1 /*
2 * Copyright 2017 Google, Inc
3 *
4 * SPDX-License-Identifier: GPL-2.0
5 */
6
7 #include <common.h>
8 #include <dm.h>
9 #include <misc.h>
10 #include <reset.h>
11 #include <reset-uclass.h>
12 #include <wdt.h>
13 #include <asm/io.h>
14 #include <asm/arch/scu_ast2500.h>
15 #include <asm/arch/wdt.h>
16
17 DECLARE_GLOBAL_DATA_PTR;
18
19 struct ast2500_reset_priv {
20 /* WDT used to perform resets. */
21 struct udevice *wdt;
22 struct ast2500_scu *scu;
23 };
24
ast2500_ofdata_to_platdata(struct udevice * dev)25 static int ast2500_ofdata_to_platdata(struct udevice *dev)
26 {
27 struct ast2500_reset_priv *priv = dev_get_priv(dev);
28 int ret;
29
30 ret = uclass_get_device_by_phandle(UCLASS_WDT, dev, "aspeed,wdt",
31 &priv->wdt);
32 if (ret) {
33 debug("%s: can't find WDT for reset controller", __func__);
34 return ret;
35 }
36
37 return 0;
38 }
39
ast2500_reset_assert(struct reset_ctl * reset_ctl)40 static int ast2500_reset_assert(struct reset_ctl *reset_ctl)
41 {
42 struct ast2500_reset_priv *priv = dev_get_priv(reset_ctl->dev);
43 u32 reset_mode, reset_mask;
44 bool reset_sdram;
45 int ret;
46
47 /*
48 * To reset SDRAM, a specifal flag in SYSRESET register
49 * needs to be enabled first
50 */
51 reset_mode = ast_reset_mode_from_flags(reset_ctl->id);
52 reset_mask = ast_reset_mask_from_flags(reset_ctl->id);
53 reset_sdram = reset_mode == WDT_CTRL_RESET_SOC &&
54 (reset_mask & WDT_RESET_SDRAM);
55
56 if (reset_sdram) {
57 ast_scu_unlock(priv->scu);
58 setbits_le32(&priv->scu->sysreset_ctrl1,
59 SCU_SYSRESET_SDRAM_WDT);
60 ret = wdt_expire_now(priv->wdt, reset_ctl->id);
61 clrbits_le32(&priv->scu->sysreset_ctrl1,
62 SCU_SYSRESET_SDRAM_WDT);
63 ast_scu_lock(priv->scu);
64 } else {
65 ret = wdt_expire_now(priv->wdt, reset_ctl->id);
66 }
67
68 return ret;
69 }
70
ast2500_reset_request(struct reset_ctl * reset_ctl)71 static int ast2500_reset_request(struct reset_ctl *reset_ctl)
72 {
73 debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__, reset_ctl,
74 reset_ctl->dev, reset_ctl->id);
75
76 return 0;
77 }
78
ast2500_reset_probe(struct udevice * dev)79 static int ast2500_reset_probe(struct udevice *dev)
80 {
81 struct ast2500_reset_priv *priv = dev_get_priv(dev);
82
83 priv->scu = ast_get_scu();
84
85 return 0;
86 }
87
88 static const struct udevice_id ast2500_reset_ids[] = {
89 { .compatible = "aspeed,ast2500-reset" },
90 { }
91 };
92
93 struct reset_ops ast2500_reset_ops = {
94 .rst_assert = ast2500_reset_assert,
95 .request = ast2500_reset_request,
96 };
97
98 U_BOOT_DRIVER(ast2500_reset) = {
99 .name = "ast2500_reset",
100 .id = UCLASS_RESET,
101 .of_match = ast2500_reset_ids,
102 .probe = ast2500_reset_probe,
103 .ops = &ast2500_reset_ops,
104 .ofdata_to_platdata = ast2500_ofdata_to_platdata,
105 .priv_auto_alloc_size = sizeof(struct ast2500_reset_priv),
106 };
107