Can't open uart in uClinux with MMU

[Altera_Forum]

Hi~ 

 Right now, I am using uClinux with MMU. My system have 3 uart, however, My system can't see all uarts. He always show 2. Moreover, in ternimal, it shows I have this device, but I can't open it. http://i37.tinypic.com/ifx405.jpg   This picture is my setting about uart http://i36.tinypic.com/244tu0x.jpg  Is there any other select I need to change.  Do I need to change config.c inside arch/nios2/board folder?  Thanks in advance for your help. Tingming

[Altera_Forum]

Hi, 

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

[Altera_Forum]

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.

[Altera_Forum]

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

[Altera_Forum]

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.

[Altera_Forum]

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  --- Quote End ---