drm/sun4i: dsi: Add a variant structure

Replace the ad-hoc calls to of_device_is_compatible() with a structure
describing the differences between variants. This is in preparation for
adding more variants to the driver.

Reviewed-by: Jernej Skrabec <[e-mail]>
Signed-off-by: Samuel Holland <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Maxime Ripard <[e-mail]>

drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c

···
 
 static int sun6i_dsi_probe(struct platform_device *pdev)
 {
+	const struct sun6i_dsi_variant *variant;
 	struct device *dev = &pdev->dev;
-	const char *bus_clk_name = NULL;
 	struct sun6i_dsi *dsi;
 	void __iomem *base;
 	int ret;
+
+	variant = device_get_match_data(dev);
+	if (!variant)
+		return -EINVAL;
 
 	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
 	if (!dsi)
···
 	dsi->dev = dev;
 	dsi->host.ops = &sun6i_dsi_host_ops;
 	dsi->host.dev = dev;
-
-	if (of_device_is_compatible(dev->of_node,
-				    "allwinner,sun6i-a31-mipi-dsi"))
-		bus_clk_name = "bus";
+	dsi->variant = variant;
 
 	base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(base)) {
···
 		return PTR_ERR(dsi->regs);
 	}
 
-	dsi->bus_clk = devm_clk_get(dev, bus_clk_name);
+	dsi->bus_clk = devm_clk_get(dev, variant->has_mod_clk ? "bus" : NULL);
 	if (IS_ERR(dsi->bus_clk))
 		return dev_err_probe(dev, PTR_ERR(dsi->bus_clk),
 				     "Couldn't get the DSI bus clock\n");
···
 	if (ret)
 		return ret;
 
-	if (of_device_is_compatible(dev->of_node,
-				    "allwinner,sun6i-a31-mipi-dsi")) {
+	if (variant->has_mod_clk) {
 		dsi->mod_clk = devm_clk_get(dev, "mod");
 		if (IS_ERR(dsi->mod_clk)) {
 			dev_err(dev, "Couldn't get the DSI mod clock\n");
 			ret = PTR_ERR(dsi->mod_clk);
 			goto err_attach_clk;
 		}
-	}
 
-	/*
-	 * In order to operate properly, that clock seems to be always
-	 * set to 297MHz.
-	 */
-	clk_set_rate_exclusive(dsi->mod_clk, 297000000);
+		/*
+		 * In order to operate properly, the module clock on the
+		 * A31 variant always seems to be set to 297MHz.
+		 */
+		if (variant->set_mod_clk)
+			clk_set_rate_exclusive(dsi->mod_clk, 297000000);
+	}
 
 	dsi->dphy = devm_phy_get(dev, "dphy");
 	if (IS_ERR(dsi->dphy)) {
···
 err_remove_dsi_host:
 	mipi_dsi_host_unregister(&dsi->host);
 err_unprotect_clk:
-	clk_rate_exclusive_put(dsi->mod_clk);
+	if (dsi->variant->has_mod_clk && dsi->variant->set_mod_clk)
+		clk_rate_exclusive_put(dsi->mod_clk);
 err_attach_clk:
 	regmap_mmio_detach_clk(dsi->regs);
 
···
 
 	component_del(&pdev->dev, &sun6i_dsi_ops);
 	mipi_dsi_host_unregister(&dsi->host);
-	clk_rate_exclusive_put(dsi->mod_clk);
+	if (dsi->variant->has_mod_clk && dsi->variant->set_mod_clk)
+		clk_rate_exclusive_put(dsi->mod_clk);
 
 	regmap_mmio_detach_clk(dsi->regs);
 
 	return 0;
 }
 
+static const struct sun6i_dsi_variant sun6i_a31_mipi_dsi_variant = {
+	.has_mod_clk	= true,
+	.set_mod_clk	= true,
+};
+
+static const struct sun6i_dsi_variant sun50i_a64_mipi_dsi_variant = {
+};
+
 static const struct of_device_id sun6i_dsi_of_table[] = {
-	{ .compatible = "allwinner,sun6i-a31-mipi-dsi" },
-	{ .compatible = "allwinner,sun50i-a64-mipi-dsi" },
+	{
+		.compatible	= "allwinner,sun6i-a31-mipi-dsi",
+		.data		= &sun6i_a31_mipi_dsi_variant,
+	},
+	{
+		.compatible	= "allwinner,sun50i-a64-mipi-dsi",
+		.data		= &sun50i_a64_mipi_dsi_variant,
+	},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sun6i_dsi_of_table);

drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h

···
 
 #define SUN6I_DSI_TCON_DIV	4
 
+struct sun6i_dsi_variant {
+	bool			has_mod_clk;
+	bool			set_mod_clk;
+};
+
 struct sun6i_dsi {
 	struct drm_connector	connector;
 	struct drm_encoder	encoder;
···
 	struct mipi_dsi_device	*device;
 	struct drm_device	*drm;
 	struct drm_panel	*panel;
+
+	const struct sun6i_dsi_variant *variant;
 };
 
 static inline struct sun6i_dsi *host_to_sun6i_dsi(struct mipi_dsi_host *host)