xref: /openbmc/u-boot/drivers/reset/reset-sunxi.c (revision 04b24965)
1 // SPDX-License-Identifier: (GPL-2.0+ OR MIT)
2 /*
3  * Copyright (C) 2018 Amarula Solutions.
4  * Author: Jagan Teki <jagan@amarulasolutions.com>
5  */
6 
7 #include <common.h>
8 #include <dm.h>
9 #include <errno.h>
10 #include <reset-uclass.h>
11 #include <asm/io.h>
12 #include <dm/lists.h>
13 #include <linux/log2.h>
14 #include <asm/arch/ccu.h>
15 
16 struct sunxi_reset_priv {
17 	void *base;
18 	ulong count;
19 	const struct ccu_desc *desc;
20 };
21 
22 static const struct ccu_reset *priv_to_reset(struct sunxi_reset_priv *priv,
23 					     unsigned long id)
24 {
25 	return	&priv->desc->resets[id];
26 }
27 
28 static int sunxi_reset_request(struct reset_ctl *reset_ctl)
29 {
30 	struct sunxi_reset_priv *priv = dev_get_priv(reset_ctl->dev);
31 
32 	debug("%s: (RST#%ld)\n", __func__, reset_ctl->id);
33 
34 	if (reset_ctl->id >= priv->count)
35 		return -EINVAL;
36 
37 	return 0;
38 }
39 
40 static int sunxi_reset_free(struct reset_ctl *reset_ctl)
41 {
42 	debug("%s: (RST#%ld)\n", __func__, reset_ctl->id);
43 
44 	return 0;
45 }
46 
47 static int sunxi_set_reset(struct reset_ctl *reset_ctl, bool on)
48 {
49 	struct sunxi_reset_priv *priv = dev_get_priv(reset_ctl->dev);
50 	const struct ccu_reset *reset = priv_to_reset(priv, reset_ctl->id);
51 	u32 reg;
52 
53 	if (!(reset->flags & CCU_RST_F_IS_VALID)) {
54 		printf("%s: (RST#%ld) unhandled\n", __func__, reset_ctl->id);
55 		return 0;
56 	}
57 
58 	debug("%s: (RST#%ld) off#0x%x, BIT(%d)\n", __func__,
59 	      reset_ctl->id, reset->off, ilog2(reset->bit));
60 
61 	reg = readl(priv->base + reset->off);
62 	if (on)
63 		reg |= reset->bit;
64 	else
65 		reg &= ~reset->bit;
66 
67 	writel(reg, priv->base + reset->off);
68 
69 	return 0;
70 }
71 
72 static int sunxi_reset_assert(struct reset_ctl *reset_ctl)
73 {
74 	return sunxi_set_reset(reset_ctl, false);
75 }
76 
77 static int sunxi_reset_deassert(struct reset_ctl *reset_ctl)
78 {
79 	return sunxi_set_reset(reset_ctl, true);
80 }
81 
82 struct reset_ops sunxi_reset_ops = {
83 	.request = sunxi_reset_request,
84 	.free = sunxi_reset_free,
85 	.rst_assert = sunxi_reset_assert,
86 	.rst_deassert = sunxi_reset_deassert,
87 };
88 
89 static int sunxi_reset_probe(struct udevice *dev)
90 {
91 	struct sunxi_reset_priv *priv = dev_get_priv(dev);
92 
93 	priv->base = dev_read_addr_ptr(dev);
94 
95 	return 0;
96 }
97 
98 int sunxi_reset_bind(struct udevice *dev, ulong count)
99 {
100 	struct udevice *rst_dev;
101 	struct sunxi_reset_priv *priv;
102 	int ret;
103 
104 	ret = device_bind_driver_to_node(dev, "sunxi_reset", "reset",
105 					 dev_ofnode(dev), &rst_dev);
106 	if (ret) {
107 		debug("failed to bind sunxi_reset driver (ret=%d)\n", ret);
108 		return ret;
109 	}
110 	priv = malloc(sizeof(struct sunxi_reset_priv));
111 	priv->count = count;
112 	priv->desc = (const struct ccu_desc *)dev_get_driver_data(dev);
113 	rst_dev->priv = priv;
114 
115 	return 0;
116 }
117 
118 U_BOOT_DRIVER(sunxi_reset) = {
119 	.name		= "sunxi_reset",
120 	.id		= UCLASS_RESET,
121 	.ops		= &sunxi_reset_ops,
122 	.probe		= sunxi_reset_probe,
123 	.priv_auto_alloc_size = sizeof(struct sunxi_reset_priv),
124 };
125