1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Pistachio SoC Reset Controller driver |
4 | * |
5 | * Copyright (C) 2015 Imagination Technologies Ltd. |
6 | * |
7 | * Author: Damien Horsley <Damien.Horsley@imgtec.com> |
8 | */ |
9 | |
10 | #include <linux/init.h> |
11 | #include <linux/of.h> |
12 | #include <linux/platform_device.h> |
13 | #include <linux/regmap.h> |
14 | #include <linux/reset-controller.h> |
15 | #include <linux/slab.h> |
16 | #include <linux/mfd/syscon.h> |
17 | |
18 | #include <dt-bindings/reset/pistachio-resets.h> |
19 | |
20 | #define PISTACHIO_SOFT_RESET 0 |
21 | |
22 | struct pistachio_reset_data { |
23 | struct reset_controller_dev rcdev; |
24 | struct regmap *periph_regs; |
25 | }; |
26 | |
27 | static inline int pistachio_reset_shift(unsigned long id) |
28 | { |
29 | switch (id) { |
30 | case PISTACHIO_RESET_I2C0: |
31 | case PISTACHIO_RESET_I2C1: |
32 | case PISTACHIO_RESET_I2C2: |
33 | case PISTACHIO_RESET_I2C3: |
34 | case PISTACHIO_RESET_I2S_IN: |
35 | case PISTACHIO_RESET_PRL_OUT: |
36 | case PISTACHIO_RESET_SPDIF_OUT: |
37 | case PISTACHIO_RESET_SPI: |
38 | case PISTACHIO_RESET_PWM_PDM: |
39 | case PISTACHIO_RESET_UART0: |
40 | case PISTACHIO_RESET_UART1: |
41 | case PISTACHIO_RESET_QSPI: |
42 | case PISTACHIO_RESET_MDC: |
43 | case PISTACHIO_RESET_SDHOST: |
44 | case PISTACHIO_RESET_ETHERNET: |
45 | case PISTACHIO_RESET_IR: |
46 | case PISTACHIO_RESET_HASH: |
47 | case PISTACHIO_RESET_TIMER: |
48 | return id; |
49 | case PISTACHIO_RESET_I2S_OUT: |
50 | case PISTACHIO_RESET_SPDIF_IN: |
51 | case PISTACHIO_RESET_EVT: |
52 | return id + 6; |
53 | case PISTACHIO_RESET_USB_H: |
54 | case PISTACHIO_RESET_USB_PR: |
55 | case PISTACHIO_RESET_USB_PHY_PR: |
56 | case PISTACHIO_RESET_USB_PHY_PON: |
57 | return id + 7; |
58 | default: |
59 | return -EINVAL; |
60 | } |
61 | } |
62 | |
63 | static int pistachio_reset_assert(struct reset_controller_dev *rcdev, |
64 | unsigned long id) |
65 | { |
66 | struct pistachio_reset_data *rd; |
67 | u32 mask; |
68 | int shift; |
69 | |
70 | rd = container_of(rcdev, struct pistachio_reset_data, rcdev); |
71 | shift = pistachio_reset_shift(id); |
72 | if (shift < 0) |
73 | return shift; |
74 | mask = BIT(shift); |
75 | |
76 | return regmap_update_bits(map: rd->periph_regs, PISTACHIO_SOFT_RESET, |
77 | mask, val: mask); |
78 | } |
79 | |
80 | static int pistachio_reset_deassert(struct reset_controller_dev *rcdev, |
81 | unsigned long id) |
82 | { |
83 | struct pistachio_reset_data *rd; |
84 | u32 mask; |
85 | int shift; |
86 | |
87 | rd = container_of(rcdev, struct pistachio_reset_data, rcdev); |
88 | shift = pistachio_reset_shift(id); |
89 | if (shift < 0) |
90 | return shift; |
91 | mask = BIT(shift); |
92 | |
93 | return regmap_update_bits(map: rd->periph_regs, PISTACHIO_SOFT_RESET, |
94 | mask, val: 0); |
95 | } |
96 | |
97 | static const struct reset_control_ops pistachio_reset_ops = { |
98 | .assert = pistachio_reset_assert, |
99 | .deassert = pistachio_reset_deassert, |
100 | }; |
101 | |
102 | static int pistachio_reset_probe(struct platform_device *pdev) |
103 | { |
104 | struct pistachio_reset_data *rd; |
105 | struct device *dev = &pdev->dev; |
106 | struct device_node *np = pdev->dev.of_node; |
107 | |
108 | rd = devm_kzalloc(dev, size: sizeof(*rd), GFP_KERNEL); |
109 | if (!rd) |
110 | return -ENOMEM; |
111 | |
112 | rd->periph_regs = syscon_node_to_regmap(np: np->parent); |
113 | if (IS_ERR(ptr: rd->periph_regs)) |
114 | return PTR_ERR(ptr: rd->periph_regs); |
115 | |
116 | rd->rcdev.owner = THIS_MODULE; |
117 | rd->rcdev.nr_resets = PISTACHIO_RESET_MAX + 1; |
118 | rd->rcdev.ops = &pistachio_reset_ops; |
119 | rd->rcdev.of_node = np; |
120 | |
121 | return devm_reset_controller_register(dev, rcdev: &rd->rcdev); |
122 | } |
123 | |
124 | static const struct of_device_id pistachio_reset_dt_ids[] = { |
125 | { .compatible = "img,pistachio-reset" , }, |
126 | { /* sentinel */ }, |
127 | }; |
128 | |
129 | static struct platform_driver pistachio_reset_driver = { |
130 | .probe = pistachio_reset_probe, |
131 | .driver = { |
132 | .name = "pistachio-reset" , |
133 | .of_match_table = pistachio_reset_dt_ids, |
134 | }, |
135 | }; |
136 | builtin_platform_driver(pistachio_reset_driver); |
137 | |