1 /* 2 * Copyright (C) 2013 Broadcom Corporation 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/device.h> 15 #include <linux/errno.h> 16 #include <linux/init.h> 17 #include <linux/io.h> 18 #include <linux/jiffies.h> 19 #include <linux/notifier.h> 20 #include <linux/of_address.h> 21 #include <linux/of_irq.h> 22 #include <linux/of_platform.h> 23 #include <linux/platform_device.h> 24 #include <linux/printk.h> 25 #include <linux/reboot.h> 26 #include <linux/regmap.h> 27 #include <linux/smp.h> 28 #include <linux/mfd/syscon.h> 29 30 #define RESET_SOURCE_ENABLE_REG 1 31 #define SW_MASTER_RESET_REG 2 32 33 static struct regmap *regmap; 34 static u32 rst_src_en; 35 static u32 sw_mstr_rst; 36 37 static int brcmstb_restart_handler(struct notifier_block *this, 38 unsigned long mode, void *cmd) 39 { 40 int rc; 41 u32 tmp; 42 43 rc = regmap_write(regmap, rst_src_en, 1); 44 if (rc) { 45 pr_err("failed to write rst_src_en (%d)\n", rc); 46 return NOTIFY_DONE; 47 } 48 49 rc = regmap_read(regmap, rst_src_en, &tmp); 50 if (rc) { 51 pr_err("failed to read rst_src_en (%d)\n", rc); 52 return NOTIFY_DONE; 53 } 54 55 rc = regmap_write(regmap, sw_mstr_rst, 1); 56 if (rc) { 57 pr_err("failed to write sw_mstr_rst (%d)\n", rc); 58 return NOTIFY_DONE; 59 } 60 61 rc = regmap_read(regmap, sw_mstr_rst, &tmp); 62 if (rc) { 63 pr_err("failed to read sw_mstr_rst (%d)\n", rc); 64 return NOTIFY_DONE; 65 } 66 67 while (1) 68 ; 69 70 return NOTIFY_DONE; 71 } 72 73 static struct notifier_block brcmstb_restart_nb = { 74 .notifier_call = brcmstb_restart_handler, 75 .priority = 128, 76 }; 77 78 static int brcmstb_reboot_probe(struct platform_device *pdev) 79 { 80 int rc; 81 struct device_node *np = pdev->dev.of_node; 82 83 regmap = syscon_regmap_lookup_by_phandle(np, "syscon"); 84 if (IS_ERR(regmap)) { 85 pr_err("failed to get syscon phandle\n"); 86 return -EINVAL; 87 } 88 89 rc = of_property_read_u32_index(np, "syscon", RESET_SOURCE_ENABLE_REG, 90 &rst_src_en); 91 if (rc) { 92 pr_err("can't get rst_src_en offset (%d)\n", rc); 93 return -EINVAL; 94 } 95 96 rc = of_property_read_u32_index(np, "syscon", SW_MASTER_RESET_REG, 97 &sw_mstr_rst); 98 if (rc) { 99 pr_err("can't get sw_mstr_rst offset (%d)\n", rc); 100 return -EINVAL; 101 } 102 103 rc = register_restart_handler(&brcmstb_restart_nb); 104 if (rc) 105 dev_err(&pdev->dev, 106 "cannot register restart handler (err=%d)\n", rc); 107 108 return rc; 109 } 110 111 static const struct of_device_id of_match[] = { 112 { .compatible = "brcm,brcmstb-reboot", }, 113 {}, 114 }; 115 116 static struct platform_driver brcmstb_reboot_driver = { 117 .probe = brcmstb_reboot_probe, 118 .driver = { 119 .name = "brcmstb-reboot", 120 .of_match_table = of_match, 121 }, 122 }; 123 124 static int __init brcmstb_reboot_init(void) 125 { 126 return platform_driver_probe(&brcmstb_reboot_driver, 127 brcmstb_reboot_probe); 128 } 129 subsys_initcall(brcmstb_reboot_init); 130