gpio-imx-scu.c

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