Re: [Xenomai] Flexcan RT driver registration failed

[Wolfgang Grandegger <wg@grandegger.com>]

On Tue, 05 May 2015 13:22:45 +0200, Wolfgang Netbal
<wolfgang.netbal@sigmatek.at> wrote:
> Dear All,
> 
> I have a custom board with an imx6dl using freescale yocto 3.10.53 with 
> Xenomai 2.6.4.
> The probe function works fine while booting the kernel
> 
> RT-Socket-CAN 0.90.2 - (C) 2006 RT-Socket-CAN Development Team
> rtcan: registered rtcan0
> flexcan 2090000.can: RTCAN device registered (reg_base=d0c00000, 
> irq=142, clock=66000000)
> rtcan: registered rtcan1
> flexcan 2094000.can: RTCAN device registered (reg_base=d0c08000, 
> irq=143, clock=66000000)
> 
> After Linux started I call the function flexcan_mode_start() and get the

> following message and CAN connections doesn't work.
> 
> rtcan0: Failed to softreset can module (mcr=0x5b80000f)
> 
> I have a working configuration for this board using Kernel 3.0.43 and 
> Xenomai 2.6.2.1
> 
> RT-Socket-CAN 0.90.2 - (C) 2006 RT-Socket-CAN Development Team
> flexcan netdevice driver
> rtcan: registered rtcan0
> flexcan imx6q-flexcan.0: RTCAN device registered (reg_base=e0968000, 
> irq=142, clock=30000000)
> rtcan: registered rtcan1
> flexcan imx6q-flexcan.1: RTCAN device registered (reg_base=e0970000, 
> irq=143, clock=30000000)
> ...
> rtcan0: writing ctrl=0x03292005
> 
> It seems that the clock is the difference so I checked the values of 
> register CCM_CCGR0
> 3.0.43 address 0x20C4068 is set to 0x7fc03f
> 3.10.53 address 0x20C4068 is set to 0x4cc00f
> 
> so on kernel 3.10.53 are the serial clocks for can disabled.
> 
> If anyone has a hint for me how to activate the serial clock in register

> CCM_CCGR0 and change the clock to 30000000 that would be great.

Have a look into the directory "arch/arm/boot/dts" of a recent kernel tree
and execute therein "grep LEXCAN[12] *.dts*". There are various boards
setting the pins you mention below. Maybe you find some matching hardware.

> Here is the part of the devicetree used to configure flexcan.
> 
> 
> #include "imx6dl.dtsi"
> 
> / {
> 
> };
> 
> /*
>   * PAD settings
>   */
> &iomuxc {
>      flexcan1 {
>          pinctrl_flexcan1_sigmatek: flexcan1grp-sigmatek {
>              fsl,pins = <
>                  MX6QDL_PAD_SD3_CLK__FLEXCAN1_RX NO_PAD_CTRL
>                  MX6QDL_PAD_SD3_CMD__FLEXCAN1_TX NO_PAD_CTRL
>              >;
>          };
>      };
> 
>      flexcan2 {
>          pinctrl_flexcan2_sigmatek: flexcan2grp-sigmatek {
>              fsl,pins = <
>                  MX6QDL_PAD_SD3_DAT1__FLEXCAN2_RX NO_PAD_CTRL
>                  MX6QDL_PAD_SD3_DAT0__FLEXCAN2_TX NO_PAD_CTRL
>              >;
>          };
>      };
> };
> 
> /*
>   * CAN
>   */
> &flexcan1 {
>      pinctrl-names = "default";
>      pinctrl-0 = <&pinctrl_flexcan1_sigmatek>;
>      status = "okay";
> };
> 
> &flexcan2 {
>      pinctrl-names = "default";
>      pinctrl-0 = <&pinctrl_flexcan2_sigmatek>;
>      status = "okay";
> };

Hope that already helps.

Wolfgang.