Re: [Qemu-devel] [PATCH v2 1/2] xilinx_spips: Enable only two slaves when reading/writing with stripe

[Alistair Francis]

On Fri, Feb 23, 2018 at 3:22 PM, Francisco Iglesias
<address@hidden> wrote:
> Assert only the lower cs on bus 0 and upper cs on bus 1 when both buses and
> chip selects are enabled (e.g reading/writing with stripe).
>
> Signed-off-by: Francisco Iglesias <address@hidden>

Reviewed-by: Alistair Francis <address@hidden>
Tested-by: Alistair Francis <address@hidden>

Alistair

> ---
>  hw/ssi/xilinx_spips.c | 41 +++++++++++++++++++++++++++++++++++++----
>  1 file changed, 37 insertions(+), 4 deletions(-)
>
> diff --git a/hw/ssi/xilinx_spips.c b/hw/ssi/xilinx_spips.c
> index 8af36ca3d4..0cb484ecf4 100644
> --- a/hw/ssi/xilinx_spips.c
> +++ b/hw/ssi/xilinx_spips.c
> @@ -223,7 +223,7 @@ static void xilinx_spips_update_cs(XilinxSPIPS *s, int 
> field)
>  {
>      int i;
>
> -    for (i = 0; i < s->num_cs; i++) {
> +    for (i = 0; i < s->num_cs * s->num_busses; i++) {
>          bool old_state = s->cs_lines_state[i];
>          bool new_state = field & (1 << i);
>
> @@ -234,7 +234,7 @@ static void xilinx_spips_update_cs(XilinxSPIPS *s, int 
> field)
>          }
>          qemu_set_irq(s->cs_lines[i], !new_state);
>      }
> -    if (!(field & ((1 << s->num_cs) - 1))) {
> +    if (!(field & ((1 << (s->num_cs * s->num_busses)) - 1))) {
>          s->snoop_state = SNOOP_CHECKING;
>          s->cmd_dummies = 0;
>          s->link_state = 1;
> @@ -248,7 +248,40 @@ static void 
> xlnx_zynqmp_qspips_update_cs_lines(XlnxZynqMPQSPIPS *s)
>  {
>      if (s->regs[R_GQSPI_GF_SNAPSHOT]) {
>          int field = ARRAY_FIELD_EX32(s->regs, GQSPI_GF_SNAPSHOT, 
> CHIP_SELECT);
> -        xilinx_spips_update_cs(XILINX_SPIPS(s), field);
> +        bool upper_cs_sel = field & (1 << 1);
> +        bool lower_cs_sel = field & 1;
> +        bool bus0_enabled;
> +        bool bus1_enabled;
> +        uint8_t buses;
> +        int cs = 0;
> +
> +        buses = ARRAY_FIELD_EX32(s->regs, GQSPI_GF_SNAPSHOT, 
> DATA_BUS_SELECT);
> +        bus0_enabled = buses & 1;
> +        bus1_enabled = buses & (1 << 1);
> +
> +        if (bus0_enabled && bus1_enabled) {
> +            if (lower_cs_sel) {
> +                cs |= 1;
> +            }
> +            if (upper_cs_sel) {
> +                cs |= 1 << 3;
> +            }
> +        } else if (bus0_enabled) {
> +            if (lower_cs_sel) {
> +                cs |= 1;
> +            }
> +            if (upper_cs_sel) {
> +                cs |= 1 << 1;
> +            }
> +        } else if (bus1_enabled) {
> +            if (lower_cs_sel) {
> +                cs |= 1 << 2;
> +            }
> +            if (upper_cs_sel) {
> +                cs |= 1 << 3;
> +            }
> +        }
> +        xilinx_spips_update_cs(XILINX_SPIPS(s), cs);
>      }
>  }
>
> @@ -260,7 +293,7 @@ static void xilinx_spips_update_cs_lines(XilinxSPIPS *s)
>      if (num_effective_busses(s) == 2) {
>          /* Single bit chip-select for qspi */
>          field &= 0x1;
> -        field |= field << 1;
> +        field |= field << 3;
>      /* Dual stack U-Page */
>      } else if (s->regs[R_LQSPI_CFG] & LQSPI_CFG_TWO_MEM &&
>                 s->regs[R_LQSPI_STS] & LQSPI_CFG_U_PAGE) {
> --
> 2.11.0
>
>