HSI: hsi: Rework hsi_event interface

Remove custom hack and make use of the notifier chain interfaces for
delivering events from the ports to their associated clients.
Clients that want to receive port events need to register their callbacks
using hsi_register_port_event(). The callbacks can be called in interrupt
context. Use hsi_unregestier_port_event() to undo the registration.

Signed-off-by: Carlos Chinea <carlos.chinea@nokia.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 14 insertions, 11 deletions

diff --git a/include/linux/hsi/hsi.h b/include/linux/hsi/hsi.h
index 7f3b7262a2b6..56fae865e272 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);