spi: spi-mtk-nor: improve device table for adding more capabilities

Define a structure for adding more capabilities.
Add a item extra_dummy_bit for new SoCs, due to design changed.
Signed-off-by: Guochun Mao <guochun.mao@mediatek.com>
Signed-off-by: Zhen Zhang <zhen.zhang@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220118142820.2729-3-guochun.mao@mediatek.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-mtk-nor.c

@@ -95,6 +95,17 @@
 
 #define CLK_TO_US(sp, clkcnt)		DIV_ROUND_UP(clkcnt, sp->spi_freq / 1000000)
 
+struct mtk_nor_caps {
+	u8 dma_bits;
+
+	/* extra_dummy_bit is adding for the IP of new SoCs.
+	 * Some new SoCs modify the timing of fetching registers' values
+	 * and IDs of nor flash, they need a extra_dummy_bit which can add
+	 * more clock cycles for fetching data.
+	 */
+	u8 extra_dummy_bit;
+};
+
 struct mtk_nor {
 	struct spi_controller *ctlr;
 	struct device *dev;
@@ -109,6 +120,7 @@ struct mtk_nor {
 	bool has_irq;
 	bool high_dma;
 	struct completion op_done;
+	const struct mtk_nor_caps *caps;
 };
 
 static inline void mtk_nor_rmw(struct mtk_nor *sp, u32 reg, u32 set, u32 clr)
@@ -554,7 +566,12 @@ static int mtk_nor_spi_mem_prg(struct mtk_nor *sp, const struct spi_mem_op *op)
 	}
 
 	// trigger op
-	writel(prg_len * BITS_PER_BYTE, sp->base + MTK_NOR_REG_PRG_CNT);
+	if (rx_len)
+		writel(prg_len * BITS_PER_BYTE + sp->caps->extra_dummy_bit,
+		       sp->base + MTK_NOR_REG_PRG_CNT);
+	else
+		writel(prg_len * BITS_PER_BYTE, sp->base + MTK_NOR_REG_PRG_CNT);
+
 	ret = mtk_nor_cmd_exec(sp, MTK_NOR_CMD_PROGRAM,
 			       prg_len * BITS_PER_BYTE);
 	if (ret)
@@ -743,9 +760,19 @@ static const struct spi_controller_mem_ops mtk_nor_mem_ops = {
 	.exec_op = mtk_nor_exec_op
 };
 
+const struct mtk_nor_caps mtk_nor_caps_mt8173 = {
+	.dma_bits = 32,
+	.extra_dummy_bit = 0,
+};
+
+const struct mtk_nor_caps mtk_nor_caps_mt8192 = {
+	.dma_bits = 36,
+	.extra_dummy_bit = 0,
+};
+
 static const struct of_device_id mtk_nor_match[] = {
-	{ .compatible = "mediatek,mt8192-nor", .data = (void *)36 },
-	{ .compatible = "mediatek,mt8173-nor", .data = (void *)32 },
+	{ .compatible = "mediatek,mt8173-nor", .data = &mtk_nor_caps_mt8173 },
+	{ .compatible = "mediatek,mt8192-nor", .data = &mtk_nor_caps_mt8192 },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, mtk_nor_match);
@@ -754,10 +781,10 @@ static int mtk_nor_probe(struct platform_device *pdev)
 {
 	struct spi_controller *ctlr;
 	struct mtk_nor *sp;
+	struct mtk_nor_caps *caps;
 	void __iomem *base;
 	struct clk *spi_clk, *ctlr_clk, *axi_clk;
 	int ret, irq;
-	unsigned long dma_bits;
 
 	base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(base))
@@ -775,10 +802,12 @@ static int mtk_nor_probe(struct platform_device *pdev)
 	if (IS_ERR(axi_clk))
 		return PTR_ERR(axi_clk);
 
-	dma_bits = (unsigned long)of_device_get_match_data(&pdev->dev);
-	if (dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(dma_bits))) {
-		dev_err(&pdev->dev, "failed to set dma mask(%lu)\n", dma_bits);
-		return -EINVAL;
+	caps = (struct mtk_nor_caps *)of_device_get_match_data(&pdev->dev);
+
+	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(caps->dma_bits));
+	if (ret) {
+		dev_err(&pdev->dev, "failed to set dma mask(%u)\n", caps->dma_bits);
+		return ret;
 	}
 
 	ctlr = devm_spi_alloc_master(&pdev->dev, sizeof(*sp));
@@ -808,7 +837,8 @@ static int mtk_nor_probe(struct platform_device *pdev)
 	sp->spi_clk = spi_clk;
 	sp->ctlr_clk = ctlr_clk;
 	sp->axi_clk = axi_clk;
-	sp->high_dma = (dma_bits > 32);
+	sp->caps = caps;
+	sp->high_dma = caps->dma_bits > 32;
 	sp->buffer = dmam_alloc_coherent(&pdev->dev,
 				MTK_NOR_BOUNCE_BUF_SIZE + MTK_NOR_DMA_ALIGN,
 				&sp->buffer_dma, GFP_KERNEL);