xref: /OK3568_Linux_fs/u-boot/arch/arm/mach-aspeed/ast2500/clk_ast2500.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * Copyright (C) 2016 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 <asm/io.h>
10*4882a593Smuzhiyun #include <asm/arch/scu_ast2500.h>
11*4882a593Smuzhiyun 
ast_get_clk(struct udevice ** devp)12*4882a593Smuzhiyun int ast_get_clk(struct udevice **devp)
13*4882a593Smuzhiyun {
14*4882a593Smuzhiyun 	return uclass_get_device_by_driver(UCLASS_CLK,
15*4882a593Smuzhiyun 			DM_GET_DRIVER(aspeed_ast2500_scu), devp);
16*4882a593Smuzhiyun }
17*4882a593Smuzhiyun 
ast_get_scu(void)18*4882a593Smuzhiyun void *ast_get_scu(void)
19*4882a593Smuzhiyun {
20*4882a593Smuzhiyun 	struct ast2500_clk_priv *priv;
21*4882a593Smuzhiyun 	struct udevice *dev;
22*4882a593Smuzhiyun 	int ret;
23*4882a593Smuzhiyun 
24*4882a593Smuzhiyun 	ret = ast_get_clk(&dev);
25*4882a593Smuzhiyun 	if (ret)
26*4882a593Smuzhiyun 		return ERR_PTR(ret);
27*4882a593Smuzhiyun 
28*4882a593Smuzhiyun 	priv = dev_get_priv(dev);
29*4882a593Smuzhiyun 
30*4882a593Smuzhiyun 	return priv->scu;
31*4882a593Smuzhiyun }
32*4882a593Smuzhiyun 
ast_scu_unlock(struct ast2500_scu * scu)33*4882a593Smuzhiyun void ast_scu_unlock(struct ast2500_scu *scu)
34*4882a593Smuzhiyun {
35*4882a593Smuzhiyun 	writel(SCU_UNLOCK_VALUE, &scu->protection_key);
36*4882a593Smuzhiyun 	while (!readl(&scu->protection_key))
37*4882a593Smuzhiyun 		;
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun 
ast_scu_lock(struct ast2500_scu * scu)40*4882a593Smuzhiyun void ast_scu_lock(struct ast2500_scu *scu)
41*4882a593Smuzhiyun {
42*4882a593Smuzhiyun 	writel(~SCU_UNLOCK_VALUE, &scu->protection_key);
43*4882a593Smuzhiyun 	while (readl(&scu->protection_key))
44*4882a593Smuzhiyun 		;
45*4882a593Smuzhiyun }
46