linux/arch/mips/ar7/clock.c
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   1/*
   2 * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
   3 * Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License as published by
   7 * the Free Software Foundation; either version 2 of the License, or
   8 * (at your option) any later version.
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 * GNU General Public License for more details.
  14 *
  15 * You should have received a copy of the GNU General Public License
  16 * along with this program; if not, write to the Free Software
  17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18 */
  19
  20#include <linux/kernel.h>
  21#include <linux/init.h>
  22#include <linux/types.h>
  23#include <linux/module.h>
  24#include <linux/delay.h>
  25#include <linux/gcd.h>
  26#include <linux/io.h>
  27
  28#include <asm/addrspace.h>
  29#include <asm/mach-ar7/ar7.h>
  30
  31#define BOOT_PLL_SOURCE_MASK    0x3
  32#define CPU_PLL_SOURCE_SHIFT    16
  33#define BUS_PLL_SOURCE_SHIFT    14
  34#define USB_PLL_SOURCE_SHIFT    18
  35#define DSP_PLL_SOURCE_SHIFT    22
  36#define BOOT_PLL_SOURCE_AFE     0
  37#define BOOT_PLL_SOURCE_BUS     0
  38#define BOOT_PLL_SOURCE_REF     1
  39#define BOOT_PLL_SOURCE_XTAL    2
  40#define BOOT_PLL_SOURCE_CPU     3
  41#define BOOT_PLL_BYPASS         0x00000020
  42#define BOOT_PLL_ASYNC_MODE     0x02000000
  43#define BOOT_PLL_2TO1_MODE      0x00008000
  44
  45#define TNETD7200_CLOCK_ID_CPU  0
  46#define TNETD7200_CLOCK_ID_DSP  1
  47#define TNETD7200_CLOCK_ID_USB  2
  48
  49#define TNETD7200_DEF_CPU_CLK   211000000
  50#define TNETD7200_DEF_DSP_CLK   125000000
  51#define TNETD7200_DEF_USB_CLK   48000000
  52
  53struct tnetd7300_clock {
  54        u32 ctrl;
  55#define PREDIV_MASK     0x001f0000
  56#define PREDIV_SHIFT    16
  57#define POSTDIV_MASK    0x0000001f
  58        u32 unused1[3];
  59        u32 pll;
  60#define MUL_MASK        0x0000f000
  61#define MUL_SHIFT       12
  62#define PLL_MODE_MASK   0x00000001
  63#define PLL_NDIV        0x00000800
  64#define PLL_DIV         0x00000002
  65#define PLL_STATUS      0x00000001
  66        u32 unused2[3];
  67};
  68
  69struct tnetd7300_clocks {
  70        struct tnetd7300_clock bus;
  71        struct tnetd7300_clock cpu;
  72        struct tnetd7300_clock usb;
  73        struct tnetd7300_clock dsp;
  74};
  75
  76struct tnetd7200_clock {
  77        u32 ctrl;
  78        u32 unused1[3];
  79#define DIVISOR_ENABLE_MASK 0x00008000
  80        u32 mul;
  81        u32 prediv;
  82        u32 postdiv;
  83        u32 postdiv2;
  84        u32 unused2[6];
  85        u32 cmd;
  86        u32 status;
  87        u32 cmden;
  88        u32 padding[15];
  89};
  90
  91struct tnetd7200_clocks {
  92        struct tnetd7200_clock cpu;
  93        struct tnetd7200_clock dsp;
  94        struct tnetd7200_clock usb;
  95};
  96
  97int ar7_cpu_clock = 150000000;
  98EXPORT_SYMBOL(ar7_cpu_clock);
  99int ar7_bus_clock = 125000000;
 100EXPORT_SYMBOL(ar7_bus_clock);
 101int ar7_dsp_clock;
 102EXPORT_SYMBOL(ar7_dsp_clock);
 103
 104static void approximate(int base, int target, int *prediv,
 105                        int *postdiv, int *mul)
 106{
 107        int i, j, k, freq, res = target;
 108        for (i = 1; i <= 16; i++)
 109                for (j = 1; j <= 32; j++)
 110                        for (k = 1; k <= 32; k++) {
 111                                freq = abs(base / j * i / k - target);
 112                                if (freq < res) {
 113                                        res = freq;
 114                                        *mul = i;
 115                                        *prediv = j;
 116                                        *postdiv = k;
 117                                }
 118                        }
 119}
 120
 121static void calculate(int base, int target, int *prediv, int *postdiv,
 122        int *mul)
 123{
 124        int tmp_gcd, tmp_base, tmp_freq;
 125
 126        for (*prediv = 1; *prediv <= 32; (*prediv)++) {
 127                tmp_base = base / *prediv;
 128                tmp_gcd = gcd(target, tmp_base);
 129                *mul = target / tmp_gcd;
 130                *postdiv = tmp_base / tmp_gcd;
 131                if ((*mul < 1) || (*mul >= 16))
 132                        continue;
 133                if ((*postdiv > 0) & (*postdiv <= 32))
 134                        break;
 135        }
 136
 137        if (base / *prediv * *mul / *postdiv != target) {
 138                approximate(base, target, prediv, postdiv, mul);
 139                tmp_freq = base / *prediv * *mul / *postdiv;
 140                printk(KERN_WARNING
 141                       "Adjusted requested frequency %d to %d\n",
 142                       target, tmp_freq);
 143        }
 144
 145        printk(KERN_DEBUG "Clocks: prediv: %d, postdiv: %d, mul: %d\n",
 146               *prediv, *postdiv, *mul);
 147}
 148
 149static int tnetd7300_dsp_clock(void)
 150{
 151        u32 didr1, didr2;
 152        u8 rev = ar7_chip_rev();
 153        didr1 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x18));
 154        didr2 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x1c));
 155        if (didr2 & (1 << 23))
 156                return 0;
 157        if ((rev >= 0x23) && (rev != 0x57))
 158                return 250000000;
 159        if ((((didr2 & 0x1fff) << 10) | ((didr1 & 0xffc00000) >> 22))
 160            > 4208000)
 161                return 250000000;
 162        return 0;
 163}
 164
 165static int tnetd7300_get_clock(u32 shift, struct tnetd7300_clock *clock,
 166        u32 *bootcr, u32 bus_clock)
 167{
 168        int product;
 169        int base_clock = AR7_REF_CLOCK;
 170        u32 ctrl = readl(&clock->ctrl);
 171        u32 pll = readl(&clock->pll);
 172        int prediv = ((ctrl & PREDIV_MASK) >> PREDIV_SHIFT) + 1;
 173        int postdiv = (ctrl & POSTDIV_MASK) + 1;
 174        int divisor = prediv * postdiv;
 175        int mul = ((pll & MUL_MASK) >> MUL_SHIFT) + 1;
 176
 177        switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
 178        case BOOT_PLL_SOURCE_BUS:
 179                base_clock = bus_clock;
 180                break;
 181        case BOOT_PLL_SOURCE_REF:
 182                base_clock = AR7_REF_CLOCK;
 183                break;
 184        case BOOT_PLL_SOURCE_XTAL:
 185                base_clock = AR7_XTAL_CLOCK;
 186                break;
 187        case BOOT_PLL_SOURCE_CPU:
 188                base_clock = ar7_cpu_clock;
 189                break;
 190        }
 191
 192        if (*bootcr & BOOT_PLL_BYPASS)
 193                return base_clock / divisor;
 194
 195        if ((pll & PLL_MODE_MASK) == 0)
 196                return (base_clock >> (mul / 16 + 1)) / divisor;
 197
 198        if ((pll & (PLL_NDIV | PLL_DIV)) == (PLL_NDIV | PLL_DIV)) {
 199                product = (mul & 1) ?
 200                        (base_clock * mul) >> 1 :
 201                        (base_clock * (mul - 1)) >> 2;
 202                return product / divisor;
 203        }
 204
 205        if (mul == 16)
 206                return base_clock / divisor;
 207
 208        return base_clock * mul / divisor;
 209}
 210
 211static void tnetd7300_set_clock(u32 shift, struct tnetd7300_clock *clock,
 212        u32 *bootcr, u32 frequency)
 213{
 214        int prediv, postdiv, mul;
 215        int base_clock = ar7_bus_clock;
 216
 217        switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
 218        case BOOT_PLL_SOURCE_BUS:
 219                base_clock = ar7_bus_clock;
 220                break;
 221        case BOOT_PLL_SOURCE_REF:
 222                base_clock = AR7_REF_CLOCK;
 223                break;
 224        case BOOT_PLL_SOURCE_XTAL:
 225                base_clock = AR7_XTAL_CLOCK;
 226                break;
 227        case BOOT_PLL_SOURCE_CPU:
 228                base_clock = ar7_cpu_clock;
 229                break;
 230        }
 231
 232        calculate(base_clock, frequency, &prediv, &postdiv, &mul);
 233
 234        writel(((prediv - 1) << PREDIV_SHIFT) | (postdiv - 1), &clock->ctrl);
 235        msleep(1);
 236        writel(4, &clock->pll);
 237        while (readl(&clock->pll) & PLL_STATUS)
 238                ;
 239        writel(((mul - 1) << MUL_SHIFT) | (0xff << 3) | 0x0e, &clock->pll);
 240        msleep(75);
 241}
 242
 243static void __init tnetd7300_init_clocks(void)
 244{
 245        u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
 246        struct tnetd7300_clocks *clocks =
 247                                        ioremap_nocache(UR8_REGS_CLOCKS,
 248                                        sizeof(struct tnetd7300_clocks));
 249
 250        ar7_bus_clock = tnetd7300_get_clock(BUS_PLL_SOURCE_SHIFT,
 251                &clocks->bus, bootcr, AR7_AFE_CLOCK);
 252
 253        if (*bootcr & BOOT_PLL_ASYNC_MODE)
 254                ar7_cpu_clock = tnetd7300_get_clock(CPU_PLL_SOURCE_SHIFT,
 255                        &clocks->cpu, bootcr, AR7_AFE_CLOCK);
 256        else
 257                ar7_cpu_clock = ar7_bus_clock;
 258
 259        if (ar7_dsp_clock == 250000000)
 260                tnetd7300_set_clock(DSP_PLL_SOURCE_SHIFT, &clocks->dsp,
 261                        bootcr, ar7_dsp_clock);
 262
 263        iounmap(clocks);
 264        iounmap(bootcr);
 265}
 266
 267static void tnetd7200_set_clock(int base, struct tnetd7200_clock *clock,
 268        int prediv, int postdiv, int postdiv2, int mul, u32 frequency)
 269{
 270        printk(KERN_INFO
 271                "Clocks: base = %d, frequency = %u, prediv = %d, "
 272                "postdiv = %d, postdiv2 = %d, mul = %d\n",
 273                base, frequency, prediv, postdiv, postdiv2, mul);
 274
 275        writel(0, &clock->ctrl);
 276        writel(DIVISOR_ENABLE_MASK | ((prediv - 1) & 0x1F), &clock->prediv);
 277        writel((mul - 1) & 0xF, &clock->mul);
 278
 279        while (readl(&clock->status) & 0x1)
 280                ; /* nop */
 281
 282        writel(DIVISOR_ENABLE_MASK | ((postdiv - 1) & 0x1F), &clock->postdiv);
 283
 284        writel(readl(&clock->cmden) | 1, &clock->cmden);
 285        writel(readl(&clock->cmd) | 1, &clock->cmd);
 286
 287        while (readl(&clock->status) & 0x1)
 288                ; /* nop */
 289
 290        writel(DIVISOR_ENABLE_MASK | ((postdiv2 - 1) & 0x1F), &clock->postdiv2);
 291
 292        writel(readl(&clock->cmden) | 1, &clock->cmden);
 293        writel(readl(&clock->cmd) | 1, &clock->cmd);
 294
 295        while (readl(&clock->status) & 0x1)
 296                ; /* nop */
 297
 298        writel(readl(&clock->ctrl) | 1, &clock->ctrl);
 299}
 300
 301static int tnetd7200_get_clock_base(int clock_id, u32 *bootcr)
 302{
 303        if (*bootcr & BOOT_PLL_ASYNC_MODE)
 304                /* Async */
 305                switch (clock_id) {
 306                case TNETD7200_CLOCK_ID_DSP:
 307                        return AR7_REF_CLOCK;
 308                default:
 309                        return AR7_AFE_CLOCK;
 310                }
 311        else
 312                /* Sync */
 313                if (*bootcr & BOOT_PLL_2TO1_MODE)
 314                        /* 2:1 */
 315                        switch (clock_id) {
 316                        case TNETD7200_CLOCK_ID_DSP:
 317                                return AR7_REF_CLOCK;
 318                        default:
 319                                return AR7_AFE_CLOCK;
 320                        }
 321                else
 322                        /* 1:1 */
 323                        return AR7_REF_CLOCK;
 324}
 325
 326
 327static void __init tnetd7200_init_clocks(void)
 328{
 329        u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
 330        struct tnetd7200_clocks *clocks =
 331                                        ioremap_nocache(AR7_REGS_CLOCKS,
 332                                        sizeof(struct tnetd7200_clocks));
 333        int cpu_base, cpu_mul, cpu_prediv, cpu_postdiv;
 334        int dsp_base, dsp_mul, dsp_prediv, dsp_postdiv;
 335        int usb_base, usb_mul, usb_prediv, usb_postdiv;
 336
 337        cpu_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_CPU, bootcr);
 338        dsp_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_DSP, bootcr);
 339
 340        if (*bootcr & BOOT_PLL_ASYNC_MODE) {
 341                printk(KERN_INFO "Clocks: Async mode\n");
 342
 343                printk(KERN_INFO "Clocks: Setting DSP clock\n");
 344                calculate(dsp_base, TNETD7200_DEF_DSP_CLK,
 345                        &dsp_prediv, &dsp_postdiv, &dsp_mul);
 346                ar7_bus_clock =
 347                        ((dsp_base / dsp_prediv) * dsp_mul) / dsp_postdiv;
 348                tnetd7200_set_clock(dsp_base, &clocks->dsp,
 349                        dsp_prediv, dsp_postdiv * 2, dsp_postdiv, dsp_mul * 2,
 350                        ar7_bus_clock);
 351
 352                printk(KERN_INFO "Clocks: Setting CPU clock\n");
 353                calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
 354                        &cpu_postdiv, &cpu_mul);
 355                ar7_cpu_clock =
 356                        ((cpu_base / cpu_prediv) * cpu_mul) / cpu_postdiv;
 357                tnetd7200_set_clock(cpu_base, &clocks->cpu,
 358                        cpu_prediv, cpu_postdiv, -1, cpu_mul,
 359                        ar7_cpu_clock);
 360
 361        } else
 362                if (*bootcr & BOOT_PLL_2TO1_MODE) {
 363                        printk(KERN_INFO "Clocks: Sync 2:1 mode\n");
 364
 365                        printk(KERN_INFO "Clocks: Setting CPU clock\n");
 366                        calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
 367                                &cpu_postdiv, &cpu_mul);
 368                        ar7_cpu_clock = ((cpu_base / cpu_prediv) * cpu_mul)
 369                                                                / cpu_postdiv;
 370                        tnetd7200_set_clock(cpu_base, &clocks->cpu,
 371                                cpu_prediv, cpu_postdiv, -1, cpu_mul,
 372                                ar7_cpu_clock);
 373
 374                        printk(KERN_INFO "Clocks: Setting DSP clock\n");
 375                        calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
 376                                &dsp_postdiv, &dsp_mul);
 377                        ar7_bus_clock = ar7_cpu_clock / 2;
 378                        tnetd7200_set_clock(dsp_base, &clocks->dsp,
 379                                dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
 380                                dsp_mul * 2, ar7_bus_clock);
 381                } else {
 382                        printk(KERN_INFO "Clocks: Sync 1:1 mode\n");
 383
 384                        printk(KERN_INFO "Clocks: Setting DSP clock\n");
 385                        calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
 386                                &dsp_postdiv, &dsp_mul);
 387                        ar7_bus_clock = ((dsp_base / dsp_prediv) * dsp_mul)
 388                                                                / dsp_postdiv;
 389                        tnetd7200_set_clock(dsp_base, &clocks->dsp,
 390                                dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
 391                                dsp_mul * 2, ar7_bus_clock);
 392
 393                        ar7_cpu_clock = ar7_bus_clock;
 394                }
 395
 396        printk(KERN_INFO "Clocks: Setting USB clock\n");
 397        usb_base = ar7_bus_clock;
 398        calculate(usb_base, TNETD7200_DEF_USB_CLK, &usb_prediv,
 399                &usb_postdiv, &usb_mul);
 400        tnetd7200_set_clock(usb_base, &clocks->usb,
 401                usb_prediv, usb_postdiv, -1, usb_mul,
 402                TNETD7200_DEF_USB_CLK);
 403
 404        ar7_dsp_clock = ar7_cpu_clock;
 405
 406        iounmap(clocks);
 407        iounmap(bootcr);
 408}
 409
 410int __init ar7_init_clocks(void)
 411{
 412        switch (ar7_chip_id()) {
 413        case AR7_CHIP_7100:
 414        case AR7_CHIP_7200:
 415                tnetd7200_init_clocks();
 416                break;
 417        case AR7_CHIP_7300:
 418                ar7_dsp_clock = tnetd7300_dsp_clock();
 419                tnetd7300_init_clocks();
 420                break;
 421        default:
 422                break;
 423        }
 424
 425        return 0;
 426}
 427arch_initcall(ar7_init_clocks);
 428