+/*
+ * CP2101 supports the following baud rates:
+ *
+ * 300, 600, 1200, 1800, 2400, 4800, 7200, 9600, 14400, 19200, 28800,
+ * 38400, 56000, 57600, 115200, 128000, 230400, 460800, 921600
+ *
+ * CP2102 and CP2103 support the following additional rates:
+ *
+ * 4000, 16000, 51200, 64000, 76800, 153600, 250000, 256000, 500000,
+ * 576000
+ *
+ * The device will map a requested rate to a supported one, but the result
+ * of requests for rates greater than 1053257 is undefined (see AN205).
+ *
+ * CP2104, CP2105 and CP2110 support most rates up to 2M, 921k and 1M baud,
+ * respectively, with an error less than 1%. The actual rates are determined
+ * by
+ *
+ * div = round(freq / (2 x prescale x request))
+ * actual = freq / (2 x prescale x div)
+ *
+ * For CP2104 and CP2105 freq is 48Mhz and prescale is 4 for request <= 365bps
+ * or 1 otherwise.
+ * For CP2110 freq is 24Mhz and prescale is 4 for request <= 300bps or 1
+ * otherwise.
+ */
+static void cp210x_change_speed(struct tty_struct *tty,
+ struct usb_serial_port *port, struct ktermios *old_termios)
+{
+ u32 baud;
+
+ baud = tty->termios->c_ospeed;
+
+ /* This maps the requested rate to a rate valid on cp2102 or cp2103,
+ * or to an arbitrary rate in [1M,2M].
+ *
+ * NOTE: B0 is not implemented.
+ */
+ baud = cp210x_quantise_baudrate(baud);
+
+ dbg("%s - setting baud rate to %u", __func__, baud);
+ if (cp210x_set_config(port, CP210X_SET_BAUDRATE, &baud,
+ sizeof(baud))) {
+ dev_warn(&port->dev, "failed to set baud rate to %u\n", baud);
+ if (old_termios)
+ baud = old_termios->c_ospeed;
+ else
+ baud = 9600;
+ }
+
+ tty_encode_baud_rate(tty, baud, baud);
+}
+
+static void cp210x_set_termios(struct tty_struct *tty,
+ struct usb_serial_port *port, struct ktermios *old_termios)