xref: /OK3568_Linux_fs/kernel/arch/arm/mach-omap2/omap2-restart.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * omap2-restart.c - code common to all OMAP2xxx machines.
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * Copyright (C) 2012 Texas Instruments
6*4882a593Smuzhiyun  * Paul Walmsley
7*4882a593Smuzhiyun  */
8*4882a593Smuzhiyun #include <linux/kernel.h>
9*4882a593Smuzhiyun #include <linux/init.h>
10*4882a593Smuzhiyun #include <linux/clk.h>
11*4882a593Smuzhiyun #include <linux/io.h>
12*4882a593Smuzhiyun 
13*4882a593Smuzhiyun #include "soc.h"
14*4882a593Smuzhiyun #include "common.h"
15*4882a593Smuzhiyun #include "prm.h"
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun /*
18*4882a593Smuzhiyun  * reset_virt_prcm_set_ck, reset_sys_ck: pointers to the virt_prcm_set
19*4882a593Smuzhiyun  * clock and the sys_ck.  Used during the reset process
20*4882a593Smuzhiyun  */
21*4882a593Smuzhiyun static struct clk *reset_virt_prcm_set_ck, *reset_sys_ck;
22*4882a593Smuzhiyun 
23*4882a593Smuzhiyun /* Reboot handling */
24*4882a593Smuzhiyun 
25*4882a593Smuzhiyun /**
26*4882a593Smuzhiyun  * omap2xxx_restart - Set DPLL to bypass mode for reboot to work
27*4882a593Smuzhiyun  *
28*4882a593Smuzhiyun  * Set the DPLL to bypass so that reboot completes successfully.  No
29*4882a593Smuzhiyun  * return value.
30*4882a593Smuzhiyun  */
omap2xxx_restart(enum reboot_mode mode,const char * cmd)31*4882a593Smuzhiyun void omap2xxx_restart(enum reboot_mode mode, const char *cmd)
32*4882a593Smuzhiyun {
33*4882a593Smuzhiyun 	u32 rate;
34*4882a593Smuzhiyun 
35*4882a593Smuzhiyun 	rate = clk_get_rate(reset_sys_ck);
36*4882a593Smuzhiyun 	clk_set_rate(reset_virt_prcm_set_ck, rate);
37*4882a593Smuzhiyun 
38*4882a593Smuzhiyun 	/* XXX Should save the cmd argument for use after the reboot */
39*4882a593Smuzhiyun 
40*4882a593Smuzhiyun 	omap_prm_reset_system();
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun 
43*4882a593Smuzhiyun /**
44*4882a593Smuzhiyun  * omap2xxx_common_look_up_clks_for_reset - look up clocks needed for restart
45*4882a593Smuzhiyun  *
46*4882a593Smuzhiyun  * Some clocks need to be looked up in advance for the SoC restart
47*4882a593Smuzhiyun  * operation to work - see omap2xxx_restart().  Returns -EINVAL upon
48*4882a593Smuzhiyun  * error or 0 upon success.
49*4882a593Smuzhiyun  */
omap2xxx_common_look_up_clks_for_reset(void)50*4882a593Smuzhiyun static int __init omap2xxx_common_look_up_clks_for_reset(void)
51*4882a593Smuzhiyun {
52*4882a593Smuzhiyun 	reset_virt_prcm_set_ck = clk_get(NULL, "virt_prcm_set");
53*4882a593Smuzhiyun 	if (IS_ERR(reset_virt_prcm_set_ck))
54*4882a593Smuzhiyun 		return -EINVAL;
55*4882a593Smuzhiyun 
56*4882a593Smuzhiyun 	reset_sys_ck = clk_get(NULL, "sys_ck");
57*4882a593Smuzhiyun 	if (IS_ERR(reset_sys_ck))
58*4882a593Smuzhiyun 		return -EINVAL;
59*4882a593Smuzhiyun 
60*4882a593Smuzhiyun 	return 0;
61*4882a593Smuzhiyun }
62*4882a593Smuzhiyun omap_postcore_initcall(omap2xxx_common_look_up_clks_for_reset);
63