1/* 2 * arch/arm/mach-ep93xx/clock.c 3 * Clock control for Cirrus EP93xx chips. 4 * 5 * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org> 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 as published by 9 * the Free Software Foundation; either version 2 of the License, or (at 10 * your option) any later version. 11 */ 12 13#define pr_fmt(fmt) "ep93xx " KBUILD_MODNAME ": " fmt 14 15#include <linux/kernel.h> 16#include <linux/clk.h> 17#include <linux/err.h> 18#include <linux/module.h> 19#include <linux/string.h> 20#include <linux/io.h> 21#include <linux/spinlock.h> 22 23#include <mach/hardware.h> 24 25#include <asm/clkdev.h> 26#include <asm/div64.h> 27 28 29struct clk { 30 struct clk *parent; 31 unsigned long rate; 32 int users; 33 int sw_locked; 34 void __iomem *enable_reg; 35 u32 enable_mask; 36 37 unsigned long (*get_rate)(struct clk *clk); 38 int (*set_rate)(struct clk *clk, unsigned long rate); 39}; 40 41 42static unsigned long get_uart_rate(struct clk *clk); 43 44static int set_keytchclk_rate(struct clk *clk, unsigned long rate); 45static int set_div_rate(struct clk *clk, unsigned long rate); 46static int set_i2s_sclk_rate(struct clk *clk, unsigned long rate); 47static int set_i2s_lrclk_rate(struct clk *clk, unsigned long rate); 48 49static struct clk clk_xtali = { 50 .rate = EP93XX_EXT_CLK_RATE, 51}; 52static struct clk clk_uart1 = { 53 .parent = &clk_xtali, 54 .sw_locked = 1, 55 .enable_reg = EP93XX_SYSCON_DEVCFG, 56 .enable_mask = EP93XX_SYSCON_DEVCFG_U1EN, 57 .get_rate = get_uart_rate, 58}; 59static struct clk clk_uart2 = { 60 .parent = &clk_xtali, 61 .sw_locked = 1, 62 .enable_reg = EP93XX_SYSCON_DEVCFG, 63 .enable_mask = EP93XX_SYSCON_DEVCFG_U2EN, 64 .get_rate = get_uart_rate, 65}; 66static struct clk clk_uart3 = { 67 .parent = &clk_xtali, 68 .sw_locked = 1, 69 .enable_reg = EP93XX_SYSCON_DEVCFG, 70 .enable_mask = EP93XX_SYSCON_DEVCFG_U3EN, 71 .get_rate = get_uart_rate, 72}; 73static struct clk clk_pll1 = { 74 .parent = &clk_xtali, 75}; 76static struct clk clk_f = { 77 .parent = &clk_pll1, 78}; 79static struct clk clk_h = { 80 .parent = &clk_pll1, 81}; 82static struct clk clk_p = { 83 .parent = &clk_pll1, 84}; 85static struct clk clk_pll2 = { 86 .parent = &clk_xtali, 87}; 88static struct clk clk_usb_host = { 89 .parent = &clk_pll2, 90 .enable_reg = EP93XX_SYSCON_PWRCNT, 91 .enable_mask = EP93XX_SYSCON_PWRCNT_USH_EN, 92}; 93static struct clk clk_keypad = { 94 .parent = &clk_xtali, 95 .sw_locked = 1, 96 .enable_reg = EP93XX_SYSCON_KEYTCHCLKDIV, 97 .enable_mask = EP93XX_SYSCON_KEYTCHCLKDIV_KEN, 98 .set_rate = set_keytchclk_rate, 99}; 100static struct clk clk_spi = { 101 .parent = &clk_xtali, 102 .rate = EP93XX_EXT_CLK_RATE, 103}; 104static struct clk clk_pwm = { 105 .parent = &clk_xtali, 106 .rate = EP93XX_EXT_CLK_RATE, 107}; 108 109static struct clk clk_video = { 110 .sw_locked = 1, 111 .enable_reg = EP93XX_SYSCON_VIDCLKDIV, 112 .enable_mask = EP93XX_SYSCON_CLKDIV_ENABLE, 113 .set_rate = set_div_rate, 114}; 115 116static struct clk clk_i2s_mclk = { 117 .sw_locked = 1, 118 .enable_reg = EP93XX_SYSCON_I2SCLKDIV, 119 .enable_mask = EP93XX_SYSCON_CLKDIV_ENABLE, 120 .set_rate = set_div_rate, 121}; 122 123static struct clk clk_i2s_sclk = { 124 .sw_locked = 1, 125 .parent = &clk_i2s_mclk, 126 .enable_reg = EP93XX_SYSCON_I2SCLKDIV, 127 .enable_mask = EP93XX_SYSCON_I2SCLKDIV_SENA, 128 .set_rate = set_i2s_sclk_rate, 129}; 130 131static struct clk clk_i2s_lrclk = { 132 .sw_locked = 1, 133 .parent = &clk_i2s_sclk, 134 .enable_reg = EP93XX_SYSCON_I2SCLKDIV, 135 .enable_mask = EP93XX_SYSCON_I2SCLKDIV_SENA, 136 .set_rate = set_i2s_lrclk_rate, 137}; 138 139/* DMA Clocks */ 140static struct clk clk_m2p0 = { 141 .parent = &clk_h, 142 .enable_reg = EP93XX_SYSCON_PWRCNT, 143 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P0, 144}; 145static struct clk clk_m2p1 = { 146 .parent = &clk_h, 147 .enable_reg = EP93XX_SYSCON_PWRCNT, 148 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P1, 149}; 150static struct clk clk_m2p2 = { 151 .parent = &clk_h, 152 .enable_reg = EP93XX_SYSCON_PWRCNT, 153 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P2, 154}; 155static struct clk clk_m2p3 = { 156 .parent = &clk_h, 157 .enable_reg = EP93XX_SYSCON_PWRCNT, 158 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P3, 159}; 160static struct clk clk_m2p4 = { 161 .parent = &clk_h, 162 .enable_reg = EP93XX_SYSCON_PWRCNT, 163 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P4, 164}; 165static struct clk clk_m2p5 = { 166 .parent = &clk_h, 167 .enable_reg = EP93XX_SYSCON_PWRCNT, 168 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P5, 169}; 170static struct clk clk_m2p6 = { 171 .parent = &clk_h, 172 .enable_reg = EP93XX_SYSCON_PWRCNT, 173 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P6, 174}; 175static struct clk clk_m2p7 = { 176 .parent = &clk_h, 177 .enable_reg = EP93XX_SYSCON_PWRCNT, 178 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P7, 179}; 180static struct clk clk_m2p8 = { 181 .parent = &clk_h, 182 .enable_reg = EP93XX_SYSCON_PWRCNT, 183 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P8, 184}; 185static struct clk clk_m2p9 = { 186 .parent = &clk_h, 187 .enable_reg = EP93XX_SYSCON_PWRCNT, 188 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P9, 189}; 190static struct clk clk_m2m0 = { 191 .parent = &clk_h, 192 .enable_reg = EP93XX_SYSCON_PWRCNT, 193 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2M0, 194}; 195static struct clk clk_m2m1 = { 196 .parent = &clk_h, 197 .enable_reg = EP93XX_SYSCON_PWRCNT, 198 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2M1, 199}; 200 201#define INIT_CK(dev,con,ck) \ 202 { .dev_id = dev, .con_id = con, .clk = ck } 203 204static struct clk_lookup clocks[] = { 205 INIT_CK(NULL, "xtali", &clk_xtali), 206 INIT_CK("apb:uart1", NULL, &clk_uart1), 207 INIT_CK("apb:uart2", NULL, &clk_uart2), 208 INIT_CK("apb:uart3", NULL, &clk_uart3), 209 INIT_CK(NULL, "pll1", &clk_pll1), 210 INIT_CK(NULL, "fclk", &clk_f), 211 INIT_CK(NULL, "hclk", &clk_h), 212 INIT_CK(NULL, "apb_pclk", &clk_p), 213 INIT_CK(NULL, "pll2", &clk_pll2), 214 INIT_CK("ep93xx-ohci", NULL, &clk_usb_host), 215 INIT_CK("ep93xx-keypad", NULL, &clk_keypad), 216 INIT_CK("ep93xx-fb", NULL, &clk_video), 217 INIT_CK("ep93xx-spi.0", NULL, &clk_spi), 218 INIT_CK("ep93xx-i2s", "mclk", &clk_i2s_mclk), 219 INIT_CK("ep93xx-i2s", "sclk", &clk_i2s_sclk), 220 INIT_CK("ep93xx-i2s", "lrclk", &clk_i2s_lrclk), 221 INIT_CK(NULL, "pwm_clk", &clk_pwm), 222 INIT_CK(NULL, "m2p0", &clk_m2p0), 223 INIT_CK(NULL, "m2p1", &clk_m2p1), 224 INIT_CK(NULL, "m2p2", &clk_m2p2), 225 INIT_CK(NULL, "m2p3", &clk_m2p3), 226 INIT_CK(NULL, "m2p4", &clk_m2p4), 227 INIT_CK(NULL, "m2p5", &clk_m2p5), 228 INIT_CK(NULL, "m2p6", &clk_m2p6), 229 INIT_CK(NULL, "m2p7", &clk_m2p7), 230 INIT_CK(NULL, "m2p8", &clk_m2p8), 231 INIT_CK(NULL, "m2p9", &clk_m2p9), 232 INIT_CK(NULL, "m2m0", &clk_m2m0), 233 INIT_CK(NULL, "m2m1", &clk_m2m1), 234}; 235 236static DEFINE_SPINLOCK(clk_lock); 237 238static void __clk_enable(struct clk *clk) 239{ 240 if (!clk->users++) { 241 if (clk->parent) 242 __clk_enable(clk->parent); 243 244 if (clk->enable_reg) { 245 u32 v; 246 247 v = __raw_readl(clk->enable_reg); 248 v |= clk->enable_mask; 249 if (clk->sw_locked) 250 ep93xx_syscon_swlocked_write(v, clk->enable_reg); 251 else 252 __raw_writel(v, clk->enable_reg); 253 } 254 } 255} 256 257int clk_enable(struct clk *clk) 258{ 259 unsigned long flags; 260 261 if (!clk) 262 return -EINVAL; 263 264 spin_lock_irqsave(&clk_lock, flags); 265 __clk_enable(clk); 266 spin_unlock_irqrestore(&clk_lock, flags); 267 268 return 0; 269} 270EXPORT_SYMBOL(clk_enable); 271 272static void __clk_disable(struct clk *clk) 273{ 274 if (!--clk->users) { 275 if (clk->enable_reg) { 276 u32 v; 277 278 v = __raw_readl(clk->enable_reg); 279 v &= ~clk->enable_mask; 280 if (clk->sw_locked) 281 ep93xx_syscon_swlocked_write(v, clk->enable_reg); 282 else 283 __raw_writel(v, clk->enable_reg); 284 } 285 286 if (clk->parent) 287 __clk_disable(clk->parent); 288 } 289} 290 291void clk_disable(struct clk *clk) 292{ 293 unsigned long flags; 294 295 if (!clk) 296 return; 297 298 spin_lock_irqsave(&clk_lock, flags); 299 __clk_disable(clk); 300 spin_unlock_irqrestore(&clk_lock, flags); 301} 302EXPORT_SYMBOL(clk_disable); 303 304static unsigned long get_uart_rate(struct clk *clk) 305{ 306 unsigned long rate = clk_get_rate(clk->parent); 307 u32 value; 308 309 value = __raw_readl(EP93XX_SYSCON_PWRCNT); 310 if (value & EP93XX_SYSCON_PWRCNT_UARTBAUD) 311 return rate; 312 else 313 return rate / 2; 314} 315 316unsigned long clk_get_rate(struct clk *clk) 317{ 318 if (clk->get_rate) 319 return clk->get_rate(clk); 320 321 return clk->rate; 322} 323EXPORT_SYMBOL(clk_get_rate); 324 325static int set_keytchclk_rate(struct clk *clk, unsigned long rate) 326{ 327 u32 val; 328 u32 div_bit; 329 330 val = __raw_readl(clk->enable_reg); 331 332 /* 333 * The Key Matrix and ADC clocks are configured using the same 334 * System Controller register. The clock used will be either 335 * 1/4 or 1/16 the external clock rate depending on the 336 * EP93XX_SYSCON_KEYTCHCLKDIV_KDIV/EP93XX_SYSCON_KEYTCHCLKDIV_ADIV 337 * bit being set or cleared. 338 */ 339 div_bit = clk->enable_mask >> 15; 340 341 if (rate == EP93XX_KEYTCHCLK_DIV4) 342 val |= div_bit; 343 else if (rate == EP93XX_KEYTCHCLK_DIV16) 344 val &= ~div_bit; 345 else 346 return -EINVAL; 347 348 ep93xx_syscon_swlocked_write(val, clk->enable_reg); 349 clk->rate = rate; 350 return 0; 351} 352 353static int calc_clk_div(struct clk *clk, unsigned long rate, 354 int *psel, int *esel, int *pdiv, int *div) 355{ 356 struct clk *mclk; 357 unsigned long max_rate, actual_rate, mclk_rate, rate_err = -1; 358 int i, found = 0, __div = 0, __pdiv = 0; 359 360 /* Don't exceed the maximum rate */ 361 max_rate = max(max(clk_pll1.rate / 4, clk_pll2.rate / 4), 362 clk_xtali.rate / 4); 363 rate = min(rate, max_rate); 364 365 /* 366 * Try the two pll's and the external clock 367 * Because the valid predividers are 2, 2.5 and 3, we multiply 368 * all the clocks by 2 to avoid floating point math. 369 * 370 * This is based on the algorithm in the ep93xx raster guide: 371 * http://be-a-maverick.com/en/pubs/appNote/AN269REV1.pdf 372 * 373 */ 374 for (i = 0; i < 3; i++) { 375 if (i == 0) 376 mclk = &clk_xtali; 377 else if (i == 1) 378 mclk = &clk_pll1; 379 else 380 mclk = &clk_pll2; 381 mclk_rate = mclk->rate * 2; 382 383 /* Try each predivider value */ 384 for (__pdiv = 4; __pdiv <= 6; __pdiv++) { 385 __div = mclk_rate / (rate * __pdiv); 386 if (__div < 2 || __div > 127) 387 continue; 388 389 actual_rate = mclk_rate / (__pdiv * __div); 390 391 if (!found || abs(actual_rate - rate) < rate_err) { 392 *pdiv = __pdiv - 3; 393 *div = __div; 394 *psel = (i == 2); 395 *esel = (i != 0); 396 clk->parent = mclk; 397 clk->rate = actual_rate; 398 rate_err = abs(actual_rate - rate); 399 found = 1; 400 } 401 } 402 } 403 404 if (!found) 405 return -EINVAL; 406 407 return 0; 408} 409 410static int set_div_rate(struct clk *clk, unsigned long rate) 411{ 412 int err, psel = 0, esel = 0, pdiv = 0, div = 0; 413 u32 val; 414 415 err = calc_clk_div(clk, rate, &psel, &esel, &pdiv, &div); 416 if (err) 417 return err; 418 419 /* Clear the esel, psel, pdiv and div bits */ 420 val = __raw_readl(clk->enable_reg); 421 val &= ~0x7fff; 422 423 /* Set the new esel, psel, pdiv and div bits for the new clock rate */ 424 val |= (esel ? EP93XX_SYSCON_CLKDIV_ESEL : 0) | 425 (psel ? EP93XX_SYSCON_CLKDIV_PSEL : 0) | 426 (pdiv << EP93XX_SYSCON_CLKDIV_PDIV_SHIFT) | div; 427 ep93xx_syscon_swlocked_write(val, clk->enable_reg); 428 return 0; 429} 430 431static int set_i2s_sclk_rate(struct clk *clk, unsigned long rate) 432{ 433 unsigned val = __raw_readl(clk->enable_reg); 434 435 if (rate == clk_i2s_mclk.rate / 2) 436 ep93xx_syscon_swlocked_write(val & ~EP93XX_I2SCLKDIV_SDIV, 437 clk->enable_reg); 438 else if (rate == clk_i2s_mclk.rate / 4) 439 ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_SDIV, 440 clk->enable_reg); 441 else 442 return -EINVAL; 443 444 clk_i2s_sclk.rate = rate; 445 return 0; 446} 447 448static int set_i2s_lrclk_rate(struct clk *clk, unsigned long rate) 449{ 450 unsigned val = __raw_readl(clk->enable_reg) & 451 ~EP93XX_I2SCLKDIV_LRDIV_MASK; 452 453 if (rate == clk_i2s_sclk.rate / 32) 454 ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV32, 455 clk->enable_reg); 456 else if (rate == clk_i2s_sclk.rate / 64) 457 ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV64, 458 clk->enable_reg); 459 else if (rate == clk_i2s_sclk.rate / 128) 460 ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV128, 461 clk->enable_reg); 462 else 463 return -EINVAL; 464 465 clk_i2s_lrclk.rate = rate; 466 return 0; 467} 468 469int clk_set_rate(struct clk *clk, unsigned long rate) 470{ 471 if (clk->set_rate) 472 return clk->set_rate(clk, rate); 473 474 return -EINVAL; 475} 476EXPORT_SYMBOL(clk_set_rate); 477 478 479static char fclk_divisors[] = { 1, 2, 4, 8, 16, 1, 1, 1 }; 480static char hclk_divisors[] = { 1, 2, 4, 5, 6, 8, 16, 32 }; 481static char pclk_divisors[] = { 1, 2, 4, 8 }; 482 483/* 484 * PLL rate = 14.7456 MHz * (X1FBD + 1) * (X2FBD + 1) / (X2IPD + 1) / 2^PS 485 */ 486static unsigned long calc_pll_rate(u32 config_word) 487{ 488 unsigned long long rate; 489 int i; 490 491 rate = clk_xtali.rate; 492 rate *= ((config_word >> 11) & 0x1f) + 1; /* X1FBD */ 493 rate *= ((config_word >> 5) & 0x3f) + 1; /* X2FBD */ 494 do_div(rate, (config_word & 0x1f) + 1); /* X2IPD */ 495 for (i = 0; i < ((config_word >> 16) & 3); i++) /* PS */ 496 rate >>= 1; 497 498 return (unsigned long)rate; 499} 500 501static void __init ep93xx_dma_clock_init(void) 502{ 503 clk_m2p0.rate = clk_h.rate; 504 clk_m2p1.rate = clk_h.rate; 505 clk_m2p2.rate = clk_h.rate; 506 clk_m2p3.rate = clk_h.rate; 507 clk_m2p4.rate = clk_h.rate; 508 clk_m2p5.rate = clk_h.rate; 509 clk_m2p6.rate = clk_h.rate; 510 clk_m2p7.rate = clk_h.rate; 511 clk_m2p8.rate = clk_h.rate; 512 clk_m2p9.rate = clk_h.rate; 513 clk_m2m0.rate = clk_h.rate; 514 clk_m2m1.rate = clk_h.rate; 515} 516 517static int __init ep93xx_clock_init(void) 518{ 519 u32 value; 520 521 /* Determine the bootloader configured pll1 rate */ 522 value = __raw_readl(EP93XX_SYSCON_CLKSET1); 523 if (!(value & EP93XX_SYSCON_CLKSET1_NBYP1)) 524 clk_pll1.rate = clk_xtali.rate; 525 else 526 clk_pll1.rate = calc_pll_rate(value); 527 528 /* Initialize the pll1 derived clocks */ 529 clk_f.rate = clk_pll1.rate / fclk_divisors[(value >> 25) & 0x7]; 530 clk_h.rate = clk_pll1.rate / hclk_divisors[(value >> 20) & 0x7]; 531 clk_p.rate = clk_h.rate / pclk_divisors[(value >> 18) & 0x3]; 532 ep93xx_dma_clock_init(); 533 534 /* Determine the bootloader configured pll2 rate */ 535 value = __raw_readl(EP93XX_SYSCON_CLKSET2); 536 if (!(value & EP93XX_SYSCON_CLKSET2_NBYP2)) 537 clk_pll2.rate = clk_xtali.rate; 538 else if (value & EP93XX_SYSCON_CLKSET2_PLL2_EN) 539 clk_pll2.rate = calc_pll_rate(value); 540 else 541 clk_pll2.rate = 0; 542 543 /* Initialize the pll2 derived clocks */ 544 clk_usb_host.rate = clk_pll2.rate / (((value >> 28) & 0xf) + 1); 545 546 /* 547 * EP93xx SSP clock rate was doubled in version E2. For more information 548 * see: 549 * http://www.cirrus.com/en/pubs/appNote/AN273REV4.pdf 550 */ 551 if (ep93xx_chip_revision() < EP93XX_CHIP_REV_E2) 552 clk_spi.rate /= 2; 553 554 pr_info("PLL1 running at %ld MHz, PLL2 at %ld MHz\n", 555 clk_pll1.rate / 1000000, clk_pll2.rate / 1000000); 556 pr_info("FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n", 557 clk_f.rate / 1000000, clk_h.rate / 1000000, 558 clk_p.rate / 1000000); 559 560 clkdev_add_table(clocks, ARRAY_SIZE(clocks)); 561 return 0; 562} 563postcore_initcall(ep93xx_clock_init); 564