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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.c64
1 files changed, 59 insertions, 5 deletions
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index c9f8ebd34122..fcb812bc832c 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -252,9 +252,11 @@ struct cp210x_serial_private {
u8 gpio_input;
#endif
u8 partnum;
+ u32 fw_version;
speed_t min_speed;
speed_t max_speed;
bool use_actual_rate;
+ bool no_flow_control;
};
enum cp210x_event_state {
@@ -398,6 +400,7 @@ struct cp210x_special_chars {
/* CP210X_VENDOR_SPECIFIC values */
#define CP210X_READ_2NCONFIG 0x000E
+#define CP210X_GET_FW_VER_2N 0x0010
#define CP210X_READ_LATCH 0x00C2
#define CP210X_GET_PARTNUM 0x370B
#define CP210X_GET_PORTCONFIG 0x370C
@@ -1128,6 +1131,7 @@ static bool cp210x_termios_change(const struct ktermios *a, const struct ktermio
static void cp210x_set_flow_control(struct tty_struct *tty,
struct usb_serial_port *port, struct ktermios *old_termios)
{
+ struct cp210x_serial_private *priv = usb_get_serial_data(port->serial);
struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
struct cp210x_special_chars chars;
struct cp210x_flow_ctl flow_ctl;
@@ -1135,6 +1139,15 @@ static void cp210x_set_flow_control(struct tty_struct *tty,
u32 ctl_hs;
int ret;
+ /*
+ * Some CP2102N interpret ulXonLimit as ulFlowReplace (erratum
+ * CP2102N_E104). Report back that flow control is not supported.
+ */
+ if (priv->no_flow_control) {
+ tty->termios.c_cflag &= ~CRTSCTS;
+ tty->termios.c_iflag &= ~(IXON | IXOFF);
+ }
+
if (old_termios &&
C_CRTSCTS(tty) == (old_termios->c_cflag & CRTSCTS) &&
I_IXON(tty) == (old_termios->c_iflag & IXON) &&
@@ -1191,19 +1204,20 @@ static void cp210x_set_flow_control(struct tty_struct *tty,
port_priv->crtscts = false;
}
- if (I_IXOFF(tty))
+ if (I_IXOFF(tty)) {
flow_repl |= CP210X_SERIAL_AUTO_RECEIVE;
- else
+
+ flow_ctl.ulXonLimit = cpu_to_le32(128);
+ flow_ctl.ulXoffLimit = cpu_to_le32(128);
+ } else {
flow_repl &= ~CP210X_SERIAL_AUTO_RECEIVE;
+ }
if (I_IXON(tty))
flow_repl |= CP210X_SERIAL_AUTO_TRANSMIT;
else
flow_repl &= ~CP210X_SERIAL_AUTO_TRANSMIT;
- flow_ctl.ulXonLimit = cpu_to_le32(128);
- flow_ctl.ulXoffLimit = cpu_to_le32(128);
-
dev_dbg(&port->dev, "%s - ctrl = 0x%02x, flow = 0x%02x\n", __func__,
ctl_hs, flow_repl);
@@ -1926,6 +1940,45 @@ static void cp210x_init_max_speed(struct usb_serial *serial)
priv->use_actual_rate = use_actual_rate;
}
+static int cp210x_get_fw_version(struct usb_serial *serial, u16 value)
+{
+ struct cp210x_serial_private *priv = usb_get_serial_data(serial);
+ u8 ver[3];
+ int ret;
+
+ ret = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST, value,
+ ver, sizeof(ver));
+ if (ret)
+ return ret;
+
+ dev_dbg(&serial->interface->dev, "%s - %d.%d.%d\n", __func__,
+ ver[0], ver[1], ver[2]);
+
+ priv->fw_version = ver[0] << 16 | ver[1] << 8 | ver[2];
+
+ return 0;
+}
+
+static void cp210x_determine_quirks(struct usb_serial *serial)
+{
+ struct cp210x_serial_private *priv = usb_get_serial_data(serial);
+ int ret;
+
+ switch (priv->partnum) {
+ case CP210X_PARTNUM_CP2102N_QFN28:
+ case CP210X_PARTNUM_CP2102N_QFN24:
+ case CP210X_PARTNUM_CP2102N_QFN20:
+ ret = cp210x_get_fw_version(serial, CP210X_GET_FW_VER_2N);
+ if (ret)
+ break;
+ if (priv->fw_version <= 0x10004)
+ priv->no_flow_control = true;
+ break;
+ default:
+ break;
+ }
+}
+
static int cp210x_attach(struct usb_serial *serial)
{
int result;
@@ -1946,6 +1999,7 @@ static int cp210x_attach(struct usb_serial *serial)
usb_set_serial_data(serial, priv);
+ cp210x_determine_quirks(serial);
cp210x_init_max_speed(serial);
result = cp210x_gpio_init(serial);