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parport: add device-model to parport subsystem

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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>
This commit is contained in:
Sudip Mukherjee 2015-05-20 20:56:57 +05:30 committed by Greg Kroah-Hartman
parent 208250dd4c
commit 6fa45a2268
4 changed files with 379 additions and 28 deletions
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4
drivers/parport/parport_pc.c
View File

@ -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);

15
drivers/parport/procfs.c
View File

@ -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

345
drivers/parport/share.c
View File

@ -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);

43
include/linux/parport.h
View File

@ -13,6 +13,7 @@
#include <linux/wait.h>
#include <linux/irqreturn.h>
#include <linux/semaphore.h>
#include <linux/device.h>
#include <asm/ptrace.h>
#include <uapi/linux/parport.h>
@ -145,6 +146,8 @@ struct pardevice {
unsigned int flags;
struct pardevice *next;
struct pardevice *prev;
struct device dev;
bool devmodel;
struct parport_state *state; /* saved status over preemption */
wait_queue_head_t wait_q;
unsigned long int time;
@ -156,6 +159,8 @@ struct pardevice {
void * sysctl_table;
};
#define to_pardevice(n) container_of(n, struct pardevice, dev)
/* IEEE1284 information */
/* IEEE1284 phases. These are exposed to userland through ppdev IOCTL
@ -195,7 +200,7 @@ struct parport {
* This may unfortulately be null if the
* port has a legacy driver.
*/
struct device bus_dev; /* to link with the bus */
struct parport *physport;
/* If this is a non-default mux
parport, i.e. we're a clone of a real
@ -245,15 +250,26 @@ struct parport {
struct parport *slaves[3];
};
#define to_parport_dev(n) container_of(n, struct parport, bus_dev)
#define DEFAULT_SPIN_TIME 500 /* us */
struct parport_driver {
const char *name;
void (*attach) (struct parport *);
void (*detach) (struct parport *);
void (*match_port)(struct parport *);
int (*probe)(struct pardevice *);
struct device_driver driver;
bool devmodel;
struct list_head list;
};
#define to_parport_driver(n) container_of(n, struct parport_driver, driver)
int parport_bus_init(void);
void parport_bus_exit(void);
/* parport_register_port registers a new parallel port at the given
address (if one does not already exist) and returns a pointer to it.
This entails claiming the I/O region, IRQ and DMA. NULL is returned
@ -272,10 +288,20 @@ void parport_announce_port (struct parport *port);
extern void parport_remove_port(struct parport *port);
/* Register a new high-level driver. */
extern int parport_register_driver (struct parport_driver *);
int __must_check __parport_register_driver(struct parport_driver *,
struct module *,
const char *mod_name);
/*
* parport_register_driver must be a macro so that KBUILD_MODNAME can
* be expanded
*/
#define parport_register_driver(driver) \
__parport_register_driver(driver, THIS_MODULE, KBUILD_MODNAME)
/* Unregister a high-level driver. */
extern void parport_unregister_driver (struct parport_driver *);
void parport_unregister_driver(struct parport_driver *);
/* If parport_register_driver doesn't fit your needs, perhaps
* parport_find_xxx does. */
@ -288,6 +314,15 @@ extern irqreturn_t parport_irq_handler(int irq, void *dev_id);
/* Reference counting for ports. */
extern struct parport *parport_get_port (struct parport *);
extern void parport_put_port (struct parport *);
void parport_del_port(struct parport *);
struct pardev_cb {
int (*preempt)(void *);
void (*wakeup)(void *);
void *private;
void (*irq_func)(void *);
unsigned int flags;
};
/* parport_register_device declares that a device is connected to a
port, and tells the kernel all it needs to know.
@ -301,6 +336,10 @@ struct pardevice *parport_register_device(struct parport *port,
void (*irq_func)(void *),
int flags, void *handle);
struct pardevice *
parport_register_dev_model(struct parport *port, const char *name,
const struct pardev_cb *par_dev_cb, int cnt);
/* parport_unregister unlinks a device from the chain. */
extern void parport_unregister_device(struct pardevice *dev);