| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2016 Broadcom |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License as |
| 6 | * published by the Free Software Foundation version 2. |
| 7 | * |
| 8 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any |
| 9 | * kind, whether express or implied; without even the implied warranty |
| 10 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/io.h> |
| 15 | #include <linux/of_address.h> |
| 16 | #include <linux/of_platform.h> |
| 17 | #include <linux/reboot.h> |
| 18 | |
| 19 | #define RSTMGR_REG_WR_ACCESS_OFFSET 0 |
| 20 | #define RSTMGR_REG_CHIP_SOFT_RST_OFFSET 4 |
| 21 | |
| 22 | #define RSTMGR_WR_PASSWORD 0xa5a5 |
| 23 | #define RSTMGR_WR_PASSWORD_SHIFT 8 |
| 24 | #define RSTMGR_WR_ACCESS_ENABLE 1 |
| 25 | |
| 26 | static void __iomem *kona_reset_base; |
| 27 | |
| 28 | static int kona_reset_handler(struct notifier_block *this, |
| 29 | unsigned long mode, void *cmd) |
| 30 | { |
| 31 | /* |
| 32 | * A soft reset is triggered by writing a 0 to bit 0 of the soft reset |
| 33 | * register. To write to that register we must first write the password |
| 34 | * and the enable bit in the write access enable register. |
| 35 | */ |
| 36 | writel((RSTMGR_WR_PASSWORD << RSTMGR_WR_PASSWORD_SHIFT) | |
| 37 | RSTMGR_WR_ACCESS_ENABLE, |
| 38 | kona_reset_base + RSTMGR_REG_WR_ACCESS_OFFSET); |
| 39 | writel(0, kona_reset_base + RSTMGR_REG_CHIP_SOFT_RST_OFFSET); |
| 40 | |
| 41 | return NOTIFY_DONE; |
| 42 | } |
| 43 | |
| 44 | static struct notifier_block kona_reset_nb = { |
| 45 | .notifier_call = kona_reset_handler, |
| 46 | .priority = 128, |
| 47 | }; |
| 48 | |
| 49 | static int kona_reset_probe(struct platform_device *pdev) |
| 50 | { |
| 51 | struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 52 | |
| 53 | kona_reset_base = devm_ioremap_resource(&pdev->dev, res); |
| 54 | if (IS_ERR(kona_reset_base)) |
| 55 | return PTR_ERR(kona_reset_base); |
| 56 | |
| 57 | return register_restart_handler(&kona_reset_nb); |
| 58 | } |
| 59 | |
| 60 | static const struct of_device_id of_match[] = { |
| 61 | { .compatible = "brcm,bcm21664-resetmgr" }, |
| 62 | {}, |
| 63 | }; |
| 64 | |
| 65 | static struct platform_driver bcm_kona_reset_driver = { |
| 66 | .probe = kona_reset_probe, |
| 67 | .driver = { |
| 68 | .name = "brcm-kona-reset", |
| 69 | .of_match_table = of_match, |
| 70 | }, |
| 71 | }; |
| 72 | |
| 73 | builtin_platform_driver(bcm_kona_reset_driver); |