From ed921771ffb65ce1f65d746fe8f88c0e0a829d76 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 16 Nov 2020 17:18:25 +0100 Subject: USB: serial: cp210x: refactor flow-control handling Add a helper function to be used to configure flow control. The flow-control code was the last caller that relied on the memset-on-failure behaviour of cp210x_read_reg_block(), which we can now drop in favour of bailing out on errors when retrieving the flow-control settings. This should also simplify adding support for software flow control. Signed-off-by: Johan Hovold --- drivers/usb/serial/cp210x.c | 97 ++++++++++++++++++++++----------------------- 1 file changed, 47 insertions(+), 50 deletions(-) (limited to 'drivers/usb/serial/cp210x.c') diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c index 04d2b15ceded..c77fd09b91ce 100644 --- a/drivers/usb/serial/cp210x.c +++ b/drivers/usb/serial/cp210x.c @@ -555,14 +555,8 @@ static int cp210x_read_reg_block(struct usb_serial_port *port, u8 req, int result; dmabuf = kmalloc(bufsize, GFP_KERNEL); - if (!dmabuf) { - /* - * FIXME Some callers don't bother to check for error, - * at least give them consistent junk until they are fixed - */ - memset(buf, 0, bufsize); + if (!dmabuf) return -ENOMEM; - } result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0), req, REQTYPE_INTERFACE_TO_HOST, 0, @@ -576,12 +570,6 @@ static int cp210x_read_reg_block(struct usb_serial_port *port, u8 req, req, bufsize, result); if (result >= 0) result = -EIO; - - /* - * FIXME Some callers don't bother to check for error, - * at least give them consistent junk until they are fixed - */ - memset(buf, 0, bufsize); } kfree(dmabuf); @@ -1095,11 +1083,55 @@ static bool cp210x_termios_change(const struct ktermios *a, const struct ktermio return tty_termios_hw_change(a, b) || iflag_change; } +static void cp210x_set_flow_control(struct tty_struct *tty, + struct usb_serial_port *port, struct ktermios *old_termios) +{ + struct cp210x_flow_ctl flow_ctl; + u32 flow_repl; + u32 ctl_hs; + int ret; + + if (old_termios && C_CRTSCTS(tty) == (old_termios->c_cflag & CRTSCTS)) + return; + + ret = cp210x_read_reg_block(port, CP210X_GET_FLOW, &flow_ctl, + sizeof(flow_ctl)); + if (ret) + return; + + ctl_hs = le32_to_cpu(flow_ctl.ulControlHandshake); + flow_repl = le32_to_cpu(flow_ctl.ulFlowReplace); + + ctl_hs &= ~CP210X_SERIAL_DSR_HANDSHAKE; + ctl_hs &= ~CP210X_SERIAL_DCD_HANDSHAKE; + ctl_hs &= ~CP210X_SERIAL_DSR_SENSITIVITY; + ctl_hs &= ~CP210X_SERIAL_DTR_MASK; + ctl_hs |= CP210X_SERIAL_DTR_SHIFT(CP210X_SERIAL_DTR_ACTIVE); + + if (C_CRTSCTS(tty)) { + ctl_hs |= CP210X_SERIAL_CTS_HANDSHAKE; + flow_repl &= ~CP210X_SERIAL_RTS_MASK; + flow_repl |= CP210X_SERIAL_RTS_SHIFT(CP210X_SERIAL_RTS_FLOW_CTL); + } else { + ctl_hs &= ~CP210X_SERIAL_CTS_HANDSHAKE; + flow_repl &= ~CP210X_SERIAL_RTS_MASK; + flow_repl |= CP210X_SERIAL_RTS_SHIFT(CP210X_SERIAL_RTS_ACTIVE); + } + + dev_dbg(&port->dev, "%s - 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)); +} + static void cp210x_set_termios(struct tty_struct *tty, struct usb_serial_port *port, struct ktermios *old_termios) { struct cp210x_serial_private *priv = usb_get_serial_data(port->serial); - struct device *dev = &port->dev; u16 bits; int ret; @@ -1156,42 +1188,7 @@ static void cp210x_set_termios(struct tty_struct *tty, if (ret) dev_err(&port->dev, "failed to set line control: %d\n", ret); - if (!old_termios || C_CRTSCTS(tty) != (old_termios->c_cflag & CRTSCTS)) { - struct cp210x_flow_ctl flow_ctl; - u32 ctl_hs; - u32 flow_repl; - - 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); - - ctl_hs &= ~CP210X_SERIAL_DSR_HANDSHAKE; - ctl_hs &= ~CP210X_SERIAL_DCD_HANDSHAKE; - ctl_hs &= ~CP210X_SERIAL_DSR_SENSITIVITY; - ctl_hs &= ~CP210X_SERIAL_DTR_MASK; - ctl_hs |= CP210X_SERIAL_DTR_SHIFT(CP210X_SERIAL_DTR_ACTIVE); - if (C_CRTSCTS(tty)) { - ctl_hs |= CP210X_SERIAL_CTS_HANDSHAKE; - - flow_repl &= ~CP210X_SERIAL_RTS_MASK; - flow_repl |= CP210X_SERIAL_RTS_SHIFT( - CP210X_SERIAL_RTS_FLOW_CTL); - } else { - ctl_hs &= ~CP210X_SERIAL_CTS_HANDSHAKE; - - flow_repl &= ~CP210X_SERIAL_RTS_MASK; - flow_repl |= CP210X_SERIAL_RTS_SHIFT( - CP210X_SERIAL_RTS_ACTIVE); - } - - dev_dbg(dev, "%s - 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)); - } + cp210x_set_flow_control(tty, port, old_termios); /* * Enable event-insertion mode only if input parity checking is -- cgit v1.2.3