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