TDA4VM: GPMC access from the DSP

Hello,

With Steve, we were able to use the GPMC interface from the C66xx DSP (DSP1) with a firmware loaded by Linux (remoteproc) using an AM57xx SoC.

We used the GPMC API from the csl library and we had to create two new TYPE_DEVMEM entries in the custom ipc resource table to allow GPMC access (otherwise the firmware crash with a mmufault).

#define DSP_PERIPHERAL_FPGA     0x14000000
#define PHYS_PERIPHERAL_FPGA    0x14000000

#define DSP_GPMC_L3             0x50000000
#define PHYS_GPMC_L3            0x50000000


    {
        TYPE_DEVMEM,
        DSP_GPMC_L3, PHYS_GPMC_L3,
        DSP_GPMC_L3_SIZE, 0, 0, "DSP_GPMC_L3",
    },

    {
        TYPE_DEVMEM,
        DSP_PERIPHERAL_FPGA, PHYS_PERIPHERAL_FPGA,
        FPGA_MEM_SIZE, 0, 0, "FPGA_MEM",
    },

Now we have to do something similar on the TDA4VM SoC.

But the TDA4VM PDK doesn't provide anymore the IPC resource table with fw_rsc_devmem entry.
As soon as try to add one of them in Ipc_ResourceTable, the resource table is rejected by the remoteproc driver.

TYPE_DEVMEM and TYPE_CARVEOUT doesn't seem used anywhere in the PDK, are they still needed?

If the default resource table (ti/drv/ipc/examples/common/src/ipc_rsctable.h) is enough for our use case, I don't understand why why the GPMC is not working.
The GPMC activity is checked by adding an oscilloscope probe on the GPMC0_CS0 signal and trying to read periodically the GPMC datas from the DSP firmware.
We checked that the GPMC0_CS0 pinmux is correct (AF21 mode 8).

Do we need to do something else ?

Best regards,
Romain