drivers/clk/at91/clk-usb.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
   4  */
   5
   6 #include <linux/clk-provider.h>
   7 #include <linux/clkdev.h>
   8 #include <linux/clk/at91_pmc.h>
   9 #include <linux/of.h>
  10 #include <linux/mfd/syscon.h>
  11 #include <linux/regmap.h>
  12
  13 #include "pmc.h"
  14
  15 #define SAM9X5_USB_DIV_SHIFT    8
  16 #define SAM9X5_USB_MAX_DIV      0xf
  17
  18 #define RM9200_USB_DIV_SHIFT    28
  19 #define RM9200_USB_DIV_TAB_SIZE 4
  20
  21 #define SAM9X5_USBS_MASK        GENMASK(0, 0)
  22 #define SAM9X60_USBS_MASK       GENMASK(1, 0)
  23
  24 struct at91sam9x5_clk_usb {
  25         struct clk_hw hw;
  26         struct regmap *regmap;
  27         u32 usbs_mask;
  28         u8 num_parents;
  29 };
  30
  31 #define to_at91sam9x5_clk_usb(hw) \
  32         container_of(hw, struct at91sam9x5_clk_usb, hw)
  33
  34 struct at91rm9200_clk_usb {
  35         struct clk_hw hw;
  36         struct regmap *regmap;
  37         u32 divisors[4];
  38 };
  39
  40 #define to_at91rm9200_clk_usb(hw) \
  41         container_of(hw, struct at91rm9200_clk_usb, hw)
  42
  43 static unsigned long at91sam9x5_clk_usb_recalc_rate(struct clk_hw *hw,
  44                                                     unsigned long parent_rate)
  45 {
  46         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
  47         unsigned int usbr;
  48         u8 usbdiv;
  49
  50         regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
  51         usbdiv = (usbr & AT91_PMC_OHCIUSBDIV) >> SAM9X5_USB_DIV_SHIFT;
  52
  53         return DIV_ROUND_CLOSEST(parent_rate, (usbdiv + 1));
  54 }
  55
  56 static int at91sam9x5_clk_usb_determine_rate(struct clk_hw *hw,
  57                                              struct clk_rate_request *req)
  58 {
  59         struct clk_hw *parent;
  60         long best_rate = -EINVAL;
  61         unsigned long tmp_rate;
  62         int best_diff = -1;
  63         int tmp_diff;
  64         int i;
  65
  66         for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
  67                 int div;
  68
  69                 parent = clk_hw_get_parent_by_index(hw, i);
  70                 if (!parent)
  71                         continue;
  72
  73                 for (div = 1; div < SAM9X5_USB_MAX_DIV + 2; div++) {
  74                         unsigned long tmp_parent_rate;
  75
  76                         tmp_parent_rate = req->rate * div;
  77                         tmp_parent_rate = clk_hw_round_rate(parent,
  78                                                            tmp_parent_rate);
  79                         if (!tmp_parent_rate)
  80                                 continue;
  81
  82                         tmp_rate = DIV_ROUND_CLOSEST(tmp_parent_rate, div);
  83                         if (tmp_rate < req->rate)
  84                                 tmp_diff = req->rate - tmp_rate;
  85                         else
  86                                 tmp_diff = tmp_rate - req->rate;
  87
  88                         if (best_diff < 0 || best_diff > tmp_diff) {
  89                                 best_rate = tmp_rate;
  90                                 best_diff = tmp_diff;
  91                                 req->best_parent_rate = tmp_parent_rate;
  92                                 req->best_parent_hw = parent;
  93                         }
  94
  95                         if (!best_diff || tmp_rate < req->rate)
  96                                 break;
  97                 }
  98
  99                 if (!best_diff)
 100                         break;
 101         }
 102
 103         if (best_rate < 0)
 104                 return best_rate;
 105
 106         req->rate = best_rate;
 107         return 0;
 108 }
 109
 110 static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index)
 111 {
 112         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 113
 114         if (index >= usb->num_parents)
 115                 return -EINVAL;
 116
 117         regmap_update_bits(usb->regmap, AT91_PMC_USB, usb->usbs_mask, index);
 118
 119         return 0;
 120 }
 121
 122 static u8 at91sam9x5_clk_usb_get_parent(struct clk_hw *hw)
 123 {
 124         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 125         unsigned int usbr;
 126
 127         regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
 128
 129         return usbr & usb->usbs_mask;
 130 }
 131
 132 static int at91sam9x5_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
 133                                        unsigned long parent_rate)
 134 {
 135         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 136         unsigned long div;
 137
 138         if (!rate)
 139                 return -EINVAL;
 140
 141         div = DIV_ROUND_CLOSEST(parent_rate, rate);
 142         if (div > SAM9X5_USB_MAX_DIV + 1 || !div)
 143                 return -EINVAL;
 144
 145         regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_OHCIUSBDIV,
 146                            (div - 1) << SAM9X5_USB_DIV_SHIFT);
 147
 148         return 0;
 149 }
 150
 151 static const struct clk_ops at91sam9x5_usb_ops = {
 152         .recalc_rate = at91sam9x5_clk_usb_recalc_rate,
 153         .determine_rate = at91sam9x5_clk_usb_determine_rate,
 154         .get_parent = at91sam9x5_clk_usb_get_parent,
 155         .set_parent = at91sam9x5_clk_usb_set_parent,
 156         .set_rate = at91sam9x5_clk_usb_set_rate,
 157 };
 158
 159 static int at91sam9n12_clk_usb_enable(struct clk_hw *hw)
 160 {
 161         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 162
 163         regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_USBS,
 164                            AT91_PMC_USBS);
 165
 166         return 0;
 167 }
 168
 169 static void at91sam9n12_clk_usb_disable(struct clk_hw *hw)
 170 {
 171         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 172
 173         regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_USBS, 0);
 174 }
 175
 176 static int at91sam9n12_clk_usb_is_enabled(struct clk_hw *hw)
 177 {
 178         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 179         unsigned int usbr;
 180
 181         regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
 182
 183         return usbr & AT91_PMC_USBS;
 184 }
 185
 186 static const struct clk_ops at91sam9n12_usb_ops = {
 187         .enable = at91sam9n12_clk_usb_enable,
 188         .disable = at91sam9n12_clk_usb_disable,
 189         .is_enabled = at91sam9n12_clk_usb_is_enabled,
 190         .recalc_rate = at91sam9x5_clk_usb_recalc_rate,
 191         .determine_rate = at91sam9x5_clk_usb_determine_rate,
 192         .set_rate = at91sam9x5_clk_usb_set_rate,
 193 };
 194
 195 static struct clk_hw * __init
 196 _at91sam9x5_clk_register_usb(struct regmap *regmap, const char *name,
 197                              const char **parent_names, u8 num_parents,
 198                              u32 usbs_mask)
 199 {
 200         struct at91sam9x5_clk_usb *usb;
 201         struct clk_hw *hw;
 202         struct clk_init_data init;
 203         int ret;
 204
 205         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 206         if (!usb)
 207                 return ERR_PTR(-ENOMEM);
 208
 209         init.name = name;
 210         init.ops = &at91sam9x5_usb_ops;
 211         init.parent_names = parent_names;
 212         init.num_parents = num_parents;
 213         init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
 214                      CLK_SET_RATE_PARENT;
 215
 216         usb->hw.init = &init;
 217         usb->regmap = regmap;
 218         usb->usbs_mask = usbs_mask;
 219         usb->num_parents = num_parents;
 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 }