[PATCH 1/6] clk: sunxi: Add a dummy clock driver for the RTC

[Samuel Holland <samuel@sholland.org>]

The 32kHz clock ("LOSC") on sunxi SoCs is provided by the RTC. It is
used, among other things, by the XHCI controller in the H6. To be able
to call clk_get_bulk() on the XHCI controller, some device needs to
provide all referenced clocks.

Since LOSC is a fixed-rate always-on clock, implementation is trivial.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---
 drivers/clk/sunxi/Makefile        |  2 ++
 drivers/clk/sunxi/clk_sun6i_rtc.c | 35 +++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)
 create mode 100644 drivers/clk/sunxi/clk_sun6i_rtc.c

diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
index 0dfc0593fb1..4f9282a8b9b 100644
--- a/drivers/clk/sunxi/Makefile
+++ b/drivers/clk/sunxi/Makefile
@@ -6,6 +6,8 @@
 
 obj-$(CONFIG_CLK_SUNXI) += clk_sunxi.o
 
+obj-$(CONFIG_CLK_SUNXI) += clk_sun6i_rtc.o
+
 obj-$(CONFIG_CLK_SUN4I_A10) += clk_a10.o
 obj-$(CONFIG_CLK_SUN5I_A10S) += clk_a10s.o
 obj-$(CONFIG_CLK_SUN6I_A31) += clk_a31.o
diff --git a/drivers/clk/sunxi/clk_sun6i_rtc.c b/drivers/clk/sunxi/clk_sun6i_rtc.c
new file mode 100644
index 00000000000..0c280d221ba
--- /dev/null
+++ b/drivers/clk/sunxi/clk_sun6i_rtc.c
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright (C) 2018 Amarula Solutions.
+ * Copyright (C) 2020 Samuel Holland <samuel@sholland.org>
+ */
+
+#include <clk-uclass.h>
+#include <dm.h>
+
+static int clk_sun6i_rtc_enable(struct clk *clk)
+{
+	return 0;
+}
+
+static const struct clk_ops clk_sun6i_rtc_ops = {
+	.enable = clk_sun6i_rtc_enable,
+};
+
+static const struct udevice_id sun6i_rtc_ids[] = {
+	{ .compatible = "allwinner,sun6i-a31-rtc" },
+	{ .compatible = "allwinner,sun8i-a23-rtc" },
+	{ .compatible = "allwinner,sun8i-h3-rtc" },
+	{ .compatible = "allwinner,sun8i-r40-rtc" },
+	{ .compatible = "allwinner,sun8i-v3-rtc" },
+	{ .compatible = "allwinner,sun50i-h5-rtc" },
+	{ .compatible = "allwinner,sun50i-h6-rtc" },
+	{ }
+};
+
+U_BOOT_DRIVER(clk_sun6i_rtc) = {
+	.name		= "clk_sun6i_rtc",
+	.id		= UCLASS_CLK,
+	.of_match	= sun6i_rtc_ids,
+	.ops		= &clk_sun6i_rtc_ops,
+};
-- 
2.26.2