1 /* 2 * Nomadik clock implementation 3 * Copyright (C) 2013 ST-Ericsson AB 4 * License terms: GNU General Public License (GPL) version 2 5 * Author: Linus Walleij <linus.walleij@linaro.org> 6 */ 7 8 #define pr_fmt(fmt) "Nomadik SRC clocks: " fmt 9 10 #include <linux/bitops.h> 11 #include <linux/clk.h> 12 #include <linux/clkdev.h> 13 #include <linux/err.h> 14 #include <linux/io.h> 15 #include <linux/clk-provider.h> 16 #include <linux/of.h> 17 #include <linux/of_address.h> 18 #include <linux/debugfs.h> 19 #include <linux/seq_file.h> 20 #include <linux/spinlock.h> 21 #include <linux/reboot.h> 22 23 /* 24 * The Nomadik clock tree is described in the STN8815A12 DB V4.2 25 * reference manual for the chip, page 94 ff. 26 * Clock IDs are in the STn8815 Reference Manual table 3, page 27. 27 */ 28 29 #define SRC_CR 0x00U 30 #define SRC_CR_T0_ENSEL BIT(15) 31 #define SRC_CR_T1_ENSEL BIT(17) 32 #define SRC_CR_T2_ENSEL BIT(19) 33 #define SRC_CR_T3_ENSEL BIT(21) 34 #define SRC_CR_T4_ENSEL BIT(23) 35 #define SRC_CR_T5_ENSEL BIT(25) 36 #define SRC_CR_T6_ENSEL BIT(27) 37 #define SRC_CR_T7_ENSEL BIT(29) 38 #define SRC_XTALCR 0x0CU 39 #define SRC_XTALCR_XTALTIMEN BIT(20) 40 #define SRC_XTALCR_SXTALDIS BIT(19) 41 #define SRC_XTALCR_MXTALSTAT BIT(2) 42 #define SRC_XTALCR_MXTALEN BIT(1) 43 #define SRC_XTALCR_MXTALOVER BIT(0) 44 #define SRC_PLLCR 0x10U 45 #define SRC_PLLCR_PLLTIMEN BIT(29) 46 #define SRC_PLLCR_PLL2EN BIT(28) 47 #define SRC_PLLCR_PLL1STAT BIT(2) 48 #define SRC_PLLCR_PLL1EN BIT(1) 49 #define SRC_PLLCR_PLL1OVER BIT(0) 50 #define SRC_PLLFR 0x14U 51 #define SRC_PCKEN0 0x24U 52 #define SRC_PCKDIS0 0x28U 53 #define SRC_PCKENSR0 0x2CU 54 #define SRC_PCKSR0 0x30U 55 #define SRC_PCKEN1 0x34U 56 #define SRC_PCKDIS1 0x38U 57 #define SRC_PCKENSR1 0x3CU 58 #define SRC_PCKSR1 0x40U 59 60 /* Lock protecting the SRC_CR register */ 61 static DEFINE_SPINLOCK(src_lock); 62 /* Base address of the SRC */ 63 static void __iomem *src_base; 64 65 static int nomadik_clk_reboot_handler(struct notifier_block *this, 66 unsigned long code, 67 void *unused) 68 { 69 u32 val; 70 71 /* The main chrystal need to be enabled for reboot to work */ 72 val = readl(src_base + SRC_XTALCR); 73 val &= ~SRC_XTALCR_MXTALOVER; 74 val |= SRC_XTALCR_MXTALEN; 75 pr_crit("force-enabling MXTALO\n"); 76 writel(val, src_base + SRC_XTALCR); 77 return NOTIFY_OK; 78 } 79 80 static struct notifier_block nomadik_clk_reboot_notifier = { 81 .notifier_call = nomadik_clk_reboot_handler, 82 }; 83 84 static const struct of_device_id nomadik_src_match[] __initconst = { 85 { .compatible = "stericsson,nomadik-src" }, 86 { /* sentinel */ } 87 }; 88 89 static void __init nomadik_src_init(void) 90 { 91 struct device_node *np; 92 u32 val; 93 94 np = of_find_matching_node(NULL, nomadik_src_match); 95 if (!np) { 96 pr_crit("no matching node for SRC, aborting clock init\n"); 97 return; 98 } 99 src_base = of_iomap(np, 0); 100 if (!src_base) { 101 pr_err("%s: must have src parent node with REGS (%s)\n", 102 __func__, np->name); 103 return; 104 } 105 106 /* Set all timers to use the 2.4 MHz TIMCLK */ 107 val = readl(src_base + SRC_CR); 108 val |= SRC_CR_T0_ENSEL; 109 val |= SRC_CR_T1_ENSEL; 110 val |= SRC_CR_T2_ENSEL; 111 val |= SRC_CR_T3_ENSEL; 112 val |= SRC_CR_T4_ENSEL; 113 val |= SRC_CR_T5_ENSEL; 114 val |= SRC_CR_T6_ENSEL; 115 val |= SRC_CR_T7_ENSEL; 116 writel(val, src_base + SRC_CR); 117 118 val = readl(src_base + SRC_XTALCR); 119 pr_info("SXTALO is %s\n", 120 (val & SRC_XTALCR_SXTALDIS) ? "disabled" : "enabled"); 121 pr_info("MXTAL is %s\n", 122 (val & SRC_XTALCR_MXTALSTAT) ? "enabled" : "disabled"); 123 if (of_property_read_bool(np, "disable-sxtalo")) { 124 /* The machine uses an external oscillator circuit */ 125 val |= SRC_XTALCR_SXTALDIS; 126 pr_info("disabling SXTALO\n"); 127 } 128 if (of_property_read_bool(np, "disable-mxtalo")) { 129 /* Disable this too: also run by external oscillator */ 130 val |= SRC_XTALCR_MXTALOVER; 131 val &= ~SRC_XTALCR_MXTALEN; 132 pr_info("disabling MXTALO\n"); 133 } 134 writel(val, src_base + SRC_XTALCR); 135 register_reboot_notifier(&nomadik_clk_reboot_notifier); 136 } 137 138 /** 139 * struct clk_pll1 - Nomadik PLL1 clock 140 * @hw: corresponding clock hardware entry 141 * @id: PLL instance: 1 or 2 142 */ 143 struct clk_pll { 144 struct clk_hw hw; 145 int id; 146 }; 147 148 /** 149 * struct clk_src - Nomadik src clock 150 * @hw: corresponding clock hardware entry 151 * @id: the clock ID 152 * @group1: true if the clock is in group1, else it is in group0 153 * @clkbit: bit 0...31 corresponding to the clock in each clock register 154 */ 155 struct clk_src { 156 struct clk_hw hw; 157 int id; 158 bool group1; 159 u32 clkbit; 160 }; 161 162 #define to_pll(_hw) container_of(_hw, struct clk_pll, hw) 163 #define to_src(_hw) container_of(_hw, struct clk_src, hw) 164 165 static int pll_clk_enable(struct clk_hw *hw) 166 { 167 struct clk_pll *pll = to_pll(hw); 168 u32 val; 169 170 spin_lock(&src_lock); 171 val = readl(src_base + SRC_PLLCR); 172 if (pll->id == 1) { 173 if (val & SRC_PLLCR_PLL1OVER) { 174 val |= SRC_PLLCR_PLL1EN; 175 writel(val, src_base + SRC_PLLCR); 176 } 177 } else if (pll->id == 2) { 178 val |= SRC_PLLCR_PLL2EN; 179 writel(val, src_base + SRC_PLLCR); 180 } 181 spin_unlock(&src_lock); 182 return 0; 183 } 184 185 static void pll_clk_disable(struct clk_hw *hw) 186 { 187 struct clk_pll *pll = to_pll(hw); 188 u32 val; 189 190 spin_lock(&src_lock); 191 val = readl(src_base + SRC_PLLCR); 192 if (pll->id == 1) { 193 if (val & SRC_PLLCR_PLL1OVER) { 194 val &= ~SRC_PLLCR_PLL1EN; 195 writel(val, src_base + SRC_PLLCR); 196 } 197 } else if (pll->id == 2) { 198 val &= ~SRC_PLLCR_PLL2EN; 199 writel(val, src_base + SRC_PLLCR); 200 } 201 spin_unlock(&src_lock); 202 } 203 204 static int pll_clk_is_enabled(struct clk_hw *hw) 205 { 206 struct clk_pll *pll = to_pll(hw); 207 u32 val; 208 209 val = readl(src_base + SRC_PLLCR); 210 if (pll->id == 1) { 211 if (val & SRC_PLLCR_PLL1OVER) 212 return !!(val & SRC_PLLCR_PLL1EN); 213 } else if (pll->id == 2) { 214 return !!(val & SRC_PLLCR_PLL2EN); 215 } 216 return 1; 217 } 218 219 static unsigned long pll_clk_recalc_rate(struct clk_hw *hw, 220 unsigned long parent_rate) 221 { 222 struct clk_pll *pll = to_pll(hw); 223 u32 val; 224 225 val = readl(src_base + SRC_PLLFR); 226 227 if (pll->id == 1) { 228 u8 mul; 229 u8 div; 230 231 mul = (val >> 8) & 0x3FU; 232 mul += 2; 233 div = val & 0x07U; 234 return (parent_rate * mul) >> div; 235 } 236 237 if (pll->id == 2) { 238 u8 mul; 239 240 mul = (val >> 24) & 0x3FU; 241 mul += 2; 242 return (parent_rate * mul); 243 } 244 245 /* Unknown PLL */ 246 return 0; 247 } 248 249 250 static const struct clk_ops pll_clk_ops = { 251 .enable = pll_clk_enable, 252 .disable = pll_clk_disable, 253 .is_enabled = pll_clk_is_enabled, 254 .recalc_rate = pll_clk_recalc_rate, 255 }; 256 257 static struct clk * __init 258 pll_clk_register(struct device *dev, const char *name, 259 const char *parent_name, u32 id) 260 { 261 struct clk *clk; 262 struct clk_pll *pll; 263 struct clk_init_data init; 264 265 if (id != 1 && id != 2) { 266 pr_err("%s: the Nomadik has only PLL 1 & 2\n", __func__); 267 return ERR_PTR(-EINVAL); 268 } 269 270 pll = kzalloc(sizeof(*pll), GFP_KERNEL); 271 if (!pll) { 272 pr_err("%s: could not allocate PLL clk\n", __func__); 273 return ERR_PTR(-ENOMEM); 274 } 275 276 init.name = name; 277 init.ops = &pll_clk_ops; 278 init.parent_names = (parent_name ? &parent_name : NULL); 279 init.num_parents = (parent_name ? 1 : 0); 280 pll->hw.init = &init; 281 pll->id = id; 282 283 pr_debug("register PLL1 clock \"%s\"\n", name); 284 285 clk = clk_register(dev, &pll->hw); 286 if (IS_ERR(clk)) 287 kfree(pll); 288 289 return clk; 290 } 291 292 /* 293 * The Nomadik SRC clocks are gated, but not in the sense that 294 * you read-modify-write a register. Instead there are separate 295 * clock enable and clock disable registers. Writing a '1' bit in 296 * the enable register for a certain clock ungates that clock without 297 * affecting the other clocks. The disable register works the opposite 298 * way. 299 */ 300 301 static int src_clk_enable(struct clk_hw *hw) 302 { 303 struct clk_src *sclk = to_src(hw); 304 u32 enreg = sclk->group1 ? SRC_PCKEN1 : SRC_PCKEN0; 305 u32 sreg = sclk->group1 ? SRC_PCKSR1 : SRC_PCKSR0; 306 307 writel(sclk->clkbit, src_base + enreg); 308 /* spin until enabled */ 309 while (!(readl(src_base + sreg) & sclk->clkbit)) 310 cpu_relax(); 311 return 0; 312 } 313 314 static void src_clk_disable(struct clk_hw *hw) 315 { 316 struct clk_src *sclk = to_src(hw); 317 u32 disreg = sclk->group1 ? SRC_PCKDIS1 : SRC_PCKDIS0; 318 u32 sreg = sclk->group1 ? SRC_PCKSR1 : SRC_PCKSR0; 319 320 writel(sclk->clkbit, src_base + disreg); 321 /* spin until disabled */ 322 while (readl(src_base + sreg) & sclk->clkbit) 323 cpu_relax(); 324 } 325 326 static int src_clk_is_enabled(struct clk_hw *hw) 327 { 328 struct clk_src *sclk = to_src(hw); 329 u32 sreg = sclk->group1 ? SRC_PCKSR1 : SRC_PCKSR0; 330 u32 val = readl(src_base + sreg); 331 332 return !!(val & sclk->clkbit); 333 } 334 335 static unsigned long 336 src_clk_recalc_rate(struct clk_hw *hw, 337 unsigned long parent_rate) 338 { 339 return parent_rate; 340 } 341 342 static const struct clk_ops src_clk_ops = { 343 .enable = src_clk_enable, 344 .disable = src_clk_disable, 345 .is_enabled = src_clk_is_enabled, 346 .recalc_rate = src_clk_recalc_rate, 347 }; 348 349 static struct clk * __init 350 src_clk_register(struct device *dev, const char *name, 351 const char *parent_name, u8 id) 352 { 353 struct clk *clk; 354 struct clk_src *sclk; 355 struct clk_init_data init; 356 357 sclk = kzalloc(sizeof(*sclk), GFP_KERNEL); 358 if (!sclk) { 359 pr_err("could not allocate SRC clock %s\n", 360 name); 361 return ERR_PTR(-ENOMEM); 362 } 363 init.name = name; 364 init.ops = &src_clk_ops; 365 /* Do not force-disable the static SDRAM controller */ 366 if (id == 2) 367 init.flags = CLK_IGNORE_UNUSED; 368 else 369 init.flags = 0; 370 init.parent_names = (parent_name ? &parent_name : NULL); 371 init.num_parents = (parent_name ? 1 : 0); 372 sclk->hw.init = &init; 373 sclk->id = id; 374 sclk->group1 = (id > 31); 375 sclk->clkbit = BIT(id & 0x1f); 376 377 pr_debug("register clock \"%s\" ID: %d group: %d bits: %08x\n", 378 name, id, sclk->group1, sclk->clkbit); 379 380 clk = clk_register(dev, &sclk->hw); 381 if (IS_ERR(clk)) 382 kfree(sclk); 383 384 return clk; 385 } 386 387 #ifdef CONFIG_DEBUG_FS 388 389 static u32 src_pcksr0_boot; 390 static u32 src_pcksr1_boot; 391 392 static const char * const src_clk_names[] = { 393 "HCLKDMA0 ", 394 "HCLKSMC ", 395 "HCLKSDRAM ", 396 "HCLKDMA1 ", 397 "HCLKCLCD ", 398 "PCLKIRDA ", 399 "PCLKSSP ", 400 "PCLKUART0 ", 401 "PCLKSDI ", 402 "PCLKI2C0 ", 403 "PCLKI2C1 ", 404 "PCLKUART1 ", 405 "PCLMSP0 ", 406 "HCLKUSB ", 407 "HCLKDIF ", 408 "HCLKSAA ", 409 "HCLKSVA ", 410 "PCLKHSI ", 411 "PCLKXTI ", 412 "PCLKUART2 ", 413 "PCLKMSP1 ", 414 "PCLKMSP2 ", 415 "PCLKOWM ", 416 "HCLKHPI ", 417 "PCLKSKE ", 418 "PCLKHSEM ", 419 "HCLK3D ", 420 "HCLKHASH ", 421 "HCLKCRYP ", 422 "PCLKMSHC ", 423 "HCLKUSBM ", 424 "HCLKRNG ", 425 "RESERVED ", 426 "RESERVED ", 427 "RESERVED ", 428 "RESERVED ", 429 "CLDCLK ", 430 "IRDACLK ", 431 "SSPICLK ", 432 "UART0CLK ", 433 "SDICLK ", 434 "I2C0CLK ", 435 "I2C1CLK ", 436 "UART1CLK ", 437 "MSPCLK0 ", 438 "USBCLK ", 439 "DIFCLK ", 440 "IPI2CCLK ", 441 "IPBMCCLK ", 442 "HSICLKRX ", 443 "HSICLKTX ", 444 "UART2CLK ", 445 "MSPCLK1 ", 446 "MSPCLK2 ", 447 "OWMCLK ", 448 "RESERVED ", 449 "SKECLK ", 450 "RESERVED ", 451 "3DCLK ", 452 "PCLKMSP3 ", 453 "MSPCLK3 ", 454 "MSHCCLK ", 455 "USBMCLK ", 456 "RNGCCLK ", 457 }; 458 459 static int nomadik_src_clk_show(struct seq_file *s, void *what) 460 { 461 int i; 462 u32 src_pcksr0 = readl(src_base + SRC_PCKSR0); 463 u32 src_pcksr1 = readl(src_base + SRC_PCKSR1); 464 u32 src_pckensr0 = readl(src_base + SRC_PCKENSR0); 465 u32 src_pckensr1 = readl(src_base + SRC_PCKENSR1); 466 467 seq_printf(s, "Clock: Boot: Now: Request: ASKED:\n"); 468 for (i = 0; i < ARRAY_SIZE(src_clk_names); i++) { 469 u32 pcksrb = (i < 0x20) ? src_pcksr0_boot : src_pcksr1_boot; 470 u32 pcksr = (i < 0x20) ? src_pcksr0 : src_pcksr1; 471 u32 pckreq = (i < 0x20) ? src_pckensr0 : src_pckensr1; 472 u32 mask = BIT(i & 0x1f); 473 474 seq_printf(s, "%s %s %s %s\n", 475 src_clk_names[i], 476 (pcksrb & mask) ? "on " : "off", 477 (pcksr & mask) ? "on " : "off", 478 (pckreq & mask) ? "on " : "off"); 479 } 480 return 0; 481 } 482 483 static int nomadik_src_clk_open(struct inode *inode, struct file *file) 484 { 485 return single_open(file, nomadik_src_clk_show, NULL); 486 } 487 488 static const struct file_operations nomadik_src_clk_debugfs_ops = { 489 .open = nomadik_src_clk_open, 490 .read = seq_read, 491 .llseek = seq_lseek, 492 .release = single_release, 493 }; 494 495 static int __init nomadik_src_clk_init_debugfs(void) 496 { 497 src_pcksr0_boot = readl(src_base + SRC_PCKSR0); 498 src_pcksr1_boot = readl(src_base + SRC_PCKSR1); 499 debugfs_create_file("nomadik-src-clk", S_IFREG | S_IRUGO, 500 NULL, NULL, &nomadik_src_clk_debugfs_ops); 501 return 0; 502 } 503 504 module_init(nomadik_src_clk_init_debugfs); 505 506 #endif 507 508 static void __init of_nomadik_pll_setup(struct device_node *np) 509 { 510 struct clk *clk = ERR_PTR(-EINVAL); 511 const char *clk_name = np->name; 512 const char *parent_name; 513 u32 pll_id; 514 515 if (!src_base) 516 nomadik_src_init(); 517 518 if (of_property_read_u32(np, "pll-id", &pll_id)) { 519 pr_err("%s: PLL \"%s\" missing pll-id property\n", 520 __func__, clk_name); 521 return; 522 } 523 parent_name = of_clk_get_parent_name(np, 0); 524 clk = pll_clk_register(NULL, clk_name, parent_name, pll_id); 525 if (!IS_ERR(clk)) 526 of_clk_add_provider(np, of_clk_src_simple_get, clk); 527 } 528 CLK_OF_DECLARE(nomadik_pll_clk, 529 "st,nomadik-pll-clock", of_nomadik_pll_setup); 530 531 static void __init of_nomadik_hclk_setup(struct device_node *np) 532 { 533 struct clk *clk = ERR_PTR(-EINVAL); 534 const char *clk_name = np->name; 535 const char *parent_name; 536 537 if (!src_base) 538 nomadik_src_init(); 539 540 parent_name = of_clk_get_parent_name(np, 0); 541 /* 542 * The HCLK divides PLL1 with 1 (passthru), 2, 3 or 4. 543 */ 544 clk = clk_register_divider(NULL, clk_name, parent_name, 545 0, src_base + SRC_CR, 546 13, 2, 547 CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ALLOW_ZERO, 548 &src_lock); 549 if (!IS_ERR(clk)) 550 of_clk_add_provider(np, of_clk_src_simple_get, clk); 551 } 552 CLK_OF_DECLARE(nomadik_hclk_clk, 553 "st,nomadik-hclk-clock", of_nomadik_hclk_setup); 554 555 static void __init of_nomadik_src_clk_setup(struct device_node *np) 556 { 557 struct clk *clk = ERR_PTR(-EINVAL); 558 const char *clk_name = np->name; 559 const char *parent_name; 560 u32 clk_id; 561 562 if (!src_base) 563 nomadik_src_init(); 564 565 if (of_property_read_u32(np, "clock-id", &clk_id)) { 566 pr_err("%s: SRC clock \"%s\" missing clock-id property\n", 567 __func__, clk_name); 568 return; 569 } 570 parent_name = of_clk_get_parent_name(np, 0); 571 clk = src_clk_register(NULL, clk_name, parent_name, clk_id); 572 if (!IS_ERR(clk)) 573 of_clk_add_provider(np, of_clk_src_simple_get, clk); 574 } 575 CLK_OF_DECLARE(nomadik_src_clk, 576 "st,nomadik-src-clock", of_nomadik_src_clk_setup); 577