Home | History | Annotate | Line # | Download | only in amlogic 
      1 /* $NetBSD: meson_clk_mux.c,v 1.2 2019/02/25 19:30:17 jmcneill Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2017-2019 Jared McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: meson_clk_mux.c,v 1.2 2019/02/25 19:30:17 jmcneill Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/bus.h>
     34 
     35 #include <dev/clk/clk_backend.h>
     36 
     37 #include <arm/amlogic/meson_clk.h>
     38 
     39 const char *
     40 meson_clk_mux_get_parent(struct meson_clk_softc *sc, struct meson_clk_clk *clk)
     41 {
     42 	struct meson_clk_mux *mux = &clk->u.mux;
     43 	uint32_t val;
     44 	u_int sel;
     45 
     46 	KASSERT(clk->type == MESON_CLK_MUX);
     47 
     48 	CLK_LOCK(sc);
     49 	val = CLK_READ(sc, mux->reg);
     50 	CLK_UNLOCK(sc);
     51 
     52 	sel = __SHIFTOUT(val, mux->sel);
     53 	if (sel >= mux->nparents)
     54 		return NULL;
     55 
     56 	return mux->parents[sel];
     57 }
     58