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/of_address.h>
  16 #include <linux/io.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 at91_pmc *pmc;
  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 at91_pmc *pmc;
  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         u32 tmp;
  49         u8 usbdiv;
  50         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
  51         struct at91_pmc *pmc = usb->pmc;
  52
  53         tmp = pmc_read(pmc, AT91_PMC_USB);
  54         usbdiv = (tmp & AT91_PMC_OHCIUSBDIV) >> SAM9X5_USB_DIV_SHIFT;
  55
  56         return DIV_ROUND_CLOSEST(parent_rate, (usbdiv + 1));
  57 }
  58
  59 static int at91sam9x5_clk_usb_determine_rate(struct clk_hw *hw,
  60                                              struct clk_rate_request *req)
  61 {
  62         struct clk_hw *parent;
  63         long best_rate = -EINVAL;
  64         unsigned long tmp_rate;
  65         int best_diff = -1;
  66         int tmp_diff;
  67         int i;
  68
  69         for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
  70                 int div;
  71
  72                 parent = clk_hw_get_parent_by_index(hw, i);
  73                 if (!parent)
  74                         continue;
  75
  76                 for (div = 1; div < SAM9X5_USB_MAX_DIV + 2; div++) {
  77                         unsigned long tmp_parent_rate;
  78
  79                         tmp_parent_rate = req->rate * div;
  80                         tmp_parent_rate = clk_hw_round_rate(parent,
  81                                                            tmp_parent_rate);
  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         u32 tmp;
 113         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 114         struct at91_pmc *pmc = usb->pmc;
 115
 116         if (index > 1)
 117                 return -EINVAL;
 118         tmp = pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_USBS;
 119         if (index)
 120                 tmp |= AT91_PMC_USBS;
 121         pmc_write(pmc, AT91_PMC_USB, tmp);
 122         return 0;
 123 }
 124
 125 static u8 at91sam9x5_clk_usb_get_parent(struct clk_hw *hw)
 126 {
 127         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 128         struct at91_pmc *pmc = usb->pmc;
 129
 130         return pmc_read(pmc, AT91_PMC_USB) & AT91_PMC_USBS;
 131 }
 132
 133 static int at91sam9x5_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
 134                                        unsigned long parent_rate)
 135 {
 136         u32 tmp;
 137         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 138         struct at91_pmc *pmc = usb->pmc;
 139         unsigned long div;
 140
 141         if (!rate)
 142                 return -EINVAL;
 143
 144         div = DIV_ROUND_CLOSEST(parent_rate, rate);
 145         if (div > SAM9X5_USB_MAX_DIV + 1 || !div)
 146                 return -EINVAL;
 147
 148         tmp = pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_OHCIUSBDIV;
 149         tmp |= (div - 1) << SAM9X5_USB_DIV_SHIFT;
 150         pmc_write(pmc, AT91_PMC_USB, tmp);
 151
 152         return 0;
 153 }
 154
 155 static const struct clk_ops at91sam9x5_usb_ops = {
 156         .recalc_rate = at91sam9x5_clk_usb_recalc_rate,
 157         .determine_rate = at91sam9x5_clk_usb_determine_rate,
 158         .get_parent = at91sam9x5_clk_usb_get_parent,
 159         .set_parent = at91sam9x5_clk_usb_set_parent,
 160         .set_rate = at91sam9x5_clk_usb_set_rate,
 161 };
 162
 163 static int at91sam9n12_clk_usb_enable(struct clk_hw *hw)
 164 {
 165         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 166         struct at91_pmc *pmc = usb->pmc;
 167
 168         pmc_write(pmc, AT91_PMC_USB,
 169                   pmc_read(pmc, AT91_PMC_USB) | AT91_PMC_USBS);
 170         return 0;
 171 }
 172
 173 static void at91sam9n12_clk_usb_disable(struct clk_hw *hw)
 174 {
 175         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 176         struct at91_pmc *pmc = usb->pmc;
 177
 178         pmc_write(pmc, AT91_PMC_USB,
 179                   pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_USBS);
 180 }
 181
 182 static int at91sam9n12_clk_usb_is_enabled(struct clk_hw *hw)
 183 {
 184         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 185         struct at91_pmc *pmc = usb->pmc;
 186
 187         return !!(pmc_read(pmc, AT91_PMC_USB) & AT91_PMC_USBS);
 188 }
 189
 190 static const struct clk_ops at91sam9n12_usb_ops = {
 191         .enable = at91sam9n12_clk_usb_enable,
 192         .disable = at91sam9n12_clk_usb_disable,
 193         .is_enabled = at91sam9n12_clk_usb_is_enabled,
 194         .recalc_rate = at91sam9x5_clk_usb_recalc_rate,
 195         .determine_rate = at91sam9x5_clk_usb_determine_rate,
 196         .set_rate = at91sam9x5_clk_usb_set_rate,
 197 };
 198
 199 static struct clk * __init
 200 at91sam9x5_clk_register_usb(struct at91_pmc *pmc, const char *name,
 201                             const char **parent_names, u8 num_parents)
 202 {
 203         struct at91sam9x5_clk_usb *usb;
 204         struct clk *clk = NULL;
 205         struct clk_init_data init;
 206
 207         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 208         if (!usb)
 209                 return ERR_PTR(-ENOMEM);
 210
 211         init.name = name;
 212         init.ops = &at91sam9x5_usb_ops;
 213         init.parent_names = parent_names;
 214         init.num_parents = num_parents;
 215         init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
 216                      CLK_SET_RATE_PARENT;
 217
 218         usb->hw.init = &init;
 219         usb->pmc = pmc;
 220
 221         clk = clk_register(NULL, &usb->hw);
 222         if (IS_ERR(clk))
 223                 kfree(usb);
 224
 225         return clk;
 226 }
 227
 228 static struct clk * __init
 229 at91sam9n12_clk_register_usb(struct at91_pmc *pmc, const char *name,
 230                              const char *parent_name)
 231 {
 232         struct at91sam9x5_clk_usb *usb;
 233         struct clk *clk = NULL;
 234         struct clk_init_data init;
 235
 236         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 237         if (!usb)
 238                 return ERR_PTR(-ENOMEM);
 239
 240         init.name = name;
 241         init.ops = &at91sam9n12_usb_ops;
 242         init.parent_names = &parent_name;
 243         init.num_parents = 1;
 244         init.flags = CLK_SET_RATE_GATE | CLK_SET_RATE_PARENT;
 245
 246         usb->hw.init = &init;
 247         usb->pmc = pmc;
 248
 249         clk = clk_register(NULL, &usb->hw);
 250         if (IS_ERR(clk))
 251                 kfree(usb);
 252
 253         return clk;
 254 }
 255
 256 static unsigned long at91rm9200_clk_usb_recalc_rate(struct clk_hw *hw,
 257                                                     unsigned long parent_rate)
 258 {
 259         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 260         struct at91_pmc *pmc = usb->pmc;
 261         u32 tmp;
 262         u8 usbdiv;
 263
 264         tmp = pmc_read(pmc, AT91_CKGR_PLLBR);
 265         usbdiv = (tmp & AT91_PMC_USBDIV) >> RM9200_USB_DIV_SHIFT;
 266         if (usb->divisors[usbdiv])
 267                 return parent_rate / usb->divisors[usbdiv];
 268
 269         return 0;
 270 }
 271
 272 static long at91rm9200_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
 273                                           unsigned long *parent_rate)
 274 {
 275         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 276         struct clk_hw *parent = clk_hw_get_parent(hw);
 277         unsigned long bestrate = 0;
 278         int bestdiff = -1;
 279         unsigned long tmprate;
 280         int tmpdiff;
 281         int i = 0;
 282
 283         for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
 284                 unsigned long tmp_parent_rate;
 285
 286                 if (!usb->divisors[i])
 287                         continue;
 288
 289                 tmp_parent_rate = rate * usb->divisors[i];
 290                 tmp_parent_rate = clk_hw_round_rate(parent, tmp_parent_rate);
 291                 tmprate = DIV_ROUND_CLOSEST(tmp_parent_rate, usb->divisors[i]);
 292                 if (tmprate < rate)
 293                         tmpdiff = rate - tmprate;
 294                 else
 295                         tmpdiff = tmprate - rate;
 296
 297                 if (bestdiff < 0 || bestdiff > tmpdiff) {
 298                         bestrate = tmprate;
 299                         bestdiff = tmpdiff;
 300                         *parent_rate = tmp_parent_rate;
 301                 }
 302
 303                 if (!bestdiff)
 304                         break;
 305         }
 306
 307         return bestrate;
 308 }
 309
 310 static int at91rm9200_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
 311                                        unsigned long parent_rate)
 312 {
 313         u32 tmp;
 314         int i;
 315         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 316         struct at91_pmc *pmc = usb->pmc;
 317         unsigned long div;
 318
 319         if (!rate)
 320                 return -EINVAL;
 321
 322         div = DIV_ROUND_CLOSEST(parent_rate, rate);
 323
 324         for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
 325                 if (usb->divisors[i] == div) {
 326                         tmp = pmc_read(pmc, AT91_CKGR_PLLBR) &
 327                               ~AT91_PMC_USBDIV;
 328                         tmp |= i << RM9200_USB_DIV_SHIFT;
 329                         pmc_write(pmc, AT91_CKGR_PLLBR, tmp);
 330                         return 0;
 331                 }
 332         }
 333
 334         return -EINVAL;
 335 }
 336
 337 static const struct clk_ops at91rm9200_usb_ops = {
 338         .recalc_rate = at91rm9200_clk_usb_recalc_rate,
 339         .round_rate = at91rm9200_clk_usb_round_rate,
 340         .set_rate = at91rm9200_clk_usb_set_rate,
 341 };
 342
 343 static struct clk * __init
 344 at91rm9200_clk_register_usb(struct at91_pmc *pmc, const char *name,
 345                             const char *parent_name, const u32 *divisors)
 346 {
 347         struct at91rm9200_clk_usb *usb;
 348         struct clk *clk = NULL;
 349         struct clk_init_data init;
 350
 351         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 352         if (!usb)
 353                 return ERR_PTR(-ENOMEM);
 354
 355         init.name = name;
 356         init.ops = &at91rm9200_usb_ops;
 357         init.parent_names = &parent_name;
 358         init.num_parents = 1;
 359         init.flags = CLK_SET_RATE_PARENT;
 360
 361         usb->hw.init = &init;
 362         usb->pmc = pmc;
 363         memcpy(usb->divisors, divisors, sizeof(usb->divisors));
 364
 365         clk = clk_register(NULL, &usb->hw);
 366         if (IS_ERR(clk))
 367                 kfree(usb);
 368
 369         return clk;
 370 }
 371
 372 void __init of_at91sam9x5_clk_usb_setup(struct device_node *np,
 373                                         struct at91_pmc *pmc)
 374 {
 375         struct clk *clk;
 376         int num_parents;
 377         const char *parent_names[USB_SOURCE_MAX];
 378         const char *name = np->name;
 379
 380         num_parents = of_clk_get_parent_count(np);
 381         if (num_parents <= 0 || num_parents > USB_SOURCE_MAX)
 382                 return;
 383
 384         of_clk_parent_fill(np, parent_names, num_parents);
 385
 386         of_property_read_string(np, "clock-output-names", &name);
 387
 388         clk = at91sam9x5_clk_register_usb(pmc, name, parent_names, num_parents);
 389         if (IS_ERR(clk))
 390                 return;
 391
 392         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 393 }
 394
 395 void __init of_at91sam9n12_clk_usb_setup(struct device_node *np,
 396                                          struct at91_pmc *pmc)
 397 {
 398         struct clk *clk;
 399         const char *parent_name;
 400         const char *name = np->name;
 401
 402         parent_name = of_clk_get_parent_name(np, 0);
 403         if (!parent_name)
 404                 return;
 405
 406         of_property_read_string(np, "clock-output-names", &name);
 407
 408         clk = at91sam9n12_clk_register_usb(pmc, name, parent_name);
 409         if (IS_ERR(clk))
 410                 return;
 411
 412         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 413 }
 414
 415 void __init of_at91rm9200_clk_usb_setup(struct device_node *np,
 416                                         struct at91_pmc *pmc)
 417 {
 418         struct clk *clk;
 419         const char *parent_name;
 420         const char *name = np->name;
 421         u32 divisors[4] = {0, 0, 0, 0};
 422
 423         parent_name = of_clk_get_parent_name(np, 0);
 424         if (!parent_name)
 425                 return;
 426
 427         of_property_read_u32_array(np, "atmel,clk-divisors", divisors, 4);
 428         if (!divisors[0])
 429                 return;
 430
 431         of_property_read_string(np, "clock-output-names", &name);
 432
 433         clk = at91rm9200_clk_register_usb(pmc, name, parent_name, divisors);
 434         if (IS_ERR(clk))
 435                 return;
 436
 437         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 438 }