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android-review.linaro.org / kernel / hikey-linaro / bf7ef8f2d57cd1f5f1846dd58ff9309efad58252 / . / drivers / reset / reset-pistachio.c
blob: bbc4c06dd33b7542b1b1478e46201e9024237682 [file] [log] [blame]
Damien Horsley8a567362016-01-18 13:12:38 +0000[diff] [blame]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
25struct pistachio_reset_data {
26 struct reset_controller_dev rcdev;
27 struct regmap *periph_regs;
28};
29
30static 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
66static 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
83static 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
Philipp Zabelc0cc2602016-02-05 16:49:34 +0100[diff] [blame]100static const struct reset_control_ops pistachio_reset_ops = {
Damien Horsley8a567362016-01-18 13:12:38 +0000[diff] [blame]101 .assert = pistachio_reset_assert,
102 .deassert = pistachio_reset_deassert,
103};
104
105static 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
Masahiro Yamada1b1447f2016-05-01 19:37:00 +0900[diff] [blame]124 return devm_reset_controller_register(dev, &rd->rcdev);
Damien Horsley8a567362016-01-18 13:12:38 +0000[diff] [blame]125}
126
127static const struct of_device_id pistachio_reset_dt_ids[] = {
128 { .compatible = "img,pistachio-reset", },
129 { /* sentinel */ },
130};
131MODULE_DEVICE_TABLE(of, pistachio_reset_dt_ids);
132
133static struct platform_driver pistachio_reset_driver = {
134 .probe = pistachio_reset_probe,
Damien Horsley8a567362016-01-18 13:12:38 +0000[diff] [blame]135 .driver = {
136 .name = "pistachio-reset",
137 .of_match_table = pistachio_reset_dt_ids,
138 },
139};
140module_platform_driver(pistachio_reset_driver);
141
142MODULE_AUTHOR("Damien Horsley <Damien.Horsley@imgtec.com>");
143MODULE_DESCRIPTION("Pistacho Reset Controller Driver");
144MODULE_LICENSE("GPL v2");