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sunxi_ccu_div.c revision 1.2.2.2 
      1 /* $NetBSD: sunxi_ccu_div.c,v 1.2.2.2 2017/08/28 17:51:32 skrll Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2017 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: sunxi_ccu_div.c,v 1.2.2.2 2017/08/28 17:51:32 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/sunxi/sunxi_ccu.h>
     38 
     39 u_int
     40 sunxi_ccu_div_get_rate(struct sunxi_ccu_softc *sc,
     41     struct sunxi_ccu_clk *clk)
     42 {
     43 	struct sunxi_ccu_div *div = &clk->u.div;
     44 	struct clk *clkp, *clkp_parent;
     45 	u_int rate, ratio;
     46 	uint32_t val;
     47 
     48 	KASSERT(clk->type == SUNXI_CCU_DIV);
     49 
     50 	clkp = &clk->base;
     51 	clkp_parent = clk_get_parent(clkp);
     52 	if (clkp_parent == NULL)
     53 		return 0;
     54 
     55 	rate = clk_get_rate(clkp_parent);
     56 	if (rate == 0)
     57 		return 0;
     58 
     59 	val = CCU_READ(sc, div->reg);
     60 	if (div->div)
     61 		ratio = __SHIFTOUT(val, div->div);
     62 	else
     63 		ratio = 0;
     64 
     65 	if ((div->flags & SUNXI_CCU_DIV_ZERO_IS_ONE) != 0 && ratio == 0)
     66 		ratio = 1;
     67 	if (div->flags & SUNXI_CCU_DIV_POWER_OF_TWO)
     68 		ratio = 1 << ratio;
     69 	else
     70 		ratio++;
     71 
     72 	return rate / ratio;
     73 }
     74 
     75 int
     76 sunxi_ccu_div_set_rate(struct sunxi_ccu_softc *sc,
     77     struct sunxi_ccu_clk *clk, u_int new_rate)
     78 {
     79 	return EINVAL;
     80 }
     81 
     82 int
     83 sunxi_ccu_div_set_parent(struct sunxi_ccu_softc *sc,
     84     struct sunxi_ccu_clk *clk, const char *name)
     85 {
     86 	struct sunxi_ccu_div *div = &clk->u.div;
     87 	uint32_t val;
     88 	u_int index;
     89 
     90 	KASSERT(clk->type == SUNXI_CCU_DIV);
     91 
     92 	if (div->sel == 0)
     93 		return ENODEV;
     94 
     95 	for (index = 0; index < div->nparents; index++) {
     96 		if (div->parents[index] != NULL &&
     97 		    strcmp(div->parents[index], name) == 0)
     98 			break;
     99 	}
    100 	if (index == div->nparents)
    101 		return EINVAL;
    102 
    103 	val = CCU_READ(sc, div->reg);
    104 	val &= ~div->sel;
    105 	val |= __SHIFTIN(index, div->sel);
    106 	CCU_WRITE(sc, div->reg, val);
    107 
    108 	return 0;
    109 }
    110 
    111 const char *
    112 sunxi_ccu_div_get_parent(struct sunxi_ccu_softc *sc,
    113     struct sunxi_ccu_clk *clk)
    114 {
    115 	struct sunxi_ccu_div *div = &clk->u.div;
    116 	u_int index;
    117 	uint32_t val;
    118 
    119 	KASSERT(clk->type == SUNXI_CCU_DIV);
    120 
    121 	if (div->sel == 0)
    122 		return div->parents[0];
    123 
    124 	val = CCU_READ(sc, div->reg);
    125 	index = __SHIFTOUT(val, div->sel);
    126 
    127 	return div->parents[index];
    128 }
    129