From: Sudip Mukherjee Date: Wed, 20 May 2015 15:26:57 +0000 (+0530) Subject: parport: add device-model to parport subsystem X-Git-Tag: firefly_0821_release~176^2~1547^2~34 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=6fa45a22689722dac9f0e90c0931d4b34b334ede;p=firefly-linux-kernel-4.4.55.git 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 Tested-by: Alan Cox Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman --- 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 #include #include +#include #include @@ -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 #include #include +#include #include #include @@ -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); diff --git a/include/linux/parport.h b/include/linux/parport.h index c22f12547324..58e3c64c6b49 100644 --- a/include/linux/parport.h +++ b/include/linux/parport.h @@ -13,6 +13,7 @@ #include #include #include +#include #include #include @@ -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);