1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
5 * Copyright (C) Sunplus Technology Co., Ltd.
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>
16 /* HIWORD_MASK_REG BITS */
17 #define BITS_PER_HWM_REG 16
19 /* resets HW info: reg_index_shift */
20 static const u32 sp_resets[] = {
21 /* SP7021: mo_reset0 ~ mo_reset9 */
102 struct reset_controller_dev rcdev;
103 struct notifier_block notifier;
107 static inline struct sp_reset *to_sp_reset(struct reset_controller_dev *rcdev)
109 return container_of(rcdev, struct sp_reset, rcdev);
112 static int sp_reset_update(struct reset_controller_dev *rcdev,
113 unsigned long id, bool assert)
115 struct sp_reset *reset = to_sp_reset(rcdev);
116 int index = sp_resets[id] / BITS_PER_HWM_REG;
117 int shift = sp_resets[id] % BITS_PER_HWM_REG;
120 val = (1 << (16 + shift)) | (assert << shift);
121 writel(val, reset->base + (index * 4));
126 static int sp_reset_assert(struct reset_controller_dev *rcdev,
129 return sp_reset_update(rcdev, id, true);
132 static int sp_reset_deassert(struct reset_controller_dev *rcdev,
135 return sp_reset_update(rcdev, id, false);
138 static int sp_reset_status(struct reset_controller_dev *rcdev,
141 struct sp_reset *reset = to_sp_reset(rcdev);
142 int index = sp_resets[id] / BITS_PER_HWM_REG;
143 int shift = sp_resets[id] % BITS_PER_HWM_REG;
146 reg = readl(reset->base + (index * 4));
148 return !!(reg & BIT(shift));
151 static const struct reset_control_ops sp_reset_ops = {
152 .assert = sp_reset_assert,
153 .deassert = sp_reset_deassert,
154 .status = sp_reset_status,
157 static int sp_restart(struct notifier_block *nb, unsigned long mode,
160 struct sp_reset *reset = container_of(nb, struct sp_reset, notifier);
162 sp_reset_assert(&reset->rcdev, 0);
163 sp_reset_deassert(&reset->rcdev, 0);
168 static int sp_reset_probe(struct platform_device *pdev)
170 struct device *dev = &pdev->dev;
171 struct sp_reset *reset;
172 struct resource *res;
175 reset = devm_kzalloc(dev, sizeof(*reset), GFP_KERNEL);
179 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
180 reset->base = devm_ioremap_resource(dev, res);
181 if (IS_ERR(reset->base))
182 return PTR_ERR(reset->base);
184 reset->rcdev.ops = &sp_reset_ops;
185 reset->rcdev.owner = THIS_MODULE;
186 reset->rcdev.of_node = dev->of_node;
187 reset->rcdev.nr_resets = resource_size(res) / 4 * BITS_PER_HWM_REG;
189 ret = devm_reset_controller_register(dev, &reset->rcdev);
193 reset->notifier.notifier_call = sp_restart;
194 reset->notifier.priority = 192;
196 return register_restart_handler(&reset->notifier);
199 static const struct of_device_id sp_reset_dt_ids[] = {
200 {.compatible = "sunplus,sp7021-reset",},
204 static struct platform_driver sp_reset_driver = {
205 .probe = sp_reset_probe,
207 .name = "sunplus-reset",
208 .of_match_table = sp_reset_dt_ids,
209 .suppress_bind_attrs = true,
212 builtin_platform_driver(sp_reset_driver);