Merge tag 'hsi_fixes_for_3.4' of git://gitorious.org/kernel-hsi/kernel-hsi

Pull HSI fixes and ABI documentation from Carlos Chinea

* tag 'hsi_fixes_for_3.4' of git://gitorious.org/kernel-hsi/kernel-hsi:
  HSI: Add HSI ABI documentation
  HSI: hsi_char: Remove max_data_size from sysfs
  HSI: hsi: Rework hsi_event interface
  HSI: hsi: Remove controllers and ports from the bus
  HSI: hsi: Fix error path cleanup on client registration
  HSI: hsi: Rework hsi_controller release

Documentation/ABI/testing/sysfs-bus-hsi

+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>

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,

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;
 }
@@ -222,6 +195,29 @@ static inline int hsi_dummy_cl(struct hsi_client *cl __maybe_unused)
 	return 0;
 }
 
+/**
+ * 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
@@ -232,54 +228,51 @@ 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);
 

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;
 }
 
 /*