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