linux/arch/mips/ar7/clock.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
   4 * Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
   5 * Copyright (C) 2009 Florian Fainelli <florian@openwrt.org>
   6 */
   7
   8#include <linux/kernel.h>
   9#include <linux/init.h>
  10#include <linux/types.h>
  11#include <linux/export.h>
  12#include <linux/delay.h>
  13#include <linux/gcd.h>
  14#include <linux/io.h>
  15#include <linux/err.h>
  16#include <linux/clkdev.h>
  17#include <linux/clk.h>
  18#include <linux/clk-provider.h>
  19
  20#include <asm/addrspace.h>
  21#include <asm/mach-ar7/ar7.h>
  22
  23#define BOOT_PLL_SOURCE_MASK    0x3
  24#define CPU_PLL_SOURCE_SHIFT    16
  25#define BUS_PLL_SOURCE_SHIFT    14
  26#define USB_PLL_SOURCE_SHIFT    18
  27#define DSP_PLL_SOURCE_SHIFT    22
  28#define BOOT_PLL_SOURCE_AFE     0
  29#define BOOT_PLL_SOURCE_BUS     0
  30#define BOOT_PLL_SOURCE_REF     1
  31#define BOOT_PLL_SOURCE_XTAL    2
  32#define BOOT_PLL_SOURCE_CPU     3
  33#define BOOT_PLL_BYPASS         0x00000020
  34#define BOOT_PLL_ASYNC_MODE     0x02000000
  35#define BOOT_PLL_2TO1_MODE      0x00008000
  36
  37#define TNETD7200_CLOCK_ID_CPU  0
  38#define TNETD7200_CLOCK_ID_DSP  1
  39#define TNETD7200_CLOCK_ID_USB  2
  40
  41#define TNETD7200_DEF_CPU_CLK   211000000
  42#define TNETD7200_DEF_DSP_CLK   125000000
  43#define TNETD7200_DEF_USB_CLK   48000000
  44
  45struct tnetd7300_clock {
  46        u32 ctrl;
  47#define PREDIV_MASK     0x001f0000
  48#define PREDIV_SHIFT    16
  49#define POSTDIV_MASK    0x0000001f
  50        u32 unused1[3];
  51        u32 pll;
  52#define MUL_MASK        0x0000f000
  53#define MUL_SHIFT       12
  54#define PLL_MODE_MASK   0x00000001
  55#define PLL_NDIV        0x00000800
  56#define PLL_DIV         0x00000002
  57#define PLL_STATUS      0x00000001
  58        u32 unused2[3];
  59};
  60
  61struct tnetd7300_clocks {
  62        struct tnetd7300_clock bus;
  63        struct tnetd7300_clock cpu;
  64        struct tnetd7300_clock usb;
  65        struct tnetd7300_clock dsp;
  66};
  67
  68struct tnetd7200_clock {
  69        u32 ctrl;
  70        u32 unused1[3];
  71#define DIVISOR_ENABLE_MASK 0x00008000
  72        u32 mul;
  73        u32 prediv;
  74        u32 postdiv;
  75        u32 postdiv2;
  76        u32 unused2[6];
  77        u32 cmd;
  78        u32 status;
  79        u32 cmden;
  80        u32 padding[15];
  81};
  82
  83struct tnetd7200_clocks {
  84        struct tnetd7200_clock cpu;
  85        struct tnetd7200_clock dsp;
  86        struct tnetd7200_clock usb;
  87};
  88
  89struct clk_rate {
  90        u32 rate;
  91};
  92static struct clk_rate bus_clk = {
  93        .rate   = 125000000,
  94};
  95
  96static struct clk_rate cpu_clk = {
  97        .rate   = 150000000,
  98};
  99
 100static void approximate(int base, int target, int *prediv,
 101                        int *postdiv, int *mul)
 102{
 103        int i, j, k, freq, res = target;
 104        for (i = 1; i <= 16; i++)
 105                for (j = 1; j <= 32; j++)
 106                        for (k = 1; k <= 32; k++) {
 107                                freq = abs(base / j * i / k - target);
 108                                if (freq < res) {
 109                                        res = freq;
 110                                        *mul = i;
 111                                        *prediv = j;
 112                                        *postdiv = k;
 113                                }
 114                        }
 115}
 116
 117static void calculate(int base, int target, int *prediv, int *postdiv,
 118        int *mul)
 119{
 120        int tmp_gcd, tmp_base, tmp_freq;
 121
 122        for (*prediv = 1; *prediv <= 32; (*prediv)++) {
 123                tmp_base = base / *prediv;
 124                tmp_gcd = gcd(target, tmp_base);
 125                *mul = target / tmp_gcd;
 126                *postdiv = tmp_base / tmp_gcd;
 127                if ((*mul < 1) || (*mul >= 16))
 128                        continue;
 129                if ((*postdiv > 0) & (*postdiv <= 32))
 130                        break;
 131        }
 132
 133        if (base / *prediv * *mul / *postdiv != target) {
 134                approximate(base, target, prediv, postdiv, mul);
 135                tmp_freq = base / *prediv * *mul / *postdiv;
 136                printk(KERN_WARNING
 137                       "Adjusted requested frequency %d to %d\n",
 138                       target, tmp_freq);
 139        }
 140
 141        printk(KERN_DEBUG "Clocks: prediv: %d, postdiv: %d, mul: %d\n",
 142               *prediv, *postdiv, *mul);
 143}
 144
 145static int tnetd7300_dsp_clock(void)
 146{
 147        u32 didr1, didr2;
 148        u8 rev = ar7_chip_rev();
 149        didr1 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x18));
 150        didr2 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x1c));
 151        if (didr2 & (1 << 23))
 152                return 0;
 153        if ((rev >= 0x23) && (rev != 0x57))
 154                return 250000000;
 155        if ((((didr2 & 0x1fff) << 10) | ((didr1 & 0xffc00000) >> 22))
 156            > 4208000)
 157                return 250000000;
 158        return 0;
 159}
 160
 161static int tnetd7300_get_clock(u32 shift, struct tnetd7300_clock *clock,
 162        u32 *bootcr, u32 bus_clock)
 163{
 164        int product;
 165        int base_clock = AR7_REF_CLOCK;
 166        u32 ctrl = readl(&clock->ctrl);
 167        u32 pll = readl(&clock->pll);
 168        int prediv = ((ctrl & PREDIV_MASK) >> PREDIV_SHIFT) + 1;
 169        int postdiv = (ctrl & POSTDIV_MASK) + 1;
 170        int divisor = prediv * postdiv;
 171        int mul = ((pll & MUL_MASK) >> MUL_SHIFT) + 1;
 172
 173        switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
 174        case BOOT_PLL_SOURCE_BUS:
 175                base_clock = bus_clock;
 176                break;
 177        case BOOT_PLL_SOURCE_REF:
 178                base_clock = AR7_REF_CLOCK;
 179                break;
 180        case BOOT_PLL_SOURCE_XTAL:
 181                base_clock = AR7_XTAL_CLOCK;
 182                break;
 183        case BOOT_PLL_SOURCE_CPU:
 184                base_clock = cpu_clk.rate;
 185                break;
 186        }
 187
 188        if (*bootcr & BOOT_PLL_BYPASS)
 189                return base_clock / divisor;
 190
 191        if ((pll & PLL_MODE_MASK) == 0)
 192                return (base_clock >> (mul / 16 + 1)) / divisor;
 193
 194        if ((pll & (PLL_NDIV | PLL_DIV)) == (PLL_NDIV | PLL_DIV)) {
 195                product = (mul & 1) ?
 196                        (base_clock * mul) >> 1 :
 197                        (base_clock * (mul - 1)) >> 2;
 198                return product / divisor;
 199        }
 200
 201        if (mul == 16)
 202                return base_clock / divisor;
 203
 204        return base_clock * mul / divisor;
 205}
 206
 207static void tnetd7300_set_clock(u32 shift, struct tnetd7300_clock *clock,
 208        u32 *bootcr, u32 frequency)
 209{
 210        int prediv, postdiv, mul;
 211        int base_clock = bus_clk.rate;
 212
 213        switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
 214        case BOOT_PLL_SOURCE_BUS:
 215                base_clock = bus_clk.rate;
 216                break;
 217        case BOOT_PLL_SOURCE_REF:
 218                base_clock = AR7_REF_CLOCK;
 219                break;
 220        case BOOT_PLL_SOURCE_XTAL:
 221                base_clock = AR7_XTAL_CLOCK;
 222                break;
 223        case BOOT_PLL_SOURCE_CPU:
 224                base_clock = cpu_clk.rate;
 225                break;
 226        }
 227
 228        calculate(base_clock, frequency, &prediv, &postdiv, &mul);
 229
 230        writel(((prediv - 1) << PREDIV_SHIFT) | (postdiv - 1), &clock->ctrl);
 231        mdelay(1);
 232        writel(4, &clock->pll);
 233        while (readl(&clock->pll) & PLL_STATUS)
 234                ;
 235        writel(((mul - 1) << MUL_SHIFT) | (0xff << 3) | 0x0e, &clock->pll);
 236        mdelay(75);
 237}
 238
 239static void __init tnetd7300_init_clocks(void)
 240{
 241        u32 *bootcr = (u32 *)ioremap(AR7_REGS_DCL, 4);
 242        struct tnetd7300_clocks *clocks =
 243                                        ioremap(UR8_REGS_CLOCKS,
 244                                        sizeof(struct tnetd7300_clocks));
 245        u32 dsp_clk;
 246        struct clk *clk;
 247
 248        bus_clk.rate = tnetd7300_get_clock(BUS_PLL_SOURCE_SHIFT,
 249                &clocks->bus, bootcr, AR7_AFE_CLOCK);
 250
 251        if (*bootcr & BOOT_PLL_ASYNC_MODE)
 252                cpu_clk.rate = tnetd7300_get_clock(CPU_PLL_SOURCE_SHIFT,
 253                        &clocks->cpu, bootcr, AR7_AFE_CLOCK);
 254        else
 255                cpu_clk.rate = bus_clk.rate;
 256
 257        dsp_clk = tnetd7300_dsp_clock();
 258        if (dsp_clk == 250000000)
 259                tnetd7300_set_clock(DSP_PLL_SOURCE_SHIFT, &clocks->dsp,
 260                        bootcr, dsp_clk);
 261
 262        iounmap(clocks);
 263        iounmap(bootcr);
 264
 265        clk = clk_register_fixed_rate(NULL, "cpu", NULL, 0, cpu_clk.rate);
 266        clkdev_create(clk, "cpu", NULL);
 267        clk = clk_register_fixed_rate(NULL, "dsp", NULL, 0, dsp_clk);
 268        clkdev_create(clk, "dsp", NULL);
 269}
 270
 271static void tnetd7200_set_clock(int base, struct tnetd7200_clock *clock,
 272        int prediv, int postdiv, int postdiv2, int mul, u32 frequency)
 273{
 274        printk(KERN_INFO
 275                "Clocks: base = %d, frequency = %u, prediv = %d, "
 276                "postdiv = %d, postdiv2 = %d, mul = %d\n",
 277                base, frequency, prediv, postdiv, postdiv2, mul);
 278
 279        writel(0, &clock->ctrl);
 280        writel(DIVISOR_ENABLE_MASK | ((prediv - 1) & 0x1F), &clock->prediv);
 281        writel((mul - 1) & 0xF, &clock->mul);
 282
 283        while (readl(&clock->status) & 0x1)
 284                ; /* nop */
 285
 286        writel(DIVISOR_ENABLE_MASK | ((postdiv - 1) & 0x1F), &clock->postdiv);
 287
 288        writel(readl(&clock->cmden) | 1, &clock->cmden);
 289        writel(readl(&clock->cmd) | 1, &clock->cmd);
 290
 291        while (readl(&clock->status) & 0x1)
 292                ; /* nop */
 293
 294        writel(DIVISOR_ENABLE_MASK | ((postdiv2 - 1) & 0x1F), &clock->postdiv2);
 295
 296        writel(readl(&clock->cmden) | 1, &clock->cmden);
 297        writel(readl(&clock->cmd) | 1, &clock->cmd);
 298
 299        while (readl(&clock->status) & 0x1)
 300                ; /* nop */
 301
 302        writel(readl(&clock->ctrl) | 1, &clock->ctrl);
 303}
 304
 305static int tnetd7200_get_clock_base(int clock_id, u32 *bootcr)
 306{
 307        if (*bootcr & BOOT_PLL_ASYNC_MODE)
 308                /* Async */
 309                switch (clock_id) {
 310                case TNETD7200_CLOCK_ID_DSP:
 311                        return AR7_REF_CLOCK;
 312                default:
 313                        return AR7_AFE_CLOCK;
 314                }
 315        else
 316                /* Sync */
 317                if (*bootcr & BOOT_PLL_2TO1_MODE)
 318                        /* 2:1 */
 319                        switch (clock_id) {
 320                        case TNETD7200_CLOCK_ID_DSP:
 321                                return AR7_REF_CLOCK;
 322                        default:
 323                                return AR7_AFE_CLOCK;
 324                        }
 325                else
 326                        /* 1:1 */
 327                        return AR7_REF_CLOCK;
 328}
 329
 330
 331static void __init tnetd7200_init_clocks(void)
 332{
 333        u32 *bootcr = (u32 *)ioremap(AR7_REGS_DCL, 4);
 334        struct tnetd7200_clocks *clocks =
 335                                        ioremap(AR7_REGS_CLOCKS,
 336                                        sizeof(struct tnetd7200_clocks));
 337        int cpu_base, cpu_mul, cpu_prediv, cpu_postdiv;
 338        int dsp_base, dsp_mul, dsp_prediv, dsp_postdiv;
 339        int usb_base, usb_mul, usb_prediv, usb_postdiv;
 340        struct clk *clk;
 341
 342        cpu_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_CPU, bootcr);
 343        dsp_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_DSP, bootcr);
 344
 345        if (*bootcr & BOOT_PLL_ASYNC_MODE) {
 346                printk(KERN_INFO "Clocks: Async mode\n");
 347
 348                printk(KERN_INFO "Clocks: Setting DSP clock\n");
 349                calculate(dsp_base, TNETD7200_DEF_DSP_CLK,
 350                        &dsp_prediv, &dsp_postdiv, &dsp_mul);
 351                bus_clk.rate =
 352                        ((dsp_base / dsp_prediv) * dsp_mul) / dsp_postdiv;
 353                tnetd7200_set_clock(dsp_base, &clocks->dsp,
 354                        dsp_prediv, dsp_postdiv * 2, dsp_postdiv, dsp_mul * 2,
 355                        bus_clk.rate);
 356
 357                printk(KERN_INFO "Clocks: Setting CPU clock\n");
 358                calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
 359                        &cpu_postdiv, &cpu_mul);
 360                cpu_clk.rate =
 361                        ((cpu_base / cpu_prediv) * cpu_mul) / cpu_postdiv;
 362                tnetd7200_set_clock(cpu_base, &clocks->cpu,
 363                        cpu_prediv, cpu_postdiv, -1, cpu_mul,
 364                        cpu_clk.rate);
 365
 366        } else
 367                if (*bootcr & BOOT_PLL_2TO1_MODE) {
 368                        printk(KERN_INFO "Clocks: Sync 2:1 mode\n");
 369
 370                        printk(KERN_INFO "Clocks: Setting CPU clock\n");
 371                        calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
 372                                &cpu_postdiv, &cpu_mul);
 373                        cpu_clk.rate = ((cpu_base / cpu_prediv) * cpu_mul)
 374                                                                / cpu_postdiv;
 375                        tnetd7200_set_clock(cpu_base, &clocks->cpu,
 376                                cpu_prediv, cpu_postdiv, -1, cpu_mul,
 377                                cpu_clk.rate);
 378
 379                        printk(KERN_INFO "Clocks: Setting DSP clock\n");
 380                        calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
 381                                &dsp_postdiv, &dsp_mul);
 382                        bus_clk.rate = cpu_clk.rate / 2;
 383                        tnetd7200_set_clock(dsp_base, &clocks->dsp,
 384                                dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
 385                                dsp_mul * 2, bus_clk.rate);
 386                } else {
 387                        printk(KERN_INFO "Clocks: Sync 1:1 mode\n");
 388
 389                        printk(KERN_INFO "Clocks: Setting DSP clock\n");
 390                        calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
 391                                &dsp_postdiv, &dsp_mul);
 392                        bus_clk.rate = ((dsp_base / dsp_prediv) * dsp_mul)
 393                                                                / dsp_postdiv;
 394                        tnetd7200_set_clock(dsp_base, &clocks->dsp,
 395                                dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
 396                                dsp_mul * 2, bus_clk.rate);
 397
 398                        cpu_clk.rate = bus_clk.rate;
 399                }
 400
 401        printk(KERN_INFO "Clocks: Setting USB clock\n");
 402        usb_base = bus_clk.rate;
 403        calculate(usb_base, TNETD7200_DEF_USB_CLK, &usb_prediv,
 404                &usb_postdiv, &usb_mul);
 405        tnetd7200_set_clock(usb_base, &clocks->usb,
 406                usb_prediv, usb_postdiv, -1, usb_mul,
 407                TNETD7200_DEF_USB_CLK);
 408
 409        iounmap(clocks);
 410        iounmap(bootcr);
 411
 412        clk = clk_register_fixed_rate(NULL, "cpu", NULL, 0, cpu_clk.rate);
 413        clkdev_create(clk, "cpu", NULL);
 414        clkdev_create(clk, "dsp", NULL);
 415}
 416
 417void __init ar7_init_clocks(void)
 418{
 419        struct clk *clk;
 420
 421        switch (ar7_chip_id()) {
 422        case AR7_CHIP_7100:
 423        case AR7_CHIP_7200:
 424                tnetd7200_init_clocks();
 425                break;
 426        case AR7_CHIP_7300:
 427                tnetd7300_init_clocks();
 428                break;
 429        default:
 430                break;
 431        }
 432        clk = clk_register_fixed_rate(NULL, "bus", NULL, 0, bus_clk.rate);
 433        clkdev_create(clk, "bus", NULL);
 434        /* adjust vbus clock rate */
 435        clk = clk_register_fixed_factor(NULL, "vbus", "bus", 0, 1, 2);
 436        clkdev_create(clk, "vbus", NULL);
 437        clkdev_create(clk, "cpmac", "cpmac.1");
 438        clkdev_create(clk, "cpmac", "cpmac.1");
 439}
 440