1 // SPDX-License-Identifier: GPL-2.0-only 2 // Copyright (C) 2013 Broadcom Corporation 3 4 #include <linux/bitops.h> 5 #include <linux/device.h> 6 #include <linux/errno.h> 7 #include <linux/init.h> 8 #include <linux/io.h> 9 #include <linux/jiffies.h> 10 #include <linux/notifier.h> 11 #include <linux/of_address.h> 12 #include <linux/of_irq.h> 13 #include <linux/of_platform.h> 14 #include <linux/platform_device.h> 15 #include <linux/printk.h> 16 #include <linux/reboot.h> 17 #include <linux/regmap.h> 18 #include <linux/smp.h> 19 #include <linux/mfd/syscon.h> 20 21 #define RESET_SOURCE_ENABLE_REG 1 22 #define SW_MASTER_RESET_REG 2 23 24 static struct regmap *regmap; 25 static u32 rst_src_en; 26 static u32 sw_mstr_rst; 27 28 struct reset_reg_mask { 29 u32 rst_src_en_mask; 30 u32 sw_mstr_rst_mask; 31 }; 32 33 static const struct reset_reg_mask *reset_masks; 34 35 static int brcmstb_restart_handler(struct notifier_block *this, 36 unsigned long mode, void *cmd) 37 { 38 int rc; 39 u32 tmp; 40 41 rc = regmap_write(regmap, rst_src_en, reset_masks->rst_src_en_mask); 42 if (rc) { 43 pr_err("failed to write rst_src_en (%d)\n", rc); 44 return NOTIFY_DONE; 45 } 46 47 rc = regmap_read(regmap, rst_src_en, &tmp); 48 if (rc) { 49 pr_err("failed to read rst_src_en (%d)\n", rc); 50 return NOTIFY_DONE; 51 } 52 53 rc = regmap_write(regmap, sw_mstr_rst, reset_masks->sw_mstr_rst_mask); 54 if (rc) { 55 pr_err("failed to write sw_mstr_rst (%d)\n", rc); 56 return NOTIFY_DONE; 57 } 58 59 rc = regmap_read(regmap, sw_mstr_rst, &tmp); 60 if (rc) { 61 pr_err("failed to read sw_mstr_rst (%d)\n", rc); 62 return NOTIFY_DONE; 63 } 64 65 while (1) 66 ; 67 68 return NOTIFY_DONE; 69 } 70 71 static struct notifier_block brcmstb_restart_nb = { 72 .notifier_call = brcmstb_restart_handler, 73 .priority = 128, 74 }; 75 76 static const struct reset_reg_mask reset_bits_40nm = { 77 .rst_src_en_mask = BIT(0), 78 .sw_mstr_rst_mask = BIT(0), 79 }; 80 81 static const struct reset_reg_mask reset_bits_65nm = { 82 .rst_src_en_mask = BIT(3), 83 .sw_mstr_rst_mask = BIT(31), 84 }; 85 86 static const struct of_device_id of_match[] = { 87 { .compatible = "brcm,brcmstb-reboot", .data = &reset_bits_40nm }, 88 { .compatible = "brcm,bcm7038-reboot", .data = &reset_bits_65nm }, 89 {}, 90 }; 91 92 static int brcmstb_reboot_probe(struct platform_device *pdev) 93 { 94 int rc; 95 struct device_node *np = pdev->dev.of_node; 96 const struct of_device_id *of_id; 97 98 of_id = of_match_node(of_match, np); 99 if (!of_id) { 100 pr_err("failed to look up compatible string\n"); 101 return -EINVAL; 102 } 103 reset_masks = of_id->data; 104 105 regmap = syscon_regmap_lookup_by_phandle(np, "syscon"); 106 if (IS_ERR(regmap)) { 107 pr_err("failed to get syscon phandle\n"); 108 return -EINVAL; 109 } 110 111 rc = of_property_read_u32_index(np, "syscon", RESET_SOURCE_ENABLE_REG, 112 &rst_src_en); 113 if (rc) { 114 pr_err("can't get rst_src_en offset (%d)\n", rc); 115 return -EINVAL; 116 } 117 118 rc = of_property_read_u32_index(np, "syscon", SW_MASTER_RESET_REG, 119 &sw_mstr_rst); 120 if (rc) { 121 pr_err("can't get sw_mstr_rst offset (%d)\n", rc); 122 return -EINVAL; 123 } 124 125 rc = register_restart_handler(&brcmstb_restart_nb); 126 if (rc) 127 dev_err(&pdev->dev, 128 "cannot register restart handler (err=%d)\n", rc); 129 130 return rc; 131 } 132 133 static struct platform_driver brcmstb_reboot_driver = { 134 .probe = brcmstb_reboot_probe, 135 .driver = { 136 .name = "brcmstb-reboot", 137 .of_match_table = of_match, 138 }, 139 }; 140 141 static int __init brcmstb_reboot_init(void) 142 { 143 return platform_driver_probe(&brcmstb_reboot_driver, 144 brcmstb_reboot_probe); 145 } 146 subsys_initcall(brcmstb_reboot_init); 147