| Loc Ho | 67778e0e | 2013-07-02 14:38:58 -0600 | [diff] [blame] | 1 | /* |
| 2 | * AppliedMicro X-Gene SoC Reboot Driver |
| 3 | * |
| 4 | * Copyright (c) 2013, Applied Micro Circuits Corporation |
| 5 | * Author: Feng Kan <fkan@apm.com> |
| 6 | * Author: Loc Ho <lho@apm.com> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License as |
| 10 | * published by the Free Software Foundation; either version 2 of |
| 11 | * the License, or (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| 21 | * MA 02111-1307 USA |
| 22 | * |
| 23 | * This driver provides system reboot functionality for APM X-Gene SoC. |
| 24 | * For system shutdown, this is board specify. If a board designer |
| 25 | * implements GPIO shutdown, use the gpio-poweroff.c driver. |
| 26 | */ |
| 27 | #include <linux/io.h> |
| 28 | #include <linux/of_device.h> |
| 29 | #include <linux/of_address.h> |
| 30 | #include <linux/platform_device.h> |
| 31 | #include <linux/stat.h> |
| 32 | #include <linux/slab.h> |
| 33 | #include <asm/system_misc.h> |
| 34 | |
| 35 | struct xgene_reboot_context { |
| 36 | struct platform_device *pdev; |
| 37 | void *csr; |
| 38 | u32 mask; |
| 39 | }; |
| 40 | |
| 41 | static struct xgene_reboot_context *xgene_restart_ctx; |
| 42 | |
| 43 | static void xgene_restart(char str, const char *cmd) |
| 44 | { |
| 45 | struct xgene_reboot_context *ctx = xgene_restart_ctx; |
| 46 | unsigned long timeout; |
| 47 | |
| 48 | /* Issue the reboot */ |
| 49 | if (ctx) |
| 50 | writel(ctx->mask, ctx->csr); |
| 51 | |
| 52 | timeout = jiffies + HZ; |
| 53 | while (time_before(jiffies, timeout)) |
| 54 | cpu_relax(); |
| 55 | |
| 56 | dev_emerg(&ctx->pdev->dev, "Unable to restart system\n"); |
| 57 | } |
| 58 | |
| 59 | static int xgene_reboot_probe(struct platform_device *pdev) |
| 60 | { |
| 61 | struct xgene_reboot_context *ctx; |
| 62 | |
| 63 | ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); |
| 64 | if (!ctx) { |
| 65 | dev_err(&pdev->dev, "out of memory for context\n"); |
| 66 | return -ENODEV; |
| 67 | } |
| 68 | |
| 69 | ctx->csr = of_iomap(pdev->dev.of_node, 0); |
| 70 | if (!ctx->csr) { |
| 71 | devm_kfree(&pdev->dev, ctx); |
| 72 | dev_err(&pdev->dev, "can not map resource\n"); |
| 73 | return -ENODEV; |
| 74 | } |
| 75 | |
| 76 | if (of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask)) |
| 77 | ctx->mask = 0xFFFFFFFF; |
| 78 | |
| 79 | ctx->pdev = pdev; |
| 80 | arm_pm_restart = xgene_restart; |
| 81 | xgene_restart_ctx = ctx; |
| 82 | |
| 83 | return 0; |
| 84 | } |
| 85 | |
| 86 | static struct of_device_id xgene_reboot_of_match[] = { |
| 87 | { .compatible = "apm,xgene-reboot" }, |
| 88 | {} |
| 89 | }; |
| 90 | |
| 91 | static struct platform_driver xgene_reboot_driver = { |
| 92 | .probe = xgene_reboot_probe, |
| 93 | .driver = { |
| 94 | .name = "xgene-reboot", |
| 95 | .of_match_table = xgene_reboot_of_match, |
| 96 | }, |
| 97 | }; |
| 98 | |
| 99 | static int __init xgene_reboot_init(void) |
| 100 | { |
| 101 | return platform_driver_register(&xgene_reboot_driver); |
| 102 | } |
| 103 | device_initcall(xgene_reboot_init); |