drivers/clk/sunxi-ng/ccu_nkm.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2016 Maxime Ripard
   4  * Maxime Ripard <maxime.ripard@free-electrons.com>
   5  */
   6
   7 #include <linux/clk-provider.h>
   8 #include <linux/io.h>
   9
  10 #include "ccu_gate.h"
  11 #include "ccu_nkm.h"
  12
  13 struct _ccu_nkm {
  14         unsigned long   n, min_n, max_n;
  15         unsigned long   k, min_k, max_k;
  16         unsigned long   m, min_m, max_m;
  17 };
  18
  19 static bool ccu_nkm_is_valid_rate(struct ccu_common *common, unsigned long parent,
  20                                   unsigned long n, unsigned long m)
  21 {
  22         struct ccu_nkm *nkm = container_of(common, struct ccu_nkm, common);
  23
  24         if (nkm->max_m_n_ratio && (m > nkm->max_m_n_ratio * n))
  25                 return false;
  26
  27         if (nkm->min_parent_m_ratio && (parent < nkm->min_parent_m_ratio * m))
  28                 return false;
  29
  30         return true;
  31 }
  32
  33 static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common,
  34                                                        struct clk_hw *parent_hw,
  35                                                        unsigned long *parent, unsigned long rate,
  36                                                        struct _ccu_nkm *nkm)
  37 {
  38         unsigned long best_rate = 0, best_parent_rate = *parent;
  39         unsigned long best_n = 0, best_k = 0, best_m = 0;
  40         unsigned long _n, _k, _m;
  41
  42         for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
  43                 for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
  44                         for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
  45                                 unsigned long tmp_rate, tmp_parent;
  46
  47                                 tmp_parent = clk_hw_round_rate(parent_hw, rate * _m / (_n * _k));
  48
  49                                 if (!ccu_nkm_is_valid_rate(common, tmp_parent, _n, _m))
  50                                         continue;
  51
  52                                 tmp_rate = tmp_parent * _n * _k / _m;
  53
  54                                 if (ccu_is_better_rate(common, rate, tmp_rate, best_rate) ||
  55                                     (tmp_parent == *parent && tmp_rate == best_rate)) {
  56                                         best_rate = tmp_rate;
  57                                         best_parent_rate = tmp_parent;
  58                                         best_n = _n;
  59                                         best_k = _k;
  60                                         best_m = _m;
  61                                 }
  62                         }
  63                 }
  64         }
  65
  66         nkm->n = best_n;
  67         nkm->k = best_k;
  68         nkm->m = best_m;
  69
  70         *parent = best_parent_rate;
  71
  72         return best_rate;
  73 }
  74
  75 static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
  76                                        struct _ccu_nkm *nkm, struct ccu_common *common)
  77 {
  78         unsigned long best_rate = 0;
  79         unsigned long best_n = 0, best_k = 0, best_m = 0;
  80         unsigned long _n, _k, _m;
  81
  82         for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
  83                 for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
  84                         for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
  85                                 if (!ccu_nkm_is_valid_rate(common, parent, _n, _m))
  86                                         continue;
  87
  88                                 unsigned long tmp_rate;
  89
  90                                 tmp_rate = parent * _n * _k / _m;
  91
  92                                 if (ccu_is_better_rate(common, rate, tmp_rate, best_rate)) {
  93                                         best_rate = tmp_rate;
  94                                         best_n = _n;
  95                                         best_k = _k;
  96                                         best_m = _m;
  97                                 }
  98                         }
  99                 }
 100         }
 101
 102         nkm->n = best_n;
 103         nkm->k = best_k;
 104         nkm->m = best_m;
 105
 106         return best_rate;
 107 }
 108
 109 static void ccu_nkm_disable(struct clk_hw *hw)
 110 {
 111         struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
 112
 113         return ccu_gate_helper_disable(&nkm->common, nkm->enable);
 114 }
 115
 116 static int ccu_nkm_enable(struct clk_hw *hw)
 117 {
 118         struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
 119
 120         return ccu_gate_helper_enable(&nkm->common, nkm->enable);
 121 }
 122
 123 static int ccu_nkm_is_enabled(struct clk_hw *hw)
 124 {
 125         struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
 126
 127         return ccu_gate_helper_is_enabled(&nkm->common, nkm->enable);
 128 }
 129
 130 static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw,
 131                                         unsigned long parent_rate)
 132 {
 133         struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
 134         unsigned long n, m, k, rate;
 135         u32 reg;
 136
 137         reg = readl(nkm->common.base + nkm->common.reg);
 138
 139         n = reg >> nkm->n.shift;
 140         n &= (1 << nkm->n.width) - 1;
 141         n += nkm->n.offset;
 142         if (!n)
 143                 n++;
 144
 145         k = reg >> nkm->k.shift;
 146         k &= (1 << nkm->k.width) - 1;
 147         k += nkm->k.offset;
 148         if (!k)
 149                 k++;
 150
 151         m = reg >> nkm->m.shift;
 152         m &= (1 << nkm->m.width) - 1;
 153         m += nkm->m.offset;
 154         if (!m)
 155                 m++;
 156
 157         rate = parent_rate * n  * k / m;
 158
 159         if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
 160                 rate /= nkm->fixed_post_div;
 161
 162         return rate;
 163 }
 164
 165 static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
 166                                         struct clk_hw *parent_hw,
 167                                         unsigned long *parent_rate,
 168                                         unsigned long rate,
 169                                         void *data)
 170 {
 171         struct ccu_nkm *nkm = data;
 172         struct _ccu_nkm _nkm;
 173
 174         _nkm.min_n = nkm->n.min ?: 1;
 175         _nkm.max_n = nkm->n.max ?: 1 << nkm->n.width;
 176         _nkm.min_k = nkm->k.min ?: 1;
 177         _nkm.max_k = nkm->k.max ?: 1 << nkm->k.width;
 178         _nkm.min_m = 1;
 179         _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
 180
 181         if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
 182                 rate *= nkm->fixed_post_div;
 183
 184         if (!clk_hw_can_set_rate_parent(&nkm->common.hw))
 185                 rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm, &nkm->common);
 186         else
 187                 rate = ccu_nkm_find_best_with_parent_adj(&nkm->common, parent_hw, parent_rate, rate,
 188                                                          &_nkm);
 189
 190         if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
 191                 rate /= nkm->fixed_post_div;
 192
 193         return rate;
 194 }
 195
 196 static int ccu_nkm_determine_rate(struct clk_hw *hw,
 197                                   struct clk_rate_request *req)
 198 {
 199         struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
 200
 201         return ccu_mux_helper_determine_rate(&nkm->common, &nkm->mux,
 202                                              req, ccu_nkm_round_rate, nkm);
 203 }
 204
 205 static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate,
 206                            unsigned long parent_rate)
 207 {
 208         struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
 209         struct _ccu_nkm _nkm;
 210         unsigned long flags;
 211         u32 reg;
 212
 213         if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
 214                 rate *= nkm->fixed_post_div;
 215
 216         _nkm.min_n = nkm->n.min ?: 1;
 217         _nkm.max_n = nkm->n.max ?: 1 << nkm->n.width;
 218         _nkm.min_k = nkm->k.min ?: 1;
 219         _nkm.max_k = nkm->k.max ?: 1 << nkm->k.width;
 220         _nkm.min_m = 1;
 221         _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
 222
 223         ccu_nkm_find_best(parent_rate, rate, &_nkm, &nkm->common);
 224
 225         spin_lock_irqsave(nkm->common.lock, flags);
 226
 227         reg = readl(nkm->common.base + nkm->common.reg);
 228         reg &= ~GENMASK(nkm->n.width + nkm->n.shift - 1, nkm->n.shift);
 229         reg &= ~GENMASK(nkm->k.width + nkm->k.shift - 1, nkm->k.shift);
 230         reg &= ~GENMASK(nkm->m.width + nkm->m.shift - 1, nkm->m.shift);
 231
 232         reg |= (_nkm.n - nkm->n.offset) << nkm->n.shift;
 233         reg |= (_nkm.k - nkm->k.offset) << nkm->k.shift;
 234         reg |= (_nkm.m - nkm->m.offset) << nkm->m.shift;
 235         writel(reg, nkm->common.base + nkm->common.reg);
 236
 237         spin_unlock_irqrestore(nkm->common.lock, flags);
 238
 239         ccu_helper_wait_for_lock(&nkm->common, nkm->lock);
 240
 241         return 0;
 242 }
 243
 244 static u8 ccu_nkm_get_parent(struct clk_hw *hw)
 245 {
 246         struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
 247
 248         return ccu_mux_helper_get_parent(&nkm->common, &nkm->mux);
 249 }
 250
 251 static int ccu_nkm_set_parent(struct clk_hw *hw, u8 index)
 252 {
 253         struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
 254
 255         return ccu_mux_helper_set_parent(&nkm->common, &nkm->mux, index);
 256 }
 257
 258 const struct clk_ops ccu_nkm_ops = {
 259         .disable        = ccu_nkm_disable,
 260         .enable         = ccu_nkm_enable,
 261         .is_enabled     = ccu_nkm_is_enabled,
 262
 263         .get_parent     = ccu_nkm_get_parent,
 264         .set_parent     = ccu_nkm_set_parent,
 265
 266         .determine_rate = ccu_nkm_determine_rate,
 267         .recalc_rate    = ccu_nkm_recalc_rate,
 268         .set_rate       = ccu_nkm_set_rate,
 269 };
 270 EXPORT_SYMBOL_NS_GPL(ccu_nkm_ops, "SUNXI_CCU");