1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) 2 /* 3 * SP7021 reset driver 4 * 5 * Copyright (C) Sunplus Technology Co., Ltd. 6 * All rights reserved. 7 */ 8 9 #include <linux/io.h> 10 #include <linux/init.h> 11 #include <linux/platform_device.h> 12 #include <linux/reset-controller.h> 13 #include <linux/reboot.h> 14 15 /* HIWORD_MASK_REG BITS */ 16 #define BITS_PER_HWM_REG 16 17 18 /* resets HW info: reg_index_shift */ 19 static const u32 sp_resets[] = { 20 /* SP7021: mo_reset0 ~ mo_reset9 */ 21 0x00, 22 0x02, 23 0x03, 24 0x04, 25 0x05, 26 0x06, 27 0x07, 28 0x08, 29 0x09, 30 0x0a, 31 0x0b, 32 0x0d, 33 0x0e, 34 0x0f, 35 0x10, 36 0x12, 37 0x14, 38 0x15, 39 0x16, 40 0x17, 41 0x18, 42 0x19, 43 0x1a, 44 0x1b, 45 0x1c, 46 0x1d, 47 0x1e, 48 0x1f, 49 0x20, 50 0x21, 51 0x22, 52 0x23, 53 0x24, 54 0x25, 55 0x26, 56 0x2a, 57 0x2b, 58 0x2d, 59 0x2e, 60 0x30, 61 0x31, 62 0x32, 63 0x33, 64 0x3d, 65 0x3e, 66 0x3f, 67 0x42, 68 0x44, 69 0x4b, 70 0x4c, 71 0x4d, 72 0x4e, 73 0x4f, 74 0x50, 75 0x55, 76 0x60, 77 0x61, 78 0x6a, 79 0x6f, 80 0x70, 81 0x73, 82 0x74, 83 0x86, 84 0x8a, 85 0x8b, 86 0x8d, 87 0x8e, 88 0x8f, 89 0x90, 90 0x92, 91 0x93, 92 0x94, 93 0x95, 94 0x96, 95 0x97, 96 0x98, 97 0x99, 98 }; 99 100 struct sp_reset { 101 struct reset_controller_dev rcdev; 102 void __iomem *base; 103 }; 104 105 static inline struct sp_reset *to_sp_reset(struct reset_controller_dev *rcdev) 106 { 107 return container_of(rcdev, struct sp_reset, rcdev); 108 } 109 110 static int sp_reset_update(struct reset_controller_dev *rcdev, 111 unsigned long id, bool assert) 112 { 113 struct sp_reset *reset = to_sp_reset(rcdev); 114 int index = sp_resets[id] / BITS_PER_HWM_REG; 115 int shift = sp_resets[id] % BITS_PER_HWM_REG; 116 u32 val; 117 118 val = (1 << (16 + shift)) | (assert << shift); 119 writel(val, reset->base + (index * 4)); 120 121 return 0; 122 } 123 124 static int sp_reset_assert(struct reset_controller_dev *rcdev, 125 unsigned long id) 126 { 127 return sp_reset_update(rcdev, id, true); 128 } 129 130 static int sp_reset_deassert(struct reset_controller_dev *rcdev, 131 unsigned long id) 132 { 133 return sp_reset_update(rcdev, id, false); 134 } 135 136 static int sp_reset_status(struct reset_controller_dev *rcdev, 137 unsigned long id) 138 { 139 struct sp_reset *reset = to_sp_reset(rcdev); 140 int index = sp_resets[id] / BITS_PER_HWM_REG; 141 int shift = sp_resets[id] % BITS_PER_HWM_REG; 142 u32 reg; 143 144 reg = readl(reset->base + (index * 4)); 145 146 return !!(reg & BIT(shift)); 147 } 148 149 static const struct reset_control_ops sp_reset_ops = { 150 .assert = sp_reset_assert, 151 .deassert = sp_reset_deassert, 152 .status = sp_reset_status, 153 }; 154 155 static int sp_restart(struct sys_off_data *data) 156 { 157 struct sp_reset *reset = data->cb_data; 158 159 sp_reset_assert(&reset->rcdev, 0); 160 sp_reset_deassert(&reset->rcdev, 0); 161 162 return NOTIFY_DONE; 163 } 164 165 static int sp_reset_probe(struct platform_device *pdev) 166 { 167 struct device *dev = &pdev->dev; 168 struct sp_reset *reset; 169 struct resource *res; 170 int ret; 171 172 reset = devm_kzalloc(dev, sizeof(*reset), GFP_KERNEL); 173 if (!reset) 174 return -ENOMEM; 175 176 reset->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); 177 if (IS_ERR(reset->base)) 178 return PTR_ERR(reset->base); 179 180 reset->rcdev.ops = &sp_reset_ops; 181 reset->rcdev.owner = THIS_MODULE; 182 reset->rcdev.of_node = dev->of_node; 183 reset->rcdev.nr_resets = resource_size(res) / 4 * BITS_PER_HWM_REG; 184 185 ret = devm_reset_controller_register(dev, &reset->rcdev); 186 if (ret) 187 return ret; 188 189 return devm_register_sys_off_handler(&pdev->dev, SYS_OFF_MODE_RESTART, 190 192, sp_restart, reset); 191 } 192 193 static const struct of_device_id sp_reset_dt_ids[] = { 194 {.compatible = "sunplus,sp7021-reset",}, 195 { /* sentinel */ }, 196 }; 197 198 static struct platform_driver sp_reset_driver = { 199 .probe = sp_reset_probe, 200 .driver = { 201 .name = "sunplus-reset", 202 .of_match_table = sp_reset_dt_ids, 203 .suppress_bind_attrs = true, 204 }, 205 }; 206 builtin_platform_driver(sp_reset_driver); 207