[PATCH v6 02/21] spi: spi-mem: allow specifying a command's extension

[Pratyush Yadav]

In xSPI mode, flashes expect 2-byte opcodes. The second byte is called
the "command extension". There can be 3 types of extensions in xSPI:
repeat, invert, and hex. When the extension type is "repeat", the same
opcode is sent twice. When it is "invert", the second byte is the
inverse of the opcode. When it is "hex" an additional opcode byte based
is sent with the command whose value can be anything.

So, make opcode a 16-bit value and add a 'nbytes', similar to how
multiple address widths are handled.

All usages of sizeof(op->cmd.opcode) also need to be changed to be
op->cmd.nbytes because that is the actual indicator of opcode size.

Signed-off-by: Pratyush Yadav <p.yadav at ti.com>
---
 drivers/spi/mtk_snfi_spi.c |  3 +--
 drivers/spi/spi-mem-nodm.c |  4 ++--
 drivers/spi/spi-mem.c      | 13 +++++++------
 include/spi-mem.h          |  6 +++++-
 4 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/spi/mtk_snfi_spi.c b/drivers/spi/mtk_snfi_spi.c
index 2a89476515..79e9fac265 100644
--- a/drivers/spi/mtk_snfi_spi.c
+++ b/drivers/spi/mtk_snfi_spi.c
@@ -64,8 +64,7 @@ static int mtk_snfi_adjust_op_size(struct spi_slave *slave,
 	 * or the output+input data must not exceed the GPRAM size.
 	 */
 
-	nbytes = sizeof(op->cmd.opcode) + op->addr.nbytes +
-		op->dummy.nbytes;
+	nbytes = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
 
 	if (nbytes + op->data.nbytes <= SNFI_GPRAM_SIZE)
 		return 0;
diff --git a/drivers/spi/spi-mem-nodm.c b/drivers/spi/spi-mem-nodm.c
index 765f05fe54..db54101383 100644
--- a/drivers/spi/spi-mem-nodm.c
+++ b/drivers/spi/spi-mem-nodm.c
@@ -27,7 +27,7 @@ int spi_mem_exec_op(struct spi_slave *slave,
 			tx_buf = op->data.buf.out;
 	}
 
-	op_len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;
+	op_len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
 	op_buf = calloc(1, op_len);
 
 	ret = spi_claim_bus(slave);
@@ -89,7 +89,7 @@ int spi_mem_adjust_op_size(struct spi_slave *slave,
 {
 	unsigned int len;
 
-	len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;
+	len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
 	if (slave->max_write_size && len > slave->max_write_size)
 		return -EINVAL;
 
diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index 967c241853..34d947db5d 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -162,6 +162,9 @@ bool spi_mem_default_supports_op(struct spi_slave *slave,
 	if (op->cmd.dtr || op->addr.dtr || op->dummy.dtr || op->data.dtr)
 		return false;
 
+	if (op->cmd.nbytes != 1)
+		return false;
+
 	return true;
 }
 EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);
@@ -268,8 +271,7 @@ int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op)
 	}
 
 #ifndef __UBOOT__
-	tmpbufsize = sizeof(op->cmd.opcode) + op->addr.nbytes +
-		     op->dummy.nbytes;
+	tmpbufsize = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
 
 	/*
 	 * Allocate a buffer to transmit the CMD, ADDR cycles with kmalloc() so
@@ -284,7 +286,7 @@ int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op)
 
 	tmpbuf[0] = op->cmd.opcode;
 	xfers[xferpos].tx_buf = tmpbuf;
-	xfers[xferpos].len = sizeof(op->cmd.opcode);
+	xfers[xferpos].len = op->cmd.nbytes;
 	xfers[xferpos].tx_nbits = op->cmd.buswidth;
 	spi_message_add_tail(&xfers[xferpos], &msg);
 	xferpos++;
@@ -348,7 +350,7 @@ int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op)
 			tx_buf = op->data.buf.out;
 	}
 
-	op_len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;
+	op_len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
 
 	/*
 	 * Avoid using malloc() here so that we can use this code in SPL where
@@ -437,8 +439,7 @@ int spi_mem_adjust_op_size(struct spi_slave *slave, struct spi_mem_op *op)
 	if (!ops->mem_ops || !ops->mem_ops->exec_op) {
 		unsigned int len;
 
-		len = sizeof(op->cmd.opcode) + op->addr.nbytes +
-			op->dummy.nbytes;
+		len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
 		if (slave->max_write_size && len > slave->max_write_size)
 			return -EINVAL;
 
diff --git a/include/spi-mem.h b/include/spi-mem.h
index 55e5019a1c..9167c435f6 100644
--- a/include/spi-mem.h
+++ b/include/spi-mem.h
@@ -20,6 +20,7 @@
 	{							\
 		.buswidth = __buswidth,				\
 		.opcode = __opcode,				\
+		.nbytes = 1,					\
 	}
 
 #define SPI_MEM_OP_ADDR(__nbytes, __val, __buswidth)		\
@@ -72,6 +73,8 @@ enum spi_mem_data_dir {
 
 /**
  * struct spi_mem_op - describes a SPI memory operation
+ * @cmd.nbytes: number of opcode bytes (only 1 or 2 are valid). The opcode is
+ *		sent MSB-first.
  * @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
@@ -95,9 +98,10 @@ enum spi_mem_data_dir {
  */
 struct spi_mem_op {
 	struct {
+		u8 nbytes;
 		u8 buswidth;
-		u8 opcode;
 		u8 dtr : 1;
+		u16 opcode;
 	} cmd;
 
 	struct {
-- 
2.27.0