[PATCH v2] spi: intel: Implement dirmap hooks

[Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>]

Currently the driver goes over the supported opcodes list each time
->exec_op() is called and finds the suitable for the given operation.
This consumes unnecessary amount of CPU cycles because the operation is
always the same. For this reason populate dirmap hooks for the driver so
that we cache the selected operation and then simply call it on each
read/write.

Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
v1: https://lore.kernel.org/linux-spi/20220411113158.2037-2-mika.westerberg@xxxxxxxxxxxxxxx/

Changes from v1:

  * Fix build error by passing correct number of arguments to ->exec_op().

 drivers/spi/spi-intel.c | 49 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/drivers/spi/spi-intel.c b/drivers/spi/spi-intel.c
index 1bdb227e0ca2..50f42983b950 100644
--- a/drivers/spi/spi-intel.c
+++ b/drivers/spi/spi-intel.c
@@ -779,10 +779,59 @@ static const char *intel_spi_get_name(struct spi_mem *mem)
 	return dev_name(ispi->dev);
 }
 
+static int intel_spi_dirmap_create(struct spi_mem_dirmap_desc *desc)
+{
+	struct intel_spi *ispi = spi_master_get_devdata(desc->mem->spi->master);
+	const struct intel_spi_mem_op *iop;
+
+	iop = intel_spi_match_mem_op(ispi, &desc->info.op_tmpl);
+	if (!iop)
+		return -EOPNOTSUPP;
+
+	desc->priv = (void *)iop;
+	return 0;
+}
+
+static ssize_t intel_spi_dirmap_read(struct spi_mem_dirmap_desc *desc, u64 offs,
+				     size_t len, void *buf)
+{
+	struct intel_spi *ispi = spi_master_get_devdata(desc->mem->spi->master);
+	const struct intel_spi_mem_op *iop = desc->priv;
+	struct spi_mem_op op = desc->info.op_tmpl;
+	int ret;
+
+	/* Fill in the gaps */
+	op.addr.val = offs;
+	op.data.nbytes = len;
+	op.data.buf.in = buf;
+
+	ret = iop->exec_op(ispi, iop, &op);
+	return ret ? ret : len;
+}
+
+static ssize_t intel_spi_dirmap_write(struct spi_mem_dirmap_desc *desc, u64 offs,
+				      size_t len, const void *buf)
+{
+	struct intel_spi *ispi = spi_master_get_devdata(desc->mem->spi->master);
+	const struct intel_spi_mem_op *iop = desc->priv;
+	struct spi_mem_op op = desc->info.op_tmpl;
+	int ret;
+
+	op.addr.val = offs;
+	op.data.nbytes = len;
+	op.data.buf.out = buf;
+
+	ret = iop->exec_op(ispi, iop, &op);
+	return ret ? ret : len;
+}
+
 static const struct spi_controller_mem_ops intel_spi_mem_ops = {
 	.supports_op = intel_spi_supports_mem_op,
 	.exec_op = intel_spi_exec_mem_op,
 	.get_name = intel_spi_get_name,
+	.dirmap_create = intel_spi_dirmap_create,
+	.dirmap_read = intel_spi_dirmap_read,
+	.dirmap_write = intel_spi_dirmap_write,
 };
 
 #define INTEL_SPI_OP_ADDR(__nbytes)					\
-- 
2.35.1