drivers/clk/at91/clk-usb.c

   1 /*
   2  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  */
  10
  11 #include <linux/clk-provider.h>
  12 #include <linux/clkdev.h>
  13 #include <linux/clk/at91_pmc.h>
  14 #include <linux/of.h>
  15 #include <linux/mfd/syscon.h>
  16 #include <linux/regmap.h>
  17
  18 #include "pmc.h"
  19
  20 #define SAM9X5_USB_DIV_SHIFT    8
  21 #define SAM9X5_USB_MAX_DIV      0xf
  22
  23 #define RM9200_USB_DIV_SHIFT    28
  24 #define RM9200_USB_DIV_TAB_SIZE 4
  25
  26 #define SAM9X5_USBS_MASK        GENMASK(0, 0)
  27 #define SAM9X60_USBS_MASK       GENMASK(1, 0)
  28
  29 struct at91sam9x5_clk_usb {
  30         struct clk_hw hw;
  31         struct regmap *regmap;
  32         u32 usbs_mask;
  33 };
  34
  35 #define to_at91sam9x5_clk_usb(hw) \
  36         container_of(hw, struct at91sam9x5_clk_usb, hw)
  37
  38 struct at91rm9200_clk_usb {
  39         struct clk_hw hw;
  40         struct regmap *regmap;
  41         u32 divisors[4];
  42 };
  43
  44 #define to_at91rm9200_clk_usb(hw) \
  45         container_of(hw, struct at91rm9200_clk_usb, hw)
  46
  47 static unsigned long at91sam9x5_clk_usb_recalc_rate(struct clk_hw *hw,
  48                                                     unsigned long parent_rate)
  49 {
  50         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
  51         unsigned int usbr;
  52         u8 usbdiv;
  53
  54         regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
  55         usbdiv = (usbr & AT91_PMC_OHCIUSBDIV) >> SAM9X5_USB_DIV_SHIFT;
  56
  57         return DIV_ROUND_CLOSEST(parent_rate, (usbdiv + 1));
  58 }
  59
  60 static int at91sam9x5_clk_usb_determine_rate(struct clk_hw *hw,
  61                                              struct clk_rate_request *req)
  62 {
  63         struct clk_hw *parent;
  64         long best_rate = -EINVAL;
  65         unsigned long tmp_rate;
  66         int best_diff = -1;
  67         int tmp_diff;
  68         int i;
  69
  70         for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
  71                 int div;
  72
  73                 parent = clk_hw_get_parent_by_index(hw, i);
  74                 if (!parent)
  75                         continue;
  76
  77                 for (div = 1; div < SAM9X5_USB_MAX_DIV + 2; div++) {
  78                         unsigned long tmp_parent_rate;
  79
  80                         tmp_parent_rate = req->rate * div;
  81                         tmp_parent_rate = clk_hw_round_rate(parent,
  82                                                            tmp_parent_rate);
  83                         tmp_rate = DIV_ROUND_CLOSEST(tmp_parent_rate, div);
  84                         if (tmp_rate < req->rate)
  85                                 tmp_diff = req->rate - tmp_rate;
  86                         else
  87                                 tmp_diff = tmp_rate - req->rate;
  88
  89                         if (best_diff < 0 || best_diff > tmp_diff) {
  90                                 best_rate = tmp_rate;
  91                                 best_diff = tmp_diff;
  92                                 req->best_parent_rate = tmp_parent_rate;
  93                                 req->best_parent_hw = parent;
  94                         }
  95
  96                         if (!best_diff || tmp_rate < req->rate)
  97                                 break;
  98                 }
  99
 100                 if (!best_diff)
 101                         break;
 102         }
 103
 104         if (best_rate < 0)
 105                 return best_rate;
 106
 107         req->rate = best_rate;
 108         return 0;
 109 }
 110
 111 static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index)
 112 {
 113         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 114
 115         if (index > 1)
 116                 return -EINVAL;
 117
 118         regmap_update_bits(usb->regmap, AT91_PMC_USB, usb->usbs_mask, index);
 119
 120         return 0;
 121 }
 122
 123 static u8 at91sam9x5_clk_usb_get_parent(struct clk_hw *hw)
 124 {
 125         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 126         unsigned int usbr;
 127
 128         regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
 129
 130         return usbr & usb->usbs_mask;
 131 }
 132
 133 static int at91sam9x5_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
 134                                        unsigned long parent_rate)
 135 {
 136         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 137         unsigned long div;
 138
 139         if (!rate)
 140                 return -EINVAL;
 141
 142         div = DIV_ROUND_CLOSEST(parent_rate, rate);
 143         if (div > SAM9X5_USB_MAX_DIV + 1 || !div)
 144                 return -EINVAL;
 145
 146         regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_OHCIUSBDIV,
 147                            (div - 1) << SAM9X5_USB_DIV_SHIFT);
 148
 149         return 0;
 150 }
 151
 152 static const struct clk_ops at91sam9x5_usb_ops = {
 153         .recalc_rate = at91sam9x5_clk_usb_recalc_rate,
 154         .determine_rate = at91sam9x5_clk_usb_determine_rate,
 155         .get_parent = at91sam9x5_clk_usb_get_parent,
 156         .set_parent = at91sam9x5_clk_usb_set_parent,
 157         .set_rate = at91sam9x5_clk_usb_set_rate,
 158 };
 159
 160 static int at91sam9n12_clk_usb_enable(struct clk_hw *hw)
 161 {
 162         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 163
 164         regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_USBS,
 165                            AT91_PMC_USBS);
 166
 167         return 0;
 168 }
 169
 170 static void at91sam9n12_clk_usb_disable(struct clk_hw *hw)
 171 {
 172         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 173
 174         regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_USBS, 0);
 175 }
 176
 177 static int at91sam9n12_clk_usb_is_enabled(struct clk_hw *hw)
 178 {
 179         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 180         unsigned int usbr;
 181
 182         regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
 183
 184         return usbr & AT91_PMC_USBS;
 185 }
 186
 187 static const struct clk_ops at91sam9n12_usb_ops = {
 188         .enable = at91sam9n12_clk_usb_enable,
 189         .disable = at91sam9n12_clk_usb_disable,
 190         .is_enabled = at91sam9n12_clk_usb_is_enabled,
 191         .recalc_rate = at91sam9x5_clk_usb_recalc_rate,
 192         .determine_rate = at91sam9x5_clk_usb_determine_rate,
 193         .set_rate = at91sam9x5_clk_usb_set_rate,
 194 };
 195
 196 static struct clk_hw * __init
 197 _at91sam9x5_clk_register_usb(struct regmap *regmap, const char *name,
 198                              const char **parent_names, u8 num_parents,
 199                              u32 usbs_mask)
 200 {
 201         struct at91sam9x5_clk_usb *usb;
 202         struct clk_hw *hw;
 203         struct clk_init_data init;
 204         int ret;
 205
 206         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 207         if (!usb)
 208                 return ERR_PTR(-ENOMEM);
 209
 210         init.name = name;
 211         init.ops = &at91sam9x5_usb_ops;
 212         init.parent_names = parent_names;
 213         init.num_parents = num_parents;
 214         init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
 215                      CLK_SET_RATE_PARENT;
 216
 217         usb->hw.init = &init;
 218         usb->regmap = regmap;
 219         usb->usbs_mask = SAM9X5_USBS_MASK;
 220
 221         hw = &usb->hw;
 222         ret = clk_hw_register(NULL, &usb->hw);
 223         if (ret) {
 224                 kfree(usb);
 225                 hw = ERR_PTR(ret);
 226         }
 227
 228         return hw;
 229 }
 230
 231 struct clk_hw * __init
 232 at91sam9x5_clk_register_usb(struct regmap *regmap, const char *name,
 233                             const char **parent_names, u8 num_parents)
 234 {
 235         return _at91sam9x5_clk_register_usb(regmap, name, parent_names,
 236                                             num_parents, SAM9X5_USBS_MASK);
 237 }
 238
 239 struct clk_hw * __init
 240 sam9x60_clk_register_usb(struct regmap *regmap, const char *name,
 241                          const char **parent_names, u8 num_parents)
 242 {
 243         return _at91sam9x5_clk_register_usb(regmap, name, parent_names,
 244                                             num_parents, SAM9X60_USBS_MASK);
 245 }
 246
 247 struct clk_hw * __init
 248 at91sam9n12_clk_register_usb(struct regmap *regmap, const char *name,
 249                              const char *parent_name)
 250 {
 251         struct at91sam9x5_clk_usb *usb;
 252         struct clk_hw *hw;
 253         struct clk_init_data init;
 254         int ret;
 255
 256         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 257         if (!usb)
 258                 return ERR_PTR(-ENOMEM);
 259
 260         init.name = name;
 261         init.ops = &at91sam9n12_usb_ops;
 262         init.parent_names = &parent_name;
 263         init.num_parents = 1;
 264         init.flags = CLK_SET_RATE_GATE | CLK_SET_RATE_PARENT;
 265
 266         usb->hw.init = &init;
 267         usb->regmap = regmap;
 268
 269         hw = &usb->hw;
 270         ret = clk_hw_register(NULL, &usb->hw);
 271         if (ret) {
 272                 kfree(usb);
 273                 hw = ERR_PTR(ret);
 274         }
 275
 276         return hw;
 277 }
 278
 279 static unsigned long at91rm9200_clk_usb_recalc_rate(struct clk_hw *hw,
 280                                                     unsigned long parent_rate)
 281 {
 282         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 283         unsigned int pllbr;
 284         u8 usbdiv;
 285
 286         regmap_read(usb->regmap, AT91_CKGR_PLLBR, &pllbr);
 287
 288         usbdiv = (pllbr & AT91_PMC_USBDIV) >> RM9200_USB_DIV_SHIFT;
 289         if (usb->divisors[usbdiv])
 290                 return parent_rate / usb->divisors[usbdiv];
 291
 292         return 0;
 293 }
 294
 295 static long at91rm9200_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
 296                                           unsigned long *parent_rate)
 297 {
 298         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 299         struct clk_hw *parent = clk_hw_get_parent(hw);
 300         unsigned long bestrate = 0;
 301         int bestdiff = -1;
 302         unsigned long tmprate;
 303         int tmpdiff;
 304         int i = 0;
 305
 306         for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
 307                 unsigned long tmp_parent_rate;
 308
 309                 if (!usb->divisors[i])
 310                         continue;
 311
 312                 tmp_parent_rate = rate * usb->divisors[i];
 313                 tmp_parent_rate = clk_hw_round_rate(parent, tmp_parent_rate);
 314                 tmprate = DIV_ROUND_CLOSEST(tmp_parent_rate, usb->divisors[i]);
 315                 if (tmprate < rate)
 316                         tmpdiff = rate - tmprate;
 317                 else
 318                         tmpdiff = tmprate - rate;
 319
 320                 if (bestdiff < 0 || bestdiff > tmpdiff) {
 321                         bestrate = tmprate;
 322                         bestdiff = tmpdiff;
 323                         *parent_rate = tmp_parent_rate;
 324                 }
 325
 326                 if (!bestdiff)
 327                         break;
 328         }
 329
 330         return bestrate;
 331 }
 332
 333 static int at91rm9200_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
 334                                        unsigned long parent_rate)
 335 {
 336         int i;
 337         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 338         unsigned long div;
 339
 340         if (!rate)
 341                 return -EINVAL;
 342
 343         div = DIV_ROUND_CLOSEST(parent_rate, rate);
 344
 345         for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
 346                 if (usb->divisors[i] == div) {
 347                         regmap_update_bits(usb->regmap, AT91_CKGR_PLLBR,
 348                                            AT91_PMC_USBDIV,
 349                                            i << RM9200_USB_DIV_SHIFT);
 350
 351                         return 0;
 352                 }
 353         }
 354
 355         return -EINVAL;
 356 }
 357
 358 static const struct clk_ops at91rm9200_usb_ops = {
 359         .recalc_rate = at91rm9200_clk_usb_recalc_rate,
 360         .round_rate = at91rm9200_clk_usb_round_rate,
 361         .set_rate = at91rm9200_clk_usb_set_rate,
 362 };
 363
 364 struct clk_hw * __init
 365 at91rm9200_clk_register_usb(struct regmap *regmap, const char *name,
 366                             const char *parent_name, const u32 *divisors)
 367 {
 368         struct at91rm9200_clk_usb *usb;
 369         struct clk_hw *hw;
 370         struct clk_init_data init;
 371         int ret;
 372
 373         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 374         if (!usb)
 375                 return ERR_PTR(-ENOMEM);
 376
 377         init.name = name;
 378         init.ops = &at91rm9200_usb_ops;
 379         init.parent_names = &parent_name;
 380         init.num_parents = 1;
 381         init.flags = CLK_SET_RATE_PARENT;
 382
 383         usb->hw.init = &init;
 384         usb->regmap = regmap;
 385         memcpy(usb->divisors, divisors, sizeof(usb->divisors));
 386
 387         hw = &usb->hw;
 388         ret = clk_hw_register(NULL, &usb->hw);
 389         if (ret) {
 390                 kfree(usb);
 391                 hw = ERR_PTR(ret);
 392         }
 393
 394         return hw;
 395 }