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