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 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 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 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 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 }; 129 130 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