1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2017 Google, Inc
4  * Copyright 2020 ASPEED Technology Inc.
5  */
6 
7 #include <common.h>
8 #include <dm.h>
9 #include <log.h>
10 #include <misc.h>
11 #include <reset.h>
12 #include <reset-uclass.h>
13 #include <linux/err.h>
14 #include <asm/io.h>
15 #include <asm/arch/scu_ast2500.h>
16 
17 struct ast2500_reset_priv {
18 	struct ast2500_scu *scu;
19 };
20 
ast2500_reset_request(struct reset_ctl * reset_ctl)21 static int ast2500_reset_request(struct reset_ctl *reset_ctl)
22 {
23 	debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__, reset_ctl,
24 	      reset_ctl->dev, reset_ctl->id);
25 
26 	return 0;
27 }
28 
ast2500_reset_free(struct reset_ctl * reset_ctl)29 static int ast2500_reset_free(struct reset_ctl *reset_ctl)
30 {
31 	debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__, reset_ctl,
32 	      reset_ctl->dev, reset_ctl->id);
33 
34 	return 0;
35 }
36 
ast2500_reset_assert(struct reset_ctl * reset_ctl)37 static int ast2500_reset_assert(struct reset_ctl *reset_ctl)
38 {
39 	struct ast2500_reset_priv *priv = dev_get_priv(reset_ctl->dev);
40 	struct ast2500_scu *scu = priv->scu;
41 
42 	debug("%s: reset_ctl->id: %lu\n", __func__, reset_ctl->id);
43 
44 	if (reset_ctl->id < 32)
45 		setbits_le32(&scu->sysreset_ctrl1, BIT(reset_ctl->id));
46 	else
47 		setbits_le32(&scu->sysreset_ctrl2, BIT(reset_ctl->id - 32));
48 
49 	return 0;
50 }
51 
ast2500_reset_deassert(struct reset_ctl * reset_ctl)52 static int ast2500_reset_deassert(struct reset_ctl *reset_ctl)
53 {
54 	struct ast2500_reset_priv *priv = dev_get_priv(reset_ctl->dev);
55 	struct ast2500_scu *scu = priv->scu;
56 
57 	debug("%s: reset_ctl->id: %lu\n", __func__, reset_ctl->id);
58 
59 	if (reset_ctl->id < 32)
60 		clrbits_le32(&scu->sysreset_ctrl1, BIT(reset_ctl->id));
61 	else
62 		clrbits_le32(&scu->sysreset_ctrl2, BIT(reset_ctl->id - 32));
63 
64 	return 0;
65 }
66 
ast2500_reset_probe(struct udevice * dev)67 static int ast2500_reset_probe(struct udevice *dev)
68 {
69 	int rc;
70 	struct ast2500_reset_priv *priv = dev_get_priv(dev);
71 	struct udevice *scu_dev;
72 
73 	/* get SCU base from clock device */
74 	rc = uclass_get_device_by_driver(UCLASS_CLK,
75 					 DM_DRIVER_GET(aspeed_ast2500_scu), &scu_dev);
76 	if (rc) {
77 		debug("%s: clock device not found, rc=%d\n", __func__, rc);
78 		return rc;
79 	}
80 
81 	priv->scu = devfdt_get_addr_ptr(scu_dev);
82 	if (IS_ERR_OR_NULL(priv->scu)) {
83 		debug("%s: invalid SCU base pointer\n", __func__);
84 		return PTR_ERR(priv->scu);
85 	}
86 
87 	return 0;
88 }
89 
90 static const struct udevice_id ast2500_reset_ids[] = {
91 	{ .compatible = "aspeed,ast2500-reset" },
92 	{ }
93 };
94 
95 struct reset_ops ast2500_reset_ops = {
96 	.request = ast2500_reset_request,
97 	.rfree = ast2500_reset_free,
98 	.rst_assert = ast2500_reset_assert,
99 	.rst_deassert = ast2500_reset_deassert,
100 };
101 
102 U_BOOT_DRIVER(ast2500_reset) = {
103 	.name = "ast2500_reset",
104 	.id = UCLASS_RESET,
105 	.of_match = ast2500_reset_ids,
106 	.probe = ast2500_reset_probe,
107 	.ops = &ast2500_reset_ops,
108 	.priv_auto	= sizeof(struct ast2500_reset_priv),
109 };
110