| Message ID | 20190206085612.GA2278@fedora-21-dvm (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] USB: serial: cp210x: add minimun baud rate for CP2105 SCI | expand |
On Wed, Feb 06, 2019 at 09:56:15AM +0100, Johanna Abrahamsson wrote: > From: Johanna Abrahamsson <johanna.abrahamsson@afconsult.com> > > This patch adds minimum baud rate to the cp210x driver. > > According to the datasheet for CP2105, the SCI supports 2400 as the > lowest baud rate. As this is not heeded in the current code, an error > message 'failed set req 0x1e size 4 status: -32' when trying to set a > lower baud rate such as 300. > The other cp210x models to date supports a minimum baud rate of 300. > > Signed-off-by: Johanna Abrahamsson <johanna.abrahamsson@afconsult.com> > --- Thanks for the update. Now applied with a few minor tweaks: > drivers/usb/serial/cp210x.c | 17 ++++++++++++----- > 1 file changed, 12 insertions(+), 5 deletions(-) > > diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c > index 260c875dd263..ceff735e961c 100644 > --- a/drivers/usb/serial/cp210x.c > +++ b/drivers/usb/serial/cp210x.c > @@ -245,6 +245,7 @@ struct cp210x_serial_private { > u8 gpio_input; > #endif > u8 partnum; > + speed_t min_speed; > speed_t max_speed; > bool use_actual_rate; > }; > @@ -1078,8 +1079,6 @@ static speed_t cp210x_get_actual_rate(struct usb_serial *serial, speed_t baud) > unsigned int prescale = 1; > unsigned int div; > > - baud = clamp(baud, 300u, priv->max_speed); priv is now unused in this function and thus triggered a compilation warning. I dropped priv along with the serial pointer. > - > if (baud <= 365) > prescale = 4; > > @@ -1122,7 +1121,7 @@ static void cp210x_change_speed(struct tty_struct *tty, > struct cp210x_serial_private *priv = usb_get_serial_data(serial); > u32 baud; > > - baud = tty->termios.c_ospeed; > + baud = clamp(tty->termios.c_ospeed, priv->min_speed, priv->max_speed); I moved this clamp after the comment since this construct now makes sure we honour max_speed. > /* > * This maps the requested rate to the actual rate, a valid rate on > @@ -1134,8 +1133,6 @@ static void cp210x_change_speed(struct tty_struct *tty, > baud = cp210x_get_actual_rate(serial, baud); > else if (baud < 1000000) > baud = cp210x_get_an205_rate(baud); > - else if (baud > priv->max_speed) > - baud = priv->max_speed; > > dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud); > if (cp210x_write_u32_reg(port, CP210X_SET_BAUDRATE, baud)) { > @@ -1797,28 +1794,35 @@ static void cp210x_init_max_speed(struct usb_serial *serial) > { > struct cp210x_serial_private *priv = usb_get_serial_data(serial); > bool use_actual_rate = false; > + speed_t min; And I initialised min to 300 here which allows most initialisations below to be removed. > speed_t max; > > switch (priv->partnum) { > case CP210X_PARTNUM_CP2101: > + min = 300; > max = 921600; > break; > case CP210X_PARTNUM_CP2102: > case CP210X_PARTNUM_CP2103: > + min = 300; > max = 1000000; > break; > case CP210X_PARTNUM_CP2104: > use_actual_rate = true; > + min = 300; > max = 2000000; > break; > case CP210X_PARTNUM_CP2108: > + min = 300; > max = 2000000; > break; > case CP210X_PARTNUM_CP2105: > if (cp210x_interface_num(serial) == 0) { > use_actual_rate = true; > + min = 300; > max = 2000000; /* ECI */ > } else { > + min = 2400; > max = 921600; /* SCI */ > } > break; > @@ -1826,13 +1830,16 @@ static void cp210x_init_max_speed(struct usb_serial *serial) > case CP210X_PARTNUM_CP2102N_QFN24: > case CP210X_PARTNUM_CP2102N_QFN20: > use_actual_rate = true; > + min = 300; > max = 3000000; > break; > default: > + min = 300; > max = 2000000; > break; > } > > + priv->min_speed = min; > priv->max_speed = max; > priv->use_actual_rate = use_actual_rate; > } Thanks, Johan
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c index 260c875dd263..ceff735e961c 100644 --- a/drivers/usb/serial/cp210x.c +++ b/drivers/usb/serial/cp210x.c @@ -245,6 +245,7 @@ struct cp210x_serial_private { u8 gpio_input; #endif u8 partnum; + speed_t min_speed; speed_t max_speed; bool use_actual_rate; }; @@ -1078,8 +1079,6 @@ static speed_t cp210x_get_actual_rate(struct usb_serial *serial, speed_t baud) unsigned int prescale = 1; unsigned int div; - baud = clamp(baud, 300u, priv->max_speed); - if (baud <= 365) prescale = 4; @@ -1122,7 +1121,7 @@ static void cp210x_change_speed(struct tty_struct *tty, struct cp210x_serial_private *priv = usb_get_serial_data(serial); u32 baud; - baud = tty->termios.c_ospeed; + baud = clamp(tty->termios.c_ospeed, priv->min_speed, priv->max_speed); /* * This maps the requested rate to the actual rate, a valid rate on @@ -1134,8 +1133,6 @@ static void cp210x_change_speed(struct tty_struct *tty, baud = cp210x_get_actual_rate(serial, baud); else if (baud < 1000000) baud = cp210x_get_an205_rate(baud); - else if (baud > priv->max_speed) - baud = priv->max_speed; dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud); if (cp210x_write_u32_reg(port, CP210X_SET_BAUDRATE, baud)) { @@ -1797,28 +1794,35 @@ static void cp210x_init_max_speed(struct usb_serial *serial) { struct cp210x_serial_private *priv = usb_get_serial_data(serial); bool use_actual_rate = false; + speed_t min; speed_t max; switch (priv->partnum) { case CP210X_PARTNUM_CP2101: + min = 300; max = 921600; break; case CP210X_PARTNUM_CP2102: case CP210X_PARTNUM_CP2103: + min = 300; max = 1000000; break; case CP210X_PARTNUM_CP2104: use_actual_rate = true; + min = 300; max = 2000000; break; case CP210X_PARTNUM_CP2108: + min = 300; max = 2000000; break; case CP210X_PARTNUM_CP2105: if (cp210x_interface_num(serial) == 0) { use_actual_rate = true; + min = 300; max = 2000000; /* ECI */ } else { + min = 2400; max = 921600; /* SCI */ } break; @@ -1826,13 +1830,16 @@ static void cp210x_init_max_speed(struct usb_serial *serial) case CP210X_PARTNUM_CP2102N_QFN24: case CP210X_PARTNUM_CP2102N_QFN20: use_actual_rate = true; + min = 300; max = 3000000; break; default: + min = 300; max = 2000000; break; } + priv->min_speed = min; priv->max_speed = max; priv->use_actual_rate = use_actual_rate; }