spi: rzv2h-rspi: make FIFO size chip-specific

The Renesas RZ/T2H (R9A09G077) and RZ/N2H (R9A09G087) SoCs have a
different FIFO size compared to RZ/V2H. Add a chip-specific structure,
and set the FIFO size inside it, to prepare for adding support for them.

Signed-off-by: Cosmin Tanislav <cosmin-gabriel.tanislav.xa@renesas.com>
Link: https://patch.msgid.link/20251119161434.595677-3-cosmin-gabriel.tanislav.xa@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: Demon000

drivers/spi/spi-rzv2h-rspi.c

@@ -58,7 +58,6 @@
 /* Register SPDCR2 */
 #define RSPI_SPDCR2_TTRG	GENMASK(11, 8)
 #define RSPI_SPDCR2_RTRG	GENMASK(3, 0)
-#define RSPI_FIFO_SIZE		16
 
 /* Register SPSR */
 #define RSPI_SPSR_SPRF		BIT(15)
@@ -69,9 +68,14 @@
 #define RSPI_RESET_NUM		2
 #define RSPI_CLK_NUM		3
 
+struct rzv2h_rspi_info {
+	unsigned int fifo_size;
+};
+
 struct rzv2h_rspi_priv {
 	struct reset_control_bulk_data resets[RSPI_RESET_NUM];
 	struct spi_controller *controller;
+	const struct rzv2h_rspi_info *info;
 	void __iomem *base;
 	struct clk *tclk;
 	wait_queue_head_t wait;
@@ -305,7 +309,7 @@ static int rzv2h_rspi_prepare_message(struct spi_controller *ctlr,
 		writeb(0, rspi->base + RSPI_SSLP);
 
 	/* Setup FIFO thresholds */
-	conf16 = FIELD_PREP(RSPI_SPDCR2_TTRG, RSPI_FIFO_SIZE - 1);
+	conf16 = FIELD_PREP(RSPI_SPDCR2_TTRG, rspi->info->fifo_size - 1);
 	conf16 |= FIELD_PREP(RSPI_SPDCR2_RTRG, 0);
 	writew(conf16, rspi->base + RSPI_SPDCR2);
 
@@ -362,6 +366,8 @@ static int rzv2h_rspi_probe(struct platform_device *pdev)
 
 	rspi->controller = controller;
 
+	rspi->info = device_get_match_data(dev);
+
 	rspi->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(rspi->base))
 		return PTR_ERR(rspi->base);
@@ -445,8 +451,12 @@ static void rzv2h_rspi_remove(struct platform_device *pdev)
 	reset_control_bulk_assert(RSPI_RESET_NUM, rspi->resets);
 }
 
+static const struct rzv2h_rspi_info rzv2h_info = {
+	.fifo_size = 16,
+};
+
 static const struct of_device_id rzv2h_rspi_match[] = {
-	{ .compatible = "renesas,r9a09g057-rspi" },
+	{ .compatible = "renesas,r9a09g057-rspi", &rzv2h_info },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, rzv2h_rspi_match);