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
 15struct scu_gpio_priv {
 16	struct gpio_chip	chip;
 17	struct mutex		lock;
 18	struct device		*dev;
 19	struct imx_sc_ipc	*handle;
 20};
 21
 22static 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
 33static 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
 57static 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
 77static 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
 85static 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
117static const struct of_device_id imx_scu_gpio_dt_ids[] = {
118	{ .compatible = "fsl,imx8qxp-sc-gpio" },
119	{ /* sentinel */ }
120};
121
122static 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
130static int __init _imx_scu_gpio_init(void)
131{
132	return platform_driver_register(&imx_scu_gpio_driver);
133}
134
135subsys_initcall_sync(_imx_scu_gpio_init);
136
137MODULE_AUTHOR("Shenwei Wang <shenwei.wang@nxp.com>");
138MODULE_DESCRIPTION("NXP GPIO over IMX SCU API");
139MODULE_LICENSE("GPL");