1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
4  *
5  * Derived from linux/arch/mips/bcm63xx/reset.c:
6  *	Copyright (C) 2012 Jonas Gorski <jonas.gorski@gmail.com>
7  */
8 
9 #include <common.h>
10 #include <dm.h>
11 #include <errno.h>
12 #include <log.h>
13 #include <malloc.h>
14 #include <reset-uclass.h>
15 #include <asm/io.h>
16 #include <linux/bitops.h>
17 #include <linux/delay.h>
18 
19 #define MAX_RESETS	32
20 
21 struct bcm6345_reset_priv {
22 	void __iomem *regs;
23 };
24 
bcm6345_reset_assert(struct reset_ctl * rst)25 static int bcm6345_reset_assert(struct reset_ctl *rst)
26 {
27 	struct bcm6345_reset_priv *priv = dev_get_priv(rst->dev);
28 
29 	clrbits_be32(priv->regs, BIT(rst->id));
30 	mdelay(20);
31 
32 	return 0;
33 }
34 
bcm6345_reset_deassert(struct reset_ctl * rst)35 static int bcm6345_reset_deassert(struct reset_ctl *rst)
36 {
37 	struct bcm6345_reset_priv *priv = dev_get_priv(rst->dev);
38 
39 	setbits_be32(priv->regs, BIT(rst->id));
40 	mdelay(20);
41 
42 	return 0;
43 }
44 
bcm6345_reset_free(struct reset_ctl * rst)45 static int bcm6345_reset_free(struct reset_ctl *rst)
46 {
47 	return 0;
48 }
49 
bcm6345_reset_request(struct reset_ctl * rst)50 static int bcm6345_reset_request(struct reset_ctl *rst)
51 {
52 	if (rst->id >= MAX_RESETS)
53 		return -EINVAL;
54 
55 	return bcm6345_reset_assert(rst);
56 }
57 
58 struct reset_ops bcm6345_reset_reset_ops = {
59 	.rfree = bcm6345_reset_free,
60 	.request = bcm6345_reset_request,
61 	.rst_assert = bcm6345_reset_assert,
62 	.rst_deassert = bcm6345_reset_deassert,
63 };
64 
65 static const struct udevice_id bcm6345_reset_ids[] = {
66 	{ .compatible = "brcm,bcm6345-reset" },
67 	{ /* sentinel */ }
68 };
69 
bcm6345_reset_probe(struct udevice * dev)70 static int bcm6345_reset_probe(struct udevice *dev)
71 {
72 	struct bcm6345_reset_priv *priv = dev_get_priv(dev);
73 
74 	priv->regs = dev_remap_addr(dev);
75 	if (!priv->regs)
76 		return -EINVAL;
77 
78 	return 0;
79 }
80 
81 U_BOOT_DRIVER(bcm6345_reset) = {
82 	.name = "bcm6345-reset",
83 	.id = UCLASS_RESET,
84 	.of_match = bcm6345_reset_ids,
85 	.ops = &bcm6345_reset_reset_ops,
86 	.probe = bcm6345_reset_probe,
87 	.priv_auto	= sizeof(struct bcm6345_reset_priv),
88 };
89