hw/misc/mps2-scc: Make changes needed for AN536 FPGA image

The MPS2 SCC device is broadly the same for all FPGA images, but has
minor differences in the behaviour of the CFG registers depending on
the image. In many cases we don't really care about the functionality
controlled by these registers and a reads-as-written or similar
behaviour is sufficient for the moment.

For the AN536 the required behaviour is:

 * A_CFG0 has CPU reset and halt bits
    - implement as reads-as-written for the moment
 * A_CFG1 has flash or ATCM address 0 remap handling
    - QEMU doesn't model this; implement as reads-as-written
 * A_CFG2 has QSPI select (like AN524)
    - implemented (no behaviour, as with AN524)
 * A_CFG3 is MCC_MSB_ADDR "additional MCC addressing bits"
    - QEMU doesn't care about these, so use the existing
      RAZ behaviour for convenience
 * A_CFG4 is board rev (like all other images)
    - no change needed
 * A_CFG5 is ACLK frq in hz (like AN524)
    - implemented as reads-as-written, as for other boards
 * A_CFG6 is core 0 vector table base address
    - implemented as reads-as-written for the moment
 * A_CFG7 is core 1 vector table base address
    - implemented as reads-as-written for the moment

Make the changes necessary for this; leave TODO comments where
appropriate to indicate where we might want to come back and
implement things like CPU reset.

The other aspects of the device specific to this FPGA image (like the
values of the board ID and similar registers) will be set via the
device's qdev properties.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20240206132931.38376-8-peter.maydell@linaro.org

1 files changed, 1 insertions, 0 deletions

diff --git a/include/hw/misc/mps2-scc.h b/include/hw/misc/mps2-scc.h
index 3b2d13ac9c..8ff188c06b 100644
--- a/include/hw/misc/mps2-scc.h
+++ b/include/hw/misc/mps2-scc.h
@@ -51,6 +51,7 @@ struct MPS2SCC {
     uint32_t cfg4;
     uint32_t cfg5;
     uint32_t cfg6;
+    uint32_t cfg7;
     uint32_t cfgdata_rtn;
     uint32_t cfgdata_out;
     uint32_t cfgctrl;