1/* linux/drivers/mmc/host/sdhci-s3c.c 2 * 3 * Copyright 2008 Openmoko Inc. 4 * Copyright 2008 Simtec Electronics 5 * Ben Dooks <ben@simtec.co.uk> 6 * http://armlinux.simtec.co.uk/ 7 * 8 * SDHCI (HSMMC) support for Samsung SoC 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 */ 14 15#include <linux/delay.h> 16#include <linux/dma-mapping.h> 17#include <linux/platform_device.h> 18#include <linux/slab.h> 19#include <linux/clk.h> 20#include <linux/io.h> 21#include <linux/gpio.h> 22 23#include <linux/mmc/host.h> 24 25#include <plat/sdhci.h> 26#include <plat/regs-sdhci.h> 27 28#include "sdhci.h" 29 30#define MAX_BUS_CLK (4) 31 32/** 33 * struct sdhci_s3c - S3C SDHCI instance 34 * @host: The SDHCI host created 35 * @pdev: The platform device we where created from. 36 * @ioarea: The resource created when we claimed the IO area. 37 * @pdata: The platform data for this controller. 38 * @cur_clk: The index of the current bus clock. 39 * @clk_io: The clock for the internal bus interface. 40 * @clk_bus: The clocks that are available for the SD/MMC bus clock. 41 */ 42struct sdhci_s3c { 43 struct sdhci_host *host; 44 struct platform_device *pdev; 45 struct resource *ioarea; 46 struct s3c_sdhci_platdata *pdata; 47 unsigned int cur_clk; 48 int ext_cd_irq; 49 int ext_cd_gpio; 50 51 struct clk *clk_io; 52 struct clk *clk_bus[MAX_BUS_CLK]; 53}; 54 55static inline struct sdhci_s3c *to_s3c(struct sdhci_host *host) 56{ 57 return sdhci_priv(host); 58} 59 60/** 61 * get_curclk - convert ctrl2 register to clock source number 62 * @ctrl2: Control2 register value. 63 */ 64static u32 get_curclk(u32 ctrl2) 65{ 66 ctrl2 &= S3C_SDHCI_CTRL2_SELBASECLK_MASK; 67 ctrl2 >>= S3C_SDHCI_CTRL2_SELBASECLK_SHIFT; 68 69 return ctrl2; 70} 71 72static void sdhci_s3c_check_sclk(struct sdhci_host *host) 73{ 74 struct sdhci_s3c *ourhost = to_s3c(host); 75 u32 tmp = readl(host->ioaddr + S3C_SDHCI_CONTROL2); 76 77 if (get_curclk(tmp) != ourhost->cur_clk) { 78 dev_dbg(&ourhost->pdev->dev, "restored ctrl2 clock setting\n"); 79 80 tmp &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK; 81 tmp |= ourhost->cur_clk << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT; 82 writel(tmp, host->ioaddr + 0x80); 83 } 84} 85 86/** 87 * sdhci_s3c_get_max_clk - callback to get maximum clock frequency. 88 * @host: The SDHCI host instance. 89 * 90 * Callback to return the maximum clock rate acheivable by the controller. 91*/ 92static unsigned int sdhci_s3c_get_max_clk(struct sdhci_host *host) 93{ 94 struct sdhci_s3c *ourhost = to_s3c(host); 95 struct clk *busclk; 96 unsigned int rate, max; 97 int clk; 98 99 /* note, a reset will reset the clock source */ 100 101 sdhci_s3c_check_sclk(host); 102 103 for (max = 0, clk = 0; clk < MAX_BUS_CLK; clk++) { 104 busclk = ourhost->clk_bus[clk]; 105 if (!busclk) 106 continue; 107 108 rate = clk_get_rate(busclk); 109 if (rate > max) 110 max = rate; 111 } 112 113 return max; 114} 115 116/** 117 * sdhci_s3c_consider_clock - consider one the bus clocks for current setting 118 * @ourhost: Our SDHCI instance. 119 * @src: The source clock index. 120 * @wanted: The clock frequency wanted. 121 */ 122static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost, 123 unsigned int src, 124 unsigned int wanted) 125{ 126 unsigned long rate; 127 struct clk *clksrc = ourhost->clk_bus[src]; 128 int div; 129 130 if (!clksrc) 131 return UINT_MAX; 132 133 rate = clk_get_rate(clksrc); 134 135 for (div = 1; div < 256; div *= 2) { 136 if ((rate / div) <= wanted) 137 break; 138 } 139 140 dev_dbg(&ourhost->pdev->dev, "clk %d: rate %ld, want %d, got %ld\n", 141 src, rate, wanted, rate / div); 142 143 return (wanted - (rate / div)); 144} 145 146/** 147 * sdhci_s3c_set_clock - callback on clock change 148 * @host: The SDHCI host being changed 149 * @clock: The clock rate being requested. 150 * 151 * When the card's clock is going to be changed, look at the new frequency 152 * and find the best clock source to go with it. 153*/ 154static void sdhci_s3c_set_clock(struct sdhci_host *host, unsigned int clock) 155{ 156 struct sdhci_s3c *ourhost = to_s3c(host); 157 unsigned int best = UINT_MAX; 158 unsigned int delta; 159 int best_src = 0; 160 int src; 161 u32 ctrl; 162 163 /* don't bother if the clock is going off. */ 164 if (clock == 0) 165 return; 166 167 for (src = 0; src < MAX_BUS_CLK; src++) { 168 delta = sdhci_s3c_consider_clock(ourhost, src, clock); 169 if (delta < best) { 170 best = delta; 171 best_src = src; 172 } 173 } 174 175 dev_dbg(&ourhost->pdev->dev, 176 "selected source %d, clock %d, delta %d\n", 177 best_src, clock, best); 178 179 /* select the new clock source */ 180 181 if (ourhost->cur_clk != best_src) { 182 struct clk *clk = ourhost->clk_bus[best_src]; 183 184 /* turn clock off to card before changing clock source */ 185 writew(0, host->ioaddr + SDHCI_CLOCK_CONTROL); 186 187 ourhost->cur_clk = best_src; 188 host->max_clk = clk_get_rate(clk); 189 190 ctrl = readl(host->ioaddr + S3C_SDHCI_CONTROL2); 191 ctrl &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK; 192 ctrl |= best_src << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT; 193 writel(ctrl, host->ioaddr + S3C_SDHCI_CONTROL2); 194 } 195 196 /* reconfigure the hardware for new clock rate */ 197 198 { 199 struct mmc_ios ios; 200 201 ios.clock = clock; 202 203 if (ourhost->pdata->cfg_card) 204 (ourhost->pdata->cfg_card)(ourhost->pdev, host->ioaddr, 205 &ios, NULL); 206 } 207} 208 209/** 210 * sdhci_s3c_get_min_clock - callback to get minimal supported clock value 211 * @host: The SDHCI host being queried 212 * 213 * To init mmc host properly a minimal clock value is needed. For high system 214 * bus clock's values the standard formula gives values out of allowed range. 215 * The clock still can be set to lower values, if clock source other then 216 * system bus is selected. 217*/ 218static unsigned int sdhci_s3c_get_min_clock(struct sdhci_host *host) 219{ 220 struct sdhci_s3c *ourhost = to_s3c(host); 221 unsigned int delta, min = UINT_MAX; 222 int src; 223 224 for (src = 0; src < MAX_BUS_CLK; src++) { 225 delta = sdhci_s3c_consider_clock(ourhost, src, 0); 226 if (delta == UINT_MAX) 227 continue; 228 /* delta is a negative value in this case */ 229 if (-delta < min) 230 min = -delta; 231 } 232 return min; 233} 234 235static struct sdhci_ops sdhci_s3c_ops = { 236 .get_max_clock = sdhci_s3c_get_max_clk, 237 .set_clock = sdhci_s3c_set_clock, 238 .get_min_clock = sdhci_s3c_get_min_clock, 239}; 240 241static void sdhci_s3c_notify_change(struct platform_device *dev, int state) 242{ 243 struct sdhci_host *host = platform_get_drvdata(dev); 244 unsigned long flags; 245 246 if (host) { 247 spin_lock_irqsave(&host->lock, flags); 248 if (state) { 249 dev_dbg(&dev->dev, "card inserted.\n"); 250 host->flags &= ~SDHCI_DEVICE_DEAD; 251 host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION; 252 } else { 253 dev_dbg(&dev->dev, "card removed.\n"); 254 host->flags |= SDHCI_DEVICE_DEAD; 255 host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION; 256 } 257 tasklet_schedule(&host->card_tasklet); 258 spin_unlock_irqrestore(&host->lock, flags); 259 } 260} 261 262static irqreturn_t sdhci_s3c_gpio_card_detect_thread(int irq, void *dev_id) 263{ 264 struct sdhci_s3c *sc = dev_id; 265 int status = gpio_get_value(sc->ext_cd_gpio); 266 if (sc->pdata->ext_cd_gpio_invert) 267 status = !status; 268 sdhci_s3c_notify_change(sc->pdev, status); 269 return IRQ_HANDLED; 270} 271 272static void sdhci_s3c_setup_card_detect_gpio(struct sdhci_s3c *sc) 273{ 274 struct s3c_sdhci_platdata *pdata = sc->pdata; 275 struct device *dev = &sc->pdev->dev; 276 277 if (gpio_request(pdata->ext_cd_gpio, "SDHCI EXT CD") == 0) { 278 sc->ext_cd_gpio = pdata->ext_cd_gpio; 279 sc->ext_cd_irq = gpio_to_irq(pdata->ext_cd_gpio); 280 if (sc->ext_cd_irq && 281 request_threaded_irq(sc->ext_cd_irq, NULL, 282 sdhci_s3c_gpio_card_detect_thread, 283 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, 284 dev_name(dev), sc) == 0) { 285 int status = gpio_get_value(sc->ext_cd_gpio); 286 if (pdata->ext_cd_gpio_invert) 287 status = !status; 288 sdhci_s3c_notify_change(sc->pdev, status); 289 } else { 290 dev_warn(dev, "cannot request irq for card detect\n"); 291 sc->ext_cd_irq = 0; 292 } 293 } else { 294 dev_err(dev, "cannot request gpio for card detect\n"); 295 } 296} 297 298static int __devinit sdhci_s3c_probe(struct platform_device *pdev) 299{ 300 struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data; 301 struct device *dev = &pdev->dev; 302 struct sdhci_host *host; 303 struct sdhci_s3c *sc; 304 struct resource *res; 305 int ret, irq, ptr, clks; 306 307 if (!pdata) { 308 dev_err(dev, "no device data specified\n"); 309 return -ENOENT; 310 } 311 312 irq = platform_get_irq(pdev, 0); 313 if (irq < 0) { 314 dev_err(dev, "no irq specified\n"); 315 return irq; 316 } 317 318 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 319 if (!res) { 320 dev_err(dev, "no memory specified\n"); 321 return -ENOENT; 322 } 323 324 host = sdhci_alloc_host(dev, sizeof(struct sdhci_s3c)); 325 if (IS_ERR(host)) { 326 dev_err(dev, "sdhci_alloc_host() failed\n"); 327 return PTR_ERR(host); 328 } 329 330 sc = sdhci_priv(host); 331 332 sc->host = host; 333 sc->pdev = pdev; 334 sc->pdata = pdata; 335 sc->ext_cd_gpio = -1; /* invalid gpio number */ 336 337 platform_set_drvdata(pdev, host); 338 339 sc->clk_io = clk_get(dev, "hsmmc"); 340 if (IS_ERR(sc->clk_io)) { 341 dev_err(dev, "failed to get io clock\n"); 342 ret = PTR_ERR(sc->clk_io); 343 goto err_io_clk; 344 } 345 346 /* enable the local io clock and keep it running for the moment. */ 347 clk_enable(sc->clk_io); 348 349 for (clks = 0, ptr = 0; ptr < MAX_BUS_CLK; ptr++) { 350 struct clk *clk; 351 char *name = pdata->clocks[ptr]; 352 353 if (name == NULL) 354 continue; 355 356 clk = clk_get(dev, name); 357 if (IS_ERR(clk)) { 358 dev_err(dev, "failed to get clock %s\n", name); 359 continue; 360 } 361 362 clks++; 363 sc->clk_bus[ptr] = clk; 364 clk_enable(clk); 365 366 dev_info(dev, "clock source %d: %s (%ld Hz)\n", 367 ptr, name, clk_get_rate(clk)); 368 } 369 370 if (clks == 0) { 371 dev_err(dev, "failed to find any bus clocks\n"); 372 ret = -ENOENT; 373 goto err_no_busclks; 374 } 375 376 sc->ioarea = request_mem_region(res->start, resource_size(res), 377 mmc_hostname(host->mmc)); 378 if (!sc->ioarea) { 379 dev_err(dev, "failed to reserve register area\n"); 380 ret = -ENXIO; 381 goto err_req_regs; 382 } 383 384 host->ioaddr = ioremap_nocache(res->start, resource_size(res)); 385 if (!host->ioaddr) { 386 dev_err(dev, "failed to map registers\n"); 387 ret = -ENXIO; 388 goto err_req_regs; 389 } 390 391 /* Ensure we have minimal gpio selected CMD/CLK/Detect */ 392 if (pdata->cfg_gpio) 393 pdata->cfg_gpio(pdev, pdata->max_width); 394 395 host->hw_name = "samsung-hsmmc"; 396 host->ops = &sdhci_s3c_ops; 397 host->quirks = 0; 398 host->irq = irq; 399 400 /* Setup quirks for the controller */ 401 host->quirks |= SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC; 402 host->quirks |= SDHCI_QUIRK_NO_HISPD_BIT; 403 404#ifndef CONFIG_MMC_SDHCI_S3C_DMA 405 406 /* we currently see overruns on errors, so disable the SDMA 407 * support as well. */ 408 host->quirks |= SDHCI_QUIRK_BROKEN_DMA; 409 410#endif /* CONFIG_MMC_SDHCI_S3C_DMA */ 411 412 /* It seems we do not get an DATA transfer complete on non-busy 413 * transfers, not sure if this is a problem with this specific 414 * SDHCI block, or a missing configuration that needs to be set. */ 415 host->quirks |= SDHCI_QUIRK_NO_BUSY_IRQ; 416 417 if (pdata->cd_type == S3C_SDHCI_CD_NONE || 418 pdata->cd_type == S3C_SDHCI_CD_PERMANENT) 419 host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION; 420 421 if (pdata->cd_type == S3C_SDHCI_CD_PERMANENT) 422 host->mmc->caps = MMC_CAP_NONREMOVABLE; 423 424 host->quirks |= (SDHCI_QUIRK_32BIT_DMA_ADDR | 425 SDHCI_QUIRK_32BIT_DMA_SIZE); 426 427 /* HSMMC on Samsung SoCs uses SDCLK as timeout clock */ 428 host->quirks |= SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK; 429 430 ret = sdhci_add_host(host); 431 if (ret) { 432 dev_err(dev, "sdhci_add_host() failed\n"); 433 goto err_add_host; 434 } 435 436 /* The following two methods of card detection might call 437 sdhci_s3c_notify_change() immediately, so they can be called 438 only after sdhci_add_host(). Setup errors are ignored. */ 439 if (pdata->cd_type == S3C_SDHCI_CD_EXTERNAL && pdata->ext_cd_init) 440 pdata->ext_cd_init(&sdhci_s3c_notify_change); 441 if (pdata->cd_type == S3C_SDHCI_CD_GPIO && 442 gpio_is_valid(pdata->ext_cd_gpio)) 443 sdhci_s3c_setup_card_detect_gpio(sc); 444 445 return 0; 446 447 err_add_host: 448 release_resource(sc->ioarea); 449 kfree(sc->ioarea); 450 451 err_req_regs: 452 for (ptr = 0; ptr < MAX_BUS_CLK; ptr++) { 453 clk_disable(sc->clk_bus[ptr]); 454 clk_put(sc->clk_bus[ptr]); 455 } 456 457 err_no_busclks: 458 clk_disable(sc->clk_io); 459 clk_put(sc->clk_io); 460 461 err_io_clk: 462 sdhci_free_host(host); 463 464 return ret; 465} 466 467static int __devexit sdhci_s3c_remove(struct platform_device *pdev) 468{ 469 struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data; 470 struct sdhci_host *host = platform_get_drvdata(pdev); 471 struct sdhci_s3c *sc = sdhci_priv(host); 472 int ptr; 473 474 if (pdata->cd_type == S3C_SDHCI_CD_EXTERNAL && pdata->ext_cd_cleanup) 475 pdata->ext_cd_cleanup(&sdhci_s3c_notify_change); 476 477 if (sc->ext_cd_irq) 478 free_irq(sc->ext_cd_irq, sc); 479 480 if (gpio_is_valid(sc->ext_cd_gpio)) 481 gpio_free(sc->ext_cd_gpio); 482 483 sdhci_remove_host(host, 1); 484 485 for (ptr = 0; ptr < 3; ptr++) { 486 if (sc->clk_bus[ptr]) { 487 clk_disable(sc->clk_bus[ptr]); 488 clk_put(sc->clk_bus[ptr]); 489 } 490 } 491 clk_disable(sc->clk_io); 492 clk_put(sc->clk_io); 493 494 iounmap(host->ioaddr); 495 release_resource(sc->ioarea); 496 kfree(sc->ioarea); 497 498 sdhci_free_host(host); 499 platform_set_drvdata(pdev, NULL); 500 501 return 0; 502} 503 504#ifdef CONFIG_PM 505 506static int sdhci_s3c_suspend(struct platform_device *dev, pm_message_t pm) 507{ 508 struct sdhci_host *host = platform_get_drvdata(dev); 509 510 sdhci_suspend_host(host, pm); 511 return 0; 512} 513 514static int sdhci_s3c_resume(struct platform_device *dev) 515{ 516 struct sdhci_host *host = platform_get_drvdata(dev); 517 518 sdhci_resume_host(host); 519 return 0; 520} 521 522#else 523#define sdhci_s3c_suspend NULL 524#define sdhci_s3c_resume NULL 525#endif 526 527static struct platform_driver sdhci_s3c_driver = { 528 .probe = sdhci_s3c_probe, 529 .remove = __devexit_p(sdhci_s3c_remove), 530 .suspend = sdhci_s3c_suspend, 531 .resume = sdhci_s3c_resume, 532 .driver = { 533 .owner = THIS_MODULE, 534 .name = "s3c-sdhci", 535 }, 536}; 537 538static int __init sdhci_s3c_init(void) 539{ 540 return platform_driver_register(&sdhci_s3c_driver); 541} 542 543static void __exit sdhci_s3c_exit(void) 544{ 545 platform_driver_unregister(&sdhci_s3c_driver); 546} 547 548module_init(sdhci_s3c_init); 549module_exit(sdhci_s3c_exit); 550 551MODULE_DESCRIPTION("Samsung SDHCI (HSMMC) glue"); 552MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>"); 553MODULE_LICENSE("GPL v2"); 554MODULE_ALIAS("platform:s3c-sdhci"); 555