[PATCH v7 03/10] clk: realtek: Introduce a common probe()

[Yu-Chun Lin <eleanor.lin@realtek.com>]

From: Cheng-Yu Lee <cylee12@realtek.com>

Add rtk_clk_probe() to set up the shared regmap, register clock hardware,
and add the clock provider.

Additionally, if the "#reset-cells" property is present in the device tree,
it creates and registers an auxiliary device using the provided aux_name.
This allows the dedicated reset driver to bind to this device, enabling
both clock and reset drivers to share the same regmap.

Signed-off-by: Cheng-Yu Lee <cylee12@realtek.com>
Co-developed-by: Yu-Chun Lin <eleanor.lin@realtek.com>
Signed-off-by: Yu-Chun Lin <eleanor.lin@realtek.com>
---
 MAINTAINERS                  |  1 +
 drivers/clk/Kconfig          |  1 +
 drivers/clk/Makefile         |  1 +
 drivers/clk/realtek/Kconfig  | 28 +++++++++++++++
 drivers/clk/realtek/Makefile |  4 +++
 drivers/clk/realtek/common.c | 66 ++++++++++++++++++++++++++++++++++++
 drivers/clk/realtek/common.h | 37 ++++++++++++++++++++
 7 files changed, 138 insertions(+)
 create mode 100644 drivers/clk/realtek/Kconfig
 create mode 100644 drivers/clk/realtek/Makefile
 create mode 100644 drivers/clk/realtek/common.c
 create mode 100644 drivers/clk/realtek/common.h

diff --git a/MAINTAINERS b/MAINTAINERS
index ff0347f6556d..b16d2c62ea3d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22434,6 +22434,7 @@ L:	devicetree@vger.kernel.org
 L:	linux-clk@vger.kernel.org
 S:	Supported
 F:	Documentation/devicetree/bindings/clock/realtek*
+F:	drivers/clk/realtek/*
 F:	drivers/reset/realtek/*
 F:	include/dt-bindings/clock/realtek*
 F:	include/dt-bindings/reset/realtek*
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index b2efbe9f6acb..8bf262dd23a9 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -519,6 +519,7 @@ source "drivers/clk/nuvoton/Kconfig"
 source "drivers/clk/pistachio/Kconfig"
 source "drivers/clk/qcom/Kconfig"
 source "drivers/clk/ralink/Kconfig"
+source "drivers/clk/realtek/Kconfig"
 source "drivers/clk/renesas/Kconfig"
 source "drivers/clk/rockchip/Kconfig"
 source "drivers/clk/samsung/Kconfig"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index a3e2862ebd7e..e226bee2d039 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -140,6 +140,7 @@ obj-$(CONFIG_COMMON_CLK_PISTACHIO)	+= pistachio/
 obj-$(CONFIG_COMMON_CLK_PXA)		+= pxa/
 obj-$(CONFIG_COMMON_CLK_QCOM)		+= qcom/
 obj-y					+= ralink/
+obj-$(CONFIG_COMMON_CLK_REALTEK)	+= realtek/
 obj-y					+= renesas/
 obj-$(CONFIG_ARCH_ROCKCHIP)		+= rockchip/
 obj-$(CONFIG_COMMON_CLK_SAMSUNG)	+= samsung/
diff --git a/drivers/clk/realtek/Kconfig b/drivers/clk/realtek/Kconfig
new file mode 100644
index 000000000000..4e042e41f30d
--- /dev/null
+++ b/drivers/clk/realtek/Kconfig
@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config COMMON_CLK_REALTEK
+	tristate "Clock driver for Realtek SoCs"
+	depends on ARCH_REALTEK || COMPILE_TEST
+	default ARCH_REALTEK
+	help
+	  Enable the common clock framework infrastructure for Realtek
+	  system-on-chip platforms.
+
+	  This provides the base support required by individual Realtek
+	  clock controller drivers to expose clocks to peripheral devices.
+
+	  If you have a Realtek-based platform, say Y.
+
+if COMMON_CLK_REALTEK
+
+config RTK_CLK_COMMON
+	tristate "Realtek Clock Common"
+	select RESET_RTK_COMMON
+	select AUXILIARY_BUS
+	help
+	  Common helper code shared by Realtek clock controller drivers.
+
+	  This provides utility functions and data structures used by
+	  multiple Realtek clock implementations, and include integration
+	  with reset controllers where required.
+
+endif
diff --git a/drivers/clk/realtek/Makefile b/drivers/clk/realtek/Makefile
new file mode 100644
index 000000000000..377ec776ee47
--- /dev/null
+++ b/drivers/clk/realtek/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_RTK_CLK_COMMON) += clk-rtk.o
+
+clk-rtk-y += common.o
diff --git a/drivers/clk/realtek/common.c b/drivers/clk/realtek/common.c
new file mode 100644
index 000000000000..56f6ba1af6ef
--- /dev/null
+++ b/drivers/clk/realtek/common.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2019-2026 Realtek Semiconductor Corporation
+ * Author: Cheng-Yu Lee <cylee12@realtek.com>
+ */
+
+#include <linux/auxiliary_bus.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include "common.h"
+
+static int rtk_reset_controller_register(struct device *dev, const char *aux_name,
+					 struct regmap *map)
+{
+	struct auxiliary_device *adev;
+
+	if (!of_property_present(dev->of_node, "#reset-cells"))
+		return 0;
+
+	adev = devm_auxiliary_device_create(dev, aux_name, (void *)map);
+
+	if (IS_ERR(adev))
+		return PTR_ERR(adev);
+
+	return 0;
+}
+
+int rtk_clk_probe(struct platform_device *pdev, const struct rtk_clk_desc *desc,
+		  const char *aux_name)
+{
+	struct device *dev = &pdev->dev;
+	struct regmap *regmap;
+	int i, ret;
+
+	regmap = device_node_to_regmap(dev->of_node);
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap), "failed to get regmap\n");
+
+	for (i = 0; i < desc->num_clks; i++)
+		desc->clks[i]->regmap = regmap;
+
+	for (i = 0; i < desc->clk_data->num; i++) {
+		struct clk_hw *hw = desc->clk_data->hws[i];
+
+		if (!hw)
+			continue;
+
+		ret = devm_clk_hw_register(dev, hw);
+		if (ret)
+			return dev_err_probe(dev, ret, "failed to register hw of clk%d\n", i);
+	}
+
+	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
+					  desc->clk_data);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to add clock provider\n");
+
+	return rtk_reset_controller_register(dev, aux_name, regmap);
+}
+EXPORT_SYMBOL_NS_GPL(rtk_clk_probe, "REALTEK_CLK");
+
+MODULE_DESCRIPTION("Realtek clock infrastructure");
+MODULE_LICENSE("GPL");
diff --git a/drivers/clk/realtek/common.h b/drivers/clk/realtek/common.h
new file mode 100644
index 000000000000..c52fcdbff5ee
--- /dev/null
+++ b/drivers/clk/realtek/common.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2016-2026 Realtek Semiconductor Corporation
+ * Author: Cheng-Yu Lee <cylee12@realtek.com>
+ */
+
+#ifndef __CLK_REALTEK_COMMON_H
+#define __CLK_REALTEK_COMMON_H
+
+#include <linux/clk-provider.h>
+
+#define __clk_regmap_hw(_p) ((_p)->hw)
+
+struct device;
+struct platform_device;
+struct regmap;
+
+struct clk_regmap {
+	struct clk_hw hw;
+	struct regmap *regmap;
+};
+
+struct rtk_clk_desc {
+	struct clk_hw_onecell_data *clk_data;
+	struct clk_regmap * const *clks;
+	size_t num_clks;
+};
+
+static inline struct clk_regmap *to_clk_regmap(struct clk_hw *hw)
+{
+	return container_of(hw, struct clk_regmap, hw);
+}
+
+int rtk_clk_probe(struct platform_device *pdev, const struct rtk_clk_desc *desc,
+		  const char *aux_name);
+
+#endif /* __CLK_REALTEK_COMMON_H */
-- 
2.34.1