Re: [PATCH] ftdi_sio patch
From: Vitja Makarov
Date: Wed Jun 07 2006 - 03:20:55 EST
Sorry for my bad indentation and linewraps, I used circular buffer
implementation from ti_usb_3410_5052 that uses kerenl's circ_buf structure.
Signed-off-by: Vitja Makarov <vitja.makarov@xxxxxxxxx>
vitja.
diff -uprN orig/drivers/usb/serial/ftdi_sio.c new/drivers/usb/serial/ftdi_sio.c
--- orig/drivers/usb/serial/ftdi_sio.c 2006-03-28 01:05:57.000000000 +0400
+++ new/drivers/usb/serial/ftdi_sio.c 2006-06-07 10:48:26.000000000 +0400
@@ -258,6 +258,7 @@
#include <asm/uaccess.h>
#include <linux/usb.h>
#include <linux/serial.h>
+#include <linux/circ_buf.h>
#include "usb-serial.h"
#include "ftdi_sio.h"
@@ -517,6 +518,8 @@ static const char *ftdi_chip_name[] = {
/* Constants for read urb and write urb */
#define BUFSZ 512
#define PKTSZ 64
+/* size of write buffer */
+#define SERIAL_BUF_SIZE 1024
/* rx_flags */
#define THROTTLED 0x01
@@ -545,6 +548,11 @@ struct ftdi_private {
int force_baud; /* if non-zero, force the baud rate to this value */
int force_rtscts; /* if non-zero, force RTS-CTS to always be enabled */
+
+ spinlock_t lock; /* private lock */
+
+ struct circ_buf *buf; /* write buffer */
+ int write_urb_in_use; /* write urb in use indicator */
};
/* Used for TIOCMIWAIT */
@@ -562,6 +570,7 @@ static void ftdi_shutdown (struct usb_s
static int ftdi_open (struct usb_serial_port *port, struct file *filp);
static void ftdi_close (struct usb_serial_port *port, struct file *filp);
static int ftdi_write (struct usb_serial_port *port, const unsigned char *buf, int count);
+static void ftdi_send (struct usb_serial_port *port);
static int ftdi_write_room (struct usb_serial_port *port);
static int ftdi_chars_in_buffer (struct usb_serial_port *port);
static void ftdi_write_bulk_callback (struct urb *urb, struct pt_regs *regs);
@@ -575,6 +584,14 @@ static void ftdi_break_ctl (struct usb_
static void ftdi_throttle (struct usb_serial_port *port);
static void ftdi_unthrottle (struct usb_serial_port *port);
+/* circular buffer */
+static struct circ_buf *serial_buf_alloc(void);
+static void serial_buf_free(struct circ_buf *cb);
+static void serial_buf_clear(struct circ_buf *cb);
+static int serial_buf_data_avail(struct circ_buf *cb);
+static int serial_buf_put(struct circ_buf *cb, const char *buf, int count);
+static int serial_buf_get(struct circ_buf *cb, char *buf, int count);
+
static unsigned short int ftdi_232am_baud_base_to_divisor (int baud, int base);
static unsigned short int ftdi_232am_baud_to_divisor (int baud);
static __u32 ftdi_232bm_baud_base_to_divisor (int baud, int base);
@@ -1138,6 +1155,7 @@ static int ftdi_sio_attach (struct usb_s
struct usb_serial_port *port = serial->port[0];
struct ftdi_private *priv;
struct ftdi_sio_quirk *quirk;
+ char *transfer_buffer;
dbg("%s",__FUNCTION__);
@@ -1147,6 +1165,7 @@ static int ftdi_sio_attach (struct usb_s
return -ENOMEM;
}
memset(priv, 0, sizeof(*priv));
+ spin_lock_init(&priv->lock);
spin_lock_init(&priv->rx_lock);
init_waitqueue_head(&priv->delta_msr_wait);
@@ -1167,14 +1186,22 @@ static int ftdi_sio_attach (struct usb_s
}
INIT_WORK(&priv->rx_work, ftdi_process_read, port);
+
+ /* Try to increase the size of write buffer */
+ transfer_buffer = kmalloc(SERIAL_BUF_SIZE, GFP_KERNEL);
+
+ if (transfer_buffer) {
+ port->write_urb->transfer_buffer = transfer_buffer;
+ port->write_urb->transfer_buffer_length = SERIAL_BUF_SIZE;
+ }
/* Free port's existing write urb and transfer buffer. */
- if (port->write_urb) {
- usb_free_urb (port->write_urb);
- port->write_urb = NULL;
+ priv->buf = serial_buf_alloc();
+ if (priv->buf == NULL) {
+ kfree(port->bulk_in_buffer);
+ kfree(priv);
+ return -ENOMEM;
}
- kfree(port->bulk_out_buffer);
- port->bulk_out_buffer = NULL;
usb_set_serial_port_data(serial->port[0], priv);
@@ -1246,6 +1273,7 @@ static void ftdi_shutdown (struct usb_se
*/
if (priv) {
+ serial_buf_free(priv->buf);
usb_set_serial_port_data(port, NULL);
kfree(priv);
}
@@ -1258,7 +1286,7 @@ static int ftdi_open (struct usb_serial
struct usb_device *dev = port->serial->dev;
struct ftdi_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
-
+
int result = 0;
char buf[1]; /* Needed for the usb_control_msg I think */
@@ -1341,132 +1369,139 @@ static void ftdi_close (struct usb_seria
/* cancel any scheduled reading */
cancel_delayed_work(&priv->rx_work);
flush_scheduled_work();
-
+
/* shutdown our bulk read */
if (port->read_urb)
usb_kill_urb(port->read_urb);
+
+ /* shutdown our bulk write */
+ if (port->write_urb)
+ usb_kill_urb(port->write_urb);
} /* ftdi_close */
+static int ftdi_write(struct usb_serial_port *port, const unsigned char *buf, int count)
+{
+ struct ftdi_private *priv = usb_get_serial_port_data(port);
+ unsigned long flags;
+
+ dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);
-
-/* The SIO requires the first byte to have:
- * B0 1
- * B1 0
- * B2..7 length of message excluding byte 0
- *
- * The new devices do not require this byte
- */
-static int ftdi_write (struct usb_serial_port *port,
- const unsigned char *buf, int count)
-{ /* ftdi_write */
+ if (!count)
+ return count;
+
+ spin_lock_irqsave(&priv->lock, flags);
+ count = serial_buf_put(priv->buf, buf, count);
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ ftdi_send(port);
+
+ return count;
+} /* ftdi_write */
+
+
+static void ftdi_send(struct usb_serial_port *port)
+{
+ int count, result;
struct ftdi_private *priv = usb_get_serial_port_data(port);
- struct urb *urb;
- unsigned char *buffer;
+ unsigned long flags;
int data_offset ; /* will be 1 for the SIO and 0 otherwise */
- int status;
- int transfer_size;
- dbg("%s port %d, %d bytes", __FUNCTION__, port->number, count);
+ dbg("%s - port %d", __FUNCTION__, port->number);
- if (count == 0) {
- dbg("write request of 0 bytes");
- return 0;
+ spin_lock_irqsave(&priv->lock, flags);
+
+ if (priv->write_urb_in_use) {
+ spin_unlock_irqrestore(&priv->lock, flags);
+ return;
}
-
+
data_offset = priv->write_offset;
dbg("data_offset set to %d",data_offset);
- /* Determine total transfer size */
- transfer_size = count;
- if (data_offset > 0) {
- /* Original sio needs control bytes too... */
- transfer_size += (data_offset *
- ((count + (PKTSZ - 1 - data_offset)) /
- (PKTSZ - data_offset)));
- }
-
- buffer = kmalloc (transfer_size, GFP_ATOMIC);
- if (!buffer) {
- err("%s ran out of kernel memory for urb ...", __FUNCTION__);
- return -ENOMEM;
- }
- urb = usb_alloc_urb(0, GFP_ATOMIC);
- if (!urb) {
- err("%s - no more free urbs", __FUNCTION__);
- kfree (buffer);
- return -ENOMEM;
+ if (data_offset > 0) {
+ int len = port->bulk_out_size;
+ unsigned char *first_byte = port->write_urb->transfer_buffer;
+
+ count = 0;
+
+ while (serial_buf_data_avail(priv->buf) && len > 1) {
+ int toget = min(len - data_offset, PKTSZ - data_offset);
+ int cnt;
+
+ cnt = serial_buf_get(priv->buf, first_byte + data_offset,
+ toget);
+ *first_byte |= 1 | (cnt << 2);
+ first_byte += cnt + data_offset;
+ len -= cnt + data_offset;
+ count += cnt + data_offset;
+ }
+ } else {
+ count = serial_buf_get(priv->buf, port->write_urb->transfer_buffer,
+ port->bulk_out_size);
}
- /* Copy data */
- if (data_offset > 0) {
- /* Original sio requires control byte at start of each packet. */
- int user_pktsz = PKTSZ - data_offset;
- int todo = count;
- unsigned char *first_byte = buffer;
- const unsigned char *current_position = buf;
-
- while (todo > 0) {
- if (user_pktsz > todo) {
- user_pktsz = todo;
- }
- /* Write the control byte at the front of the packet*/
- *first_byte = 1 | ((user_pktsz) << 2);
- /* Copy data for packet */
- memcpy (first_byte + data_offset,
- current_position, user_pktsz);
- first_byte += user_pktsz + data_offset;
- current_position += user_pktsz;
- todo -= user_pktsz;
- }
- } else {
- /* No control byte required. */
- /* Copy in the data to send */
- memcpy (buffer, buf, count);
+ if (count == 0) {
+ spin_unlock_irqrestore(&priv->lock, flags);
+ return;
}
- usb_serial_debug_data(debug, &port->dev, __FUNCTION__, transfer_size, buffer);
+ priv->write_urb_in_use = 1;
+ spin_unlock_irqrestore(&priv->lock, flags);
- /* fill the buffer and send it */
- usb_fill_bulk_urb(urb, port->serial->dev,
- usb_sndbulkpipe(port->serial->dev, port->bulk_out_endpointAddress),
- buffer, transfer_size,
- ftdi_write_bulk_callback, port);
+ usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, port->write_urb->transfer_buffer);
- status = usb_submit_urb(urb, GFP_ATOMIC);
- if (status) {
- err("%s - failed submitting write urb, error %d", __FUNCTION__, status);
- count = status;
- kfree (buffer);
+ port->write_urb->transfer_buffer_length = count;
+ port->write_urb->dev = port->serial->dev;
+ result = usb_submit_urb (port->write_urb, GFP_ATOMIC);
+ if (result) {
+ dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
+ priv->write_urb_in_use = 0;
+ // TODO: reschedule pl2303_send
}
- /* we are done with this urb, so let the host driver
- * really free it when it is finished with it */
- usb_free_urb (urb);
-
- dbg("%s write returning: %d", __FUNCTION__, count);
- return count;
-} /* ftdi_write */
-
+ schedule_work(&port->work);
+}
-/* This function may get called when the device is closed */
static void ftdi_write_bulk_callback (struct urb *urb, struct pt_regs *regs)
{
- struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
-
- /* free up the transfer buffer, as usb_free_urb() does not do this */
- kfree (urb->transfer_buffer);
+ struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
+ struct ftdi_private *priv = usb_get_serial_port_data(port);
+ int result;
dbg("%s - port %d", __FUNCTION__, port->number);
-
- if (urb->status) {
- dbg("nonzero write bulk status received: %d", urb->status);
+
+ switch (urb->status) {
+ case 0:
+ /* success */
+ break;
+ case -ECONNRESET:
+ case -ENOENT:
+ case -ESHUTDOWN:
+ /* this urb is terminated, clean up */
+ dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
+ priv->write_urb_in_use = 0;
return;
+ default:
+ /* error in the urb, so we have to resubmit it */
+ dbg("%s - Overflow in write", __FUNCTION__);
+ dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
+ port->write_urb->transfer_buffer_length = 1;
+ port->write_urb->dev = port->serial->dev;
+ result = usb_submit_urb (port->write_urb, GFP_ATOMIC);
+ if (result)
+ dev_err(&urb->dev->dev, "%s - failed resubmitting write urb, error %d\n", __FUNCTION__, result);
+ else
+ return;
}
- schedule_work(&port->work);
-} /* ftdi_write_bulk_callback */
+ priv->write_urb_in_use = 0;
+
+ /* send any buffered data */
+ ftdi_send(port);
+}
+
static int ftdi_write_room( struct usb_serial_port *port )
@@ -2078,6 +2113,129 @@ static void ftdi_unthrottle (struct usb_
schedule_work(&priv->rx_work);
}
+/* Circular Buffer Functions, code from ti_usb_3410_5052 used */
+
+/*
+ * serial_buf_alloc
+ *
+ * Allocate a circular buffer and all associated memory.
+ */
+
+static struct circ_buf *serial_buf_alloc(void)
+{
+ struct circ_buf *cb;
+
+ cb = (struct circ_buf *)kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
+ if (cb == NULL)
+ return NULL;
+
+ cb->buf = kmalloc(SERIAL_BUF_SIZE, GFP_KERNEL);
+ if (cb->buf == NULL) {
+ kfree(cb);
+ return NULL;
+ }
+
+ serial_buf_clear(cb);
+
+ return cb;
+}
+
+
+/*
+ * serial_buf_free
+ *
+ * Free the buffer and all associated memory.
+ */
+
+static void serial_buf_free(struct circ_buf *cb)
+{
+ kfree(cb->buf);
+ kfree(cb);
+}
+
+
+/*
+ * serial_buf_clear
+ *
+ * Clear out all data in the circular buffer.
+ */
+
+static void serial_buf_clear(struct circ_buf *cb)
+{
+ cb->head = cb->tail = 0;
+}
+
+
+/*
+ * serial_buf_data_avail
+ *
+ * Return the number of bytes of data available in the circular
+ * buffer.
+ */
+
+static int serial_buf_data_avail(struct circ_buf *cb)
+{
+ return CIRC_CNT(cb->head,cb->tail,SERIAL_BUF_SIZE);
+}
+
+/*
+ * serial_buf_put
+ *
+ * Copy data data from a user buffer and put it into the circular buffer.
+ * Restrict to the amount of space available.
+ *
+ * Return the number of bytes copied.
+ */
+
+static int serial_buf_put(struct circ_buf *cb, const char *buf, int count)
+{
+ int c, ret = 0;
+
+ while (1) {
+ c = CIRC_SPACE_TO_END(cb->head, cb->tail, SERIAL_BUF_SIZE);
+ if (count < c)
+ c = count;
+ if (c <= 0)
+ break;
+ memcpy(cb->buf + cb->head, buf, c);
+ cb->head = (cb->head + c) & (SERIAL_BUF_SIZE-1);
+ buf += c;
+ count -= c;
+ ret += c;
+ }
+
+ return ret;
+}
+
+/*
+ * serial_buf_get
+ *
+ * Get data from the circular buffer and copy to the given buffer.
+ * Restrict to the amount of data available.
+ *
+ * Return the number of bytes copied.
+ */
+
+static int serial_buf_get(struct circ_buf *cb, char *buf, int count)
+{
+ int c, ret = 0;
+
+ while (1) {
+ c = CIRC_CNT_TO_END(cb->head, cb->tail, SERIAL_BUF_SIZE);
+ if (count < c)
+ c = count;
+ if (c <= 0)
+ break;
+ memcpy(buf, cb->buf + cb->tail, c);
+ cb->tail = (cb->tail + c) & (SERIAL_BUF_SIZE-1);
+ buf += c;
+ count -= c;
+ ret += c;
+ }
+
+ return ret;
+}
+
static int __init ftdi_init (void)
{
int retval;
-
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