[PATCH] USB ATM: new usbatm core

Rework the core usbatm code: minidrivers (i.e. drivers for particular
modems) now register themselves with the usbatm core, supplying methods
for binding/unbinding etc.  The design was inspired by usb-serial and
usbnet.  At the same time, more common code from the speedtch and
cxacru (patch 3/5) drivers was generalized and moved into the core.  The
transmission and reception parts have been unified and simplified.  Since
this is a major change and I don't like underscores in file names,
usb_atm.[ch] has been renamed usbatm.[ch].

Many thanks to Roman Kagan, who did a lot of the coding.
Signed-off-by: NDuncan Sands <baldrick@free.fr>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/atm/usb_atm.h → drivers/usb/atm/usbatm.h

 /******************************************************************************
- *  usb_atm.h - Generic USB xDSL driver core
+ *  usbatm.h - Generic USB xDSL driver core
  *
  *  Copyright (C) 2001, Alcatel
  *  Copyright (C) 2003, Duncan Sands, SolNegro, Josep Comas
@@ -21,12 +21,10 @@
  *
  ******************************************************************************/
 
+#ifndef	_USBATM_H_
+#define	_USBATM_H_
+
 #include <linux/config.h>
-#include <linux/list.h>
-#include <linux/kref.h>
-#include <linux/atm.h>
-#include <linux/atmdev.h>
-#include <asm/semaphore.h>
 
 /*
 #define DEBUG
@@ -37,140 +35,149 @@
 #	define DEBUG
 #endif
 
+#include <asm/semaphore.h>
+#include <linux/atm.h>
+#include <linux/atmdev.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/kref.h>
+#include <linux/list.h>
+#include <linux/stringify.h>
 #include <linux/usb.h>
 
 #ifdef DEBUG
 #define UDSL_ASSERT(x)	BUG_ON(!(x))
 #else
-#define UDSL_ASSERT(x)	do { if (!(x)) warn("failed assertion '" #x "' at line %d", __LINE__); } while(0)
+#define UDSL_ASSERT(x)	do { if (!(x)) warn("failed assertion '%s' at line %d", __stringify(x), __LINE__); } while(0)
 #endif
 
-#define UDSL_MAX_RCV_URBS		4
-#define UDSL_MAX_SND_URBS		4
-#define UDSL_MAX_RCV_BUFS		8
-#define UDSL_MAX_SND_BUFS		8
-#define UDSL_MAX_RCV_BUF_SIZE		1024	/* ATM cells */
-#define UDSL_MAX_SND_BUF_SIZE		1024	/* ATM cells */
-#define UDSL_DEFAULT_RCV_URBS		2
-#define UDSL_DEFAULT_SND_URBS		2
-#define UDSL_DEFAULT_RCV_BUFS		4
-#define UDSL_DEFAULT_SND_BUFS		4
-#define UDSL_DEFAULT_RCV_BUF_SIZE	64	/* ATM cells */
-#define UDSL_DEFAULT_SND_BUF_SIZE	64	/* ATM cells */
-
-#define ATM_CELL_HEADER			(ATM_CELL_SIZE - ATM_CELL_PAYLOAD)
-#define UDSL_NUM_CELLS(x)		(((x) + ATM_AAL5_TRAILER + ATM_CELL_PAYLOAD - 1) / ATM_CELL_PAYLOAD)
-
-/* receive */
-
-struct udsl_receive_buffer {
-	struct list_head list;
-	unsigned char *base;
-	unsigned int filled_cells;
-};
+#define usb_err(instance, format, arg...)	\
+	dev_err(&(instance)->usb_intf->dev , format , ## arg)
+#define usb_info(instance, format, arg...)	\
+	dev_info(&(instance)->usb_intf->dev , format , ## arg)
+#define usb_warn(instance, format, arg...)	\
+	dev_warn(&(instance)->usb_intf->dev , format , ## arg)
+#define usb_dbg(instance, format, arg...)	\
+	dev_dbg(&(instance)->usb_intf->dev , format , ## arg)
+
+/* FIXME: move to dev_* once ATM is driver model aware */
+#define atm_printk(level, instance, format, arg...)	\
+	printk(level "ATM dev %d: " format , (instance)->atm_dev->number, ## arg)
+
+#define atm_err(instance, format, arg...)	\
+	atm_printk(KERN_ERR, instance , format , ## arg)
+#define atm_info(instance, format, arg...)	\
+	atm_printk(KERN_INFO, instance , format , ## arg)
+#define atm_warn(instance, format, arg...)	\
+	atm_printk(KERN_WARNING, instance , format , ## arg)
+#ifdef DEBUG
+#define atm_dbg(instance, format, arg...)	\
+	atm_printk(KERN_DEBUG, instance , format , ## arg)
+#else
+#define atm_dbg(instance, format, arg...)	\
+	do {} while (0)
+#endif
 
-struct udsl_receiver {
-	struct list_head list;
-	struct udsl_receive_buffer *buffer;
-	struct urb *urb;
-	struct udsl_instance_data *instance;
-};
 
-struct udsl_vcc_data {
-	/* vpi/vci lookup */
-	struct list_head list;
-	short vpi;
-	int vci;
-	struct atm_vcc *vcc;
+/* mini driver */
 
-	/* raw cell reassembly */
-	struct sk_buff *sarb;
-};
+struct usbatm_data;
 
-/* send */
+/*
+*  Assuming all methods exist and succeed, they are called in this order:
+*
+*  	bind, heavy_init, atm_start, ..., atm_stop, unbind
+*/
 
-struct udsl_send_buffer {
-	struct list_head list;
-	unsigned char *base;
-	unsigned char *free_start;
-	unsigned int free_cells;
-};
+struct usbatm_driver {
+	struct module *owner;
 
-struct udsl_sender {
-	struct list_head list;
-	struct udsl_send_buffer *buffer;
-	struct urb *urb;
-	struct udsl_instance_data *instance;
-};
+	const char *driver_name;
+
+	/*
+	*  init device ... can sleep, or cause probe() failure.  Drivers with a heavy_init
+	*  method can avoid having it called by setting need_heavy_init to zero.
+	*/
+        int (*bind) (struct usbatm_data *, struct usb_interface *,
+		     const struct usb_device_id *id, int *need_heavy_init);
+
+	/* additional device initialization that is too slow to be done in probe() */
+        int (*heavy_init) (struct usbatm_data *, struct usb_interface *);
+
+	/* cleanup device ... can sleep, but can't fail */
+        void (*unbind) (struct usbatm_data *, struct usb_interface *);
 
-struct udsl_control {
-	struct atm_skb_data atm_data;
-	unsigned int num_cells;
-	unsigned int num_entire;
-	unsigned int pdu_padding;
-	unsigned char aal5_trailer[ATM_AAL5_TRAILER];
+	/* init ATM device ... can sleep, or cause ATM initialization failure */
+	int (*atm_start) (struct usbatm_data *, struct atm_dev *);
+
+	/* cleanup ATM device ... can sleep, but can't fail */
+	void (*atm_stop) (struct usbatm_data *, struct atm_dev *);
+
+        int in;		/* rx endpoint */
+        int out;	/* tx endpoint */
+
+	unsigned rx_padding;
+	unsigned tx_padding;
 };
 
-#define UDSL_SKB(x)		((struct udsl_control *)(x)->cb)
+extern int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id,
+		struct usbatm_driver *driver);
+extern void usbatm_usb_disconnect(struct usb_interface *intf);
 
-/* main driver data */
 
-enum udsl_status {
-	UDSL_NO_FIRMWARE,
-	UDSL_LOADING_FIRMWARE,
-	UDSL_LOADED_FIRMWARE
+struct usbatm_channel {
+	int endpoint;			/* usb pipe */
+	unsigned int stride;		/* ATM cell size + padding */
+	unsigned int buf_size;		/* urb buffer size */
+	spinlock_t lock;
+	struct list_head list;
+	struct tasklet_struct tasklet;
+	struct timer_list delay;
+	struct usbatm_data *usbatm;
 };
 
-struct udsl_instance_data {
-	struct kref refcount;
-	struct semaphore serialize;
+/* main driver data */
+
+struct usbatm_data {
+	/******************
+	*  public fields  *
+        ******************/
 
-	/* USB device part */
+	/* mini driver */
+	struct usbatm_driver *driver;
+	void *driver_data;
+	char driver_name[16];
+
+	/* USB device */
 	struct usb_device *usb_dev;
+	struct usb_interface *usb_intf;
 	char description[64];
-	int data_endpoint;
-	int snd_padding;
-	int rcv_padding;
-	const char *driver_name;
 
-	/* ATM device part */
+	/* ATM device */
 	struct atm_dev *atm_dev;
-	struct list_head vcc_list;
 
-	/* firmware */
-	int (*firmware_wait) (struct udsl_instance_data *);
-	enum udsl_status status;
-	wait_queue_head_t firmware_waiters;
+	/********************************
+	*  private fields - do not use  *
+        ********************************/
 
-	/* receive */
-	struct udsl_receiver receivers[UDSL_MAX_RCV_URBS];
-	struct udsl_receive_buffer receive_buffers[UDSL_MAX_RCV_BUFS];
+	struct kref refcount;
+	struct semaphore serialize;
 
-	spinlock_t receive_lock;
-	struct list_head spare_receivers;
-	struct list_head filled_receive_buffers;
+	/* heavy init */
+	int thread_pid;
+	struct completion thread_started;
+	struct completion thread_exited;
 
-	struct tasklet_struct receive_tasklet;
-	struct list_head spare_receive_buffers;
+	/* ATM device */
+	struct list_head vcc_list;
 
-	/* send */
-	struct udsl_sender senders[UDSL_MAX_SND_URBS];
-	struct udsl_send_buffer send_buffers[UDSL_MAX_SND_BUFS];
+	struct usbatm_channel rx_channel;
+	struct usbatm_channel tx_channel;
 
 	struct sk_buff_head sndqueue;
-
-	spinlock_t send_lock;
-	struct list_head spare_senders;
-	struct list_head spare_send_buffers;
-
-	struct tasklet_struct send_tasklet;
 	struct sk_buff *current_skb;			/* being emptied */
-	struct udsl_send_buffer *current_buffer;	/* being filled */
-	struct list_head filled_send_buffers;
+
+	struct urb *urbs[0];
 };
 
-extern int udsl_instance_setup(struct usb_device *dev,
-			       struct udsl_instance_data *instance);
-extern void udsl_instance_disconnect(struct udsl_instance_data *instance);
-extern void udsl_get_instance(struct udsl_instance_data *instance);
-extern void udsl_put_instance(struct udsl_instance_data *instance);
+#endif	/* _USBATM_H_ */