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Re: [Qemu-devel] [PATCH 1/2] xilinx_spips: Enable only two slaves when r
From: |
Alistair Francis |
Subject: |
Re: [Qemu-devel] [PATCH 1/2] xilinx_spips: Enable only two slaves when reading/writing with stripe |
Date: |
Thu, 22 Feb 2018 14:38:23 -0800 |
On Thu, Feb 22, 2018 at 2:28 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>
> ---
> hw/ssi/xilinx_spips.c | 42 ++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 38 insertions(+), 4 deletions(-)
>
> diff --git a/hw/ssi/xilinx_spips.c b/hw/ssi/xilinx_spips.c
> index 8af36ca3d4..e566d179fe 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 +248,41 @@ 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 both_buses_enabled;
> + uint8_t buses;
> + int cs = 0;
> +
> + buses = ARRAY_FIELD_EX32(s->regs, GQSPI_GF_SNAPSHOT,
> DATA_BUS_SELECT);
> + both_buses_enabled = (buses & 0x3) == 0x3;
> +
> + if (both_buses_enabled) {
> + /* Bus 0 lower cs */
> + if (field & 1) {
> + cs |= 1;
> + }
> + /* Bus 1 upper cs */
> + if (field & (1 << 1)) {
> + cs |= 1 << 3;
> + }
> + } else {
> + /* Bus 0 lower cs */
> + if (buses & 1 && field & 1) {
> + cs |= 1;
> + }
> + /* Bus 0 upper cs */
> + if (buses & 1 && field & (1 << 1)) {
> + cs |= 1 << 1;
> + }
> + /* Bus 1 lower cs */
> + if (buses & (1 << 1) && field & 1) {
> + cs |= 1 << 2;
> + }
> + /* Bus 1 upper cs */
> + if (buses & (1 << 1) && field & (1 << 1)) {
> + cs |= 1 << 3;
> + }
It might make more sense to have the buses & 1 in it's own if
statement and have nested if statements here. Just to be easier to
follow.
Tested-by: Alistair Francis <address@hidden>
Alistair
> + }
> + xilinx_spips_update_cs(XILINX_SPIPS(s), cs);
> }
> }
>
> @@ -260,7 +294,7 @@ 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
>
>