diff options
| author | Yu Tu <yu.tu@amlogic.com> | 2022-04-07 11:13:53 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-15 12:28:10 +0300 |
| commit | 368ab68b18de104719f386a5cfe3595673cc96de (patch) | |
| tree | a576769b69462d0428bb1bf09eb368c23de13511 | |
| parent | 19401e9755313ba681e9c8f41e8c176cd95663bb (diff) | |
| download | linux-368ab68b18de104719f386a5cfe3595673cc96de.tar.xz | |
tty: serial: meson: Use DIV_ROUND_CLOSEST to calculate baud rates
Due to chip process differences, chip designers recommend using baud
rates as close to and larger as possible in order to reduce clock
errors.
Signed-off-by: Yu Tu <yu.tu@amlogic.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20220407081355.13602-2-yu.tu@amlogic.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/meson_uart.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c index 2bf1c57e0981..8e59624935af 100644 --- a/drivers/tty/serial/meson_uart.c +++ b/drivers/tty/serial/meson_uart.c @@ -299,10 +299,10 @@ static void meson_uart_change_speed(struct uart_port *port, unsigned long baud) cpu_relax(); if (port->uartclk == 24000000) { - val = ((port->uartclk / 3) / baud) - 1; + val = DIV_ROUND_CLOSEST(port->uartclk / 3, baud) - 1; val |= AML_UART_BAUD_XTAL; } else { - val = ((port->uartclk * 10 / (baud * 4) + 5) / 10) - 1; + val = DIV_ROUND_CLOSEST(port->uartclk / 4, baud) - 1; } val |= AML_UART_BAUD_USE; writel(val, port->membase + AML_UART_REG5); |