linux/drivers/clk/at91/clk-usb.c
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   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
  28struct 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
  36struct 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
  45static 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
  58static 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
 109static 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
 122static 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
 132static 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
 151static 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
 159static 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
 169static 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
 176static 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
 186static 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
 195static struct clk_hw * __init
 196at91sam9x5_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_hw *hw;
 201        struct clk_init_data init;
 202        int ret;
 203
 204        usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 205        if (!usb)
 206                return ERR_PTR(-ENOMEM);
 207
 208        init.name = name;
 209        init.ops = &at91sam9x5_usb_ops;
 210        init.parent_names = parent_names;
 211        init.num_parents = num_parents;
 212        init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
 213                     CLK_SET_RATE_PARENT;
 214
 215        usb->hw.init = &init;
 216        usb->regmap = regmap;
 217
 218        hw = &usb->hw;
 219        ret = clk_hw_register(NULL, &usb->hw);
 220        if (ret) {
 221                kfree(usb);
 222                hw = ERR_PTR(ret);
 223        }
 224
 225        return hw;
 226}
 227
 228static struct clk_hw * __init
 229at91sam9n12_clk_register_usb(struct regmap *regmap, const char *name,
 230                             const char *parent_name)
 231{
 232        struct at91sam9x5_clk_usb *usb;
 233        struct clk_hw *hw;
 234        struct clk_init_data init;
 235        int ret;
 236
 237        usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 238        if (!usb)
 239                return ERR_PTR(-ENOMEM);
 240
 241        init.name = name;
 242        init.ops = &at91sam9n12_usb_ops;
 243        init.parent_names = &parent_name;
 244        init.num_parents = 1;
 245        init.flags = CLK_SET_RATE_GATE | CLK_SET_RATE_PARENT;
 246
 247        usb->hw.init = &init;
 248        usb->regmap = regmap;
 249
 250        hw = &usb->hw;
 251        ret = clk_hw_register(NULL, &usb->hw);
 252        if (ret) {
 253                kfree(usb);
 254                hw = ERR_PTR(ret);
 255        }
 256
 257        return hw;
 258}
 259
 260static unsigned long at91rm9200_clk_usb_recalc_rate(struct clk_hw *hw,
 261                                                    unsigned long parent_rate)
 262{
 263        struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 264        unsigned int pllbr;
 265        u8 usbdiv;
 266
 267        regmap_read(usb->regmap, AT91_CKGR_PLLBR, &pllbr);
 268
 269        usbdiv = (pllbr & AT91_PMC_USBDIV) >> RM9200_USB_DIV_SHIFT;
 270        if (usb->divisors[usbdiv])
 271                return parent_rate / usb->divisors[usbdiv];
 272
 273        return 0;
 274}
 275
 276static long at91rm9200_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
 277                                          unsigned long *parent_rate)
 278{
 279        struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 280        struct clk_hw *parent = clk_hw_get_parent(hw);
 281        unsigned long bestrate = 0;
 282        int bestdiff = -1;
 283        unsigned long tmprate;
 284        int tmpdiff;
 285        int i = 0;
 286
 287        for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
 288                unsigned long tmp_parent_rate;
 289
 290                if (!usb->divisors[i])
 291                        continue;
 292
 293                tmp_parent_rate = rate * usb->divisors[i];
 294                tmp_parent_rate = clk_hw_round_rate(parent, tmp_parent_rate);
 295                tmprate = DIV_ROUND_CLOSEST(tmp_parent_rate, usb->divisors[i]);
 296                if (tmprate < rate)
 297                        tmpdiff = rate - tmprate;
 298                else
 299                        tmpdiff = tmprate - rate;
 300
 301                if (bestdiff < 0 || bestdiff > tmpdiff) {
 302                        bestrate = tmprate;
 303                        bestdiff = tmpdiff;
 304                        *parent_rate = tmp_parent_rate;
 305                }
 306
 307                if (!bestdiff)
 308                        break;
 309        }
 310
 311        return bestrate;
 312}
 313
 314static int at91rm9200_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
 315                                       unsigned long parent_rate)
 316{
 317        int i;
 318        struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 319        unsigned long div;
 320
 321        if (!rate)
 322                return -EINVAL;
 323
 324        div = DIV_ROUND_CLOSEST(parent_rate, rate);
 325
 326        for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
 327                if (usb->divisors[i] == div) {
 328                        regmap_update_bits(usb->regmap, AT91_CKGR_PLLBR,
 329                                           AT91_PMC_USBDIV,
 330                                           i << RM9200_USB_DIV_SHIFT);
 331
 332                        return 0;
 333                }
 334        }
 335
 336        return -EINVAL;
 337}
 338
 339static const struct clk_ops at91rm9200_usb_ops = {
 340        .recalc_rate = at91rm9200_clk_usb_recalc_rate,
 341        .round_rate = at91rm9200_clk_usb_round_rate,
 342        .set_rate = at91rm9200_clk_usb_set_rate,
 343};
 344
 345static struct clk_hw * __init
 346at91rm9200_clk_register_usb(struct regmap *regmap, const char *name,
 347                            const char *parent_name, const u32 *divisors)
 348{
 349        struct at91rm9200_clk_usb *usb;
 350        struct clk_hw *hw;
 351        struct clk_init_data init;
 352        int ret;
 353
 354        usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 355        if (!usb)
 356                return ERR_PTR(-ENOMEM);
 357
 358        init.name = name;
 359        init.ops = &at91rm9200_usb_ops;
 360        init.parent_names = &parent_name;
 361        init.num_parents = 1;
 362        init.flags = CLK_SET_RATE_PARENT;
 363
 364        usb->hw.init = &init;
 365        usb->regmap = regmap;
 366        memcpy(usb->divisors, divisors, sizeof(usb->divisors));
 367
 368        hw = &usb->hw;
 369        ret = clk_hw_register(NULL, &usb->hw);
 370        if (ret) {
 371                kfree(usb);
 372                hw = ERR_PTR(ret);
 373        }
 374
 375        return hw;
 376}
 377
 378static void __init of_at91sam9x5_clk_usb_setup(struct device_node *np)
 379{
 380        struct clk_hw *hw;
 381        unsigned int num_parents;
 382        const char *parent_names[USB_SOURCE_MAX];
 383        const char *name = np->name;
 384        struct regmap *regmap;
 385
 386        num_parents = of_clk_get_parent_count(np);
 387        if (num_parents == 0 || num_parents > USB_SOURCE_MAX)
 388                return;
 389
 390        of_clk_parent_fill(np, parent_names, num_parents);
 391
 392        of_property_read_string(np, "clock-output-names", &name);
 393
 394        regmap = syscon_node_to_regmap(of_get_parent(np));
 395        if (IS_ERR(regmap))
 396                return;
 397
 398        hw = at91sam9x5_clk_register_usb(regmap, name, parent_names,
 399                                         num_parents);
 400        if (IS_ERR(hw))
 401                return;
 402
 403        of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
 404}
 405CLK_OF_DECLARE(at91sam9x5_clk_usb, "atmel,at91sam9x5-clk-usb",
 406               of_at91sam9x5_clk_usb_setup);
 407
 408static void __init of_at91sam9n12_clk_usb_setup(struct device_node *np)
 409{
 410        struct clk_hw *hw;
 411        const char *parent_name;
 412        const char *name = np->name;
 413        struct regmap *regmap;
 414
 415        parent_name = of_clk_get_parent_name(np, 0);
 416        if (!parent_name)
 417                return;
 418
 419        of_property_read_string(np, "clock-output-names", &name);
 420
 421        regmap = syscon_node_to_regmap(of_get_parent(np));
 422        if (IS_ERR(regmap))
 423                return;
 424
 425        hw = at91sam9n12_clk_register_usb(regmap, name, parent_name);
 426        if (IS_ERR(hw))
 427                return;
 428
 429        of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
 430}
 431CLK_OF_DECLARE(at91sam9n12_clk_usb, "atmel,at91sam9n12-clk-usb",
 432               of_at91sam9n12_clk_usb_setup);
 433
 434static void __init of_at91rm9200_clk_usb_setup(struct device_node *np)
 435{
 436        struct clk_hw *hw;
 437        const char *parent_name;
 438        const char *name = np->name;
 439        u32 divisors[4] = {0, 0, 0, 0};
 440        struct regmap *regmap;
 441
 442        parent_name = of_clk_get_parent_name(np, 0);
 443        if (!parent_name)
 444                return;
 445
 446        of_property_read_u32_array(np, "atmel,clk-divisors", divisors, 4);
 447        if (!divisors[0])
 448                return;
 449
 450        of_property_read_string(np, "clock-output-names", &name);
 451
 452        regmap = syscon_node_to_regmap(of_get_parent(np));
 453        if (IS_ERR(regmap))
 454                return;
 455        hw = at91rm9200_clk_register_usb(regmap, name, parent_name, divisors);
 456        if (IS_ERR(hw))
 457                return;
 458
 459        of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
 460}
 461CLK_OF_DECLARE(at91rm9200_clk_usb, "atmel,at91rm9200-clk-usb",
 462               of_at91rm9200_clk_usb_setup);
 463