I couldn't get the echo > /dev/xxx to work. I had to write a small app that opened the device and write and read characters for testing.
Start there and you may find it is actually working. JB On Wed, Jun 9, 2010 at 8:37 AM, Martyn Welch <martyn.we...@ge.com> wrote: > Hi All, > > I'm attempting to get an SCC port on an MPC8270 working with Linux. I'm > not overly familiar with the CPM and am having a bit of trouble. > > Linux is booting natively on the 8270. I have access to the 8270 via a > set of PCI windows from a second core (includes one setup over the main > memory and one over the IMMR) and SMC1 is up and working with a console. > > The SCCs seem to be detected correctly at boot: > > f011a80.serial: ttyCPM0 at MMIO 0xc3014a80 (irq = 16) is a CPM UART > f011a00.serial: ttyCPM1 at MMIO 0xc3018a00 (irq = 40) is a CPM UART > f011a20.serial: ttyCPM2 at MMIO 0xc3020a20 (irq = 41) is a CPM UART > f011a40.serial: ttyCPM3 at MMIO 0xc3028a40 (irq = 42) is a CPM UART > > With the DTS reading: > > smc1: ser...@11a80 { > device_type = "serial"; > compatible = "fsl,mpc8270-smc-uart", > "fsl,cpm2-smc-uart"; > reg = <0x11a80 0x20 0x87fc 2>; > interrupts = <4 8>; > interrupt-parent = <&PIC>; > fsl,cpm-brg = <7>; > fsl,cpm-command = <0x1d000000>; > }; > > scc1: ser...@11a00 { > device_type = "serial"; > compatible = "fsl,mpc8270-scc-uart", > "fsl,cpm2-scc-uart"; > reg = <0x11a00 0x20 0x8000 0x100>; > interrupts = <40 8>; > interrupt-parent = <&PIC>; > fsl,cpm-brg = <3>; > fsl,cpm-command = <0x800000>; > }; > > scc2: ser...@11a20 { > device_type = "serial"; > compatible = "fsl,mpc8270-scc-uart", > "fsl,cpm2-scc-uart"; > reg = <0x11a20 0x20 0x8100 0x100>; > interrupts = <41 8>; > interrupt-parent = <&PIC>; > fsl,cpm-brg = <6>; > fsl,cpm-command = <0x4a00000>; > }; > > scc3: ser...@11a40 { > device_type = "serial"; > compatible = "fsl,mpc8270-scc-uart", > "fsl,cpm2-scc-uart"; > reg = <0x11a40 0x20 0x8200 0x100>; > interrupts = <42 8>; > interrupt-parent = <&PIC>; > fsl,cpm-brg = <1>; > fsl,cpm-command = <0x8c00000>; > }; > > I believe that I have the pins setup correctly and the BRGs connected > correctly in the setup_arch function. > > At the moment I have SCC3 wired out. If I attempt to echo data out of > the SCC (echo "Hello" > /dev/ttyCPM3) I get the prompt sits waiting. > Rebooting and turning on the debug yields the following output on the > console (but nothing out of the SCC port): > > CPM uart[3]:startup > Interrupt attached > CPM uart[3]:set_termios > CPM uart[3]:start tx > CPM uart[3]:stop tx > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:stop rx > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:shutdown > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > CPM uart[3]:tx_empty: 0 > ... > > > It seemed to be waiting for ready bit of the Transmit Buffer Descriptor > to be cleared (which it never seems to be), prodding this bit through > the pci window did cause the process to continue, no data out but I did > get back to the prompt on the console. > > I'm sure I'm just missing something really basic - can anyone enlighten me? > > Martyn > > -- > Martyn Welch (Principal Software Engineer) | Registered in England and > GE Intelligent Platforms | Wales (3828642) at 100 > T +44(0)127322748 | Barbirolli Square, > Manchester, > E martyn.we...@ge.com | M2 3AB VAT:GB 927559189 > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev > -- Jim Black Senior Software Engineer Aztek Networks, Inc. 2477 55th Street, Suite 202 Boulder, CO 80301 www.azteknetworks.com _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev