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8a56736a DH |
1 | /* |
2 | * Pistachio SoC Reset Controller driver | |
3 | * | |
4 | * Copyright (C) 2015 Imagination Technologies Ltd. | |
5 | * | |
6 | * Author: Damien Horsley <Damien.Horsley@imgtec.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms and conditions of the GNU General Public License, | |
10 | * version 2, as published by the Free Software Foundation. | |
11 | */ | |
12 | ||
13 | #include <linux/module.h> | |
14 | #include <linux/of.h> | |
15 | #include <linux/platform_device.h> | |
16 | #include <linux/regmap.h> | |
17 | #include <linux/reset-controller.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/mfd/syscon.h> | |
20 | ||
21 | #include <dt-bindings/reset/pistachio-resets.h> | |
22 | ||
23 | #define PISTACHIO_SOFT_RESET 0 | |
24 | ||
25 | struct pistachio_reset_data { | |
26 | struct reset_controller_dev rcdev; | |
27 | struct regmap *periph_regs; | |
28 | }; | |
29 | ||
30 | static inline int pistachio_reset_shift(unsigned long id) | |
31 | { | |
32 | switch (id) { | |
33 | case PISTACHIO_RESET_I2C0: | |
34 | case PISTACHIO_RESET_I2C1: | |
35 | case PISTACHIO_RESET_I2C2: | |
36 | case PISTACHIO_RESET_I2C3: | |
37 | case PISTACHIO_RESET_I2S_IN: | |
38 | case PISTACHIO_RESET_PRL_OUT: | |
39 | case PISTACHIO_RESET_SPDIF_OUT: | |
40 | case PISTACHIO_RESET_SPI: | |
41 | case PISTACHIO_RESET_PWM_PDM: | |
42 | case PISTACHIO_RESET_UART0: | |
43 | case PISTACHIO_RESET_UART1: | |
44 | case PISTACHIO_RESET_QSPI: | |
45 | case PISTACHIO_RESET_MDC: | |
46 | case PISTACHIO_RESET_SDHOST: | |
47 | case PISTACHIO_RESET_ETHERNET: | |
48 | case PISTACHIO_RESET_IR: | |
49 | case PISTACHIO_RESET_HASH: | |
50 | case PISTACHIO_RESET_TIMER: | |
51 | return id; | |
52 | case PISTACHIO_RESET_I2S_OUT: | |
53 | case PISTACHIO_RESET_SPDIF_IN: | |
54 | case PISTACHIO_RESET_EVT: | |
55 | return id + 6; | |
56 | case PISTACHIO_RESET_USB_H: | |
57 | case PISTACHIO_RESET_USB_PR: | |
58 | case PISTACHIO_RESET_USB_PHY_PR: | |
59 | case PISTACHIO_RESET_USB_PHY_PON: | |
60 | return id + 7; | |
61 | default: | |
62 | return -EINVAL; | |
63 | } | |
64 | } | |
65 | ||
66 | static int pistachio_reset_assert(struct reset_controller_dev *rcdev, | |
67 | unsigned long id) | |
68 | { | |
69 | struct pistachio_reset_data *rd; | |
70 | u32 mask; | |
71 | int shift; | |
72 | ||
73 | rd = container_of(rcdev, struct pistachio_reset_data, rcdev); | |
74 | shift = pistachio_reset_shift(id); | |
75 | if (shift < 0) | |
76 | return shift; | |
77 | mask = BIT(shift); | |
78 | ||
79 | return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET, | |
80 | mask, mask); | |
81 | } | |
82 | ||
83 | static int pistachio_reset_deassert(struct reset_controller_dev *rcdev, | |
84 | unsigned long id) | |
85 | { | |
86 | struct pistachio_reset_data *rd; | |
87 | u32 mask; | |
88 | int shift; | |
89 | ||
90 | rd = container_of(rcdev, struct pistachio_reset_data, rcdev); | |
91 | shift = pistachio_reset_shift(id); | |
92 | if (shift < 0) | |
93 | return shift; | |
94 | mask = BIT(shift); | |
95 | ||
96 | return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET, | |
97 | mask, 0); | |
98 | } | |
99 | ||
c0cc2609 | 100 | static const struct reset_control_ops pistachio_reset_ops = { |
8a56736a DH |
101 | .assert = pistachio_reset_assert, |
102 | .deassert = pistachio_reset_deassert, | |
103 | }; | |
104 | ||
105 | static int pistachio_reset_probe(struct platform_device *pdev) | |
106 | { | |
107 | struct pistachio_reset_data *rd; | |
108 | struct device *dev = &pdev->dev; | |
109 | struct device_node *np = pdev->dev.of_node; | |
110 | ||
111 | rd = devm_kzalloc(dev, sizeof(*rd), GFP_KERNEL); | |
112 | if (!rd) | |
113 | return -ENOMEM; | |
114 | ||
115 | rd->periph_regs = syscon_node_to_regmap(np->parent); | |
116 | if (IS_ERR(rd->periph_regs)) | |
117 | return PTR_ERR(rd->periph_regs); | |
118 | ||
119 | rd->rcdev.owner = THIS_MODULE; | |
120 | rd->rcdev.nr_resets = PISTACHIO_RESET_MAX + 1; | |
121 | rd->rcdev.ops = &pistachio_reset_ops; | |
122 | rd->rcdev.of_node = np; | |
123 | ||
124 | return reset_controller_register(&rd->rcdev); | |
125 | } | |
126 | ||
127 | static int pistachio_reset_remove(struct platform_device *pdev) | |
128 | { | |
129 | struct pistachio_reset_data *data = platform_get_drvdata(pdev); | |
130 | ||
131 | reset_controller_unregister(&data->rcdev); | |
132 | ||
133 | return 0; | |
134 | } | |
135 | ||
136 | static const struct of_device_id pistachio_reset_dt_ids[] = { | |
137 | { .compatible = "img,pistachio-reset", }, | |
138 | { /* sentinel */ }, | |
139 | }; | |
140 | MODULE_DEVICE_TABLE(of, pistachio_reset_dt_ids); | |
141 | ||
142 | static struct platform_driver pistachio_reset_driver = { | |
143 | .probe = pistachio_reset_probe, | |
144 | .remove = pistachio_reset_remove, | |
145 | .driver = { | |
146 | .name = "pistachio-reset", | |
147 | .of_match_table = pistachio_reset_dt_ids, | |
148 | }, | |
149 | }; | |
150 | module_platform_driver(pistachio_reset_driver); | |
151 | ||
152 | MODULE_AUTHOR("Damien Horsley <Damien.Horsley@imgtec.com>"); | |
153 | MODULE_DESCRIPTION("Pistacho Reset Controller Driver"); | |
154 | MODULE_LICENSE("GPL v2"); |