xref: /OK3568_Linux_fs/u-boot/drivers/reset/ast2500-reset.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * Copyright 2017 Google, Inc
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * SPDX-License-Identifier: GPL-2.0
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun #include <common.h>
8*4882a593Smuzhiyun #include <dm.h>
9*4882a593Smuzhiyun #include <misc.h>
10*4882a593Smuzhiyun #include <reset.h>
11*4882a593Smuzhiyun #include <reset-uclass.h>
12*4882a593Smuzhiyun #include <wdt.h>
13*4882a593Smuzhiyun #include <asm/io.h>
14*4882a593Smuzhiyun #include <asm/arch/scu_ast2500.h>
15*4882a593Smuzhiyun #include <asm/arch/wdt.h>
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun DECLARE_GLOBAL_DATA_PTR;
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun struct ast2500_reset_priv {
20*4882a593Smuzhiyun 	/* WDT used to perform resets. */
21*4882a593Smuzhiyun 	struct udevice *wdt;
22*4882a593Smuzhiyun 	struct ast2500_scu *scu;
23*4882a593Smuzhiyun };
24*4882a593Smuzhiyun 
ast2500_ofdata_to_platdata(struct udevice * dev)25*4882a593Smuzhiyun static int ast2500_ofdata_to_platdata(struct udevice *dev)
26*4882a593Smuzhiyun {
27*4882a593Smuzhiyun 	struct ast2500_reset_priv *priv = dev_get_priv(dev);
28*4882a593Smuzhiyun 	int ret;
29*4882a593Smuzhiyun 
30*4882a593Smuzhiyun 	ret = uclass_get_device_by_phandle(UCLASS_WDT, dev, "aspeed,wdt",
31*4882a593Smuzhiyun 					   &priv->wdt);
32*4882a593Smuzhiyun 	if (ret) {
33*4882a593Smuzhiyun 		debug("%s: can't find WDT for reset controller", __func__);
34*4882a593Smuzhiyun 		return ret;
35*4882a593Smuzhiyun 	}
36*4882a593Smuzhiyun 
37*4882a593Smuzhiyun 	return 0;
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun 
ast2500_reset_assert(struct reset_ctl * reset_ctl)40*4882a593Smuzhiyun static int ast2500_reset_assert(struct reset_ctl *reset_ctl)
41*4882a593Smuzhiyun {
42*4882a593Smuzhiyun 	struct ast2500_reset_priv *priv = dev_get_priv(reset_ctl->dev);
43*4882a593Smuzhiyun 	u32 reset_mode, reset_mask;
44*4882a593Smuzhiyun 	bool reset_sdram;
45*4882a593Smuzhiyun 	int ret;
46*4882a593Smuzhiyun 
47*4882a593Smuzhiyun 	/*
48*4882a593Smuzhiyun 	 * To reset SDRAM, a specifal flag in SYSRESET register
49*4882a593Smuzhiyun 	 * needs to be enabled first
50*4882a593Smuzhiyun 	 */
51*4882a593Smuzhiyun 	reset_mode = ast_reset_mode_from_flags(reset_ctl->id);
52*4882a593Smuzhiyun 	reset_mask = ast_reset_mask_from_flags(reset_ctl->id);
53*4882a593Smuzhiyun 	reset_sdram = reset_mode == WDT_CTRL_RESET_SOC &&
54*4882a593Smuzhiyun 		(reset_mask & WDT_RESET_SDRAM);
55*4882a593Smuzhiyun 
56*4882a593Smuzhiyun 	if (reset_sdram) {
57*4882a593Smuzhiyun 		ast_scu_unlock(priv->scu);
58*4882a593Smuzhiyun 		setbits_le32(&priv->scu->sysreset_ctrl1,
59*4882a593Smuzhiyun 			     SCU_SYSRESET_SDRAM_WDT);
60*4882a593Smuzhiyun 		ret = wdt_expire_now(priv->wdt, reset_ctl->id);
61*4882a593Smuzhiyun 		clrbits_le32(&priv->scu->sysreset_ctrl1,
62*4882a593Smuzhiyun 			     SCU_SYSRESET_SDRAM_WDT);
63*4882a593Smuzhiyun 		ast_scu_lock(priv->scu);
64*4882a593Smuzhiyun 	} else {
65*4882a593Smuzhiyun 		ret = wdt_expire_now(priv->wdt, reset_ctl->id);
66*4882a593Smuzhiyun 	}
67*4882a593Smuzhiyun 
68*4882a593Smuzhiyun 	return ret;
69*4882a593Smuzhiyun }
70*4882a593Smuzhiyun 
ast2500_reset_request(struct reset_ctl * reset_ctl)71*4882a593Smuzhiyun static int ast2500_reset_request(struct reset_ctl *reset_ctl)
72*4882a593Smuzhiyun {
73*4882a593Smuzhiyun 	debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__, reset_ctl,
74*4882a593Smuzhiyun 	      reset_ctl->dev, reset_ctl->id);
75*4882a593Smuzhiyun 
76*4882a593Smuzhiyun 	return 0;
77*4882a593Smuzhiyun }
78*4882a593Smuzhiyun 
ast2500_reset_probe(struct udevice * dev)79*4882a593Smuzhiyun static int ast2500_reset_probe(struct udevice *dev)
80*4882a593Smuzhiyun {
81*4882a593Smuzhiyun 	struct ast2500_reset_priv *priv = dev_get_priv(dev);
82*4882a593Smuzhiyun 
83*4882a593Smuzhiyun 	priv->scu = ast_get_scu();
84*4882a593Smuzhiyun 
85*4882a593Smuzhiyun 	return 0;
86*4882a593Smuzhiyun }
87*4882a593Smuzhiyun 
88*4882a593Smuzhiyun static const struct udevice_id ast2500_reset_ids[] = {
89*4882a593Smuzhiyun 	{ .compatible = "aspeed,ast2500-reset" },
90*4882a593Smuzhiyun 	{ }
91*4882a593Smuzhiyun };
92*4882a593Smuzhiyun 
93*4882a593Smuzhiyun struct reset_ops ast2500_reset_ops = {
94*4882a593Smuzhiyun 	.rst_assert = ast2500_reset_assert,
95*4882a593Smuzhiyun 	.request = ast2500_reset_request,
96*4882a593Smuzhiyun };
97*4882a593Smuzhiyun 
98*4882a593Smuzhiyun U_BOOT_DRIVER(ast2500_reset) = {
99*4882a593Smuzhiyun 	.name		= "ast2500_reset",
100*4882a593Smuzhiyun 	.id		= UCLASS_RESET,
101*4882a593Smuzhiyun 	.of_match = ast2500_reset_ids,
102*4882a593Smuzhiyun 	.probe = ast2500_reset_probe,
103*4882a593Smuzhiyun 	.ops = &ast2500_reset_ops,
104*4882a593Smuzhiyun 	.ofdata_to_platdata = ast2500_ofdata_to_platdata,
105*4882a593Smuzhiyun 	.priv_auto_alloc_size = sizeof(struct ast2500_reset_priv),
106*4882a593Smuzhiyun };
107