1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2021~2022 NXP
4 *
5 * The driver exports a standard gpiochip interface
6 * to control the PIN resources on SCU domain.
7 */
8
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/gpio/driver.h>
12#include <linux/platform_device.h>
13#include <linux/firmware/imx/svc/rm.h>
14#include <dt-bindings/firmware/imx/rsrc.h>
15
16struct scu_gpio_priv {
17	struct gpio_chip	chip;
18	struct mutex		lock;
19	struct device		*dev;
20	struct imx_sc_ipc	*handle;
21};
22
23static unsigned int scu_rsrc_arr[] = {
24	IMX_SC_R_BOARD_R0,
25	IMX_SC_R_BOARD_R1,
26	IMX_SC_R_BOARD_R2,
27	IMX_SC_R_BOARD_R3,
28	IMX_SC_R_BOARD_R4,
29	IMX_SC_R_BOARD_R5,
30	IMX_SC_R_BOARD_R6,
31	IMX_SC_R_BOARD_R7,
32};
33
34static int imx_scu_gpio_get(struct gpio_chip *chip, unsigned int offset)
35{
36	struct scu_gpio_priv *priv = gpiochip_get_data(chip);
37	int level;
38	int err;
39
40	if (offset >= chip->ngpio)
41		return -EINVAL;
42
43	mutex_lock(&priv->lock);
44
45	/* to read PIN state via scu api */
46	err = imx_sc_misc_get_control(priv->handle,
47			scu_rsrc_arr[offset], 0, &level);
48	mutex_unlock(&priv->lock);
49
50	if (err) {
51		dev_err(priv->dev, "SCU get failed: %d\n", err);
52		return err;
53	}
54
55	return level;
56}
57
58static void imx_scu_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
59{
60	struct scu_gpio_priv *priv = gpiochip_get_data(chip);
61	int err;
62
63	if (offset >= chip->ngpio)
64		return;
65
66	mutex_lock(&priv->lock);
67
68	/* to set PIN output level via scu api */
69	err = imx_sc_misc_set_control(priv->handle,
70			scu_rsrc_arr[offset], 0, value);
71	mutex_unlock(&priv->lock);
72
73	if (err)
74		dev_err(priv->dev, "SCU set (%d) failed: %d\n",
75				scu_rsrc_arr[offset], err);
76}
77
78static int imx_scu_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
79{
80	if (offset >= chip->ngpio)
81		return -EINVAL;
82
83	return GPIO_LINE_DIRECTION_OUT;
84}
85
86static int imx_scu_gpio_probe(struct platform_device *pdev)
87{
88	struct device *dev = &pdev->dev;
89	struct scu_gpio_priv *priv;
90	struct gpio_chip *gc;
91	int ret;
92
93	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
94	if (!priv)
95		return -ENOMEM;
96
97	ret = imx_scu_get_handle(&priv->handle);
98	if (ret)
99		return ret;
100
101	priv->dev = dev;
102	mutex_init(&priv->lock);
103
104	gc = &priv->chip;
105	gc->base = -1;
106	gc->parent = dev;
107	gc->ngpio = ARRAY_SIZE(scu_rsrc_arr);
108	gc->label = dev_name(dev);
109	gc->get = imx_scu_gpio_get;
110	gc->set = imx_scu_gpio_set;
111	gc->get_direction = imx_scu_gpio_get_direction;
112
113	platform_set_drvdata(pdev, priv);
114
115	return devm_gpiochip_add_data(dev, gc, priv);
116}
117
118static const struct of_device_id imx_scu_gpio_dt_ids[] = {
119	{ .compatible = "fsl,imx8qxp-sc-gpio" },
120	{ /* sentinel */ }
121};
122
123static struct platform_driver imx_scu_gpio_driver = {
124	.driver	= {
125		.name = "gpio-imx-scu",
126		.of_match_table = imx_scu_gpio_dt_ids,
127	},
128	.probe = imx_scu_gpio_probe,
129};
130
131static int __init _imx_scu_gpio_init(void)
132{
133	return platform_driver_register(&imx_scu_gpio_driver);
134}
135
136subsys_initcall_sync(_imx_scu_gpio_init);
137
138MODULE_AUTHOR("Shenwei Wang <shenwei.wang@nxp.com>");
139MODULE_DESCRIPTION("NXP GPIO over IMX SCU API");
140