*
*
* Lonnie Mendez <dignome@gmail.com>
+ * 12-15-2004
+ * Incorporated write buffering from pl2303 driver. Fixed bug with line
+ * handling so both lines are raised in cypress_open. (was dropping rts)
+ * Various code cleanups made as well along with other misc bug fixes.
+ *
+ * Lonnie Mendez <dignome@gmail.com>
* 04-10-2004
* Driver modified to support dynamic line settings. Various improvments
* and features.
* Long Term TODO:
* Improve transfer speeds - both read/write are somewhat slow
* at this point.
+ * Improve debugging. Show modem line status with debug output and
+ * implement filtering for certain data as a module parameter.
*/
-/* Neil Whelchel wrote the cypress m8 implementation */
+/* Thanks to Neil Whelchel for writing the first cypress m8 implementation for linux. */
/* Thanks to cypress for providing references for the hid reports. */
/* Thanks to Jiang Zhang for providing links and for general help. */
/* Code originates and was built up from ftdi_sio, belkin, pl2303 and others. */
#include <linux/usb.h>
#include <linux/serial.h>
+#include "usb-serial.h"
+#include "cypress_m8.h"
+
+
#ifdef CONFIG_USB_SERIAL_DEBUG
static int debug = 1;
#else
static int debug;
#endif
-
static int stats;
-#include "usb-serial.h"
-#include "cypress_m8.h"
-
/*
* Version Information
*/
-#define DRIVER_VERSION "v1.06"
+#define DRIVER_VERSION "v1.08"
#define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
#define DRIVER_DESC "Cypress USB to Serial Driver"
+/* write buffer size defines */
+#define CYPRESS_BUF_SIZE 1024
+#define CYPRESS_CLOSING_WAIT (30*HZ)
+
static struct usb_device_id id_table_earthmate [] = {
{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
{ } /* Terminating entry */
int bytes_out; /* used for statistics */
int cmd_count; /* used for statistics */
int cmd_ctrl; /* always set this to 1 before issuing a command */
+ struct cypress_buf *buf; /* write buffer */
+ int write_urb_in_use; /* write urb in use indicator */
int termios_initialized;
__u8 line_control; /* holds dtr / rts value */
__u8 current_status; /* received from last read - info on dsr,cts,cd,ri,etc */
char prev_status, diff_status; /* used for TIOCMIWAIT */
/* we pass a pointer to this as the arguement sent to cypress_set_termios old_termios */
struct termios tmp_termios; /* stores the old termios settings */
- int write_interval; /* interrupt out write interval, as obtained from interrupt_out_urb */
- int writepipe; /* used for clear halt, if necessary */
+ char calledfromopen; /* used when issuing lines on open - fixes rts drop bug */
+};
+
+/* write buffer structure */
+struct cypress_buf {
+ unsigned int buf_size;
+ char *buf_buf;
+ char *buf_get;
+ char *buf_put;
};
/* function prototypes for the Cypress USB to serial device */
static int cypress_open (struct usb_serial_port *port, struct file *filp);
static void cypress_close (struct usb_serial_port *port, struct file *filp);
static int cypress_write (struct usb_serial_port *port, const unsigned char *buf, int count);
+static void cypress_send (struct usb_serial_port *port);
static int cypress_write_room (struct usb_serial_port *port);
static int cypress_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
static void cypress_set_termios (struct usb_serial_port *port, struct termios * old);
static void cypress_unthrottle (struct usb_serial_port *port);
static void cypress_read_int_callback (struct urb *urb, struct pt_regs *regs);
static void cypress_write_int_callback (struct urb *urb, struct pt_regs *regs);
-static int mask_to_rate (unsigned mask);
-static unsigned rate_to_mask (int rate);
+/* baud helper functions */
+static int mask_to_rate (unsigned mask);
+static unsigned rate_to_mask (int rate);
+/* write buffer functions */
+static struct cypress_buf *cypress_buf_alloc(unsigned int size);
+static void cypress_buf_free(struct cypress_buf *cb);
+static void cypress_buf_clear(struct cypress_buf *cb);
+static unsigned int cypress_buf_data_avail(struct cypress_buf *cb);
+static unsigned int cypress_buf_space_avail(struct cypress_buf *cb);
+static unsigned int cypress_buf_put(struct cypress_buf *cb, const char *buf,
+ unsigned int count);
+static unsigned int cypress_buf_get(struct cypress_buf *cb, char *buf,
+ unsigned int count);
+
static struct usb_serial_device_type cypress_earthmate_device = {
.owner = THIS_MODULE,
memset(priv, 0x00, sizeof (struct cypress_private));
spin_lock_init(&priv->lock);
+ priv->buf = cypress_buf_alloc(CYPRESS_BUF_SIZE);
+ if (priv->buf == NULL) {
+ kfree(priv);
+ return -ENOMEM;
+ }
init_waitqueue_head(&priv->delta_msr_wait);
- priv->writepipe = serial->port[0]->interrupt_out_urb->pipe;
- /* free up interrupt_out buffer / urb allocated by usbserial
- * for this port as we use our own urbs for writing */
- if (serial->port[0]->interrupt_out_buffer) {
- kfree(serial->port[0]->interrupt_out_buffer);
- serial->port[0]->interrupt_out_buffer = NULL;
- }
- if (serial->port[0]->interrupt_out_urb) {
- priv->write_interval = serial->port[0]->interrupt_out_urb->interval;
- usb_free_urb(serial->port[0]->interrupt_out_urb);
- serial->port[0]->interrupt_out_urb = NULL;
- } else /* still need a write interval */
- priv->write_interval = 10;
-
+ usb_reset_configuration (serial->dev);
+
priv->cmd_ctrl = 0;
priv->line_control = 0;
priv->termios_initialized = 0;
+ priv->calledfromopen = 0;
priv->rx_flags = 0;
usb_set_serial_port_data(serial->port[0], priv);
priv = usb_get_serial_port_data(serial->port[0]);
if (priv) {
+ cypress_buf_free(priv->buf);
kfree(priv);
usb_set_serial_port_data(serial->port[0], NULL);
}
dbg("%s - port %d", __FUNCTION__, port->number);
+ /* clear halts before open */
+ usb_clear_halt(serial->dev, 0x00);
+ usb_clear_halt(serial->dev, 0x81);
+ usb_clear_halt(serial->dev, 0x02);
+
spin_lock_irqsave(&priv->lock, flags);
/* reset read/write statistics */
priv->bytes_in = 0;
priv->bytes_out = 0;
priv->cmd_count = 0;
-
- /* turn on dtr / rts since we are not flow controlling by default */
- priv->line_control = CONTROL_DTR | CONTROL_RTS; /* sent in status byte */
+ priv->rx_flags = 0;
spin_unlock_irqrestore(&priv->lock, flags);
- priv->cmd_ctrl = 1;
- result = cypress_write(port, NULL, 0);
-
+
+ /* setting to zero could cause data loss */
port->tty->low_latency = 1;
- /* termios defaults are set by usb_serial_init */
-
- cypress_set_termios(port, &priv->tmp_termios);
+ /* raise both lines and set termios */
+ spin_lock_irqsave(&priv->lock, flags);
+ priv->line_control = CONTROL_DTR | CONTROL_RTS;
+ priv->calledfromopen = 1;
+ priv->cmd_ctrl = 1;
+ spin_unlock_irqrestore(&priv->lock, flags);
+ result = cypress_write(port, NULL, 0);
if (result) {
dev_err(&port->dev, "%s - failed setting the control lines - error %d\n", __FUNCTION__, result);
return result;
} else
- dbg("%s - success setting the control lines", __FUNCTION__);
+ dbg("%s - success setting the control lines", __FUNCTION__);
- /* throttling off */
- spin_lock_irqsave(&priv->lock, flags);
- priv->rx_flags = 0;
- spin_unlock_irqrestore(&priv->lock, flags);
+ cypress_set_termios(port, &priv->tmp_termios);
- /* setup the port and
- * start reading from the device */
+ /* setup the port and start reading from the device */
if(!port->interrupt_in_urb){
err("%s - interrupt_in_urb is empty!", __FUNCTION__);
return(-1);
struct cypress_private *priv = usb_get_serial_port_data(port);
unsigned int c_cflag;
unsigned long flags;
+ int bps;
+ long timeout;
+ wait_queue_t wait;
dbg("%s - port %d", __FUNCTION__, port->number);
+ /* wait for data to drain from buffer */
+ spin_lock_irqsave(&priv->lock, flags);
+ timeout = CYPRESS_CLOSING_WAIT;
+ init_waitqueue_entry(&wait, current);
+ add_wait_queue(&port->tty->write_wait, &wait);
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (cypress_buf_data_avail(priv->buf) == 0
+ || timeout == 0 || signal_pending(current)
+ || !usb_get_intfdata(port->serial->interface))
+ break;
+ spin_unlock_irqrestore(&priv->lock, flags);
+ timeout = schedule_timeout(timeout);
+ spin_lock_irqsave(&priv->lock, flags);
+ }
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&port->tty->write_wait, &wait);
+ /* clear out any remaining data in the buffer */
+ cypress_buf_clear(priv->buf);
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ /* wait for characters to drain from device */
+ bps = tty_get_baud_rate(port->tty);
+ if (bps > 1200)
+ timeout = max((HZ*2560)/bps,HZ/10);
+ else
+ timeout = 2*HZ;
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(timeout);
+
+ dbg("%s - stopping urbs", __FUNCTION__);
+ usb_kill_urb (port->interrupt_in_urb);
+ usb_kill_urb (port->interrupt_out_urb);
+
if (port->tty) {
c_cflag = port->tty->termios->c_cflag;
if (c_cflag & HUPCL) {
}
}
- if (port->interrupt_in_urb) {
- dbg("%s - stopping read urb", __FUNCTION__);
- usb_kill_urb (port->interrupt_in_urb);
- }
-
if (stats)
dev_info (&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
priv->bytes_in, priv->bytes_out, priv->cmd_count);
{
struct cypress_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
- struct urb *urb;
- int status, s_pos = 0;
- __u8 transfer_size = 0;
- __u8 *buffer;
-
- dbg("%s - port %d", __FUNCTION__, port->number);
+
+ dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);
- spin_lock_irqsave(&priv->lock, flags);
- if (count == 0 && !priv->cmd_ctrl) {
- spin_unlock_irqrestore(&priv->lock, flags);
- dbg("%s - write request of 0 bytes", __FUNCTION__);
- return 0;
+ /* line control commands, which need to be executed immediately,
+ are not put into the buffer for obvious reasons.
+ */
+ if (priv->cmd_ctrl) {
+ count = 0;
+ goto finish;
}
-
- if (priv->cmd_ctrl)
- ++priv->cmd_count;
- priv->cmd_ctrl = 0;
+
+ if (!count)
+ return count;
+
+ spin_lock_irqsave(&priv->lock, flags);
+ count = cypress_buf_put(priv->buf, buf, count);
spin_unlock_irqrestore(&priv->lock, flags);
- dbg("%s - interrupt out size is %d", __FUNCTION__, port->interrupt_out_size);
- dbg("%s - count is %d", __FUNCTION__, count);
+finish:
+ cypress_send(port);
- /* Allocate buffer and urb */
- buffer = kmalloc (port->interrupt_out_size, GFP_ATOMIC);
- if (!buffer) {
- dev_err(&port->dev, "ran out of memory for buffer\n");
- return -ENOMEM;
- }
+ return count;
+} /* cypress_write */
- urb = usb_alloc_urb (0, GFP_ATOMIC);
- if (!urb) {
- dev_err(&port->dev, "failed allocating write urb\n");
- kfree (buffer);
- return -ENOMEM;
+
+static void cypress_send(struct usb_serial_port *port)
+{
+ int count = 0, result, offset, actual_size;
+ struct cypress_private *priv = usb_get_serial_port_data(port);
+ unsigned long flags;
+
+ dbg("%s - port %d", __FUNCTION__, port->number);
+ dbg("%s - interrupt out size is %d", __FUNCTION__, port->interrupt_out_size);
+
+ spin_lock_irqsave(&priv->lock, flags);
+ if (priv->write_urb_in_use) {
+ dbg("%s - can't write, urb in use", __FUNCTION__);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ return;
}
+ spin_unlock_irqrestore(&priv->lock, flags);
- memset(buffer, 0, port->interrupt_out_size); // test if this is needed... probably not since loop removed
+ /* clear buffer */
+ memset(port->interrupt_out_urb->transfer_buffer, 0, port->interrupt_out_size);
spin_lock_irqsave(&priv->lock, flags);
switch (port->interrupt_out_size) {
case 32:
// this is for the CY7C64013...
- transfer_size = min (count, 30);
- buffer[0] = priv->line_control;
- buffer[1] = transfer_size;
- s_pos = 2;
+ offset = 2;
+ port->interrupt_out_buffer[0] = priv->line_control;
break;
case 8:
// this is for the CY7C63743...
- transfer_size = min (count, 7);
- buffer[0] = priv->line_control | transfer_size;
- s_pos = 1;
+ offset = 1;
+ port->interrupt_out_buffer[0] = priv->line_control;
break;
default:
dbg("%s - wrong packet size", __FUNCTION__);
spin_unlock_irqrestore(&priv->lock, flags);
- kfree (buffer);
- usb_free_urb (urb);
- return -1;
+ return;
}
if (priv->line_control & CONTROL_RESET)
priv->line_control &= ~CONTROL_RESET;
- spin_unlock_irqrestore(&priv->lock, flags);
-
- /* copy data to offset position in urb transfer buffer */
- memcpy (&buffer[s_pos], buf, transfer_size);
- usb_serial_debug_data (debug, &port->dev, __FUNCTION__, port->interrupt_out_size, buffer);
+ if (priv->cmd_ctrl) {
+ priv->cmd_count++;
+ dbg("%s - line control command being issued", __FUNCTION__);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ goto send;
+ } else
+ spin_unlock_irqrestore(&priv->lock, flags);
- /* build up the urb */
- usb_fill_int_urb (urb, port->serial->dev,
- usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
- buffer, port->interrupt_out_size,
- cypress_write_int_callback, port, priv->write_interval);
+ count = cypress_buf_get(priv->buf, &port->interrupt_out_buffer[offset],
+ port->interrupt_out_size-offset);
- status = usb_submit_urb(urb, GFP_ATOMIC);
+ if (count == 0) {
+ return;
+ }
- if (status) {
- dev_err(&port->dev, "%s - usb_submit_urb (write interrupt) failed with status %d\n",
- __FUNCTION__, status);
- transfer_size = status;
- kfree (buffer);
- goto exit;
+ switch (port->interrupt_out_size) {
+ case 32:
+ port->interrupt_out_buffer[1] = count;
+ break;
+ case 8:
+ port->interrupt_out_buffer[0] |= count;
}
+ dbg("%s - count is %d", __FUNCTION__, count);
+
+send:
spin_lock_irqsave(&priv->lock, flags);
- priv->bytes_out += transfer_size;
+ priv->write_urb_in_use = 1;
spin_unlock_irqrestore(&priv->lock, flags);
-exit:
- /* buffer free'd in callback */
- usb_free_urb (urb);
+ if (priv->cmd_ctrl)
+ actual_size = 1;
+ else
+ actual_size = count + (port->interrupt_out_size == 32 ? 2 : 1);
+
+ usb_serial_debug_data(debug, &port->dev, __FUNCTION__, port->interrupt_out_size,
+ port->interrupt_out_urb->transfer_buffer);
- return transfer_size;
+ port->interrupt_out_urb->transfer_buffer_length = actual_size;
+ port->interrupt_out_urb->dev = port->serial->dev;
+ result = usb_submit_urb (port->interrupt_out_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;
+ }
-} /* cypress_write */
+ spin_lock_irqsave(&priv->lock, flags);
+ if (priv->cmd_ctrl) {
+ priv->cmd_ctrl = 0;
+ }
+ priv->bytes_out += count; /* do not count the line control and size bytes */
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ schedule_work(&port->work);
+} /* cypress_send */
+/* returns how much space is available in the soft buffer */
static int cypress_write_room(struct usb_serial_port *port)
{
+ struct cypress_private *priv = usb_get_serial_port_data(port);
+ int room = 0;
+ unsigned long flags;
+
dbg("%s - port %d", __FUNCTION__, port->number);
- /*
- * We really can take anything the user throw at us
- * but let's pick a nice big number to tell the tty
- * layer that we have lots of free space
- */
+ spin_lock_irqsave(&priv->lock, flags);
+ room = cypress_buf_space_avail(priv->buf);
+ spin_unlock_irqrestore(&priv->lock, flags);
- return 2048;
+ dbg("%s - returns %d", __FUNCTION__, room);
+ return room;
}
int data_bits, stop_bits, parity_type, parity_enable;
unsigned cflag, iflag, baud_mask;
unsigned long flags;
+ __u8 oldlines;
+ int linechange;
dbg("%s - port %d", __FUNCTION__, port->number);
data_bits = 3;
spin_lock_irqsave(&priv->lock, flags);
+ oldlines = priv->line_control;
if ((cflag & CBAUD) == B0) {
/* drop dtr and rts */
dbg("%s - dropping the lines, baud rate 0bps", __FUNCTION__);
}
priv->line_control |= CONTROL_DTR;
- /* this is probably not what I think it is... check into it */
- if (cflag & CRTSCTS)
- priv->line_control |= CONTROL_RTS;
- else
- priv->line_control &= ~CONTROL_RTS;
+ /* toggle CRTSCTS? - don't do this if being called from cypress_open */
+ if (!priv->calledfromopen) {
+ if (cflag & CRTSCTS)
+ priv->line_control |= CONTROL_RTS;
+ else
+ priv->line_control &= ~CONTROL_RTS;
+ }
}
spin_unlock_irqrestore(&priv->lock, flags);
/* Here we can define custom tty settings for devices
*
- * the main tty base comes from empeg.c
+ * the main tty termios flag base comes from empeg.c
*/
spin_lock_irqsave(&priv->lock, flags);
// Software app handling it for device...
- } else {
-
- /* do something here */
-
}
+ linechange = (priv->line_control != oldlines);
spin_unlock_irqrestore(&priv->lock, flags);
- /* set lines */
- priv->cmd_ctrl = 1;
- cypress_write(port, NULL, 0);
+ /* if necessary, set lines */
+ if (!priv->calledfromopen && linechange) {
+ priv->cmd_ctrl = 1;
+ cypress_write(port, NULL, 0);
+ }
+
+ if (priv->calledfromopen)
+ priv->calledfromopen = 0;
- return;
} /* cypress_set_termios */
-
+
+/* returns amount of data still left in soft buffer */
static int cypress_chars_in_buffer(struct usb_serial_port *port)
{
- dbg("%s - port %d", __FUNCTION__, port->number);
+ struct cypress_private *priv = usb_get_serial_port_data(port);
+ int chars = 0;
+ unsigned long flags;
- /*
- * We can't really account for how much data we
- * have sent out, but hasn't made it through to the
- * device, so just tell the tty layer that everything
- * is flushed.
- */
+ dbg("%s - port %d", __FUNCTION__, port->number);
+
+ spin_lock_irqsave(&priv->lock, flags);
+ chars = cypress_buf_data_avail(priv->buf);
+ spin_unlock_irqrestore(&priv->lock, flags);
- return 0;
+ dbg("%s - returns %d", __FUNCTION__, chars);
+ return chars;
}
struct tty_struct *tty;
unsigned char *data = urb->transfer_buffer;
unsigned long flags;
- char tty_flag = TTY_NORMAL;
- int bytes=0;
+ char tty_flag = TTY_NORMAL;
+ int havedata = 0;
+ int bytes = 0;
int result;
- int i=0;
+ int i = 0;
dbg("%s - port %d", __FUNCTION__, port->number);
spin_lock_irqsave(&priv->lock, flags);
if (priv->rx_flags & THROTTLED) {
+ dbg("%s - now throttling", __FUNCTION__);
priv->rx_flags |= ACTUALLY_THROTTLED;
spin_unlock_irqrestore(&priv->lock, flags);
return;
return;
}
- usb_serial_debug_data (debug, &port->dev, __FUNCTION__, urb->actual_length, data);
-
spin_lock_irqsave(&priv->lock, flags);
switch(urb->actual_length) {
case 32:
priv->current_status = data[0] & 0xF8;
bytes = data[1]+2;
i=2;
+ if (bytes > 2)
+ havedata = 1;
break;
case 8:
// This is for the CY7C63743...
priv->current_status = data[0] & 0xF8;
bytes = (data[0] & 0x07)+1;
i=1;
+ if (bytes > 1)
+ havedata = 1;
break;
default:
dbg("%s - wrong packet size - received %d bytes", __FUNCTION__, urb->actual_length);
}
spin_unlock_irqrestore(&priv->lock, flags);
+ usb_serial_debug_data (debug, &port->dev, __FUNCTION__, urb->actual_length, data);
+
spin_lock_irqsave(&priv->lock, flags);
/* check to see if status has changed */
if (priv != NULL) {
/* process read if there is data other than line status */
if (tty && (bytes > i)) {
for (; i < bytes ; ++i) {
- dbg("pushing byte number %d - %d",i,data[i]);
+ dbg("pushing byte number %d - %d - %c",i,data[i],data[i]);
if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
tty_flip_buffer_push(tty);
}
static void cypress_write_int_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 cypress_private *priv = usb_get_serial_port_data(port);
+ int result;
dbg("%s - port %d", __FUNCTION__, port->number);
- if (urb->status) {
- dbg("%s - nonzero write status received: %d", __FUNCTION__, urb->status);
- return;
+ 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->interrupt_out_urb->transfer_buffer_length = 1;
+ port->interrupt_out_urb->dev = port->serial->dev;
+ result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
+ if (result)
+ dev_err(&urb->dev->dev, "%s - failed resubmitting write urb, error %d\n",
+ __FUNCTION__, result);
+ else
+ return;
}
+
+ priv->write_urb_in_use = 0;
+
+ /* send any buffered data */
+ cypress_send(port);
+}
- schedule_work(&port->work);
+
+/*****************************************************************************
+ * Write buffer functions - buffering code from pl2303 used
+ *****************************************************************************/
+
+/*
+ * cypress_buf_alloc
+ *
+ * Allocate a circular buffer and all associated memory.
+ */
+
+static struct cypress_buf *cypress_buf_alloc(unsigned int size)
+{
+
+ struct cypress_buf *cb;
+
+
+ if (size == 0)
+ return NULL;
+
+ cb = (struct cypress_buf *)kmalloc(sizeof(struct cypress_buf), GFP_KERNEL);
+ if (cb == NULL)
+ return NULL;
+
+ cb->buf_buf = kmalloc(size, GFP_KERNEL);
+ if (cb->buf_buf == NULL) {
+ kfree(cb);
+ return NULL;
+ }
+
+ cb->buf_size = size;
+ cb->buf_get = cb->buf_put = cb->buf_buf;
+
+ return cb;
+
+}
+
+
+/*
+ * cypress_buf_free
+ *
+ * Free the buffer and all associated memory.
+ */
+
+static void cypress_buf_free(struct cypress_buf *cb)
+{
+ if (cb != NULL) {
+ if (cb->buf_buf != NULL)
+ kfree(cb->buf_buf);
+ kfree(cb);
+ }
+}
+
+
+/*
+ * cypress_buf_clear
+ *
+ * Clear out all data in the circular buffer.
+ */
+
+static void cypress_buf_clear(struct cypress_buf *cb)
+{
+ if (cb != NULL)
+ cb->buf_get = cb->buf_put;
+ /* equivalent to a get of all data available */
}
+/*
+ * cypress_buf_data_avail
+ *
+ * Return the number of bytes of data available in the circular
+ * buffer.
+ */
+
+static unsigned int cypress_buf_data_avail(struct cypress_buf *cb)
+{
+ if (cb != NULL)
+ return ((cb->buf_size + cb->buf_put - cb->buf_get) % cb->buf_size);
+ else
+ return 0;
+}
+
+
+/*
+ * cypress_buf_space_avail
+ *
+ * Return the number of bytes of space available in the circular
+ * buffer.
+ */
+
+static unsigned int cypress_buf_space_avail(struct cypress_buf *cb)
+{
+ if (cb != NULL)
+ return ((cb->buf_size + cb->buf_get - cb->buf_put - 1) % cb->buf_size);
+ else
+ return 0;
+}
+
+
+/*
+ * cypress_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 unsigned int cypress_buf_put(struct cypress_buf *cb, const char *buf,
+ unsigned int count)
+{
+
+ unsigned int len;
+
+
+ if (cb == NULL)
+ return 0;
+
+ len = cypress_buf_space_avail(cb);
+ if (count > len)
+ count = len;
+
+ if (count == 0)
+ return 0;
+
+ len = cb->buf_buf + cb->buf_size - cb->buf_put;
+ if (count > len) {
+ memcpy(cb->buf_put, buf, len);
+ memcpy(cb->buf_buf, buf+len, count - len);
+ cb->buf_put = cb->buf_buf + count - len;
+ } else {
+ memcpy(cb->buf_put, buf, count);
+ if (count < len)
+ cb->buf_put += count;
+ else /* count == len */
+ cb->buf_put = cb->buf_buf;
+ }
+
+ return count;
+
+}
+
+
+/*
+ * cypress_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 unsigned int cypress_buf_get(struct cypress_buf *cb, char *buf,
+ unsigned int count)
+{
+
+ unsigned int len;
+
+
+ if (cb == NULL)
+ return 0;
+
+ len = cypress_buf_data_avail(cb);
+ if (count > len)
+ count = len;
+
+ if (count == 0)
+ return 0;
+
+ len = cb->buf_buf + cb->buf_size - cb->buf_get;
+ if (count > len) {
+ memcpy(buf, cb->buf_get, len);
+ memcpy(buf+len, cb->buf_buf, count - len);
+ cb->buf_get = cb->buf_buf + count - len;
+ } else {
+ memcpy(buf, cb->buf_get, count);
+ if (count < len)
+ cb->buf_get += count;
+ else /* count == len */
+ cb->buf_get = cb->buf_buf;
+ }
+
+ return count;
+
+}
+
/*****************************************************************************
* Module functions
*****************************************************************************/
MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
+MODULE_VERSION( DRIVER_VERSION );
MODULE_LICENSE("GPL");
module_param(debug, bool, S_IRUGO | S_IWUSR);
git://git.onelab.eu / linux-2.6.git / blobdiff