1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* TI SYSCON regmap reset driver
*
* Copyright (C) 2015-2016 Texas Instruments Incorporated - https://www.ti.com/
* Andrew F. Davis <afd@ti.com>
* Suman Anna <afd@ti.com>
*/
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reset-controller.h>
#include <dt-bindings/reset/ti-syscon.h>
/**
* struct ti_syscon_reset_control - reset control structure
* @assert_offset: reset assert control register offset from syscon base
* @assert_bit: reset assert bit in the reset assert control register
* @deassert_offset: reset deassert control register offset from syscon base
* @deassert_bit: reset deassert bit in the reset deassert control register
* @status_offset: reset status register offset from syscon base
* @status_bit: reset status bit in the reset status register
* @flags: reset flag indicating how the (de)assert and status are handled
*/
struct ti_syscon_reset_control {
unsigned int assert_offset;
unsigned int assert_bit;
unsigned int deassert_offset;
unsigned int deassert_bit;
unsigned int status_offset;
unsigned int status_bit;
u32 flags;
};
/**
* struct ti_syscon_reset_data - reset controller information structure
* @rcdev: reset controller entity
* @regmap: regmap handle containing the memory-mapped reset registers
* @controls: array of reset controls
* @nr_controls: number of controls in control array
*/
struct ti_syscon_reset_data {
struct reset_controller_dev rcdev;
struct regmap *regmap;
struct ti_syscon_reset_control *controls;
unsigned int nr_controls;
};
#define to_ti_syscon_reset_data(_rcdev) \
container_of(_rcdev, struct ti_syscon_reset_data, rcdev)
/**
* ti_syscon_reset_assert() - assert device reset
* @rcdev: reset controller entity
* @id: ID of the reset to be asserted
*
* This function implements the reset driver op to assert a device's reset.
* This asserts the reset in a manner prescribed by the reset flags.
*
* Return: 0 for successful request, else a corresponding error value
*/
static int ti_syscon_reset_assert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);
struct ti_syscon_reset_control *control;
unsigned int mask, value;
if (id >= data->nr_controls)
return -EINVAL;
control = &data->controls[id];
if (control->flags & ASSERT_NONE)
return -ENOTSUPP; /* assert not supported for this reset */
mask = BIT(control->assert_bit);
value = (control->flags & ASSERT_SET) ? mask : 0x0;
return regmap_write_bits(data->regmap, control->assert_offset, mask, value);
}
/**
* ti_syscon_reset_deassert() - deassert device reset
* @rcdev: reset controller entity
* @id: ID of reset to be deasserted
*
* This function implements the reset driver op to deassert a device's reset.
* This deasserts the reset in a manner prescribed by the reset flags.
*
* Return: 0 for successful request, else a corresponding error value
*/
static int ti_syscon_reset_deassert(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);
struct ti_syscon_reset_control *control;
unsigned int mask, value;
if (id >= data->nr_controls)
return -EINVAL;
control = &data->controls[id];
if (control->flags & DEASSERT_NONE)
return -ENOTSUPP; /* deassert not supported for this reset */
mask = BIT(control->deassert_bit);
value = (control->flags & DEASSERT_SET) ? mask : 0x0;
return regmap_write_bits(data->regmap, control->deassert_offset, mask, value);
}
/**
* ti_syscon_reset_status() - check device reset status
* @rcdev: reset controller entity
* @id: ID of the reset for which the status is being requested
*
* This function implements the reset driver op to return the status of a
* device's reset.
*
* Return: 0 if reset is deasserted, true if reset is asserted, else a
* corresponding error value
*/
static int ti_syscon_reset_status(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);
struct ti_syscon_reset_control *control;
unsigned int reset_state;
int ret;
if (id >= data->nr_controls)
return -EINVAL;
control = &data->controls[id];
if (control->flags & STATUS_NONE)
return -ENOTSUPP; /* status not supported for this reset */
ret = regmap_read(data->regmap, control->status_offset, &reset_state);
if (ret)
return ret;
return !(reset_state & BIT(control->status_bit)) ==
!(control->flags & STATUS_SET);
}
static const struct reset_control_ops ti_syscon_reset_ops = {
.assert = ti_syscon_reset_assert,
.deassert = ti_syscon_reset_deassert,
.status = ti_syscon_reset_status,
};
static int ti_syscon_reset_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct ti_syscon_reset_data *data;
struct regmap *regmap;
const __be32 *list;
struct ti_syscon_reset_control *controls;
int size, nr_controls, i;
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
regmap = syscon_node_to_regmap(np->parent);
if (IS_ERR(regmap))
return PTR_ERR(regmap);
list = of_get_property(np, "ti,reset-bits", &size);
if (!list || (size / sizeof(*list)) % 7 != 0) {
dev_err(dev, "invalid DT reset description\n");
return -EINVAL;
}
nr_controls = (size / sizeof(*list)) / 7;
controls = devm_kcalloc(dev, nr_controls, sizeof(*controls),
GFP_KERNEL);
if (!controls)
return -ENOMEM;
for (i = 0; i < nr_controls; i++) {
controls[i].assert_offset = be32_to_cpup(list++);
controls[i].assert_bit = be32_to_cpup(list++);
controls[i].deassert_offset = be32_to_cpup(list++);
controls[i].deassert_bit = be32_to_cpup(list++);
controls[i].status_offset = be32_to_cpup(list++);
controls[i].status_bit = be32_to_cpup(list++);
controls[i].flags = be32_to_cpup(list++);
}
data->rcdev.ops = &ti_syscon_reset_ops;
data->rcdev.owner = THIS_MODULE;
data->rcdev.of_node = np;
data->rcdev.nr_resets = nr_controls;
data->regmap = regmap;
data->controls = controls;
data->nr_controls = nr_controls;
return devm_reset_controller_register(dev, &data->rcdev);
}
static const struct of_device_id ti_syscon_reset_of_match[] = {
{ .compatible = "ti,syscon-reset", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, ti_syscon_reset_of_match);
static struct platform_driver ti_syscon_reset_driver = {
.probe = ti_syscon_reset_probe,
.driver = {
.name = "ti-syscon-reset",
.of_match_table = ti_syscon_reset_of_match,
},
};
module_platform_driver(ti_syscon_reset_driver);
MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
MODULE_DESCRIPTION("TI SYSCON Regmap Reset Driver");
MODULE_LICENSE("GPL v2");
|
