| Geert Uytterhoeven | fa0f8d6 | 2014-12-04 16:33:21 +0100 | [diff] [blame] | 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"); |