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rk_cru_composite.c revision 1.5.14.1 
      1 /* $NetBSD: rk_cru_composite.c,v 1.5.14.1 2021/05/31 22:15:11 cjep Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2018 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: rk_cru_composite.c,v 1.5.14.1 2021/05/31 22:15:11 cjep Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/bus.h>
     34 
     35 #include <dev/clk/clk_backend.h>
     36 
     37 #include <arm/rockchip/rk_cru.h>
     38 
     39 #include <dev/fdt/fdtvar.h>
     40 
     41 int
     42 rk_cru_composite_enable(struct rk_cru_softc *sc, struct rk_cru_clk *clk,
     43     int enable)
     44 {
     45 	struct rk_cru_composite *composite = &clk->u.composite;
     46 
     47 	KASSERT(clk->type == RK_CRU_COMPOSITE);
     48 
     49 	if (composite->gate_mask == 0)
     50 		return enable ? 0 : ENXIO;
     51 
     52 	const uint32_t write_mask = composite->gate_mask << 16;
     53 	const uint32_t write_val = enable ? 0 : composite->gate_mask;
     54 
     55 	CRU_WRITE(sc, composite->gate_reg, write_mask | write_val);
     56 
     57 	return 0;
     58 }
     59 
     60 u_int
     61 rk_cru_composite_get_rate(struct rk_cru_softc *sc,
     62     struct rk_cru_clk *clk)
     63 {
     64 	struct rk_cru_composite *composite = &clk->u.composite;
     65 	struct clk *clkp, *clkp_parent;
     66 
     67 	KASSERT(clk->type == RK_CRU_COMPOSITE);
     68 
     69 	clkp = &clk->base;
     70 	clkp_parent = clk_get_parent(clkp);
     71 	if (clkp_parent == NULL)
     72 		return 0;
     73 
     74 	const u_int prate = clk_get_rate(clkp_parent);
     75 	if (prate == 0)
     76 		return 0;
     77 
     78 	if (composite->flags & RK_COMPOSITE_FRACDIV) {
     79 		const uint32_t val = CRU_READ(sc, composite->frac_reg);
     80 		const u_int num = (val >> 16) & 0xffff;
     81 		const u_int den = val & 0xffff;
     82 
     83 		return (u_int)((uint64_t)prate * num / den);
     84 	} else {
     85 		const uint32_t val = CRU_READ(sc, composite->muxdiv_reg);
     86 		const u_int div = (composite->div_mask != 0)
     87 		    ? __SHIFTOUT(val, composite->div_mask) + 1 : 1;
     88 
     89 		return prate / div;
     90 	}
     91 }
     92 
     93 static u_int
     94 rk_cru_composite_get_frac_div(u_int n, u_int d)
     95 {
     96 	u_int tmp;
     97 
     98 	while (d > 0) {
     99 		tmp = d;
    100 		d = n % d;
    101 		n = tmp;
    102 	}
    103 
    104 	return n;
    105 }
    106 
    107 static int
    108 rk_cru_composite_set_rate_frac(struct rk_cru_softc *sc,
    109     struct rk_cru_clk *clk, u_int rate)
    110 {
    111 	struct rk_cru_composite *composite = &clk->u.composite;
    112 	struct clk *clk_parent;
    113 
    114 	clk_parent = clk_get_parent(&clk->base);
    115 	if (clk_parent == NULL)
    116 		return ENXIO;
    117 
    118 	const u_int prate = clk_get_rate(clk_parent);
    119 	const u_int v = rk_cru_composite_get_frac_div(prate, rate);
    120 	const u_int num = (prate / v) & 0xffff;
    121 	const u_int den = (rate / v) & 0xffff;
    122 	if (prate / num * den != rate)
    123 		return EINVAL;
    124 
    125 	CRU_WRITE(sc, composite->frac_reg, (den << 16) | num);
    126 
    127 	return 0;
    128 }
    129 
    130 int
    131 rk_cru_composite_set_rate(struct rk_cru_softc *sc,
    132     struct rk_cru_clk *clk, u_int rate)
    133 {
    134 	struct rk_cru_composite *composite = &clk->u.composite;
    135 	u_int best_div, best_mux, best_diff;
    136 	struct rk_cru_clk *rclk_parent;
    137 	struct clk *clk_parent;
    138 
    139 	KASSERT(clk->type == RK_CRU_COMPOSITE);
    140 
    141 	if (composite->flags & RK_COMPOSITE_SET_RATE_PARENT) {
    142 		clk_parent = clk_get_parent(&clk->base);
    143 		if (clk_parent == NULL)
    144 			return ENXIO;
    145 		return clk_set_rate(clk_parent, rate);
    146 	}
    147 
    148 	if (composite->flags & RK_COMPOSITE_FRACDIV) {
    149 		return rk_cru_composite_set_rate_frac(sc, clk, rate);
    150 	}
    151 
    152 	best_div = 0;
    153 	best_mux = 0;
    154 	best_diff = INT_MAX;
    155 	for (u_int mux = 0; mux < composite->nparents; mux++) {
    156 		rclk_parent = rk_cru_clock_find(sc, composite->parents[mux]);
    157 		if (rclk_parent != NULL)
    158 			clk_parent = &rclk_parent->base;
    159 		else
    160 			clk_parent = fdtbus_clock_byname(composite->parents[mux]);
    161 		if (clk_parent == NULL)
    162 			continue;
    163 
    164 		const u_int prate = clk_get_rate(clk_parent);
    165 		if (prate == 0)
    166 			continue;
    167 
    168 		for (u_int div = 1; div <= __SHIFTOUT_MASK(composite->div_mask) + 1; div++) {
    169 			const u_int cur_rate = prate / div;
    170 			const int diff = (int)rate - (int)cur_rate;
    171 			if (composite->flags & RK_COMPOSITE_ROUND_DOWN) {
    172 				if (diff >= 0 && diff < best_diff) {
    173 					best_diff = diff;
    174 					best_mux = mux;
    175 					best_div = div;
    176 				}
    177 			} else {
    178 				if (abs(diff) < best_diff) {
    179 					best_diff = abs(diff);
    180 					best_mux = mux;
    181 					best_div = div;
    182 				}
    183 			}
    184 		}
    185 	}
    186 	if (best_diff == INT_MAX)
    187 		return ERANGE;
    188 
    189 	uint32_t write_mask = composite->div_mask << 16;
    190 	uint32_t write_val = __SHIFTIN(best_div - 1, composite->div_mask);
    191 	if (composite->mux_mask) {
    192 		write_mask |= composite->mux_mask << 16;
    193 		write_val |= __SHIFTIN(best_mux, composite->mux_mask);
    194 	}
    195 
    196 	CRU_WRITE(sc, composite->muxdiv_reg, write_mask | write_val);
    197 
    198 	return 0;
    199 }
    200 
    201 const char *
    202 rk_cru_composite_get_parent(struct rk_cru_softc *sc,
    203     struct rk_cru_clk *clk)
    204 {
    205 	struct rk_cru_composite *composite = &clk->u.composite;
    206 	uint32_t val;
    207 	u_int mux;
    208 
    209 	KASSERT(clk->type == RK_CRU_COMPOSITE);
    210 
    211 	if (composite->mux_mask) {
    212 		val = CRU_READ(sc, composite->muxdiv_reg);
    213 		mux = __SHIFTOUT(val, composite->mux_mask);
    214 	} else {
    215 		mux = 0;
    216 	}
    217 
    218 	return composite->parents[mux];
    219 }
    220 
    221 int
    222 rk_cru_composite_set_parent(struct rk_cru_softc *sc,
    223     struct rk_cru_clk *clk, const char *parent)
    224 {
    225 	struct rk_cru_composite *composite = &clk->u.composite;
    226 
    227 	KASSERT(clk->type == RK_CRU_COMPOSITE);
    228 
    229 	if (!composite->mux_mask)
    230 		return EINVAL;
    231 
    232 	for (u_int mux = 0; mux < composite->nparents; mux++) {
    233 		if (strcmp(composite->parents[mux], parent) == 0) {
    234 			const uint32_t write_mask = composite->mux_mask << 16;
    235 			const uint32_t write_val = __SHIFTIN(mux, composite->mux_mask);
    236 
    237 			CRU_WRITE(sc, composite->muxdiv_reg, write_mask | write_val);
    238 			return 0;
    239 		}
    240 	}
    241 
    242 	return EINVAL;
    243 }
    244