drivers/clk/mvebu/armada-37xx-periph.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Marvell Armada 37xx SoC Peripheral clocks
   4  *
   5  * Copyright (C) 2016 Marvell
   6  *
   7  * Gregory CLEMENT <gregory.clement@free-electrons.com>
   8  *
   9  * Most of the peripheral clocks can be modelled like this:
  10  *             _____    _______    _______
  11  * TBG-A-P  --|     |  |       |  |       |   ______
  12  * TBG-B-P  --| Mux |--| /div1 |--| /div2 |--| Gate |--> perip_clk
  13  * TBG-A-S  --|     |  |       |  |       |  |______|
  14  * TBG-B-S  --|_____|  |_______|  |_______|
  15  *
  16  * However some clocks may use only one or two block or and use the
  17  * xtal clock as parent.
  18  */
  19
  20 #include <linux/clk-provider.h>
  21 #include <linux/io.h>
  22 #include <linux/mfd/syscon.h>
  23 #include <linux/of.h>
  24 #include <linux/of_device.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/regmap.h>
  27 #include <linux/slab.h>
  28
  29 #define TBG_SEL         0x0
  30 #define DIV_SEL0        0x4
  31 #define DIV_SEL1        0x8
  32 #define DIV_SEL2        0xC
  33 #define CLK_SEL         0x10
  34 #define CLK_DIS         0x14
  35
  36 #define  ARMADA_37XX_DVFS_LOAD_1 1
  37 #define LOAD_LEVEL_NR   4
  38
  39 #define ARMADA_37XX_NB_L0L1     0x18
  40 #define ARMADA_37XX_NB_L2L3     0x1C
  41 #define         ARMADA_37XX_NB_TBG_DIV_OFF      13
  42 #define         ARMADA_37XX_NB_TBG_DIV_MASK     0x7
  43 #define         ARMADA_37XX_NB_CLK_SEL_OFF      11
  44 #define         ARMADA_37XX_NB_CLK_SEL_MASK     0x1
  45 #define         ARMADA_37XX_NB_TBG_SEL_OFF      9
  46 #define         ARMADA_37XX_NB_TBG_SEL_MASK     0x3
  47 #define         ARMADA_37XX_NB_CONFIG_SHIFT     16
  48 #define ARMADA_37XX_NB_DYN_MOD  0x24
  49 #define         ARMADA_37XX_NB_DFS_EN   31
  50 #define ARMADA_37XX_NB_CPU_LOAD 0x30
  51 #define         ARMADA_37XX_NB_CPU_LOAD_MASK    0x3
  52 #define         ARMADA_37XX_DVFS_LOAD_0         0
  53 #define         ARMADA_37XX_DVFS_LOAD_1         1
  54 #define         ARMADA_37XX_DVFS_LOAD_2         2
  55 #define         ARMADA_37XX_DVFS_LOAD_3         3
  56
  57 struct clk_periph_driver_data {
  58         struct clk_hw_onecell_data *hw_data;
  59         spinlock_t lock;
  60         void __iomem *reg;
  61
  62         /* Storage registers for suspend/resume operations */
  63         u32 tbg_sel;
  64         u32 div_sel0;
  65         u32 div_sel1;
  66         u32 div_sel2;
  67         u32 clk_sel;
  68         u32 clk_dis;
  69 };
  70
  71 struct clk_double_div {
  72         struct clk_hw hw;
  73         void __iomem *reg1;
  74         u8 shift1;
  75         void __iomem *reg2;
  76         u8 shift2;
  77 };
  78
  79 struct clk_pm_cpu {
  80         struct clk_hw hw;
  81         void __iomem *reg_mux;
  82         u8 shift_mux;
  83         u32 mask_mux;
  84         void __iomem *reg_div;
  85         u8 shift_div;
  86         struct regmap *nb_pm_base;
  87 };
  88
  89 #define to_clk_double_div(_hw) container_of(_hw, struct clk_double_div, hw)
  90 #define to_clk_pm_cpu(_hw) container_of(_hw, struct clk_pm_cpu, hw)
  91
  92 struct clk_periph_data {
  93         const char *name;
  94         const char * const *parent_names;
  95         int num_parents;
  96         struct clk_hw *mux_hw;
  97         struct clk_hw *rate_hw;
  98         struct clk_hw *gate_hw;
  99         struct clk_hw *muxrate_hw;
 100         bool is_double_div;
 101 };
 102
 103 static const struct clk_div_table clk_table6[] = {
 104         { .val = 1, .div = 1, },
 105         { .val = 2, .div = 2, },
 106         { .val = 3, .div = 3, },
 107         { .val = 4, .div = 4, },
 108         { .val = 5, .div = 5, },
 109         { .val = 6, .div = 6, },
 110         { .val = 0, .div = 0, }, /* last entry */
 111 };
 112
 113 static const struct clk_div_table clk_table1[] = {
 114         { .val = 0, .div = 1, },
 115         { .val = 1, .div = 2, },
 116         { .val = 0, .div = 0, }, /* last entry */
 117 };
 118
 119 static const struct clk_div_table clk_table2[] = {
 120         { .val = 0, .div = 2, },
 121         { .val = 1, .div = 4, },
 122         { .val = 0, .div = 0, }, /* last entry */
 123 };
 124
 125 static const struct clk_ops clk_double_div_ops;
 126 static const struct clk_ops clk_pm_cpu_ops;
 127
 128 #define PERIPH_GATE(_name, _bit)                \
 129 struct clk_gate gate_##_name = {                \
 130         .reg = (void *)CLK_DIS,                 \
 131         .bit_idx = _bit,                        \
 132         .hw.init = &(struct clk_init_data){     \
 133                 .ops =  &clk_gate_ops,          \
 134         }                                       \
 135 };
 136
 137 #define PERIPH_MUX(_name, _shift)               \
 138 struct clk_mux mux_##_name = {                  \
 139         .reg = (void *)TBG_SEL,                 \
 140         .shift = _shift,                        \
 141         .mask = 3,                              \
 142         .hw.init = &(struct clk_init_data){     \
 143                 .ops =  &clk_mux_ro_ops,        \
 144         }                                       \
 145 };
 146
 147 #define PERIPH_DOUBLEDIV(_name, _reg1, _reg2, _shift1, _shift2) \
 148 struct clk_double_div rate_##_name = {          \
 149         .reg1 = (void *)_reg1,                  \
 150         .reg2 = (void *)_reg2,                  \
 151         .shift1 = _shift1,                      \
 152         .shift2 = _shift2,                      \
 153         .hw.init = &(struct clk_init_data){     \
 154                 .ops =  &clk_double_div_ops,    \
 155         }                                       \
 156 };
 157
 158 #define PERIPH_DIV(_name, _reg, _shift, _table) \
 159 struct clk_divider rate_##_name = {             \
 160         .reg = (void *)_reg,                    \
 161         .table = _table,                        \
 162         .shift = _shift,                        \
 163         .hw.init = &(struct clk_init_data){     \
 164                 .ops =  &clk_divider_ro_ops,    \
 165         }                                       \
 166 };
 167
 168 #define PERIPH_PM_CPU(_name, _shift1, _reg, _shift2)    \
 169 struct clk_pm_cpu muxrate_##_name = {           \
 170         .reg_mux = (void *)TBG_SEL,             \
 171         .mask_mux = 3,                          \
 172         .shift_mux = _shift1,                   \
 173         .reg_div = (void *)_reg,                \
 174         .shift_div = _shift2,                   \
 175         .hw.init = &(struct clk_init_data){     \
 176                 .ops =  &clk_pm_cpu_ops,        \
 177         }                                       \
 178 };
 179
 180 #define PERIPH_CLK_FULL_DD(_name, _bit, _shift, _reg1, _reg2, _shift1, _shift2)\
 181 static PERIPH_GATE(_name, _bit);                            \
 182 static PERIPH_MUX(_name, _shift);                           \
 183 static PERIPH_DOUBLEDIV(_name, _reg1, _reg2, _shift1, _shift2);
 184
 185 #define PERIPH_CLK_FULL(_name, _bit, _shift, _reg, _shift1, _table)     \
 186 static PERIPH_GATE(_name, _bit);                            \
 187 static PERIPH_MUX(_name, _shift);                           \
 188 static PERIPH_DIV(_name, _reg, _shift1, _table);
 189
 190 #define PERIPH_CLK_GATE_DIV(_name, _bit,  _reg, _shift, _table) \
 191 static PERIPH_GATE(_name, _bit);                        \
 192 static PERIPH_DIV(_name, _reg, _shift, _table);
 193
 194 #define PERIPH_CLK_MUX_DD(_name, _shift, _reg1, _reg2, _shift1, _shift2)\
 195 static PERIPH_MUX(_name, _shift);                           \
 196 static PERIPH_DOUBLEDIV(_name, _reg1, _reg2, _shift1, _shift2);
 197
 198 #define REF_CLK_FULL(_name)                             \
 199         { .name = #_name,                               \
 200           .parent_names = (const char *[]){ "TBG-A-P",  \
 201               "TBG-B-P", "TBG-A-S", "TBG-B-S"},         \
 202           .num_parents = 4,                             \
 203           .mux_hw = &mux_##_name.hw,                    \
 204           .gate_hw = &gate_##_name.hw,                  \
 205           .rate_hw = &rate_##_name.hw,                  \
 206         }
 207
 208 #define REF_CLK_FULL_DD(_name)                          \
 209         { .name = #_name,                               \
 210           .parent_names = (const char *[]){ "TBG-A-P",  \
 211               "TBG-B-P", "TBG-A-S", "TBG-B-S"},         \
 212           .num_parents = 4,                             \
 213           .mux_hw = &mux_##_name.hw,                    \
 214           .gate_hw = &gate_##_name.hw,                  \
 215           .rate_hw = &rate_##_name.hw,                  \
 216           .is_double_div = true,                        \
 217         }
 218
 219 #define REF_CLK_GATE(_name, _parent_name)                       \
 220         { .name = #_name,                                       \
 221           .parent_names = (const char *[]){ _parent_name},      \
 222           .num_parents = 1,                                     \
 223           .gate_hw = &gate_##_name.hw,                          \
 224         }
 225
 226 #define REF_CLK_GATE_DIV(_name, _parent_name)                   \
 227         { .name = #_name,                                       \
 228           .parent_names = (const char *[]){ _parent_name},      \
 229           .num_parents = 1,                                     \
 230           .gate_hw = &gate_##_name.hw,                          \
 231           .rate_hw = &rate_##_name.hw,                          \
 232         }
 233
 234 #define REF_CLK_PM_CPU(_name)                           \
 235         { .name = #_name,                               \
 236           .parent_names = (const char *[]){ "TBG-A-P",  \
 237               "TBG-B-P", "TBG-A-S", "TBG-B-S"},         \
 238           .num_parents = 4,                             \
 239           .muxrate_hw = &muxrate_##_name.hw,            \
 240         }
 241
 242 #define REF_CLK_MUX_DD(_name)                           \
 243         { .name = #_name,                               \
 244           .parent_names = (const char *[]){ "TBG-A-P",  \
 245               "TBG-B-P", "TBG-A-S", "TBG-B-S"},         \
 246           .num_parents = 4,                             \
 247           .mux_hw = &mux_##_name.hw,                    \
 248           .rate_hw = &rate_##_name.hw,                  \
 249           .is_double_div = true,                        \
 250         }
 251
 252 /* NB periph clocks */
 253 PERIPH_CLK_FULL_DD(mmc, 2, 0, DIV_SEL2, DIV_SEL2, 16, 13);
 254 PERIPH_CLK_FULL_DD(sata_host, 3, 2, DIV_SEL2, DIV_SEL2, 10, 7);
 255 PERIPH_CLK_FULL_DD(sec_at, 6, 4, DIV_SEL1, DIV_SEL1, 3, 0);
 256 PERIPH_CLK_FULL_DD(sec_dap, 7, 6, DIV_SEL1, DIV_SEL1, 9, 6);
 257 PERIPH_CLK_FULL_DD(tscem, 8, 8, DIV_SEL1, DIV_SEL1, 15, 12);
 258 PERIPH_CLK_FULL(tscem_tmx, 10, 10, DIV_SEL1, 18, clk_table6);
 259 static PERIPH_GATE(avs, 11);
 260 PERIPH_CLK_FULL_DD(pwm, 13, 14, DIV_SEL0, DIV_SEL0, 3, 0);
 261 PERIPH_CLK_FULL_DD(sqf, 12, 12, DIV_SEL1, DIV_SEL1, 27, 24);
 262 static PERIPH_GATE(i2c_2, 16);
 263 static PERIPH_GATE(i2c_1, 17);
 264 PERIPH_CLK_GATE_DIV(ddr_phy, 19, DIV_SEL0, 18, clk_table2);
 265 PERIPH_CLK_FULL_DD(ddr_fclk, 21, 16, DIV_SEL0, DIV_SEL0, 15, 12);
 266 PERIPH_CLK_FULL(trace, 22, 18, DIV_SEL0, 20, clk_table6);
 267 PERIPH_CLK_FULL(counter, 23, 20, DIV_SEL0, 23, clk_table6);
 268 PERIPH_CLK_FULL_DD(eip97, 24, 24, DIV_SEL2, DIV_SEL2, 22, 19);
 269 static PERIPH_PM_CPU(cpu, 22, DIV_SEL0, 28);
 270
 271 static struct clk_periph_data data_nb[] = {
 272         REF_CLK_FULL_DD(mmc),
 273         REF_CLK_FULL_DD(sata_host),
 274         REF_CLK_FULL_DD(sec_at),
 275         REF_CLK_FULL_DD(sec_dap),
 276         REF_CLK_FULL_DD(tscem),
 277         REF_CLK_FULL(tscem_tmx),
 278         REF_CLK_GATE(avs, "xtal"),
 279         REF_CLK_FULL_DD(sqf),
 280         REF_CLK_FULL_DD(pwm),
 281         REF_CLK_GATE(i2c_2, "xtal"),
 282         REF_CLK_GATE(i2c_1, "xtal"),
 283         REF_CLK_GATE_DIV(ddr_phy, "TBG-A-S"),
 284         REF_CLK_FULL_DD(ddr_fclk),
 285         REF_CLK_FULL(trace),
 286         REF_CLK_FULL(counter),
 287         REF_CLK_FULL_DD(eip97),
 288         REF_CLK_PM_CPU(cpu),
 289         { },
 290 };
 291
 292 /* SB periph clocks */
 293 PERIPH_CLK_MUX_DD(gbe_50, 6, DIV_SEL2, DIV_SEL2, 6, 9);
 294 PERIPH_CLK_MUX_DD(gbe_core, 8, DIV_SEL1, DIV_SEL1, 18, 21);
 295 PERIPH_CLK_MUX_DD(gbe_125, 10, DIV_SEL1, DIV_SEL1, 6, 9);
 296 static PERIPH_GATE(gbe1_50, 0);
 297 static PERIPH_GATE(gbe0_50, 1);
 298 static PERIPH_GATE(gbe1_125, 2);
 299 static PERIPH_GATE(gbe0_125, 3);
 300 PERIPH_CLK_GATE_DIV(gbe1_core, 4, DIV_SEL1, 13, clk_table1);
 301 PERIPH_CLK_GATE_DIV(gbe0_core, 5, DIV_SEL1, 14, clk_table1);
 302 PERIPH_CLK_GATE_DIV(gbe_bm, 12, DIV_SEL1, 0, clk_table1);
 303 PERIPH_CLK_FULL_DD(sdio, 11, 14, DIV_SEL0, DIV_SEL0, 3, 6);
 304 PERIPH_CLK_FULL_DD(usb32_usb2_sys, 16, 16, DIV_SEL0, DIV_SEL0, 9, 12);
 305 PERIPH_CLK_FULL_DD(usb32_ss_sys, 17, 18, DIV_SEL0, DIV_SEL0, 15, 18);
 306
 307 static struct clk_periph_data data_sb[] = {
 308         REF_CLK_MUX_DD(gbe_50),
 309         REF_CLK_MUX_DD(gbe_core),
 310         REF_CLK_MUX_DD(gbe_125),
 311         REF_CLK_GATE(gbe1_50, "gbe_50"),
 312         REF_CLK_GATE(gbe0_50, "gbe_50"),
 313         REF_CLK_GATE(gbe1_125, "gbe_125"),
 314         REF_CLK_GATE(gbe0_125, "gbe_125"),
 315         REF_CLK_GATE_DIV(gbe1_core, "gbe_core"),
 316         REF_CLK_GATE_DIV(gbe0_core, "gbe_core"),
 317         REF_CLK_GATE_DIV(gbe_bm, "gbe_core"),
 318         REF_CLK_FULL_DD(sdio),
 319         REF_CLK_FULL_DD(usb32_usb2_sys),
 320         REF_CLK_FULL_DD(usb32_ss_sys),
 321         { },
 322 };
 323
 324 static unsigned int get_div(void __iomem *reg, int shift)
 325 {
 326         u32 val;
 327
 328         val = (readl(reg) >> shift) & 0x7;
 329         if (val > 6)
 330                 return 0;
 331         return val;
 332 }
 333
 334 static unsigned long clk_double_div_recalc_rate(struct clk_hw *hw,
 335                                                 unsigned long parent_rate)
 336 {
 337         struct clk_double_div *double_div = to_clk_double_div(hw);
 338         unsigned int div;
 339
 340         div = get_div(double_div->reg1, double_div->shift1);
 341         div *= get_div(double_div->reg2, double_div->shift2);
 342
 343         return DIV_ROUND_UP_ULL((u64)parent_rate, div);
 344 }
 345
 346 static const struct clk_ops clk_double_div_ops = {
 347         .recalc_rate = clk_double_div_recalc_rate,
 348 };
 349
 350 static void armada_3700_pm_dvfs_update_regs(unsigned int load_level,
 351                                             unsigned int *reg,
 352                                             unsigned int *offset)
 353 {
 354         if (load_level <= ARMADA_37XX_DVFS_LOAD_1)
 355                 *reg = ARMADA_37XX_NB_L0L1;
 356         else
 357                 *reg = ARMADA_37XX_NB_L2L3;
 358
 359         if (load_level == ARMADA_37XX_DVFS_LOAD_0 ||
 360             load_level ==  ARMADA_37XX_DVFS_LOAD_2)
 361                 *offset += ARMADA_37XX_NB_CONFIG_SHIFT;
 362 }
 363
 364 static bool armada_3700_pm_dvfs_is_enabled(struct regmap *base)
 365 {
 366         unsigned int val, reg = ARMADA_37XX_NB_DYN_MOD;
 367
 368         if (IS_ERR(base))
 369                 return false;
 370
 371         regmap_read(base, reg, &val);
 372
 373         return !!(val & BIT(ARMADA_37XX_NB_DFS_EN));
 374 }
 375
 376 static unsigned int armada_3700_pm_dvfs_get_cpu_div(struct regmap *base)
 377 {
 378         unsigned int reg = ARMADA_37XX_NB_CPU_LOAD;
 379         unsigned int offset = ARMADA_37XX_NB_TBG_DIV_OFF;
 380         unsigned int load_level, div;
 381
 382         /*
 383          * This function is always called after the function
 384          * armada_3700_pm_dvfs_is_enabled, so no need to check again
 385          * if the base is valid.
 386          */
 387         regmap_read(base, reg, &load_level);
 388
 389         /*
 390          * The register and the offset inside this register accessed to
 391          * read the current divider depend on the load level
 392          */
 393         load_level &= ARMADA_37XX_NB_CPU_LOAD_MASK;
 394         armada_3700_pm_dvfs_update_regs(load_level, &reg, &offset);
 395
 396         regmap_read(base, reg, &div);
 397
 398         return (div >> offset) & ARMADA_37XX_NB_TBG_DIV_MASK;
 399 }
 400
 401 static unsigned int armada_3700_pm_dvfs_get_cpu_parent(struct regmap *base)
 402 {
 403         unsigned int reg = ARMADA_37XX_NB_CPU_LOAD;
 404         unsigned int offset = ARMADA_37XX_NB_TBG_SEL_OFF;
 405         unsigned int load_level, sel;
 406
 407         /*
 408          * This function is always called after the function
 409          * armada_3700_pm_dvfs_is_enabled, so no need to check again
 410          * if the base is valid
 411          */
 412         regmap_read(base, reg, &load_level);
 413
 414         /*
 415          * The register and the offset inside this register accessed to
 416          * read the current divider depend on the load level
 417          */
 418         load_level &= ARMADA_37XX_NB_CPU_LOAD_MASK;
 419         armada_3700_pm_dvfs_update_regs(load_level, &reg, &offset);
 420
 421         regmap_read(base, reg, &sel);
 422
 423         return (sel >> offset) & ARMADA_37XX_NB_TBG_SEL_MASK;
 424 }
 425
 426 static u8 clk_pm_cpu_get_parent(struct clk_hw *hw)
 427 {
 428         struct clk_pm_cpu *pm_cpu = to_clk_pm_cpu(hw);
 429         u32 val;
 430
 431         if (armada_3700_pm_dvfs_is_enabled(pm_cpu->nb_pm_base)) {
 432                 val = armada_3700_pm_dvfs_get_cpu_parent(pm_cpu->nb_pm_base);
 433         } else {
 434                 val = readl(pm_cpu->reg_mux) >> pm_cpu->shift_mux;
 435                 val &= pm_cpu->mask_mux;
 436         }
 437
 438         return val;
 439 }
 440
 441 static int clk_pm_cpu_set_parent(struct clk_hw *hw, u8 index)
 442 {
 443         struct clk_pm_cpu *pm_cpu = to_clk_pm_cpu(hw);
 444         struct regmap *base = pm_cpu->nb_pm_base;
 445         int load_level;
 446
 447         /*
 448          * We set the clock parent only if the DVFS is available but
 449          * not enabled.
 450          */
 451         if (IS_ERR(base) || armada_3700_pm_dvfs_is_enabled(base))
 452                 return -EINVAL;
 453
 454         /* Set the parent clock for all the load level */
 455         for (load_level = 0; load_level < LOAD_LEVEL_NR; load_level++) {
 456                 unsigned int reg, mask,  val,
 457                         offset = ARMADA_37XX_NB_TBG_SEL_OFF;
 458
 459                 armada_3700_pm_dvfs_update_regs(load_level, &reg, &offset);
 460
 461                 val = index << offset;
 462                 mask = ARMADA_37XX_NB_TBG_SEL_MASK << offset;
 463                 regmap_update_bits(base, reg, mask, val);
 464         }
 465         return 0;
 466 }
 467
 468 static unsigned long clk_pm_cpu_recalc_rate(struct clk_hw *hw,
 469                                             unsigned long parent_rate)
 470 {
 471         struct clk_pm_cpu *pm_cpu = to_clk_pm_cpu(hw);
 472         unsigned int div;
 473
 474         if (armada_3700_pm_dvfs_is_enabled(pm_cpu->nb_pm_base))
 475                 div = armada_3700_pm_dvfs_get_cpu_div(pm_cpu->nb_pm_base);
 476         else
 477                 div = get_div(pm_cpu->reg_div, pm_cpu->shift_div);
 478         return DIV_ROUND_UP_ULL((u64)parent_rate, div);
 479 }
 480
 481 static long clk_pm_cpu_round_rate(struct clk_hw *hw, unsigned long rate,
 482                                   unsigned long *parent_rate)
 483 {
 484         struct clk_pm_cpu *pm_cpu = to_clk_pm_cpu(hw);
 485         struct regmap *base = pm_cpu->nb_pm_base;
 486         unsigned int div = *parent_rate / rate;
 487         unsigned int load_level;
 488         /* only available when DVFS is enabled */
 489         if (!armada_3700_pm_dvfs_is_enabled(base))
 490                 return -EINVAL;
 491
 492         for (load_level = 0; load_level < LOAD_LEVEL_NR; load_level++) {
 493                 unsigned int reg, val, offset = ARMADA_37XX_NB_TBG_DIV_OFF;
 494
 495                 armada_3700_pm_dvfs_update_regs(load_level, &reg, &offset);
 496
 497                 regmap_read(base, reg, &val);
 498
 499                 val >>= offset;
 500                 val &= ARMADA_37XX_NB_TBG_DIV_MASK;
 501                 if (val == div)
 502                         /*
 503                          * We found a load level matching the target
 504                          * divider, switch to this load level and
 505                          * return.
 506                          */
 507                         return *parent_rate / div;
 508         }
 509
 510         /* We didn't find any valid divider */
 511         return -EINVAL;
 512 }
 513
 514 /*
 515  * Switching the CPU from the L2 or L3 frequencies (300 and 200 Mhz
 516  * respectively) to L0 frequency (1.2 Ghz) requires a significant
 517  * amount of time to let VDD stabilize to the appropriate
 518  * voltage. This amount of time is large enough that it cannot be
 519  * covered by the hardware countdown register. Due to this, the CPU
 520  * might start operating at L0 before the voltage is stabilized,
 521  * leading to CPU stalls.
 522  *
 523  * To work around this problem, we prevent switching directly from the
 524  * L2/L3 frequencies to the L0 frequency, and instead switch to the L1
 525  * frequency in-between. The sequence therefore becomes:
 526  * 1. First switch from L2/L3(200/300MHz) to L1(600MHZ)
 527  * 2. Sleep 20ms for stabling VDD voltage
 528  * 3. Then switch from L1(600MHZ) to L0(1200Mhz).
 529  */
 530 static void clk_pm_cpu_set_rate_wa(unsigned long rate, struct regmap *base)
 531 {
 532         unsigned int cur_level;
 533
 534         if (rate != 1200 * 1000 * 1000)
 535                 return;
 536
 537         regmap_read(base, ARMADA_37XX_NB_CPU_LOAD, &cur_level);
 538         cur_level &= ARMADA_37XX_NB_CPU_LOAD_MASK;
 539         if (cur_level <= ARMADA_37XX_DVFS_LOAD_1)
 540                 return;
 541
 542         regmap_update_bits(base, ARMADA_37XX_NB_CPU_LOAD,
 543                            ARMADA_37XX_NB_CPU_LOAD_MASK,
 544                            ARMADA_37XX_DVFS_LOAD_1);
 545         msleep(20);
 546 }
 547
 548 static int clk_pm_cpu_set_rate(struct clk_hw *hw, unsigned long rate,
 549                                unsigned long parent_rate)
 550 {
 551         struct clk_pm_cpu *pm_cpu = to_clk_pm_cpu(hw);
 552         struct regmap *base = pm_cpu->nb_pm_base;
 553         unsigned int div = parent_rate / rate;
 554         unsigned int load_level;
 555
 556         /* only available when DVFS is enabled */
 557         if (!armada_3700_pm_dvfs_is_enabled(base))
 558                 return -EINVAL;
 559
 560         for (load_level = 0; load_level < LOAD_LEVEL_NR; load_level++) {
 561                 unsigned int reg, mask, val,
 562                         offset = ARMADA_37XX_NB_TBG_DIV_OFF;
 563
 564                 armada_3700_pm_dvfs_update_regs(load_level, &reg, &offset);
 565
 566                 regmap_read(base, reg, &val);
 567                 val >>= offset;
 568                 val &= ARMADA_37XX_NB_TBG_DIV_MASK;
 569
 570                 if (val == div) {
 571                         /*
 572                          * We found a load level matching the target
 573                          * divider, switch to this load level and
 574                          * return.
 575                          */
 576                         reg = ARMADA_37XX_NB_CPU_LOAD;
 577                         mask = ARMADA_37XX_NB_CPU_LOAD_MASK;
 578
 579                         clk_pm_cpu_set_rate_wa(rate, base);
 580
 581                         regmap_update_bits(base, reg, mask, load_level);
 582
 583                         return rate;
 584                 }
 585         }
 586
 587         /* We didn't find any valid divider */
 588         return -EINVAL;
 589 }
 590
 591 static const struct clk_ops clk_pm_cpu_ops = {
 592         .get_parent = clk_pm_cpu_get_parent,
 593         .set_parent = clk_pm_cpu_set_parent,
 594         .round_rate = clk_pm_cpu_round_rate,
 595         .set_rate = clk_pm_cpu_set_rate,
 596         .recalc_rate = clk_pm_cpu_recalc_rate,
 597 };
 598
 599 static const struct of_device_id armada_3700_periph_clock_of_match[] = {
 600         { .compatible = "marvell,armada-3700-periph-clock-nb",
 601           .data = data_nb, },
 602         { .compatible = "marvell,armada-3700-periph-clock-sb",
 603         .data = data_sb, },
 604         { }
 605 };
 606
 607 static int armada_3700_add_composite_clk(const struct clk_periph_data *data,
 608                                          void __iomem *reg, spinlock_t *lock,
 609                                          struct device *dev, struct clk_hw **hw)
 610 {
 611         const struct clk_ops *mux_ops = NULL, *gate_ops = NULL,
 612                 *rate_ops = NULL;
 613         struct clk_hw *mux_hw = NULL, *gate_hw = NULL, *rate_hw = NULL;
 614
 615         if (data->mux_hw) {
 616                 struct clk_mux *mux;
 617
 618                 mux_hw = data->mux_hw;
 619                 mux = to_clk_mux(mux_hw);
 620                 mux->lock = lock;
 621                 mux_ops = mux_hw->init->ops;
 622                 mux->reg = reg + (u64)mux->reg;
 623         }
 624
 625         if (data->gate_hw) {
 626                 struct clk_gate *gate;
 627
 628                 gate_hw = data->gate_hw;
 629                 gate = to_clk_gate(gate_hw);
 630                 gate->lock = lock;
 631                 gate_ops = gate_hw->init->ops;
 632                 gate->reg = reg + (u64)gate->reg;
 633                 gate->flags = CLK_GATE_SET_TO_DISABLE;
 634         }
 635
 636         if (data->rate_hw) {
 637                 rate_hw = data->rate_hw;
 638                 rate_ops = rate_hw->init->ops;
 639                 if (data->is_double_div) {
 640                         struct clk_double_div *rate;
 641
 642                         rate =  to_clk_double_div(rate_hw);
 643                         rate->reg1 = reg + (u64)rate->reg1;
 644                         rate->reg2 = reg + (u64)rate->reg2;
 645                 } else {
 646                         struct clk_divider *rate = to_clk_divider(rate_hw);
 647                         const struct clk_div_table *clkt;
 648                         int table_size = 0;
 649
 650                         rate->reg = reg + (u64)rate->reg;
 651                         for (clkt = rate->table; clkt->div; clkt++)
 652                                 table_size++;
 653                         rate->width = order_base_2(table_size);
 654                         rate->lock = lock;
 655                 }
 656         }
 657
 658         if (data->muxrate_hw) {
 659                 struct clk_pm_cpu *pmcpu_clk;
 660                 struct clk_hw *muxrate_hw = data->muxrate_hw;
 661                 struct regmap *map;
 662
 663                 pmcpu_clk =  to_clk_pm_cpu(muxrate_hw);
 664                 pmcpu_clk->reg_mux = reg + (u64)pmcpu_clk->reg_mux;
 665                 pmcpu_clk->reg_div = reg + (u64)pmcpu_clk->reg_div;
 666
 667                 mux_hw = muxrate_hw;
 668                 rate_hw = muxrate_hw;
 669                 mux_ops = muxrate_hw->init->ops;
 670                 rate_ops = muxrate_hw->init->ops;
 671
 672                 map = syscon_regmap_lookup_by_compatible(
 673                                 "marvell,armada-3700-nb-pm");
 674                 pmcpu_clk->nb_pm_base = map;
 675         }
 676
 677         *hw = clk_hw_register_composite(dev, data->name, data->parent_names,
 678                                         data->num_parents, mux_hw,
 679                                         mux_ops, rate_hw, rate_ops,
 680                                         gate_hw, gate_ops, CLK_IGNORE_UNUSED);
 681
 682         return PTR_ERR_OR_ZERO(*hw);
 683 }
 684
 685 static int __maybe_unused armada_3700_periph_clock_suspend(struct device *dev)
 686 {
 687         struct clk_periph_driver_data *data = dev_get_drvdata(dev);
 688
 689         data->tbg_sel = readl(data->reg + TBG_SEL);
 690         data->div_sel0 = readl(data->reg + DIV_SEL0);
 691         data->div_sel1 = readl(data->reg + DIV_SEL1);
 692         data->div_sel2 = readl(data->reg + DIV_SEL2);
 693         data->clk_sel = readl(data->reg + CLK_SEL);
 694         data->clk_dis = readl(data->reg + CLK_DIS);
 695
 696         return 0;
 697 }
 698
 699 static int __maybe_unused armada_3700_periph_clock_resume(struct device *dev)
 700 {
 701         struct clk_periph_driver_data *data = dev_get_drvdata(dev);
 702
 703         /* Follow the same order than what the Cortex-M3 does (ATF code) */
 704         writel(data->clk_dis, data->reg + CLK_DIS);
 705         writel(data->div_sel0, data->reg + DIV_SEL0);
 706         writel(data->div_sel1, data->reg + DIV_SEL1);
 707         writel(data->div_sel2, data->reg + DIV_SEL2);
 708         writel(data->tbg_sel, data->reg + TBG_SEL);
 709         writel(data->clk_sel, data->reg + CLK_SEL);
 710
 711         return 0;
 712 }
 713
 714 static const struct dev_pm_ops armada_3700_periph_clock_pm_ops = {
 715         SET_SYSTEM_SLEEP_PM_OPS(armada_3700_periph_clock_suspend,
 716                                 armada_3700_periph_clock_resume)
 717 };
 718
 719 static int armada_3700_periph_clock_probe(struct platform_device *pdev)
 720 {
 721         struct clk_periph_driver_data *driver_data;
 722         struct device_node *np = pdev->dev.of_node;
 723         const struct clk_periph_data *data;
 724         struct device *dev = &pdev->dev;
 725         int num_periph = 0, i, ret;
 726         struct resource *res;
 727
 728         data = of_device_get_match_data(dev);
 729         if (!data)
 730                 return -ENODEV;
 731
 732         while (data[num_periph].name)
 733                 num_periph++;
 734
 735         driver_data = devm_kzalloc(dev, sizeof(*driver_data), GFP_KERNEL);
 736         if (!driver_data)
 737                 return -ENOMEM;
 738
 739         driver_data->hw_data = devm_kzalloc(dev,
 740                                             struct_size(driver_data->hw_data,
 741                                                         hws, num_periph),
 742                                             GFP_KERNEL);
 743         if (!driver_data->hw_data)
 744                 return -ENOMEM;
 745         driver_data->hw_data->num = num_periph;
 746
 747         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 748         driver_data->reg = devm_ioremap_resource(dev, res);
 749         if (IS_ERR(driver_data->reg))
 750                 return PTR_ERR(driver_data->reg);
 751
 752         spin_lock_init(&driver_data->lock);
 753
 754         for (i = 0; i < num_periph; i++) {
 755                 struct clk_hw **hw = &driver_data->hw_data->hws[i];
 756                 if (armada_3700_add_composite_clk(&data[i], driver_data->reg,
 757                                                   &driver_data->lock, dev, hw))
 758                         dev_err(dev, "Can't register periph clock %s\n",
 759                                 data[i].name);
 760         }
 761
 762         ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get,
 763                                      driver_data->hw_data);
 764         if (ret) {
 765                 for (i = 0; i < num_periph; i++)
 766                         clk_hw_unregister(driver_data->hw_data->hws[i]);
 767                 return ret;
 768         }
 769
 770         platform_set_drvdata(pdev, driver_data);
 771         return 0;
 772 }
 773
 774 static int armada_3700_periph_clock_remove(struct platform_device *pdev)
 775 {
 776         struct clk_periph_driver_data *data = platform_get_drvdata(pdev);
 777         struct clk_hw_onecell_data *hw_data = data->hw_data;
 778         int i;
 779
 780         of_clk_del_provider(pdev->dev.of_node);
 781
 782         for (i = 0; i < hw_data->num; i++)
 783                 clk_hw_unregister(hw_data->hws[i]);
 784
 785         return 0;
 786 }
 787
 788 static struct platform_driver armada_3700_periph_clock_driver = {
 789         .probe = armada_3700_periph_clock_probe,
 790         .remove = armada_3700_periph_clock_remove,
 791         .driver         = {
 792                 .name   = "marvell-armada-3700-periph-clock",
 793                 .of_match_table = armada_3700_periph_clock_of_match,
 794                 .pm     = &armada_3700_periph_clock_pm_ops,
 795         },
 796 };
 797
 798 builtin_platform_driver(armada_3700_periph_clock_driver);