kernel/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 USB_SOURCE_MAX          2
  21
  22 #define SAM9X5_USB_DIV_SHIFT    8
  23 #define SAM9X5_USB_MAX_DIV      0xf
  24
  25 #define RM9200_USB_DIV_SHIFT    28
  26 #define RM9200_USB_DIV_TAB_SIZE 4
  27
  28 struct at91sam9x5_clk_usb {
  29         struct clk_hw hw;
  30         struct regmap *regmap;
  31 };
  32
  33 #define to_at91sam9x5_clk_usb(hw) \
  34         container_of(hw, struct at91sam9x5_clk_usb, hw)
  35
  36 struct at91rm9200_clk_usb {
  37         struct clk_hw hw;
  38         struct regmap *regmap;
  39         u32 divisors[4];
  40 };
  41
  42 #define to_at91rm9200_clk_usb(hw) \
  43         container_of(hw, struct at91rm9200_clk_usb, hw)
  44
  45 static unsigned long at91sam9x5_clk_usb_recalc_rate(struct clk_hw *hw,
  46                                                     unsigned long parent_rate)
  47 {
  48         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
  49         unsigned int usbr;
  50         u8 usbdiv;
  51
  52         regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
  53         usbdiv = (usbr & AT91_PMC_OHCIUSBDIV) >> SAM9X5_USB_DIV_SHIFT;
  54
  55         return DIV_ROUND_CLOSEST(parent_rate, (usbdiv + 1));
  56 }
  57
  58 static int at91sam9x5_clk_usb_determine_rate(struct clk_hw *hw,
  59                                              struct clk_rate_request *req)
  60 {
  61         struct clk_hw *parent;
  62         long best_rate = -EINVAL;
  63         unsigned long tmp_rate;
  64         int best_diff = -1;
  65         int tmp_diff;
  66         int i;
  67
  68         for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
  69                 int div;
  70
  71                 parent = clk_hw_get_parent_by_index(hw, i);
  72                 if (!parent)
  73                         continue;
  74
  75                 for (div = 1; div < SAM9X5_USB_MAX_DIV + 2; div++) {
  76                         unsigned long tmp_parent_rate;
  77
  78                         tmp_parent_rate = req->rate * div;
  79                         tmp_parent_rate = clk_hw_round_rate(parent,
  80                                                            tmp_parent_rate);
  81                         tmp_rate = DIV_ROUND_CLOSEST(tmp_parent_rate, div);
  82                         if (tmp_rate < req->rate)
  83                                 tmp_diff = req->rate - tmp_rate;
  84                         else
  85                                 tmp_diff = tmp_rate - req->rate;
  86
  87                         if (best_diff < 0 || best_diff > tmp_diff) {
  88                                 best_rate = tmp_rate;
  89                                 best_diff = tmp_diff;
  90                                 req->best_parent_rate = tmp_parent_rate;
  91                                 req->best_parent_hw = parent;
  92                         }
  93
  94                         if (!best_diff || tmp_rate < req->rate)
  95                                 break;
  96                 }
  97
  98                 if (!best_diff)
  99                         break;
 100         }
 101
 102         if (best_rate < 0)
 103                 return best_rate;
 104
 105         req->rate = best_rate;
 106         return 0;
 107 }
 108
 109 static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index)
 110 {
 111         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 112
 113         if (index > 1)
 114                 return -EINVAL;
 115
 116         regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_USBS,
 117                            index ? AT91_PMC_USBS : 0);
 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 & AT91_PMC_USBS;
 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 * __init
 196 at91sam9x5_clk_register_usb(struct regmap *regmap, const char *name,
 197                             const char **parent_names, u8 num_parents)
 198 {
 199         struct at91sam9x5_clk_usb *usb;
 200         struct clk *clk = NULL;
 201         struct clk_init_data init;
 202
 203         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 204         if (!usb)
 205                 return ERR_PTR(-ENOMEM);
 206
 207         init.name = name;
 208         init.ops = &at91sam9x5_usb_ops;
 209         init.parent_names = parent_names;
 210         init.num_parents = num_parents;
 211         init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
 212                      CLK_SET_RATE_PARENT;
 213
 214         usb->hw.init = &init;
 215         usb->regmap = regmap;
 216
 217         clk = clk_register(NULL, &usb->hw);
 218         if (IS_ERR(clk))
 219                 kfree(usb);
 220
 221         return clk;
 222 }
 223
 224 static struct clk * __init
 225 at91sam9n12_clk_register_usb(struct regmap *regmap, const char *name,
 226                              const char *parent_name)
 227 {
 228         struct at91sam9x5_clk_usb *usb;
 229         struct clk *clk = NULL;
 230         struct clk_init_data init;
 231
 232         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 233         if (!usb)
 234                 return ERR_PTR(-ENOMEM);
 235
 236         init.name = name;
 237         init.ops = &at91sam9n12_usb_ops;
 238         init.parent_names = &parent_name;
 239         init.num_parents = 1;
 240         init.flags = CLK_SET_RATE_GATE | CLK_SET_RATE_PARENT;
 241
 242         usb->hw.init = &init;
 243         usb->regmap = regmap;
 244
 245         clk = clk_register(NULL, &usb->hw);
 246         if (IS_ERR(clk))
 247                 kfree(usb);
 248
 249         return clk;
 250 }
 251
 252 static unsigned long at91rm9200_clk_usb_recalc_rate(struct clk_hw *hw,
 253                                                     unsigned long parent_rate)
 254 {
 255         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 256         unsigned int pllbr;
 257         u8 usbdiv;
 258
 259         regmap_read(usb->regmap, AT91_CKGR_PLLBR, &pllbr);
 260
 261         usbdiv = (pllbr & AT91_PMC_USBDIV) >> RM9200_USB_DIV_SHIFT;
 262         if (usb->divisors[usbdiv])
 263                 return parent_rate / usb->divisors[usbdiv];
 264
 265         return 0;
 266 }
 267
 268 static long at91rm9200_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
 269                                           unsigned long *parent_rate)
 270 {
 271         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 272         struct clk_hw *parent = clk_hw_get_parent(hw);
 273         unsigned long bestrate = 0;
 274         int bestdiff = -1;
 275         unsigned long tmprate;
 276         int tmpdiff;
 277         int i = 0;
 278
 279         for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
 280                 unsigned long tmp_parent_rate;
 281
 282                 if (!usb->divisors[i])
 283                         continue;
 284
 285                 tmp_parent_rate = rate * usb->divisors[i];
 286                 tmp_parent_rate = clk_hw_round_rate(parent, tmp_parent_rate);
 287                 tmprate = DIV_ROUND_CLOSEST(tmp_parent_rate, usb->divisors[i]);
 288                 if (tmprate < rate)
 289                         tmpdiff = rate - tmprate;
 290                 else
 291                         tmpdiff = tmprate - rate;
 292
 293                 if (bestdiff < 0 || bestdiff > tmpdiff) {
 294                         bestrate = tmprate;
 295                         bestdiff = tmpdiff;
 296                         *parent_rate = tmp_parent_rate;
 297                 }
 298
 299                 if (!bestdiff)
 300                         break;
 301         }
 302
 303         return bestrate;
 304 }
 305
 306 static int at91rm9200_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
 307                                        unsigned long parent_rate)
 308 {
 309         int i;
 310         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 311         unsigned long div;
 312
 313         if (!rate)
 314                 return -EINVAL;
 315
 316         div = DIV_ROUND_CLOSEST(parent_rate, rate);
 317
 318         for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
 319                 if (usb->divisors[i] == div) {
 320                         regmap_update_bits(usb->regmap, AT91_CKGR_PLLBR,
 321                                            AT91_PMC_USBDIV,
 322                                            i << RM9200_USB_DIV_SHIFT);
 323
 324                         return 0;
 325                 }
 326         }
 327
 328         return -EINVAL;
 329 }
 330
 331 static const struct clk_ops at91rm9200_usb_ops = {
 332         .recalc_rate = at91rm9200_clk_usb_recalc_rate,
 333         .round_rate = at91rm9200_clk_usb_round_rate,
 334         .set_rate = at91rm9200_clk_usb_set_rate,
 335 };
 336
 337 static struct clk * __init
 338 at91rm9200_clk_register_usb(struct regmap *regmap, const char *name,
 339                             const char *parent_name, const u32 *divisors)
 340 {
 341         struct at91rm9200_clk_usb *usb;
 342         struct clk *clk = NULL;
 343         struct clk_init_data init;
 344
 345         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 346         if (!usb)
 347                 return ERR_PTR(-ENOMEM);
 348
 349         init.name = name;
 350         init.ops = &at91rm9200_usb_ops;
 351         init.parent_names = &parent_name;
 352         init.num_parents = 1;
 353         init.flags = CLK_SET_RATE_PARENT;
 354
 355         usb->hw.init = &init;
 356         usb->regmap = regmap;
 357         memcpy(usb->divisors, divisors, sizeof(usb->divisors));
 358
 359         clk = clk_register(NULL, &usb->hw);
 360         if (IS_ERR(clk))
 361                 kfree(usb);
 362
 363         return clk;
 364 }
 365
 366 static void __init of_at91sam9x5_clk_usb_setup(struct device_node *np)
 367 {
 368         struct clk *clk;
 369         int num_parents;
 370         const char *parent_names[USB_SOURCE_MAX];
 371         const char *name = np->name;
 372         struct regmap *regmap;
 373
 374         num_parents = of_clk_get_parent_count(np);
 375         if (num_parents <= 0 || num_parents > USB_SOURCE_MAX)
 376                 return;
 377
 378         of_clk_parent_fill(np, parent_names, num_parents);
 379
 380         of_property_read_string(np, "clock-output-names", &name);
 381
 382         regmap = syscon_node_to_regmap(of_get_parent(np));
 383         if (IS_ERR(regmap))
 384                 return;
 385
 386         clk = at91sam9x5_clk_register_usb(regmap, name, parent_names,
 387                                           num_parents);
 388         if (IS_ERR(clk))
 389                 return;
 390
 391         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 392 }
 393 CLK_OF_DECLARE(at91sam9x5_clk_usb, "atmel,at91sam9x5-clk-usb",
 394                of_at91sam9x5_clk_usb_setup);
 395
 396 static void __init of_at91sam9n12_clk_usb_setup(struct device_node *np)
 397 {
 398         struct clk *clk;
 399         const char *parent_name;
 400         const char *name = np->name;
 401         struct regmap *regmap;
 402
 403         parent_name = of_clk_get_parent_name(np, 0);
 404         if (!parent_name)
 405                 return;
 406
 407         of_property_read_string(np, "clock-output-names", &name);
 408
 409         regmap = syscon_node_to_regmap(of_get_parent(np));
 410         if (IS_ERR(regmap))
 411                 return;
 412
 413         clk = at91sam9n12_clk_register_usb(regmap, name, parent_name);
 414         if (IS_ERR(clk))
 415                 return;
 416
 417         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 418 }
 419 CLK_OF_DECLARE(at91sam9n12_clk_usb, "atmel,at91sam9n12-clk-usb",
 420                of_at91sam9n12_clk_usb_setup);
 421
 422 static void __init of_at91rm9200_clk_usb_setup(struct device_node *np)
 423 {
 424         struct clk *clk;
 425         const char *parent_name;
 426         const char *name = np->name;
 427         u32 divisors[4] = {0, 0, 0, 0};
 428         struct regmap *regmap;
 429
 430         parent_name = of_clk_get_parent_name(np, 0);
 431         if (!parent_name)
 432                 return;
 433
 434         of_property_read_u32_array(np, "atmel,clk-divisors", divisors, 4);
 435         if (!divisors[0])
 436                 return;
 437
 438         of_property_read_string(np, "clock-output-names", &name);
 439
 440         regmap = syscon_node_to_regmap(of_get_parent(np));
 441         if (IS_ERR(regmap))
 442                 return;
 443
 444         clk = at91rm9200_clk_register_usb(regmap, name, parent_name, divisors);
 445         if (IS_ERR(clk))
 446                 return;
 447
 448         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 449 }
 450 CLK_OF_DECLARE(at91rm9200_clk_usb, "atmel,at91rm9200-clk-usb",
 451                of_at91rm9200_clk_usb_setup);