1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Nomadik clock implementation 4 * Copyright (C) 2013 ST-Ericsson AB 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/slab.h> 12 #include <linux/err.h> 13 #include <linux/io.h> 14 #include <linux/clk-provider.h> 15 #include <linux/of.h> 16 #include <linux/of_address.h> 17 #include <linux/debugfs.h> 18 #include <linux/seq_file.h> 19 #include <linux/spinlock.h> 20 #include <linux/reboot.h> 21 22 /* 23 * The Nomadik clock tree is described in the STN8815A12 DB V4.2 24 * reference manual for the chip, page 94 ff. 25 * Clock IDs are in the STn8815 Reference Manual table 3, page 27. 26 */ 27 28 #define SRC_CR 0x00U 29 #define SRC_CR_T0_ENSEL BIT(15) 30 #define SRC_CR_T1_ENSEL BIT(17) 31 #define SRC_CR_T2_ENSEL BIT(19) 32 #define SRC_CR_T3_ENSEL BIT(21) 33 #define SRC_CR_T4_ENSEL BIT(23) 34 #define SRC_CR_T5_ENSEL BIT(25) 35 #define SRC_CR_T6_ENSEL BIT(27) 36 #define SRC_CR_T7_ENSEL BIT(29) 37 #define SRC_XTALCR 0x0CU 38 #define SRC_XTALCR_XTALTIMEN BIT(20) 39 #define SRC_XTALCR_SXTALDIS BIT(19) 40 #define SRC_XTALCR_MXTALSTAT BIT(2) 41 #define SRC_XTALCR_MXTALEN BIT(1) 42 #define SRC_XTALCR_MXTALOVER BIT(0) 43 #define SRC_PLLCR 0x10U 44 #define SRC_PLLCR_PLLTIMEN BIT(29) 45 #define SRC_PLLCR_PLL2EN BIT(28) 46 #define SRC_PLLCR_PLL1STAT BIT(2) 47 #define SRC_PLLCR_PLL1EN BIT(1) 48 #define SRC_PLLCR_PLL1OVER BIT(0) 49 #define SRC_PLLFR 0x14U 50 #define SRC_PCKEN0 0x24U 51 #define SRC_PCKDIS0 0x28U 52 #define SRC_PCKENSR0 0x2CU 53 #define SRC_PCKSR0 0x30U 54 #define SRC_PCKEN1 0x34U 55 #define SRC_PCKDIS1 0x38U 56 #define SRC_PCKENSR1 0x3CU 57 #define SRC_PCKSR1 0x40U 58 59 /* Lock protecting the SRC_CR register */ 60 static DEFINE_SPINLOCK(src_lock); 61 /* Base address of the SRC */ 62 static void __iomem *src_base; 63 nomadik_clk_reboot_handler(struct notifier_block * this,unsigned long code,void * unused)64 static int nomadik_clk_reboot_handler(struct notifier_block *this, 65 unsigned long code, 66 void *unused) 67 { 68 u32 val; 69 70 /* The main chrystal need to be enabled for reboot to work */ 71 val = readl(src_base + SRC_XTALCR); 72 val &= ~SRC_XTALCR_MXTALOVER; 73 val |= SRC_XTALCR_MXTALEN; 74 pr_crit("force-enabling MXTALO\n"); 75 writel(val, src_base + SRC_XTALCR); 76 return NOTIFY_OK; 77 } 78 79 static struct notifier_block nomadik_clk_reboot_notifier = { 80 .notifier_call = nomadik_clk_reboot_handler, 81 }; 82 83 static const struct of_device_id nomadik_src_match[] __initconst = { 84 { .compatible = "stericsson,nomadik-src" }, 85 { /* sentinel */ } 86 }; 87 nomadik_src_init(void)88 static void __init nomadik_src_init(void) 89 { 90 struct device_node *np; 91 u32 val; 92 93 np = of_find_matching_node(NULL, nomadik_src_match); 94 if (!np) { 95 pr_crit("no matching node for SRC, aborting clock init\n"); 96 return; 97 } 98 src_base = of_iomap(np, 0); 99 if (!src_base) { 100 pr_err("%s: must have src parent node with REGS (%pOFn)\n", 101 __func__, np); 102 goto out_put; 103 } 104 105 /* Set all timers to use the 2.4 MHz TIMCLK */ 106 val = readl(src_base + SRC_CR); 107 val |= SRC_CR_T0_ENSEL; 108 val |= SRC_CR_T1_ENSEL; 109 val |= SRC_CR_T2_ENSEL; 110 val |= SRC_CR_T3_ENSEL; 111 val |= SRC_CR_T4_ENSEL; 112 val |= SRC_CR_T5_ENSEL; 113 val |= SRC_CR_T6_ENSEL; 114 val |= SRC_CR_T7_ENSEL; 115 writel(val, src_base + SRC_CR); 116 117 val = readl(src_base + SRC_XTALCR); 118 pr_info("SXTALO is %s\n", 119 (val & SRC_XTALCR_SXTALDIS) ? "disabled" : "enabled"); 120 pr_info("MXTAL is %s\n", 121 (val & SRC_XTALCR_MXTALSTAT) ? "enabled" : "disabled"); 122 if (of_property_read_bool(np, "disable-sxtalo")) { 123 /* The machine uses an external oscillator circuit */ 124 val |= SRC_XTALCR_SXTALDIS; 125 pr_info("disabling SXTALO\n"); 126 } 127 if (of_property_read_bool(np, "disable-mxtalo")) { 128 /* Disable this too: also run by external oscillator */ 129 val |= SRC_XTALCR_MXTALOVER; 130 val &= ~SRC_XTALCR_MXTALEN; 131 pr_info("disabling MXTALO\n"); 132 } 133 writel(val, src_base + SRC_XTALCR); 134 register_reboot_notifier(&nomadik_clk_reboot_notifier); 135 136 out_put: 137 of_node_put(np); 138 } 139 140 /** 141 * struct clk_pll - Nomadik PLL clock 142 * @hw: corresponding clock hardware entry 143 * @id: PLL instance: 1 or 2 144 */ 145 struct clk_pll { 146 struct clk_hw hw; 147 int id; 148 }; 149 150 /** 151 * struct clk_src - Nomadik src clock 152 * @hw: corresponding clock hardware entry 153 * @id: the clock ID 154 * @group1: true if the clock is in group1, else it is in group0 155 * @clkbit: bit 0...31 corresponding to the clock in each clock register 156 */ 157 struct clk_src { 158 struct clk_hw hw; 159 int id; 160 bool group1; 161 u32 clkbit; 162 }; 163 164 #define to_pll(_hw) container_of(_hw, struct clk_pll, hw) 165 #define to_src(_hw) container_of(_hw, struct clk_src, hw) 166 pll_clk_enable(struct clk_hw * hw)167 static int pll_clk_enable(struct clk_hw *hw) 168 { 169 struct clk_pll *pll = to_pll(hw); 170 u32 val; 171 172 spin_lock(&src_lock); 173 val = readl(src_base + SRC_PLLCR); 174 if (pll->id == 1) { 175 if (val & SRC_PLLCR_PLL1OVER) { 176 val |= SRC_PLLCR_PLL1EN; 177 writel(val, src_base + SRC_PLLCR); 178 } 179 } else if (pll->id == 2) { 180 val |= SRC_PLLCR_PLL2EN; 181 writel(val, src_base + SRC_PLLCR); 182 } 183 spin_unlock(&src_lock); 184 return 0; 185 } 186 pll_clk_disable(struct clk_hw * hw)187 static void pll_clk_disable(struct clk_hw *hw) 188 { 189 struct clk_pll *pll = to_pll(hw); 190 u32 val; 191 192 spin_lock(&src_lock); 193 val = readl(src_base + SRC_PLLCR); 194 if (pll->id == 1) { 195 if (val & SRC_PLLCR_PLL1OVER) { 196 val &= ~SRC_PLLCR_PLL1EN; 197 writel(val, src_base + SRC_PLLCR); 198 } 199 } else if (pll->id == 2) { 200 val &= ~SRC_PLLCR_PLL2EN; 201 writel(val, src_base + SRC_PLLCR); 202 } 203 spin_unlock(&src_lock); 204 } 205 pll_clk_is_enabled(struct clk_hw * hw)206 static int pll_clk_is_enabled(struct clk_hw *hw) 207 { 208 struct clk_pll *pll = to_pll(hw); 209 u32 val; 210 211 val = readl(src_base + SRC_PLLCR); 212 if (pll->id == 1) { 213 if (val & SRC_PLLCR_PLL1OVER) 214 return !!(val & SRC_PLLCR_PLL1EN); 215 } else if (pll->id == 2) { 216 return !!(val & SRC_PLLCR_PLL2EN); 217 } 218 return 1; 219 } 220 pll_clk_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)221 static unsigned long pll_clk_recalc_rate(struct clk_hw *hw, 222 unsigned long parent_rate) 223 { 224 struct clk_pll *pll = to_pll(hw); 225 u32 val; 226 227 val = readl(src_base + SRC_PLLFR); 228 229 if (pll->id == 1) { 230 u8 mul; 231 u8 div; 232 233 mul = (val >> 8) & 0x3FU; 234 mul += 2; 235 div = val & 0x07U; 236 return (parent_rate * mul) >> div; 237 } 238 239 if (pll->id == 2) { 240 u8 mul; 241 242 mul = (val >> 24) & 0x3FU; 243 mul += 2; 244 return (parent_rate * mul); 245 } 246 247 /* Unknown PLL */ 248 return 0; 249 } 250 251 252 static const struct clk_ops pll_clk_ops = { 253 .enable = pll_clk_enable, 254 .disable = pll_clk_disable, 255 .is_enabled = pll_clk_is_enabled, 256 .recalc_rate = pll_clk_recalc_rate, 257 }; 258 259 static struct clk_hw * __init pll_clk_register(struct device * dev,const char * name,const char * parent_name,u32 id)260 pll_clk_register(struct device *dev, const char *name, 261 const char *parent_name, u32 id) 262 { 263 int ret; 264 struct clk_pll *pll; 265 struct clk_init_data init; 266 267 if (id != 1 && id != 2) { 268 pr_err("%s: the Nomadik has only PLL 1 & 2\n", __func__); 269 return ERR_PTR(-EINVAL); 270 } 271 272 pll = kzalloc(sizeof(*pll), GFP_KERNEL); 273 if (!pll) 274 return ERR_PTR(-ENOMEM); 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 ret = clk_hw_register(dev, &pll->hw); 286 if (ret) { 287 kfree(pll); 288 return ERR_PTR(ret); 289 } 290 291 return &pll->hw; 292 } 293 294 /* 295 * The Nomadik SRC clocks are gated, but not in the sense that 296 * you read-modify-write a register. Instead there are separate 297 * clock enable and clock disable registers. Writing a '1' bit in 298 * the enable register for a certain clock ungates that clock without 299 * affecting the other clocks. The disable register works the opposite 300 * way. 301 */ 302 src_clk_enable(struct clk_hw * hw)303 static int src_clk_enable(struct clk_hw *hw) 304 { 305 struct clk_src *sclk = to_src(hw); 306 u32 enreg = sclk->group1 ? SRC_PCKEN1 : SRC_PCKEN0; 307 u32 sreg = sclk->group1 ? SRC_PCKSR1 : SRC_PCKSR0; 308 309 writel(sclk->clkbit, src_base + enreg); 310 /* spin until enabled */ 311 while (!(readl(src_base + sreg) & sclk->clkbit)) 312 cpu_relax(); 313 return 0; 314 } 315 src_clk_disable(struct clk_hw * hw)316 static void src_clk_disable(struct clk_hw *hw) 317 { 318 struct clk_src *sclk = to_src(hw); 319 u32 disreg = sclk->group1 ? SRC_PCKDIS1 : SRC_PCKDIS0; 320 u32 sreg = sclk->group1 ? SRC_PCKSR1 : SRC_PCKSR0; 321 322 writel(sclk->clkbit, src_base + disreg); 323 /* spin until disabled */ 324 while (readl(src_base + sreg) & sclk->clkbit) 325 cpu_relax(); 326 } 327 src_clk_is_enabled(struct clk_hw * hw)328 static int src_clk_is_enabled(struct clk_hw *hw) 329 { 330 struct clk_src *sclk = to_src(hw); 331 u32 sreg = sclk->group1 ? SRC_PCKSR1 : SRC_PCKSR0; 332 u32 val = readl(src_base + sreg); 333 334 return !!(val & sclk->clkbit); 335 } 336 337 static unsigned long src_clk_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)338 src_clk_recalc_rate(struct clk_hw *hw, 339 unsigned long parent_rate) 340 { 341 return parent_rate; 342 } 343 344 static const struct clk_ops src_clk_ops = { 345 .enable = src_clk_enable, 346 .disable = src_clk_disable, 347 .is_enabled = src_clk_is_enabled, 348 .recalc_rate = src_clk_recalc_rate, 349 }; 350 351 static struct clk_hw * __init src_clk_register(struct device * dev,const char * name,const char * parent_name,u8 id)352 src_clk_register(struct device *dev, const char *name, 353 const char *parent_name, u8 id) 354 { 355 int ret; 356 struct clk_src *sclk; 357 struct clk_init_data init; 358 359 sclk = kzalloc(sizeof(*sclk), GFP_KERNEL); 360 if (!sclk) 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 ret = clk_hw_register(dev, &sclk->hw); 381 if (ret) { 382 kfree(sclk); 383 return ERR_PTR(ret); 384 } 385 386 return &sclk->hw; 387 } 388 389 #ifdef CONFIG_DEBUG_FS 390 391 static u32 src_pcksr0_boot; 392 static u32 src_pcksr1_boot; 393 394 static const char * const src_clk_names[] = { 395 "HCLKDMA0 ", 396 "HCLKSMC ", 397 "HCLKSDRAM ", 398 "HCLKDMA1 ", 399 "HCLKCLCD ", 400 "PCLKIRDA ", 401 "PCLKSSP ", 402 "PCLKUART0 ", 403 "PCLKSDI ", 404 "PCLKI2C0 ", 405 "PCLKI2C1 ", 406 "PCLKUART1 ", 407 "PCLMSP0 ", 408 "HCLKUSB ", 409 "HCLKDIF ", 410 "HCLKSAA ", 411 "HCLKSVA ", 412 "PCLKHSI ", 413 "PCLKXTI ", 414 "PCLKUART2 ", 415 "PCLKMSP1 ", 416 "PCLKMSP2 ", 417 "PCLKOWM ", 418 "HCLKHPI ", 419 "PCLKSKE ", 420 "PCLKHSEM ", 421 "HCLK3D ", 422 "HCLKHASH ", 423 "HCLKCRYP ", 424 "PCLKMSHC ", 425 "HCLKUSBM ", 426 "HCLKRNG ", 427 "RESERVED ", 428 "RESERVED ", 429 "RESERVED ", 430 "RESERVED ", 431 "CLDCLK ", 432 "IRDACLK ", 433 "SSPICLK ", 434 "UART0CLK ", 435 "SDICLK ", 436 "I2C0CLK ", 437 "I2C1CLK ", 438 "UART1CLK ", 439 "MSPCLK0 ", 440 "USBCLK ", 441 "DIFCLK ", 442 "IPI2CCLK ", 443 "IPBMCCLK ", 444 "HSICLKRX ", 445 "HSICLKTX ", 446 "UART2CLK ", 447 "MSPCLK1 ", 448 "MSPCLK2 ", 449 "OWMCLK ", 450 "RESERVED ", 451 "SKECLK ", 452 "RESERVED ", 453 "3DCLK ", 454 "PCLKMSP3 ", 455 "MSPCLK3 ", 456 "MSHCCLK ", 457 "USBMCLK ", 458 "RNGCCLK ", 459 }; 460 nomadik_src_clk_debugfs_show(struct seq_file * s,void * what)461 static int nomadik_src_clk_debugfs_show(struct seq_file *s, void *what) 462 { 463 int i; 464 u32 src_pcksr0 = readl(src_base + SRC_PCKSR0); 465 u32 src_pcksr1 = readl(src_base + SRC_PCKSR1); 466 u32 src_pckensr0 = readl(src_base + SRC_PCKENSR0); 467 u32 src_pckensr1 = readl(src_base + SRC_PCKENSR1); 468 469 seq_puts(s, "Clock: Boot: Now: Request: ASKED:\n"); 470 for (i = 0; i < ARRAY_SIZE(src_clk_names); i++) { 471 u32 pcksrb = (i < 0x20) ? src_pcksr0_boot : src_pcksr1_boot; 472 u32 pcksr = (i < 0x20) ? src_pcksr0 : src_pcksr1; 473 u32 pckreq = (i < 0x20) ? src_pckensr0 : src_pckensr1; 474 u32 mask = BIT(i & 0x1f); 475 476 seq_printf(s, "%s %s %s %s\n", 477 src_clk_names[i], 478 (pcksrb & mask) ? "on " : "off", 479 (pcksr & mask) ? "on " : "off", 480 (pckreq & mask) ? "on " : "off"); 481 } 482 return 0; 483 } 484 485 DEFINE_SHOW_ATTRIBUTE(nomadik_src_clk_debugfs); 486 nomadik_src_clk_init_debugfs(void)487 static int __init nomadik_src_clk_init_debugfs(void) 488 { 489 /* Vital for multiplatform */ 490 if (!src_base) 491 return -ENODEV; 492 src_pcksr0_boot = readl(src_base + SRC_PCKSR0); 493 src_pcksr1_boot = readl(src_base + SRC_PCKSR1); 494 debugfs_create_file("nomadik-src-clk", S_IFREG | S_IRUGO, 495 NULL, NULL, &nomadik_src_clk_debugfs_fops); 496 return 0; 497 } 498 device_initcall(nomadik_src_clk_init_debugfs); 499 500 #endif 501 of_nomadik_pll_setup(struct device_node * np)502 static void __init of_nomadik_pll_setup(struct device_node *np) 503 { 504 struct clk_hw *hw; 505 const char *clk_name = np->name; 506 const char *parent_name; 507 u32 pll_id; 508 509 if (!src_base) 510 nomadik_src_init(); 511 512 if (of_property_read_u32(np, "pll-id", &pll_id)) { 513 pr_err("%s: PLL \"%s\" missing pll-id property\n", 514 __func__, clk_name); 515 return; 516 } 517 parent_name = of_clk_get_parent_name(np, 0); 518 hw = pll_clk_register(NULL, clk_name, parent_name, pll_id); 519 if (!IS_ERR(hw)) 520 of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw); 521 } 522 CLK_OF_DECLARE(nomadik_pll_clk, 523 "st,nomadik-pll-clock", of_nomadik_pll_setup); 524 of_nomadik_hclk_setup(struct device_node * np)525 static void __init of_nomadik_hclk_setup(struct device_node *np) 526 { 527 struct clk_hw *hw; 528 const char *clk_name = np->name; 529 const char *parent_name; 530 531 if (!src_base) 532 nomadik_src_init(); 533 534 parent_name = of_clk_get_parent_name(np, 0); 535 /* 536 * The HCLK divides PLL1 with 1 (passthru), 2, 3 or 4. 537 */ 538 hw = clk_hw_register_divider(NULL, clk_name, parent_name, 539 0, src_base + SRC_CR, 540 13, 2, 541 CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ALLOW_ZERO, 542 &src_lock); 543 if (!IS_ERR(hw)) 544 of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw); 545 } 546 CLK_OF_DECLARE(nomadik_hclk_clk, 547 "st,nomadik-hclk-clock", of_nomadik_hclk_setup); 548 of_nomadik_src_clk_setup(struct device_node * np)549 static void __init of_nomadik_src_clk_setup(struct device_node *np) 550 { 551 struct clk_hw *hw; 552 const char *clk_name = np->name; 553 const char *parent_name; 554 u32 clk_id; 555 556 if (!src_base) 557 nomadik_src_init(); 558 559 if (of_property_read_u32(np, "clock-id", &clk_id)) { 560 pr_err("%s: SRC clock \"%s\" missing clock-id property\n", 561 __func__, clk_name); 562 return; 563 } 564 parent_name = of_clk_get_parent_name(np, 0); 565 hw = src_clk_register(NULL, clk_name, parent_name, clk_id); 566 if (!IS_ERR(hw)) 567 of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw); 568 } 569 CLK_OF_DECLARE(nomadik_src_clk, 570 "st,nomadik-src-clock", of_nomadik_src_clk_setup); 571