reset: imx: Add SCU reset driver for i.MX8QXP and i.MX8QM

Add System Controller Firmware(SCU) reset driver for i.MX8QM and i.MX8QXP.
SCU Manage resets for peripherals such as MIPI CSI. Currently, support two
reset sources: IMX_SC_R_CSI_0 and IMX_SC_R_CSI_1.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250210-8qxp_camera-v3-2-324f5105accc@nxp.com
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

Author: nxpfrankli

drivers/reset/Kconfig

@@ -96,6 +96,13 @@ config RESET_HSDK
 	help
 	  This enables the reset controller driver for HSDK board.
 
+config RESET_IMX_SCU
+	tristate "i.MX8Q Reset Driver"
+	depends on IMX_SCU && HAVE_ARM_SMCCC
+	depends on (ARM64 && ARCH_MXC) || COMPILE_TEST
+	help
+          This enables the reset controller driver for i.MX8QM/i.MX8QXP
+
 config RESET_IMX7
 	tristate "i.MX7/8 Reset Driver"
 	depends on HAS_IOMEM

drivers/reset/Makefile

@@ -15,6 +15,7 @@ obj-$(CONFIG_RESET_BRCMSTB_RESCAL) += reset-brcmstb-rescal.o
 obj-$(CONFIG_RESET_EYEQ) += reset-eyeq.o
 obj-$(CONFIG_RESET_GPIO) += reset-gpio.o
 obj-$(CONFIG_RESET_HSDK) += reset-hsdk.o
+obj-$(CONFIG_RESET_IMX_SCU) += reset-imx-scu.o
 obj-$(CONFIG_RESET_IMX7) += reset-imx7.o
 obj-$(CONFIG_RESET_IMX8MP_AUDIOMIX) += reset-imx8mp-audiomix.o
 obj-$(CONFIG_RESET_INTEL_GW) += reset-intel-gw.o

drivers/reset/reset-imx-scu.c

@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2025 NXP
+ * Frank Li <Frank.Li@nxp.com>
+ */
+#include <linux/firmware/imx/svc/misc.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+
+#include <dt-bindings/firmware/imx/rsrc.h>
+
+struct imx_scu_reset {
+	struct reset_controller_dev rc;
+	struct imx_sc_ipc *ipc_handle;
+};
+
+static struct imx_scu_reset *to_imx_scu(struct reset_controller_dev *rc)
+{
+	return container_of(rc, struct imx_scu_reset, rc);
+}
+
+struct imx_scu_id_map {
+	u32 resource_id;
+	u32 command_id;
+};
+
+static const struct imx_scu_id_map imx_scu_id_map[] = {
+	{ IMX_SC_R_CSI_0, IMX_SC_C_MIPI_RESET },
+	{ IMX_SC_R_CSI_1, IMX_SC_C_MIPI_RESET },
+};
+
+static int imx_scu_reset_assert(struct reset_controller_dev *rc, unsigned long id)
+{
+	struct imx_scu_reset *priv = to_imx_scu(rc);
+
+	return imx_sc_misc_set_control(priv->ipc_handle, imx_scu_id_map[id].resource_id,
+				       imx_scu_id_map[id].command_id, true);
+}
+
+static const struct reset_control_ops imx_scu_reset_ops = {
+	.assert = imx_scu_reset_assert,
+};
+
+static int imx_scu_xlate(struct reset_controller_dev *rc, const struct of_phandle_args *reset_spec)
+{
+	int i;
+
+	for (i = 0; i < rc->nr_resets; i++)
+		if (reset_spec->args[0] == imx_scu_id_map[i].resource_id)
+			return i;
+
+	return -EINVAL;
+}
+
+static int imx_scu_reset_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct imx_scu_reset *priv;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, &priv->rc);
+
+	ret = imx_scu_get_handle(&priv->ipc_handle);
+	if (ret)
+		return dev_err_probe(dev, ret, "sc_misc_MIPI get ipc handle failed!\n");
+
+	priv->rc.ops = &imx_scu_reset_ops;
+	priv->rc.owner = THIS_MODULE;
+	priv->rc.of_node = dev->of_node;
+	priv->rc.of_reset_n_cells = 1;
+	priv->rc.of_xlate = imx_scu_xlate;
+	priv->rc.nr_resets = ARRAY_SIZE(imx_scu_id_map);
+
+	return devm_reset_controller_register(dev, &priv->rc);
+}
+
+static const struct of_device_id imx_scu_reset_ids[] = {
+	{ .compatible = "fsl,imx-scu-reset", },
+	{}
+};
+MODULE_DEVICE_TABLE(platform, imx_scu_reset_ids);
+
+static struct platform_driver imx_scu_reset_driver = {
+	.probe          = imx_scu_reset_probe,
+	.driver = {
+		.name = "scu-reset",
+		.of_match_table = imx_scu_reset_ids,
+	},
+};
+module_platform_driver(imx_scu_reset_driver);
+
+MODULE_AUTHOR("Frank Li <Frank.Li@nxp.com>");
+MODULE_DESCRIPTION("i.MX scu reset driver");
+MODULE_LICENSE("GPL");