linux/drivers/clk/pxa/clk-pxa25x.c
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   1/*
   2 * Marvell PXA25x family clocks
   3 *
   4 * Copyright (C) 2014 Robert Jarzmik
   5 *
   6 * Heavily inspired from former arch/arm/mach-pxa/pxa25x.c.
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License as published by
  10 * the Free Software Foundation; version 2 of the License.
  11 *
  12 * For non-devicetree platforms. Once pxa is fully converted to devicetree, this
  13 * should go away.
  14 */
  15#include <linux/clk-provider.h>
  16#include <linux/clk.h>
  17#include <linux/clkdev.h>
  18#include <linux/io.h>
  19#include <linux/of.h>
  20#include <mach/pxa2xx-regs.h>
  21#include <mach/smemc.h>
  22
  23#include <dt-bindings/clock/pxa-clock.h>
  24#include "clk-pxa.h"
  25
  26#define KHz 1000
  27#define MHz (1000 * 1000)
  28
  29enum {
  30        PXA_CORE_RUN = 0,
  31        PXA_CORE_TURBO,
  32};
  33
  34#define PXA25x_CLKCFG(T)                        \
  35        (CLKCFG_FCS |                           \
  36         ((T) ? CLKCFG_TURBO : 0))
  37#define PXA25x_CCCR(N2, M, L) (N2 << 7 | M << 5 | L)
  38
  39#define MDCNFG_DRAC2(mdcnfg)    (((mdcnfg) >> 21) & 0x3)
  40#define MDCNFG_DRAC0(mdcnfg)    (((mdcnfg) >> 5) & 0x3)
  41
  42/* Define the refresh period in mSec for the SDRAM and the number of rows */
  43#define SDRAM_TREF      64      /* standard 64ms SDRAM */
  44
  45/*
  46 * Various clock factors driven by the CCCR register.
  47 */
  48
  49/* Crystal Frequency to Memory Frequency Multiplier (L) */
  50static unsigned char L_clk_mult[32] = { 0, 27, 32, 36, 40, 45, 0, };
  51
  52/* Memory Frequency to Run Mode Frequency Multiplier (M) */
  53static unsigned char M_clk_mult[4] = { 0, 1, 2, 4 };
  54
  55/* Run Mode Frequency to Turbo Mode Frequency Multiplier (N) */
  56/* Note: we store the value N * 2 here. */
  57static unsigned char N2_clk_mult[8] = { 0, 0, 2, 3, 4, 0, 6, 0 };
  58
  59static const char * const get_freq_khz[] = {
  60        "core", "run", "cpll", "memory"
  61};
  62
  63static int get_sdram_rows(void)
  64{
  65        static int sdram_rows;
  66        unsigned int drac2 = 0, drac0 = 0;
  67        u32 mdcnfg;
  68
  69        if (sdram_rows)
  70                return sdram_rows;
  71
  72        mdcnfg = readl_relaxed(MDCNFG);
  73
  74        if (mdcnfg & (MDCNFG_DE2 | MDCNFG_DE3))
  75                drac2 = MDCNFG_DRAC2(mdcnfg);
  76
  77        if (mdcnfg & (MDCNFG_DE0 | MDCNFG_DE1))
  78                drac0 = MDCNFG_DRAC0(mdcnfg);
  79
  80        sdram_rows = 1 << (11 + max(drac0, drac2));
  81        return sdram_rows;
  82}
  83
  84static u32 mdrefr_dri(unsigned int freq_khz)
  85{
  86        u32 interval = freq_khz * SDRAM_TREF / get_sdram_rows();
  87
  88        return interval / 32;
  89}
  90
  91/*
  92 * Get the clock frequency as reflected by CCCR and the turbo flag.
  93 * We assume these values have been applied via a fcs.
  94 * If info is not 0 we also display the current settings.
  95 */
  96unsigned int pxa25x_get_clk_frequency_khz(int info)
  97{
  98        struct clk *clk;
  99        unsigned long clks[5];
 100        int i;
 101
 102        for (i = 0; i < ARRAY_SIZE(get_freq_khz); i++) {
 103                clk = clk_get(NULL, get_freq_khz[i]);
 104                if (IS_ERR(clk)) {
 105                        clks[i] = 0;
 106                } else {
 107                        clks[i] = clk_get_rate(clk);
 108                        clk_put(clk);
 109                }
 110        }
 111
 112        if (info) {
 113                pr_info("Run Mode clock: %ld.%02ldMHz\n",
 114                        clks[1] / 1000000, (clks[1] % 1000000) / 10000);
 115                pr_info("Turbo Mode clock: %ld.%02ldMHz\n",
 116                        clks[2] / 1000000, (clks[2] % 1000000) / 10000);
 117                pr_info("Memory clock: %ld.%02ldMHz\n",
 118                        clks[3] / 1000000, (clks[3] % 1000000) / 10000);
 119        }
 120
 121        return (unsigned int)clks[0] / KHz;
 122}
 123
 124static unsigned long clk_pxa25x_memory_get_rate(struct clk_hw *hw,
 125                                                unsigned long parent_rate)
 126{
 127        unsigned long cccr = readl(CCCR);
 128        unsigned int m = M_clk_mult[(cccr >> 5) & 0x03];
 129
 130        return parent_rate / m;
 131}
 132PARENTS(clk_pxa25x_memory) = { "run" };
 133RATE_RO_OPS(clk_pxa25x_memory, "memory");
 134
 135PARENTS(pxa25x_pbus95) = { "ppll_95_85mhz", "ppll_95_85mhz" };
 136PARENTS(pxa25x_pbus147) = { "ppll_147_46mhz", "ppll_147_46mhz" };
 137PARENTS(pxa25x_osc3) = { "osc_3_6864mhz", "osc_3_6864mhz" };
 138
 139#define PXA25X_CKEN(dev_id, con_id, parents, mult, div,                 \
 140                    bit, is_lp, flags)                                  \
 141        PXA_CKEN(dev_id, con_id, bit, parents, mult, div, mult, div,    \
 142                 is_lp,  CKEN, CKEN_ ## bit, flags)
 143#define PXA25X_PBUS95_CKEN(dev_id, con_id, bit, mult_hp, div_hp, delay) \
 144        PXA25X_CKEN(dev_id, con_id, pxa25x_pbus95_parents, mult_hp,     \
 145                    div_hp, bit, NULL, 0)
 146#define PXA25X_PBUS147_CKEN(dev_id, con_id, bit, mult_hp, div_hp, delay)\
 147        PXA25X_CKEN(dev_id, con_id, pxa25x_pbus147_parents, mult_hp,    \
 148                    div_hp, bit, NULL, 0)
 149#define PXA25X_OSC3_CKEN(dev_id, con_id, bit, mult_hp, div_hp, delay)   \
 150        PXA25X_CKEN(dev_id, con_id, pxa25x_osc3_parents, mult_hp,       \
 151                    div_hp, bit, NULL, 0)
 152
 153#define PXA25X_CKEN_1RATE(dev_id, con_id, bit, parents, delay)          \
 154        PXA_CKEN_1RATE(dev_id, con_id, bit, parents,                    \
 155                       CKEN, CKEN_ ## bit, 0)
 156#define PXA25X_CKEN_1RATE_AO(dev_id, con_id, bit, parents, delay)       \
 157        PXA_CKEN_1RATE(dev_id, con_id, bit, parents,                    \
 158                       CKEN, CKEN_ ## bit, CLK_IGNORE_UNUSED)
 159
 160static struct desc_clk_cken pxa25x_clocks[] __initdata = {
 161        PXA25X_PBUS95_CKEN("pxa2xx-mci.0", NULL, MMC, 1, 5, 0),
 162        PXA25X_PBUS95_CKEN("pxa2xx-i2c.0", NULL, I2C, 1, 3, 0),
 163        PXA25X_PBUS95_CKEN("pxa2xx-ir", "FICPCLK", FICP, 1, 2, 0),
 164        PXA25X_PBUS95_CKEN("pxa25x-udc", NULL, USB, 1, 2, 5),
 165        PXA25X_PBUS147_CKEN("pxa2xx-uart.0", NULL, FFUART, 1, 10, 1),
 166        PXA25X_PBUS147_CKEN("pxa2xx-uart.1", NULL, BTUART, 1, 10, 1),
 167        PXA25X_PBUS147_CKEN("pxa2xx-uart.2", NULL, STUART, 1, 10, 1),
 168        PXA25X_PBUS147_CKEN("pxa2xx-uart.3", NULL, HWUART, 1, 10, 1),
 169        PXA25X_PBUS147_CKEN("pxa2xx-i2s", NULL, I2S, 1, 10, 0),
 170        PXA25X_PBUS147_CKEN(NULL, "AC97CLK", AC97, 1, 12, 0),
 171        PXA25X_OSC3_CKEN("pxa25x-ssp.0", NULL, SSP, 1, 1, 0),
 172        PXA25X_OSC3_CKEN("pxa25x-nssp.1", NULL, NSSP, 1, 1, 0),
 173        PXA25X_OSC3_CKEN("pxa25x-nssp.2", NULL, ASSP, 1, 1, 0),
 174        PXA25X_OSC3_CKEN("pxa25x-pwm.0", NULL, PWM0, 1, 1, 0),
 175        PXA25X_OSC3_CKEN("pxa25x-pwm.1", NULL, PWM1, 1, 1, 0),
 176
 177        PXA25X_CKEN_1RATE("pxa2xx-fb", NULL, LCD, clk_pxa25x_memory_parents, 0),
 178        PXA25X_CKEN_1RATE_AO("pxa2xx-pcmcia", NULL, MEMC,
 179                             clk_pxa25x_memory_parents, 0),
 180};
 181
 182/*
 183 * In this table, PXA25x_CCCR(N2, M, L) has the following meaning, where :
 184 *   - freq_cpll = n * m * L * 3.6864 MHz
 185 *   - n = N2 / 2
 186 *   - m = 2^(M - 1), where 1 <= M <= 3
 187 *   - l = L_clk_mult[L], ie. { 0, 27, 32, 36, 40, 45, 0, }[L]
 188 */
 189static struct pxa2xx_freq pxa25x_freqs[] = {
 190        /* CPU  MEMBUS  CCCR                  DIV2 CCLKCFG      */
 191        { 99532800, 99500, PXA25x_CCCR(2,  1, 1),  1, PXA25x_CLKCFG(1)},
 192        {199065600, 99500, PXA25x_CCCR(4,  1, 1),  0, PXA25x_CLKCFG(1)},
 193        {298598400, 99500, PXA25x_CCCR(3,  2, 1),  0, PXA25x_CLKCFG(1)},
 194        {398131200, 99500, PXA25x_CCCR(4,  2, 1),  0, PXA25x_CLKCFG(1)},
 195};
 196
 197static u8 clk_pxa25x_core_get_parent(struct clk_hw *hw)
 198{
 199        unsigned long clkcfg;
 200        unsigned int t;
 201
 202        asm("mrc\tp14, 0, %0, c6, c0, 0" : "=r" (clkcfg));
 203        t  = clkcfg & (1 << 0);
 204        if (t)
 205                return PXA_CORE_TURBO;
 206        return PXA_CORE_RUN;
 207}
 208
 209static int clk_pxa25x_core_set_parent(struct clk_hw *hw, u8 index)
 210{
 211        if (index > PXA_CORE_TURBO)
 212                return -EINVAL;
 213
 214        pxa2xx_core_turbo_switch(index == PXA_CORE_TURBO);
 215
 216        return 0;
 217}
 218
 219static int clk_pxa25x_core_determine_rate(struct clk_hw *hw,
 220                                          struct clk_rate_request *req)
 221{
 222        return __clk_mux_determine_rate(hw, req);
 223}
 224
 225PARENTS(clk_pxa25x_core) = { "run", "cpll" };
 226MUX_OPS(clk_pxa25x_core, "core", CLK_SET_RATE_PARENT);
 227
 228static unsigned long clk_pxa25x_run_get_rate(struct clk_hw *hw,
 229                                             unsigned long parent_rate)
 230{
 231        unsigned long cccr = readl(CCCR);
 232        unsigned int n2 = N2_clk_mult[(cccr >> 7) & 0x07];
 233
 234        return (parent_rate / n2) * 2;
 235}
 236PARENTS(clk_pxa25x_run) = { "cpll" };
 237RATE_RO_OPS(clk_pxa25x_run, "run");
 238
 239static unsigned long clk_pxa25x_cpll_get_rate(struct clk_hw *hw,
 240        unsigned long parent_rate)
 241{
 242        unsigned long clkcfg, cccr = readl(CCCR);
 243        unsigned int l, m, n2, t;
 244
 245        asm("mrc\tp14, 0, %0, c6, c0, 0" : "=r" (clkcfg));
 246        t = clkcfg & (1 << 0);
 247        l  =  L_clk_mult[(cccr >> 0) & 0x1f];
 248        m = M_clk_mult[(cccr >> 5) & 0x03];
 249        n2 = N2_clk_mult[(cccr >> 7) & 0x07];
 250
 251        return m * l * n2 * parent_rate / 2;
 252}
 253
 254static int clk_pxa25x_cpll_determine_rate(struct clk_hw *hw,
 255                                          struct clk_rate_request *req)
 256{
 257        return pxa2xx_determine_rate(req, pxa25x_freqs,
 258                                     ARRAY_SIZE(pxa25x_freqs));
 259}
 260
 261static int clk_pxa25x_cpll_set_rate(struct clk_hw *hw, unsigned long rate,
 262                                    unsigned long parent_rate)
 263{
 264        int i;
 265
 266        pr_debug("%s(rate=%lu parent_rate=%lu)\n", __func__, rate, parent_rate);
 267        for (i = 0; i < ARRAY_SIZE(pxa25x_freqs); i++)
 268                if (pxa25x_freqs[i].cpll == rate)
 269                        break;
 270
 271        if (i >= ARRAY_SIZE(pxa25x_freqs))
 272                return -EINVAL;
 273
 274        pxa2xx_cpll_change(&pxa25x_freqs[i], mdrefr_dri, MDREFR, CCCR);
 275
 276        return 0;
 277}
 278PARENTS(clk_pxa25x_cpll) = { "osc_3_6864mhz" };
 279RATE_OPS(clk_pxa25x_cpll, "cpll");
 280
 281static void __init pxa25x_register_core(void)
 282{
 283        clkdev_pxa_register(CLK_NONE, "cpll", NULL,
 284                            clk_register_clk_pxa25x_cpll());
 285        clkdev_pxa_register(CLK_NONE, "run", NULL,
 286                            clk_register_clk_pxa25x_run());
 287        clkdev_pxa_register(CLK_CORE, "core", NULL,
 288                            clk_register_clk_pxa25x_core());
 289}
 290
 291static void __init pxa25x_register_plls(void)
 292{
 293        clk_register_fixed_rate(NULL, "osc_3_6864mhz", NULL,
 294                                CLK_GET_RATE_NOCACHE, 3686400);
 295        clk_register_fixed_rate(NULL, "osc_32_768khz", NULL,
 296                                CLK_GET_RATE_NOCACHE, 32768);
 297        clk_register_fixed_rate(NULL, "clk_dummy", NULL, 0, 0);
 298        clk_register_fixed_factor(NULL, "ppll_95_85mhz", "osc_3_6864mhz",
 299                                  0, 26, 1);
 300        clk_register_fixed_factor(NULL, "ppll_147_46mhz", "osc_3_6864mhz",
 301                                  0, 40, 1);
 302}
 303
 304static void __init pxa25x_base_clocks_init(void)
 305{
 306        pxa25x_register_plls();
 307        pxa25x_register_core();
 308        clkdev_pxa_register(CLK_NONE, "system_bus", NULL,
 309                            clk_register_clk_pxa25x_memory());
 310}
 311
 312#define DUMMY_CLK(_con_id, _dev_id, _parent) \
 313        { .con_id = _con_id, .dev_id = _dev_id, .parent = _parent }
 314struct dummy_clk {
 315        const char *con_id;
 316        const char *dev_id;
 317        const char *parent;
 318};
 319static struct dummy_clk dummy_clks[] __initdata = {
 320        DUMMY_CLK(NULL, "pxa25x-gpio", "osc_32_768khz"),
 321        DUMMY_CLK(NULL, "pxa26x-gpio", "osc_32_768khz"),
 322        DUMMY_CLK("GPIO11_CLK", NULL, "osc_3_6864mhz"),
 323        DUMMY_CLK("GPIO12_CLK", NULL, "osc_32_768khz"),
 324        DUMMY_CLK(NULL, "sa1100-rtc", "osc_32_768khz"),
 325        DUMMY_CLK("OSTIMER0", NULL, "osc_3_6864mhz"),
 326        DUMMY_CLK("UARTCLK", "pxa2xx-ir", "STUART"),
 327};
 328
 329static void __init pxa25x_dummy_clocks_init(void)
 330{
 331        struct clk *clk;
 332        struct dummy_clk *d;
 333        const char *name;
 334        int i;
 335
 336        /*
 337         * All pinctrl logic has been wiped out of the clock driver, especially
 338         * for gpio11 and gpio12 outputs. Machine code should ensure proper pin
 339         * control (ie. pxa2xx_mfp_config() invocation).
 340         */
 341        for (i = 0; i < ARRAY_SIZE(dummy_clks); i++) {
 342                d = &dummy_clks[i];
 343                name = d->dev_id ? d->dev_id : d->con_id;
 344                clk = clk_register_fixed_factor(NULL, name, d->parent, 0, 1, 1);
 345                clk_register_clkdev(clk, d->con_id, d->dev_id);
 346        }
 347}
 348
 349int __init pxa25x_clocks_init(void)
 350{
 351        pxa25x_base_clocks_init();
 352        pxa25x_dummy_clocks_init();
 353        return clk_pxa_cken_init(pxa25x_clocks, ARRAY_SIZE(pxa25x_clocks));
 354}
 355
 356static void __init pxa25x_dt_clocks_init(struct device_node *np)
 357{
 358        pxa25x_clocks_init();
 359        clk_pxa_dt_common_init(np);
 360}
 361CLK_OF_DECLARE(pxa25x_clks, "marvell,pxa250-core-clocks",
 362               pxa25x_dt_clocks_init);
 363