From 9034389cd81681b4f0123173eb836624199209c7 Mon Sep 17 00:00:00 2001 From: Konstantin Shkolnyy Date: Wed, 4 May 2016 16:57:02 -0500 Subject: USB: serial: cp210x: get rid of magic numbers in CRTSCTS flag code Replaced magic numbers used in the CRTSCTS flag code with symbolic names from the chip specification. Signed-off-by: Konstantin Shkolnyy Signed-off-by: Johan Hovold --- drivers/usb/serial/cp210x.c | 109 ++++++++++++++++++++++++++++++++++---------- 1 file changed, 84 insertions(+), 25 deletions(-) (limited to 'drivers/usb/serial/cp210x.c') diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c index fef7a512bff4..a33a4265125d 100644 --- a/drivers/usb/serial/cp210x.c +++ b/drivers/usb/serial/cp210x.c @@ -327,6 +327,42 @@ struct cp210x_comm_status { */ #define PURGE_ALL 0x000f +/* CP210X_GET_FLOW/CP210X_SET_FLOW read/write these 0x10 bytes */ +struct cp210x_flow_ctl { + __le32 ulControlHandshake; + __le32 ulFlowReplace; + __le32 ulXonLimit; + __le32 ulXoffLimit; +} __packed; + +/* cp210x_flow_ctl::ulControlHandshake */ +#define CP210X_SERIAL_DTR_MASK GENMASK(1, 0) +#define CP210X_SERIAL_DTR_SHIFT(_mode) (_mode) +#define CP210X_SERIAL_CTS_HANDSHAKE BIT(3) +#define CP210X_SERIAL_DSR_HANDSHAKE BIT(4) +#define CP210X_SERIAL_DCD_HANDSHAKE BIT(5) +#define CP210X_SERIAL_DSR_SENSITIVITY BIT(6) + +/* values for cp210x_flow_ctl::ulControlHandshake::CP210X_SERIAL_DTR_MASK */ +#define CP210X_SERIAL_DTR_INACTIVE 0 +#define CP210X_SERIAL_DTR_ACTIVE 1 +#define CP210X_SERIAL_DTR_FLOW_CTL 2 + +/* cp210x_flow_ctl::ulFlowReplace */ +#define CP210X_SERIAL_AUTO_TRANSMIT BIT(0) +#define CP210X_SERIAL_AUTO_RECEIVE BIT(1) +#define CP210X_SERIAL_ERROR_CHAR BIT(2) +#define CP210X_SERIAL_NULL_STRIPPING BIT(3) +#define CP210X_SERIAL_BREAK_CHAR BIT(4) +#define CP210X_SERIAL_RTS_MASK GENMASK(7, 6) +#define CP210X_SERIAL_RTS_SHIFT(_mode) (_mode << 6) +#define CP210X_SERIAL_XOFF_CONTINUE BIT(31) + +/* values for cp210x_flow_ctl::ulFlowReplace::CP210X_SERIAL_RTS_MASK */ +#define CP210X_SERIAL_RTS_INACTIVE 0 +#define CP210X_SERIAL_RTS_ACTIVE 1 +#define CP210X_SERIAL_RTS_FLOW_CTL 2 + /* * Reads a variable-sized block of CP210X_ registers, identified by req. * Returns data into buf in native USB byte order. @@ -694,9 +730,10 @@ static void cp210x_get_termios_port(struct usb_serial_port *port, { struct device *dev = &port->dev; unsigned int cflag; - u8 modem_ctl[16]; + struct cp210x_flow_ctl flow_ctl; u32 baud; u16 bits; + u32 ctl_hs; cp210x_read_u32_reg(port, CP210X_GET_BAUDRATE, &baud); @@ -792,9 +829,10 @@ static void cp210x_get_termios_port(struct usb_serial_port *port, break; } - cp210x_read_reg_block(port, CP210X_GET_FLOW, modem_ctl, - sizeof(modem_ctl)); - if (modem_ctl[0] & 0x08) { + cp210x_read_reg_block(port, CP210X_GET_FLOW, &flow_ctl, + sizeof(flow_ctl)); + ctl_hs = le32_to_cpu(flow_ctl.ulControlHandshake); + if (ctl_hs & CP210X_SERIAL_CTS_HANDSHAKE) { dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__); cflag |= CRTSCTS; } else { @@ -863,7 +901,6 @@ static void cp210x_set_termios(struct tty_struct *tty, struct device *dev = &port->dev; unsigned int cflag, old_cflag; u16 bits; - u8 modem_ctl[16]; cflag = tty->termios.c_cflag; old_cflag = old_termios->c_cflag; @@ -947,34 +984,56 @@ static void cp210x_set_termios(struct tty_struct *tty, } if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) { + struct cp210x_flow_ctl flow_ctl; + u32 ctl_hs; + u32 flow_repl; - /* Only bytes 0, 4 and 7 out of first 8 have functional bits */ - - cp210x_read_reg_block(port, CP210X_GET_FLOW, modem_ctl, - sizeof(modem_ctl)); - dev_dbg(dev, "%s - read modem controls = %02x .. .. .. %02x .. .. %02x\n", - __func__, modem_ctl[0], modem_ctl[4], modem_ctl[7]); + cp210x_read_reg_block(port, CP210X_GET_FLOW, &flow_ctl, + sizeof(flow_ctl)); + ctl_hs = le32_to_cpu(flow_ctl.ulControlHandshake); + flow_repl = le32_to_cpu(flow_ctl.ulFlowReplace); + dev_dbg(dev, "%s - read ulControlHandshake=0x%08x, ulFlowReplace=0x%08x\n", + __func__, ctl_hs, flow_repl); if (cflag & CRTSCTS) { - modem_ctl[0] &= ~0x7B; - modem_ctl[0] |= 0x09; - modem_ctl[4] = 0x80; - /* FIXME - why clear reserved bits just read? */ - modem_ctl[5] = 0; - modem_ctl[6] = 0; - modem_ctl[7] = 0; + ctl_hs &= ~(CP210X_SERIAL_DTR_MASK | + CP210X_SERIAL_CTS_HANDSHAKE | + CP210X_SERIAL_DSR_HANDSHAKE | + CP210X_SERIAL_DCD_HANDSHAKE | + CP210X_SERIAL_DSR_SENSITIVITY); + ctl_hs |= CP210X_SERIAL_DTR_SHIFT( + CP210X_SERIAL_DTR_ACTIVE); + ctl_hs |= CP210X_SERIAL_CTS_HANDSHAKE; + /* + * FIXME: Why clear bits unrelated to flow control. + * Why clear CP210X_SERIAL_XOFF_CONTINUE which is + * never set + */ + flow_repl = 0; + flow_repl |= CP210X_SERIAL_RTS_SHIFT( + CP210X_SERIAL_RTS_FLOW_CTL); dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__); } else { - modem_ctl[0] &= ~0x7B; - modem_ctl[0] |= 0x01; - modem_ctl[4] = 0x40; + ctl_hs &= ~(CP210X_SERIAL_DTR_MASK | + CP210X_SERIAL_CTS_HANDSHAKE | + CP210X_SERIAL_DSR_HANDSHAKE | + CP210X_SERIAL_DCD_HANDSHAKE | + CP210X_SERIAL_DSR_SENSITIVITY); + ctl_hs |= CP210X_SERIAL_DTR_SHIFT( + CP210X_SERIAL_DTR_ACTIVE); + /* FIXME: Why clear bits unrelated to flow control */ + flow_repl &= 0xffffff00; + flow_repl |= CP210X_SERIAL_RTS_SHIFT( + CP210X_SERIAL_RTS_ACTIVE); dev_dbg(dev, "%s - flow control = NONE\n", __func__); } - dev_dbg(dev, "%s - write modem controls = %02x .. .. .. %02x .. .. %02x\n", - __func__, modem_ctl[0], modem_ctl[4], modem_ctl[7]); - cp210x_write_reg_block(port, CP210X_SET_FLOW, modem_ctl, - sizeof(modem_ctl)); + dev_dbg(dev, "%s - write ulControlHandshake=0x%08x, ulFlowReplace=0x%08x\n", + __func__, ctl_hs, flow_repl); + flow_ctl.ulControlHandshake = cpu_to_le32(ctl_hs); + flow_ctl.ulFlowReplace = cpu_to_le32(flow_repl); + cp210x_write_reg_block(port, CP210X_SET_FLOW, &flow_ctl, + sizeof(flow_ctl)); } } -- cgit v1.2.3