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/bitops.h> 15 #include <linux/device.h> 16 #include <linux/errno.h> 17 #include <linux/init.h> 18 #include <linux/io.h> 19 #include <linux/jiffies.h> 20 #include <linux/notifier.h> 21 #include <linux/of_address.h> 22 #include <linux/of_irq.h> 23 #include <linux/of_platform.h> 24 #include <linux/platform_device.h> 25 #include <linux/printk.h> 26 #include <linux/reboot.h> 27 #include <linux/regmap.h> 28 #include <linux/smp.h> 29 #include <linux/mfd/syscon.h> 30 31 #define RESET_SOURCE_ENABLE_REG 1 32 #define SW_MASTER_RESET_REG 2 33 34 static struct regmap *regmap; 35 static u32 rst_src_en; 36 static u32 sw_mstr_rst; 37 38 struct reset_reg_mask { 39 u32 rst_src_en_mask; 40 u32 sw_mstr_rst_mask; 41 }; 42 43 static const struct reset_reg_mask *reset_masks; 44 45 static int brcmstb_restart_handler(struct notifier_block *this, 46 unsigned long mode, void *cmd) 47 { 48 int rc; 49 u32 tmp; 50 51 rc = regmap_write(regmap, rst_src_en, reset_masks->rst_src_en_mask); 52 if (rc) { 53 pr_err("failed to write rst_src_en (%d)\n", rc); 54 return NOTIFY_DONE; 55 } 56 57 rc = regmap_read(regmap, rst_src_en, &tmp); 58 if (rc) { 59 pr_err("failed to read rst_src_en (%d)\n", rc); 60 return NOTIFY_DONE; 61 } 62 63 rc = regmap_write(regmap, sw_mstr_rst, reset_masks->sw_mstr_rst_mask); 64 if (rc) { 65 pr_err("failed to write sw_mstr_rst (%d)\n", rc); 66 return NOTIFY_DONE; 67 } 68 69 rc = regmap_read(regmap, sw_mstr_rst, &tmp); 70 if (rc) { 71 pr_err("failed to read sw_mstr_rst (%d)\n", rc); 72 return NOTIFY_DONE; 73 } 74 75 while (1) 76 ; 77 78 return NOTIFY_DONE; 79 } 80 81 static struct notifier_block brcmstb_restart_nb = { 82 .notifier_call = brcmstb_restart_handler, 83 .priority = 128, 84 }; 85 86 static const struct reset_reg_mask reset_bits_40nm = { 87 .rst_src_en_mask = BIT(0), 88 .sw_mstr_rst_mask = BIT(0), 89 }; 90 91 static const struct reset_reg_mask reset_bits_65nm = { 92 .rst_src_en_mask = BIT(3), 93 .sw_mstr_rst_mask = BIT(31), 94 }; 95 96 static const struct of_device_id of_match[] = { 97 { .compatible = "brcm,brcmstb-reboot", .data = &reset_bits_40nm }, 98 { .compatible = "brcm,bcm7038-reboot", .data = &reset_bits_65nm }, 99 {}, 100 }; 101 102 static int brcmstb_reboot_probe(struct platform_device *pdev) 103 { 104 int rc; 105 struct device_node *np = pdev->dev.of_node; 106 const struct of_device_id *of_id; 107 108 of_id = of_match_node(of_match, np); 109 if (!of_id) { 110 pr_err("failed to look up compatible string\n"); 111 return -EINVAL; 112 } 113 reset_masks = of_id->data; 114 115 regmap = syscon_regmap_lookup_by_phandle(np, "syscon"); 116 if (IS_ERR(regmap)) { 117 pr_err("failed to get syscon phandle\n"); 118 return -EINVAL; 119 } 120 121 rc = of_property_read_u32_index(np, "syscon", RESET_SOURCE_ENABLE_REG, 122 &rst_src_en); 123 if (rc) { 124 pr_err("can't get rst_src_en offset (%d)\n", rc); 125 return -EINVAL; 126 } 127 128 rc = of_property_read_u32_index(np, "syscon", SW_MASTER_RESET_REG, 129 &sw_mstr_rst); 130 if (rc) { 131 pr_err("can't get sw_mstr_rst offset (%d)\n", rc); 132 return -EINVAL; 133 } 134 135 rc = register_restart_handler(&brcmstb_restart_nb); 136 if (rc) 137 dev_err(&pdev->dev, 138 "cannot register restart handler (err=%d)\n", rc); 139 140 return rc; 141 } 142 143 static struct platform_driver brcmstb_reboot_driver = { 144 .probe = brcmstb_reboot_probe, 145 .driver = { 146 .name = "brcmstb-reboot", 147 .of_match_table = of_match, 148 }, 149 }; 150 151 static int __init brcmstb_reboot_init(void) 152 { 153 return platform_driver_probe(&brcmstb_reboot_driver, 154 brcmstb_reboot_probe); 155 } 156 subsys_initcall(brcmstb_reboot_init); 157