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Message-ID: <5697DE45.7000204@collabora.co.uk>
Date: Thu, 14 Jan 2016 17:43:33 +0000
From: Martyn Welch <martyn.welch@...labora.co.uk>
To: Konstantin Shkolnyy <konstantin.shkolnyy@...il.com>,
johan@...nel.org
CC: linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 2/4] USB: serial: cp210x: Switch to new 16-bit register
access functions.
On 02/01/16 03:12, Konstantin Shkolnyy wrote:
> Change to use new 16-bit register access functions instead of
> cp210x_get_config and cp210x_set_config.
>
> Signed-off-by: Konstantin Shkolnyy <konstantin.shkolnyy@...il.com>
> ---
> change in v3: Presented new function addition as a separate patch #1,
> to simplify code review.
>
> drivers/usb/serial/cp210x.c | 80 ++++++++++++++++++---------------------------
> 1 file changed, 31 insertions(+), 49 deletions(-)
>
> diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
> index 324eb7e..7a91c6c 100644
> --- a/drivers/usb/serial/cp210x.c
> +++ b/drivers/usb/serial/cp210x.c
> @@ -588,17 +588,6 @@ static int cp210x_set_config(struct usb_serial_port *port, u8 request,
> }
>
> /*
> - * cp210x_set_config_single
> - * Convenience function for calling cp210x_set_config on single data values
> - * without requiring an integer pointer
> - */
> -static inline int cp210x_set_config_single(struct usb_serial_port *port,
> - u8 request, unsigned int data)
> -{
> - return cp210x_set_config(port, request, &data, 2);
> -}
> -
> -/*
> * Detect CP2108 GET_LINE_CTL bug and activate workaround.
> * Write a known good value 0x800, read it back.
> * If it comes back swapped the bug is detected.
> @@ -607,48 +596,47 @@ static inline int cp210x_set_config_single(struct usb_serial_port *port,
> static int cp210x_detect_swapped_line_ctl(struct usb_serial_port *port)
> {
> struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
> - unsigned int line_ctl_save;
> - unsigned int line_ctl_test;
> + u16 line_ctl_save;
> + u16 line_ctl_test;
> int err;
>
> - err = cp210x_get_config(port, CP210X_GET_LINE_CTL, &line_ctl_save, 2);
> + err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, &line_ctl_save);
> if (err)
> return err;
>
> - line_ctl_test = 0x800;
> - err = cp210x_set_config(port, CP210X_SET_LINE_CTL, &line_ctl_test, 2);
> + err = cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, 0x800);
As mentioned in the comments to the first patch.
> if (err)
> return err;
>
> - err = cp210x_get_config(port, CP210X_GET_LINE_CTL, &line_ctl_test, 2);
> + err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, &line_ctl_test);
> if (err)
> return err;
>
> /* has_swapped_line_ctl is 0 here because port_priv was kzalloced */
> if (line_ctl_test == 8) {
> port_priv->has_swapped_line_ctl = true;
> - line_ctl_save = swab16((u16)line_ctl_save);
> + line_ctl_save = swab16(line_ctl_save);
> }
>
> - return cp210x_set_config(port, CP210X_SET_LINE_CTL, &line_ctl_save, 2);
> + return cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, line_ctl_save);
> }
>
> /*
> - * Must always be called instead of cp210x_get_config(CP210X_GET_LINE_CTL)
> + * Must always be called instead of cp210x_read_u16_reg(CP210X_GET_LINE_CTL)
> * to workaround cp2108 bug and get correct value.
> */
> -static int cp210x_get_line_ctl(struct usb_serial_port *port, unsigned int *ctl)
> +static int cp210x_get_line_ctl(struct usb_serial_port *port, u16 *ctl)
> {
> struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
> int err;
>
> - err = cp210x_get_config(port, CP210X_GET_LINE_CTL, ctl, 2);
> + err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, ctl);
> if (err)
> return err;
>
> /* Workaround swapped bytes in 16-bit value from CP210X_GET_LINE_CTL */
> if (port_priv->has_swapped_line_ctl)
> - *ctl = swab16((u16)(*ctl));
> + *ctl = swab16(*ctl);
>
> return 0;
> }
> @@ -697,14 +685,11 @@ static unsigned int cp210x_quantise_baudrate(unsigned int baud)
>
> static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
> {
> - int result;
> + int err;
>
> - result = cp210x_set_config_single(port, CP210X_IFC_ENABLE,
> - UART_ENABLE);
> - if (result) {
> - dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
> - return result;
> - }
> + err = cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_ENABLE);
> + if (err)
> + return err;
Any reason for dropping the error message?
>
> /* Configure the termios structure */
> cp210x_get_termios(tty, port);
> @@ -718,15 +703,12 @@ static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
>
> static void cp210x_close(struct usb_serial_port *port)
> {
> - unsigned int purge_ctl;
> -
> usb_serial_generic_close(port);
>
> /* Clear both queues; cp2108 needs this to avoid an occasional hang */
> - purge_ctl = PURGE_ALL;
> - cp210x_set_config(port, CP210X_PURGE, &purge_ctl, 2);
> + cp210x_write_u16_reg(port, CP210X_PURGE, PURGE_ALL);
>
> - cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
> + cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_DISABLE);
> }
>
> /*
> @@ -806,7 +788,7 @@ static void cp210x_get_termios_port(struct usb_serial_port *port,
> struct device *dev = &port->dev;
> unsigned int cflag, modem_ctl[4];
> unsigned int baud;
> - unsigned int bits;
> + u16 bits;
>
> cp210x_get_config(port, CP210X_GET_BAUDRATE, &baud, 4);
>
> @@ -839,14 +821,14 @@ static void cp210x_get_termios_port(struct usb_serial_port *port,
> cflag |= CS8;
> bits &= ~BITS_DATA_MASK;
> bits |= BITS_DATA_8;
> - cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
> + cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
> break;
> default:
> dev_dbg(dev, "%s - Unknown number of data bits, using 8\n", __func__);
> cflag |= CS8;
> bits &= ~BITS_DATA_MASK;
> bits |= BITS_DATA_8;
> - cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
> + cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
> break;
> }
>
> @@ -877,7 +859,7 @@ static void cp210x_get_termios_port(struct usb_serial_port *port,
> dev_dbg(dev, "%s - Unknown parity mode, disabling parity\n", __func__);
> cflag &= ~PARENB;
> bits &= ~BITS_PARITY_MASK;
> - cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
> + cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
> break;
> }
>
> @@ -889,7 +871,7 @@ static void cp210x_get_termios_port(struct usb_serial_port *port,
> case BITS_STOP_1_5:
> dev_dbg(dev, "%s - stop bits = 1.5 (not supported, using 1 stop bit)\n", __func__);
> bits &= ~BITS_STOP_MASK;
> - cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
> + cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
> break;
> case BITS_STOP_2:
> dev_dbg(dev, "%s - stop bits = 2\n", __func__);
> @@ -898,7 +880,7 @@ static void cp210x_get_termios_port(struct usb_serial_port *port,
> default:
> dev_dbg(dev, "%s - Unknown number of stop bits, using 1 stop bit\n", __func__);
> bits &= ~BITS_STOP_MASK;
> - cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
> + cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
> break;
> }
>
> @@ -972,7 +954,7 @@ static void cp210x_set_termios(struct tty_struct *tty,
> {
> struct device *dev = &port->dev;
> unsigned int cflag, old_cflag;
> - unsigned int bits;
> + u16 bits;
> unsigned int modem_ctl[4];
>
> cflag = tty->termios.c_cflag;
> @@ -1011,7 +993,7 @@ static void cp210x_set_termios(struct tty_struct *tty,
> bits |= BITS_DATA_8;
> break;
> }
> - if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
> + if (cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
> dev_dbg(dev, "Number of data bits requested not supported by device\n");
> }
>
> @@ -1038,7 +1020,7 @@ static void cp210x_set_termios(struct tty_struct *tty,
> }
> }
> }
> - if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
> + if (cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
> dev_dbg(dev, "Parity mode not supported by device\n");
> }
>
> @@ -1052,7 +1034,7 @@ static void cp210x_set_termios(struct tty_struct *tty,
> bits |= BITS_STOP_1;
> dev_dbg(dev, "%s - stop bits = 1\n", __func__);
> }
> - if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
> + if (cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
> dev_dbg(dev, "Number of stop bits requested not supported by device\n");
> }
>
> @@ -1092,7 +1074,7 @@ static int cp210x_tiocmset(struct tty_struct *tty,
> static int cp210x_tiocmset_port(struct usb_serial_port *port,
> unsigned int set, unsigned int clear)
> {
> - unsigned int control = 0;
> + u16 control = 0;
>
> if (set & TIOCM_RTS) {
> control |= CONTROL_RTS;
> @@ -1113,7 +1095,7 @@ static int cp210x_tiocmset_port(struct usb_serial_port *port,
>
> dev_dbg(&port->dev, "%s - control = 0x%.4x\n", __func__, control);
>
> - return cp210x_set_config(port, CP210X_SET_MHS, &control, 2);
> + return cp210x_write_u16_reg(port, CP210X_SET_MHS, control);
> }
>
> static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
> @@ -1147,7 +1129,7 @@ static int cp210x_tiocmget(struct tty_struct *tty)
> static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
> {
> struct usb_serial_port *port = tty->driver_data;
> - unsigned int state;
> + u16 state;
>
> if (break_state == 0)
> state = BREAK_OFF;
> @@ -1155,7 +1137,7 @@ static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
> state = BREAK_ON;
> dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
> state == BREAK_OFF ? "off" : "on");
> - cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
> + cp210x_write_u16_reg(port, CP210X_SET_BREAK, state);
> }
>
> static int cp210x_port_probe(struct usb_serial_port *port)
>
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