Add driver support for ESWIN eic7700 SoC reset controller

From: Xuyang Dong <[email protected]>

Add device tree binding documentation and header file for the ESWIN eic7700 reset controller module.

Signed-off-by Yifeng Huang <[email protected]>

Signed-off-by Xuyang Dong <[email protected]>

---
 .../bindings/reset/eswin,eic7700-reset.yaml   |  47 +++
 .../dt-bindings/reset/eswin,eic7700-reset.h   | 460 ++++++++++++++++++
 2 files changed, 517 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reset/eswin,eic7700-reset.yaml
 create mode 100644 include/dt-bindings/reset/eswin,eic7700-reset.h

From: Xuyang Dong <[email protected]>

Add device tree binding documentation and header file for the ESWIN eic7700 reset controller module.

Signed-off-by Yifeng Huang <[email protected]>

Signed-off-by Xuyang Dong <[email protected]>

---
 .../bindings/reset/eswin,eic7700-reset.yaml   |  47 +++
 .../dt-bindings/reset/eswin,eic7700-reset.h   | 460 ++++++++++++++++++
 2 files changed, 517 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reset/eswin,eic7700-reset.yaml
 create mode 100644 include/dt-bindings/reset/eswin,eic7700-reset.h

Documentation/devicetree/bindings/reset/eswin,eic7700-reset.yaml new file +35 -0

new file mode 100644
index 000000000000..1a3c6d230efe
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reset/eswin,eic7700-reset.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ESWIN EIC7700 SoC reset controller
+
+maintainers:
+  - Yifeng Huang <[email protected]>
+  - Xuyang Dong <[email protected]>
+
+description: |
+  The reset controller registers are part of the syscrg block on
+  the EIC7700 SoC.
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - const: eswin,eic7700-reset
+
+  '#reset-cells':
+    description: |
+      Specifies the number of cells needed to encode a reset source.
+      Cell #1 : module id of the reset consumer
+      Cell #2 : bit position of the reset in each reset consumer module
+    const: 2
+
+required:
+  - compatible
+  - '#reset-cells'
+
+additionalProperties: false
+

include/dt-bindings/reset/eswin,eic7700-reset.h new file +5 -0

new file mode 100644
index 000000000000..fcf004620db9
@@ -0,0 +1,460 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+/*
+ * Copyright 2024, Beijing ESWIN Computing Technology Co., Ltd.. All rights reserved.
+ *
+ * Device Tree binding constants for EIC7700 reset controller.

From: Xuyang Dong <[email protected]>

Add support for reset controller in eic7700 series chips. Provide functionality for asserting and deasserting resets on the chip.

Signed-off-by Yifeng Huang <[email protected]>

Signed-off-by Xuyang Dong <[email protected]>

---
 drivers/reset/Kconfig         |   9 ++
 drivers/reset/Makefile        |   1 +
 drivers/reset/reset-eic7700.c | 249 ++++++++++++++++++++++++++++++++++
 3 files changed, 259 insertions(+)
 create mode 100644 drivers/reset/reset-eic7700.c

drivers/reset/Kconfig +0 -0

index 99f6f9784e68..d6eef5358e13 100644

drivers/reset/Kconfig +8 -0

+	bool "Reset controller driver for Eswin SoCs"
+	default ARCH_ESWIN
+	help
+	  This enables the reset controller driver for Eswin SoCs. This driver is
+	  specific to Eswin SoCs and should only be enabled if using such hardware.
+	  The driver supports eic7700 series chips and provides functionality for
+	  asserting and deasserting resets on the chip.
+
 source "drivers/reset/amlogic/Kconfig"
 source "drivers/reset/starfive/Kconfig"
 source "drivers/reset/sti/Kconfig"

drivers/reset/Makefile +0 -0

index 31f9904d13f9..2210c4e55834 100644

drivers/reset/Makefile +8 -0

+	}
+
+	platform_set_drvdata(pdev, data);
+
+	data->rcdev.owner = THIS_MODULE;
+	data->rcdev.ops = &eswin_reset_ops;
+	data->rcdev.of_node = pdev->dev.of_node;
+	data->rcdev.of_reset_n_cells = 2;

drivers/reset/Makefile +15 -0

+
+	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
+}
+
+static void eswin_reset_remove(struct platform_device *pdev)
+{
+	struct eswin_reset_data *data = platform_get_drvdata(pdev);
+
+	idr_destroy(&data->idr);
+}
+
+static struct platform_driver eswin_reset_driver = {
+	.probe	= eswin_reset_probe,
+	.remove = eswin_reset_remove,
+	.driver = {

From: Xuyang Dong <dongxuyang-sYo9T6QOUuK8M3too/[email protected]>

Add support for reset controller in eic7700 series chips. Provide functionality for asserting and deasserting resets on the chip.

+#define CLEAR_BOOT_FLAG_BIT BIT_ULL(0)

drivers/reset/reset-eic7700.c new file +13 -0

+/**
+ * eswin_reset_set() - program a device's reset
+ * @rcdev: reset controller entity
+ * @id: ID of the reset to toggle
+ * @assert: boolean flag to indicate assert or deassert
+ *
+ * This is a common internal function used to assert or deassert a device's
+ * reset by clear and set the reset bit. The device's reset is asserted if the
+ * @assert argument is true, or deasserted if @assert argument is false.
+ *
+ * Return: 0 for successful request, else a corresponding error value
+ */
+static int eswin_reset_set(struct reset_controller_dev *rcdev, unsigned long id,

drivers/reset/reset-eic7700.c new file +5 -0

+
+	if (!control)
+		return -EINVAL;
+
+	if (assert) {

drivers/reset/reset-eic7700.c new file +17 -0

+	if (ret != 0)
+		return ret;
+
+	return 0;
+}
+
+static int eswin_reset_assert(struct reset_controller_dev *rcdev,
+			      unsigned long id)
+{
+	return eswin_reset_set(rcdev, id, true);
+}
+
+static int eswin_reset_deassert(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	return eswin_reset_set(rcdev, id, false);
+}

drivers/reset/reset-eic7700.c new file +20 -0

+		return 0;
+}
+
+/**
+ * eswin_reset_of_xlate() - translate a set of OF arguments to a reset ID
+ * @rcdev: reset controller entity
+ * @reset_spec: OF reset argument specifier
+ *
+ * This function performs the translation of the reset argument specifier
+ * values defined in a reset consumer device node. The function allocates a
+ * reset control structure for that device reset, and will be used by the
+ * driver for performing any reset functions on that reset. An idr structure
+ * is allocated and used to map to the reset control structure. This idr
+ * is used by the driver to do reset lookups.
+ *
+ * Return: 0 for successful request, else a corresponding error value
+ */
+static int eswin_reset_of_xlate(struct reset_controller_dev *rcdev,
+				const struct of_phandle_args *reset_spec)
+{

drivers/reset/reset-eic7700.c new file +7 -0

+		return ret;
+
+	control = devm_kzalloc(data->dev, sizeof(*control), GFP_KERNEL);
+	if (!control)
+		return -ENOMEM;
+
+	control->dev_id = reset_spec->args[0];

drivers/reset/reset-eic7700.c new file +25 -0

+};
+
+static int eswin_reset_probe(struct platform_device *pdev)
+{
+	struct eswin_reset_data *data;
+	struct device *parent;
+
+	parent = pdev->dev.parent;
+	if (!parent) {
+		dev_err(&pdev->dev, "no parent\n");
+		return -ENODEV;
+	}
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->regmap = syscon_node_to_regmap(parent->of_node);
+	if (IS_ERR(data->regmap)) {
+		dev_err(&pdev->dev, "failed to get parent regmap\n");
+		return PTR_ERR(data->regmap);
+	}
+
+	platform_set_drvdata(pdev, data);
+