Can't open uart in uClinux with MMU

Hi,

Maybe you need /dev/ttyS2, /dev/ttyS3...:D

Kazu

Hi Kazu:

I don't get it, why I need /dev/ttyS2 and S3?

I have 3 uart in my system, but it only show 2.

And I can't open (ttyS0 and ttyS1) in software.

Thank you very much for reply me.

Hi,

--- Quote Start ---

I don't get it, why I need /dev/ttyS2 and S3?

I have 3 uart in my system, but it only show 2.

And I can't open (ttyS0 and ttyS1) in software.

--- Quote End ---

Please check that your UART names are well-defined in the file 'nios2-linux/linux-2.6/arch/nios2/kernel/config.c', and if not, please modify it. In default, those must be 'UART0. 'UART1', 'UART2' and 'UART3'.

/*
 *    Altera UART
 */
static struct altera_uart_platform_uart nios2_uart_platform = {# if defined(UART0_BASE) || defined(UART_BASE)
 # ifdef UART0_BASE
    {
     .mapbase = UART0_BASE,
     .irq = UART0_IRQ,
     .uartclk = UART0_FREQ,
     },
 # else
    {
     .mapbase = UART_BASE,
     .irq = UART_IRQ,
     .uartclk = UART_FREQ,
     },
 # endif# endif# ifdef UART1_BASE
    {
     .mapbase = UART1_BASE,
     .irq = UART1_IRQ,
     .uartclk = UART1_FREQ,
     },# endif# ifdef UART2_BASE
    {
     .mapbase = UART2_BASE,
     .irq = UART2_IRQ,
     .uartclk = UART2_FREQ,
     },# endif# ifdef UART3_BASE
    {
     .mapbase = UART3_BASE,
     .irq = UART3_IRQ,
     .uartclk = UART3_FREQ,
     },# endif
    {},
};

And UART devices are probed in the function 'altera_uart_probe' of the file 'nios2-linux/linux-2.6/drivers/serial/altuart.c'.

static int __devinit altera_uart_probe(struct platform_device *pdev)
{
    struct altera_uart_platform_uart *platp = pdev->dev.platform_data;
    struct uart_port *port;
    int i;
    for (i = 0;
         ((i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS) && (platp.mapbase));
         i++) {
        port = &altera_uart_ports.port;
        port->line = i;
        port->type = PORT_ALTERA_UART;
        port->mapbase = platp.mapbase;
        port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
        port->iotype = SERIAL_IO_MEM;
        port->irq = platp.irq;
        port->uartclk = platp.uartclk;
        port->ops = &altera_uart_ops;
        port->flags = ASYNC_BOOT_AUTOCONF;
        uart_add_one_port(&altera_uart_driver, port);
    }
    return 0;
}

Please debug it by 'printk', if necessry. Anyway you must distinguish your UART devices by major and minor numbers, so you need /dev/ttyS2 and /dev/ttyS3 after your 4 UARTs are probed successfully.

Kazu

Hi Kazu~

Thank you very much!

My UART (S0 S1)can work already.

Now, I am trying to make S2 work.

I use mknod /dev/ttyS2 c 4 66, and my ttyS2 can work now

I didn't change config.c files, so I can't use my UART.

Thank you again for solving my problems.

TingMing.

Hi,

Thanks in advance if you can shine light to the UART problem I am having. Like the problem you are having, I can't open the port or communicate to it, and I have name all my port with 'UART0. 'UART1', 'UART2' and 'UART3' in my QSYS and my device tree DTS file. The uClinux ver 3.1 boot up detect there is a UART with correct base address and irq:

ttyAL0 at MMIO 0x8100160 (irq =5) is a Altera UART

ttyAL1 at MMIO 0x8100180 (irq =6) is a Altera UART

ttyAL2 at MMIO 0x8100200 (irq =7) is a Altera UART

ttyAL3 at MMIO 0x8100220 (irq =8) is a Altera UART

ttyAL4 at MMIO 0x8100240 (irq =9) is a Altera UART

ttyAL5 at MMIO 0x8100260 (irq =10) is a Altera UART

The /dev have ttyAL0 in it, but not none of the other ports. I'm able to open and communicate with ttyAL0, but none other port. Is there something I have to do specially for the device tree or driver I have to change? I did look at the altera_uart.c and can't figure out the problem.

--- Quote Start ---

Hi,

Please check that your UART names are well-defined in the file 'nios2-linux/linux-2.6/arch/nios2/kernel/config.c', and if not, please modify it. In default, those must be 'UART0. 'UART1', 'UART2' and 'UART3'.

/*
 *    Altera UART
 */
static struct altera_uart_platform_uart nios2_uart_platform = {# if defined(UART0_BASE) || defined(UART_BASE)
 # ifdef UART0_BASE
    {
     .mapbase = UART0_BASE,
     .irq = UART0_IRQ,
     .uartclk = UART0_FREQ,
     },
 # else
    {
     .mapbase = UART_BASE,
     .irq = UART_IRQ,
     .uartclk = UART_FREQ,
     },
 # endif# endif# ifdef UART1_BASE
    {
     .mapbase = UART1_BASE,
     .irq = UART1_IRQ,
     .uartclk = UART1_FREQ,
     },# endif# ifdef UART2_BASE
    {
     .mapbase = UART2_BASE,
     .irq = UART2_IRQ,
     .uartclk = UART2_FREQ,
     },# endif# ifdef UART3_BASE
    {
     .mapbase = UART3_BASE,
     .irq = UART3_IRQ,
     .uartclk = UART3_FREQ,
     },# endif
    {},
};

And UART devices are probed in the function 'altera_uart_probe' of the file 'nios2-linux/linux-2.6/drivers/serial/altuart.c'.

static int __devinit altera_uart_probe(struct platform_device *pdev)
{
    struct altera_uart_platform_uart *platp = pdev->dev.platform_data;
    struct uart_port *port;
    int i;
    for (i = 0;
         ((i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS) && (platp.mapbase));
         i++) {
        port = &altera_uart_ports.port;
        port->line = i;
        port->type = PORT_ALTERA_UART;
        port->mapbase = platp.mapbase;
        port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
        port->iotype = SERIAL_IO_MEM;
        port->irq = platp.irq;
        port->uartclk = platp.uartclk;
        port->ops = &altera_uart_ops;
        port->flags = ASYNC_BOOT_AUTOCONF;
        uart_add_one_port(&altera_uart_driver, port);
    }
    return 0;
}

Please debug it by 'printk', if necessry. Anyway you must distinguish your UART devices by major and minor numbers, so you need /dev/ttyS2 and /dev/ttyS3 after your 4 UARTs are probed successfully.

Kazu

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