[PATCH v2 5/7] mtd: devices: m25p80: Use the spi-mem dirmap API

[Boris Brezillon <boris.brezillon@xxxxxxxxxxx>]

Make use of the spi-mem direct mapping API to let advanced controllers
optimize read/write operations when they support direct mapping.

Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
---
Changes in v2:
- Rename the dirmap fields
- Return directly after calling dirmap_read/write() and let the spi-nor
  framework call us again if those functions returned less than the
  requested length
---
 drivers/mtd/devices/m25p80.c | 142 ++++++++++++++++++++++-------------
 1 file changed, 89 insertions(+), 53 deletions(-)

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index c4a1d04b8c80..55cf3b2e1dc1 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -31,6 +31,10 @@
 struct m25p {
 	struct spi_mem		*spimem;
 	struct spi_nor		spi_nor;
+	struct {
+		struct spi_mem_dirmap_desc *rdesc;
+		struct spi_mem_dirmap_desc *wdesc;
+	} dirmap;
 };
 
 static int m25p80_read_reg(struct spi_nor *nor, u8 code, u8 *val, int len)
@@ -85,31 +89,8 @@ static ssize_t m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
 			    const u_char *buf)
 {
 	struct m25p *flash = nor->priv;
-	struct spi_mem_op op =
-			SPI_MEM_OP(SPI_MEM_OP_CMD(nor->program_opcode, 1),
-				   SPI_MEM_OP_ADDR(nor->addr_width, to, 1),
-				   SPI_MEM_OP_NO_DUMMY,
-				   SPI_MEM_OP_DATA_OUT(len, buf, 1));
-	int ret;
-
-	/* get transfer protocols. */
-	op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->write_proto);
-	op.addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->write_proto);
-	op.data.buswidth = spi_nor_get_protocol_data_nbits(nor->write_proto);
-
-	if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
-		op.addr.nbytes = 0;
-
-	ret = spi_mem_adjust_op_size(flash->spimem, &op);
-	if (ret)
-		return ret;
-	op.data.nbytes = len < op.data.nbytes ? len : op.data.nbytes;
-
-	ret = spi_mem_exec_op(flash->spimem, &op);
-	if (ret)
-		return ret;
 
-	return op.data.nbytes;
+	return spi_mem_dirmap_write(flash->dirmap.wdesc, to, len, buf);
 }
 
 /*
@@ -120,39 +101,66 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
 			   u_char *buf)
 {
 	struct m25p *flash = nor->priv;
-	struct spi_mem_op op =
-			SPI_MEM_OP(SPI_MEM_OP_CMD(nor->read_opcode, 1),
-				   SPI_MEM_OP_ADDR(nor->addr_width, from, 1),
-				   SPI_MEM_OP_DUMMY(nor->read_dummy, 1),
-				   SPI_MEM_OP_DATA_IN(len, buf, 1));
-	size_t remaining = len;
-	int ret;
+
+	return spi_mem_dirmap_read(flash->dirmap.rdesc, from, len, buf);
+}
+
+static int m25p_create_write_dirmap(struct m25p *flash)
+{
+	struct spi_nor *nor = &flash->spi_nor;
+	struct spi_mem_dirmap_info info = {
+		.op_tmpl = SPI_MEM_OP(SPI_MEM_OP_CMD(nor->program_opcode, 1),
+				      SPI_MEM_OP_ADDR(nor->addr_width, 0, 1),
+				      SPI_MEM_OP_NO_DUMMY,
+				      SPI_MEM_OP_DATA_OUT(0, NULL, 1)),
+		.offset = 0,
+		.length = flash->spi_nor.mtd.size,
+	};
+	struct spi_mem_op *op = &info.op_tmpl;
 
 	/* get transfer protocols. */
-	op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->read_proto);
-	op.addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->read_proto);
-	op.dummy.buswidth = op.addr.buswidth;
-	op.data.buswidth = spi_nor_get_protocol_data_nbits(nor->read_proto);
+	op->cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->write_proto);
+	op->addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->write_proto);
+	op->dummy.buswidth = op->addr.buswidth;
+	op->data.buswidth = spi_nor_get_protocol_data_nbits(nor->write_proto);
 
-	/* convert the dummy cycles to the number of bytes */
-	op.dummy.nbytes = (nor->read_dummy * op.dummy.buswidth) / 8;
+	if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
+		op->addr.nbytes = 0;
 
-	while (remaining) {
-		op.data.nbytes = remaining < UINT_MAX ? remaining : UINT_MAX;
-		ret = spi_mem_adjust_op_size(flash->spimem, &op);
-		if (ret)
-			return ret;
+	flash->dirmap.wdesc = spi_mem_dirmap_create(flash->spimem, &info);
+	if (IS_ERR(flash->dirmap.wdesc))
+		return PTR_ERR(flash->dirmap.wdesc);
 
-		ret = spi_mem_exec_op(flash->spimem, &op);
-		if (ret)
-			return ret;
+	return 0;
+}
 
-		op.addr.val += op.data.nbytes;
-		remaining -= op.data.nbytes;
-		op.data.buf.in += op.data.nbytes;
-	}
+static int m25p_create_read_dirmap(struct m25p *flash)
+{
+	struct spi_nor *nor = &flash->spi_nor;
+	struct spi_mem_dirmap_info info = {
+		.op_tmpl = SPI_MEM_OP(SPI_MEM_OP_CMD(nor->read_opcode, 1),
+				      SPI_MEM_OP_ADDR(nor->addr_width, 0, 1),
+				      SPI_MEM_OP_DUMMY(nor->read_dummy, 1),
+				      SPI_MEM_OP_DATA_IN(0, NULL, 1)),
+		.offset = 0,
+		.length = flash->spi_nor.mtd.size,
+	};
+	struct spi_mem_op *op = &info.op_tmpl;
+
+	/* get transfer protocols. */
+	op->cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->read_proto);
+	op->addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->read_proto);
+	op->dummy.buswidth = op->addr.buswidth;
+	op->data.buswidth = spi_nor_get_protocol_data_nbits(nor->read_proto);
+
+	/* convert the dummy cycles to the number of bytes */
+	op->dummy.nbytes = (nor->read_dummy * op->dummy.buswidth) / 8;
+
+	flash->dirmap.rdesc = spi_mem_dirmap_create(flash->spimem, &info);
+	if (IS_ERR(flash->dirmap.rdesc))
+		return PTR_ERR(flash->dirmap.rdesc);
 
-	return len;
+	return 0;
 }
 
 /*
@@ -231,19 +239,47 @@ static int m25p_probe(struct spi_mem *spimem)
 	if (ret)
 		return ret;
 
-	return mtd_device_register(&nor->mtd, data ? data->parts : NULL,
-				   data ? data->nr_parts : 0);
+	ret = m25p_create_write_dirmap(flash);
+	if (ret)
+		return ret;
+
+	ret = m25p_create_read_dirmap(flash);
+	if (ret)
+		goto err_destroy_write_dirmap;
+
+	ret = mtd_device_register(&nor->mtd, data ? data->parts : NULL,
+				  data ? data->nr_parts : 0);
+	if (ret)
+		goto err_destroy_read_dirmap;
+
+	return 0;
+
+err_destroy_read_dirmap:
+	spi_mem_dirmap_destroy(flash->dirmap.rdesc);
+
+err_destroy_write_dirmap:
+	spi_mem_dirmap_destroy(flash->dirmap.wdesc);
+
+	return ret;
 }
 
 
 static int m25p_remove(struct spi_mem *spimem)
 {
 	struct m25p	*flash = spi_mem_get_drvdata(spimem);
+	int ret;
 
 	spi_nor_restore(&flash->spi_nor);
 
 	/* Clean up MTD stuff. */
-	return mtd_device_unregister(&flash->spi_nor.mtd);
+	ret = mtd_device_unregister(&flash->spi_nor.mtd);
+	if (ret)
+		return ret;
+
+	spi_mem_dirmap_destroy(flash->dirmap.rdesc);
+	spi_mem_dirmap_destroy(flash->dirmap.wdesc);
+
+	return 0;
 }
 
 static void m25p_shutdown(struct spi_mem *spimem)
-- 
2.17.1