[U-Boot] [PATCH v6 19/76] spi: Rename spi_read_then_write to spi_write_then_read

[Jagan Teki <jteki@openedev.com>]

Since spi_read_then_write moved into spi layer,
the meaning of data transfer is also change from
read_then_write to write_then_read, this means
first spi will write the opcode through and then
read the respective buffer.

Cc: Simon Glass <sjg@chromium.org>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Mugunthan V N <mugunthanvnm@ti.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Jagan Teki <jteki@openedev.com>
---
 drivers/mtd/spi-nor/m25p80.c |  8 ++++----
 drivers/spi/spi-uclass.c     | 19 +++++++++----------
 drivers/spi/spi.c            | 19 +++++++++----------
 include/spi.h                | 23 +++++++++++++++++++----
 4 files changed, 41 insertions(+), 28 deletions(-)

diff --git a/drivers/mtd/spi-nor/m25p80.c b/drivers/mtd/spi-nor/m25p80.c
index 4aefe93..7e2702d 100644
--- a/drivers/mtd/spi-nor/m25p80.c
+++ b/drivers/mtd/spi-nor/m25p80.c
@@ -39,7 +39,7 @@ static int m25p80_read_reg(struct spi_nor *nor, u8 cmd, u8 *val, int len)
 	if (nor->flags & SNOR_F_U_PAGE)
 		spi->flags |= SPI_XFER_U_PAGE;
 
-	ret = spi_read_then_write(spi, &cmd, 1, NULL, val, len);
+	ret = spi_write_then_read(spi, &cmd, 1, NULL, val, len);
 	if (ret < 0) {
 		debug("m25p80: error %d reading register %x\n", ret, cmd);
 		return ret;
@@ -65,7 +65,7 @@ static int m25p80_write_reg(struct spi_nor *nor, u8 cmd, u8 *buf, int len)
 	if (nor->flags & SNOR_F_U_PAGE)
 		spi->flags |= SPI_XFER_U_PAGE;
 
-	ret = spi_read_then_write(spi, &cmd, 1, buf, NULL, len);
+	ret = spi_write_then_read(spi, &cmd, 1, buf, NULL, len);
 	if (ret < 0) {
 		debug("m25p80: error %d writing register %x\n", ret, cmd);
 		return ret;
@@ -119,7 +119,7 @@ static int m25p80_read(struct spi_nor *nor, const u8 *cmd, size_t cmd_len,
 	if (nor->flags & SNOR_F_U_PAGE)
 		spi->flags |= SPI_XFER_U_PAGE;
 
-	ret = spi_read_then_write(spi, cmd, cmd_len, NULL, data, data_len);
+	ret = spi_write_then_read(spi, cmd, cmd_len, NULL, data, data_len);
 	if (ret < 0) {
 		debug("m25p80: error %d reading %x\n", ret, *cmd);
 		return ret;
@@ -146,7 +146,7 @@ static int m25p80_write(struct spi_nor *nor, const u8 *cmd, size_t cmd_len,
 	if (nor->flags & SNOR_F_U_PAGE)
 		spi->flags |= SPI_XFER_U_PAGE;
 
-	ret = spi_read_then_write(spi, cmd, cmd_len, data, NULL, data_len);
+	ret = spi_write_then_read(spi, cmd, cmd_len, data, NULL, data_len);
 	if (ret < 0) {
 		debug("m25p80: error %d writing %x\n", ret, *cmd);
 		return ret;
diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c
index 7728eac..0dfdd8b 100644
--- a/drivers/spi/spi-uclass.c
+++ b/drivers/spi/spi-uclass.c
@@ -95,26 +95,25 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
 	return spi_get_ops(bus)->xfer(dev, bitlen, dout, din, flags);
 }
 
-int spi_read_then_write(struct spi_slave *spi, const u8 *cmd,
-			size_t cmd_len, const u8 *data_out,
-			u8 *data_in, size_t data_len)
+int spi_write_then_read(struct spi_slave *slave, const u8 *opcode,
+			size_t n_opcode, const u8 *txbuf, u8 *rxbuf,
+			size_t n_buf)
 {
 	unsigned long flags = SPI_XFER_BEGIN;
 	int ret;
 
-	if (data_len == 0)
+	if (n_buf == 0)
 		flags |= SPI_XFER_END;
 
-	ret = spi_xfer(spi, cmd_len * 8, cmd, NULL, flags);
+	ret = spi_xfer(slave, n_opcode * 8, opcode, NULL, flags);
 	if (ret) {
 		debug("spi: failed to send command (%zu bytes): %d\n",
-		      cmd_len, ret);
-	} else if (data_len != 0) {
-		ret = spi_xfer(spi, data_len * 8, data_out, data_in,
-			       SPI_XFER_END);
+		      n_opcode, ret);
+	} else if (n_buf != 0) {
+		ret = spi_xfer(slave, n_buf * 8, txbuf, rxbuf, SPI_XFER_END);
 		if (ret)
 			debug("spi: failed to transfer %zu bytes of data: %d\n",
-			      data_len, ret);
+			      n_buf, ret);
 	}
 
 	return ret;
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index a050386..c8051f9 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -39,26 +39,25 @@ void *spi_do_alloc_slave(int offset, int size, unsigned int bus,
 	return ptr;
 }
 
-int spi_read_then_write(struct spi_slave *spi, const u8 *cmd,
-			size_t cmd_len, const u8 *data_out,
-			u8 *data_in, size_t data_len)
+int spi_write_then_read(struct spi_slave *slave, const u8 *opcode,
+			size_t n_opcode, const u8 *txbuf, u8 *rxbuf,
+			size_t n_buf)
 {
 	unsigned long flags = SPI_XFER_BEGIN;
 	int ret;
 
-	if (data_len == 0)
+	if (n_buf == 0)
 		flags |= SPI_XFER_END;
 
-	ret = spi_xfer(spi, cmd_len * 8, cmd, NULL, flags);
+	ret = spi_xfer(slave, n_opcode * 8, opcode, NULL, flags);
 	if (ret) {
 		debug("spi: failed to send command (%zu bytes): %d\n",
-		      cmd_len, ret);
-	} else if (data_len != 0) {
-		ret = spi_xfer(spi, data_len * 8, data_out, data_in,
-					SPI_XFER_END);
+		      n_opcode, ret);
+	} else if (n_buf != 0) {
+		ret = spi_xfer(slave, n_buf * 8, txbuf, rxbuf, SPI_XFER_END);
 		if (ret)
 			debug("spi: failed to transfer %zu bytes of data: %d\n",
-			      data_len, ret);
+			      n_buf, ret);
 	}
 
 	return ret;
diff --git a/include/spi.h b/include/spi.h
index 19589aa..dd0b11b 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -265,10 +265,25 @@ int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen);
 int  spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
 		void *din, unsigned long flags);
 
-/* spi_write_then_read - SPI synchronous read followed by write */
-int spi_read_then_write(struct spi_slave *spi, const u8 *cmd,
-                        size_t cmd_len, const u8 *data_out,
-                        u8 *data_in, size_t data_len);
+/**
+ * spi_write_then_read - SPI synchronous write followed by read
+ *
+ * This performs a half duplex transaction in which the first transaction
+ * is to send the opcode and if the length of buf is non-zero then it start
+ * the second transaction as tx or rx based on the need from respective slave.
+ *
+ * @slave:	slave device with which opcode/data will be exchanged
+ * @opcode:	opcode used for specific transfer
+ * @n_opcode:	size of opcode, in bytes
+ * @txbuf:	buffer into which data to be written
+ * @rxbuf:	buffer into which data will be read
+ * @n_buf:	size of buf (whether it's [tx|rx]buf), in bytes
+ *
+ * Returns: 0 on success, not 0 on failure
+ */
+int spi_write_then_read(struct spi_slave *slave, const u8 *opcode,
+			size_t n_opcode, const u8 *txbuf, u8 *rxbuf,
+			size_t n_buf);
 
 /* Copy memory mapped data */
 void spi_flash_copy_mmap(void *data, void *offset, size_t len);
-- 
1.9.1