4 files changed, 155 insertions, 120 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-hsi b/Documentation/ABI/testing/sysfs-bus-hsi
new file mode 100644
index 000000000000..1b1b282a99e1
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-hsi
@@ -0,0 +1,19 @@
+What:           /sys/bus/hsi
+Date:           April 2012
+KernelVersion:  3.4
+Contact:        Carlos Chinea <carlos.chinea@nokia.com>
+Description:
+                High Speed Synchronous Serial Interface (HSI) is a
+                serial interface mainly used for connecting application
+                engines (APE) with cellular modem engines (CMT) in cellular
+                handsets.
+                The bus will be populated with devices (hsi_clients) representing
+                the protocols available in the system. Bus drivers implement
+                those protocols.
+
+What:           /sys/bus/hsi/devices/.../modalias
+Date:           April 2012
+KernelVersion:  3.4
+Contact:        Carlos Chinea <carlos.chinea@nokia.com>
+Description:    Stores the same MODALIAS value emitted by uevent
+                Format: hsi:<hsi_client device name>
diff --git a/drivers/hsi/clients/hsi_char.c b/drivers/hsi/clients/hsi_char.c
index 88a050df2389..3ad91f6447d8 100644
--- a/drivers/hsi/clients/hsi_char.c
+++ b/drivers/hsi/clients/hsi_char.c
@@ -123,7 +123,7 @@ struct hsc_client_data {
 static unsigned int hsc_major;
 /* Maximum buffer size that hsi_char will accept from userspace */
 static unsigned int max_data_size = 0x1000;
-module_param(max_data_size, uint, S_IRUSR | S_IWUSR);
+module_param(max_data_size, uint, 0);
 MODULE_PARM_DESC(max_data_size, "max read/write data size [4,8..65536] (^2)");
 
 static void hsc_add_tail(struct hsc_channel *channel, struct hsi_msg *msg,
diff --git a/drivers/hsi/hsi.c b/drivers/hsi/hsi.c
index 4e2d79b79334..2d58f939d27f 100644
--- a/drivers/hsi/hsi.c
+++ b/drivers/hsi/hsi.c
@@ -21,26 +21,13 @@
  */
 #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 struct device_type hsi_ctrl = {
-        .name   = "hsi_controller",
-};
-
-static struct device_type hsi_cl = {
-        .name   = "hsi_client",
-};
-
-static struct device_type hsi_port = {
-        .name   = "hsi_port",
-};
-
 static ssize_t modalias_show(struct device *dev,
                         struct device_attribute *a __maybe_unused, char *buf)
 {
@@ -54,8 +41,7 @@ static struct device_attribute hsi_bus_dev_attrs[] = {
 
 static int hsi_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
-        if (dev->type == &hsi_cl)
-                add_uevent_var(env, "MODALIAS=hsi:%s", dev_name(dev));
+        add_uevent_var(env, "MODALIAS=hsi:%s", dev_name(dev));
 
         return 0;
 }
@@ -80,12 +66,10 @@ 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)
                 return;
-        cl->device.type = &hsi_cl;
         cl->tx_cfg = info->tx_cfg;
         cl->rx_cfg = info->rx_cfg;
         cl->device.bus = &hsi_bus_type;
@@ -93,14 +77,11 @@ 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) {
                 pr_err("hsi: failed to register client: %s\n", info->name);
-                kfree(cl);
+                put_device(&cl->device);
         }
 }
 
@@ -120,13 +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;
@@ -140,12 +114,17 @@ static int hsi_remove_port(struct device *dev, void *data __maybe_unused)
         return 0;
 }
 
-static void hsi_controller_release(struct device *dev __maybe_unused)
+static void hsi_controller_release(struct device *dev)
 {
+        struct hsi_controller *hsi = to_hsi_controller(dev);
+
+        kfree(hsi->port);
+        kfree(hsi);
 }
 
-static void hsi_port_release(struct device *dev __maybe_unused)
+static void hsi_port_release(struct device *dev)
 {
+        kfree(to_hsi_port(dev));
 }
 
 /**
@@ -170,20 +149,12 @@ int hsi_register_controller(struct hsi_controller *hsi)
         unsigned int i;
         int err;
 
-        hsi->device.type = &hsi_ctrl;
-        hsi->device.bus = &hsi_bus_type;
-        hsi->device.release = hsi_controller_release;
-        err = device_register(&hsi->device);
+        err = device_add(&hsi->device);
         if (err < 0)
                 return err;
         for (i = 0; i < hsi->num_ports; i++) {
-                hsi->port[i].device.parent = &hsi->device;
-                hsi->port[i].device.bus = &hsi_bus_type;
-                hsi->port[i].device.release = hsi_port_release;
-                hsi->port[i].device.type = &hsi_port;
-                INIT_LIST_HEAD(&hsi->port[i].clients);
-                spin_lock_init(&hsi->port[i].clock);
-                err = device_register(&hsi->port[i].device);
+                hsi->port[i]->device.parent = &hsi->device;
+                err = device_add(&hsi->port[i]->device);
                 if (err < 0)
                         goto out;
         }
@@ -192,7 +163,9 @@ int hsi_register_controller(struct hsi_controller *hsi)
 
         return 0;
 out:
-        hsi_unregister_controller(hsi);
+        while (i-- > 0)
+                device_del(&hsi->port[i]->device);
+        device_del(&hsi->device);
 
         return err;
 }
@@ -223,6 +196,29 @@ static inline int hsi_dummy_cl(struct hsi_client *cl __maybe_unused)
 }
 
 /**
+ * hsi_put_controller - Free an HSI controller
+ *
+ * @hsi: Pointer to the HSI controller to freed
+ *
+ * HSI controller drivers should only use this function if they need
+ * to free their allocated hsi_controller structures before a successful
+ * call to hsi_register_controller. Other use is not allowed.
+ */
+void hsi_put_controller(struct hsi_controller *hsi)
+{
+        unsigned int i;
+
+        if (!hsi)
+                return;
+
+        for (i = 0; i < hsi->num_ports; i++)
+                if (hsi->port && hsi->port[i])
+                        put_device(&hsi->port[i]->device);
+        put_device(&hsi->device);
+}
+EXPORT_SYMBOL_GPL(hsi_put_controller);
+
+/**
  * hsi_alloc_controller - Allocate an HSI controller and its ports
  * @n_ports: Number of ports on the HSI controller
  * @flags: Kernel allocation flags
@@ -232,55 +228,52 @@ static inline int hsi_dummy_cl(struct hsi_client *cl __maybe_unused)
 struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags)
 {
         struct hsi_controller   *hsi;
-        struct hsi_port         *port;
+        struct hsi_port         **port;
         unsigned int            i;
 
         if (!n_ports)
                 return NULL;
 
-        port = kzalloc(sizeof(*port)*n_ports, flags);
-        if (!port)
-                return NULL;
         hsi = kzalloc(sizeof(*hsi), flags);
         if (!hsi)
-                goto out;
-        for (i = 0; i < n_ports; i++) {
-                dev_set_name(&port[i].device, "port%d", i);
-                port[i].num = i;
-                port[i].async = hsi_dummy_msg;
-                port[i].setup = hsi_dummy_cl;
-                port[i].flush = hsi_dummy_cl;
-                port[i].start_tx = hsi_dummy_cl;
-                port[i].stop_tx = hsi_dummy_cl;
-                port[i].release = hsi_dummy_cl;
-                mutex_init(&port[i].lock);
+                return NULL;
+        port = kzalloc(sizeof(*port)*n_ports, flags);
+        if (!port) {
+                kfree(hsi);
+                return NULL;
         }
         hsi->num_ports = n_ports;
         hsi->port = port;
+        hsi->device.release = hsi_controller_release;
+        device_initialize(&hsi->device);
+
+        for (i = 0; i < n_ports; i++) {
+                port[i] = kzalloc(sizeof(**port), flags);
+                if (port[i] == NULL)
+                        goto out;
+                port[i]->num = i;
+                port[i]->async = hsi_dummy_msg;
+                port[i]->setup = hsi_dummy_cl;
+                port[i]->flush = hsi_dummy_cl;
+                port[i]->start_tx = hsi_dummy_cl;
+                port[i]->stop_tx = hsi_dummy_cl;
+                port[i]->release = hsi_dummy_cl;
+                mutex_init(&port[i]->lock);
+                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);
+        }
 
         return hsi;
 out:
-        kfree(port);
+        hsi_put_controller(hsi);
 
         return NULL;
 }
 EXPORT_SYMBOL_GPL(hsi_alloc_controller);
 
 /**
- * hsi_free_controller - Free an HSI controller
- * @hsi: Pointer to HSI controller
- */
-void hsi_free_controller(struct hsi_controller *hsi)
-{
-        if (!hsi)
-                return;
-
-        kfree(hsi->port);
-        kfree(hsi);
-}
-EXPORT_SYMBOL_GPL(hsi_free_controller);
-
-/**
  * hsi_free_msg - Free an HSI message
  * @msg: Pointer to the HSI message
  *
@@ -414,37 +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
@@ -458,22 +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 4b178067f405..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);
 
@@ -270,13 +273,13 @@ struct hsi_controller {
         struct module           *owner;
         unsigned int            id;
         unsigned int            num_ports;
-        struct hsi_port         *port;
+        struct hsi_port         **port;
 };
 
 #define to_hsi_controller(dev) container_of(dev, struct hsi_controller, device)
 
 struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags);
-void hsi_free_controller(struct hsi_controller *hsi);
+void hsi_put_controller(struct hsi_controller *hsi);
 int hsi_register_controller(struct hsi_controller *hsi);
 void hsi_unregister_controller(struct hsi_controller *hsi);
 
@@ -294,7 +297,7 @@ static inline void *hsi_controller_drvdata(struct hsi_controller *hsi)
 static inline struct hsi_port *hsi_find_port_num(struct hsi_controller *hsi,
                                                         unsigned int num)
 {
-        return (num < hsi->num_ports) ? &hsi->port[num] : NULL;
+        return (num < hsi->num_ports) ? hsi->port[num] : NULL;
 }
 
 /*