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         return parent_rate / (usbdiv + 1);
  56 }
  57
  58 static long at91sam9x5_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
  59                                           unsigned long *parent_rate)
  60 {
  61         unsigned long div;
  62         unsigned long bestrate;
  63         unsigned long tmp;
  64
  65         if (rate >= *parent_rate)
  66                 return *parent_rate;
  67
  68         div = *parent_rate / rate;
  69         if (div >= SAM9X5_USB_MAX_DIV)
  70                 return *parent_rate / (SAM9X5_USB_MAX_DIV + 1);
  71
  72         bestrate = *parent_rate / div;
  73         tmp = *parent_rate / (div + 1);
  74         if (bestrate - rate > rate - tmp)
  75                 bestrate = tmp;
  76
  77         return bestrate;
  78 }
  79
  80 static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index)
  81 {
  82         u32 tmp;
  83         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
  84         struct at91_pmc *pmc = usb->pmc;
  85
  86         if (index > 1)
  87                 return -EINVAL;
  88         tmp = pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_USBS;
  89         if (index)
  90                 tmp |= AT91_PMC_USBS;
  91         pmc_write(pmc, AT91_PMC_USB, tmp);
  92         return 0;
  93 }
  94
  95 static u8 at91sam9x5_clk_usb_get_parent(struct clk_hw *hw)
  96 {
  97         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
  98         struct at91_pmc *pmc = usb->pmc;
  99
 100         return pmc_read(pmc, AT91_PMC_USB) & AT91_PMC_USBS;
 101 }
 102
 103 static int at91sam9x5_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
 104                                        unsigned long parent_rate)
 105 {
 106         u32 tmp;
 107         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 108         struct at91_pmc *pmc = usb->pmc;
 109         unsigned long div = parent_rate / rate;
 110
 111         if (parent_rate % rate || div < 1 || div >= SAM9X5_USB_MAX_DIV)
 112                 return -EINVAL;
 113
 114         tmp = pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_OHCIUSBDIV;
 115         tmp |= (div - 1) << SAM9X5_USB_DIV_SHIFT;
 116         pmc_write(pmc, AT91_PMC_USB, tmp);
 117
 118         return 0;
 119 }
 120
 121 static const struct clk_ops at91sam9x5_usb_ops = {
 122         .recalc_rate = at91sam9x5_clk_usb_recalc_rate,
 123         .round_rate = at91sam9x5_clk_usb_round_rate,
 124         .get_parent = at91sam9x5_clk_usb_get_parent,
 125         .set_parent = at91sam9x5_clk_usb_set_parent,
 126         .set_rate = at91sam9x5_clk_usb_set_rate,
 127 };
 128
 129 static int at91sam9n12_clk_usb_enable(struct clk_hw *hw)
 130 {
 131         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 132         struct at91_pmc *pmc = usb->pmc;
 133
 134         pmc_write(pmc, AT91_PMC_USB,
 135                   pmc_read(pmc, AT91_PMC_USB) | AT91_PMC_USBS);
 136         return 0;
 137 }
 138
 139 static void at91sam9n12_clk_usb_disable(struct clk_hw *hw)
 140 {
 141         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 142         struct at91_pmc *pmc = usb->pmc;
 143
 144         pmc_write(pmc, AT91_PMC_USB,
 145                   pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_USBS);
 146 }
 147
 148 static int at91sam9n12_clk_usb_is_enabled(struct clk_hw *hw)
 149 {
 150         struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
 151         struct at91_pmc *pmc = usb->pmc;
 152
 153         return !!(pmc_read(pmc, AT91_PMC_USB) & AT91_PMC_USBS);
 154 }
 155
 156 static const struct clk_ops at91sam9n12_usb_ops = {
 157         .enable = at91sam9n12_clk_usb_enable,
 158         .disable = at91sam9n12_clk_usb_disable,
 159         .is_enabled = at91sam9n12_clk_usb_is_enabled,
 160         .recalc_rate = at91sam9x5_clk_usb_recalc_rate,
 161         .round_rate = at91sam9x5_clk_usb_round_rate,
 162         .set_rate = at91sam9x5_clk_usb_set_rate,
 163 };
 164
 165 static struct clk * __init
 166 at91sam9x5_clk_register_usb(struct at91_pmc *pmc, const char *name,
 167                             const char **parent_names, u8 num_parents)
 168 {
 169         struct at91sam9x5_clk_usb *usb;
 170         struct clk *clk = NULL;
 171         struct clk_init_data init;
 172
 173         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 174         if (!usb)
 175                 return ERR_PTR(-ENOMEM);
 176
 177         init.name = name;
 178         init.ops = &at91sam9x5_usb_ops;
 179         init.parent_names = parent_names;
 180         init.num_parents = num_parents;
 181         init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
 182
 183         usb->hw.init = &init;
 184         usb->pmc = pmc;
 185
 186         clk = clk_register(NULL, &usb->hw);
 187         if (IS_ERR(clk))
 188                 kfree(usb);
 189
 190         return clk;
 191 }
 192
 193 static struct clk * __init
 194 at91sam9n12_clk_register_usb(struct at91_pmc *pmc, const char *name,
 195                              const char *parent_name)
 196 {
 197         struct at91sam9x5_clk_usb *usb;
 198         struct clk *clk = NULL;
 199         struct clk_init_data init;
 200
 201         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 202         if (!usb)
 203                 return ERR_PTR(-ENOMEM);
 204
 205         init.name = name;
 206         init.ops = &at91sam9n12_usb_ops;
 207         init.parent_names = &parent_name;
 208         init.num_parents = 1;
 209         init.flags = CLK_SET_RATE_GATE;
 210
 211         usb->hw.init = &init;
 212         usb->pmc = pmc;
 213
 214         clk = clk_register(NULL, &usb->hw);
 215         if (IS_ERR(clk))
 216                 kfree(usb);
 217
 218         return clk;
 219 }
 220
 221 static unsigned long at91rm9200_clk_usb_recalc_rate(struct clk_hw *hw,
 222                                                     unsigned long parent_rate)
 223 {
 224         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 225         struct at91_pmc *pmc = usb->pmc;
 226         u32 tmp;
 227         u8 usbdiv;
 228
 229         tmp = pmc_read(pmc, AT91_CKGR_PLLBR);
 230         usbdiv = (tmp & AT91_PMC_USBDIV) >> RM9200_USB_DIV_SHIFT;
 231         if (usb->divisors[usbdiv])
 232                 return parent_rate / usb->divisors[usbdiv];
 233
 234         return 0;
 235 }
 236
 237 static long at91rm9200_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
 238                                           unsigned long *parent_rate)
 239 {
 240         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 241         struct clk *parent = __clk_get_parent(hw->clk);
 242         unsigned long bestrate = 0;
 243         int bestdiff = -1;
 244         unsigned long tmprate;
 245         int tmpdiff;
 246         int i = 0;
 247
 248         for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
 249                 unsigned long tmp_parent_rate;
 250
 251                 if (!usb->divisors[i])
 252                         continue;
 253
 254                 tmp_parent_rate = rate * usb->divisors[i];
 255                 tmp_parent_rate = __clk_round_rate(parent, tmp_parent_rate);
 256                 tmprate = tmp_parent_rate / usb->divisors[i];
 257                 if (tmprate < rate)
 258                         tmpdiff = rate - tmprate;
 259                 else
 260                         tmpdiff = tmprate - rate;
 261
 262                 if (bestdiff < 0 || bestdiff > tmpdiff) {
 263                         bestrate = tmprate;
 264                         bestdiff = tmpdiff;
 265                         *parent_rate = tmp_parent_rate;
 266                 }
 267
 268                 if (!bestdiff)
 269                         break;
 270         }
 271
 272         return bestrate;
 273 }
 274
 275 static int at91rm9200_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
 276                                        unsigned long parent_rate)
 277 {
 278         u32 tmp;
 279         int i;
 280         struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
 281         struct at91_pmc *pmc = usb->pmc;
 282         unsigned long div;
 283
 284         if (!rate || parent_rate % rate)
 285                 return -EINVAL;
 286
 287         div = parent_rate / rate;
 288
 289         for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
 290                 if (usb->divisors[i] == div) {
 291                         tmp = pmc_read(pmc, AT91_CKGR_PLLBR) &
 292                               ~AT91_PMC_USBDIV;
 293                         tmp |= i << RM9200_USB_DIV_SHIFT;
 294                         pmc_write(pmc, AT91_CKGR_PLLBR, tmp);
 295                         return 0;
 296                 }
 297         }
 298
 299         return -EINVAL;
 300 }
 301
 302 static const struct clk_ops at91rm9200_usb_ops = {
 303         .recalc_rate = at91rm9200_clk_usb_recalc_rate,
 304         .round_rate = at91rm9200_clk_usb_round_rate,
 305         .set_rate = at91rm9200_clk_usb_set_rate,
 306 };
 307
 308 static struct clk * __init
 309 at91rm9200_clk_register_usb(struct at91_pmc *pmc, const char *name,
 310                             const char *parent_name, const u32 *divisors)
 311 {
 312         struct at91rm9200_clk_usb *usb;
 313         struct clk *clk = NULL;
 314         struct clk_init_data init;
 315
 316         usb = kzalloc(sizeof(*usb), GFP_KERNEL);
 317         if (!usb)
 318                 return ERR_PTR(-ENOMEM);
 319
 320         init.name = name;
 321         init.ops = &at91rm9200_usb_ops;
 322         init.parent_names = &parent_name;
 323         init.num_parents = 1;
 324         init.flags = CLK_SET_RATE_PARENT;
 325
 326         usb->hw.init = &init;
 327         usb->pmc = pmc;
 328         memcpy(usb->divisors, divisors, sizeof(usb->divisors));
 329
 330         clk = clk_register(NULL, &usb->hw);
 331         if (IS_ERR(clk))
 332                 kfree(usb);
 333
 334         return clk;
 335 }
 336
 337 void __init of_at91sam9x5_clk_usb_setup(struct device_node *np,
 338                                         struct at91_pmc *pmc)
 339 {
 340         struct clk *clk;
 341         int i;
 342         int num_parents;
 343         const char *parent_names[USB_SOURCE_MAX];
 344         const char *name = np->name;
 345
 346         num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
 347         if (num_parents <= 0 || num_parents > USB_SOURCE_MAX)
 348                 return;
 349
 350         for (i = 0; i < num_parents; i++) {
 351                 parent_names[i] = of_clk_get_parent_name(np, i);
 352                 if (!parent_names[i])
 353                         return;
 354         }
 355
 356         of_property_read_string(np, "clock-output-names", &name);
 357
 358         clk = at91sam9x5_clk_register_usb(pmc, name, parent_names, num_parents);
 359         if (IS_ERR(clk))
 360                 return;
 361
 362         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 363 }
 364
 365 void __init of_at91sam9n12_clk_usb_setup(struct device_node *np,
 366                                          struct at91_pmc *pmc)
 367 {
 368         struct clk *clk;
 369         const char *parent_name;
 370         const char *name = np->name;
 371
 372         parent_name = of_clk_get_parent_name(np, 0);
 373         if (!parent_name)
 374                 return;
 375
 376         of_property_read_string(np, "clock-output-names", &name);
 377
 378         clk = at91sam9n12_clk_register_usb(pmc, name, parent_name);
 379         if (IS_ERR(clk))
 380                 return;
 381
 382         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 383 }
 384
 385 void __init of_at91rm9200_clk_usb_setup(struct device_node *np,
 386                                         struct at91_pmc *pmc)
 387 {
 388         struct clk *clk;
 389         const char *parent_name;
 390         const char *name = np->name;
 391         u32 divisors[4] = {0, 0, 0, 0};
 392
 393         parent_name = of_clk_get_parent_name(np, 0);
 394         if (!parent_name)
 395                 return;
 396
 397         of_property_read_u32_array(np, "atmel,clk-divisors", divisors, 4);
 398         if (!divisors[0])
 399                 return;
 400
 401         of_property_read_string(np, "clock-output-names", &name);
 402
 403         clk = at91rm9200_clk_register_usb(pmc, name, parent_name, divisors);
 404         if (IS_ERR(clk))
 405                 return;
 406
 407         of_clk_add_provider(np, of_clk_src_simple_get, clk);
 408 }