1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright 2025 NXP
4  * Frank Li <Frank.Li@nxp.com>
5  */
6 #include <linux/firmware/imx/svc/misc.h>
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/of.h>
10 #include <linux/platform_device.h>
11 #include <linux/reset-controller.h>
12 
13 #include <dt-bindings/firmware/imx/rsrc.h>
14 
15 struct imx_scu_reset {
16 	struct reset_controller_dev rc;
17 	struct imx_sc_ipc *ipc_handle;
18 };
19 
20 static struct imx_scu_reset *to_imx_scu(struct reset_controller_dev *rc)
21 {
22 	return container_of(rc, struct imx_scu_reset, rc);
23 }
24 
25 struct imx_scu_id_map {
26 	u32 resource_id;
27 	u32 command_id;
28 };
29 
30 static const struct imx_scu_id_map imx_scu_id_map[] = {
31 	{ IMX_SC_R_CSI_0, IMX_SC_C_MIPI_RESET },
32 	{ IMX_SC_R_CSI_1, IMX_SC_C_MIPI_RESET },
33 };
34 
35 static int imx_scu_reset_assert(struct reset_controller_dev *rc, unsigned long id)
36 {
37 	struct imx_scu_reset *priv = to_imx_scu(rc);
38 
39 	return imx_sc_misc_set_control(priv->ipc_handle, imx_scu_id_map[id].resource_id,
40 				       imx_scu_id_map[id].command_id, true);
41 }
42 
43 static const struct reset_control_ops imx_scu_reset_ops = {
44 	.assert = imx_scu_reset_assert,
45 };
46 
47 static int imx_scu_xlate(struct reset_controller_dev *rc, const struct of_phandle_args *reset_spec)
48 {
49 	int i;
50 
51 	for (i = 0; i < rc->nr_resets; i++)
52 		if (reset_spec->args[0] == imx_scu_id_map[i].resource_id)
53 			return i;
54 
55 	return -EINVAL;
56 }
57 
58 static int imx_scu_reset_probe(struct platform_device *pdev)
59 {
60 	struct device *dev = &pdev->dev;
61 	struct imx_scu_reset *priv;
62 	int ret;
63 
64 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
65 	if (!priv)
66 		return -ENOMEM;
67 
68 	platform_set_drvdata(pdev, &priv->rc);
69 
70 	ret = imx_scu_get_handle(&priv->ipc_handle);
71 	if (ret)
72 		return dev_err_probe(dev, ret, "sc_misc_MIPI get ipc handle failed!\n");
73 
74 	priv->rc.ops = &imx_scu_reset_ops;
75 	priv->rc.owner = THIS_MODULE;
76 	priv->rc.of_node = dev->of_node;
77 	priv->rc.of_reset_n_cells = 1;
78 	priv->rc.of_xlate = imx_scu_xlate;
79 	priv->rc.nr_resets = ARRAY_SIZE(imx_scu_id_map);
80 
81 	return devm_reset_controller_register(dev, &priv->rc);
82 }
83 
84 static const struct of_device_id imx_scu_reset_ids[] = {
85 	{ .compatible = "fsl,imx-scu-reset", },
86 	{}
87 };
88 MODULE_DEVICE_TABLE(of, imx_scu_reset_ids);
89 
90 static struct platform_driver imx_scu_reset_driver = {
91 	.probe          = imx_scu_reset_probe,
92 	.driver = {
93 		.name = "scu-reset",
94 		.of_match_table = imx_scu_reset_ids,
95 	},
96 };
97 module_platform_driver(imx_scu_reset_driver);
98 
99 MODULE_AUTHOR("Frank Li <Frank.Li@nxp.com>");
100 MODULE_DESCRIPTION("i.MX scu reset driver");
101 MODULE_LICENSE("GPL");
102