spi: cadence-qspi: Add support for octal DTR flashes

Set up opcode extension and enable/disable DTR mode based on whether the
command is DTR or not.

xSPI flashes can have a 4-byte dummy address associated with some
commands like the Read Status Register command in octal DTR mode. Since
the flash does not support sending the dummy address, we can not use
automatic write completion polling in DTR mode. Further, no write
completion polling makes it impossible to use DAC mode for DTR writes.
In that mode, the controller does not know beforehand how long a write
will be and so it can de-assert Chip Select (CS#) at any time. Once CS#
is de-assert, the flash will go into burning phase. But since the
controller does not do write completion polling, it does not know when
the flash is busy and might send in writes while the flash is not ready.

So, disable write completion polling and make writes go through indirect
mode for DTR writes and let spi-mem take care of polling the SR.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>

1 files changed, 33 insertions, 6 deletions

diff --git a/drivers/spi/cadence_qspi.c b/drivers/spi/cadence_qspi.c
index a961193cdc..d1b3808c4d 100644
--- a/drivers/spi/cadence_qspi.c
+++ b/drivers/spi/cadence_qspi.c
@@ -43,20 +43,22 @@ static int cadence_spi_write_speed(struct udevice *bus, uint hz)
 	return 0;
 }
 
-static int cadence_spi_read_id(void *reg_base, u8 len, u8 *idcode)
+static int cadence_spi_read_id(struct cadence_spi_plat *plat, u8 len,
+			       u8 *idcode)
 {
 	struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(0x9F, 1),
 					  SPI_MEM_OP_NO_ADDR,
 					  SPI_MEM_OP_NO_DUMMY,
 					  SPI_MEM_OP_DATA_IN(len, idcode, 1));
 
-	return cadence_qspi_apb_command_read(reg_base, &op);
+	return cadence_qspi_apb_command_read(plat, &op);
 }
 
 /* Calibration sequence to determine the read data capture delay register */
 static int spi_calibration(struct udevice *bus, uint hz)
 {
 	struct cadence_spi_priv *priv = dev_get_priv(bus);
+	struct cadence_spi_plat *plat = dev_get_plat(bus);
 	void *base = priv->regbase;
 	unsigned int idcode = 0, temp = 0;
 	int err = 0, i, range_lo = -1, range_hi = -1;
@@ -71,7 +73,7 @@ static int spi_calibration(struct udevice *bus, uint hz)
 	cadence_qspi_apb_controller_enable(base);
 
 	/* read the ID which will be our golden value */
-	err = cadence_spi_read_id(base, 3, (u8 *)&idcode);
+	err = cadence_spi_read_id(plat, 3, (u8 *)&idcode);
 	if (err) {
 		puts("SF: Calibration failed (read)\n");
 		return err;
@@ -90,7 +92,7 @@ static int spi_calibration(struct udevice *bus, uint hz)
 		cadence_qspi_apb_controller_enable(base);
 
 		/* issue a RDID to get the ID value */
-		err = cadence_spi_read_id(base, 3, (u8 *)&temp);
+		err = cadence_spi_read_id(plat, 3, (u8 *)&temp);
 		if (err) {
 			puts("SF: Calibration failed (read)\n");
 			return err;
@@ -271,10 +273,14 @@ static int cadence_spi_mem_exec_op(struct spi_slave *spi,
 
 	switch (mode) {
 	case CQSPI_STIG_READ:
-		err = cadence_qspi_apb_command_read(base, op);
+		err = cadence_qspi_apb_command_read_setup(plat, op);
+		if (!err)
+			err = cadence_qspi_apb_command_read(plat, op);
 		break;
 	case CQSPI_STIG_WRITE:
-		err = cadence_qspi_apb_command_write(base, op);
+		err = cadence_qspi_apb_command_write_setup(plat, op);
+		if (!err)
+			err = cadence_qspi_apb_command_write(plat, op);
 		break;
 	case CQSPI_READ:
 		err = cadence_qspi_apb_read_setup(plat, op);
@@ -294,6 +300,26 @@ static int cadence_spi_mem_exec_op(struct spi_slave *spi,
 	return err;
 }
 
+static bool cadence_spi_mem_supports_op(struct spi_slave *slave,
+					const struct spi_mem_op *op)
+{
+	bool all_true, all_false;
+
+	all_true = op->cmd.dtr && op->addr.dtr && op->dummy.dtr &&
+		   op->data.dtr;
+	all_false = !op->cmd.dtr && !op->addr.dtr && !op->dummy.dtr &&
+		    !op->data.dtr;
+
+	/* Mixed DTR modes not supported. */
+	if (!(all_true || all_false))
+		return false;
+
+	if (all_true)
+		return spi_mem_dtr_supports_op(slave, op);
+	else
+		return spi_mem_default_supports_op(slave, op);
+}
+
 static int cadence_spi_of_to_plat(struct udevice *bus)
 {
 	struct cadence_spi_plat *plat = dev_get_plat(bus);
@@ -350,6 +376,7 @@ static int cadence_spi_of_to_plat(struct udevice *bus)
 
 static const struct spi_controller_mem_ops cadence_spi_mem_ops = {
 	.exec_op = cadence_spi_mem_exec_op,
+	.supports_op = cadence_spi_mem_supports_op,
 };
 
 static const struct dm_spi_ops cadence_spi_ops = {