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sunxi_ccu_prediv.c revision 1.2.4.2
      1  1.2.4.2  snj /* $NetBSD: sunxi_ccu_prediv.c,v 1.2.4.2 2017/07/18 19:13:08 snj Exp $ */
      2  1.2.4.2  snj 
      3  1.2.4.2  snj /*-
      4  1.2.4.2  snj  * Copyright (c) 2017 Jared McNeill <jmcneill (at) invisible.ca>
      5  1.2.4.2  snj  * All rights reserved.
      6  1.2.4.2  snj  *
      7  1.2.4.2  snj  * Redistribution and use in source and binary forms, with or without
      8  1.2.4.2  snj  * modification, are permitted provided that the following conditions
      9  1.2.4.2  snj  * are met:
     10  1.2.4.2  snj  * 1. Redistributions of source code must retain the above copyright
     11  1.2.4.2  snj  *    notice, this list of conditions and the following disclaimer.
     12  1.2.4.2  snj  * 2. Redistributions in binary form must reproduce the above copyright
     13  1.2.4.2  snj  *    notice, this list of conditions and the following disclaimer in the
     14  1.2.4.2  snj  *    documentation and/or other materials provided with the distribution.
     15  1.2.4.2  snj  *
     16  1.2.4.2  snj  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  1.2.4.2  snj  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  1.2.4.2  snj  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  1.2.4.2  snj  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  1.2.4.2  snj  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  1.2.4.2  snj  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22  1.2.4.2  snj  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  1.2.4.2  snj  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  1.2.4.2  snj  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  1.2.4.2  snj  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  1.2.4.2  snj  * SUCH DAMAGE.
     27  1.2.4.2  snj  */
     28  1.2.4.2  snj 
     29  1.2.4.2  snj #include <sys/cdefs.h>
     30  1.2.4.2  snj __KERNEL_RCSID(0, "$NetBSD: sunxi_ccu_prediv.c,v 1.2.4.2 2017/07/18 19:13:08 snj Exp $");
     31  1.2.4.2  snj 
     32  1.2.4.2  snj #include <sys/param.h>
     33  1.2.4.2  snj #include <sys/bus.h>
     34  1.2.4.2  snj 
     35  1.2.4.2  snj #include <dev/clk/clk_backend.h>
     36  1.2.4.2  snj 
     37  1.2.4.2  snj #include <arm/sunxi/sunxi_ccu.h>
     38  1.2.4.2  snj 
     39  1.2.4.2  snj u_int
     40  1.2.4.2  snj sunxi_ccu_prediv_get_rate(struct sunxi_ccu_softc *sc,
     41  1.2.4.2  snj     struct sunxi_ccu_clk *clk)
     42  1.2.4.2  snj {
     43  1.2.4.2  snj 	struct sunxi_ccu_prediv *prediv = &clk->u.prediv;
     44  1.2.4.2  snj 	struct clk *clkp, *clkp_parent;
     45  1.2.4.2  snj 	u_int rate, pre, div, sel;
     46  1.2.4.2  snj 	uint32_t val;
     47  1.2.4.2  snj 
     48  1.2.4.2  snj 	KASSERT(clk->type == SUNXI_CCU_PREDIV);
     49  1.2.4.2  snj 
     50  1.2.4.2  snj 	clkp = &clk->base;
     51  1.2.4.2  snj 	clkp_parent = clk_get_parent(clkp);
     52  1.2.4.2  snj 	if (clkp_parent == NULL)
     53  1.2.4.2  snj 		return 0;
     54  1.2.4.2  snj 
     55  1.2.4.2  snj 	rate = clk_get_rate(clkp_parent);
     56  1.2.4.2  snj 	if (rate == 0)
     57  1.2.4.2  snj 		return 0;
     58  1.2.4.2  snj 
     59  1.2.4.2  snj 	val = CCU_READ(sc, prediv->reg);
     60  1.2.4.2  snj 	if (prediv->prediv)
     61  1.2.4.2  snj 		pre = __SHIFTOUT(val, prediv->prediv);
     62  1.2.4.2  snj 	else
     63  1.2.4.2  snj 		pre = 0;
     64  1.2.4.2  snj 	if (prediv->div)
     65  1.2.4.2  snj 		div = __SHIFTOUT(val, prediv->div);
     66  1.2.4.2  snj 	else
     67  1.2.4.2  snj 		div = 0;
     68  1.2.4.2  snj 	sel = __SHIFTOUT(val, prediv->sel);
     69  1.2.4.2  snj 
     70  1.2.4.2  snj 	if (prediv->flags & SUNXI_CCU_PREDIV_POWER_OF_TWO)
     71  1.2.4.2  snj 		div = 1 << div;
     72  1.2.4.2  snj 	else
     73  1.2.4.2  snj 		div++;
     74  1.2.4.2  snj 
     75  1.2.4.2  snj 	pre++;
     76  1.2.4.2  snj 
     77  1.2.4.2  snj 	if (prediv->flags & SUNXI_CCU_PREDIV_DIVIDE_BY_TWO)
     78  1.2.4.2  snj 		pre *= 2;
     79  1.2.4.2  snj 
     80  1.2.4.2  snj 	if (prediv->prediv_sel & __BIT(sel))
     81  1.2.4.2  snj 		return rate / pre / div;
     82  1.2.4.2  snj 	else
     83  1.2.4.2  snj 		return rate / div;
     84  1.2.4.2  snj }
     85  1.2.4.2  snj 
     86  1.2.4.2  snj int
     87  1.2.4.2  snj sunxi_ccu_prediv_set_rate(struct sunxi_ccu_softc *sc,
     88  1.2.4.2  snj     struct sunxi_ccu_clk *clk, u_int new_rate)
     89  1.2.4.2  snj {
     90  1.2.4.2  snj 	return EINVAL;
     91  1.2.4.2  snj }
     92  1.2.4.2  snj 
     93  1.2.4.2  snj int
     94  1.2.4.2  snj sunxi_ccu_prediv_set_parent(struct sunxi_ccu_softc *sc,
     95  1.2.4.2  snj     struct sunxi_ccu_clk *clk, const char *name)
     96  1.2.4.2  snj {
     97  1.2.4.2  snj 	struct sunxi_ccu_prediv *prediv = &clk->u.prediv;
     98  1.2.4.2  snj 	uint32_t val;
     99  1.2.4.2  snj 	u_int index;
    100  1.2.4.2  snj 
    101  1.2.4.2  snj 	KASSERT(clk->type == SUNXI_CCU_PREDIV);
    102  1.2.4.2  snj 
    103  1.2.4.2  snj 	if (prediv->sel == 0)
    104  1.2.4.2  snj 		return ENODEV;
    105  1.2.4.2  snj 
    106  1.2.4.2  snj 	for (index = 0; index < prediv->nparents; index++) {
    107  1.2.4.2  snj 		if (prediv->parents[index] != NULL &&
    108  1.2.4.2  snj 		    strcmp(prediv->parents[index], name) == 0)
    109  1.2.4.2  snj 			break;
    110  1.2.4.2  snj 	}
    111  1.2.4.2  snj 	if (index == prediv->nparents)
    112  1.2.4.2  snj 		return EINVAL;
    113  1.2.4.2  snj 
    114  1.2.4.2  snj 	val = CCU_READ(sc, prediv->reg);
    115  1.2.4.2  snj 	val &= ~prediv->sel;
    116  1.2.4.2  snj 	val |= __SHIFTIN(index, prediv->sel);
    117  1.2.4.2  snj 	CCU_WRITE(sc, prediv->reg, val);
    118  1.2.4.2  snj 
    119  1.2.4.2  snj 	return 0;
    120  1.2.4.2  snj }
    121  1.2.4.2  snj 
    122  1.2.4.2  snj const char *
    123  1.2.4.2  snj sunxi_ccu_prediv_get_parent(struct sunxi_ccu_softc *sc,
    124  1.2.4.2  snj     struct sunxi_ccu_clk *clk)
    125  1.2.4.2  snj {
    126  1.2.4.2  snj 	struct sunxi_ccu_prediv *prediv = &clk->u.prediv;
    127  1.2.4.2  snj 	u_int index;
    128  1.2.4.2  snj 	uint32_t val;
    129  1.2.4.2  snj 
    130  1.2.4.2  snj 	KASSERT(clk->type == SUNXI_CCU_PREDIV);
    131  1.2.4.2  snj 
    132  1.2.4.2  snj 	val = CCU_READ(sc, prediv->reg);
    133  1.2.4.2  snj 	index = __SHIFTOUT(val, prediv->sel);
    134  1.2.4.2  snj 
    135  1.2.4.2  snj 	return prediv->parents[index];
    136  1.2.4.2  snj }
    137