1 /* 2 * This file is provided under a dual BSD/GPLv2 license. When using or 3 * redistributing this file, you may do so under either license. 4 * 5 * GPL LICENSE SUMMARY 6 * 7 * Copyright (c) 2016 AmLogic, Inc. 8 * Author: Michael Turquette <mturquette@baylibre.com> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of version 2 of the GNU General Public License as 12 * published by the Free Software Foundation. 13 * 14 * This program is distributed in the hope that it will be useful, but 15 * WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. 22 * The full GNU General Public License is included in this distribution 23 * in the file called COPYING 24 * 25 * BSD LICENSE 26 * 27 * Copyright (c) 2016 AmLogic, Inc. 28 * Author: Michael Turquette <mturquette@baylibre.com> 29 * 30 * Redistribution and use in source and binary forms, with or without 31 * modification, are permitted provided that the following conditions 32 * are met: 33 * 34 * * Redistributions of source code must retain the above copyright 35 * notice, this list of conditions and the following disclaimer. 36 * * Redistributions in binary form must reproduce the above copyright 37 * notice, this list of conditions and the following disclaimer in 38 * the documentation and/or other materials provided with the 39 * distribution. 40 * * Neither the name of Intel Corporation nor the names of its 41 * contributors may be used to endorse or promote products derived 42 * from this software without specific prior written permission. 43 * 44 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 45 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 46 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 47 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 48 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 49 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 50 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 51 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 52 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 53 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 54 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 55 */ 56 57 /* 58 * MultiPhase Locked Loops are outputs from a PLL with additional frequency 59 * scaling capabilities. MPLL rates are calculated as: 60 * 61 * f(N2_integer, SDM_IN ) = 2.0G/(N2_integer + SDM_IN/16384) 62 */ 63 64 #include <linux/clk-provider.h> 65 #include "clkc.h" 66 67 #define SDM_DEN 16384 68 #define N2_MIN 4 69 #define N2_MAX 511 70 71 #define to_meson_clk_mpll(_hw) container_of(_hw, struct meson_clk_mpll, hw) 72 73 static long rate_from_params(unsigned long parent_rate, 74 unsigned long sdm, 75 unsigned long n2) 76 { 77 unsigned long divisor = (SDM_DEN * n2) + sdm; 78 79 if (n2 < N2_MIN) 80 return -EINVAL; 81 82 return DIV_ROUND_UP_ULL((u64)parent_rate * SDM_DEN, divisor); 83 } 84 85 static void params_from_rate(unsigned long requested_rate, 86 unsigned long parent_rate, 87 unsigned long *sdm, 88 unsigned long *n2) 89 { 90 uint64_t div = parent_rate; 91 unsigned long rem = do_div(div, requested_rate); 92 93 if (div < N2_MIN) { 94 *n2 = N2_MIN; 95 *sdm = 0; 96 } else if (div > N2_MAX) { 97 *n2 = N2_MAX; 98 *sdm = SDM_DEN - 1; 99 } else { 100 *n2 = div; 101 *sdm = DIV_ROUND_UP(rem * SDM_DEN, requested_rate); 102 } 103 } 104 105 static unsigned long mpll_recalc_rate(struct clk_hw *hw, 106 unsigned long parent_rate) 107 { 108 struct meson_clk_mpll *mpll = to_meson_clk_mpll(hw); 109 struct parm *p; 110 unsigned long reg, sdm, n2; 111 long rate; 112 113 p = &mpll->sdm; 114 reg = readl(mpll->base + p->reg_off); 115 sdm = PARM_GET(p->width, p->shift, reg); 116 117 p = &mpll->n2; 118 reg = readl(mpll->base + p->reg_off); 119 n2 = PARM_GET(p->width, p->shift, reg); 120 121 rate = rate_from_params(parent_rate, sdm, n2); 122 if (rate < 0) 123 return 0; 124 125 return rate; 126 } 127 128 static long mpll_round_rate(struct clk_hw *hw, 129 unsigned long rate, 130 unsigned long *parent_rate) 131 { 132 unsigned long sdm, n2; 133 134 params_from_rate(rate, *parent_rate, &sdm, &n2); 135 return rate_from_params(*parent_rate, sdm, n2); 136 } 137 138 static int mpll_set_rate(struct clk_hw *hw, 139 unsigned long rate, 140 unsigned long parent_rate) 141 { 142 struct meson_clk_mpll *mpll = to_meson_clk_mpll(hw); 143 struct parm *p; 144 unsigned long reg, sdm, n2; 145 unsigned long flags = 0; 146 147 params_from_rate(rate, parent_rate, &sdm, &n2); 148 149 if (mpll->lock) 150 spin_lock_irqsave(mpll->lock, flags); 151 else 152 __acquire(mpll->lock); 153 154 p = &mpll->sdm; 155 reg = readl(mpll->base + p->reg_off); 156 reg = PARM_SET(p->width, p->shift, reg, sdm); 157 writel(reg, mpll->base + p->reg_off); 158 159 p = &mpll->sdm_en; 160 reg = readl(mpll->base + p->reg_off); 161 reg = PARM_SET(p->width, p->shift, reg, 1); 162 writel(reg, mpll->base + p->reg_off); 163 164 p = &mpll->n2; 165 reg = readl(mpll->base + p->reg_off); 166 reg = PARM_SET(p->width, p->shift, reg, n2); 167 writel(reg, mpll->base + p->reg_off); 168 169 if (mpll->lock) 170 spin_unlock_irqrestore(mpll->lock, flags); 171 else 172 __release(mpll->lock); 173 174 return 0; 175 } 176 177 static void mpll_enable_core(struct clk_hw *hw, int enable) 178 { 179 struct meson_clk_mpll *mpll = to_meson_clk_mpll(hw); 180 struct parm *p; 181 unsigned long reg; 182 unsigned long flags = 0; 183 184 if (mpll->lock) 185 spin_lock_irqsave(mpll->lock, flags); 186 else 187 __acquire(mpll->lock); 188 189 p = &mpll->en; 190 reg = readl(mpll->base + p->reg_off); 191 reg = PARM_SET(p->width, p->shift, reg, enable ? 1 : 0); 192 writel(reg, mpll->base + p->reg_off); 193 194 if (mpll->lock) 195 spin_unlock_irqrestore(mpll->lock, flags); 196 else 197 __release(mpll->lock); 198 } 199 200 201 static int mpll_enable(struct clk_hw *hw) 202 { 203 mpll_enable_core(hw, 1); 204 205 return 0; 206 } 207 208 static void mpll_disable(struct clk_hw *hw) 209 { 210 mpll_enable_core(hw, 0); 211 } 212 213 static int mpll_is_enabled(struct clk_hw *hw) 214 { 215 struct meson_clk_mpll *mpll = to_meson_clk_mpll(hw); 216 struct parm *p; 217 unsigned long reg; 218 int en; 219 220 p = &mpll->en; 221 reg = readl(mpll->base + p->reg_off); 222 en = PARM_GET(p->width, p->shift, reg); 223 224 return en; 225 } 226 227 const struct clk_ops meson_clk_mpll_ro_ops = { 228 .recalc_rate = mpll_recalc_rate, 229 .round_rate = mpll_round_rate, 230 .is_enabled = mpll_is_enabled, 231 }; 232 233 const struct clk_ops meson_clk_mpll_ops = { 234 .recalc_rate = mpll_recalc_rate, 235 .round_rate = mpll_round_rate, 236 .set_rate = mpll_set_rate, 237 .enable = mpll_enable, 238 .disable = mpll_disable, 239 .is_enabled = mpll_is_enabled, 240 }; 241