1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright Intel Corporation (C) 2017. All Rights Reserved |
4 | * |
5 | * Reset driver for Altera Arria10 MAX5 System Resource Chip |
6 | * |
7 | * Adapted from reset-socfpga.c |
8 | */ |
9 | |
10 | #include <linux/err.h> |
11 | #include <linux/mfd/altera-a10sr.h> |
12 | #include <linux/module.h> |
13 | #include <linux/of.h> |
14 | #include <linux/platform_device.h> |
15 | #include <linux/reset-controller.h> |
16 | |
17 | #include <dt-bindings/reset/altr,rst-mgr-a10sr.h> |
18 | |
19 | struct a10sr_reset { |
20 | struct reset_controller_dev rcdev; |
21 | struct regmap *regmap; |
22 | }; |
23 | |
24 | static inline struct a10sr_reset *to_a10sr_rst(struct reset_controller_dev *rc) |
25 | { |
26 | return container_of(rc, struct a10sr_reset, rcdev); |
27 | } |
28 | |
29 | static inline int a10sr_reset_shift(unsigned long id) |
30 | { |
31 | switch (id) { |
32 | case A10SR_RESET_ENET_HPS: |
33 | return 1; |
34 | case A10SR_RESET_PCIE: |
35 | case A10SR_RESET_FILE: |
36 | case A10SR_RESET_BQSPI: |
37 | case A10SR_RESET_USB: |
38 | return id + 11; |
39 | default: |
40 | return -EINVAL; |
41 | } |
42 | } |
43 | |
44 | static int a10sr_reset_update(struct reset_controller_dev *rcdev, |
45 | unsigned long id, bool assert) |
46 | { |
47 | struct a10sr_reset *a10r = to_a10sr_rst(rc: rcdev); |
48 | int offset = a10sr_reset_shift(id); |
49 | u8 mask = ALTR_A10SR_REG_BIT_MASK(offset); |
50 | int index = ALTR_A10SR_HPS_RST_REG + ALTR_A10SR_REG_OFFSET(offset); |
51 | |
52 | return regmap_update_bits(map: a10r->regmap, reg: index, mask, val: assert ? 0 : mask); |
53 | } |
54 | |
55 | static int a10sr_reset_assert(struct reset_controller_dev *rcdev, |
56 | unsigned long id) |
57 | { |
58 | return a10sr_reset_update(rcdev, id, assert: true); |
59 | } |
60 | |
61 | static int a10sr_reset_deassert(struct reset_controller_dev *rcdev, |
62 | unsigned long id) |
63 | { |
64 | return a10sr_reset_update(rcdev, id, assert: false); |
65 | } |
66 | |
67 | static int a10sr_reset_status(struct reset_controller_dev *rcdev, |
68 | unsigned long id) |
69 | { |
70 | int ret; |
71 | struct a10sr_reset *a10r = to_a10sr_rst(rc: rcdev); |
72 | int offset = a10sr_reset_shift(id); |
73 | u8 mask = ALTR_A10SR_REG_BIT_MASK(offset); |
74 | int index = ALTR_A10SR_HPS_RST_REG + ALTR_A10SR_REG_OFFSET(offset); |
75 | unsigned int value; |
76 | |
77 | ret = regmap_read(map: a10r->regmap, reg: index, val: &value); |
78 | if (ret < 0) |
79 | return ret; |
80 | |
81 | return !!(value & mask); |
82 | } |
83 | |
84 | static const struct reset_control_ops a10sr_reset_ops = { |
85 | .assert = a10sr_reset_assert, |
86 | .deassert = a10sr_reset_deassert, |
87 | .status = a10sr_reset_status, |
88 | }; |
89 | |
90 | static int a10sr_reset_probe(struct platform_device *pdev) |
91 | { |
92 | struct altr_a10sr *a10sr = dev_get_drvdata(dev: pdev->dev.parent); |
93 | struct a10sr_reset *a10r; |
94 | |
95 | a10r = devm_kzalloc(dev: &pdev->dev, size: sizeof(struct a10sr_reset), |
96 | GFP_KERNEL); |
97 | if (!a10r) |
98 | return -ENOMEM; |
99 | |
100 | a10r->rcdev.owner = THIS_MODULE; |
101 | a10r->rcdev.nr_resets = A10SR_RESET_NUM; |
102 | a10r->rcdev.ops = &a10sr_reset_ops; |
103 | a10r->rcdev.of_node = pdev->dev.of_node; |
104 | a10r->regmap = a10sr->regmap; |
105 | |
106 | platform_set_drvdata(pdev, data: a10r); |
107 | |
108 | return devm_reset_controller_register(dev: &pdev->dev, rcdev: &a10r->rcdev); |
109 | } |
110 | |
111 | static const struct of_device_id a10sr_reset_of_match[] = { |
112 | { .compatible = "altr,a10sr-reset" }, |
113 | { }, |
114 | }; |
115 | MODULE_DEVICE_TABLE(of, a10sr_reset_of_match); |
116 | |
117 | static struct platform_driver a10sr_reset_driver = { |
118 | .probe = a10sr_reset_probe, |
119 | .driver = { |
120 | .name = "altr_a10sr_reset" , |
121 | .of_match_table = a10sr_reset_of_match, |
122 | }, |
123 | }; |
124 | module_platform_driver(a10sr_reset_driver); |
125 | |
126 | MODULE_AUTHOR("Thor Thayer <thor.thayer@linux.intel.com>" ); |
127 | MODULE_DESCRIPTION("Altera Arria10 System Resource Reset Controller Driver" ); |
128 | MODULE_LICENSE("GPL v2" ); |
129 | |