[PATCH] Airprime driver improvements to allow full speed EvDO transfers

[Andy Gay <andy@andynet.net>]

Adapted from an earlier patch by Greg KH <gregkh@suse.de>.
That patch added multiple read urbs and larger transfer buffers to allow
data transfers at full EvDO speed.

This version includes additional device IDs and fixes a memory leak in
the transfer buffer allocation.

Some (maybe all?) of the supported devices present multiple bulk endpoints,
the additional EPs can be used for control and status functions.
This version allocates 3 EPs by default, that can be changed using
the 'endpoints' module parameter.

Tested with Sierra Wireless EM5625 and MC5720 embedded modules.

Device ID (0x0c88, 0x17da) for the Kyocera Wireless KPC650/Passport
was added but is not yet tested.

Signed-off-by: Andy Gay <andy@andynet.net>

---
commit 3d1346863aac4b3c016acb409a3b9e6651af8f7a
tree f4359718b8550ce0d95b57ba1b5b0d902bf2ada8
parent 501b7c77de3e90519e95fd99e923bf9a29cd120d
author andy <andy@tahini.andynet.net> Fri, 30 Jun 2006 01:27:13 -0400
committer andy <andy@tahini.andynet.net> Fri, 30 Jun 2006 01:27:13 -0400

 drivers/usb/serial/airprime.c |  227 ++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 222 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/serial/airprime.c b/drivers/usb/serial/airprime.c
index 94b9ba0..5a18f77 100644
--- a/drivers/usb/serial/airprime.c
+++ b/drivers/usb/serial/airprime.c
@@ -1,7 +1,7 @@
 /*
  * AirPrime CDMA Wireless Serial USB driver
  *
- * Copyright (C) 2005 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (C) 2005-2006 Greg Kroah-Hartman <gregkh@suse.de>
  *
  *	This program is free software; you can redistribute it and/or
  *	modify it under the terms of the GNU General Public License version
@@ -11,26 +11,232 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/tty.h>
+#include <linux/tty_flip.h>
 #include <linux/module.h>
 #include <linux/usb.h>
 #include "usb-serial.h"
 
 static struct usb_device_id id_table [] = {
 	{ USB_DEVICE(0x0c88, 0x17da) }, /* Kyocera Wireless KPC650/Passport */
-	{ USB_DEVICE(0xf3d, 0x0112) },  /* AirPrime CDMA Wireless PC Card */
+	{ USB_DEVICE(0x0f3d, 0x0112) },	/* AirPrime CDMA Wireless PC Card */
 	{ USB_DEVICE(0x1410, 0x1110) }, /* Novatel Wireless Merlin CDMA */
+	{ USB_DEVICE(0x1199, 0x0017) }, /* Sierra Wireless EM5625 */
+	{ USB_DEVICE(0x1199, 0x0018) }, /* Sierra Wireless MC5720 */
 	{ USB_DEVICE(0x1199, 0x0112) }, /* Sierra Wireless Aircard 580 */
-	{ USB_DEVICE(0x1199, 0x0218) }, /* Sierra Wireless MC5720 */
 	{ },
 };
 MODULE_DEVICE_TABLE(usb, id_table);
+#define URB_TRANSFER_BUFFER_SIZE	4096
+#define NUM_READ_URBS			4
+#define NUM_WRITE_URBS			4
+#define NUM_BULK_EPS			3
+#define MAX_BULK_EPS			6
+
+/* if overridden by the user, then use their value for the size of the
+ * read and write urbs, and the number of endpoints */
+static int buffer_size = URB_TRANSFER_BUFFER_SIZE;
+static int endpoints = NUM_BULK_EPS;
+static int debug;
+struct airprime_private {
+	spinlock_t lock;
+	int outstanding_urbs;
+	int throttled;
+	struct urb *read_urbp[NUM_READ_URBS];
+};
+
+static void airprime_read_bulk_callback(struct urb *urb, struct pt_regs *regs)
+{
+	struct usb_serial_port *port = urb->context;
+	unsigned char *data = urb->transfer_buffer;
+	struct tty_struct *tty;
+	int result;
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	if (urb->status) {
+		dbg("%s - nonzero read bulk status received: %d",
+		    __FUNCTION__, urb->status);
+		/* something happened, so free up the memory for this urb /*
+		if (urb->transfer_buffer) {
+			kfree (urb->transfer_buffer);
+			urb->transfer_buffer = NULL;
+		}
+		return;
+	}
+	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
+
+	tty = port->tty;
+	if (tty && urb->actual_length) {
+		tty_buffer_request_room(tty, urb->actual_length);
+		tty_insert_flip_string(tty, data, urb->actual_length);
+		tty_flip_buffer_push(tty);
+	}
+	/* should this use GFP_KERNEL? */
+	result = usb_submit_urb(urb, GFP_ATOMIC);
+	if (result)
+		dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n",
+			__FUNCTION__, result);
+	return;
+}
+
+static void airprime_write_bulk_callback(struct urb *urb, struct pt_regs *regs)
+{
+	struct usb_serial_port *port = urb->context;
+	struct airprime_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+
+	/* free up the transfer buffer, as usb_free_urb() does not do this */
+	kfree (urb->transfer_buffer);
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	if (urb->status)
+		dbg("%s - nonzero write bulk status received: %d",
+		    __FUNCTION__, urb->status);
+	spin_lock_irqsave(&priv->lock, flags);
+	--priv->outstanding_urbs;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	usb_serial_port_softint(port);
+}
+
+static int airprime_open(struct usb_serial_port *port, struct file *filp)
+{
+	struct airprime_private *priv = usb_get_serial_port_data(port);
+	struct usb_serial *serial = port->serial;
+	struct urb *urb;
+	char *buffer;
+	int i;
+	int result = 0;
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	/* initialize our private data structure if it isn't already created */
+	if (!priv) {
+		priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+		if (!priv)
+			return -ENOMEM;
+		spin_lock_init(&priv->lock);
+		usb_set_serial_port_data(port, priv);
+	}
+	/* TODO handle error conditions better, right now we leak memory */
+	for (i = 0; i < NUM_READ_URBS; ++i) {
+		buffer = kmalloc(buffer_size, GFP_KERNEL);
+		if (!buffer) {
+			dev_err(&port->dev, "%s - out of memory.\n",
+				__FUNCTION__);
+			return -ENOMEM;
+		}
+		urb = usb_alloc_urb(0, GFP_KERNEL);
+		if (!urb) {
+			dev_err(&port->dev, "%s - no more urbs?\n",
+				__FUNCTION__);
+			return -ENOMEM;
+		}
+		usb_fill_bulk_urb(urb, serial->dev,
+				  usb_rcvbulkpipe(serial->dev,
+						  port->bulk_out_endpointAddress),
+				  buffer, buffer_size,
+				  airprime_read_bulk_callback, port);
+		result = usb_submit_urb(urb, GFP_KERNEL);
+		if (result) {
+			dev_err(&port->dev,
+				"%s - failed submitting read urb %d for port %d, error %d\n",
+				__FUNCTION__, i, port->number, result);
+			return result;
+		}
+		/* fun with reference counting, when this urb is finished, the
+		 * host driver will free it up automatically */
+		/* don't do this here, we need the urb to stay around until the close
+		   function can take care of it */
+		//usb_free_urb (urb);
+		/* instead remember this urb so we can kill it when the
+		   port is closed */
+		priv->read_urbp[i] = urb;
+	}
+	return result;
+}
+
+static void airprime_close(struct usb_serial_port *port, struct file * filp)
+{
+	struct airprime_private *priv = usb_get_serial_port_data(port);
+	int i;
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	/* killing the urb will invoke read_bulk_callback() with an error status,
+	   so the transfer buffer will be freed there */
+	for (i = 0; i < NUM_READ_URBS; ++i) {
+		usb_kill_urb (priv->read_urbp[i]);
+		usb_free_urb (priv->read_urbp[i]);
+	}
+
+	/* free up private structure? */
+}
+
+static int airprime_write(struct usb_serial_port *port,
+			  const unsigned char *buf, int count)
+{
+	struct airprime_private *priv = usb_get_serial_port_data(port);
+	struct usb_serial *serial = port->serial;
+	struct urb *urb;
+	unsigned char *buffer;
+	unsigned long flags;
+	int status;
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->outstanding_urbs > NUM_WRITE_URBS) {
+		spin_unlock_irqrestore(&priv->lock, flags);
+		dbg("%s - write limit hit\n", __FUNCTION__);
+		return 0;
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+	buffer = kmalloc(count, GFP_ATOMIC);
+	if (!buffer) {
+		dev_err(&port->dev, "out of memory\n");
+		return -ENOMEM;
+	}
+	urb = usb_alloc_urb(0, GFP_ATOMIC);
+	if (!urb) {
+		dev_err(&port->dev, "no more free urbs\n");
+		kfree (buffer);
+		return -ENOMEM;
+	}
+	memcpy (buffer, buf, count);
+
+	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, buffer);
+
+	usb_fill_bulk_urb(urb, serial->dev,
+			  usb_sndbulkpipe(serial->dev,
+					  port->bulk_out_endpointAddress),
+			  buffer, count,
+			  airprime_write_bulk_callback, port);
+
+	/* send it down the pipe */
+	status = usb_submit_urb(urb, GFP_ATOMIC);
+	if (status) {
+		dev_err(&port->dev,
+			"%s - usb_submit_urb(write bulk) failed with status = %d\n",
+			__FUNCTION__, status);
+		count = status;
+		kfree (buffer);
+	} else {
+		spin_lock_irqsave(&priv->lock, flags);
+		++priv->outstanding_urbs;
+		spin_unlock_irqrestore(&priv->lock, flags);
+	}
+	/* we are done with this urb, so let the host driver
+	 * really free it when it is finished with it */
+	usb_free_urb (urb);
+	return count;
+}
 
 static struct usb_driver airprime_driver = {
 	.name =		"airprime",
 	.probe =	usb_serial_probe,
 	.disconnect =	usb_serial_disconnect,
 	.id_table =	id_table,
-	.no_dynamic_id = 	1,
+	.no_dynamic_id =	1,
 };
 
 static struct usb_serial_driver airprime_device = {
@@ -42,13 +248,17 @@ static struct usb_serial_driver airprime
 	.num_interrupt_in =	NUM_DONT_CARE,
 	.num_bulk_in =		NUM_DONT_CARE,
 	.num_bulk_out =		NUM_DONT_CARE,
-	.num_ports =		1,
+	.open =			airprime_open,
+	.close =		airprime_close,
+	.write =		airprime_write,
 };
 
 static int __init airprime_init(void)
 {
 	int retval;
 
+	airprime_device.num_ports =
+		(endpoints > 0 && endpoints <= MAX_BULK_EPS) ? endpoints : NUM_BULK_EPS;
 	retval = usb_serial_register(&airprime_device);
 	if (retval)
 		return retval;
@@ -67,3 +277,10 @@ static void __exit airprime_exit(void)
 module_init(airprime_init);
 module_exit(airprime_exit);
 MODULE_LICENSE("GPL");
+
+module_param(debug, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug enabled or not");
+module_param(buffer_size, int, 0);
+MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
+module_param(endpoints, int, 0);
+MODULE_PARM_DESC(endpoints, "Number of bulk EPs to configure (default 3)");



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