UART波特率修改问题

Chip Platform Rockchip
1

本帖最后由 tigerlh 于 2020-9-4 10:31 编辑

日志输出的串口ttyS0波特率参照文档修改成了115200；
但是，其它的串口试了多种方法都无法修改波特率，使用过的方法有：

  1. stty -F /dev/ttyS3 speed 115200
  2. dtsi文件修改：
    uart3: serial@ff0d0000 {
    compatible = “rockchip,rk3308-uart”, “snps,dw-apb-uart”;
    reg = <0x0 0xff0d0000 0x0 0x100>;
    interrupts = <GIC_SPI 21 IRQ_TYPE_LEVEL_HIGH>;
    clocks = <&cru SCLK_UART3>, <&cru PCLK_UART3>;
    clock-names = “baudclk”, “apb_pclk”;
    baudrate = <115200>;
    speed = <115200>;
    = <115200>;
    reg-shift = <2>;
    reg-io-width = <4>;
    dmas = <&dmac0 10>, <&dmac0 11>;
    dma-names = “tx”, “rx”;
    pinctrl-names = “default”;
    pinctrl-0 = <&uart3_xfer>;
    status = “okay”;
    };
    之后用stty -F /dev/ttyS3查看波特率依然为9600：
    speed 9600 baud; line = 0;
    intr = ; quit = ; erase = ; kill = ; eof = ;
    start = ; stop = ; susp = ; rprnt = ;
    werase = ; lnext = ; discard = ; min = 0; time = 0;
    -brkint -icrnl -imaxbel
    -opost -onlcr
    -isig -icanon -iexten -echo -echoe -echok -echoctl -echoke

请指教

2

补充下, 如下将9600改为115200后只有Uart0有效，其它端口依然是9600
int uart_register_driver(struct uart_driver *drv)
{
struct tty_driver *normal;
int i, retval;

BUG_ON(drv->state);

/*
 * Maybe we should be using a slab cache for this, especially if
 * we have a large number of ports to handle.
 */
drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
if (!drv->state)
	goto out;

normal = alloc_tty_driver(drv->nr);
if (!normal)
	goto out_kfree;

drv->tty_driver = normal;

normal->driver_name	= drv->driver_name;
normal->name		= drv->dev_name;
normal->major		= drv->major;
normal->minor_start	= drv->minor;
normal->type		= TTY_DRIVER_TYPE_SERIAL;
normal->subtype		= SERIAL_TYPE_NORMAL;
normal->init_termios	= tty_std_termios;
normal->init_termios.c_cflag = B115200 | CS8 | CREAD | HUPCL | CLOCAL;
normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 115200;
3

多试几遍或者等会再查看

ttys3.png
ttys3.png633×297 9.13 KB