target/linux/sunxi/patches-4.9/0003-clk-sunxi-ng-Remove-the-use-of-rational-computations.patch

   1 From ee28648cb2b4d4ab5c2eb8199ea86675fe19016b Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime.ripard@free-electrons.com>
   3 Date: Thu, 29 Sep 2016 22:53:12 +0200
   4 Subject: clk: sunxi-ng: Remove the use of rational computations
   5
   6 While the rational library works great, it doesn't really allow us to add
   7 more constraints, like the minimum.
   8
   9 Remove that in order to be able to deal with the constraints we'll need.
  10
  11 Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
  12 Acked-by: Chen-Yu Tsai <wens@csie.org>
  13 ---
  14  drivers/clk/sunxi-ng/Kconfig    |  3 ---
  15  drivers/clk/sunxi-ng/ccu_nkm.c  | 31 ++++++++++++-----------
  16  drivers/clk/sunxi-ng/ccu_nkmp.c | 37 ++++++++++++++--------------
  17  drivers/clk/sunxi-ng/ccu_nm.c   | 54 +++++++++++++++++++++++++++++++----------
  18  4 files changed, 74 insertions(+), 51 deletions(-)
  19
  20 --- a/drivers/clk/sunxi-ng/Kconfig
  21 +++ b/drivers/clk/sunxi-ng/Kconfig
  22 @@ -36,17 +36,14 @@ config SUNXI_CCU_NK
  23
  24  config SUNXI_CCU_NKM
  25         bool
  26 -       select RATIONAL
  27         select SUNXI_CCU_GATE
  28
  29  config SUNXI_CCU_NKMP
  30         bool
  31 -       select RATIONAL
  32         select SUNXI_CCU_GATE
  33
  34  config SUNXI_CCU_NM
  35         bool
  36 -       select RATIONAL
  37         select SUNXI_CCU_FRAC
  38         select SUNXI_CCU_GATE
  39
  40 --- a/drivers/clk/sunxi-ng/ccu_nkm.c
  41 +++ b/drivers/clk/sunxi-ng/ccu_nkm.c
  42 @@ -9,7 +9,6 @@
  43   */
  44
  45  #include <linux/clk-provider.h>
  46 -#include <linux/rational.h>
  47
  48  #include "ccu_gate.h"
  49  #include "ccu_nkm.h"
  50 @@ -28,21 +27,21 @@ static void ccu_nkm_find_best(unsigned l
  51         unsigned long _n, _k, _m;
  52
  53         for (_k = 1; _k <= nkm->max_k; _k++) {
  54 -               unsigned long tmp_rate;
  55 -
  56 -               rational_best_approximation(rate / _k, parent,
  57 -                                           nkm->max_n, nkm->max_m, &_n, &_m);
  58 -
  59 -               tmp_rate = parent * _n * _k / _m;
  60 -
  61 -               if (tmp_rate > rate)
  62 -                       continue;
  63 -
  64 -               if ((rate - tmp_rate) < (rate - best_rate)) {
  65 -                       best_rate = tmp_rate;
  66 -                       best_n = _n;
  67 -                       best_k = _k;
  68 -                       best_m = _m;
  69 +               for (_n = 1; _n <= nkm->max_n; _n++) {
  70 +                       for (_m = 1; _n <= nkm->max_m; _m++) {
  71 +                               unsigned long tmp_rate;
  72 +
  73 +                               tmp_rate = parent * _n * _k / _m;
  74 +
  75 +                               if (tmp_rate > rate)
  76 +                                       continue;
  77 +                               if ((rate - tmp_rate) < (rate - best_rate)) {
  78 +                                       best_rate = tmp_rate;
  79 +                                       best_n = _n;
  80 +                                       best_k = _k;
  81 +                                       best_m = _m;
  82 +                               }
  83 +                       }
  84                 }
  85         }
  86
  87 --- a/drivers/clk/sunxi-ng/ccu_nkmp.c
  88 +++ b/drivers/clk/sunxi-ng/ccu_nkmp.c
  89 @@ -9,7 +9,6 @@
  90   */
  91
  92  #include <linux/clk-provider.h>
  93 -#include <linux/rational.h>
  94
  95  #include "ccu_gate.h"
  96  #include "ccu_nkmp.h"
  97 @@ -29,24 +28,24 @@ static void ccu_nkmp_find_best(unsigned
  98         unsigned long _n, _k, _m, _p;
  99
 100         for (_k = 1; _k <= nkmp->max_k; _k++) {
 101 -               for (_p = 1; _p <= nkmp->max_p; _p <<= 1) {
 102 -                       unsigned long tmp_rate;
 103 -
 104 -                       rational_best_approximation(rate / _k, parent / _p,
 105 -                                                   nkmp->max_n, nkmp->max_m,
 106 -                                                   &_n, &_m);
 107 -
 108 -                       tmp_rate = parent * _n * _k / (_m * _p);
 109 -
 110 -                       if (tmp_rate > rate)
 111 -                               continue;
 112 -
 113 -                       if ((rate - tmp_rate) < (rate - best_rate)) {
 114 -                               best_rate = tmp_rate;
 115 -                               best_n = _n;
 116 -                               best_k = _k;
 117 -                               best_m = _m;
 118 -                               best_p = _p;
 119 +               for (_n = 1; _n <= nkmp->max_n; _n++) {
 120 +                       for (_m = 1; _n <= nkmp->max_m; _m++) {
 121 +                               for (_p = 1; _p <= nkmp->max_p; _p <<= 1) {
 122 +                                       unsigned long tmp_rate;
 123 +
 124 +                                       tmp_rate = parent * _n * _k / (_m * _p);
 125 +
 126 +                                       if (tmp_rate > rate)
 127 +                                               continue;
 128 +
 129 +                                       if ((rate - tmp_rate) < (rate - best_rate)) {
 130 +                                               best_rate = tmp_rate;
 131 +                                               best_n = _n;
 132 +                                               best_k = _k;
 133 +                                               best_m = _m;
 134 +                                               best_p = _p;
 135 +                                       }
 136 +                               }
 137                         }
 138                 }
 139         }
 140 --- a/drivers/clk/sunxi-ng/ccu_nm.c
 141 +++ b/drivers/clk/sunxi-ng/ccu_nm.c
 142 @@ -9,12 +9,42 @@
 143   */
 144
 145  #include <linux/clk-provider.h>
 146 -#include <linux/rational.h>
 147
 148  #include "ccu_frac.h"
 149  #include "ccu_gate.h"
 150  #include "ccu_nm.h"
 151
 152 +struct _ccu_nm {
 153 +       unsigned long   n, max_n;
 154 +       unsigned long   m, max_m;
 155 +};
 156 +
 157 +static void ccu_nm_find_best(unsigned long parent, unsigned long rate,
 158 +                            struct _ccu_nm *nm)
 159 +{
 160 +       unsigned long best_rate = 0;
 161 +       unsigned long best_n = 0, best_m = 0;
 162 +       unsigned long _n, _m;
 163 +
 164 +       for (_n = 1; _n <= nm->max_n; _n++) {
 165 +               for (_m = 1; _n <= nm->max_m; _m++) {
 166 +                       unsigned long tmp_rate = parent * _n  / _m;
 167 +
 168 +                       if (tmp_rate > rate)
 169 +                               continue;
 170 +
 171 +                       if ((rate - tmp_rate) < (rate - best_rate)) {
 172 +                               best_rate = tmp_rate;
 173 +                               best_n = _n;
 174 +                               best_m = _m;
 175 +                       }
 176 +               }
 177 +       }
 178 +
 179 +       nm->n = best_n;
 180 +       nm->m = best_m;
 181 +}
 182 +
 183  static void ccu_nm_disable(struct clk_hw *hw)
 184  {
 185         struct ccu_nm *nm = hw_to_ccu_nm(hw);
 186 @@ -61,24 +91,22 @@ static long ccu_nm_round_rate(struct clk
 187                               unsigned long *parent_rate)
 188  {
 189         struct ccu_nm *nm = hw_to_ccu_nm(hw);
 190 -       unsigned long max_n, max_m;
 191 -       unsigned long n, m;
 192 +       struct _ccu_nm _nm;
 193
 194 -       max_n = 1 << nm->n.width;
 195 -       max_m = nm->m.max ?: 1 << nm->m.width;
 196 +       _nm.max_n = 1 << nm->n.width;
 197 +       _nm.max_m = nm->m.max ?: 1 << nm->m.width;
 198
 199 -       rational_best_approximation(rate, *parent_rate, max_n, max_m, &n, &m);
 200 +       ccu_nm_find_best(*parent_rate, rate, &_nm);
 201
 202 -       return *parent_rate * n / m;
 203 +       return *parent_rate * _nm.n / _nm.m;
 204  }
 205
 206  static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate,
 207                            unsigned long parent_rate)
 208  {
 209         struct ccu_nm *nm = hw_to_ccu_nm(hw);
 210 +       struct _ccu_nm _nm;
 211         unsigned long flags;
 212 -       unsigned long max_n, max_m;
 213 -       unsigned long n, m;
 214         u32 reg;
 215
 216         if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate))
 217 @@ -86,10 +114,10 @@ static int ccu_nm_set_rate(struct clk_hw
 218         else
 219                 ccu_frac_helper_disable(&nm->common, &nm->frac);
 220
 221 -       max_n = 1 << nm->n.width;
 222 -       max_m = nm->m.max ?: 1 << nm->m.width;
 223 +       _nm.max_n = 1 << nm->n.width;
 224 +       _nm.max_m = nm->m.max ?: 1 << nm->m.width;
 225
 226 -       rational_best_approximation(rate, parent_rate, max_n, max_m, &n, &m);
 227 +       ccu_nm_find_best(parent_rate, rate, &_nm);
 228
 229         spin_lock_irqsave(nm->common.lock, flags);
 230
 231 @@ -97,7 +125,7 @@ static int ccu_nm_set_rate(struct clk_hw
 232         reg &= ~GENMASK(nm->n.width + nm->n.shift - 1, nm->n.shift);
 233         reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift);
 234
 235 -       writel(reg | ((m - 1) << nm->m.shift) | ((n - 1) << nm->n.shift),
 236 +       writel(reg | ((_nm.m - 1) << nm->m.shift) | ((_nm.n - 1) << nm->n.shift),
 237                nm->common.base + nm->common.reg);
 238
 239         spin_unlock_irqrestore(nm->common.lock, flags);