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rk_cru_composite.c revision 1.3.4.1 
      1 /* $NetBSD: rk_cru_composite.c,v 1.3.4.1 2020/04/13 08:03:37 martin 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 1.3.4.1 2020/04/13 08:03:37 martin 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 = __SHIFTOUT(val, composite->div_mask) + 1;
     87 
     88 		return prate / div;
     89 	}
     90 }
     91 
     92 static u_int
     93 rk_cru_composite_get_frac_div(u_int n, u_int d)
     94 {
     95 	u_int tmp;
     96 
     97 	while (d > 0) {
     98 		tmp = d;
     99 		d = n % d;
    100 		n = tmp;
    101 	}
    102 
    103 	return n;
    104 }
    105 
    106 static int
    107 rk_cru_composite_set_rate_frac(struct rk_cru_softc *sc,
    108     struct rk_cru_clk *clk, u_int rate)
    109 {
    110 	struct rk_cru_composite *composite = &clk->u.composite;
    111 	struct clk *clk_parent;
    112 
    113 	clk_parent = clk_get_parent(&clk->base);
    114 	if (clk_parent == NULL)
    115 		return ENXIO;
    116 
    117 	const u_int prate = clk_get_rate(clk_parent);
    118 	const u_int v = rk_cru_composite_get_frac_div(prate, rate);
    119 	const u_int num = (prate / v) & 0xffff;
    120 	const u_int den = (rate / v) & 0xffff;
    121 	if (prate / num * den != rate)
    122 		return EINVAL;
    123 
    124 	CRU_WRITE(sc, composite->frac_reg, (den << 16) | num);
    125 
    126 	return 0;
    127 }
    128 
    129 int
    130 rk_cru_composite_set_rate(struct rk_cru_softc *sc,
    131     struct rk_cru_clk *clk, u_int rate)
    132 {
    133 	struct rk_cru_composite *composite = &clk->u.composite;
    134 	u_int best_div, best_mux, best_diff;
    135 	struct rk_cru_clk *rclk_parent;
    136 	struct clk *clk_parent;
    137 
    138 	KASSERT(clk->type == RK_CRU_COMPOSITE);
    139 
    140 	if (composite->flags & RK_COMPOSITE_SET_RATE_PARENT) {
    141 		clk_parent = clk_get_parent(&clk->base);
    142 		if (clk_parent == NULL)
    143 			return ENXIO;
    144 		return clk_set_rate(clk_parent, rate);
    145 	}
    146 
    147 	if (composite->flags & RK_COMPOSITE_FRACDIV) {
    148 		return rk_cru_composite_set_rate_frac(sc, clk, rate);
    149 	}
    150 
    151 	best_div = 0;
    152 	best_mux = 0;
    153 	best_diff = INT_MAX;
    154 	for (u_int mux = 0; mux < composite->nparents; mux++) {
    155 		rclk_parent = rk_cru_clock_find(sc, composite->parents[mux]);
    156 		if (rclk_parent != NULL)
    157 			clk_parent = &rclk_parent->base;
    158 		else
    159 			clk_parent = fdtbus_clock_byname(composite->parents[mux]);
    160 		if (clk_parent == NULL)
    161 			continue;
    162 
    163 		const u_int prate = clk_get_rate(clk_parent);
    164 		if (prate == 0)
    165 			continue;
    166 
    167 		for (u_int div = 1; div <= __SHIFTOUT_MASK(composite->div_mask) + 1; div++) {
    168 			const u_int cur_rate = prate / div;
    169 			const int diff = (int)rate - (int)cur_rate;
    170 			if (composite->flags & RK_COMPOSITE_ROUND_DOWN) {
    171 				if (diff >= 0 && diff < best_diff) {
    172 					best_diff = diff;
    173 					best_mux = mux;
    174 					best_div = div;
    175 				}
    176 			} else {
    177 				if (abs(diff) < best_diff) {
    178 					best_diff = abs(diff);
    179 					best_mux = mux;
    180 					best_div = div;
    181 				}
    182 			}
    183 		}
    184 	}
    185 	if (best_diff == INT_MAX)
    186 		return ERANGE;
    187 
    188 	uint32_t write_mask = composite->div_mask << 16;
    189 	uint32_t write_val = __SHIFTIN(best_div - 1, composite->div_mask);
    190 	if (composite->mux_mask) {
    191 		write_mask |= composite->mux_mask << 16;
    192 		write_val |= __SHIFTIN(best_mux, composite->mux_mask);
    193 	}
    194 
    195 	CRU_WRITE(sc, composite->muxdiv_reg, write_mask | write_val);
    196 
    197 	return 0;
    198 }
    199 
    200 const char *
    201 rk_cru_composite_get_parent(struct rk_cru_softc *sc,
    202     struct rk_cru_clk *clk)
    203 {
    204 	struct rk_cru_composite *composite = &clk->u.composite;
    205 	uint32_t val;
    206 	u_int mux;
    207 
    208 	KASSERT(clk->type == RK_CRU_COMPOSITE);
    209 
    210 	if (composite->mux_mask) {
    211 		val = CRU_READ(sc, composite->muxdiv_reg);
    212 		mux = __SHIFTOUT(val, composite->mux_mask);
    213 	} else {
    214 		mux = 0;
    215 	}
    216 
    217 	return composite->parents[mux];
    218 }
    219 
    220 int
    221 rk_cru_composite_set_parent(struct rk_cru_softc *sc,
    222     struct rk_cru_clk *clk, const char *parent)
    223 {
    224 	struct rk_cru_composite *composite = &clk->u.composite;
    225 
    226 	KASSERT(clk->type == RK_CRU_COMPOSITE);
    227 
    228 	if (!composite->mux_mask)
    229 		return EINVAL;
    230 
    231 	for (u_int mux = 0; mux < composite->nparents; mux++) {
    232 		if (strcmp(composite->parents[mux], parent) == 0) {
    233 			const uint32_t write_mask = composite->mux_mask << 16;
    234 			const uint32_t write_val = __SHIFTIN(mux, composite->mux_mask);
    235 
    236 			CRU_WRITE(sc, composite->muxdiv_reg, write_mask | write_val);
    237 			return 0;
    238 		}
    239 	}
    240 
    241 	return EINVAL;
    242 }
    243