arch/mips/ar7/clock.c

   1 /*
   2  * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
   3  * Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
   4  * Copyright (C) 2009 Florian Fainelli <florian@openwrt.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  */
  20
  21 #include <linux/kernel.h>
  22 #include <linux/init.h>
  23 #include <linux/types.h>
  24 #include <linux/module.h>
  25 #include <linux/delay.h>
  26 #include <linux/gcd.h>
  27 #include <linux/io.h>
  28 #include <linux/err.h>
  29 #include <linux/clk.h>
  30
  31 #include <asm/addrspace.h>
  32 #include <asm/mach-ar7/ar7.h>
  33
  34 #define BOOT_PLL_SOURCE_MASK    0x3
  35 #define CPU_PLL_SOURCE_SHIFT    16
  36 #define BUS_PLL_SOURCE_SHIFT    14
  37 #define USB_PLL_SOURCE_SHIFT    18
  38 #define DSP_PLL_SOURCE_SHIFT    22
  39 #define BOOT_PLL_SOURCE_AFE     0
  40 #define BOOT_PLL_SOURCE_BUS     0
  41 #define BOOT_PLL_SOURCE_REF     1
  42 #define BOOT_PLL_SOURCE_XTAL    2
  43 #define BOOT_PLL_SOURCE_CPU     3
  44 #define BOOT_PLL_BYPASS         0x00000020
  45 #define BOOT_PLL_ASYNC_MODE     0x02000000
  46 #define BOOT_PLL_2TO1_MODE      0x00008000
  47
  48 #define TNETD7200_CLOCK_ID_CPU  0
  49 #define TNETD7200_CLOCK_ID_DSP  1
  50 #define TNETD7200_CLOCK_ID_USB  2
  51
  52 #define TNETD7200_DEF_CPU_CLK   211000000
  53 #define TNETD7200_DEF_DSP_CLK   125000000
  54 #define TNETD7200_DEF_USB_CLK   48000000
  55
  56 struct tnetd7300_clock {
  57         u32 ctrl;
  58 #define PREDIV_MASK     0x001f0000
  59 #define PREDIV_SHIFT    16
  60 #define POSTDIV_MASK    0x0000001f
  61         u32 unused1[3];
  62         u32 pll;
  63 #define MUL_MASK        0x0000f000
  64 #define MUL_SHIFT       12
  65 #define PLL_MODE_MASK   0x00000001
  66 #define PLL_NDIV        0x00000800
  67 #define PLL_DIV         0x00000002
  68 #define PLL_STATUS      0x00000001
  69         u32 unused2[3];
  70 };
  71
  72 struct tnetd7300_clocks {
  73         struct tnetd7300_clock bus;
  74         struct tnetd7300_clock cpu;
  75         struct tnetd7300_clock usb;
  76         struct tnetd7300_clock dsp;
  77 };
  78
  79 struct tnetd7200_clock {
  80         u32 ctrl;
  81         u32 unused1[3];
  82 #define DIVISOR_ENABLE_MASK 0x00008000
  83         u32 mul;
  84         u32 prediv;
  85         u32 postdiv;
  86         u32 postdiv2;
  87         u32 unused2[6];
  88         u32 cmd;
  89         u32 status;
  90         u32 cmden;
  91         u32 padding[15];
  92 };
  93
  94 struct tnetd7200_clocks {
  95         struct tnetd7200_clock cpu;
  96         struct tnetd7200_clock dsp;
  97         struct tnetd7200_clock usb;
  98 };
  99
 100 static struct clk bus_clk = {
 101         .rate   = 125000000,
 102 };
 103
 104 static struct clk cpu_clk = {
 105         .rate   = 150000000,
 106 };
 107
 108 static struct clk dsp_clk;
 109 static struct clk vbus_clk;
 110
 111 static void approximate(int base, int target, int *prediv,
 112                         int *postdiv, int *mul)
 113 {
 114         int i, j, k, freq, res = target;
 115         for (i = 1; i <= 16; i++)
 116                 for (j = 1; j <= 32; j++)
 117                         for (k = 1; k <= 32; k++) {
 118                                 freq = abs(base / j * i / k - target);
 119                                 if (freq < res) {
 120                                         res = freq;
 121                                         *mul = i;
 122                                         *prediv = j;
 123                                         *postdiv = k;
 124                                 }
 125                         }
 126 }
 127
 128 static void calculate(int base, int target, int *prediv, int *postdiv,
 129         int *mul)
 130 {
 131         int tmp_gcd, tmp_base, tmp_freq;
 132
 133         for (*prediv = 1; *prediv <= 32; (*prediv)++) {
 134                 tmp_base = base / *prediv;
 135                 tmp_gcd = gcd(target, tmp_base);
 136                 *mul = target / tmp_gcd;
 137                 *postdiv = tmp_base / tmp_gcd;
 138                 if ((*mul < 1) || (*mul >= 16))
 139                         continue;
 140                 if ((*postdiv > 0) & (*postdiv <= 32))
 141                         break;
 142         }
 143
 144         if (base / *prediv * *mul / *postdiv != target) {
 145                 approximate(base, target, prediv, postdiv, mul);
 146                 tmp_freq = base / *prediv * *mul / *postdiv;
 147                 printk(KERN_WARNING
 148                        "Adjusted requested frequency %d to %d\n",
 149                        target, tmp_freq);
 150         }
 151
 152         printk(KERN_DEBUG "Clocks: prediv: %d, postdiv: %d, mul: %d\n",
 153                *prediv, *postdiv, *mul);
 154 }
 155
 156 static int tnetd7300_dsp_clock(void)
 157 {
 158         u32 didr1, didr2;
 159         u8 rev = ar7_chip_rev();
 160         didr1 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x18));
 161         didr2 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x1c));
 162         if (didr2 & (1 << 23))
 163                 return 0;
 164         if ((rev >= 0x23) && (rev != 0x57))
 165                 return 250000000;
 166         if ((((didr2 & 0x1fff) << 10) | ((didr1 & 0xffc00000) >> 22))
 167             > 4208000)
 168                 return 250000000;
 169         return 0;
 170 }
 171
 172 static int tnetd7300_get_clock(u32 shift, struct tnetd7300_clock *clock,
 173         u32 *bootcr, u32 bus_clock)
 174 {
 175         int product;
 176         int base_clock = AR7_REF_CLOCK;
 177         u32 ctrl = readl(&clock->ctrl);
 178         u32 pll = readl(&clock->pll);
 179         int prediv = ((ctrl & PREDIV_MASK) >> PREDIV_SHIFT) + 1;
 180         int postdiv = (ctrl & POSTDIV_MASK) + 1;
 181         int divisor = prediv * postdiv;
 182         int mul = ((pll & MUL_MASK) >> MUL_SHIFT) + 1;
 183
 184         switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
 185         case BOOT_PLL_SOURCE_BUS:
 186                 base_clock = bus_clock;
 187                 break;
 188         case BOOT_PLL_SOURCE_REF:
 189                 base_clock = AR7_REF_CLOCK;
 190                 break;
 191         case BOOT_PLL_SOURCE_XTAL:
 192                 base_clock = AR7_XTAL_CLOCK;
 193                 break;
 194         case BOOT_PLL_SOURCE_CPU:
 195                 base_clock = cpu_clk.rate;
 196                 break;
 197         }
 198
 199         if (*bootcr & BOOT_PLL_BYPASS)
 200                 return base_clock / divisor;
 201
 202         if ((pll & PLL_MODE_MASK) == 0)
 203                 return (base_clock >> (mul / 16 + 1)) / divisor;
 204
 205         if ((pll & (PLL_NDIV | PLL_DIV)) == (PLL_NDIV | PLL_DIV)) {
 206                 product = (mul & 1) ?
 207                         (base_clock * mul) >> 1 :
 208                         (base_clock * (mul - 1)) >> 2;
 209                 return product / divisor;
 210         }
 211
 212         if (mul == 16)
 213                 return base_clock / divisor;
 214
 215         return base_clock * mul / divisor;
 216 }
 217
 218 static void tnetd7300_set_clock(u32 shift, struct tnetd7300_clock *clock,
 219         u32 *bootcr, u32 frequency)
 220 {
 221         int prediv, postdiv, mul;
 222         int base_clock = bus_clk.rate;
 223
 224         switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
 225         case BOOT_PLL_SOURCE_BUS:
 226                 base_clock = bus_clk.rate;
 227                 break;
 228         case BOOT_PLL_SOURCE_REF:
 229                 base_clock = AR7_REF_CLOCK;
 230                 break;
 231         case BOOT_PLL_SOURCE_XTAL:
 232                 base_clock = AR7_XTAL_CLOCK;
 233                 break;
 234         case BOOT_PLL_SOURCE_CPU:
 235                 base_clock = cpu_clk.rate;
 236                 break;
 237         }
 238
 239         calculate(base_clock, frequency, &prediv, &postdiv, &mul);
 240
 241         writel(((prediv - 1) << PREDIV_SHIFT) | (postdiv - 1), &clock->ctrl);
 242         mdelay(1);
 243         writel(4, &clock->pll);
 244         while (readl(&clock->pll) & PLL_STATUS)
 245                 ;
 246         writel(((mul - 1) << MUL_SHIFT) | (0xff << 3) | 0x0e, &clock->pll);
 247         mdelay(75);
 248 }
 249
 250 static void __init tnetd7300_init_clocks(void)
 251 {
 252         u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
 253         struct tnetd7300_clocks *clocks =
 254                                         ioremap_nocache(UR8_REGS_CLOCKS,
 255                                         sizeof(struct tnetd7300_clocks));
 256
 257         bus_clk.rate = tnetd7300_get_clock(BUS_PLL_SOURCE_SHIFT,
 258                 &clocks->bus, bootcr, AR7_AFE_CLOCK);
 259
 260         if (*bootcr & BOOT_PLL_ASYNC_MODE)
 261                 cpu_clk.rate = tnetd7300_get_clock(CPU_PLL_SOURCE_SHIFT,
 262                         &clocks->cpu, bootcr, AR7_AFE_CLOCK);
 263         else
 264                 cpu_clk.rate = bus_clk.rate;
 265
 266         if (dsp_clk.rate == 250000000)
 267                 tnetd7300_set_clock(DSP_PLL_SOURCE_SHIFT, &clocks->dsp,
 268                         bootcr, dsp_clk.rate);
 269
 270         iounmap(clocks);
 271         iounmap(bootcr);
 272 }
 273
 274 static void tnetd7200_set_clock(int base, struct tnetd7200_clock *clock,
 275         int prediv, int postdiv, int postdiv2, int mul, u32 frequency)
 276 {
 277         printk(KERN_INFO
 278                 "Clocks: base = %d, frequency = %u, prediv = %d, "
 279                 "postdiv = %d, postdiv2 = %d, mul = %d\n",
 280                 base, frequency, prediv, postdiv, postdiv2, mul);
 281
 282         writel(0, &clock->ctrl);
 283         writel(DIVISOR_ENABLE_MASK | ((prediv - 1) & 0x1F), &clock->prediv);
 284         writel((mul - 1) & 0xF, &clock->mul);
 285
 286         while (readl(&clock->status) & 0x1)
 287                 ; /* nop */
 288
 289         writel(DIVISOR_ENABLE_MASK | ((postdiv - 1) & 0x1F), &clock->postdiv);
 290
 291         writel(readl(&clock->cmden) | 1, &clock->cmden);
 292         writel(readl(&clock->cmd) | 1, &clock->cmd);
 293
 294         while (readl(&clock->status) & 0x1)
 295                 ; /* nop */
 296
 297         writel(DIVISOR_ENABLE_MASK | ((postdiv2 - 1) & 0x1F), &clock->postdiv2);
 298
 299         writel(readl(&clock->cmden) | 1, &clock->cmden);
 300         writel(readl(&clock->cmd) | 1, &clock->cmd);
 301
 302         while (readl(&clock->status) & 0x1)
 303                 ; /* nop */
 304
 305         writel(readl(&clock->ctrl) | 1, &clock->ctrl);
 306 }
 307
 308 static int tnetd7200_get_clock_base(int clock_id, u32 *bootcr)
 309 {
 310         if (*bootcr & BOOT_PLL_ASYNC_MODE)
 311                 /* Async */
 312                 switch (clock_id) {
 313                 case TNETD7200_CLOCK_ID_DSP:
 314                         return AR7_REF_CLOCK;
 315                 default:
 316                         return AR7_AFE_CLOCK;
 317                 }
 318         else
 319                 /* Sync */
 320                 if (*bootcr & BOOT_PLL_2TO1_MODE)
 321                         /* 2:1 */
 322                         switch (clock_id) {
 323                         case TNETD7200_CLOCK_ID_DSP:
 324                                 return AR7_REF_CLOCK;
 325                         default:
 326                                 return AR7_AFE_CLOCK;
 327                         }
 328                 else
 329                         /* 1:1 */
 330                         return AR7_REF_CLOCK;
 331 }
 332
 333
 334 static void __init tnetd7200_init_clocks(void)
 335 {
 336         u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
 337         struct tnetd7200_clocks *clocks =
 338                                         ioremap_nocache(AR7_REGS_CLOCKS,
 339                                         sizeof(struct tnetd7200_clocks));
 340         int cpu_base, cpu_mul, cpu_prediv, cpu_postdiv;
 341         int dsp_base, dsp_mul, dsp_prediv, dsp_postdiv;
 342         int usb_base, usb_mul, usb_prediv, usb_postdiv;
 343
 344         cpu_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_CPU, bootcr);
 345         dsp_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_DSP, bootcr);
 346
 347         if (*bootcr & BOOT_PLL_ASYNC_MODE) {
 348                 printk(KERN_INFO "Clocks: Async mode\n");
 349
 350                 printk(KERN_INFO "Clocks: Setting DSP clock\n");
 351                 calculate(dsp_base, TNETD7200_DEF_DSP_CLK,
 352                         &dsp_prediv, &dsp_postdiv, &dsp_mul);
 353                 bus_clk.rate =
 354                         ((dsp_base / dsp_prediv) * dsp_mul) / dsp_postdiv;
 355                 tnetd7200_set_clock(dsp_base, &clocks->dsp,
 356                         dsp_prediv, dsp_postdiv * 2, dsp_postdiv, dsp_mul * 2,
 357                         bus_clk.rate);
 358
 359                 printk(KERN_INFO "Clocks: Setting CPU clock\n");
 360                 calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
 361                         &cpu_postdiv, &cpu_mul);
 362                 cpu_clk.rate =
 363                         ((cpu_base / cpu_prediv) * cpu_mul) / cpu_postdiv;
 364                 tnetd7200_set_clock(cpu_base, &clocks->cpu,
 365                         cpu_prediv, cpu_postdiv, -1, cpu_mul,
 366                         cpu_clk.rate);
 367
 368         } else
 369                 if (*bootcr & BOOT_PLL_2TO1_MODE) {
 370                         printk(KERN_INFO "Clocks: Sync 2:1 mode\n");
 371
 372                         printk(KERN_INFO "Clocks: Setting CPU clock\n");
 373                         calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
 374                                 &cpu_postdiv, &cpu_mul);
 375                         cpu_clk.rate = ((cpu_base / cpu_prediv) * cpu_mul)
 376                                                                 / cpu_postdiv;
 377                         tnetd7200_set_clock(cpu_base, &clocks->cpu,
 378                                 cpu_prediv, cpu_postdiv, -1, cpu_mul,
 379                                 cpu_clk.rate);
 380
 381                         printk(KERN_INFO "Clocks: Setting DSP clock\n");
 382                         calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
 383                                 &dsp_postdiv, &dsp_mul);
 384                         bus_clk.rate = cpu_clk.rate / 2;
 385                         tnetd7200_set_clock(dsp_base, &clocks->dsp,
 386                                 dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
 387                                 dsp_mul * 2, bus_clk.rate);
 388                 } else {
 389                         printk(KERN_INFO "Clocks: Sync 1:1 mode\n");
 390
 391                         printk(KERN_INFO "Clocks: Setting DSP clock\n");
 392                         calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
 393                                 &dsp_postdiv, &dsp_mul);
 394                         bus_clk.rate = ((dsp_base / dsp_prediv) * dsp_mul)
 395                                                                 / dsp_postdiv;
 396                         tnetd7200_set_clock(dsp_base, &clocks->dsp,
 397                                 dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
 398                                 dsp_mul * 2, bus_clk.rate);
 399
 400                         cpu_clk.rate = bus_clk.rate;
 401                 }
 402
 403         printk(KERN_INFO "Clocks: Setting USB clock\n");
 404         usb_base = bus_clk.rate;
 405         calculate(usb_base, TNETD7200_DEF_USB_CLK, &usb_prediv,
 406                 &usb_postdiv, &usb_mul);
 407         tnetd7200_set_clock(usb_base, &clocks->usb,
 408                 usb_prediv, usb_postdiv, -1, usb_mul,
 409                 TNETD7200_DEF_USB_CLK);
 410
 411         dsp_clk.rate = cpu_clk.rate;
 412
 413         iounmap(clocks);
 414         iounmap(bootcr);
 415 }
 416
 417 /*
 418  * Linux clock API
 419  */
 420 int clk_enable(struct clk *clk)
 421 {
 422         return 0;
 423 }
 424 EXPORT_SYMBOL(clk_enable);
 425
 426 void clk_disable(struct clk *clk)
 427 {
 428 }
 429 EXPORT_SYMBOL(clk_disable);
 430
 431 unsigned long clk_get_rate(struct clk *clk)
 432 {
 433         return clk->rate;
 434 }
 435 EXPORT_SYMBOL(clk_get_rate);
 436
 437 struct clk *clk_get(struct device *dev, const char *id)
 438 {
 439         if (!strcmp(id, "bus"))
 440                 return &bus_clk;
 441         /* cpmac and vbus share the same rate */
 442         if (!strcmp(id, "cpmac"))
 443                 return &vbus_clk;
 444         if (!strcmp(id, "cpu"))
 445                 return &cpu_clk;
 446         if (!strcmp(id, "dsp"))
 447                 return &dsp_clk;
 448         if (!strcmp(id, "vbus"))
 449                 return &vbus_clk;
 450         return ERR_PTR(-ENOENT);
 451 }
 452 EXPORT_SYMBOL(clk_get);
 453
 454 void clk_put(struct clk *clk)
 455 {
 456 }
 457 EXPORT_SYMBOL(clk_put);
 458
 459 void __init ar7_init_clocks(void)
 460 {
 461         switch (ar7_chip_id()) {
 462         case AR7_CHIP_7100:
 463         case AR7_CHIP_7200:
 464                 tnetd7200_init_clocks();
 465                 break;
 466         case AR7_CHIP_7300:
 467                 dsp_clk.rate = tnetd7300_dsp_clock();
 468                 tnetd7300_init_clocks();
 469                 break;
 470         default:
 471                 break;
 472         }
 473         /* adjust vbus clock rate */
 474         vbus_clk.rate = bus_clk.rate / 2;
 475 }