1 /* 2 * Renesas R-Mobile Reset Driver 3 * 4 * Copyright (C) 2014 Glider bvba 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file "COPYING" in the main directory of this archive 8 * for more details. 9 */ 10 11 #include <linux/io.h> 12 #include <linux/module.h> 13 #include <linux/notifier.h> 14 #include <linux/of_address.h> 15 #include <linux/platform_device.h> 16 #include <linux/printk.h> 17 #include <linux/reboot.h> 18 19 /* SYSC Register Bank 2 */ 20 #define RESCNT2 0x20 /* Reset Control Register 2 */ 21 22 /* Reset Control Register 2 */ 23 #define RESCNT2_PRES 0x80000000 /* Soft power-on reset */ 24 25 static void __iomem *sysc_base2; 26 27 static int rmobile_reset_handler(struct notifier_block *this, 28 unsigned long mode, void *cmd) 29 { 30 pr_debug("%s %lu\n", __func__, mode); 31 32 /* Let's assume we have acquired the HPB semaphore */ 33 writel(RESCNT2_PRES, sysc_base2 + RESCNT2); 34 35 return NOTIFY_DONE; 36 } 37 38 static struct notifier_block rmobile_reset_nb = { 39 .notifier_call = rmobile_reset_handler, 40 .priority = 192, 41 }; 42 43 static int rmobile_reset_probe(struct platform_device *pdev) 44 { 45 int error; 46 47 sysc_base2 = of_iomap(pdev->dev.of_node, 1); 48 if (!sysc_base2) 49 return -ENODEV; 50 51 error = register_restart_handler(&rmobile_reset_nb); 52 if (error) { 53 dev_err(&pdev->dev, 54 "cannot register restart handler (err=%d)\n", error); 55 goto fail_unmap; 56 } 57 58 return 0; 59 60 fail_unmap: 61 iounmap(sysc_base2); 62 return error; 63 } 64 65 static int rmobile_reset_remove(struct platform_device *pdev) 66 { 67 unregister_restart_handler(&rmobile_reset_nb); 68 iounmap(sysc_base2); 69 return 0; 70 } 71 72 static const struct of_device_id rmobile_reset_of_match[] = { 73 { .compatible = "renesas,sysc-rmobile", }, 74 { /* sentinel */ } 75 }; 76 MODULE_DEVICE_TABLE(of, rmobile_reset_of_match); 77 78 static struct platform_driver rmobile_reset_driver = { 79 .probe = rmobile_reset_probe, 80 .remove = rmobile_reset_remove, 81 .driver = { 82 .name = "rmobile_reset", 83 .of_match_table = rmobile_reset_of_match, 84 }, 85 }; 86 87 module_platform_driver(rmobile_reset_driver); 88 89 MODULE_DESCRIPTION("Renesas R-Mobile Reset Driver"); 90 MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>"); 91 MODULE_LICENSE("GPL v2"); 92