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@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 39const char * 40meson_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