spi: pxa2xx: Introduce DMA burst size support

Some masters may have different DMA burst size than hard coded default.
In such case respect the value given by DMA burst size provided via
platform data.

Signed-off-by: Andy Shevchenko <[e-mail]>
Tested-by: Jarkko Nikula <[e-mail]>
Reviewed-by: Jarkko Nikula <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

drivers/spi/spi-pxa2xx-dma.c

···
 					   u32 *threshold)
 {
 	struct pxa2xx_spi_chip *chip_info = spi->controller_data;
+	struct driver_data *drv_data = spi_controller_get_devdata(spi->controller);
+	u32 dma_burst_size = drv_data->controller_info->dma_burst_size;
 
 	/*
 	 * If the DMA burst size is given in chip_info we use that,
 	 * otherwise we use the default. Also we use the default FIFO
 	 * thresholds for now.
 	 */
-	*burst_code = chip_info ? chip_info->dma_burst_size : 1;
+	*burst_code = chip_info ? chip_info->dma_burst_size : dma_burst_size;
 	*threshold = SSCR1_RxTresh(RX_THRESH_DFLT)
 		   | SSCR1_TxTresh(TX_THRESH_DFLT);
 

drivers/spi/spi-pxa2xx-pci.c

···
 	void *tx_param;
 	void *rx_param;
 
+	int dma_burst_size;
+
 	int (*setup)(struct pci_dev *pdev, struct pxa_spi_info *c);
 };
 
···
 	rx->dma_dev = &dma_dev->dev;
 
 	c->dma_filter = lpss_dma_filter;
+	c->dma_burst_size = 8;
 	return 0;
 }
 
···
 	spi_pdata.tx_param = c->tx_param;
 	spi_pdata.rx_param = c->rx_param;
 	spi_pdata.enable_dma = c->rx_param && c->tx_param;
+	spi_pdata.dma_burst_size = c->dma_burst_size ? c->dma_burst_size : 1;
 
 	ssp = &spi_pdata.ssp;
 	ssp->phys_base = pci_resource_start(dev, 0);

drivers/spi/spi-pxa2xx.c

···
 	pdata->is_slave = of_property_read_bool(pdev->dev.of_node, "spi-slave");
 	pdata->num_chipselect = 1;
 	pdata->enable_dma = true;
+	pdata->dma_burst_size = 1;
 
 	return pdata;
 }

include/linux/spi/pxa2xx_spi.h

···
 struct pxa2xx_spi_controller {
 	u16 num_chipselect;
 	u8 enable_dma;
+	u8 dma_burst_size;
 	bool is_slave;
 
 	/* DMA engine specific config */