spi: mediatek: add mtk_spi_compatible support

this patch adds max_fifo_size and must_rx compat support.
Signed-off-by: Leilk Liu <leilk.liu@mediatek.com>
Link: https://lore.kernel.org/r/20210322055244.30179-4-leilk.liu@mediatek.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-slave-mt27xx.c

@@ -10,6 +10,8 @@
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/spi/spi.h>
+#include <linux/of.h>
+
 
 #define SPIS_IRQ_EN_REG		0x0
 #define SPIS_IRQ_CLR_REG	0x4
@@ -61,8 +63,6 @@
 #define SPIS_DMA_ADDR_EN	BIT(1)
 #define SPIS_SOFT_RST		BIT(0)
 
-#define MTK_SPI_SLAVE_MAX_FIFO_SIZE 512U
-
 struct mtk_spi_slave {
 	struct device *dev;
 	void __iomem *base;
@@ -70,10 +70,19 @@ struct mtk_spi_slave {
 	struct completion xfer_done;
 	struct spi_transfer *cur_transfer;
 	bool slave_aborted;
+	const struct mtk_spi_compatible *dev_comp;
 };
 
+struct mtk_spi_compatible {
+	const u32 max_fifo_size;
+	bool must_rx;
+};
+static const struct mtk_spi_compatible mt2712_compat = {
+	.max_fifo_size = 512,
+};
 static const struct of_device_id mtk_spi_slave_of_match[] = {
-	{ .compatible = "mediatek,mt2712-spi-slave", },
+	{ .compatible = "mediatek,mt2712-spi-slave",
+	  .data = (void *)&mt2712_compat,},
 	{}
 };
 MODULE_DEVICE_TABLE(of, mtk_spi_slave_of_match);
@@ -272,7 +281,7 @@ static int mtk_spi_slave_transfer_one(struct spi_controller *ctlr,
 	mdata->slave_aborted = false;
 	mdata->cur_transfer = xfer;
 
-	if (xfer->len > MTK_SPI_SLAVE_MAX_FIFO_SIZE)
+	if (xfer->len > mdata->dev_comp->max_fifo_size)
 		return mtk_spi_slave_dma_transfer(ctlr, spi, xfer);
 	else
 		return mtk_spi_slave_fifo_transfer(ctlr, spi, xfer);
@@ -369,6 +378,7 @@ static int mtk_spi_slave_probe(struct platform_device *pdev)
 	struct spi_controller *ctlr;
 	struct mtk_spi_slave *mdata;
 	int irq, ret;
+	const struct of_device_id *of_id;
 
 	ctlr = spi_alloc_slave(&pdev->dev, sizeof(*mdata));
 	if (!ctlr) {
@@ -386,7 +396,17 @@ static int mtk_spi_slave_probe(struct platform_device *pdev)
 	ctlr->setup = mtk_spi_slave_setup;
 	ctlr->slave_abort = mtk_slave_abort;
 
+	of_id = of_match_node(mtk_spi_slave_of_match, pdev->dev.of_node);
+	if (!of_id) {
+		dev_err(&pdev->dev, "failed to probe of_node\n");
+		ret = -EINVAL;
+		goto err_put_ctlr;
+	}
 	mdata = spi_controller_get_devdata(ctlr);
+	mdata->dev_comp = of_id->data;
+
+	if (mdata->dev_comp->must_rx)
+		ctlr->flags = SPI_MASTER_MUST_RX;
 
 	platform_set_drvdata(pdev, ctlr);