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(gc: 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(ipc: priv->handle,
47 resource: scu_rsrc_arr[offset], ctrl: 0, val: &level);
48 mutex_unlock(lock: &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(gc: 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(ipc: priv->handle,
70 resource: scu_rsrc_arr[offset], ctrl: 0, val: value);
71 mutex_unlock(lock: &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(dev: &pdev->dev, size: sizeof(*priv), GFP_KERNEL);
94 if (!priv)
95 return -ENOMEM;
96
97 ret = imx_scu_get_handle(ipc: &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, data: 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

source code of linux/drivers/gpio/gpio-imx-scu.c