clk: thead: Port clock controller driver of TH1520 SoC

The driver is adapted from Linux kernel's version of clk-th1520-ap.c,
with only output clocks for external sensors, which are barely useful in
bootloaders, removed.

Same as the mainline driver, it currently lacks of ability to enable and
reconfigure PLLs, which could be implemented later.

Signed-off-by: Yao Zi <ziyao@disroot.org>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>

drivers/clk/Kconfig

@@ -271,6 +271,7 @@ source "drivers/clk/starfive/Kconfig"
 source "drivers/clk/stm32/Kconfig"
 source "drivers/clk/tegra/Kconfig"
 source "drivers/clk/ti/Kconfig"
+source "drivers/clk/thead/Kconfig"
 source "drivers/clk/uniphier/Kconfig"
 
 endmenu

drivers/clk/Makefile

@@ -20,6 +20,7 @@ obj-y += imx/
 obj-$(CONFIG_CLK_JH7110) += starfive/
 obj-y += tegra/
 obj-y += ti/
+obj-$(CONFIG_CLK_THEAD) += thead/
 obj-$(CONFIG_$(PHASE_)CLK_INTEL) += intel/
 obj-$(CONFIG_ARCH_ASPEED) += aspeed/
 obj-$(CONFIG_ARCH_MEDIATEK) += mediatek/

drivers/clk/thead/Kconfig

@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (c) 2025, Yao Zi <ziyao@disroot.org>
+
+config CLK_THEAD
+	bool "Clock support for T-Head SoCs"
+	depends on CLK
+
+if CLK_THEAD
+
+config CLK_THEAD_TH1520_AP
+	bool "T-Head TH1520 AP clock support"
+	select CLK_CCF
+	default THEAD_TH1520
+	help
+	  This enables support clock driver for T-Head TH1520 Application
+	  processor.
+
+endif

drivers/clk/thead/Makefile

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (C) 2025 Yao Zi <ziyao@disroot.org>
+
+obj-$(CONFIG_CLK_THEAD_TH1520_AP) += clk-th1520-ap.o