summaryrefslogtreecommitdiffstats
path: root/drivers/reset/reset-a10sr.c
blob: 306fba5b3519372ab7db064c91842e70dce3be70 (plain)
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
/*
 *  Copyright Intel Corporation (C) 2017. All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Reset driver for Altera Arria10 MAX5 System Resource Chip
 *
 * Adapted from reset-socfpga.c
 */

#include <linux/err.h>
#include <linux/mfd/altera-a10sr.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reset-controller.h>

#include <dt-bindings/reset/altr,rst-mgr-a10sr.h>

struct a10sr_reset {
	struct reset_controller_dev     rcdev;
	struct regmap *regmap;
};

static inline struct a10sr_reset *to_a10sr_rst(struct reset_controller_dev *rc)
{
	return container_of(rc, struct a10sr_reset, rcdev);
}

static inline int a10sr_reset_shift(unsigned long id)
{
	switch (id) {
	case A10SR_RESET_ENET_HPS:
		return 1;
	case A10SR_RESET_PCIE:
	case A10SR_RESET_FILE:
	case A10SR_RESET_BQSPI:
	case A10SR_RESET_USB:
		return id + 11;
	default:
		return -EINVAL;
	}
}

static int a10sr_reset_update(struct reset_controller_dev *rcdev,
			      unsigned long id, bool assert)
{
	struct a10sr_reset *a10r = to_a10sr_rst(rcdev);
	int offset = a10sr_reset_shift(id);
	u8 mask = ALTR_A10SR_REG_BIT_MASK(offset);
	int index = ALTR_A10SR_HPS_RST_REG + ALTR_A10SR_REG_OFFSET(offset);

	return regmap_update_bits(a10r->regmap, index, mask, assert ? 0 : mask);
}

static int a10sr_reset_assert(struct reset_controller_dev *rcdev,
			      unsigned long id)
{
	return a10sr_reset_update(rcdev, id, true);
}

static int a10sr_reset_deassert(struct reset_controller_dev *rcdev,
				unsigned long id)
{
	return a10sr_reset_update(rcdev, id, false);
}

static int a10sr_reset_status(struct reset_controller_dev *rcdev,
			      unsigned long id)
{
	int ret;
	struct a10sr_reset *a10r = to_a10sr_rst(rcdev);
	int offset = a10sr_reset_shift(id);
	u8 mask = ALTR_A10SR_REG_BIT_MASK(offset);
	int index = ALTR_A10SR_HPS_RST_REG + ALTR_A10SR_REG_OFFSET(offset);
	unsigned int value;

	ret = regmap_read(a10r->regmap, index, &value);
	if (ret < 0)
		return ret;

	return !!(value & mask);
}

static const struct reset_control_ops a10sr_reset_ops = {
	.assert		= a10sr_reset_assert,
	.deassert	= a10sr_reset_deassert,
	.status		= a10sr_reset_status,
};

static int a10sr_reset_probe(struct platform_device *pdev)
{
	struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent);
	struct a10sr_reset *a10r;

	a10r = devm_kzalloc(&pdev->dev, sizeof(struct a10sr_reset),
			    GFP_KERNEL);
	if (!a10r)
		return -ENOMEM;

	a10r->rcdev.owner = THIS_MODULE;
	a10r->rcdev.nr_resets = A10SR_RESET_NUM;
	a10r->rcdev.ops = &a10sr_reset_ops;
	a10r->rcdev.of_node = pdev->dev.of_node;
	a10r->regmap = a10sr->regmap;

	platform_set_drvdata(pdev, a10r);

	return devm_reset_controller_register(&pdev->dev, &a10r->rcdev);
}

static const struct of_device_id a10sr_reset_of_match[] = {
	{ .compatible = "altr,a10sr-reset" },
	{ },
};
MODULE_DEVICE_TABLE(of, a10sr_reset_of_match);

static struct platform_driver a10sr_reset_driver = {
	.probe	= a10sr_reset_probe,
	.driver = {
		.name		= "altr_a10sr_reset",
		.of_match_table	= a10sr_reset_of_match,
	},
};
module_platform_driver(a10sr_reset_driver);

MODULE_AUTHOR("Thor Thayer <thor.thayer@linux.intel.com>");
MODULE_DESCRIPTION("Altera Arria10 System Resource Reset Controller Driver");
MODULE_LICENSE("GPL v2");