spi/pxa2xx: enable multiblock DMA transfers for LPSS devices

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@linux.intel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

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)