[PATCH 2/2] spi/pxa2xx: enable multiblock DMA transfers for LPSS devices

From: Mika Westerberg
Date: Tue Mar 05 2013 - 05:03:48 EST


Intel LPSS SPI controllers need to have bit 0 (disable_ssp_dma_finish) set
in SSP_REG in order to properly perform DMA transfers spanning over
multiple blocks.

Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
drivers/spi/spi-pxa2xx.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 90b27a3..c6d5b97 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -68,6 +68,7 @@ MODULE_ALIAS("platform:pxa2xx-spi");
#define LPSS_TX_HITHRESH_DFLT 224

/* Offset from drv_data->lpss_base */
+#define SSP_REG 0x0c
#define SPI_CS_CONTROL 0x18
#define SPI_CS_CONTROL_SW_MODE BIT(0)
#define SPI_CS_CONTROL_CS_HIGH BIT(1)
@@ -138,6 +139,10 @@ detection_done:
/* Enable software chip select control */
value = SPI_CS_CONTROL_SW_MODE | SPI_CS_CONTROL_CS_HIGH;
__lpss_ssp_write_priv(drv_data, SPI_CS_CONTROL, value);
+
+ /* Enable multiblock DMA transfers */
+ if (drv_data->master_info->enable_dma)
+ __lpss_ssp_write_priv(drv_data, SSP_REG, 1);
}

static void lpss_ssp_cs_control(struct driver_data *drv_data, bool enable)
--
1.7.10.4

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