target/linux/ar7-2.6/files/arch/mips/ar7/clock.c

   1 /*
   2  * $Id$
   3  *
   4  * Copyright (C) 2007 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/init.h>
  22 #include <linux/types.h>
  23 #include <linux/module.h>
  24 #include <linux/delay.h>
  25 #include <asm/addrspace.h>
  26 #include <asm/io.h>
  27 #include <asm/ar7/ar7.h>
  28
  29 #define BOOT_PLL_SOURCE_MASK 0x3
  30 #define CPU_PLL_SOURCE_SHIFT 16
  31 #define BUS_PLL_SOURCE_SHIFT 14
  32 #define USB_PLL_SOURCE_SHIFT 18
  33 #define DSP_PLL_SOURCE_SHIFT 22
  34 #define BOOT_PLL_SOURCE_AFE 0
  35 #define BOOT_PLL_SOURCE_BUS 0
  36 #define BOOT_PLL_SOURCE_REF 1
  37 #define BOOT_PLL_SOURCE_XTAL 2
  38 #define BOOT_PLL_SOURCE_CPU 3
  39 #define BOOT_PLL_BYPASS 0x00000020
  40 #define BOOT_PLL_ASYNC_MODE 0x02000000
  41 #define BOOT_PLL_2TO1_MODE 0x00008000
  42
  43 struct tnetd7300_clock {
  44         volatile u32 ctrl;
  45 #define PREDIV_MASK 0x001f0000
  46 #define PREDIV_SHIFT 16
  47 #define POSTDIV_MASK 0x0000001f
  48         u32 unused1[3];
  49         volatile u32 pll;
  50 #define MUL_MASK 0x0000f000
  51 #define MUL_SHIFT 12
  52 #define PLL_MODE_MASK 0x00000001
  53 #define PLL_NDIV 0x00000800
  54 #define PLL_DIV 0x00000002
  55 #define PLL_STATUS 0x00000001
  56         u32 unused2[3];
  57 } __attribute__ ((packed));
  58
  59 struct tnetd7300_clocks {
  60         struct tnetd7300_clock bus;
  61         struct tnetd7300_clock cpu;
  62         struct tnetd7300_clock usb;
  63         struct tnetd7300_clock dsp;
  64 } __attribute__ ((packed));
  65
  66 struct tnetd7200_clock {
  67         volatile u32 ctrl;
  68         u32 unused1[3];
  69 #define DIVISOR_ENABLE_MASK 0x00008000
  70         volatile u32 mul;
  71         volatile u32 prediv;
  72         volatile u32 postdiv;
  73         u32 unused2[7];
  74         volatile u32 cmd;
  75         volatile u32 status;
  76         volatile u32 cmden;
  77         u32 padding[15];
  78 };
  79
  80 struct tnetd7200_clocks {
  81         struct tnetd7200_clock cpu;
  82         struct tnetd7200_clock dsp;
  83         struct tnetd7200_clock usb;
  84 };
  85
  86 int ar7_afe_clock = 35328000;
  87 int ar7_ref_clock = 25000000;
  88 int ar7_xtal_clock = 24000000;
  89
  90 int ar7_cpu_clock = 150000000;
  91 EXPORT_SYMBOL(ar7_cpu_clock);
  92 int ar7_bus_clock = 125000000;
  93 EXPORT_SYMBOL(ar7_bus_clock);
  94 int ar7_dsp_clock = 0;
  95 EXPORT_SYMBOL(ar7_dsp_clock);
  96
  97 static int gcd(int x, int y)
  98 {
  99         if (x > y)
 100                 return (x % y) ? gcd(y, x % y) : y;
 101         return (y % x) ? gcd(x, y % x) : x;
 102 }
 103
 104 static inline int ABS(int x)
 105 {
 106         return (x >= 0) ? x : -x;
 107 }
 108
 109 static void approximate(int base, int target, int *prediv,
 110                         int *postdiv, int *mul)
 111 {
 112         int i, j, k, freq, res = target;
 113         for (i = 1; i <= 16; i++) {
 114                 for (j = 1; j <= 32; j++) {
 115                         for (k = 1; k <= 32; k++) {
 116                                 freq = ABS(base / j * i / k - target);
 117                                 if (freq < res) {
 118                                         res = freq;
 119                                         *mul = i;
 120                                         *prediv = j;
 121                                         *postdiv = k;
 122                                 }
 123                         }
 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         int prediv = ((clock->ctrl & PREDIV_MASK) >> PREDIV_SHIFT) + 1;
 178         int postdiv = (clock->ctrl & POSTDIV_MASK) + 1;
 179         int divisor = prediv * postdiv;
 180         int mul = ((clock->pll & MUL_MASK) >> MUL_SHIFT) + 1;
 181
 182         switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
 183         case BOOT_PLL_SOURCE_BUS:
 184                 base_clock = bus_clock;
 185                 break;
 186         case BOOT_PLL_SOURCE_REF:
 187                 base_clock = ar7_ref_clock;
 188                 break;
 189         case BOOT_PLL_SOURCE_XTAL:
 190                 base_clock = ar7_xtal_clock;
 191                 break;
 192         case BOOT_PLL_SOURCE_CPU:
 193                 base_clock = ar7_cpu_clock;
 194                 break;
 195         }
 196
 197         if (*bootcr & BOOT_PLL_BYPASS)
 198                 return base_clock / divisor;
 199
 200         if ((clock->pll & PLL_MODE_MASK) == 0)
 201                 return (base_clock >> (mul / 16 + 1)) / divisor;
 202
 203         if ((clock->pll & (PLL_NDIV | PLL_DIV)) == (PLL_NDIV | PLL_DIV)) {
 204                 product = (mul & 1) ?
 205                         (base_clock * mul) >> 1 :
 206                         (base_clock * (mul - 1)) >> 2;
 207                 return product / divisor;
 208         }
 209
 210         if (mul == 16)
 211                 return base_clock / divisor;
 212
 213         return base_clock * mul / divisor;
 214 }
 215
 216 static void tnetd7300_set_clock(u32 shift, struct tnetd7300_clock *clock,
 217                                 u32 *bootcr, u32 frequency)
 218 {
 219         u32 status;
 220         int prediv, postdiv, mul;
 221         int base_clock = ar7_bus_clock;
 222
 223         switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
 224         case BOOT_PLL_SOURCE_BUS:
 225                 base_clock = ar7_bus_clock;
 226                 break;
 227         case BOOT_PLL_SOURCE_REF:
 228                 base_clock = ar7_ref_clock;
 229                 break;
 230         case BOOT_PLL_SOURCE_XTAL:
 231                 base_clock = ar7_xtal_clock;
 232                 break;
 233         case BOOT_PLL_SOURCE_CPU:
 234                 base_clock = ar7_cpu_clock;
 235                 break;
 236         }
 237
 238         calculate(base_clock, frequency, &prediv, &postdiv, &mul);
 239
 240         clock->ctrl = ((prediv - 1) << PREDIV_SHIFT) | (postdiv - 1);
 241         mdelay(1);
 242         clock->pll = 4;
 243         do {
 244                 status = clock->pll;
 245         } while (status & PLL_STATUS);
 246         clock->pll = ((mul - 1) << MUL_SHIFT) | (0xff << 3) | 0x0e;
 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 = (struct tnetd7300_clocks *)ioremap_nocache(AR7_REGS_POWER + 0x20, sizeof(struct tnetd7300_clocks));
 254
 255         ar7_bus_clock = tnetd7300_get_clock(BUS_PLL_SOURCE_SHIFT,
 256                                             &clocks->bus, bootcr,
 257                                             ar7_afe_clock);
 258
 259         if (*bootcr & BOOT_PLL_ASYNC_MODE) {
 260                 ar7_cpu_clock = tnetd7300_get_clock(CPU_PLL_SOURCE_SHIFT,
 261                                                     &clocks->cpu,
 262                                                     bootcr, ar7_afe_clock);
 263         } else {
 264                 ar7_cpu_clock = ar7_bus_clock;
 265         }
 266
 267         tnetd7300_set_clock(USB_PLL_SOURCE_SHIFT, &clocks->usb,
 268                             bootcr, 48000000);
 269
 270         if (ar7_dsp_clock == 250000000)
 271                 tnetd7300_set_clock(DSP_PLL_SOURCE_SHIFT, &clocks->dsp,
 272                                     bootcr, ar7_dsp_clock);
 273
 274         iounmap(clocks);
 275         iounmap(bootcr);
 276 }
 277
 278 static int tnetd7200_get_clock(int base, struct tnetd7200_clock *clock,
 279                                u32 *bootcr, u32 bus_clock)
 280 {
 281         int divisor = ((clock->prediv & 0x1f) + 1) *
 282                 ((clock->postdiv & 0x1f) + 1);
 283
 284         if (*bootcr & BOOT_PLL_BYPASS)
 285                 return base / divisor;
 286
 287         return base * ((clock->mul & 0xf) + 1) / divisor;
 288 }
 289
 290 static void tnetd7200_set_clock(int base, struct tnetd7200_clock *clock,
 291                                 u32 *bootcr, u32 frequency)
 292 {
 293         u32 status;
 294         int prediv, postdiv, mul;
 295
 296         calculate(base, frequency, &prediv, &postdiv, &mul);
 297
 298         clock->ctrl = 0;
 299         clock->prediv = DIVISOR_ENABLE_MASK | prediv;
 300         clock->mul = mul;
 301         mdelay(1);
 302         do {
 303                 status = clock->status;
 304         } while (status & PLL_STATUS);
 305         clock->postdiv = DIVISOR_ENABLE_MASK | postdiv;
 306         clock->cmden = 1;
 307         clock->cmd = 1;
 308         do {
 309                 status = clock->status;
 310         } while (status & PLL_STATUS);
 311         clock->ctrl = 1;
 312 }
 313
 314 static void __init tnetd7200_init_clocks(void)
 315 {
 316         u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
 317         struct tnetd7200_clocks *clocks = (struct tnetd7200_clocks *)ioremap_nocache(AR7_REGS_POWER + 0x80, sizeof(struct tnetd7200_clocks));
 318
 319         ar7_cpu_clock = tnetd7200_get_clock(ar7_afe_clock,
 320                                             &clocks->cpu,
 321                                             bootcr, ar7_afe_clock);
 322
 323         if (*bootcr & BOOT_PLL_ASYNC_MODE) {
 324                 ar7_bus_clock = 125000000;
 325         } else {
 326                 if (*bootcr & BOOT_PLL_2TO1_MODE) {
 327                         ar7_bus_clock = ar7_cpu_clock / 2;
 328                 } else {
 329                         ar7_bus_clock = ar7_cpu_clock;
 330                 }
 331         }
 332
 333         tnetd7200_set_clock(ar7_ref_clock * 5, &clocks->usb,
 334                             bootcr, 48000000);
 335
 336         if (ar7_dsp_clock == 250000000)
 337                 tnetd7200_set_clock(ar7_ref_clock, &clocks->dsp,
 338                                     bootcr, ar7_dsp_clock);
 339
 340         iounmap(clocks);
 341         iounmap(bootcr);
 342 }
 343
 344 void __init ar7_init_clocks(void)
 345 {
 346         switch (ar7_chip_id()) {
 347         case AR7_CHIP_7100:
 348                 tnetd7200_init_clocks();
 349                 break;
 350         case AR7_CHIP_7200:
 351 #warning FIXME: check revision
 352                 ar7_dsp_clock = 250000000;
 353                 tnetd7200_init_clocks();
 354                 break;
 355         case AR7_CHIP_7300:
 356                 ar7_dsp_clock = tnetd7300_dsp_clock();
 357                 tnetd7300_init_clocks();
 358                 break;
 359         default:
 360                 break;
 361         }
 362 }