1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * CS2000 -- CIRRUS LOGIC Fractional-N Clock Synthesizer & Clock Multiplier 4 * 5 * Copyright (C) 2015 Renesas Electronics Corporation 6 * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> 7 */ 8 #include <linux/clk-provider.h> 9 #include <linux/delay.h> 10 #include <linux/clk.h> 11 #include <linux/i2c.h> 12 #include <linux/of_device.h> 13 #include <linux/module.h> 14 15 #define CH_MAX 4 16 #define RATIO_REG_SIZE 4 17 18 #define DEVICE_ID 0x1 19 #define DEVICE_CTRL 0x2 20 #define DEVICE_CFG1 0x3 21 #define DEVICE_CFG2 0x4 22 #define GLOBAL_CFG 0x5 23 #define Ratio_Add(x, nth) (6 + (x * 4) + (nth)) 24 #define Ratio_Val(x, nth) ((x >> (24 - (8 * nth))) & 0xFF) 25 #define Val_Ratio(x, nth) ((x & 0xFF) << (24 - (8 * nth))) 26 #define FUNC_CFG1 0x16 27 #define FUNC_CFG2 0x17 28 29 /* DEVICE_ID */ 30 #define REVISION_MASK (0x7) 31 #define REVISION_B2_B3 (0x4) 32 #define REVISION_C1 (0x6) 33 34 /* DEVICE_CTRL */ 35 #define PLL_UNLOCK (1 << 7) 36 #define AUXOUTDIS (1 << 1) 37 #define CLKOUTDIS (1 << 0) 38 39 /* DEVICE_CFG1 */ 40 #define RSEL(x) (((x) & 0x3) << 3) 41 #define RSEL_MASK RSEL(0x3) 42 #define ENDEV1 (0x1) 43 44 /* DEVICE_CFG2 */ 45 #define AUTORMOD (1 << 3) 46 #define LOCKCLK(x) (((x) & 0x3) << 1) 47 #define LOCKCLK_MASK LOCKCLK(0x3) 48 #define FRACNSRC_MASK (1 << 0) 49 #define FRACNSRC_STATIC (0 << 0) 50 #define FRACNSRC_DYNAMIC (1 << 1) 51 52 /* GLOBAL_CFG */ 53 #define ENDEV2 (0x1) 54 55 /* FUNC_CFG1 */ 56 #define CLKSKIPEN (1 << 7) 57 #define REFCLKDIV(x) (((x) & 0x3) << 3) 58 #define REFCLKDIV_MASK REFCLKDIV(0x3) 59 60 /* FUNC_CFG2 */ 61 #define LFRATIO_MASK (1 << 3) 62 #define LFRATIO_20_12 (0 << 3) 63 #define LFRATIO_12_20 (1 << 3) 64 65 #define CH_SIZE_ERR(ch) ((ch < 0) || (ch >= CH_MAX)) 66 #define hw_to_priv(_hw) container_of(_hw, struct cs2000_priv, hw) 67 #define priv_to_client(priv) (priv->client) 68 #define priv_to_dev(priv) (&(priv_to_client(priv)->dev)) 69 70 #define CLK_IN 0 71 #define REF_CLK 1 72 #define CLK_MAX 2 73 74 struct cs2000_priv { 75 struct clk_hw hw; 76 struct i2c_client *client; 77 struct clk *clk_in; 78 struct clk *ref_clk; 79 80 /* suspend/resume */ 81 unsigned long saved_rate; 82 unsigned long saved_parent_rate; 83 }; 84 85 static const struct of_device_id cs2000_of_match[] = { 86 { .compatible = "cirrus,cs2000-cp", }, 87 {}, 88 }; 89 MODULE_DEVICE_TABLE(of, cs2000_of_match); 90 91 static const struct i2c_device_id cs2000_id[] = { 92 { "cs2000-cp", }, 93 {} 94 }; 95 MODULE_DEVICE_TABLE(i2c, cs2000_id); 96 97 #define cs2000_read(priv, addr) \ 98 i2c_smbus_read_byte_data(priv_to_client(priv), addr) 99 #define cs2000_write(priv, addr, val) \ 100 i2c_smbus_write_byte_data(priv_to_client(priv), addr, val) 101 102 static int cs2000_bset(struct cs2000_priv *priv, u8 addr, u8 mask, u8 val) 103 { 104 s32 data; 105 106 data = cs2000_read(priv, addr); 107 if (data < 0) 108 return data; 109 110 data &= ~mask; 111 data |= (val & mask); 112 113 return cs2000_write(priv, addr, data); 114 } 115 116 static int cs2000_enable_dev_config(struct cs2000_priv *priv, bool enable) 117 { 118 int ret; 119 120 ret = cs2000_bset(priv, DEVICE_CFG1, ENDEV1, 121 enable ? ENDEV1 : 0); 122 if (ret < 0) 123 return ret; 124 125 ret = cs2000_bset(priv, GLOBAL_CFG, ENDEV2, 126 enable ? ENDEV2 : 0); 127 if (ret < 0) 128 return ret; 129 130 ret = cs2000_bset(priv, FUNC_CFG1, CLKSKIPEN, 131 enable ? CLKSKIPEN : 0); 132 if (ret < 0) 133 return ret; 134 135 /* FIXME: for Static ratio mode */ 136 ret = cs2000_bset(priv, FUNC_CFG2, LFRATIO_MASK, 137 LFRATIO_12_20); 138 if (ret < 0) 139 return ret; 140 141 return 0; 142 } 143 144 static int cs2000_clk_in_bound_rate(struct cs2000_priv *priv, 145 u32 rate_in) 146 { 147 u32 val; 148 149 if (rate_in >= 32000000 && rate_in < 56000000) 150 val = 0x0; 151 else if (rate_in >= 16000000 && rate_in < 28000000) 152 val = 0x1; 153 else if (rate_in >= 8000000 && rate_in < 14000000) 154 val = 0x2; 155 else 156 return -EINVAL; 157 158 return cs2000_bset(priv, FUNC_CFG1, 159 REFCLKDIV_MASK, 160 REFCLKDIV(val)); 161 } 162 163 static int cs2000_wait_pll_lock(struct cs2000_priv *priv) 164 { 165 struct device *dev = priv_to_dev(priv); 166 s32 val; 167 unsigned int i; 168 169 for (i = 0; i < 256; i++) { 170 val = cs2000_read(priv, DEVICE_CTRL); 171 if (val < 0) 172 return val; 173 if (!(val & PLL_UNLOCK)) 174 return 0; 175 udelay(1); 176 } 177 178 dev_err(dev, "pll lock failed\n"); 179 180 return -ETIMEDOUT; 181 } 182 183 static int cs2000_clk_out_enable(struct cs2000_priv *priv, bool enable) 184 { 185 /* enable both AUX_OUT, CLK_OUT */ 186 return cs2000_bset(priv, DEVICE_CTRL, 187 (AUXOUTDIS | CLKOUTDIS), 188 enable ? 0 : 189 (AUXOUTDIS | CLKOUTDIS)); 190 } 191 192 static u32 cs2000_rate_to_ratio(u32 rate_in, u32 rate_out) 193 { 194 u64 ratio; 195 196 /* 197 * ratio = rate_out / rate_in * 2^20 198 * 199 * To avoid over flow, rate_out is u64. 200 * The result should be u32. 201 */ 202 ratio = (u64)rate_out << 20; 203 do_div(ratio, rate_in); 204 205 return ratio; 206 } 207 208 static unsigned long cs2000_ratio_to_rate(u32 ratio, u32 rate_in) 209 { 210 u64 rate_out; 211 212 /* 213 * ratio = rate_out / rate_in * 2^20 214 * 215 * To avoid over flow, rate_out is u64. 216 * The result should be u32 or unsigned long. 217 */ 218 219 rate_out = (u64)ratio * rate_in; 220 return rate_out >> 20; 221 } 222 223 static int cs2000_ratio_set(struct cs2000_priv *priv, 224 int ch, u32 rate_in, u32 rate_out) 225 { 226 u32 val; 227 unsigned int i; 228 int ret; 229 230 if (CH_SIZE_ERR(ch)) 231 return -EINVAL; 232 233 val = cs2000_rate_to_ratio(rate_in, rate_out); 234 for (i = 0; i < RATIO_REG_SIZE; i++) { 235 ret = cs2000_write(priv, 236 Ratio_Add(ch, i), 237 Ratio_Val(val, i)); 238 if (ret < 0) 239 return ret; 240 } 241 242 return 0; 243 } 244 245 static u32 cs2000_ratio_get(struct cs2000_priv *priv, int ch) 246 { 247 s32 tmp; 248 u32 val; 249 unsigned int i; 250 251 val = 0; 252 for (i = 0; i < RATIO_REG_SIZE; i++) { 253 tmp = cs2000_read(priv, Ratio_Add(ch, i)); 254 if (tmp < 0) 255 return 0; 256 257 val |= Val_Ratio(tmp, i); 258 } 259 260 return val; 261 } 262 263 static int cs2000_ratio_select(struct cs2000_priv *priv, int ch) 264 { 265 int ret; 266 267 if (CH_SIZE_ERR(ch)) 268 return -EINVAL; 269 270 /* 271 * FIXME 272 * 273 * this driver supports static ratio mode only at this point. 274 */ 275 ret = cs2000_bset(priv, DEVICE_CFG1, RSEL_MASK, RSEL(ch)); 276 if (ret < 0) 277 return ret; 278 279 ret = cs2000_bset(priv, DEVICE_CFG2, 280 (AUTORMOD | LOCKCLK_MASK | FRACNSRC_MASK), 281 (LOCKCLK(ch) | FRACNSRC_STATIC)); 282 if (ret < 0) 283 return ret; 284 285 return 0; 286 } 287 288 static unsigned long cs2000_recalc_rate(struct clk_hw *hw, 289 unsigned long parent_rate) 290 { 291 struct cs2000_priv *priv = hw_to_priv(hw); 292 int ch = 0; /* it uses ch0 only at this point */ 293 u32 ratio; 294 295 ratio = cs2000_ratio_get(priv, ch); 296 297 return cs2000_ratio_to_rate(ratio, parent_rate); 298 } 299 300 static long cs2000_round_rate(struct clk_hw *hw, unsigned long rate, 301 unsigned long *parent_rate) 302 { 303 u32 ratio; 304 305 ratio = cs2000_rate_to_ratio(*parent_rate, rate); 306 307 return cs2000_ratio_to_rate(ratio, *parent_rate); 308 } 309 310 static int __cs2000_set_rate(struct cs2000_priv *priv, int ch, 311 unsigned long rate, unsigned long parent_rate) 312 313 { 314 int ret; 315 316 ret = cs2000_clk_in_bound_rate(priv, parent_rate); 317 if (ret < 0) 318 return ret; 319 320 ret = cs2000_ratio_set(priv, ch, parent_rate, rate); 321 if (ret < 0) 322 return ret; 323 324 ret = cs2000_ratio_select(priv, ch); 325 if (ret < 0) 326 return ret; 327 328 priv->saved_rate = rate; 329 priv->saved_parent_rate = parent_rate; 330 331 return 0; 332 } 333 334 static int cs2000_set_rate(struct clk_hw *hw, 335 unsigned long rate, unsigned long parent_rate) 336 { 337 struct cs2000_priv *priv = hw_to_priv(hw); 338 int ch = 0; /* it uses ch0 only at this point */ 339 340 return __cs2000_set_rate(priv, ch, rate, parent_rate); 341 } 342 343 static int cs2000_set_saved_rate(struct cs2000_priv *priv) 344 { 345 int ch = 0; /* it uses ch0 only at this point */ 346 347 return __cs2000_set_rate(priv, ch, 348 priv->saved_rate, 349 priv->saved_parent_rate); 350 } 351 352 static int cs2000_enable(struct clk_hw *hw) 353 { 354 struct cs2000_priv *priv = hw_to_priv(hw); 355 int ret; 356 357 ret = cs2000_enable_dev_config(priv, true); 358 if (ret < 0) 359 return ret; 360 361 ret = cs2000_clk_out_enable(priv, true); 362 if (ret < 0) 363 return ret; 364 365 ret = cs2000_wait_pll_lock(priv); 366 if (ret < 0) 367 return ret; 368 369 return ret; 370 } 371 372 static void cs2000_disable(struct clk_hw *hw) 373 { 374 struct cs2000_priv *priv = hw_to_priv(hw); 375 376 cs2000_enable_dev_config(priv, false); 377 378 cs2000_clk_out_enable(priv, false); 379 } 380 381 static u8 cs2000_get_parent(struct clk_hw *hw) 382 { 383 /* always return REF_CLK */ 384 return REF_CLK; 385 } 386 387 static const struct clk_ops cs2000_ops = { 388 .get_parent = cs2000_get_parent, 389 .recalc_rate = cs2000_recalc_rate, 390 .round_rate = cs2000_round_rate, 391 .set_rate = cs2000_set_rate, 392 .prepare = cs2000_enable, 393 .unprepare = cs2000_disable, 394 }; 395 396 static int cs2000_clk_get(struct cs2000_priv *priv) 397 { 398 struct device *dev = priv_to_dev(priv); 399 struct clk *clk_in, *ref_clk; 400 401 clk_in = devm_clk_get(dev, "clk_in"); 402 /* not yet provided */ 403 if (IS_ERR(clk_in)) 404 return -EPROBE_DEFER; 405 406 ref_clk = devm_clk_get(dev, "ref_clk"); 407 /* not yet provided */ 408 if (IS_ERR(ref_clk)) 409 return -EPROBE_DEFER; 410 411 priv->clk_in = clk_in; 412 priv->ref_clk = ref_clk; 413 414 return 0; 415 } 416 417 static int cs2000_clk_register(struct cs2000_priv *priv) 418 { 419 struct device *dev = priv_to_dev(priv); 420 struct device_node *np = dev->of_node; 421 struct clk_init_data init; 422 const char *name = np->name; 423 static const char *parent_names[CLK_MAX]; 424 int ch = 0; /* it uses ch0 only at this point */ 425 int rate; 426 int ret; 427 428 of_property_read_string(np, "clock-output-names", &name); 429 430 /* 431 * set default rate as 1/1. 432 * otherwise .set_rate which setup ratio 433 * is never called if user requests 1/1 rate 434 */ 435 rate = clk_get_rate(priv->ref_clk); 436 ret = __cs2000_set_rate(priv, ch, rate, rate); 437 if (ret < 0) 438 return ret; 439 440 parent_names[CLK_IN] = __clk_get_name(priv->clk_in); 441 parent_names[REF_CLK] = __clk_get_name(priv->ref_clk); 442 443 init.name = name; 444 init.ops = &cs2000_ops; 445 init.flags = CLK_SET_RATE_GATE; 446 init.parent_names = parent_names; 447 init.num_parents = ARRAY_SIZE(parent_names); 448 449 priv->hw.init = &init; 450 451 ret = clk_hw_register(dev, &priv->hw); 452 if (ret) 453 return ret; 454 455 ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw); 456 if (ret < 0) { 457 clk_hw_unregister(&priv->hw); 458 return ret; 459 } 460 461 return 0; 462 } 463 464 static int cs2000_version_print(struct cs2000_priv *priv) 465 { 466 struct device *dev = priv_to_dev(priv); 467 s32 val; 468 const char *revision; 469 470 val = cs2000_read(priv, DEVICE_ID); 471 if (val < 0) 472 return val; 473 474 /* CS2000 should be 0x0 */ 475 if (val >> 3) 476 return -EIO; 477 478 switch (val & REVISION_MASK) { 479 case REVISION_B2_B3: 480 revision = "B2 / B3"; 481 break; 482 case REVISION_C1: 483 revision = "C1"; 484 break; 485 default: 486 return -EIO; 487 } 488 489 dev_info(dev, "revision - %s\n", revision); 490 491 return 0; 492 } 493 494 static int cs2000_remove(struct i2c_client *client) 495 { 496 struct cs2000_priv *priv = i2c_get_clientdata(client); 497 struct device *dev = priv_to_dev(priv); 498 struct device_node *np = dev->of_node; 499 500 of_clk_del_provider(np); 501 502 clk_hw_unregister(&priv->hw); 503 504 return 0; 505 } 506 507 static int cs2000_probe(struct i2c_client *client, 508 const struct i2c_device_id *id) 509 { 510 struct cs2000_priv *priv; 511 struct device *dev = &client->dev; 512 int ret; 513 514 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 515 if (!priv) 516 return -ENOMEM; 517 518 priv->client = client; 519 i2c_set_clientdata(client, priv); 520 521 ret = cs2000_clk_get(priv); 522 if (ret < 0) 523 return ret; 524 525 ret = cs2000_clk_register(priv); 526 if (ret < 0) 527 return ret; 528 529 ret = cs2000_version_print(priv); 530 if (ret < 0) 531 goto probe_err; 532 533 return 0; 534 535 probe_err: 536 cs2000_remove(client); 537 538 return ret; 539 } 540 541 static int __maybe_unused cs2000_resume(struct device *dev) 542 { 543 struct cs2000_priv *priv = dev_get_drvdata(dev); 544 545 return cs2000_set_saved_rate(priv); 546 } 547 548 static const struct dev_pm_ops cs2000_pm_ops = { 549 SET_LATE_SYSTEM_SLEEP_PM_OPS(NULL, cs2000_resume) 550 }; 551 552 static struct i2c_driver cs2000_driver = { 553 .driver = { 554 .name = "cs2000-cp", 555 .pm = &cs2000_pm_ops, 556 .of_match_table = cs2000_of_match, 557 }, 558 .probe = cs2000_probe, 559 .remove = cs2000_remove, 560 .id_table = cs2000_id, 561 }; 562 563 module_i2c_driver(cs2000_driver); 564 565 MODULE_DESCRIPTION("CS2000-CP driver"); 566 MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>"); 567 MODULE_LICENSE("GPL v2"); 568