linux/arch/mips/ar7/clock.c
<<
>>
Prefs
   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/clk.h>
  17
  18#include <asm/addrspace.h>
  19#include <asm/mach-ar7/ar7.h>
  20
  21#define BOOT_PLL_SOURCE_MASK    0x3
  22#define CPU_PLL_SOURCE_SHIFT    16
  23#define BUS_PLL_SOURCE_SHIFT    14
  24#define USB_PLL_SOURCE_SHIFT    18
  25#define DSP_PLL_SOURCE_SHIFT    22
  26#define BOOT_PLL_SOURCE_AFE     0
  27#define BOOT_PLL_SOURCE_BUS     0
  28#define BOOT_PLL_SOURCE_REF     1
  29#define BOOT_PLL_SOURCE_XTAL    2
  30#define BOOT_PLL_SOURCE_CPU     3
  31#define BOOT_PLL_BYPASS         0x00000020
  32#define BOOT_PLL_ASYNC_MODE     0x02000000
  33#define BOOT_PLL_2TO1_MODE      0x00008000
  34
  35#define TNETD7200_CLOCK_ID_CPU  0
  36#define TNETD7200_CLOCK_ID_DSP  1
  37#define TNETD7200_CLOCK_ID_USB  2
  38
  39#define TNETD7200_DEF_CPU_CLK   211000000
  40#define TNETD7200_DEF_DSP_CLK   125000000
  41#define TNETD7200_DEF_USB_CLK   48000000
  42
  43struct tnetd7300_clock {
  44        u32 ctrl;
  45#define PREDIV_MASK     0x001f0000
  46#define PREDIV_SHIFT    16
  47#define POSTDIV_MASK    0x0000001f
  48        u32 unused1[3];
  49        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};
  58
  59struct tnetd7300_clocks {
  60        struct tnetd7300_clock bus;
  61        struct tnetd7300_clock cpu;
  62        struct tnetd7300_clock usb;
  63        struct tnetd7300_clock dsp;
  64};
  65
  66struct tnetd7200_clock {
  67        u32 ctrl;
  68        u32 unused1[3];
  69#define DIVISOR_ENABLE_MASK 0x00008000
  70        u32 mul;
  71        u32 prediv;
  72        u32 postdiv;
  73        u32 postdiv2;
  74        u32 unused2[6];
  75        u32 cmd;
  76        u32 status;
  77        u32 cmden;
  78        u32 padding[15];
  79};
  80
  81struct tnetd7200_clocks {
  82        struct tnetd7200_clock cpu;
  83        struct tnetd7200_clock dsp;
  84        struct tnetd7200_clock usb;
  85};
  86
  87static struct clk bus_clk = {
  88        .rate   = 125000000,
  89};
  90
  91static struct clk cpu_clk = {
  92        .rate   = 150000000,
  93};
  94
  95static struct clk dsp_clk;
  96static struct clk vbus_clk;
  97
  98static void approximate(int base, int target, int *prediv,
  99                        int *postdiv, int *mul)
 100{
 101        int i, j, k, freq, res = target;
 102        for (i = 1; i <= 16; i++)
 103                for (j = 1; j <= 32; j++)
 104                        for (k = 1; k <= 32; k++) {
 105                                freq = abs(base / j * i / k - target);
 106                                if (freq < res) {
 107                                        res = freq;
 108                                        *mul = i;
 109                                        *prediv = j;
 110                                        *postdiv = k;
 111                                }
 112                        }
 113}
 114
 115static void calculate(int base, int target, int *prediv, int *postdiv,
 116        int *mul)
 117{
 118        int tmp_gcd, tmp_base, tmp_freq;
 119
 120        for (*prediv = 1; *prediv <= 32; (*prediv)++) {
 121                tmp_base = base / *prediv;
 122                tmp_gcd = gcd(target, tmp_base);
 123                *mul = target / tmp_gcd;
 124                *postdiv = tmp_base / tmp_gcd;
 125                if ((*mul < 1) || (*mul >= 16))
 126                        continue;
 127                if ((*postdiv > 0) & (*postdiv <= 32))
 128                        break;
 129        }
 130
 131        if (base / *prediv * *mul / *postdiv != target) {
 132                approximate(base, target, prediv, postdiv, mul);
 133                tmp_freq = base / *prediv * *mul / *postdiv;
 134                printk(KERN_WARNING
 135                       "Adjusted requested frequency %d to %d\n",
 136                       target, tmp_freq);
 137        }
 138
 139        printk(KERN_DEBUG "Clocks: prediv: %d, postdiv: %d, mul: %d\n",
 140               *prediv, *postdiv, *mul);
 141}
 142
 143static int tnetd7300_dsp_clock(void)
 144{
 145        u32 didr1, didr2;
 146        u8 rev = ar7_chip_rev();
 147        didr1 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x18));
 148        didr2 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x1c));
 149        if (didr2 & (1 << 23))
 150                return 0;
 151        if ((rev >= 0x23) && (rev != 0x57))
 152                return 250000000;
 153        if ((((didr2 & 0x1fff) << 10) | ((didr1 & 0xffc00000) >> 22))
 154            > 4208000)
 155                return 250000000;
 156        return 0;
 157}
 158
 159static int tnetd7300_get_clock(u32 shift, struct tnetd7300_clock *clock,
 160        u32 *bootcr, u32 bus_clock)
 161{
 162        int product;
 163        int base_clock = AR7_REF_CLOCK;
 164        u32 ctrl = readl(&clock->ctrl);
 165        u32 pll = readl(&clock->pll);
 166        int prediv = ((ctrl & PREDIV_MASK) >> PREDIV_SHIFT) + 1;
 167        int postdiv = (ctrl & POSTDIV_MASK) + 1;
 168        int divisor = prediv * postdiv;
 169        int mul = ((pll & MUL_MASK) >> MUL_SHIFT) + 1;
 170
 171        switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
 172        case BOOT_PLL_SOURCE_BUS:
 173                base_clock = bus_clock;
 174                break;
 175        case BOOT_PLL_SOURCE_REF:
 176                base_clock = AR7_REF_CLOCK;
 177                break;
 178        case BOOT_PLL_SOURCE_XTAL:
 179                base_clock = AR7_XTAL_CLOCK;
 180                break;
 181        case BOOT_PLL_SOURCE_CPU:
 182                base_clock = cpu_clk.rate;
 183                break;
 184        }
 185
 186        if (*bootcr & BOOT_PLL_BYPASS)
 187                return base_clock / divisor;
 188
 189        if ((pll & PLL_MODE_MASK) == 0)
 190                return (base_clock >> (mul / 16 + 1)) / divisor;
 191
 192        if ((pll & (PLL_NDIV | PLL_DIV)) == (PLL_NDIV | PLL_DIV)) {
 193                product = (mul & 1) ?
 194                        (base_clock * mul) >> 1 :
 195                        (base_clock * (mul - 1)) >> 2;
 196                return product / divisor;
 197        }
 198
 199        if (mul == 16)
 200                return base_clock / divisor;
 201
 202        return base_clock * mul / divisor;
 203}
 204
 205static void tnetd7300_set_clock(u32 shift, struct tnetd7300_clock *clock,
 206        u32 *bootcr, u32 frequency)
 207{
 208        int prediv, postdiv, mul;
 209        int base_clock = bus_clk.rate;
 210
 211        switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
 212        case BOOT_PLL_SOURCE_BUS:
 213                base_clock = bus_clk.rate;
 214                break;
 215        case BOOT_PLL_SOURCE_REF:
 216                base_clock = AR7_REF_CLOCK;
 217                break;
 218        case BOOT_PLL_SOURCE_XTAL:
 219                base_clock = AR7_XTAL_CLOCK;
 220                break;
 221        case BOOT_PLL_SOURCE_CPU:
 222                base_clock = cpu_clk.rate;
 223                break;
 224        }
 225
 226        calculate(base_clock, frequency, &prediv, &postdiv, &mul);
 227
 228        writel(((prediv - 1) << PREDIV_SHIFT) | (postdiv - 1), &clock->ctrl);
 229        mdelay(1);
 230        writel(4, &clock->pll);
 231        while (readl(&clock->pll) & PLL_STATUS)
 232                ;
 233        writel(((mul - 1) << MUL_SHIFT) | (0xff << 3) | 0x0e, &clock->pll);
 234        mdelay(75);
 235}
 236
 237static void __init tnetd7300_init_clocks(void)
 238{
 239        u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
 240        struct tnetd7300_clocks *clocks =
 241                                        ioremap_nocache(UR8_REGS_CLOCKS,
 242                                        sizeof(struct tnetd7300_clocks));
 243
 244        bus_clk.rate = tnetd7300_get_clock(BUS_PLL_SOURCE_SHIFT,
 245                &clocks->bus, bootcr, AR7_AFE_CLOCK);
 246
 247        if (*bootcr & BOOT_PLL_ASYNC_MODE)
 248                cpu_clk.rate = tnetd7300_get_clock(CPU_PLL_SOURCE_SHIFT,
 249                        &clocks->cpu, bootcr, AR7_AFE_CLOCK);
 250        else
 251                cpu_clk.rate = bus_clk.rate;
 252
 253        if (dsp_clk.rate == 250000000)
 254                tnetd7300_set_clock(DSP_PLL_SOURCE_SHIFT, &clocks->dsp,
 255                        bootcr, dsp_clk.rate);
 256
 257        iounmap(clocks);
 258        iounmap(bootcr);
 259}
 260
 261static void tnetd7200_set_clock(int base, struct tnetd7200_clock *clock,
 262        int prediv, int postdiv, int postdiv2, int mul, u32 frequency)
 263{
 264        printk(KERN_INFO
 265                "Clocks: base = %d, frequency = %u, prediv = %d, "
 266                "postdiv = %d, postdiv2 = %d, mul = %d\n",
 267                base, frequency, prediv, postdiv, postdiv2, mul);
 268
 269        writel(0, &clock->ctrl);
 270        writel(DIVISOR_ENABLE_MASK | ((prediv - 1) & 0x1F), &clock->prediv);
 271        writel((mul - 1) & 0xF, &clock->mul);
 272
 273        while (readl(&clock->status) & 0x1)
 274                ; /* nop */
 275
 276        writel(DIVISOR_ENABLE_MASK | ((postdiv - 1) & 0x1F), &clock->postdiv);
 277
 278        writel(readl(&clock->cmden) | 1, &clock->cmden);
 279        writel(readl(&clock->cmd) | 1, &clock->cmd);
 280
 281        while (readl(&clock->status) & 0x1)
 282                ; /* nop */
 283
 284        writel(DIVISOR_ENABLE_MASK | ((postdiv2 - 1) & 0x1F), &clock->postdiv2);
 285
 286        writel(readl(&clock->cmden) | 1, &clock->cmden);
 287        writel(readl(&clock->cmd) | 1, &clock->cmd);
 288
 289        while (readl(&clock->status) & 0x1)
 290                ; /* nop */
 291
 292        writel(readl(&clock->ctrl) | 1, &clock->ctrl);
 293}
 294
 295static int tnetd7200_get_clock_base(int clock_id, u32 *bootcr)
 296{
 297        if (*bootcr & BOOT_PLL_ASYNC_MODE)
 298                /* Async */
 299                switch (clock_id) {
 300                case TNETD7200_CLOCK_ID_DSP:
 301                        return AR7_REF_CLOCK;
 302                default:
 303                        return AR7_AFE_CLOCK;
 304                }
 305        else
 306                /* Sync */
 307                if (*bootcr & BOOT_PLL_2TO1_MODE)
 308                        /* 2:1 */
 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                        /* 1:1 */
 317                        return AR7_REF_CLOCK;
 318}
 319
 320
 321static void __init tnetd7200_init_clocks(void)
 322{
 323        u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
 324        struct tnetd7200_clocks *clocks =
 325                                        ioremap_nocache(AR7_REGS_CLOCKS,
 326                                        sizeof(struct tnetd7200_clocks));
 327        int cpu_base, cpu_mul, cpu_prediv, cpu_postdiv;
 328        int dsp_base, dsp_mul, dsp_prediv, dsp_postdiv;
 329        int usb_base, usb_mul, usb_prediv, usb_postdiv;
 330
 331        cpu_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_CPU, bootcr);
 332        dsp_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_DSP, bootcr);
 333
 334        if (*bootcr & BOOT_PLL_ASYNC_MODE) {
 335                printk(KERN_INFO "Clocks: Async mode\n");
 336
 337                printk(KERN_INFO "Clocks: Setting DSP clock\n");
 338                calculate(dsp_base, TNETD7200_DEF_DSP_CLK,
 339                        &dsp_prediv, &dsp_postdiv, &dsp_mul);
 340                bus_clk.rate =
 341                        ((dsp_base / dsp_prediv) * dsp_mul) / dsp_postdiv;
 342                tnetd7200_set_clock(dsp_base, &clocks->dsp,
 343                        dsp_prediv, dsp_postdiv * 2, dsp_postdiv, dsp_mul * 2,
 344                        bus_clk.rate);
 345
 346                printk(KERN_INFO "Clocks: Setting CPU clock\n");
 347                calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
 348                        &cpu_postdiv, &cpu_mul);
 349                cpu_clk.rate =
 350                        ((cpu_base / cpu_prediv) * cpu_mul) / cpu_postdiv;
 351                tnetd7200_set_clock(cpu_base, &clocks->cpu,
 352                        cpu_prediv, cpu_postdiv, -1, cpu_mul,
 353                        cpu_clk.rate);
 354
 355        } else
 356                if (*bootcr & BOOT_PLL_2TO1_MODE) {
 357                        printk(KERN_INFO "Clocks: Sync 2:1 mode\n");
 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 = ((cpu_base / cpu_prediv) * cpu_mul)
 363                                                                / cpu_postdiv;
 364                        tnetd7200_set_clock(cpu_base, &clocks->cpu,
 365                                cpu_prediv, cpu_postdiv, -1, cpu_mul,
 366                                cpu_clk.rate);
 367
 368                        printk(KERN_INFO "Clocks: Setting DSP clock\n");
 369                        calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
 370                                &dsp_postdiv, &dsp_mul);
 371                        bus_clk.rate = cpu_clk.rate / 2;
 372                        tnetd7200_set_clock(dsp_base, &clocks->dsp,
 373                                dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
 374                                dsp_mul * 2, bus_clk.rate);
 375                } else {
 376                        printk(KERN_INFO "Clocks: Sync 1:1 mode\n");
 377
 378                        printk(KERN_INFO "Clocks: Setting DSP clock\n");
 379                        calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
 380                                &dsp_postdiv, &dsp_mul);
 381                        bus_clk.rate = ((dsp_base / dsp_prediv) * dsp_mul)
 382                                                                / dsp_postdiv;
 383                        tnetd7200_set_clock(dsp_base, &clocks->dsp,
 384                                dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
 385                                dsp_mul * 2, bus_clk.rate);
 386
 387                        cpu_clk.rate = bus_clk.rate;
 388                }
 389
 390        printk(KERN_INFO "Clocks: Setting USB clock\n");
 391        usb_base = bus_clk.rate;
 392        calculate(usb_base, TNETD7200_DEF_USB_CLK, &usb_prediv,
 393                &usb_postdiv, &usb_mul);
 394        tnetd7200_set_clock(usb_base, &clocks->usb,
 395                usb_prediv, usb_postdiv, -1, usb_mul,
 396                TNETD7200_DEF_USB_CLK);
 397
 398        dsp_clk.rate = cpu_clk.rate;
 399
 400        iounmap(clocks);
 401        iounmap(bootcr);
 402}
 403
 404/*
 405 * Linux clock API
 406 */
 407int clk_enable(struct clk *clk)
 408{
 409        return 0;
 410}
 411EXPORT_SYMBOL(clk_enable);
 412
 413void clk_disable(struct clk *clk)
 414{
 415}
 416EXPORT_SYMBOL(clk_disable);
 417
 418unsigned long clk_get_rate(struct clk *clk)
 419{
 420        if (!clk)
 421                return 0;
 422
 423        return clk->rate;
 424}
 425EXPORT_SYMBOL(clk_get_rate);
 426
 427struct clk *clk_get(struct device *dev, const char *id)
 428{
 429        if (!strcmp(id, "bus"))
 430                return &bus_clk;
 431        /* cpmac and vbus share the same rate */
 432        if (!strcmp(id, "cpmac"))
 433                return &vbus_clk;
 434        if (!strcmp(id, "cpu"))
 435                return &cpu_clk;
 436        if (!strcmp(id, "dsp"))
 437                return &dsp_clk;
 438        if (!strcmp(id, "vbus"))
 439                return &vbus_clk;
 440        return ERR_PTR(-ENOENT);
 441}
 442EXPORT_SYMBOL(clk_get);
 443
 444void clk_put(struct clk *clk)
 445{
 446}
 447EXPORT_SYMBOL(clk_put);
 448
 449void __init ar7_init_clocks(void)
 450{
 451        switch (ar7_chip_id()) {
 452        case AR7_CHIP_7100:
 453        case AR7_CHIP_7200:
 454                tnetd7200_init_clocks();
 455                break;
 456        case AR7_CHIP_7300:
 457                dsp_clk.rate = tnetd7300_dsp_clock();
 458                tnetd7300_init_clocks();
 459                break;
 460        default:
 461                break;
 462        }
 463        /* adjust vbus clock rate */
 464        vbus_clk.rate = bus_clk.rate / 2;
 465}
 466
 467/* dummy functions, should not be called */
 468long clk_round_rate(struct clk *clk, unsigned long rate)
 469{
 470        WARN_ON(clk);
 471        return 0;
 472}
 473EXPORT_SYMBOL(clk_round_rate);
 474
 475int clk_set_rate(struct clk *clk, unsigned long rate)
 476{
 477        WARN_ON(clk);
 478        return 0;
 479}
 480EXPORT_SYMBOL(clk_set_rate);
 481
 482int clk_set_parent(struct clk *clk, struct clk *parent)
 483{
 484        WARN_ON(clk);
 485        return 0;
 486}
 487EXPORT_SYMBOL(clk_set_parent);
 488
 489struct clk *clk_get_parent(struct clk *clk)
 490{
 491        WARN_ON(clk);
 492        return NULL;
 493}
 494EXPORT_SYMBOL(clk_get_parent);
 495