Paul Walmsley | 2f334a3 | 2012-10-29 20:56:07 -0600 | [diff] [blame] | 1 | /* |
| 2 | * omap2-restart.c - code common to all OMAP2xxx machines. |
| 3 | * |
| 4 | * Copyright (C) 2012 Texas Instruments |
| 5 | * Paul Walmsley |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | */ |
| 11 | #include <linux/kernel.h> |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/clk.h> |
| 14 | #include <linux/io.h> |
| 15 | |
| 16 | #include "common.h" |
| 17 | #include "prm2xxx.h" |
| 18 | |
| 19 | /* |
| 20 | * reset_virt_prcm_set_ck, reset_sys_ck: pointers to the virt_prcm_set |
| 21 | * clock and the sys_ck. Used during the reset process |
| 22 | */ |
| 23 | static struct clk *reset_virt_prcm_set_ck, *reset_sys_ck; |
| 24 | |
| 25 | /* Reboot handling */ |
| 26 | |
| 27 | /** |
| 28 | * omap2xxx_restart - Set DPLL to bypass mode for reboot to work |
| 29 | * |
| 30 | * Set the DPLL to bypass so that reboot completes successfully. No |
| 31 | * return value. |
| 32 | */ |
| 33 | void omap2xxx_restart(char mode, const char *cmd) |
| 34 | { |
| 35 | u32 rate; |
| 36 | |
| 37 | rate = clk_get_rate(reset_sys_ck); |
| 38 | clk_set_rate(reset_virt_prcm_set_ck, rate); |
| 39 | |
| 40 | /* XXX Should save the cmd argument for use after the reboot */ |
| 41 | |
| 42 | omap2xxx_prm_dpll_reset(); /* never returns */ |
| 43 | while (1); |
| 44 | } |
| 45 | |
| 46 | /** |
| 47 | * omap2xxx_common_look_up_clks_for_reset - look up clocks needed for restart |
| 48 | * |
| 49 | * Some clocks need to be looked up in advance for the SoC restart |
| 50 | * operation to work - see omap2xxx_restart(). Returns -EINVAL upon |
| 51 | * error or 0 upon success. |
| 52 | */ |
| 53 | static int __init omap2xxx_common_look_up_clks_for_reset(void) |
| 54 | { |
| 55 | reset_virt_prcm_set_ck = clk_get(NULL, "virt_prcm_set"); |
| 56 | if (IS_ERR(reset_virt_prcm_set_ck)) |
| 57 | return -EINVAL; |
| 58 | |
| 59 | reset_sys_ck = clk_get(NULL, "sys_ck"); |
| 60 | if (IS_ERR(reset_sys_ck)) |
| 61 | return -EINVAL; |
| 62 | |
| 63 | return 0; |
| 64 | } |
| 65 | core_initcall(omap2xxx_common_look_up_clks_for_reset); |