spi: spi-mem: allow specifying whether an op is DTR or not

Each phase is given a separate 'dtr' field so mixed protocols like
4S-4D-4D can be supported.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/include/spi-mem.h b/include/spi-mem.h
index e354c38..8bd4459 100644
--- a/include/spi-mem.h
+++ b/include/spi-mem.h
@@ -71,6 +71,7 @@
  * struct spi_mem_op - describes a SPI memory operation
  * @cmd.buswidth: number of IO lines used to transmit the command
  * @cmd.opcode: operation opcode
+ * @cmd.dtr: whether the command opcode should be sent in DTR mode or not
  * @addr.nbytes: number of address bytes to send. Can be zero if the operation
  *		 does not need to send an address
  * @addr.buswidth: number of IO lines used to transmit the address cycles
@@ -78,10 +79,13 @@
  *	      Note that only @addr.nbytes are taken into account in this
  *	      address value, so users should make sure the value fits in the
  *	      assigned number of bytes.
+ * @addr.dtr: whether the address should be sent in DTR mode or not
  * @dummy.nbytes: number of dummy bytes to send after an opcode or address. Can
  *		  be zero if the operation does not require dummy bytes
  * @dummy.buswidth: number of IO lanes used to transmit the dummy bytes
+ * @dummy.dtr: whether the dummy bytes should be sent in DTR mode or not
  * @data.buswidth: number of IO lanes used to send/receive the data
+ * @data.dtr: whether the data should be sent in DTR mode or not
  * @data.dir: direction of the transfer
  * @data.buf.in: input buffer
  * @data.buf.out: output buffer
@@ -90,21 +94,25 @@
 	struct {
 		u8 buswidth;
 		u8 opcode;
+		u8 dtr : 1;
 	} cmd;
 
 	struct {
 		u8 nbytes;
 		u8 buswidth;
+		u8 dtr : 1;
 		u64 val;
 	} addr;
 
 	struct {
 		u8 nbytes;
 		u8 buswidth;
+		u8 dtr : 1;
 	} dummy;
 
 	struct {
 		u8 buswidth;
+		u8 dtr : 1;
 		enum spi_mem_data_dir dir;
 		unsigned int nbytes;
 		/* buf.{in,out} must be DMA-able. */