1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd 4 */ 5 6 #include <linux/init.h> 7 #include <linux/module.h> 8 #include <linux/kernel.h> 9 #include <linux/of.h> 10 #include <linux/platform_device.h> 11 #include <linux/reboot.h> 12 #include <linux/regmap.h> 13 #include <linux/mfd/syscon.h> 14 #include <linux/reboot-mode.h> 15 16 struct syscon_reboot_mode { 17 struct regmap *map; 18 struct reboot_mode_driver reboot; 19 u32 offset; 20 u32 mask; 21 }; 22 23 static int syscon_reboot_mode_write(struct reboot_mode_driver *reboot, 24 unsigned int magic) 25 { 26 struct syscon_reboot_mode *syscon_rbm; 27 int ret; 28 29 syscon_rbm = container_of(reboot, struct syscon_reboot_mode, reboot); 30 31 ret = regmap_update_bits(syscon_rbm->map, syscon_rbm->offset, 32 syscon_rbm->mask, magic); 33 if (ret < 0) 34 dev_err(reboot->dev, "update reboot mode bits failed\n"); 35 36 return ret; 37 } 38 39 static int syscon_reboot_mode_probe(struct platform_device *pdev) 40 { 41 int ret; 42 struct syscon_reboot_mode *syscon_rbm; 43 44 syscon_rbm = devm_kzalloc(&pdev->dev, sizeof(*syscon_rbm), GFP_KERNEL); 45 if (!syscon_rbm) 46 return -ENOMEM; 47 48 syscon_rbm->reboot.dev = &pdev->dev; 49 syscon_rbm->reboot.write = syscon_reboot_mode_write; 50 syscon_rbm->mask = 0xffffffff; 51 52 syscon_rbm->map = syscon_node_to_regmap(pdev->dev.parent->of_node); 53 if (IS_ERR(syscon_rbm->map)) 54 return PTR_ERR(syscon_rbm->map); 55 56 if (of_property_read_u32(pdev->dev.of_node, "offset", 57 &syscon_rbm->offset)) 58 return -EINVAL; 59 60 of_property_read_u32(pdev->dev.of_node, "mask", &syscon_rbm->mask); 61 62 ret = devm_reboot_mode_register(&pdev->dev, &syscon_rbm->reboot); 63 if (ret) 64 dev_err(&pdev->dev, "can't register reboot mode\n"); 65 66 return ret; 67 } 68 69 static const struct of_device_id syscon_reboot_mode_of_match[] = { 70 { .compatible = "syscon-reboot-mode" }, 71 {} 72 }; 73 MODULE_DEVICE_TABLE(of, syscon_reboot_mode_of_match); 74 75 static struct platform_driver syscon_reboot_mode_driver = { 76 .probe = syscon_reboot_mode_probe, 77 .driver = { 78 .name = "syscon-reboot-mode", 79 .of_match_table = syscon_reboot_mode_of_match, 80 }, 81 }; 82 module_platform_driver(syscon_reboot_mode_driver); 83 84 MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com"); 85 MODULE_DESCRIPTION("SYSCON reboot mode driver"); 86 MODULE_LICENSE("GPL v2"); 87