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      1 /* $NetBSD: imx_ccm_mux.c,v 1.1 2020/12/23 14:42:38 skrll Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2020 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: imx_ccm_mux.c,v 1.1 2020/12/23 14:42:38 skrll Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/bus.h>
     34 
     35 #include <dev/clk/clk_backend.h>
     36 
     37 #include <arm/nxp/imx_ccm.h>
     38 
     39 #include <dev/fdt/fdtvar.h>
     40 
     41 const char *
     42 imx_ccm_mux_get_parent(struct imx_ccm_softc *sc,
     43     struct imx_ccm_clk *clk)
     44 {
     45 	struct imx_ccm_mux *mux = &clk->u.mux;
     46 
     47 	KASSERT(clk->type == IMX_CCM_MUX);
     48 
     49 	const uint32_t val = CCM_READ(sc, clk->regidx, mux->reg);
     50 	const u_int sel = __SHIFTOUT(val, mux->sel);
     51 
     52 	if (sel >= mux->nparents)
     53 		return NULL;
     54 
     55 	return mux->parents[sel];
     56 }
     57 
     58 int
     59 imx_ccm_mux_set_parent(struct imx_ccm_softc *sc,
     60     struct imx_ccm_clk *clk, const char *parent)
     61 {
     62 	struct imx_ccm_mux *mux = &clk->u.mux;
     63 	uint32_t val;
     64 
     65 	KASSERT(clk->type == IMX_CCM_MUX);
     66 
     67 	for (u_int sel = 0; sel < mux->nparents; sel++) {
     68 		if (strcmp(mux->parents[sel], parent) == 0) {
     69 			val = CCM_READ(sc, clk->regidx, mux->reg);
     70 			val &= ~mux->sel;
     71 			val |= __SHIFTIN(sel, mux->sel);
     72 			CCM_WRITE(sc, clk->regidx, mux->reg, val);
     73 			return 0;
     74 		}
     75 	}
     76 
     77 	return EINVAL;
     78 }
     79