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path: root/drivers/usb/serial/cp210x.c
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Diffstat (limited to 'drivers/usb/serial/cp210x.c')
-rw-r--r--drivers/usb/serial/cp210x.c186
1 files changed, 162 insertions, 24 deletions
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index 7a76fe4c2..73a366de5 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -38,13 +38,14 @@ static void cp210x_change_speed(struct tty_struct *, struct usb_serial_port *,
struct ktermios *);
static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
struct ktermios*);
+static bool cp210x_tx_empty(struct usb_serial_port *port);
static int cp210x_tiocmget(struct tty_struct *);
static int cp210x_tiocmset(struct tty_struct *, unsigned int, unsigned int);
static int cp210x_tiocmset_port(struct usb_serial_port *port,
unsigned int, unsigned int);
static void cp210x_break_ctl(struct tty_struct *, int);
-static int cp210x_startup(struct usb_serial *);
-static void cp210x_release(struct usb_serial *);
+static int cp210x_port_probe(struct usb_serial_port *);
+static int cp210x_port_remove(struct usb_serial_port *);
static void cp210x_dtr_rts(struct usb_serial_port *p, int on);
static const struct usb_device_id id_table[] = {
@@ -201,8 +202,9 @@ static const struct usb_device_id id_table[] = {
MODULE_DEVICE_TABLE(usb, id_table);
-struct cp210x_serial_private {
+struct cp210x_port_private {
__u8 bInterfaceNumber;
+ bool has_swapped_line_ctl;
};
static struct usb_serial_driver cp210x_device = {
@@ -218,10 +220,11 @@ static struct usb_serial_driver cp210x_device = {
.close = cp210x_close,
.break_ctl = cp210x_break_ctl,
.set_termios = cp210x_set_termios,
+ .tx_empty = cp210x_tx_empty,
.tiocmget = cp210x_tiocmget,
.tiocmset = cp210x_tiocmset,
- .attach = cp210x_startup,
- .release = cp210x_release,
+ .port_probe = cp210x_port_probe,
+ .port_remove = cp210x_port_remove,
.dtr_rts = cp210x_dtr_rts
};
@@ -304,6 +307,25 @@ static struct usb_serial_driver * const serial_drivers[] = {
#define CONTROL_WRITE_DTR 0x0100
#define CONTROL_WRITE_RTS 0x0200
+/* CP210X_GET_COMM_STATUS returns these 0x13 bytes */
+struct cp210x_comm_status {
+ __le32 ulErrors;
+ __le32 ulHoldReasons;
+ __le32 ulAmountInInQueue;
+ __le32 ulAmountInOutQueue;
+ u8 bEofReceived;
+ u8 bWaitForImmediate;
+ u8 bReserved;
+} __packed;
+
+/*
+ * CP210X_PURGE - 16 bits passed in wValue of USB request.
+ * SiLabs app note AN571 gives a strange description of the 4 bits:
+ * bit 0 or bit 2 clears the transmit queue and 1 or 3 receive.
+ * writing 1 to all, however, purges cp2108 well enough to avoid the hang.
+ */
+#define PURGE_ALL 0x000f
+
/*
* cp210x_get_config
* Reads from the CP210x configuration registers
@@ -315,7 +337,7 @@ static int cp210x_get_config(struct usb_serial_port *port, u8 request,
unsigned int *data, int size)
{
struct usb_serial *serial = port->serial;
- struct cp210x_serial_private *spriv = usb_get_serial_data(serial);
+ struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
__le32 *buf;
int result, i, length;
@@ -329,7 +351,7 @@ static int cp210x_get_config(struct usb_serial_port *port, u8 request,
/* Issue the request, attempting to read 'size' bytes */
result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
request, REQTYPE_INTERFACE_TO_HOST, 0x0000,
- spriv->bInterfaceNumber, buf, size,
+ port_priv->bInterfaceNumber, buf, size,
USB_CTRL_GET_TIMEOUT);
/* Convert data into an array of integers */
@@ -360,7 +382,7 @@ static int cp210x_set_config(struct usb_serial_port *port, u8 request,
unsigned int *data, int size)
{
struct usb_serial *serial = port->serial;
- struct cp210x_serial_private *spriv = usb_get_serial_data(serial);
+ struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
__le32 *buf;
int result, i, length;
@@ -379,13 +401,13 @@ static int cp210x_set_config(struct usb_serial_port *port, u8 request,
result = usb_control_msg(serial->dev,
usb_sndctrlpipe(serial->dev, 0),
request, REQTYPE_HOST_TO_INTERFACE, 0x0000,
- spriv->bInterfaceNumber, buf, size,
+ port_priv->bInterfaceNumber, buf, size,
USB_CTRL_SET_TIMEOUT);
} else {
result = usb_control_msg(serial->dev,
usb_sndctrlpipe(serial->dev, 0),
request, REQTYPE_HOST_TO_INTERFACE, data[0],
- spriv->bInterfaceNumber, NULL, 0,
+ port_priv->bInterfaceNumber, NULL, 0,
USB_CTRL_SET_TIMEOUT);
}
@@ -415,6 +437,60 @@ static inline int cp210x_set_config_single(struct usb_serial_port *port,
}
/*
+ * Detect CP2108 GET_LINE_CTL bug and activate workaround.
+ * Write a known good value 0x800, read it back.
+ * If it comes back swapped the bug is detected.
+ * Preserve the original register value.
+ */
+static int cp210x_detect_swapped_line_ctl(struct usb_serial_port *port)
+{
+ struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
+ unsigned int line_ctl_save;
+ unsigned int line_ctl_test;
+ int err;
+
+ err = cp210x_get_config(port, CP210X_GET_LINE_CTL, &line_ctl_save, 2);
+ if (err)
+ return err;
+
+ line_ctl_test = 0x800;
+ err = cp210x_set_config(port, CP210X_SET_LINE_CTL, &line_ctl_test, 2);
+ if (err)
+ return err;
+
+ err = cp210x_get_config(port, CP210X_GET_LINE_CTL, &line_ctl_test, 2);
+ if (err)
+ return err;
+
+ if (line_ctl_test == 8) {
+ port_priv->has_swapped_line_ctl = true;
+ line_ctl_save = swab16((u16)line_ctl_save);
+ }
+
+ return cp210x_set_config(port, CP210X_SET_LINE_CTL, &line_ctl_save, 2);
+}
+
+/*
+ * Must always be called instead of cp210x_get_config(CP210X_GET_LINE_CTL)
+ * to workaround cp2108 bug and get correct value.
+ */
+static int cp210x_get_line_ctl(struct usb_serial_port *port, unsigned int *ctl)
+{
+ struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
+ int err;
+
+ err = cp210x_get_config(port, CP210X_GET_LINE_CTL, ctl, 2);
+ if (err)
+ return err;
+
+ /* Workaround swapped bytes in 16-bit value from CP210X_GET_LINE_CTL */
+ if (port_priv->has_swapped_line_ctl)
+ *ctl = swab16((u16)(*ctl));
+
+ return 0;
+}
+
+/*
* cp210x_quantise_baudrate
* Quantises the baud rate as per AN205 Table 1
*/
@@ -479,11 +555,63 @@ static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
static void cp210x_close(struct usb_serial_port *port)
{
+ unsigned int purge_ctl;
+
usb_serial_generic_close(port);
+
+ /* Clear both queues; cp2108 needs this to avoid an occasional hang */
+ purge_ctl = PURGE_ALL;
+ cp210x_set_config(port, CP210X_PURGE, &purge_ctl, 2);
+
cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
}
/*
+ * Read how many bytes are waiting in the TX queue.
+ */
+static int cp210x_get_tx_queue_byte_count(struct usb_serial_port *port,
+ u32 *count)
+{
+ struct usb_serial *serial = port->serial;
+ struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
+ struct cp210x_comm_status *sts;
+ int result;
+
+ sts = kmalloc(sizeof(*sts), GFP_KERNEL);
+ if (!sts)
+ return -ENOMEM;
+
+ result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+ CP210X_GET_COMM_STATUS, REQTYPE_INTERFACE_TO_HOST,
+ 0, port_priv->bInterfaceNumber, sts, sizeof(*sts),
+ USB_CTRL_GET_TIMEOUT);
+ if (result == sizeof(*sts)) {
+ *count = le32_to_cpu(sts->ulAmountInOutQueue);
+ result = 0;
+ } else {
+ dev_err(&port->dev, "failed to get comm status: %d\n", result);
+ if (result >= 0)
+ result = -EPROTO;
+ }
+
+ kfree(sts);
+
+ return result;
+}
+
+static bool cp210x_tx_empty(struct usb_serial_port *port)
+{
+ int err;
+ u32 count;
+
+ err = cp210x_get_tx_queue_byte_count(port, &count);
+ if (err)
+ return true;
+
+ return !count;
+}
+
+/*
* cp210x_get_termios
* Reads the baud rate, data bits, parity, stop bits and flow control mode
* from the device, corrects any unsupported values, and configures the
@@ -524,7 +652,7 @@ static void cp210x_get_termios_port(struct usb_serial_port *port,
cflag = *cflagp;
- cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
+ cp210x_get_line_ctl(port, &bits);
cflag &= ~CSIZE;
switch (bits & BITS_DATA_MASK) {
case BITS_DATA_5:
@@ -692,7 +820,7 @@ static void cp210x_set_termios(struct tty_struct *tty,
/* If the number of data bits is to be updated */
if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
- cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
+ cp210x_get_line_ctl(port, &bits);
bits &= ~BITS_DATA_MASK;
switch (cflag & CSIZE) {
case CS5:
@@ -726,7 +854,7 @@ static void cp210x_set_termios(struct tty_struct *tty,
if ((cflag & (PARENB|PARODD|CMSPAR)) !=
(old_cflag & (PARENB|PARODD|CMSPAR))) {
- cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
+ cp210x_get_line_ctl(port, &bits);
bits &= ~BITS_PARITY_MASK;
if (cflag & PARENB) {
if (cflag & CMSPAR) {
@@ -752,7 +880,7 @@ static void cp210x_set_termios(struct tty_struct *tty,
}
if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
- cp210x_get_config(port, CP210X_GET_LINE_CTL, &bits, 2);
+ cp210x_get_line_ctl(port, &bits);
bits &= ~BITS_STOP_MASK;
if (cflag & CSTOPB) {
bits |= BITS_STOP_2;
@@ -867,29 +995,39 @@ static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
}
-static int cp210x_startup(struct usb_serial *serial)
+static int cp210x_port_probe(struct usb_serial_port *port)
{
+ struct usb_serial *serial = port->serial;
struct usb_host_interface *cur_altsetting;
- struct cp210x_serial_private *spriv;
+ struct cp210x_port_private *port_priv;
+ int ret;
- spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
- if (!spriv)
+ port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
+ if (!port_priv)
return -ENOMEM;
cur_altsetting = serial->interface->cur_altsetting;
- spriv->bInterfaceNumber = cur_altsetting->desc.bInterfaceNumber;
+ port_priv->bInterfaceNumber = cur_altsetting->desc.bInterfaceNumber;
+
+ usb_set_serial_port_data(port, port_priv);
- usb_set_serial_data(serial, spriv);
+ ret = cp210x_detect_swapped_line_ctl(port);
+ if (ret) {
+ kfree(port_priv);
+ return ret;
+ }
return 0;
}
-static void cp210x_release(struct usb_serial *serial)
+static int cp210x_port_remove(struct usb_serial_port *port)
{
- struct cp210x_serial_private *spriv;
+ struct cp210x_port_private *port_priv;
+
+ port_priv = usb_get_serial_port_data(port);
+ kfree(port_priv);
- spriv = usb_get_serial_data(serial);
- kfree(spriv);
+ return 0;
}
module_usb_serial_driver(serial_drivers, id_table);