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62700682 TT |
1 | /* |
2 | * Copyright Intel Corporation (C) 2017. All Rights Reserved | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms and conditions of the GNU General Public License, | |
6 | * version 2, as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
11 | * more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License along with | |
14 | * this program. If not, see <http://www.gnu.org/licenses/>. | |
15 | * | |
16 | * Reset driver for Altera Arria10 MAX5 System Resource Chip | |
17 | * | |
18 | * Adapted from reset-socfpga.c | |
19 | */ | |
20 | ||
21 | #include <linux/err.h> | |
22 | #include <linux/mfd/altera-a10sr.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/of.h> | |
25 | #include <linux/platform_device.h> | |
26 | #include <linux/reset-controller.h> | |
27 | ||
28 | #include <dt-bindings/reset/altr,rst-mgr-a10sr.h> | |
29 | ||
30 | struct a10sr_reset { | |
31 | struct reset_controller_dev rcdev; | |
32 | struct regmap *regmap; | |
33 | }; | |
34 | ||
35 | static inline struct a10sr_reset *to_a10sr_rst(struct reset_controller_dev *rc) | |
36 | { | |
37 | return container_of(rc, struct a10sr_reset, rcdev); | |
38 | } | |
39 | ||
40 | static inline int a10sr_reset_shift(unsigned long id) | |
41 | { | |
42 | switch (id) { | |
43 | case A10SR_RESET_ENET_HPS: | |
44 | return 1; | |
45 | case A10SR_RESET_PCIE: | |
46 | case A10SR_RESET_FILE: | |
47 | case A10SR_RESET_BQSPI: | |
48 | case A10SR_RESET_USB: | |
49 | return id + 11; | |
50 | default: | |
51 | return -EINVAL; | |
52 | } | |
53 | } | |
54 | ||
55 | static int a10sr_reset_update(struct reset_controller_dev *rcdev, | |
56 | unsigned long id, bool assert) | |
57 | { | |
58 | struct a10sr_reset *a10r = to_a10sr_rst(rcdev); | |
59 | int offset = a10sr_reset_shift(id); | |
60 | u8 mask = ALTR_A10SR_REG_BIT_MASK(offset); | |
61 | int index = ALTR_A10SR_HPS_RST_REG + ALTR_A10SR_REG_OFFSET(offset); | |
62 | ||
63 | return regmap_update_bits(a10r->regmap, index, mask, assert ? 0 : mask); | |
64 | } | |
65 | ||
66 | static int a10sr_reset_assert(struct reset_controller_dev *rcdev, | |
67 | unsigned long id) | |
68 | { | |
69 | return a10sr_reset_update(rcdev, id, true); | |
70 | } | |
71 | ||
72 | static int a10sr_reset_deassert(struct reset_controller_dev *rcdev, | |
73 | unsigned long id) | |
74 | { | |
75 | return a10sr_reset_update(rcdev, id, false); | |
76 | } | |
77 | ||
78 | static int a10sr_reset_status(struct reset_controller_dev *rcdev, | |
79 | unsigned long id) | |
80 | { | |
81 | int ret; | |
82 | struct a10sr_reset *a10r = to_a10sr_rst(rcdev); | |
83 | int offset = a10sr_reset_shift(id); | |
84 | u8 mask = ALTR_A10SR_REG_BIT_MASK(offset); | |
85 | int index = ALTR_A10SR_HPS_RST_REG + ALTR_A10SR_REG_OFFSET(offset); | |
86 | unsigned int value; | |
87 | ||
88 | ret = regmap_read(a10r->regmap, index, &value); | |
89 | if (ret < 0) | |
90 | return ret; | |
91 | ||
92 | return !!(value & mask); | |
93 | } | |
94 | ||
95 | static const struct reset_control_ops a10sr_reset_ops = { | |
96 | .assert = a10sr_reset_assert, | |
97 | .deassert = a10sr_reset_deassert, | |
98 | .status = a10sr_reset_status, | |
99 | }; | |
100 | ||
101 | static int a10sr_reset_probe(struct platform_device *pdev) | |
102 | { | |
103 | struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent); | |
104 | struct a10sr_reset *a10r; | |
105 | ||
106 | a10r = devm_kzalloc(&pdev->dev, sizeof(struct a10sr_reset), | |
107 | GFP_KERNEL); | |
108 | if (!a10r) | |
109 | return -ENOMEM; | |
110 | ||
111 | a10r->rcdev.owner = THIS_MODULE; | |
112 | a10r->rcdev.nr_resets = A10SR_RESET_NUM; | |
113 | a10r->rcdev.ops = &a10sr_reset_ops; | |
114 | a10r->rcdev.of_node = pdev->dev.of_node; | |
115 | a10r->regmap = a10sr->regmap; | |
116 | ||
117 | platform_set_drvdata(pdev, a10r); | |
118 | ||
119 | return devm_reset_controller_register(&pdev->dev, &a10r->rcdev); | |
120 | } | |
121 | ||
122 | static const struct of_device_id a10sr_reset_of_match[] = { | |
123 | { .compatible = "altr,a10sr-reset" }, | |
124 | { }, | |
125 | }; | |
126 | MODULE_DEVICE_TABLE(of, a10sr_reset_of_match); | |
127 | ||
128 | static struct platform_driver a10sr_reset_driver = { | |
129 | .probe = a10sr_reset_probe, | |
130 | .driver = { | |
131 | .name = "altr_a10sr_reset", | |
132 | }, | |
133 | }; | |
134 | module_platform_driver(a10sr_reset_driver); | |
135 | ||
136 | MODULE_AUTHOR("Thor Thayer <thor.thayer@linux.intel.com>"); | |
137 | MODULE_DESCRIPTION("Altera Arria10 System Resource Reset Controller Driver"); | |
138 | MODULE_LICENSE("GPL v2"); |