xref: /openbmc/u-boot/drivers/reset/aspeed/reset-ast2500.c (revision e6b48dfde594339538ac59361a838ab3b3d7fdd8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2017 Google, Inc
4  */
5 
6 #include <common.h>
7 #include <dm.h>
8 #include <misc.h>
9 #include <reset.h>
10 #include <reset-uclass.h>
11 #include <wdt.h>
12 #include <asm/io.h>
13 #include <asm/arch/wdt.h>
14 #include <asm/arch/scu_ast2500.h>
15 
16 struct ast2500_reset_priv {
17 	/* WDT used to perform resets. */
18 	struct udevice *wdt;
19 	struct ast2500_scu *scu;
20 };
21 
22 static int ast2500_reset_assert(struct reset_ctl *reset_ctl)
23 {
24 	struct ast2500_reset_priv *priv = dev_get_priv(reset_ctl->dev);
25 	struct ast2500_scu *scu = priv->scu;
26 	u32 reset_mode, reset_mask;
27 	bool reset_sdram;
28 	int ret = 0;
29 
30 	printf("ast2500_reset_assert reset_ctl->id %d \n", reset_ctl->id);
31 	/*
32 	 * To reset SDRAM, a specifal flag in SYSRESET register
33 	 * needs to be enabled first
34 	 */
35 	reset_mode = ast_reset_mode_from_flags(reset_ctl->id);
36 	reset_mask = ast_reset_mask_from_flags(reset_ctl->id);
37 	reset_sdram = reset_mode == WDT_CTRL_RESET_SOC &&
38 		(reset_mask & WDT_RESET_SDRAM);
39 #if 0
40 	if (reset_sdram) {
41 		ast_scu_unlock(priv->scu);
42 		setbits_le32(&priv->scu->sysreset_ctrl1,
43 			     SCU_SYSRESET_SDRAM_WDT);
44 		ret = wdt_expire_now(priv->wdt, reset_ctl->id);
45 		clrbits_le32(&priv->scu->sysreset_ctrl1,
46 			     SCU_SYSRESET_SDRAM_WDT);
47 		ast_scu_lock(priv->scu);
48 	} else {
49 		ret = wdt_expire_now(priv->wdt, reset_ctl->id);
50 	}
51 #endif
52 	if(reset_ctl->id >= 32)
53 		setbits_le32(scu->sysreset_ctrl1 , BIT(reset_ctl->id - 32));
54 	else
55 		setbits_le32(scu->sysreset_ctrl1 , BIT(reset_ctl->id));
56 
57 	return ret;
58 }
59 
60 static int ast2500_reset_request(struct reset_ctl *reset_ctl)
61 {
62 	debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__, reset_ctl,
63 	      reset_ctl->dev, reset_ctl->id);
64 
65 	return 0;
66 }
67 
68 static int ast2500_reset_probe(struct udevice *dev)
69 {
70 	struct ast2500_reset_priv *priv = dev_get_priv(dev);
71 	struct udevice *clk_dev;
72 	int ret = 0;
73 
74 	/* find SCU base address from clock device */
75 	ret = uclass_get_device_by_driver(UCLASS_CLK, DM_GET_DRIVER(aspeed_scu),
76                                           &clk_dev);
77     if (ret) {
78             debug("clock device not found\n");
79             return ret;
80     }
81 
82 	priv->scu = devfdt_get_addr_ptr(clk_dev);
83 	if (IS_ERR(priv->scu)) {
84 	        debug("%s(): can't get SCU\n", __func__);
85 	        return PTR_ERR(priv->scu);
86 	}
87 
88 	return 0;
89 }
90 static int aspeed_ofdata_to_platdata(struct udevice *dev)
91 {
92 	struct ast2500_reset_priv *priv = dev_get_priv(dev);
93 	int ret;
94 
95 	ret = uclass_get_device_by_phandle(UCLASS_WDT, dev, "aspeed,wdt",
96 					   &priv->wdt);
97 	if (ret) {
98 		debug("%s: can't find WDT for reset controller", __func__);
99 		return ret;
100 	}
101 
102 	return 0;
103 }
104 
105 static const struct udevice_id aspeed_reset_ids[] = {
106 	{ .compatible = "aspeed,ast2500-reset" },
107 	{ }
108 };
109 
110 struct reset_ops aspeed_reset_ops = {
111 	.rst_assert = ast2500_reset_assert,
112 	.request = ast2500_reset_request,
113 };
114 
115 U_BOOT_DRIVER(aspeed_reset) = {
116 	.name		= "aspeed_reset",
117 	.id		= UCLASS_RESET,
118 	.of_match = aspeed_reset_ids,
119 	.probe = ast2500_reset_probe,
120 	.ops = &aspeed_reset_ops,
121 	.ofdata_to_platdata = aspeed_ofdata_to_platdata,
122 	.priv_auto_alloc_size = sizeof(struct ast2500_reset_priv),
123 };
124