xref: /openbmc/linux/drivers/clk/ti/clk-43xx.c (revision 131ee08f)
1 /*
2  * AM43XX Clock init
3  *
4  * Copyright (C) 2013 Texas Instruments, Inc
5  *     Tero Kristo (t-kristo@ti.com)
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation version 2.
10  *
11  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
12  * kind, whether express or implied; without even the implied warranty
13  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/list.h>
19 #include <linux/clk.h>
20 #include <linux/clk-provider.h>
21 #include <linux/clk/ti.h>
22 #include <dt-bindings/clock/am4.h>
23 
24 #include "clock.h"
25 
26 int __init am43xx_dt_clk_init(void)
27 {
28 	struct clk *clk1, *clk2;
29 
30 	ti_dt_clocks_register(am43xx_compat_clks);
31 
32 	omap2_clk_disable_autoidle_all();
33 
34 	ti_clk_add_aliases();
35 
36 	/*
37 	 * cpsw_cpts_rft_clk  has got the choice of 3 clocksources
38 	 * dpll_core_m4_ck, dpll_core_m5_ck and dpll_disp_m2_ck.
39 	 * By default dpll_core_m4_ck is selected, witn this as clock
40 	 * source the CPTS doesnot work properly. It gives clockcheck errors
41 	 * while running PTP.
42 	 * clockcheck: clock jumped backward or running slower than expected!
43 	 * By selecting dpll_core_m5_ck as the clocksource fixes this issue.
44 	 * In AM335x dpll_core_m5_ck is the default clocksource.
45 	 */
46 	clk1 = clk_get_sys(NULL, "cpsw_cpts_rft_clk");
47 	clk2 = clk_get_sys(NULL, "dpll_core_m5_ck");
48 	clk_set_parent(clk1, clk2);
49 
50 	return 0;
51 }
52