[PATCH v4 22/26] clk: sunxi-ng: ccu: add Display Engine 3.3 (DE33) support

[Ryan Walklin <ryan@testtoast.com>]

The DE33 is a newer version of the Allwinner Display Engine IP block,
found in the H616, H618, H700 and T507 SoCs. DE2 and DE3 are already
supported by the mainline driver.

The DE33 in the H616 has mixer0 and writeback units. The clocks
and resets required are identical to the H3 and H5 respectively, so use
those existing structs for the H616 description.

There are two additional 32-bit registers (at offsets 0x24 and 0x28)
which require clearing and setting respectively to bring up the
hardware. The function of these registers is currently unknown, and the
values are taken from the out-of-tree driver.

Add the required clock description struct and compatible string to the
DE2 driver.

Signed-off-by: Ryan Walklin <ryan@testtoast.com>

--
Changelog v2..v3:
- Lowercase hex value

Changelog v2..v3:
- Correct #include for writel()
---
 drivers/clk/sunxi-ng/ccu-sun8i-de2.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-de2.c b/drivers/clk/sunxi-ng/ccu-sun8i-de2.c
index 7683ea08d8e30..2eb5bb2547e92 100644
--- a/drivers/clk/sunxi-ng/ccu-sun8i-de2.c
+++ b/drivers/clk/sunxi-ng/ccu-sun8i-de2.c
@@ -5,6 +5,7 @@
 
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
+#include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
@@ -239,6 +240,16 @@ static const struct sunxi_ccu_desc sun50i_h5_de2_clk_desc = {
 	.num_resets	= ARRAY_SIZE(sun50i_h5_de2_resets),
 };
 
+static const struct sunxi_ccu_desc sun50i_h616_de33_clk_desc = {
+	.ccu_clks	= sun8i_de2_ccu_clks,
+	.num_ccu_clks	= ARRAY_SIZE(sun8i_de2_ccu_clks),
+
+	.hw_clks	= &sun8i_h3_de2_hw_clks,
+
+	.resets		= sun50i_h5_de2_resets,
+	.num_resets	= ARRAY_SIZE(sun50i_h5_de2_resets),
+};
+
 static int sunxi_de2_clk_probe(struct platform_device *pdev)
 {
 	struct clk *bus_clk, *mod_clk;
@@ -290,6 +301,16 @@ static int sunxi_de2_clk_probe(struct platform_device *pdev)
 			"Couldn't deassert reset control: %d\n", ret);
 		goto err_disable_mod_clk;
 	}
+ 
+	/*
+	 * The DE33 requires these additional (unknown) registers set
+	 * during initialisation.
+	 */
+	if (of_device_is_compatible(pdev->dev.of_node,
+				    "allwinner,sun50i-h616-de33-clk")) {
+		writel(0, reg + 0x24);
+		writel(0x0000a980, reg + 0x28);
+	}
 
 	ret = devm_sunxi_ccu_probe(&pdev->dev, reg, ccu_desc);
 	if (ret)
@@ -335,6 +356,10 @@ static const struct of_device_id sunxi_de2_clk_ids[] = {
 		.compatible = "allwinner,sun50i-h6-de3-clk",
 		.data = &sun50i_h5_de2_clk_desc,
 	},
+	{
+		.compatible = "allwinner,sun50i-h616-de33-clk",
+		.data = &sun50i_h616_de33_clk_desc,
+	},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sunxi_de2_clk_ids);
-- 
2.46.1