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 */ 21 static 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 */ 31 void 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 */ 50 static 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 } 62 omap_postcore_initcall(omap2xxx_common_look_up_clks_for_reset); 63