imx_ccm_div.c revision 1.1.2.2
1 1.1.2.2 thorpej /* $NetBSD: imx_ccm_div.c,v 1.1.2.2 2021/01/03 16:34:52 thorpej Exp $ */ 2 1.1.2.2 thorpej 3 1.1.2.2 thorpej /*- 4 1.1.2.2 thorpej * Copyright (c) 2020 Jared McNeill <jmcneill (at) invisible.ca> 5 1.1.2.2 thorpej * All rights reserved. 6 1.1.2.2 thorpej * 7 1.1.2.2 thorpej * Redistribution and use in source and binary forms, with or without 8 1.1.2.2 thorpej * modification, are permitted provided that the following conditions 9 1.1.2.2 thorpej * are met: 10 1.1.2.2 thorpej * 1. Redistributions of source code must retain the above copyright 11 1.1.2.2 thorpej * notice, this list of conditions and the following disclaimer. 12 1.1.2.2 thorpej * 2. Redistributions in binary form must reproduce the above copyright 13 1.1.2.2 thorpej * notice, this list of conditions and the following disclaimer in the 14 1.1.2.2 thorpej * documentation and/or other materials provided with the distribution. 15 1.1.2.2 thorpej * 16 1.1.2.2 thorpej * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 1.1.2.2 thorpej * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 1.1.2.2 thorpej * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 1.1.2.2 thorpej * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 1.1.2.2 thorpej * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 1.1.2.2 thorpej * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 22 1.1.2.2 thorpej * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 1.1.2.2 thorpej * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 1.1.2.2 thorpej * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 1.1.2.2 thorpej * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 1.1.2.2 thorpej * SUCH DAMAGE. 27 1.1.2.2 thorpej */ 28 1.1.2.2 thorpej 29 1.1.2.2 thorpej #include <sys/cdefs.h> 30 1.1.2.2 thorpej __KERNEL_RCSID(0, "$NetBSD: imx_ccm_div.c,v 1.1.2.2 2021/01/03 16:34:52 thorpej Exp $"); 31 1.1.2.2 thorpej 32 1.1.2.2 thorpej #include <sys/param.h> 33 1.1.2.2 thorpej #include <sys/bus.h> 34 1.1.2.2 thorpej 35 1.1.2.2 thorpej #include <dev/clk/clk_backend.h> 36 1.1.2.2 thorpej 37 1.1.2.2 thorpej #include <arm/nxp/imx_ccm.h> 38 1.1.2.2 thorpej 39 1.1.2.2 thorpej #include <dev/fdt/fdtvar.h> 40 1.1.2.2 thorpej 41 1.1.2.2 thorpej u_int 42 1.1.2.2 thorpej imx_ccm_div_get_rate(struct imx_ccm_softc *sc, 43 1.1.2.2 thorpej struct imx_ccm_clk *clk) 44 1.1.2.2 thorpej { 45 1.1.2.2 thorpej struct imx_ccm_div *div = &clk->u.div; 46 1.1.2.2 thorpej struct clk *clkp, *clkp_parent; 47 1.1.2.2 thorpej 48 1.1.2.2 thorpej KASSERT(clk->type == IMX_CCM_DIV); 49 1.1.2.2 thorpej 50 1.1.2.2 thorpej clkp = &clk->base; 51 1.1.2.2 thorpej clkp_parent = clk_get_parent(clkp); 52 1.1.2.2 thorpej if (clkp_parent == NULL) 53 1.1.2.2 thorpej return 0; 54 1.1.2.2 thorpej 55 1.1.2.2 thorpej const u_int prate = clk_get_rate(clkp_parent); 56 1.1.2.2 thorpej if (prate == 0) 57 1.1.2.2 thorpej return 0; 58 1.1.2.2 thorpej 59 1.1.2.2 thorpej const uint32_t val = CCM_READ(sc, clk->regidx, div->reg); 60 1.1.2.2 thorpej const u_int n = __SHIFTOUT(val, div->mask); 61 1.1.2.2 thorpej 62 1.1.2.2 thorpej return prate / (n + 1); 63 1.1.2.2 thorpej } 64 1.1.2.2 thorpej 65 1.1.2.2 thorpej int 66 1.1.2.2 thorpej imx_ccm_div_set_rate(struct imx_ccm_softc *sc, 67 1.1.2.2 thorpej struct imx_ccm_clk *clk, u_int rate) 68 1.1.2.2 thorpej { 69 1.1.2.2 thorpej struct imx_ccm_div *div = &clk->u.div; 70 1.1.2.2 thorpej struct clk *clkp, *clkp_parent; 71 1.1.2.2 thorpej int best_diff = INT_MAX; 72 1.1.2.2 thorpej u_int n, best_n; 73 1.1.2.2 thorpej uint32_t val; 74 1.1.2.2 thorpej 75 1.1.2.2 thorpej KASSERT(clk->type == IMX_CCM_DIV); 76 1.1.2.2 thorpej 77 1.1.2.2 thorpej clkp = &clk->base; 78 1.1.2.2 thorpej clkp_parent = clk_get_parent(clkp); 79 1.1.2.2 thorpej if (clkp_parent == NULL) 80 1.1.2.2 thorpej return ENXIO; 81 1.1.2.2 thorpej 82 1.1.2.2 thorpej if ((div->flags & IMX_DIV_SET_RATE_PARENT) != 0) 83 1.1.2.2 thorpej return clk_set_rate(clkp, rate); 84 1.1.2.2 thorpej 85 1.1.2.2 thorpej const u_int prate = clk_get_rate(clkp_parent); 86 1.1.2.2 thorpej if (prate == 0) 87 1.1.2.2 thorpej return EIO; 88 1.1.2.2 thorpej 89 1.1.2.2 thorpej for (n = 0; n < __SHIFTOUT_MASK(div->mask); n++) { 90 1.1.2.2 thorpej const u_int tmp_rate = prate / (n + 1); 91 1.1.2.2 thorpej const int diff = (int)rate - (int)tmp_rate; 92 1.1.2.2 thorpej if ((div->flags & IMX_DIV_ROUND_DOWN) != 0) { 93 1.1.2.2 thorpej if (diff >= 0 && diff < best_diff) { 94 1.1.2.2 thorpej best_n = n; 95 1.1.2.2 thorpej best_diff = diff; 96 1.1.2.2 thorpej } 97 1.1.2.2 thorpej } else { 98 1.1.2.2 thorpej if (abs(diff) < abs(best_diff)) { 99 1.1.2.2 thorpej best_n = n; 100 1.1.2.2 thorpej best_diff = abs(diff); 101 1.1.2.2 thorpej } 102 1.1.2.2 thorpej } 103 1.1.2.2 thorpej } 104 1.1.2.2 thorpej if (best_diff == INT_MAX) 105 1.1.2.2 thorpej return EIO; 106 1.1.2.2 thorpej 107 1.1.2.2 thorpej val = CCM_READ(sc, clk->regidx, div->reg); 108 1.1.2.2 thorpej val &= ~div->mask; 109 1.1.2.2 thorpej val |= __SHIFTIN(best_n, div->mask); 110 1.1.2.2 thorpej CCM_WRITE(sc, clk->regidx, div->reg, val); 111 1.1.2.2 thorpej 112 1.1.2.2 thorpej return 0; 113 1.1.2.2 thorpej } 114 1.1.2.2 thorpej 115 1.1.2.2 thorpej const char * 116 1.1.2.2 thorpej imx_ccm_div_get_parent(struct imx_ccm_softc *sc, 117 1.1.2.2 thorpej struct imx_ccm_clk *clk) 118 1.1.2.2 thorpej { 119 1.1.2.2 thorpej struct imx_ccm_div *div = &clk->u.div; 120 1.1.2.2 thorpej 121 1.1.2.2 thorpej KASSERT(clk->type == IMX_CCM_DIV); 122 1.1.2.2 thorpej 123 1.1.2.2 thorpej return div->parent; 124 1.1.2.2 thorpej } 125
Indexes created Tue Sep 30 17:09:57 GMT 2025