USB: kl5usb105: reimplement using generic framework

Kill custom read and write implementations (static per-port,
singleton(!) urb pool).

Also remove changelog header (can be retrieved through git).

Read processing and write-buffer handling tested using a cp210x device
in a loopback setup.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 47 insertions, 333 deletions

diff --git a/drivers/usb/serial/kl5kusb105.c b/drivers/usb/serial/kl5kusb105.c
index ad168255cc04..cdbe8bf7f674 100644
--- a/drivers/usb/serial/kl5kusb105.c
+++ b/drivers/usb/serial/kl5kusb105.c
@@ -1,6 +1,7 @@
 /*
  * KLSI KL5KUSB105 chip RS232 converter driver
  *
+ *   Copyright (C) 2010 Johan Hovold <jhovold@gmail.com>
  *   Copyright (C) 2001 Utz-Uwe Haus <haus@uuhaus.de>
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -34,17 +35,6 @@
  *      implement handshaking or decide that we do not support it
  */
 
-/* History:
- *   0.3a - implemented pools of write URBs
- *   0.3  - alpha version for public testing
- *   0.2  - TIOCMGET works, so autopilot(1) can be used!
- *   0.1  - can be used to do pilot-xfer -p /dev/ttyUSB0 -l
- *
- *   The driver skeleton is mainly based on mct_u232.c and various other
- *   pieces of code shamelessly copied from the drivers/usb/serial/ directory.
- */
-
-
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/init.h>
@@ -64,8 +54,8 @@ static int debug;
 /*
  * Version Information
  */
-#define DRIVER_VERSION "v0.3a"
-#define DRIVER_AUTHOR "Utz-Uwe Haus <haus@uuhaus.de>"
+#define DRIVER_VERSION "v0.4"
+#define DRIVER_AUTHOR "Utz-Uwe Haus <haus@uuhaus.de>, Johan Hovold <jhovold@gmail.com>"
 #define DRIVER_DESC "KLSI KL5KUSB105 chipset USB->Serial Converter driver"
 
 
@@ -73,23 +63,17 @@ static int debug;
  * Function prototypes
  */
 static int  klsi_105_startup(struct usb_serial *serial);
-static void klsi_105_disconnect(struct usb_serial *serial);
 static void klsi_105_release(struct usb_serial *serial);
 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port);
 static void klsi_105_close(struct usb_serial_port *port);
-static int  klsi_105_write(struct tty_struct *tty,
-        struct usb_serial_port *port, const unsigned char *buf, int count);
-static void klsi_105_write_bulk_callback(struct urb *urb);
-static int  klsi_105_chars_in_buffer(struct tty_struct *tty);
-static int  klsi_105_write_room(struct tty_struct *tty);
-static void klsi_105_read_bulk_callback(struct urb *urb);
 static void klsi_105_set_termios(struct tty_struct *tty,
                         struct usb_serial_port *port, struct ktermios *old);
-static void klsi_105_throttle(struct tty_struct *tty);
-static void klsi_105_unthrottle(struct tty_struct *tty);
 static int  klsi_105_tiocmget(struct tty_struct *tty, struct file *file);
 static int  klsi_105_tiocmset(struct tty_struct *tty, struct file *file,
                         unsigned int set, unsigned int clear);
+static void klsi_105_process_read_urb(struct urb *urb);
+static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
+                                                void *dest, size_t size);
 
 /*
  * All of the device info needed for the KLSI converters.
@@ -119,22 +103,19 @@ static struct usb_serial_driver kl5kusb105d_device = {
         .usb_driver =           &kl5kusb105d_driver,
         .id_table =             id_table,
         .num_ports =            1,
+        .bulk_out_size =        64,
         .open =                 klsi_105_open,
         .close =                klsi_105_close,
-        .write =                klsi_105_write,
-        .write_bulk_callback =  klsi_105_write_bulk_callback,
-        .chars_in_buffer =      klsi_105_chars_in_buffer,
-        .write_room =           klsi_105_write_room,
-        .read_bulk_callback =   klsi_105_read_bulk_callback,
         .set_termios =          klsi_105_set_termios,
         /*.break_ctl =          klsi_105_break_ctl,*/
         .tiocmget =             klsi_105_tiocmget,
         .tiocmset =             klsi_105_tiocmset,
         .attach =               klsi_105_startup,
-        .disconnect =           klsi_105_disconnect,
         .release =              klsi_105_release,
-        .throttle =             klsi_105_throttle,
-        .unthrottle =           klsi_105_unthrottle,
+        .throttle =             usb_serial_generic_throttle,
+        .unthrottle =           usb_serial_generic_unthrottle,
+        .process_read_urb =     klsi_105_process_read_urb,
+        .prepare_write_buffer = klsi_105_prepare_write_buffer,
 };
 
 struct klsi_105_port_settings {
@@ -145,18 +126,11 @@ struct klsi_105_port_settings {
         __u8    unknown2;
 } __attribute__ ((packed));
 
-/* we implement a pool of NUM_URBS urbs per usb_serial */
-#define NUM_URBS                        1
-#define URB_TRANSFER_BUFFER_SIZE        64
 struct klsi_105_private {
         struct klsi_105_port_settings   cfg;
         struct ktermios                 termios;
         unsigned long                   line_state; /* modem line settings */
-        /* write pool */
-        struct urb                      *write_urb_pool[NUM_URBS];
         spinlock_t                      lock;
-        unsigned long                   bytes_in;
-        unsigned long                   bytes_out;
 };
 
 
@@ -259,7 +233,7 @@ static int klsi_105_get_line_state(struct usb_serial_port *port,
 static int klsi_105_startup(struct usb_serial *serial)
 {
         struct klsi_105_private *priv;
-        int i, j;
+        int i;
 
         /* check if we support the product id (see keyspan.c)
          * FIXME
@@ -283,29 +257,9 @@ static int klsi_105_startup(struct usb_serial *serial)
 
                 priv->line_state    = 0;
 
-                priv->bytes_in      = 0;
-                priv->bytes_out     = 0;
                 usb_set_serial_port_data(serial->port[i], priv);
 
                 spin_lock_init(&priv->lock);
-                for (j = 0; j < NUM_URBS; j++) {
-                        struct urb *urb = usb_alloc_urb(0, GFP_KERNEL);
-
-                        priv->write_urb_pool[j] = urb;
-                        if (urb == NULL) {
-                                dev_err(&serial->dev->dev, "No more urbs???\n");
-                                goto err_cleanup;
-                        }
-
-                        urb->transfer_buffer =
-                                kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_KERNEL);
-                        if (!urb->transfer_buffer) {
-                                dev_err(&serial->dev->dev,
-                                        "%s - out of memory for urb buffers.\n",
-                                        __func__);
-                                goto err_cleanup;
-                        }
-                }
 
                 /* priv->termios is left uninitalized until port opening */
                 init_waitqueue_head(&serial->port[i]->write_wait);
@@ -316,56 +270,20 @@ static int klsi_105_startup(struct usb_serial *serial)
 err_cleanup:
         for (; i >= 0; i--) {
                 priv = usb_get_serial_port_data(serial->port[i]);
-                for (j = 0; j < NUM_URBS; j++) {
-                        if (priv->write_urb_pool[j]) {
-                                kfree(priv->write_urb_pool[j]->transfer_buffer);
-                                usb_free_urb(priv->write_urb_pool[j]);
-                        }
-                }
                 kfree(priv);
                 usb_set_serial_port_data(serial->port[i], NULL);
         }
         return -ENOMEM;
 }
 
-static void klsi_105_disconnect(struct usb_serial *serial)
-{
-        int i;
-
-        dbg("%s", __func__);
-
-        /* stop reads and writes on all ports */
-        for (i = 0; i < serial->num_ports; ++i) {
-                struct klsi_105_private *priv =
-                                usb_get_serial_port_data(serial->port[i]);
-
-                if (priv) {
-                        /* kill our write urb pool */
-                        int j;
-                        struct urb **write_urbs = priv->write_urb_pool;
-
-                        for (j = 0; j < NUM_URBS; j++) {
-                                if (write_urbs[j]) {
-                                        usb_kill_urb(write_urbs[j]);
-                                        usb_free_urb(write_urbs[j]);
-                                }
-                        }
-                }
-        }
-}
-
 static void klsi_105_release(struct usb_serial *serial)
 {
         int i;
 
         dbg("%s", __func__);
 
-        for (i = 0; i < serial->num_ports; ++i) {
-                struct klsi_105_private *priv =
-                                usb_get_serial_port_data(serial->port[i]);
-
-                kfree(priv);
-        }
+        for (i = 0; i < serial->num_ports; ++i)
+                kfree(usb_get_serial_port_data(serial->port[i]));
 }
 
 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
@@ -416,18 +334,8 @@ static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port)
         spin_unlock_irqrestore(&priv->lock, flags);
 
         /* READ_ON and urb submission */
-        usb_fill_bulk_urb(port->read_urb, port->serial->dev,
-                      usb_rcvbulkpipe(port->serial->dev,
-                                      port->bulk_in_endpointAddress),
-                      port->read_urb->transfer_buffer,
-                      port->read_urb->transfer_buffer_length,
-                      klsi_105_read_bulk_callback,
-                      port);
-
-        rc = usb_submit_urb(port->read_urb, GFP_KERNEL);
+        rc = usb_serial_generic_open(tty, port);
         if (rc) {
-                dev_err(&port->dev, "%s - failed submitting read urb, "
-                        "error %d\n", __func__, rc);
                 retval = rc;
                 goto exit;
         }
@@ -464,7 +372,6 @@ exit:
 
 static void klsi_105_close(struct usb_serial_port *port)
 {
-        struct klsi_105_private *priv = usb_get_serial_port_data(port);
         int rc;
 
         dbg("%s port %d", __func__, port->number);
@@ -487,232 +394,61 @@ static void klsi_105_close(struct usb_serial_port *port)
         mutex_unlock(&port->serial->disc_mutex);
 
         /* shutdown our bulk reads and writes */
-        usb_kill_urb(port->write_urb);
-        usb_kill_urb(port->read_urb);
-        /* unlink our write pool */
-        /* FIXME */
+        usb_serial_generic_close(port);
+
         /* wgg - do I need this? I think so. */
         usb_kill_urb(port->interrupt_in_urb);
-        dev_info(&port->serial->dev->dev,
-                 "port stats: %ld bytes in, %ld bytes out\n",
-                 priv->bytes_in, priv->bytes_out);
 }
 
 /* We need to write a complete 64-byte data block and encode the
  * number actually sent in the first double-byte, LSB-order. That
  * leaves at most 62 bytes of payload.
  */
-#define KLSI_105_DATA_OFFSET    2   /* in the bulk urb data block */
-
-static int klsi_105_write(struct tty_struct *tty,
-        struct usb_serial_port *port, const unsigned char *buf, int count)
-{
-        struct klsi_105_private *priv = usb_get_serial_port_data(port);
-        int result, size;
-        int bytes_sent = 0;
-
-        dbg("%s - port %d", __func__, port->number);
-
-        while (count > 0) {
-                /* try to find a free urb (write 0 bytes if none) */
-                struct urb *urb = NULL;
-                unsigned long flags;
-                int i;
-                /* since the pool is per-port we might not need
-                   the spin lock !? */
-                spin_lock_irqsave(&priv->lock, flags);
-                for (i = 0; i < NUM_URBS; i++) {
-                        if (priv->write_urb_pool[i]->status != -EINPROGRESS) {
-                                urb = priv->write_urb_pool[i];
-                                dbg("%s - using pool URB %d", __func__, i);
-                                break;
-                        }
-                }
-                spin_unlock_irqrestore(&priv->lock, flags);
-
-                if (urb == NULL) {
-                        dbg("%s - no more free urbs", __func__);
-                        goto exit;
-                }
-
-                if (urb->transfer_buffer == NULL) {
-                        urb->transfer_buffer =
-                                kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_ATOMIC);
-                        if (urb->transfer_buffer == NULL) {
-                                dev_err(&port->dev,
-                                        "%s - no more kernel memory...\n",
-                                        __func__);
-                                goto exit;
-                        }
-                }
-
-                size = min(count, port->bulk_out_size - KLSI_105_DATA_OFFSET);
-                size = min(size, URB_TRANSFER_BUFFER_SIZE -
-                                                        KLSI_105_DATA_OFFSET);
-
-                memcpy(urb->transfer_buffer + KLSI_105_DATA_OFFSET, buf, size);
-
-                /* write payload size into transfer buffer */
-                ((__u8 *)urb->transfer_buffer)[0] = (__u8) (size & 0xFF);
-                ((__u8 *)urb->transfer_buffer)[1] = (__u8) ((size & 0xFF00)>>8);
-
-                /* set up our urb */
-                usb_fill_bulk_urb(urb, port->serial->dev,
-                              usb_sndbulkpipe(port->serial->dev,
-                                              port->bulk_out_endpointAddress),
-                              urb->transfer_buffer,
-                              URB_TRANSFER_BUFFER_SIZE,
-                              klsi_105_write_bulk_callback,
-                              port);
-
-                /* send the data out the bulk port */
-                result = usb_submit_urb(urb, GFP_ATOMIC);
-                if (result) {
-                        dev_err(&port->dev,
-                                "%s - failed submitting write urb, error %d\n",
-                                __func__, result);
-                        goto exit;
-                }
-                buf += size;
-                bytes_sent += size;
-                count -= size;
-        }
-exit:
-        /* lockless, but it's for debug info only... */
-        priv->bytes_out += bytes_sent;
-
-        return bytes_sent;      /* that's how much we wrote */
-}
-
-static void klsi_105_write_bulk_callback(struct urb *urb)
+#define KLSI_HDR_LEN            2
+static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
+                                                void *dest, size_t size)
 {
-        struct usb_serial_port *port = urb->context;
-        int status = urb->status;
-
-        dbg("%s - port %d", __func__, port->number);
+        unsigned char *buf = dest;
+        int count;
 
-        if (status) {
-                dbg("%s - nonzero write bulk status received: %d", __func__,
-                    status);
-                return;
-        }
+        count = kfifo_out_locked(&port->write_fifo, buf + KLSI_HDR_LEN, size,
+                                                                &port->lock);
+        put_unaligned_le16(count, buf);
 
-        usb_serial_port_softint(port);
+        return count + KLSI_HDR_LEN;
 }
 
-/* return number of characters currently in the writing process */
-static int klsi_105_chars_in_buffer(struct tty_struct *tty)
-{
-        struct usb_serial_port *port = tty->driver_data;
-        int chars = 0;
-        int i;
-        unsigned long flags;
-        struct klsi_105_private *priv = usb_get_serial_port_data(port);
-
-        spin_lock_irqsave(&priv->lock, flags);
-
-        for (i = 0; i < NUM_URBS; ++i) {
-                if (priv->write_urb_pool[i]->status == -EINPROGRESS)
-                        chars += URB_TRANSFER_BUFFER_SIZE;
-        }
-
-        spin_unlock_irqrestore(&priv->lock, flags);
-
-        dbg("%s - returns %d", __func__, chars);
-        return chars;
-}
-
-static int klsi_105_write_room(struct tty_struct *tty)
-{
-        struct usb_serial_port *port = tty->driver_data;
-        unsigned long flags;
-        int i;
-        int room = 0;
-        struct klsi_105_private *priv = usb_get_serial_port_data(port);
-
-        spin_lock_irqsave(&priv->lock, flags);
-        for (i = 0; i < NUM_URBS; ++i) {
-                if (priv->write_urb_pool[i]->status != -EINPROGRESS)
-                        room += URB_TRANSFER_BUFFER_SIZE;
-        }
-
-        spin_unlock_irqrestore(&priv->lock, flags);
-
-        dbg("%s - returns %d", __func__, room);
-        return room;
-}
-
-static void klsi_105_read_bulk_callback(struct urb *urb)
+/* The data received is preceded by a length double-byte in LSB-first order.
+ */
+static void klsi_105_process_read_urb(struct urb *urb)
 {
         struct usb_serial_port *port = urb->context;
-        struct klsi_105_private *priv = usb_get_serial_port_data(port);
-        struct tty_struct *tty;
         unsigned char *data = urb->transfer_buffer;
-        int rc;
-        int status = urb->status;
+        struct tty_struct *tty;
+        unsigned len;
 
-        dbg("%s - port %d", __func__, port->number);
+        /* empty urbs seem to happen, we ignore them */
+        if (!urb->actual_length)
+                return;
 
-        /* The urb might have been killed. */
-        if (status) {
-                dbg("%s - nonzero read bulk status received: %d", __func__,
-                    status);
+        if (urb->actual_length <= KLSI_HDR_LEN) {
+                dbg("%s - malformed packet", __func__);
                 return;
         }
 
-        /* The data received is again preceded by a length double-byte in LSB-
-         * first order (see klsi_105_write() )
-         */
-        if (urb->actual_length == 0) {
-                /* empty urbs seem to happen, we ignore them */
-                /* dbg("%s - emtpy URB", __func__); */
-               ;
-        } else if (urb->actual_length <= 2) {
-                dbg("%s - size %d URB not understood", __func__,
-                    urb->actual_length);
-                usb_serial_debug_data(debug, &port->dev, __func__,
-                                      urb->actual_length, data);
-        } else {
-                int bytes_sent = ((__u8 *) data)[0] +
-                                 ((unsigned int) ((__u8 *) data)[1] << 8);
-                tty = tty_port_tty_get(&port->port);
-                /* we should immediately resubmit the URB, before attempting
-                 * to pass the data on to the tty layer. But that needs locking
-                 * against re-entry an then mixed-up data because of
-                 * intermixed tty_flip_buffer_push()s
-                 * FIXME
-                 */
-                usb_serial_debug_data(debug, &port->dev, __func__,
-                                      urb->actual_length, data);
-
-                if (bytes_sent + 2 > urb->actual_length) {
-                        dbg("%s - trying to read more data than available"
-                            " (%d vs. %d)", __func__,
-                            bytes_sent+2, urb->actual_length);
-                        /* cap at implied limit */
-                        bytes_sent = urb->actual_length - 2;
-                }
-
-                tty_insert_flip_string(tty, data + 2, bytes_sent);
-                tty_flip_buffer_push(tty);
-                tty_kref_put(tty);
+        tty = tty_port_tty_get(&port->port);
+        if (!tty)
+                return;
 
-                /* again lockless, but debug info only */
-                priv->bytes_in += bytes_sent;
+        len = get_unaligned_le16(data);
+        if (len > urb->actual_length - KLSI_HDR_LEN) {
+                dbg("%s - packet length mismatch", __func__);
+                len = urb->actual_length - KLSI_HDR_LEN;
         }
-        /* Continue trying to always read  */
-        usb_fill_bulk_urb(port->read_urb, port->serial->dev,
-                      usb_rcvbulkpipe(port->serial->dev,
-                                      port->bulk_in_endpointAddress),
-                      port->read_urb->transfer_buffer,
-                      port->read_urb->transfer_buffer_length,
-                      klsi_105_read_bulk_callback,
-                      port);
-        rc = usb_submit_urb(port->read_urb, GFP_ATOMIC);
-        if (rc)
-                dev_err(&port->dev,
-                        "%s - failed resubmitting read urb, error %d\n",
-                        __func__, rc);
+
+        tty_insert_flip_string(tty, data + KLSI_HDR_LEN, len);
+        tty_flip_buffer_push(tty);
+        tty_kref_put(tty);
 }
 
 static void klsi_105_set_termios(struct tty_struct *tty,
@@ -954,28 +690,6 @@ static int klsi_105_tiocmset(struct tty_struct *tty, struct file *file,
         return retval;
 }
 
-static void klsi_105_throttle(struct tty_struct *tty)
-{
-        struct usb_serial_port *port = tty->driver_data;
-        dbg("%s - port %d", __func__, port->number);
-        usb_kill_urb(port->read_urb);
-}
-
-static void klsi_105_unthrottle(struct tty_struct *tty)
-{
-        struct usb_serial_port *port = tty->driver_data;
-        int result;
-
-        dbg("%s - port %d", __func__, port->number);
-
-        port->read_urb->dev = port->serial->dev;
-        result = usb_submit_urb(port->read_urb, GFP_KERNEL);
-        if (result)
-                dev_err(&port->dev,
-                        "%s - failed submitting read urb, error %d\n",
-                        __func__, result);
-}
-
 
 static int __init klsi_105_init(void)
 {