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/mod_devicetable.h> 12 #include <linux/platform_device.h> 13 #include <linux/reset-controller.h> 14 #include <linux/reboot.h> 15 16 /* HIWORD_MASK_REG BITS */ 17 #define BITS_PER_HWM_REG 16 18 19 /* resets HW info: reg_index_shift */ 20 static const u32 sp_resets[] = { 21 /* SP7021: mo_reset0 ~ mo_reset9 */ 22 0x00, 23 0x02, 24 0x03, 25 0x04, 26 0x05, 27 0x06, 28 0x07, 29 0x08, 30 0x09, 31 0x0a, 32 0x0b, 33 0x0d, 34 0x0e, 35 0x0f, 36 0x10, 37 0x12, 38 0x14, 39 0x15, 40 0x16, 41 0x17, 42 0x18, 43 0x19, 44 0x1a, 45 0x1b, 46 0x1c, 47 0x1d, 48 0x1e, 49 0x1f, 50 0x20, 51 0x21, 52 0x22, 53 0x23, 54 0x24, 55 0x25, 56 0x26, 57 0x2a, 58 0x2b, 59 0x2d, 60 0x2e, 61 0x30, 62 0x31, 63 0x32, 64 0x33, 65 0x3d, 66 0x3e, 67 0x3f, 68 0x42, 69 0x44, 70 0x4b, 71 0x4c, 72 0x4d, 73 0x4e, 74 0x4f, 75 0x50, 76 0x55, 77 0x60, 78 0x61, 79 0x6a, 80 0x6f, 81 0x70, 82 0x73, 83 0x74, 84 0x86, 85 0x8a, 86 0x8b, 87 0x8d, 88 0x8e, 89 0x8f, 90 0x90, 91 0x92, 92 0x93, 93 0x94, 94 0x95, 95 0x96, 96 0x97, 97 0x98, 98 0x99, 99 }; 100 101 struct sp_reset { 102 struct reset_controller_dev rcdev; 103 void __iomem *base; 104 }; 105 106 static inline struct sp_reset *to_sp_reset(struct reset_controller_dev *rcdev) 107 { 108 return container_of(rcdev, struct sp_reset, rcdev); 109 } 110 111 static int sp_reset_update(struct reset_controller_dev *rcdev, 112 unsigned long id, bool assert) 113 { 114 struct sp_reset *reset = to_sp_reset(rcdev); 115 int index = sp_resets[id] / BITS_PER_HWM_REG; 116 int shift = sp_resets[id] % BITS_PER_HWM_REG; 117 u32 val; 118 119 val = (1 << (16 + shift)) | (assert << shift); 120 writel(val, reset->base + (index * 4)); 121 122 return 0; 123 } 124 125 static int sp_reset_assert(struct reset_controller_dev *rcdev, 126 unsigned long id) 127 { 128 return sp_reset_update(rcdev, id, true); 129 } 130 131 static int sp_reset_deassert(struct reset_controller_dev *rcdev, 132 unsigned long id) 133 { 134 return sp_reset_update(rcdev, id, false); 135 } 136 137 static int sp_reset_status(struct reset_controller_dev *rcdev, 138 unsigned long id) 139 { 140 struct sp_reset *reset = to_sp_reset(rcdev); 141 int index = sp_resets[id] / BITS_PER_HWM_REG; 142 int shift = sp_resets[id] % BITS_PER_HWM_REG; 143 u32 reg; 144 145 reg = readl(reset->base + (index * 4)); 146 147 return !!(reg & BIT(shift)); 148 } 149 150 static const struct reset_control_ops sp_reset_ops = { 151 .assert = sp_reset_assert, 152 .deassert = sp_reset_deassert, 153 .status = sp_reset_status, 154 }; 155 156 static int sp_restart(struct sys_off_data *data) 157 { 158 struct sp_reset *reset = data->cb_data; 159 160 sp_reset_assert(&reset->rcdev, 0); 161 sp_reset_deassert(&reset->rcdev, 0); 162 163 return NOTIFY_DONE; 164 } 165 166 static int sp_reset_probe(struct platform_device *pdev) 167 { 168 struct device *dev = &pdev->dev; 169 struct sp_reset *reset; 170 struct resource *res; 171 int ret; 172 173 reset = devm_kzalloc(dev, sizeof(*reset), GFP_KERNEL); 174 if (!reset) 175 return -ENOMEM; 176 177 reset->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); 178 if (IS_ERR(reset->base)) 179 return PTR_ERR(reset->base); 180 181 reset->rcdev.ops = &sp_reset_ops; 182 reset->rcdev.owner = THIS_MODULE; 183 reset->rcdev.of_node = dev->of_node; 184 reset->rcdev.nr_resets = resource_size(res) / 4 * BITS_PER_HWM_REG; 185 186 ret = devm_reset_controller_register(dev, &reset->rcdev); 187 if (ret) 188 return ret; 189 190 return devm_register_sys_off_handler(&pdev->dev, SYS_OFF_MODE_RESTART, 191 192, sp_restart, reset); 192 } 193 194 static const struct of_device_id sp_reset_dt_ids[] = { 195 {.compatible = "sunplus,sp7021-reset",}, 196 { /* sentinel */ }, 197 }; 198 199 static struct platform_driver sp_reset_driver = { 200 .probe = sp_reset_probe, 201 .driver = { 202 .name = "sunplus-reset", 203 .of_match_table = sp_reset_dt_ids, 204 .suppress_bind_attrs = true, 205 }, 206 }; 207 builtin_platform_driver(sp_reset_driver); 208