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      1 /* $NetBSD: meson_clk_fixed_factor.c,v 1.1 2019/01/19 20:56:03 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_fixed_factor.c,v 1.1 2019/01/19 20:56:03 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 static u_int
     40 meson_clk_fixed_factor_get_parent_rate(struct clk *clkp)
     41 {
     42 	struct clk *clkp_parent;
     43 
     44 	clkp_parent = clk_get_parent(clkp);
     45 	if (clkp_parent == NULL)
     46 		return 0;
     47 
     48 	return clk_get_rate(clkp_parent);
     49 }
     50 
     51 u_int
     52 meson_clk_fixed_factor_get_rate(struct meson_clk_softc *sc,
     53     struct meson_clk_clk *clk)
     54 {
     55 	struct meson_clk_fixed_factor *fixed_factor = &clk->u.fixed_factor;
     56 	struct clk *clkp = &clk->base;
     57 
     58 	KASSERT(clk->type == MESON_CLK_FIXED_FACTOR);
     59 
     60 	const u_int p_rate = meson_clk_fixed_factor_get_parent_rate(clkp);
     61 	if (p_rate == 0)
     62 		return 0;
     63 
     64 	return (u_int)(((uint64_t)p_rate * fixed_factor->mult) / fixed_factor->div);
     65 }
     66 
     67 static int
     68 meson_clk_fixed_factor_set_parent_rate(struct clk *clkp, u_int rate)
     69 {
     70 	struct clk *clkp_parent;
     71 
     72 	clkp_parent = clk_get_parent(clkp);
     73 	if (clkp_parent == NULL)
     74 		return ENXIO;
     75 
     76 	return clk_set_rate(clkp_parent, rate);
     77 }
     78 
     79 int
     80 meson_clk_fixed_factor_set_rate(struct meson_clk_softc *sc,
     81     struct meson_clk_clk *clk, u_int rate)
     82 {
     83 	struct meson_clk_fixed_factor *fixed_factor = &clk->u.fixed_factor;
     84 	struct clk *clkp = &clk->base;
     85 
     86 	KASSERT(clk->type == MESON_CLK_FIXED_FACTOR);
     87 
     88 	rate *= fixed_factor->div;
     89 	rate /= fixed_factor->mult;
     90 
     91 	return meson_clk_fixed_factor_set_parent_rate(clkp, rate);
     92 }
     93 
     94 const char *
     95 meson_clk_fixed_factor_get_parent(struct meson_clk_softc *sc,
     96     struct meson_clk_clk *clk)
     97 {
     98 	struct meson_clk_fixed_factor *fixed_factor = &clk->u.fixed_factor;
     99 
    100 	KASSERT(clk->type == MESON_CLK_FIXED_FACTOR);
    101 
    102 	return fixed_factor->parent;
    103 }
    104