spi: Define and use spi_ctrlr structure

1. Define a new structure spi_ctrlr that allows platforms to define
callbacks for spi operations (claim bus, release bus, transfer).
2. Add a new member (pointer to spi_ctrlr structure) in spi_slave
structure which will be initialized by call to spi_setup_slave.
3. Define spi_claim_bus, spi_release_bus and spi_xfer in spi-generic.c
which will make appropriate calls to ctrlr functions.

BUG=chrome-os-partner:59832
BRANCH=None
TEST=Compiles successfully

Change-Id: Icb2326e3aab1e8f4bef53f553f82b3836358c55e
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/17684
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 13 insertions, 19 deletions

diff --git a/src/southbridge/amd/sb700/spi.c b/src/southbridge/amd/sb700/spi.c
index fca401cbbf..2e16ca8d5c 100644
--- a/src/southbridge/amd/sb700/spi.c
+++ b/src/southbridge/amd/sb700/spi.c
@@ -65,25 +65,7 @@ static void execute_command(void)
 		(read8((void *)(spibar+3)) & 0x80));
 }
 
-int spi_claim_bus(const struct spi_slave *slave)
-{
-	/* Handled internally by the SB700 */
-	return 0;
-}
-
-void spi_release_bus(const struct spi_slave *slave)
-{
-	/* Handled internally by the SB700 */
-}
-
-int spi_setup_slave(unsigned int bus, unsigned int cs, struct spi_slave *slave)
-{
-	slave->bus = bus;
-	slave->cs = cs;
-	return 0;
-}
-
-int spi_xfer(const struct spi_slave *slave, const void *dout,
+static int spi_ctrlr_xfer(const struct spi_slave *slave, const void *dout,
 		size_t bytesout, void *din, size_t bytesin)
 {
 	/* First byte is cmd which cannot be sent through the FIFO. */
@@ -135,3 +117,15 @@ int spi_xfer(const struct spi_slave *slave, const void *dout,
 
 	return 0;
 }
+
+static const struct spi_ctrlr spi_ctrlr = {
+	.xfer = spi_ctrlr_xfer,
+};
+
+int spi_setup_slave(unsigned int bus, unsigned int cs, struct spi_slave *slave)
+{
+	slave->bus = bus;
+	slave->cs = cs;
+	slave->ctrlr = &spi_ctrlr;
+	return 0;
+}