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 struct at91sam9x5_clk_usb {
  27         struct clk_hw hw;
  28         struct regmap *regmap;
  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                         tmp_rate = DIV_ROUND_CLOSEST(tmp_parent_rate, div);
  80                         if (tmp_rate < req->rate)
  81                                 tmp_diff = req->rate - tmp_rate;
  82                         else
  83                                 tmp_diff = tmp_rate - req->rate;
  84
  85                         if (best_diff < 0 || best_diff > tmp_diff) {
  86                                 best_rate = tmp_rate;
  87                                 best_diff = tmp_diff;
  88                                 req->best_parent_rate = tmp_parent_rate;
  89                                 req->best_parent_hw = parent;
  90                         }
  91
  92                         if (!best_diff || tmp_rate < req->rate)
  93                                 break;
  94                 }
  95
  96                 if (!best_diff)
  97                         break;
  98         }
  99
 100         if (best_rate < 0)
 101                 return best_rate;
 102
 103         req->rate = best_rate;
 104         return 0;
 105 }
 106
 107 static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index)
 108 {
 109         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 110
 111         if (index > 1)
 112                 return -EINVAL;
 113
 114         regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_USBS,
 115                            index ? AT91_PMC_USBS : 0);
 116
 117         return 0;
 118 }
 119
 120 static u8 at91sam9x5_clk_usb_get_parent(struct clk_hw *hw)
 121 {
 122         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 123         unsigned int usbr;
 124
 125         regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
 126
 127         return usbr & AT91_PMC_USBS;
 128 }
 129
 130 static int at91sam9x5_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
 131                                        unsigned long parent_rate)
 132 {
 133         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 134         unsigned long div;
 135
 136         if (!rate)
 137                 return -EINVAL;
 138
 139         div = DIV_ROUND_CLOSEST(parent_rate, rate);
 140         if (div > SAM9X5_USB_MAX_DIV + 1 || !div)
 141                 return -EINVAL;
 142
 143         regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_OHCIUSBDIV,
 144                            (div - 1) << SAM9X5_USB_DIV_SHIFT);
 145
 146         return 0;
 147 }
 148
 149 static const struct clk_ops at91sam9x5_usb_ops = {
 150         .recalc_rate = at91sam9x5_clk_usb_recalc_rate,
 151         .determine_rate = at91sam9x5_clk_usb_determine_rate,
 152         .get_parent = at91sam9x5_clk_usb_get_parent,
 153         .set_parent = at91sam9x5_clk_usb_set_parent,
 154         .set_rate = at91sam9x5_clk_usb_set_rate,
 155 };
 156
 157 static int at91sam9n12_clk_usb_enable(struct clk_hw *hw)
 158 {
 159         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 160
 161         regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_USBS,
 162                            AT91_PMC_USBS);
 163
 164         return 0;
 165 }
 166
 167 static void at91sam9n12_clk_usb_disable(struct clk_hw *hw)
 168 {
 169         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 170
 171         regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_USBS, 0);
 172 }
 173
 174 static int at91sam9n12_clk_usb_is_enabled(struct clk_hw *hw)
 175 {
 176         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 177         unsigned int usbr;
 178
 179         regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
 180
 181         return usbr & AT91_PMC_USBS;
 182 }
 183
 184 static const struct clk_ops at91sam9n12_usb_ops = {
 185         .enable = at91sam9n12_clk_usb_enable,
 186         .disable = at91sam9n12_clk_usb_disable,
 187         .is_enabled = at91sam9n12_clk_usb_is_enabled,
 188         .recalc_rate = at91sam9x5_clk_usb_recalc_rate,
 189         .determine_rate = at91sam9x5_clk_usb_determine_rate,
 190         .set_rate = at91sam9x5_clk_usb_set_rate,
 191 };
 192
 193 struct clk_hw * __init
 194 at91sam9x5_clk_register_usb(struct regmap *regmap, const char *name,
 195                             const char **parent_names, u8 num_parents)
 196 {
 197         struct at91sam9x5_clk_usb *usb;
 198         struct clk_hw *hw;
 199         struct clk_init_data init;
 200         int ret;
 201
 202         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 203         if (!usb)
 204                 return ERR_PTR(-ENOMEM);
 205
 206         init.name = name;
 207         init.ops = &at91sam9x5_usb_ops;
 208         init.parent_names = parent_names;
 209         init.num_parents = num_parents;
 210         init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
 211                      CLK_SET_RATE_PARENT;
 212
 213         usb->hw.init = &init;
 214         usb->regmap = regmap;
 215
 216         hw = &usb->hw;
 217         ret = clk_hw_register(NULL, &usb->hw);
 218         if (ret) {
 219                 kfree(usb);
 220                 hw = ERR_PTR(ret);
 221         }
 222
 223         return hw;
 224 }
 225
 226 struct clk_hw * __init
 227 at91sam9n12_clk_register_usb(struct regmap *regmap, const char *name,
 228                              const char *parent_name)
 229 {
 230         struct at91sam9x5_clk_usb *usb;
 231         struct clk_hw *hw;
 232         struct clk_init_data init;
 233         int ret;
 234
 235         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 236         if (!usb)
 237                 return ERR_PTR(-ENOMEM);
 238
 239         init.name = name;
 240         init.ops = &at91sam9n12_usb_ops;
 241         init.parent_names = &parent_name;
 242         init.num_parents = 1;
 243         init.flags = CLK_SET_RATE_GATE | CLK_SET_RATE_PARENT;
 244
 245         usb->hw.init = &init;
 246         usb->regmap = regmap;
 247
 248         hw = &usb->hw;
 249         ret = clk_hw_register(NULL, &usb->hw);
 250         if (ret) {
 251                 kfree(usb);
 252                 hw = ERR_PTR(ret);
 253         }
 254
 255         return hw;
 256 }
 257
 258 static unsigned long at91rm9200_clk_usb_recalc_rate(struct clk_hw *hw,
 259                                                     unsigned long parent_rate)
 260 {
 261         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 262         unsigned int pllbr;
 263         u8 usbdiv;
 264
 265         regmap_read(usb->regmap, AT91_CKGR_PLLBR, &pllbr);
 266
 267         usbdiv = (pllbr & AT91_PMC_USBDIV) >> RM9200_USB_DIV_SHIFT;
 268         if (usb->divisors[usbdiv])
 269                 return parent_rate / usb->divisors[usbdiv];
 270
 271         return 0;
 272 }
 273
 274 static long at91rm9200_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
 275                                           unsigned long *parent_rate)
 276 {
 277         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 278         struct clk_hw *parent = clk_hw_get_parent(hw);
 279         unsigned long bestrate = 0;
 280         int bestdiff = -1;
 281         unsigned long tmprate;
 282         int tmpdiff;
 283         int i = 0;
 284
 285         for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
 286                 unsigned long tmp_parent_rate;
 287
 288                 if (!usb->divisors[i])
 289                         continue;
 290
 291                 tmp_parent_rate = rate * usb->divisors[i];
 292                 tmp_parent_rate = clk_hw_round_rate(parent, tmp_parent_rate);
 293                 tmprate = DIV_ROUND_CLOSEST(tmp_parent_rate, usb->divisors[i]);
 294                 if (tmprate < rate)
 295                         tmpdiff = rate - tmprate;
 296                 else
 297                         tmpdiff = tmprate - rate;
 298
 299                 if (bestdiff < 0 || bestdiff > tmpdiff) {
 300                         bestrate = tmprate;
 301                         bestdiff = tmpdiff;
 302                         *parent_rate = tmp_parent_rate;
 303                 }
 304
 305                 if (!bestdiff)
 306                         break;
 307         }
 308
 309         return bestrate;
 310 }
 311
 312 static int at91rm9200_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
 313                                        unsigned long parent_rate)
 314 {
 315         int i;
 316         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 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                         regmap_update_bits(usb->regmap, AT91_CKGR_PLLBR,
 327                                            AT91_PMC_USBDIV,
 328                                            i << RM9200_USB_DIV_SHIFT);
 329
 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 struct clk_hw * __init
 344 at91rm9200_clk_register_usb(struct regmap *regmap, const char *name,
 345                             const char *parent_name, const u32 *divisors)
 346 {
 347         struct at91rm9200_clk_usb *usb;
 348         struct clk_hw *hw;
 349         struct clk_init_data init;
 350         int ret;
 351
 352         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 353         if (!usb)
 354                 return ERR_PTR(-ENOMEM);
 355
 356         init.name = name;
 357         init.ops = &at91rm9200_usb_ops;
 358         init.parent_names = &parent_name;
 359         init.num_parents = 1;
 360         init.flags = CLK_SET_RATE_PARENT;
 361
 362         usb->hw.init = &init;
 363         usb->regmap = regmap;
 364         memcpy(usb->divisors, divisors, sizeof(usb->divisors));
 365
 366         hw = &usb->hw;
 367         ret = clk_hw_register(NULL, &usb->hw);
 368         if (ret) {
 369                 kfree(usb);
 370                 hw = ERR_PTR(ret);
 371         }
 372
 373         return hw;
 374 }