From: Witold Sadowski wsadowski@marvell.com
[ Upstream commit 4a69c1264ff41bc5bf7c03101ada0454fbf08868 ]
During dummy-cycles xSPI will switch GPIO into Hi-Z mode. In that dummy period voltage on data lines will slowly drop, what can cause unintentional modebyte transmission. Value send to SPI memory chip will depend on last address, and clock frequency. To prevent unforeseen consequences of that behaviour, force send single modebyte(0x00). Modebyte will be send only if number of dummy-cycles is not equal to 0. Code must also reduce dummycycle byte count by one - as one byte is send as modebyte.
Signed-off-by: Witold Sadowski wsadowski@marvell.com Link: https://msgid.link/r/20240529074037.1345882-2-wsadowski@marvell.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-cadence-xspi.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/drivers/spi/spi-cadence-xspi.c b/drivers/spi/spi-cadence-xspi.c index 8648b8eb080dc..cdce2e280f663 100644 --- a/drivers/spi/spi-cadence-xspi.c +++ b/drivers/spi/spi-cadence-xspi.c @@ -145,6 +145,9 @@ #define CDNS_XSPI_STIG_DONE_FLAG BIT(0) #define CDNS_XSPI_TRD_STATUS 0x0104
+#define MODE_NO_OF_BYTES GENMASK(25, 24) +#define MODEBYTES_COUNT 1 + /* Helper macros for filling command registers */ #define CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_1(op, data_phase) ( \ FIELD_PREP(CDNS_XSPI_CMD_INSTR_TYPE, (data_phase) ? \ @@ -157,9 +160,10 @@ FIELD_PREP(CDNS_XSPI_CMD_P1_R2_ADDR3, ((op)->addr.val >> 24) & 0xFF) | \ FIELD_PREP(CDNS_XSPI_CMD_P1_R2_ADDR4, ((op)->addr.val >> 32) & 0xFF))
-#define CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_3(op) ( \ +#define CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_3(op, modebytes) ( \ FIELD_PREP(CDNS_XSPI_CMD_P1_R3_ADDR5, ((op)->addr.val >> 40) & 0xFF) | \ FIELD_PREP(CDNS_XSPI_CMD_P1_R3_CMD, (op)->cmd.opcode) | \ + FIELD_PREP(MODE_NO_OF_BYTES, modebytes) | \ FIELD_PREP(CDNS_XSPI_CMD_P1_R3_NUM_ADDR_BYTES, (op)->addr.nbytes))
#define CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_4(op, chipsel) ( \ @@ -173,12 +177,12 @@ #define CDNS_XSPI_CMD_FLD_DSEQ_CMD_2(op) \ FIELD_PREP(CDNS_XSPI_CMD_DSEQ_R2_DCNT_L, (op)->data.nbytes & 0xFFFF)
-#define CDNS_XSPI_CMD_FLD_DSEQ_CMD_3(op) ( \ +#define CDNS_XSPI_CMD_FLD_DSEQ_CMD_3(op, dummybytes) ( \ FIELD_PREP(CDNS_XSPI_CMD_DSEQ_R3_DCNT_H, \ ((op)->data.nbytes >> 16) & 0xffff) | \ FIELD_PREP(CDNS_XSPI_CMD_DSEQ_R3_NUM_OF_DUMMY, \ (op)->dummy.buswidth != 0 ? \ - (((op)->dummy.nbytes * 8) / (op)->dummy.buswidth) : \ + (((dummybytes) * 8) / (op)->dummy.buswidth) : \ 0))
#define CDNS_XSPI_CMD_FLD_DSEQ_CMD_4(op, chipsel) ( \ @@ -351,6 +355,7 @@ static int cdns_xspi_send_stig_command(struct cdns_xspi_dev *cdns_xspi, u32 cmd_regs[6]; u32 cmd_status; int ret; + int dummybytes = op->dummy.nbytes;
ret = cdns_xspi_wait_for_controller_idle(cdns_xspi); if (ret < 0) @@ -365,7 +370,12 @@ static int cdns_xspi_send_stig_command(struct cdns_xspi_dev *cdns_xspi, memset(cmd_regs, 0, sizeof(cmd_regs)); cmd_regs[1] = CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_1(op, data_phase); cmd_regs[2] = CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_2(op); - cmd_regs[3] = CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_3(op); + if (dummybytes != 0) { + cmd_regs[3] = CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_3(op, 1); + dummybytes--; + } else { + cmd_regs[3] = CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_3(op, 0); + } cmd_regs[4] = CDNS_XSPI_CMD_FLD_P1_INSTR_CMD_4(op, cdns_xspi->cur_cs);
@@ -375,7 +385,7 @@ static int cdns_xspi_send_stig_command(struct cdns_xspi_dev *cdns_xspi, cmd_regs[0] = CDNS_XSPI_STIG_DONE_FLAG; cmd_regs[1] = CDNS_XSPI_CMD_FLD_DSEQ_CMD_1(op); cmd_regs[2] = CDNS_XSPI_CMD_FLD_DSEQ_CMD_2(op); - cmd_regs[3] = CDNS_XSPI_CMD_FLD_DSEQ_CMD_3(op); + cmd_regs[3] = CDNS_XSPI_CMD_FLD_DSEQ_CMD_3(op, dummybytes); cmd_regs[4] = CDNS_XSPI_CMD_FLD_DSEQ_CMD_4(op, cdns_xspi->cur_cs);