diff options
Diffstat (limited to 'drivers/usb/serial/cp210x.c')
| -rw-r--r-- | drivers/usb/serial/cp210x.c | 105 |
1 files changed, 75 insertions, 30 deletions
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c index fba1147ed916..8dbf51a43c45 100644 --- a/drivers/usb/serial/cp210x.c +++ b/drivers/usb/serial/cp210x.c @@ -39,6 +39,8 @@ static void cp210x_get_termios(struct tty_struct *, struct usb_serial_port *port); static void cp210x_get_termios_port(struct usb_serial_port *port, unsigned int *cflagp, unsigned int *baudp); +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 int cp210x_tiocmget(struct tty_struct *); @@ -138,6 +140,7 @@ static const struct usb_device_id id_table[] = { { USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */ { USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */ { USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */ + { USB_DEVICE(0x3195, 0xF190) }, /* Link Instruments MSO-19 */ { USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */ { } /* Terminating Entry */ }; @@ -201,6 +204,8 @@ static struct usb_serial_driver cp210x_device = { #define CP210X_EMBED_EVENTS 0x15 #define CP210X_GET_EVENTSTATE 0x16 #define CP210X_SET_CHARS 0x19 +#define CP210X_GET_BAUDRATE 0x1D +#define CP210X_SET_BAUDRATE 0x1E /* CP210X_IFC_ENABLE */ #define UART_ENABLE 0x0001 @@ -360,8 +365,8 @@ static inline int cp210x_set_config_single(struct usb_serial_port *port, * Quantises the baud rate as per AN205 Table 1 */ static unsigned int cp210x_quantise_baudrate(unsigned int baud) { - if (baud <= 56) baud = 0; - else if (baud <= 300) baud = 300; + if (baud <= 300) + baud = 300; else if (baud <= 600) baud = 600; else if (baud <= 1200) baud = 1200; else if (baud <= 1800) baud = 1800; @@ -389,10 +394,10 @@ 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 <= 1053257) baud = 921600; - else if (baud <= 1474560) baud = 1228800; - else if (baud <= 2457600) baud = 1843200; - else baud = 3686400; + else if (baud < 1000000) + baud = 921600; + else if (baud > 2000000) + baud = 2000000; return baud; } @@ -409,13 +414,14 @@ static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port) return result; } - result = usb_serial_generic_open(tty, port); - if (result) - return result; - /* Configure the termios structure */ cp210x_get_termios(tty, port); - return 0; + + /* The baud rate must be initialised on cp2104 */ + if (tty) + cp210x_change_speed(tty, port, NULL); + + return usb_serial_generic_open(tty, port); } static void cp210x_close(struct usb_serial_port *port) @@ -467,10 +473,7 @@ static void cp210x_get_termios_port(struct usb_serial_port *port, dbg("%s - port %d", __func__, port->number); - cp210x_get_config(port, CP210X_GET_BAUDDIV, &baud, 2); - /* Convert to baudrate */ - if (baud) - baud = cp210x_quantise_baudrate((BAUD_RATE_GEN_FREQ + baud/2)/ baud); + cp210x_get_config(port, CP210X_GET_BAUDRATE, &baud, 4); dbg("%s - baud rate = %d", __func__, baud); *baudp = baud; @@ -579,11 +582,64 @@ static void cp210x_get_termios_port(struct usb_serial_port *port, *cflagp = cflag; } +/* + * 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) { unsigned int cflag, old_cflag; - unsigned int baud = 0, bits; + unsigned int bits; unsigned int modem_ctl[4]; dbg("%s - port %d", __func__, port->number); @@ -593,20 +649,9 @@ static void cp210x_set_termios(struct tty_struct *tty, cflag = tty->termios->c_cflag; old_cflag = old_termios->c_cflag; - baud = cp210x_quantise_baudrate(tty_get_baud_rate(tty)); - - /* If the baud rate is to be updated*/ - if (baud != tty_termios_baud_rate(old_termios) && baud != 0) { - dbg("%s - Setting baud rate to %d baud", __func__, - baud); - if (cp210x_set_config_single(port, CP210X_SET_BAUDDIV, - ((BAUD_RATE_GEN_FREQ + baud/2) / baud))) { - dbg("Baud rate requested not supported by device"); - baud = tty_termios_baud_rate(old_termios); - } - } - /* Report back the resulting baud rate */ - tty_encode_baud_rate(tty, baud, baud); + + if (tty->termios->c_ospeed != old_termios->c_ospeed) + cp210x_change_speed(tty, port, old_termios); /* If the number of data bits is to be updated */ if ((cflag & CSIZE) != (old_cflag & CSIZE)) { |