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