[U-Boot] [PATCH 2/3] spi/kirkwood: support spi_claim/release_bus functions

[Valentin Longchamp]

These two function nows ensure that the MPP is configured correctly for
the SPI controller before any SPI access, and restore the initial
configuration when the access is over.

Since the used pins for the SPI controller can differ (2 possibilities
for each signal), the used pins are configured with CONFIG_SYS_KW_SPI_MPP.

Signed-off-by: Valentin Longchamp <valentin.longchamp at keymile.com>
cc: Holger Brunck <holger.brunck at keymile.com>
cc: Prafulla Wadaskar <prafulla at marvell.com>
---
 arch/arm/include/asm/arch-kirkwood/spi.h |    9 ++++++++
 drivers/spi/kirkwood_spi.c               |   34 ++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 0 deletions(-)

diff --git a/arch/arm/include/asm/arch-kirkwood/spi.h b/arch/arm/include/asm/arch-kirkwood/spi.h
index 1d5043f..305c573 100644
--- a/arch/arm/include/asm/arch-kirkwood/spi.h
+++ b/arch/arm/include/asm/arch-kirkwood/spi.h
@@ -37,6 +37,15 @@ struct kwspi_registers {
 	u32 irq_mask;	/* 0x10614 */
 };
 
+#define CSn_MPP7	0x1
+#define MOSI_MPP6	0x2
+#define SCK_MPP10	0x4
+#define MISO_MPP11	0x8
+
+#ifndef CONFIG_SYS_KW_SPI_MPP
+#define CONFIG_SYS_KW_SPI_MPP	0x0
+#endif
+
 #define KWSPI_CLKPRESCL_MASK	0x1f
 #define KWSPI_CSN_ACT		1 /* Activates serial memory interface */
 #define KWSPI_SMEMRDY		(1 << 1) /* SerMem Data xfer ready */
diff --git a/drivers/spi/kirkwood_spi.c b/drivers/spi/kirkwood_spi.c
index db8ba8b..0877915 100644
--- a/drivers/spi/kirkwood_spi.c
+++ b/drivers/spi/kirkwood_spi.c
@@ -88,11 +88,45 @@ void spi_free_slave(struct spi_slave *slave)
 
 int spi_claim_bus(struct spi_slave *slave)
 {
+	u32 config;
+	u32 spi_mpp_config[5];
+
+	config = CONFIG_SYS_KW_SPI_MPP;
+
+	if (config & CSn_MPP7)
+		spi_mpp_config[0] = MPP7_SPI_SCn;
+	else
+		spi_mpp_config[0] = MPP0_SPI_SCn;
+
+	if (config & MOSI_MPP6)
+		spi_mpp_config[1] = MPP6_SPI_MOSI;
+	else
+		spi_mpp_config[1] = MPP1_SPI_MOSI;
+
+	if (config & SCK_MPP10)
+		spi_mpp_config[2] = MPP10_SPI_SCK;
+	else
+		spi_mpp_config[2] = MPP2_SPI_SCK;
+
+	if (config & MISO_MPP11)
+		spi_mpp_config[3] = MPP11_SPI_MISO;
+	else
+		spi_mpp_config[3] = MPP3_SPI_MISO;
+
+	spi_mpp_config[4] = 0;
+
+	/* save current mpp configuration */
+	kirkwood_mpp_save();
+
+	/* finally set chosen mpp spi configuration */
+	kirkwood_mpp_conf(spi_mpp_config);
+
 	return 0;
 }
 
 void spi_release_bus(struct spi_slave *slave)
 {
+	kirkwood_mpp_restore();
 }
 
 #ifndef CONFIG_SPI_CS_IS_VALID
-- 
1.7.1