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[18/30] spi: cadence_qspi: Set tshsl_ns to at least one sclk_ns

Message ID 20231206053353.3745918-9-tejas.arvind.bhumkar@amd.com
State Superseded
Delegated to: Jagannadha Sutradharudu Teki
Headers show
Series Fix issues with QSPI and OSPI compare failures | expand

Commit Message

Bhumkar, Tejas Arvind Dec. 6, 2023, 5:33 a.m. UTC 
From: Ashok Reddy Soma <ashok.reddy.soma@amd.com>

tshsl_ns is the clock delay for chip select deassert. This is the delay in
master reference clocks for the length that the master mode chip select
outputs are de-asserted between transactions.

The minimum delay is always SCLK period to ensure the chip select is never
re-asserted within one SCLK period.

That is why tshsl_ns delay should be at least one sclk_ns value. If it is
less than sclk_ns, set it equal to sclk_ns.

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@amd.com>
Signed-off-by: Tejas Bhumkar <tejas.arvind.bhumkar@amd.com>
---
 drivers/spi/cadence_qspi_apb.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c
index 1b649abf21..0bb46f6ac2 100644
--- a/drivers/spi/cadence_qspi_apb.c
+++ b/drivers/spi/cadence_qspi_apb.c
@@ -306,6 +306,10 @@  void cadence_qspi_apb_delay(void *reg_base,
 		tshsl_ns -= sclk_ns + ref_clk_ns;
 	if (tchsh_ns >= sclk_ns + 3 * ref_clk_ns)
 		tchsh_ns -= sclk_ns + 3 * ref_clk_ns;
+
+	if (tshsl_ns < sclk_ns)
+		tshsl_ns = sclk_ns;
+
 	tshsl = DIV_ROUND_UP(tshsl_ns, ref_clk_ns);
 	tchsh = DIV_ROUND_UP(tchsh_ns, ref_clk_ns);
 	tslch = DIV_ROUND_UP(tslch_ns, ref_clk_ns);