diff options
| -rw-r--r-- | drivers/hsi/hsi.c | 101 | ||||
| -rw-r--r-- | include/linux/hsi/hsi.h | 25 |
2 files changed, 68 insertions, 58 deletions
diff --git a/drivers/hsi/hsi.c b/drivers/hsi/hsi.c index cec1f0c0455..2d58f939d27 100644 --- a/drivers/hsi/hsi.c +++ b/drivers/hsi/hsi.c @@ -21,12 +21,11 @@ */ #include <linux/hsi/hsi.h> #include <linux/compiler.h> -#include <linux/rwsem.h> #include <linux/list.h> -#include <linux/spinlock.h> #include <linux/kobject.h> #include <linux/slab.h> #include <linux/string.h> +#include <linux/notifier.h> #include "hsi_core.h" static ssize_t modalias_show(struct device *dev, @@ -67,7 +66,6 @@ static void hsi_client_release(struct device *dev) static void hsi_new_client(struct hsi_port *port, struct hsi_board_info *info) { struct hsi_client *cl; - unsigned long flags; cl = kzalloc(sizeof(*cl), GFP_KERNEL); if (!cl) @@ -79,9 +77,6 @@ static void hsi_new_client(struct hsi_port *port, struct hsi_board_info *info) cl->device.release = hsi_client_release; dev_set_name(&cl->device, info->name); cl->device.platform_data = info->platform_data; - spin_lock_irqsave(&port->clock, flags); - list_add_tail(&cl->link, &port->clients); - spin_unlock_irqrestore(&port->clock, flags); if (info->archdata) cl->device.archdata = *info->archdata; if (device_register(&cl->device) < 0) { @@ -106,13 +101,6 @@ static void hsi_scan_board_info(struct hsi_controller *hsi) static int hsi_remove_client(struct device *dev, void *data __maybe_unused) { - struct hsi_client *cl = to_hsi_client(dev); - struct hsi_port *port = to_hsi_port(dev->parent); - unsigned long flags; - - spin_lock_irqsave(&port->clock, flags); - list_del(&cl->link); - spin_unlock_irqrestore(&port->clock, flags); device_unregister(dev); return 0; @@ -271,8 +259,7 @@ struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags) port[i]->stop_tx = hsi_dummy_cl; port[i]->release = hsi_dummy_cl; mutex_init(&port[i]->lock); - INIT_LIST_HEAD(&hsi->port[i]->clients); - spin_lock_init(&hsi->port[i]->clock); + ATOMIC_INIT_NOTIFIER_HEAD(&port[i]->n_head); dev_set_name(&port[i]->device, "port%d", i); hsi->port[i]->device.release = hsi_port_release; device_initialize(&hsi->port[i]->device); @@ -420,37 +407,67 @@ void hsi_release_port(struct hsi_client *cl) } EXPORT_SYMBOL_GPL(hsi_release_port); -static int hsi_start_rx(struct hsi_client *cl, void *data __maybe_unused) +static int hsi_event_notifier_call(struct notifier_block *nb, + unsigned long event, void *data __maybe_unused) { - if (cl->hsi_start_rx) - (*cl->hsi_start_rx)(cl); + struct hsi_client *cl = container_of(nb, struct hsi_client, nb); + + (*cl->ehandler)(cl, event); return 0; } -static int hsi_stop_rx(struct hsi_client *cl, void *data __maybe_unused) +/** + * hsi_register_port_event - Register a client to receive port events + * @cl: HSI client that wants to receive port events + * @cb: Event handler callback + * + * Clients should register a callback to be able to receive + * events from the ports. Registration should happen after + * claiming the port. + * The handler can be called in interrupt context. + * + * Returns -errno on error, or 0 on success. + */ +int hsi_register_port_event(struct hsi_client *cl, + void (*handler)(struct hsi_client *, unsigned long)) { - if (cl->hsi_stop_rx) - (*cl->hsi_stop_rx)(cl); + struct hsi_port *port = hsi_get_port(cl); - return 0; + if (!handler || cl->ehandler) + return -EINVAL; + if (!hsi_port_claimed(cl)) + return -EACCES; + cl->ehandler = handler; + cl->nb.notifier_call = hsi_event_notifier_call; + + return atomic_notifier_chain_register(&port->n_head, &cl->nb); } +EXPORT_SYMBOL_GPL(hsi_register_port_event); -static int hsi_port_for_each_client(struct hsi_port *port, void *data, - int (*fn)(struct hsi_client *cl, void *data)) +/** + * hsi_unregister_port_event - Stop receiving port events for a client + * @cl: HSI client that wants to stop receiving port events + * + * Clients should call this function before releasing their associated + * port. + * + * Returns -errno on error, or 0 on success. + */ +int hsi_unregister_port_event(struct hsi_client *cl) { - struct hsi_client *cl; + struct hsi_port *port = hsi_get_port(cl); + int err; - spin_lock(&port->clock); - list_for_each_entry(cl, &port->clients, link) { - spin_unlock(&port->clock); - (*fn)(cl, data); - spin_lock(&port->clock); - } - spin_unlock(&port->clock); + WARN_ON(!hsi_port_claimed(cl)); - return 0; + err = atomic_notifier_chain_unregister(&port->n_head, &cl->nb); + if (!err) + cl->ehandler = NULL; + + return err; } +EXPORT_SYMBOL_GPL(hsi_unregister_port_event); /** * hsi_event -Notifies clients about port events @@ -464,22 +481,12 @@ static int hsi_port_for_each_client(struct hsi_port *port, void *data, * Events: * HSI_EVENT_START_RX - Incoming wake line high * HSI_EVENT_STOP_RX - Incoming wake line down + * + * Returns -errno on error, or 0 on success. */ -void hsi_event(struct hsi_port *port, unsigned int event) +int hsi_event(struct hsi_port *port, unsigned long event) { - int (*fn)(struct hsi_client *cl, void *data); - - switch (event) { - case HSI_EVENT_START_RX: - fn = hsi_start_rx; - break; - case HSI_EVENT_STOP_RX: - fn = hsi_stop_rx; - break; - default: - return; - } - hsi_port_for_each_client(port, NULL, fn); + return atomic_notifier_call_chain(&port->n_head, event, NULL); } EXPORT_SYMBOL_GPL(hsi_event); diff --git a/include/linux/hsi/hsi.h b/include/linux/hsi/hsi.h index 7f3b7262a2b..56fae865e27 100644 --- a/include/linux/hsi/hsi.h +++ b/include/linux/hsi/hsi.h @@ -26,9 +26,9 @@ #include <linux/device.h> #include <linux/mutex.h> #include <linux/scatterlist.h> -#include <linux/spinlock.h> #include <linux/list.h> #include <linux/module.h> +#include <linux/notifier.h> /* HSI message ttype */ #define HSI_MSG_READ 0 @@ -121,18 +121,18 @@ static inline int hsi_register_board_info(struct hsi_board_info const *info, * @device: Driver model representation of the device * @tx_cfg: HSI TX configuration * @rx_cfg: HSI RX configuration - * @hsi_start_rx: Called after incoming wake line goes high - * @hsi_stop_rx: Called after incoming wake line goes low + * @e_handler: Callback for handling port events (RX Wake High/Low) + * @pclaimed: Keeps tracks if the clients claimed its associated HSI port + * @nb: Notifier block for port events */ struct hsi_client { struct device device; struct hsi_config tx_cfg; struct hsi_config rx_cfg; - void (*hsi_start_rx)(struct hsi_client *cl); - void (*hsi_stop_rx)(struct hsi_client *cl); /* private: */ + void (*ehandler)(struct hsi_client *, unsigned long); unsigned int pclaimed:1; - struct list_head link; + struct notifier_block nb; }; #define to_hsi_client(dev) container_of(dev, struct hsi_client, device) @@ -147,6 +147,10 @@ static inline void *hsi_client_drvdata(struct hsi_client *cl) return dev_get_drvdata(&cl->device); } +int hsi_register_port_event(struct hsi_client *cl, + void (*handler)(struct hsi_client *, unsigned long)); +int hsi_unregister_port_event(struct hsi_client *cl); + /** * struct hsi_client_driver - Driver associated to an HSI client * @driver: Driver model representation of the driver @@ -214,8 +218,7 @@ void hsi_free_msg(struct hsi_msg *msg); * @start_tx: Callback to inform that a client wants to TX data * @stop_tx: Callback to inform that a client no longer wishes to TX data * @release: Callback to inform that a client no longer uses the port - * @clients: List of hsi_clients using the port. - * @clock: Lock to serialize access to the clients list. + * @n_head: Notifier chain for signaling port events to the clients. */ struct hsi_port { struct device device; @@ -231,14 +234,14 @@ struct hsi_port { int (*start_tx)(struct hsi_client *cl); int (*stop_tx)(struct hsi_client *cl); int (*release)(struct hsi_client *cl); - struct list_head clients; - spinlock_t clock; + /* private */ + struct atomic_notifier_head n_head; }; #define to_hsi_port(dev) container_of(dev, struct hsi_port, device) #define hsi_get_port(cl) to_hsi_port((cl)->device.parent) -void hsi_event(struct hsi_port *port, unsigned int event); +int hsi_event(struct hsi_port *port, unsigned long event); int hsi_claim_port(struct hsi_client *cl, unsigned int share); void hsi_release_port(struct hsi_client *cl); |