that have called parport_register_driver(). Their attach() |
|
* functions will be called, with @port as the parameter. |
|
**/ |
|
|
|
void parport_announce_port(struct parport *port) |
|
{ |
|
int i; |
|
|
|
#ifdef CONFIG_PARPORT_1284 |
|
/* Analyse the IEEE1284.3 topology of the port. */ |
|
parport_daisy_init(port); |
|
#endif |
|
|
|
if (!port->dev) |
|
pr_warn("%s: fix this legacy no-device port driver!\n", |
|
port->name); |
|
|
|
parport_proc_register(port); |
|
mutex_lock(®istration_lock); |
|
spin_lock_irq(&parportlist_lock); |
|
list_add_tail(&port->list, &portlist); |
|
for (i = 1; i < 3; i++) { |
|
struct parport *slave = port->slaves[i-1]; |
|
if (slave) |
|
list_add_tail(&slave->list, &portlist); |
|
} |
|
spin_unlock_irq(&parportlist_lock); |
|
|
|
/* Let drivers know that new port(s) has arrived. */ |
|
attach_driver_chain(port); |
|
for (i = 1; i < 3; i++) { |
|
struct parport *slave = port->slaves[i-1]; |
|
if (slave) |
|
attach_driver_chain(slave); |
|
} |
|
mutex_unlock(®istration_lock); |
|
} |
|
EXPORT_SYMBOL(parport_announce_port); |
|
|
|
/** |
|
* parport_remove_port - deregister a parallel port |
|
* @port: parallel port to deregister |
|
* |
|
* When a parallel port driver is forcibly unloaded, or a |
|
* parallel port becomes inaccessible, the port driver must call |
|
* this function in order to deal with device drivers that still |
|
* want to use it. |
|
* |
|
* The parport structure associated with the port has its |
|
* operations structure replaced with one containing 'null' |
|
* operations that return errors or just don't do anything. |
|
* |
|
* Any drivers that have registered themselves using |
|
* parport_register_driver() are notified that the port is no |
|
* longer accessible by having their detach() routines called |
|
* with @port as the parameter. |
|
**/ |
|
|
|
void parport_remove_port(struct parport *port) |
|
{ |
|
int i; |
|
|
|
mutex_lock(®istration_lock); |
|
|
|
/* Spread the word. */ |
|
detach_driver_chain(port); |
|
|
|
#ifdef CONFIG_PARPORT_1284 |
|
/* Forget the IEEE1284.3 topology of the port. */ |
|
parport_daisy_fini(port); |
|
for (i = 1; i < 3; i++) { |
|
struct parport *slave = port->slaves[i-1]; |
|
if (!slave) |
|
continue; |
|
detach_driver_chain(slave); |
|
parport_daisy_fini(slave); |
|
} |
|
#endif |
|
|
|
port->ops = &dead_ops; |
|
spin_lock(&parportlist_lock); |
|
list_del_init(&port->list); |
|
for (i = 1; i < 3; i++) { |
|
struct parport *slave = port->slaves[i-1]; |
|
if (slave) |
|
list_del_init(&slave->list); |
|
} |
|
spin_unlock(&parportlist_lock); |
|
|
|
mutex_unlock(®istration_lock); |
|
|
|
parport_proc_unregister(port); |
|
|
|
for (i = 1; i < 3; i++) { |
|
struct parport *slave = port->slaves[i-1]; |
|
if (slave) |
|
parport_put_port(slave); |
|
} |
|
} |
|
EXPORT_SYMBOL(parport_remove_port); |
|
|
|
static void free_pardevice(struct device *dev) |
|
{ |
|
struct pardevice *par_dev = to_pardevice(dev); |
|
|
|
kfree(par_dev->name); |
|
kfree(par_dev); |
|
} |
|
|
|
/** |
|
* parport_register_dev_model - register a device on a parallel port |
|
* @port: port to which the device is attached |
|
* @name: a name to refer to the device |
|
* @par_dev_cb: struct containing callbacks |
|
* @id: device number to be given to the device |
|
* |
|
* 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 struct pardev_cb contains pointer to callbacks. preemption |
|
* callback function, @preempt, is called when this device driver |
|
* has claimed access to the port but another device driver wants |
|
* to use it. It is given, @private, 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, @preempt can be %NULL. |
|
* |
|
* The wake-up ("kick") callback function, @wakeup, 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, @wakeup 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_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 (par_dev_cb->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; |
|
} |
|
} |
|
|
|
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) { |
|
kfree(par_dev->state); |
|
put_device(&par_dev->dev); |
|
goto err_put_port; |
|
} |
|
|
|
/* 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); |
|
kfree(par_dev->state); |
|
device_unregister(&par_dev->dev); |
|
goto err_put_port; |
|
} |
|
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); |
|
if (!test_and_set_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags)) { |
|
port->proc_device = par_dev; |
|
parport_device_proc_register(par_dev); |
|
} |
|
|
|
return par_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 |
|
* |
|
* This undoes the effect of parport_register_device(). |
|
**/ |
|
|
|
void parport_unregister_device(struct pardevice *dev) |
|
{ |
|
struct parport *port; |
|
|
|
#ifdef PARPORT_PARANOID |
|
if (!dev) { |
|
pr_err("%s: passed NULL\n", __func__); |
|
return; |
|
} |
|
#endif |
|
|
|
port = dev->port->physport; |
|
|
|
if (port->proc_device == dev) { |
|
port->proc_device = NULL; |
|
clear_bit(PARPORT_DEVPROC_REGISTERED, &port->devflags); |
|
parport_device_proc_unregister(dev); |
|
} |
|
|
|
if (port->cad == dev) { |
|
printk(KERN_DEBUG "%s: %s forgot to release port\n", |
|
port->name, dev->name); |
|
parport_release(dev); |
|
} |
|
|
|
spin_lock(&port->pardevice_lock); |
|
if (dev->next) |
|
dev->next->prev = dev->prev; |
|
if (dev->prev) |
|
dev->prev->next = dev->next; |
|
else |
|
port->devices = dev->next; |
|
|
|
if (dev->flags & PARPORT_DEV_EXCL) |
|
port->flags &= ~PARPORT_FLAG_EXCL; |
|
|
|
spin_unlock(&port->pardevice_lock); |
|
|
|
/* |
|
* Make sure we haven't left any pointers around in the wait |
|
* list. |
|
*/ |
|
spin_lock_irq(&port->waitlist_lock); |
|
if (dev->waitprev || dev->waitnext || port->waithead == dev) { |
|
if (dev->waitprev) |
|
dev->waitprev->waitnext = dev->waitnext; |
|
else |
|
port->waithead = dev->waitnext; |
|
if (dev->waitnext) |
|
dev->waitnext->waitprev = dev->waitprev; |
|
else |
|
port->waittail = dev->waitprev; |
|
} |
|
spin_unlock_irq(&port->waitlist_lock); |
|
|
|
kfree(dev->state); |
|
device_unregister(&dev->dev); |
|
|
|
module_put(port->ops->owner); |
|
parport_put_port(port); |
|
} |
|
EXPORT_SYMBOL(parport_unregister_device); |
|
|
|
/** |
|
* parport_find_number - find a parallel port by number |
|
* @number: parallel port number |
|
* |
|
* This returns the parallel port with the specified number, or |
|
* %NULL if there is none. |
|
* |
|
* There is an implicit parport_get_port() done already; to throw |
|
* away the reference to the port that parport_find_number() |
|
* gives you, use parport_put_port(). |
|
*/ |
|
|
|
struct parport *parport_find_number(int number) |
|
{ |
|
struct parport *port, *result = NULL; |
|
|
|
if (list_empty(&portlist)) |
|
get_lowlevel_driver(); |
|
|
|
spin_lock(&parportlist_lock); |
|
list_for_each_entry(port, &portlist, list) { |
|
if (port->number == number) { |
|
result = parport_get_port(port); |
|
break; |
|
} |
|
} |
|
spin_unlock(&parportlist_lock); |
|
return result; |
|
} |
|
EXPORT_SYMBOL(parport_find_number); |
|
|
|
/** |
|
* parport_find_base - find a parallel port by base address |
|
* @base: base I/O address |
|
* |
|
* This returns the parallel port with the specified base |
|
* address, or %NULL if there is none. |
|
* |
|
* There is an implicit parport_get_port() done already; to throw |
|
* away the reference to the port that parport_find_base() |
|
* gives you, use parport_put_port(). |
|
*/ |
|
|
|
struct parport *parport_find_base(unsigned long base) |
|
{ |
|
struct parport *port, *result = NULL; |
|
|
|
if (list_empty(&portlist)) |
|
get_lowlevel_driver(); |
|
|
|
spin_lock(&parportlist_lock); |
|
list_for_each_entry(port, &portlist, list) { |
|
if (port->base == base) { |
|
result = parport_get_port(port); |
|
break; |
|
} |
|
} |
|
spin_unlock(&parportlist_lock); |
|
return result; |
|
} |
|
EXPORT_SYMBOL(parport_find_base); |
|
|
|
/** |
|
* parport_claim - claim access to a parallel port device |
|
* @dev: pointer to structure representing a device on the port |
|
* |
|
* This function will not block and so can be used from interrupt |
|
* context. If parport_claim() succeeds in claiming access to |
|
* the port it returns zero and the port is available to use. It |
|
* may fail (returning non-zero) if the port is in use by another |
|
* driver and that driver is not willing to relinquish control of |
|
* the port. |
|
**/ |
|
|
|
int parport_claim(struct pardevice *dev) |
|
{ |
|
struct pardevice *oldcad; |
|
struct parport *port = dev->port->physport; |
|
unsigned long flags; |
|
|
|
if (port->cad == dev) { |
|
pr_info("%s: %s already owner\n", dev->port->name, dev->name); |
|
return 0; |
|
} |
|
|
|
/* Preempt any current device */ |
|
write_lock_irqsave(&port->cad_lock, flags); |
|
oldcad = port->cad; |
|
if (oldcad) { |
|
if (oldcad->preempt) { |
|
if (oldcad->preempt(oldcad->private)) |
|
goto blocked; |
|
port->ops->save_state(port, dev->state); |
|
} else |
|
goto blocked; |
|
|
|
if (port->cad != oldcad) { |
|
/* |
|
* I think we'll actually deadlock rather than |
|
* get here, but just in case.. |
|
*/ |
|
pr_warn("%s: %s released port when preempted!\n", |
|
port->name, oldcad->name); |
|
if (port->cad) |
|
goto blocked; |
|
} |
|
} |
|
|
|
/* Can't fail from now on, so mark ourselves as no longer waiting. */ |
|
if (dev->waiting & 1) { |
|
dev->waiting = 0; |
|
|
|
/* Take ourselves out of the wait list again. */ |
|
spin_lock_irq(&port->waitlist_lock); |
|
if (dev->waitprev) |
|
dev->waitprev->waitnext = dev->waitnext; |
|
else |
|
port->waithead = dev->waitnext; |
|
if (dev->waitnext) |
|
dev->waitnext->waitprev = dev->waitprev; |
|
else |
|
port->waittail = dev->waitprev; |
|
spin_unlock_irq(&port->waitlist_lock); |
|
dev->waitprev = dev->waitnext = NULL; |
|
} |
|
|
|
/* Now we do the change of devices */ |
|
port->cad = dev; |
|
|
|
#ifdef CONFIG_PARPORT_1284 |
|
/* If it's a mux port, select it. */ |
|
if (dev->port->muxport >= 0) { |
|
/* FIXME */ |
|
port->muxsel = dev->port->muxport; |
|
} |
|
|
|
/* If it's a daisy chain device, select it. */ |
|
if (dev->daisy >= 0) { |
|
/* This could be lazier. */ |
|
if (!parport_daisy_select(port, dev->daisy, |
|
IEEE1284_MODE_COMPAT)) |
|
port->daisy = dev->daisy; |
|
} |
|
#endif /* IEEE1284.3 support */ |
|
|
|
/* Restore control registers */ |
|
port->ops->restore_state(port, dev->state); |
|
write_unlock_irqrestore(&port->cad_lock, flags); |
|
dev->time = jiffies; |
|
return 0; |
|
|
|
blocked: |
|
/* |
|
* If this is the first time we tried to claim the port, register an |
|
* interest. This is only allowed for devices sleeping in |
|
* parport_claim_or_block(), or those with a wakeup function. |
|
*/ |
|
|
|
/* The cad_lock is still held for writing here */ |
|
if (dev->waiting & 2 || dev->wakeup) { |
|
spin_lock(&port->waitlist_lock); |
|
if (test_and_set_bit(0, &dev->waiting) == 0) { |
|
/* First add ourselves to the end of the wait list. */ |
|
dev->waitnext = NULL; |
|
dev->waitprev = port->waittail; |
|
if (port->waittail) { |
|
port->waittail->waitnext = dev; |
|
port->waittail = dev; |
|
} else |
|
port->waithead = port->waittail = dev; |
|
} |
|
spin_unlock(&port->waitlist_lock); |
|
} |
|
write_unlock_irqrestore(&port->cad_lock, flags); |
|
return -EAGAIN; |
|
} |
|
EXPORT_SYMBOL(parport_claim); |
|
|
|
/** |
|
* parport_claim_or_block - claim access to a parallel port device |
|
* @dev: pointer to structure representing a device on the port |
|
* |
|
* This behaves like parport_claim(), but will block if necessary |
|
* to wait for the port to be free. A return value of 1 |
|
* indicates that it slept; 0 means that it succeeded without |
|
* needing to sleep. A negative error code indicates failure. |
|
**/ |
|
|
|
int parport_claim_or_block(struct pardevice *dev) |
|
{ |
|
int r; |
|
|
|
/* |
|
* Signal to parport_claim() that we can wait even without a |
|
* wakeup function. |
|
*/ |
|
dev->waiting = 2; |
|
|
|
/* Try to claim the port. If this fails, we need to sleep. */ |
|
r = parport_claim(dev); |
|
if (r == -EAGAIN) { |
|
#ifdef PARPORT_DEBUG_SHARING |
|
printk(KERN_DEBUG "%s: parport_claim() returned -EAGAIN\n", |
|
dev->name); |
|
#endif |
|
/* |
|
* FIXME!!! Use the proper locking for dev->waiting, |
|
* and make this use the "wait_event_interruptible()" |
|
* interfaces. The cli/sti that used to be here |
|
* did nothing. |
|
* |
|
* See also parport_release() |
|
*/ |
|
|
|
/* |
|
* If dev->waiting is clear now, an interrupt |
|
* gave us the port and we would deadlock if we slept. |
|
*/ |
|
if (dev->waiting) { |
|
wait_event_interruptible(dev->wait_q, |
|
!dev->waiting); |
|
if (signal_pending(current)) |
|
return -EINTR; |
|
r = 1; |
|
} else { |
|
r = 0; |
|
#ifdef PARPORT_DEBUG_SHARING |
|
printk(KERN_DEBUG "%s: didn't sleep in parport_claim_or_block()\n", |
|
dev->name); |
|
#endif |
|
} |
|
|
|
#ifdef PARPORT_DEBUG_SHARING |
|
if (dev->port->physport->cad != dev) |
|
printk(KERN_DEBUG "%s: exiting parport_claim_or_block but %s owns port!\n", |
|
dev->name, dev->port->physport->cad ? |
|
dev->port->physport->cad->name : "nobody"); |
|
#endif |
|
} |
|
dev->waiting = 0; |
|
return r; |
|
} |
|
EXPORT_SYMBOL(parport_claim_or_block); |
|
|
|
/** |
|
* parport_release - give up access to a parallel port device |
|
* @dev: pointer to structure representing parallel port device |
|
* |
|
* This function cannot fail, but it should not be called without |
|
* the port claimed. Similarly, if the port is already claimed |
|
* you should not try claiming it again. |
|
**/ |
|
|
|
void parport_release(struct pardevice *dev) |
|
{ |
|
struct parport *port = dev->port->physport; |
|
struct pardevice *pd; |
|
unsigned long flags; |
|
|
|
/* Make sure that dev is the current device */ |
|
write_lock_irqsave(&port->cad_lock, flags); |
|
if (port->cad != dev) { |
|
write_unlock_irqrestore(&port->cad_lock, flags); |
|
pr_warn("%s: %s tried to release parport when not owner\n", |
|
port->name, dev->name); |
|
return; |
|
} |
|
|
|
#ifdef CONFIG_PARPORT_1284 |
|
/* If this is on a mux port, deselect it. */ |
|
if (dev->port->muxport >= 0) { |
|
/* FIXME */ |
|
port->muxsel = -1; |
|
} |
|
|
|
/* If this is a daisy device, deselect it. */ |
|
if (dev->daisy >= 0) { |
|
parport_daisy_deselect_all(port); |
|
port->daisy = -1; |
|
} |
|
#endif |
|
|
|
port->cad = NULL; |
|
write_unlock_irqrestore(&port->cad_lock, flags); |
|
|
|
/* Save control registers */ |
|
port->ops->save_state(port, dev->state); |
|
|
|
/* |
|
* If anybody is waiting, find out who's been there longest and |
|
* then wake them up. (Note: no locking required) |
|
*/ |
|
/* !!! LOCKING IS NEEDED HERE */ |
|
for (pd = port->waithead; pd; pd = pd->waitnext) { |
|
if (pd->waiting & 2) { /* sleeping in claim_or_block */ |
|
parport_claim(pd); |
|
if (waitqueue_active(&pd->wait_q)) |
|
wake_up_interruptible(&pd->wait_q); |
|
return; |
|
} else if (pd->wakeup) { |
|
pd->wakeup(pd->private); |
|
if (dev->port->cad) /* racy but no matter */ |
|
return; |
|
} else { |
|
pr_err("%s: don't know how to wake %s\n", |
|
port->name, pd->name); |
|
} |
|
} |
|
|
|
/* |
|
* Nobody was waiting, so walk the list to see if anyone is |
|
* interested in being woken up. (Note: no locking required) |
|
*/ |
|
/* !!! LOCKING IS NEEDED HERE */ |
|
for (pd = port->devices; !port->cad && pd; pd = pd->next) { |
|
if (pd->wakeup && pd != dev) |
|
pd->wakeup(pd->private); |
|
} |
|
} |
|
EXPORT_SYMBOL(parport_release); |
|
|
|
irqreturn_t parport_irq_handler(int irq, void *dev_id) |
|
{ |
|
struct parport *port = dev_id; |
|
|
|
parport_generic_irq(port); |
|
|
|
return IRQ_HANDLED; |
|
} |
|
EXPORT_SYMBOL(parport_irq_handler); |
|
|
|
MODULE_LICENSE("GPL");
|
|
|