serial: ucc_uart: Remove custom frame size calculation

The number of bits can be calculated using tty_get_frame_size(), no
need for the driver to do it on its own.

Also remove a comment on number of bits that doesn't match the code nor
the comment on ucc_uart_pram's rx_length ("minus 1" part differs). That
comment seems a verbatim copy of that in cpm_uart/cpm_uart_core.c
anyway so perhaps it was just copied over w/o much thinking.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220830084925.5608-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/ucc_uart.c b/drivers/tty/serial/ucc_uart.c
index 0c7768b8e136457d13f998ffc13885753d9a4817..82cf14dd3d433f83a5b07c66b076622614cc4f68 100644 (file)
--- a/drivers/tty/serial/ucc_uart.c
+++ b/drivers/tty/serial/ucc_uart.c
@@ -854,13 +854,6 @@ static void qe_uart_set_termios(struct uart_port *port,
        u16 upsmr = ioread16be(&uccp->upsmr);
        struct ucc_uart_pram __iomem *uccup = qe_port->uccup;
        u16 supsmr = ioread16be(&uccup->supsmr);
-       u8 char_length = 2; /* 1 + CL + PEN + 1 + SL */
-
-       /* Character length programmed into the mode register is the
-        * sum of: 1 start bit, number of data bits, 0 or 1 parity bit,
-        * 1 or 2 stop bits, minus 1.
-        * The value 'bits' counts this for us.
-        */
 
        /* byte size */
        upsmr &= UCC_UART_UPSMR_CL_MASK;
@@ -870,22 +863,18 @@ static void qe_uart_set_termios(struct uart_port *port,
        case CS5:
                upsmr |= UCC_UART_UPSMR_CL_5;
                supsmr |= UCC_UART_SUPSMR_CL_5;
-               char_length += 5;
                break;
        case CS6:
                upsmr |= UCC_UART_UPSMR_CL_6;
                supsmr |= UCC_UART_SUPSMR_CL_6;
-               char_length += 6;
                break;
        case CS7:
                upsmr |= UCC_UART_UPSMR_CL_7;
                supsmr |= UCC_UART_SUPSMR_CL_7;
-               char_length += 7;
                break;
        default:        /* case CS8 */
                upsmr |= UCC_UART_UPSMR_CL_8;
                supsmr |= UCC_UART_SUPSMR_CL_8;
-               char_length += 8;
                break;
        }
 
@@ -893,13 +882,11 @@ static void qe_uart_set_termios(struct uart_port *port,
        if (termios->c_cflag & CSTOPB) {
                upsmr |= UCC_UART_UPSMR_SL;
                supsmr |= UCC_UART_SUPSMR_SL;
-               char_length++;  /* + SL */
        }
 
        if (termios->c_cflag & PARENB) {
                upsmr |= UCC_UART_UPSMR_PEN;
                supsmr |= UCC_UART_SUPSMR_PEN;
-               char_length++;  /* + PEN */
 
                if (!(termios->c_cflag & PARODD)) {
                        upsmr &= ~(UCC_UART_UPSMR_RPM_MASK |
@@ -954,7 +941,7 @@ static void qe_uart_set_termios(struct uart_port *port,
        iowrite16be(upsmr, &uccp->upsmr);
        if (soft_uart) {
                iowrite16be(supsmr, &uccup->supsmr);
-               iowrite8(char_length, &uccup->rx_length);
+               iowrite8(tty_get_frame_size(termios->c_cflag), &uccup->rx_length);
 
                /* Soft-UART requires a 1X multiplier for TX */
                qe_setbrg(qe_port->us_info.rx_clock, baud, 16);