The CP2102N supports more baudrates than earlier chips by SiLabs. This patch adds support for all rates documented in the datasheet of this device. Signed-off-by: Karoly Pados <pados@xxxxxxxx> --- drivers/usb/serial/cp210x.c | 39 ++++++++++++++++++++++++++----------- 1 file changed, 28 insertions(+), 11 deletions(-) diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c index b1849f657e01..793b86252c46 100644 --- a/drivers/usb/serial/cp210x.c +++ b/drivers/usb/serial/cp210x.c @@ -357,6 +357,9 @@ static struct usb_serial_driver * const serial_drivers[] = { #define CP210X_PARTNUM_CP2104 0x04 #define CP210X_PARTNUM_CP2105 0x05 #define CP210X_PARTNUM_CP2108 0x08 +#define CP210X_PARTNUM_CP2102N_QFN28 0x20 +#define CP210X_PARTNUM_CP2102N_QFN24 0x21 +#define CP210X_PARTNUM_CP2102N_QFN20 0x22 #define CP210X_PARTNUM_UNKNOWN 0xFF /* CP210X_GET_COMM_STATUS returns these 0x13 bytes */ @@ -758,8 +761,12 @@ static int cp210x_get_line_ctl(struct usb_serial_port *port, u16 *ctl) /* * cp210x_quantise_baudrate * Quantises the baud rate as per AN205 Table 1 + * The CP2102N is fully (except for baud rate aliasing) software- + * compatible, but supports some additional baudrates. However, there is + * no quantitisation table available for this model, so in this case we + * take the supported baudrate which is closest to the requested one. */ -static unsigned int cp210x_quantise_baudrate(unsigned int baud) +static unsigned int cp210x_quantise_baudrate(unsigned int baud, bool cp2102n) { if (baud <= 300) baud = 300; @@ -790,10 +797,17 @@ static unsigned int cp210x_quantise_baudrate(unsigned int baud) else if (baud <= 491520) baud = 460800; else if (baud <= 567138) baud = 500000; else if (baud <= 670254) baud = 576000; - else if (baud < 1000000) - baud = 921600; - else if (baud > 2000000) - baud = 2000000; + else if (cp2102n) { + if (baud <= 960800) baud = 921600; + else if (baud <= 1100000) baud = 1000000; + else if (baud <= 1350000) baud = 1200000; + else if (baud <= 1750000) baud = 1500000; + else if (baud <= 2500000) baud = 2000000; + else baud = 3000000; + } else { + if (baud < 1000000) baud = 921600; + else if (baud > 2000000) baud = 2000000; + } return baud; } @@ -1045,16 +1059,19 @@ static void cp210x_get_termios_port(struct usb_serial_port *port, 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; + bool is_cp2102n; + u32 baud = tty->termios.c_ospeed; + struct cp210x_serial_private *priv = usb_get_serial_data(port->serial); - /* This maps the requested rate to a rate valid on cp2102 or cp2103, - * or to an arbitrary rate in [1M,2M]. + /* This maps the requested rate to a rate valid on cp2102(n) or + * cp2103 or to an arbitrary rate in [1M,2M]. * * NOTE: B0 is not implemented. */ - baud = cp210x_quantise_baudrate(baud); + is_cp2102n = (priv->partnum == CP210X_PARTNUM_CP2102N_QFN28) || + (priv->partnum == CP210X_PARTNUM_CP2102N_QFN24) || + (priv->partnum == CP210X_PARTNUM_CP2102N_QFN20); + baud = cp210x_quantise_baudrate(baud, is_cp2102n); dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud); if (cp210x_write_u32_reg(port, CP210X_SET_BAUDRATE, baud)) { -- 2.17.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html