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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * TI SYSCON regmap reset driver
4 *
5 * Copyright (C) 2015-2016 Texas Instruments Incorporated - https://www.ti.com/
6 * Andrew F. Davis <afd@ti.com>
7 * Suman Anna <afd@ti.com>
8 */
9
10#include <linux/mfd/syscon.h>
11#include <linux/module.h>
12#include <linux/of.h>
13#include <linux/platform_device.h>
14#include <linux/regmap.h>
15#include <linux/reset-controller.h>
16
17#include <dt-bindings/reset/ti-syscon.h>
18
19/**
20 * struct ti_syscon_reset_control - reset control structure
21 * @assert_offset: reset assert control register offset from syscon base
22 * @assert_bit: reset assert bit in the reset assert control register
23 * @deassert_offset: reset deassert control register offset from syscon base
24 * @deassert_bit: reset deassert bit in the reset deassert control register
25 * @status_offset: reset status register offset from syscon base
26 * @status_bit: reset status bit in the reset status register
27 * @flags: reset flag indicating how the (de)assert and status are handled
28 */
29struct ti_syscon_reset_control {
30 unsigned int assert_offset;
31 unsigned int assert_bit;
32 unsigned int deassert_offset;
33 unsigned int deassert_bit;
34 unsigned int status_offset;
35 unsigned int status_bit;
36 u32 flags;
37};
38
39/**
40 * struct ti_syscon_reset_data - reset controller information structure
41 * @rcdev: reset controller entity
42 * @regmap: regmap handle containing the memory-mapped reset registers
43 * @controls: array of reset controls
44 * @nr_controls: number of controls in control array
45 */
46struct ti_syscon_reset_data {
47 struct reset_controller_dev rcdev;
48 struct regmap *regmap;
49 struct ti_syscon_reset_control *controls;
50 unsigned int nr_controls;
51};
52
53#define to_ti_syscon_reset_data(_rcdev) \
54 container_of(_rcdev, struct ti_syscon_reset_data, rcdev)
55
56/**
57 * ti_syscon_reset_assert() - assert device reset
58 * @rcdev: reset controller entity
59 * @id: ID of the reset to be asserted
60 *
61 * This function implements the reset driver op to assert a device's reset.
62 * This asserts the reset in a manner prescribed by the reset flags.
63 *
64 * Return: 0 for successful request, else a corresponding error value
65 */
66static int ti_syscon_reset_assert(struct reset_controller_dev *rcdev,
67 unsigned long id)
68{
69 struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);
70 struct ti_syscon_reset_control *control;
71 unsigned int mask, value;
72
73 if (id >= data->nr_controls)
74 return -EINVAL;
75
76 control = &data->controls[id];
77
78 if (control->flags & ASSERT_NONE)
79 return -ENOTSUPP; /* assert not supported for this reset */
80
81 mask = BIT(control->assert_bit);
82 value = (control->flags & ASSERT_SET) ? mask : 0x0;
83
84 return regmap_write_bits(data->regmap, control->assert_offset, mask, value);
85}
86
87/**
88 * ti_syscon_reset_deassert() - deassert device reset
89 * @rcdev: reset controller entity
90 * @id: ID of reset to be deasserted
91 *
92 * This function implements the reset driver op to deassert a device's reset.
93 * This deasserts the reset in a manner prescribed by the reset flags.
94 *
95 * Return: 0 for successful request, else a corresponding error value
96 */
97static int ti_syscon_reset_deassert(struct reset_controller_dev *rcdev,
98 unsigned long id)
99{
100 struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);
101 struct ti_syscon_reset_control *control;
102 unsigned int mask, value;
103
104 if (id >= data->nr_controls)
105 return -EINVAL;
106
107 control = &data->controls[id];
108
109 if (control->flags & DEASSERT_NONE)
110 return -ENOTSUPP; /* deassert not supported for this reset */
111
112 mask = BIT(control->deassert_bit);
113 value = (control->flags & DEASSERT_SET) ? mask : 0x0;
114
115 return regmap_write_bits(data->regmap, control->deassert_offset, mask, value);
116}
117
118/**
119 * ti_syscon_reset_status() - check device reset status
120 * @rcdev: reset controller entity
121 * @id: ID of the reset for which the status is being requested
122 *
123 * This function implements the reset driver op to return the status of a
124 * device's reset.
125 *
126 * Return: 0 if reset is deasserted, true if reset is asserted, else a
127 * corresponding error value
128 */
129static int ti_syscon_reset_status(struct reset_controller_dev *rcdev,
130 unsigned long id)
131{
132 struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);
133 struct ti_syscon_reset_control *control;
134 unsigned int reset_state;
135 int ret;
136
137 if (id >= data->nr_controls)
138 return -EINVAL;
139
140 control = &data->controls[id];
141
142 if (control->flags & STATUS_NONE)
143 return -ENOTSUPP; /* status not supported for this reset */
144
145 ret = regmap_read(data->regmap, control->status_offset, &reset_state);
146 if (ret)
147 return ret;
148
149 return !(reset_state & BIT(control->status_bit)) ==
150 !(control->flags & STATUS_SET);
151}
152
153static const struct reset_control_ops ti_syscon_reset_ops = {
154 .assert = ti_syscon_reset_assert,
155 .deassert = ti_syscon_reset_deassert,
156 .status = ti_syscon_reset_status,
157};
158
159static int ti_syscon_reset_probe(struct platform_device *pdev)
160{
161 struct device *dev = &pdev->dev;
162 struct device_node *np = dev->of_node;
163 struct ti_syscon_reset_data *data;
164 struct regmap *regmap;
165 const __be32 *list;
166 struct ti_syscon_reset_control *controls;
167 int size, nr_controls, i;
168
169 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
170 if (!data)
171 return -ENOMEM;
172
173 regmap = syscon_node_to_regmap(np->parent);
174 if (IS_ERR(regmap))
175 return PTR_ERR(regmap);
176
177 list = of_get_property(np, "ti,reset-bits", &size);
178 if (!list || (size / sizeof(*list)) % 7 != 0) {
179 dev_err(dev, "invalid DT reset description\n");
180 return -EINVAL;
181 }
182
183 nr_controls = (size / sizeof(*list)) / 7;
184 controls = devm_kcalloc(dev, nr_controls, sizeof(*controls),
185 GFP_KERNEL);
186 if (!controls)
187 return -ENOMEM;
188
189 for (i = 0; i < nr_controls; i++) {
190 controls[i].assert_offset = be32_to_cpup(list++);
191 controls[i].assert_bit = be32_to_cpup(list++);
192 controls[i].deassert_offset = be32_to_cpup(list++);
193 controls[i].deassert_bit = be32_to_cpup(list++);
194 controls[i].status_offset = be32_to_cpup(list++);
195 controls[i].status_bit = be32_to_cpup(list++);
196 controls[i].flags = be32_to_cpup(list++);
197 }
198
199 data->rcdev.ops = &ti_syscon_reset_ops;
200 data->rcdev.owner = THIS_MODULE;
201 data->rcdev.of_node = np;
202 data->rcdev.nr_resets = nr_controls;
203 data->regmap = regmap;
204 data->controls = controls;
205 data->nr_controls = nr_controls;
206
207 return devm_reset_controller_register(dev, &data->rcdev);
208}
209
210static const struct of_device_id ti_syscon_reset_of_match[] = {
211 { .compatible = "ti,syscon-reset", },
212 { /* sentinel */ },
213};
214MODULE_DEVICE_TABLE(of, ti_syscon_reset_of_match);
215
216static struct platform_driver ti_syscon_reset_driver = {
217 .probe = ti_syscon_reset_probe,
218 .driver = {
219 .name = "ti-syscon-reset",
220 .of_match_table = ti_syscon_reset_of_match,
221 },
222};
223module_platform_driver(ti_syscon_reset_driver);
224
225MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
226MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
227MODULE_DESCRIPTION("TI SYSCON Regmap Reset Driver");
228MODULE_LICENSE("GPL v2");
1/*
2 * TI SYSCON regmap reset driver
3 *
4 * Copyright (C) 2015-2016 Texas Instruments Incorporated - https://www.ti.com/
5 * Andrew F. Davis <afd@ti.com>
6 * Suman Anna <afd@ti.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
13 * kind, whether express or implied; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 */
17
18#include <linux/mfd/syscon.h>
19#include <linux/module.h>
20#include <linux/of.h>
21#include <linux/platform_device.h>
22#include <linux/regmap.h>
23#include <linux/reset-controller.h>
24
25#include <dt-bindings/reset/ti-syscon.h>
26
27/**
28 * struct ti_syscon_reset_control - reset control structure
29 * @assert_offset: reset assert control register offset from syscon base
30 * @assert_bit: reset assert bit in the reset assert control register
31 * @deassert_offset: reset deassert control register offset from syscon base
32 * @deassert_bit: reset deassert bit in the reset deassert control register
33 * @status_offset: reset status register offset from syscon base
34 * @status_bit: reset status bit in the reset status register
35 * @flags: reset flag indicating how the (de)assert and status are handled
36 */
37struct ti_syscon_reset_control {
38 unsigned int assert_offset;
39 unsigned int assert_bit;
40 unsigned int deassert_offset;
41 unsigned int deassert_bit;
42 unsigned int status_offset;
43 unsigned int status_bit;
44 u32 flags;
45};
46
47/**
48 * struct ti_syscon_reset_data - reset controller information structure
49 * @rcdev: reset controller entity
50 * @regmap: regmap handle containing the memory-mapped reset registers
51 * @controls: array of reset controls
52 * @nr_controls: number of controls in control array
53 */
54struct ti_syscon_reset_data {
55 struct reset_controller_dev rcdev;
56 struct regmap *regmap;
57 struct ti_syscon_reset_control *controls;
58 unsigned int nr_controls;
59};
60
61#define to_ti_syscon_reset_data(rcdev) \
62 container_of(rcdev, struct ti_syscon_reset_data, rcdev)
63
64/**
65 * ti_syscon_reset_assert() - assert device reset
66 * @rcdev: reset controller entity
67 * @id: ID of the reset to be asserted
68 *
69 * This function implements the reset driver op to assert a device's reset.
70 * This asserts the reset in a manner prescribed by the reset flags.
71 *
72 * Return: 0 for successful request, else a corresponding error value
73 */
74static int ti_syscon_reset_assert(struct reset_controller_dev *rcdev,
75 unsigned long id)
76{
77 struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);
78 struct ti_syscon_reset_control *control;
79 unsigned int mask, value;
80
81 if (id >= data->nr_controls)
82 return -EINVAL;
83
84 control = &data->controls[id];
85
86 if (control->flags & ASSERT_NONE)
87 return -ENOTSUPP; /* assert not supported for this reset */
88
89 mask = BIT(control->assert_bit);
90 value = (control->flags & ASSERT_SET) ? mask : 0x0;
91
92 return regmap_update_bits(data->regmap, control->assert_offset, mask, value);
93}
94
95/**
96 * ti_syscon_reset_deassert() - deassert device reset
97 * @rcdev: reset controller entity
98 * @id: ID of reset to be deasserted
99 *
100 * This function implements the reset driver op to deassert a device's reset.
101 * This deasserts the reset in a manner prescribed by the reset flags.
102 *
103 * Return: 0 for successful request, else a corresponding error value
104 */
105static int ti_syscon_reset_deassert(struct reset_controller_dev *rcdev,
106 unsigned long id)
107{
108 struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);
109 struct ti_syscon_reset_control *control;
110 unsigned int mask, value;
111
112 if (id >= data->nr_controls)
113 return -EINVAL;
114
115 control = &data->controls[id];
116
117 if (control->flags & DEASSERT_NONE)
118 return -ENOTSUPP; /* deassert not supported for this reset */
119
120 mask = BIT(control->deassert_bit);
121 value = (control->flags & DEASSERT_SET) ? mask : 0x0;
122
123 return regmap_update_bits(data->regmap, control->deassert_offset, mask, value);
124}
125
126/**
127 * ti_syscon_reset_status() - check device reset status
128 * @rcdev: reset controller entity
129 * @id: ID of the reset for which the status is being requested
130 *
131 * This function implements the reset driver op to return the status of a
132 * device's reset.
133 *
134 * Return: 0 if reset is deasserted, true if reset is asserted, else a
135 * corresponding error value
136 */
137static int ti_syscon_reset_status(struct reset_controller_dev *rcdev,
138 unsigned long id)
139{
140 struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);
141 struct ti_syscon_reset_control *control;
142 unsigned int reset_state;
143 int ret;
144
145 if (id >= data->nr_controls)
146 return -EINVAL;
147
148 control = &data->controls[id];
149
150 if (control->flags & STATUS_NONE)
151 return -ENOTSUPP; /* status not supported for this reset */
152
153 ret = regmap_read(data->regmap, control->status_offset, &reset_state);
154 if (ret)
155 return ret;
156
157 return !(reset_state & BIT(control->status_bit)) ==
158 !(control->flags & STATUS_SET);
159}
160
161static const struct reset_control_ops ti_syscon_reset_ops = {
162 .assert = ti_syscon_reset_assert,
163 .deassert = ti_syscon_reset_deassert,
164 .status = ti_syscon_reset_status,
165};
166
167static int ti_syscon_reset_probe(struct platform_device *pdev)
168{
169 struct device *dev = &pdev->dev;
170 struct device_node *np = dev->of_node;
171 struct ti_syscon_reset_data *data;
172 struct regmap *regmap;
173 const __be32 *list;
174 struct ti_syscon_reset_control *controls;
175 int size, nr_controls, i;
176
177 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
178 if (!data)
179 return -ENOMEM;
180
181 regmap = syscon_node_to_regmap(np->parent);
182 if (IS_ERR(regmap))
183 return PTR_ERR(regmap);
184
185 list = of_get_property(np, "ti,reset-bits", &size);
186 if (!list || (size / sizeof(*list)) % 7 != 0) {
187 dev_err(dev, "invalid DT reset description\n");
188 return -EINVAL;
189 }
190
191 nr_controls = (size / sizeof(*list)) / 7;
192 controls = devm_kcalloc(dev, nr_controls, sizeof(*controls),
193 GFP_KERNEL);
194 if (!controls)
195 return -ENOMEM;
196
197 for (i = 0; i < nr_controls; i++) {
198 controls[i].assert_offset = be32_to_cpup(list++);
199 controls[i].assert_bit = be32_to_cpup(list++);
200 controls[i].deassert_offset = be32_to_cpup(list++);
201 controls[i].deassert_bit = be32_to_cpup(list++);
202 controls[i].status_offset = be32_to_cpup(list++);
203 controls[i].status_bit = be32_to_cpup(list++);
204 controls[i].flags = be32_to_cpup(list++);
205 }
206
207 data->rcdev.ops = &ti_syscon_reset_ops;
208 data->rcdev.owner = THIS_MODULE;
209 data->rcdev.of_node = np;
210 data->rcdev.nr_resets = nr_controls;
211 data->regmap = regmap;
212 data->controls = controls;
213 data->nr_controls = nr_controls;
214
215 platform_set_drvdata(pdev, data);
216
217 return devm_reset_controller_register(dev, &data->rcdev);
218}
219
220static const struct of_device_id ti_syscon_reset_of_match[] = {
221 { .compatible = "ti,syscon-reset", },
222 { /* sentinel */ },
223};
224MODULE_DEVICE_TABLE(of, ti_syscon_reset_of_match);
225
226static struct platform_driver ti_syscon_reset_driver = {
227 .probe = ti_syscon_reset_probe,
228 .driver = {
229 .name = "ti-syscon-reset",
230 .of_match_table = ti_syscon_reset_of_match,
231 },
232};
233module_platform_driver(ti_syscon_reset_driver);
234
235MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
236MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
237MODULE_DESCRIPTION("TI SYSCON Regmap Reset Driver");
238MODULE_LICENSE("GPL v2");