arch/arm/plat-samsung/adc.c

   1 /* arch/arm/plat-samsung/adc.c
   2  *
   3  * Copyright (c) 2008 Simtec Electronics
   4  *      http://armlinux.simtec.co.uk/
   5  *      Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org>
   6  *
   7  * Samsung ADC device core
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License.
  12 */
  13
  14 #include <linux/module.h>
  15 #include <linux/kernel.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/sched.h>
  18 #include <linux/list.h>
  19 #include <linux/slab.h>
  20 #include <linux/err.h>
  21 #include <linux/clk.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/io.h>
  24 #include <linux/regulator/consumer.h>
  25
  26 #include <plat/regs-adc.h>
  27 #include <plat/adc.h>
  28
  29 /* This driver is designed to control the usage of the ADC block between
  30  * the touchscreen and any other drivers that may need to use it, such as
  31  * the hwmon driver.
  32  *
  33  * Priority will be given to the touchscreen driver, but as this itself is
  34  * rate limited it should not starve other requests which are processed in
  35  * order that they are received.
  36  *
  37  * Each user registers to get a client block which uniquely identifies it
  38  * and stores information such as the necessary functions to callback when
  39  * action is required.
  40  */
  41
  42 enum s3c_cpu_type {
  43         TYPE_ADCV1, /* S3C24XX */
  44         TYPE_ADCV11, /* S3C2443 */
  45         TYPE_ADCV12, /* S3C2416, S3C2450 */
  46         TYPE_ADCV2, /* S3C64XX, S5P64X0, S5PC100 */
  47         TYPE_ADCV3, /* S5PV210, S5PC110, EXYNOS4210 */
  48 };
  49
  50 struct s3c_adc_client {
  51         struct platform_device  *pdev;
  52         struct list_head         pend;
  53         wait_queue_head_t       *wait;
  54
  55         unsigned int             nr_samples;
  56         int                      result;
  57         unsigned char            is_ts;
  58         unsigned char            channel;
  59
  60         void    (*select_cb)(struct s3c_adc_client *c, unsigned selected);
  61         void    (*convert_cb)(struct s3c_adc_client *c,
  62                               unsigned val1, unsigned val2,
  63                               unsigned *samples_left);
  64 };
  65
  66 struct adc_device {
  67         struct platform_device  *pdev;
  68         struct platform_device  *owner;
  69         struct clk              *clk;
  70         struct s3c_adc_client   *cur;
  71         struct s3c_adc_client   *ts_pend;
  72         void __iomem            *regs;
  73         spinlock_t               lock;
  74
  75         unsigned int             prescale;
  76
  77         int                      irq;
  78         struct regulator        *vdd;
  79 };
  80
  81 static struct adc_device *adc_dev;
  82
  83 static LIST_HEAD(adc_pending);  /* protected by adc_device.lock */
  84
  85 #define adc_dbg(_adc, msg...) dev_dbg(&(_adc)->pdev->dev, msg)
  86
  87 static inline void s3c_adc_convert(struct adc_device *adc)
  88 {
  89         unsigned con = readl(adc->regs + S3C2410_ADCCON);
  90
  91         con |= S3C2410_ADCCON_ENABLE_START;
  92         writel(con, adc->regs + S3C2410_ADCCON);
  93 }
  94
  95 static inline void s3c_adc_select(struct adc_device *adc,
  96                                   struct s3c_adc_client *client)
  97 {
  98         unsigned con = readl(adc->regs + S3C2410_ADCCON);
  99         enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data;
 100
 101         client->select_cb(client, 1);
 102
 103         if (cpu == TYPE_ADCV1 || cpu == TYPE_ADCV2)
 104                 con &= ~S3C2410_ADCCON_MUXMASK;
 105         con &= ~S3C2410_ADCCON_STDBM;
 106         con &= ~S3C2410_ADCCON_STARTMASK;
 107
 108         if (!client->is_ts) {
 109                 if (cpu == TYPE_ADCV3)
 110                         writel(client->channel & 0xf, adc->regs + S5P_ADCMUX);
 111                 else if (cpu == TYPE_ADCV11 || cpu == TYPE_ADCV12)
 112                         writel(client->channel & 0xf,
 113                                                 adc->regs + S3C2443_ADCMUX);
 114                 else
 115                         con |= S3C2410_ADCCON_SELMUX(client->channel);
 116         }
 117
 118         writel(con, adc->regs + S3C2410_ADCCON);
 119 }
 120
 121 static void s3c_adc_dbgshow(struct adc_device *adc)
 122 {
 123         adc_dbg(adc, "CON=%08x, TSC=%08x, DLY=%08x\n",
 124                 readl(adc->regs + S3C2410_ADCCON),
 125                 readl(adc->regs + S3C2410_ADCTSC),
 126                 readl(adc->regs + S3C2410_ADCDLY));
 127 }
 128
 129 static void s3c_adc_try(struct adc_device *adc)
 130 {
 131         struct s3c_adc_client *next = adc->ts_pend;
 132
 133         if (!next && !list_empty(&adc_pending)) {
 134                 next = list_first_entry(&adc_pending,
 135                                         struct s3c_adc_client, pend);
 136                 list_del(&next->pend);
 137         } else
 138                 adc->ts_pend = NULL;
 139
 140         if (next) {
 141                 adc_dbg(adc, "new client is %p\n", next);
 142                 adc->cur = next;
 143                 s3c_adc_select(adc, next);
 144                 s3c_adc_convert(adc);
 145                 s3c_adc_dbgshow(adc);
 146         }
 147 }
 148
 149 int s3c_adc_start(struct s3c_adc_client *client,
 150                   unsigned int channel, unsigned int nr_samples)
 151 {
 152         struct adc_device *adc = adc_dev;
 153         unsigned long flags;
 154
 155         if (!adc) {
 156                 printk(KERN_ERR "%s: failed to find adc\n", __func__);
 157                 return -EINVAL;
 158         }
 159
 160         spin_lock_irqsave(&adc->lock, flags);
 161
 162         if (client->is_ts && adc->ts_pend) {
 163                 spin_unlock_irqrestore(&adc->lock, flags);
 164                 return -EAGAIN;
 165         }
 166
 167         client->channel = channel;
 168         client->nr_samples = nr_samples;
 169
 170         if (client->is_ts)
 171                 adc->ts_pend = client;
 172         else
 173                 list_add_tail(&client->pend, &adc_pending);
 174
 175         if (!adc->cur)
 176                 s3c_adc_try(adc);
 177
 178         spin_unlock_irqrestore(&adc->lock, flags);
 179
 180         return 0;
 181 }
 182 EXPORT_SYMBOL_GPL(s3c_adc_start);
 183
 184 static void s3c_convert_done(struct s3c_adc_client *client,
 185                              unsigned v, unsigned u, unsigned *left)
 186 {
 187         client->result = v;
 188         wake_up(client->wait);
 189 }
 190
 191 int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch)
 192 {
 193         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
 194         int ret;
 195
 196         client->convert_cb = s3c_convert_done;
 197         client->wait = &wake;
 198         client->result = -1;
 199
 200         ret = s3c_adc_start(client, ch, 1);
 201         if (ret < 0)
 202                 goto err;
 203
 204         ret = wait_event_timeout(wake, client->result >= 0, HZ / 2);
 205         if (client->result < 0) {
 206                 ret = -ETIMEDOUT;
 207                 goto err;
 208         }
 209
 210         client->convert_cb = NULL;
 211         return client->result;
 212
 213 err:
 214         return ret;
 215 }
 216 EXPORT_SYMBOL_GPL(s3c_adc_read);
 217
 218 static void s3c_adc_default_select(struct s3c_adc_client *client,
 219                                    unsigned select)
 220 {
 221 }
 222
 223 struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
 224                                         void (*select)(struct s3c_adc_client *client,
 225                                                        unsigned int selected),
 226                                         void (*conv)(struct s3c_adc_client *client,
 227                                                      unsigned d0, unsigned d1,
 228                                                      unsigned *samples_left),
 229                                         unsigned int is_ts)
 230 {
 231         struct s3c_adc_client *client;
 232
 233         WARN_ON(!pdev);
 234
 235         if (!select)
 236                 select = s3c_adc_default_select;
 237
 238         if (!pdev)
 239                 return ERR_PTR(-EINVAL);
 240
 241         client = kzalloc(sizeof(struct s3c_adc_client), GFP_KERNEL);
 242         if (!client) {
 243                 dev_err(&pdev->dev, "no memory for adc client\n");
 244                 return ERR_PTR(-ENOMEM);
 245         }
 246
 247         client->pdev = pdev;
 248         client->is_ts = is_ts;
 249         client->select_cb = select;
 250         client->convert_cb = conv;
 251
 252         return client;
 253 }
 254 EXPORT_SYMBOL_GPL(s3c_adc_register);
 255
 256 void s3c_adc_release(struct s3c_adc_client *client)
 257 {
 258         unsigned long flags;
 259
 260         spin_lock_irqsave(&adc_dev->lock, flags);
 261
 262         /* We should really check that nothing is in progress. */
 263         if (adc_dev->cur == client)
 264                 adc_dev->cur = NULL;
 265         if (adc_dev->ts_pend == client)
 266                 adc_dev->ts_pend = NULL;
 267         else {
 268                 struct list_head *p, *n;
 269                 struct s3c_adc_client *tmp;
 270
 271                 list_for_each_safe(p, n, &adc_pending) {
 272                         tmp = list_entry(p, struct s3c_adc_client, pend);
 273                         if (tmp == client)
 274                                 list_del(&tmp->pend);
 275                 }
 276         }
 277
 278         if (adc_dev->cur == NULL)
 279                 s3c_adc_try(adc_dev);
 280
 281         spin_unlock_irqrestore(&adc_dev->lock, flags);
 282         kfree(client);
 283 }
 284 EXPORT_SYMBOL_GPL(s3c_adc_release);
 285
 286 static irqreturn_t s3c_adc_irq(int irq, void *pw)
 287 {
 288         struct adc_device *adc = pw;
 289         struct s3c_adc_client *client = adc->cur;
 290         enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data;
 291         unsigned data0, data1;
 292
 293         if (!client) {
 294                 dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__);
 295                 goto exit;
 296         }
 297
 298         data0 = readl(adc->regs + S3C2410_ADCDAT0);
 299         data1 = readl(adc->regs + S3C2410_ADCDAT1);
 300         adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);
 301
 302         client->nr_samples--;
 303
 304         if (cpu == TYPE_ADCV1 || cpu == TYPE_ADCV11) {
 305                 data0 &= 0x3ff;
 306                 data1 &= 0x3ff;
 307         } else {
 308                 /* S3C2416/S3C64XX/S5P ADC resolution is 12-bit */
 309                 data0 &= 0xfff;
 310                 data1 &= 0xfff;
 311         }
 312
 313         if (client->convert_cb)
 314                 (client->convert_cb)(client, data0, data1, &client->nr_samples);
 315
 316         if (client->nr_samples > 0) {
 317                 /* fire another conversion for this */
 318
 319                 client->select_cb(client, 1);
 320                 s3c_adc_convert(adc);
 321         } else {
 322                 spin_lock(&adc->lock);
 323                 (client->select_cb)(client, 0);
 324                 adc->cur = NULL;
 325
 326                 s3c_adc_try(adc);
 327                 spin_unlock(&adc->lock);
 328         }
 329
 330 exit:
 331         if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3) {
 332                 /* Clear ADC interrupt */
 333                 writel(0, adc->regs + S3C64XX_ADCCLRINT);
 334         }
 335         return IRQ_HANDLED;
 336 }
 337
 338 static int s3c_adc_probe(struct platform_device *pdev)
 339 {
 340         struct device *dev = &pdev->dev;
 341         struct adc_device *adc;
 342         struct resource *regs;
 343         enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data;
 344         int ret;
 345         unsigned tmp;
 346
 347         adc = devm_kzalloc(dev, sizeof(struct adc_device), GFP_KERNEL);
 348         if (adc == NULL) {
 349                 dev_err(dev, "failed to allocate adc_device\n");
 350                 return -ENOMEM;
 351         }
 352
 353         spin_lock_init(&adc->lock);
 354
 355         adc->pdev = pdev;
 356         adc->prescale = S3C2410_ADCCON_PRSCVL(49);
 357
 358         adc->vdd = devm_regulator_get(dev, "vdd");
 359         if (IS_ERR(adc->vdd)) {
 360                 dev_err(dev, "operating without regulator \"vdd\" .\n");
 361                 return PTR_ERR(adc->vdd);
 362         }
 363
 364         adc->irq = platform_get_irq(pdev, 1);
 365         if (adc->irq <= 0) {
 366                 dev_err(dev, "failed to get adc irq\n");
 367                 return -ENOENT;
 368         }
 369
 370         ret = devm_request_irq(dev, adc->irq, s3c_adc_irq, 0, dev_name(dev),
 371                                 adc);
 372         if (ret < 0) {
 373                 dev_err(dev, "failed to attach adc irq\n");
 374                 return ret;
 375         }
 376
 377         adc->clk = devm_clk_get(dev, "adc");
 378         if (IS_ERR(adc->clk)) {
 379                 dev_err(dev, "failed to get adc clock\n");
 380                 return PTR_ERR(adc->clk);
 381         }
 382
 383         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 384         if (!regs) {
 385                 dev_err(dev, "failed to find registers\n");
 386                 return -ENXIO;
 387         }
 388
 389         adc->regs = devm_ioremap_resource(dev, regs);
 390         if (IS_ERR(adc->regs))
 391                 return PTR_ERR(adc->regs);
 392
 393         ret = regulator_enable(adc->vdd);
 394         if (ret)
 395                 return ret;
 396
 397         clk_enable(adc->clk);
 398
 399         tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;
 400
 401         /* Enable 12-bit ADC resolution */
 402         if (cpu == TYPE_ADCV12)
 403                 tmp |= S3C2416_ADCCON_RESSEL;
 404         if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3)
 405                 tmp |= S3C64XX_ADCCON_RESSEL;
 406
 407         writel(tmp, adc->regs + S3C2410_ADCCON);
 408
 409         dev_info(dev, "attached adc driver\n");
 410
 411         platform_set_drvdata(pdev, adc);
 412         adc_dev = adc;
 413
 414         return 0;
 415 }
 416
 417 static int s3c_adc_remove(struct platform_device *pdev)
 418 {
 419         struct adc_device *adc = platform_get_drvdata(pdev);
 420
 421         clk_disable(adc->clk);
 422         regulator_disable(adc->vdd);
 423
 424         return 0;
 425 }
 426
 427 #ifdef CONFIG_PM
 428 static int s3c_adc_suspend(struct device *dev)
 429 {
 430         struct platform_device *pdev = container_of(dev,
 431                         struct platform_device, dev);
 432         struct adc_device *adc = platform_get_drvdata(pdev);
 433         unsigned long flags;
 434         u32 con;
 435
 436         spin_lock_irqsave(&adc->lock, flags);
 437
 438         con = readl(adc->regs + S3C2410_ADCCON);
 439         con |= S3C2410_ADCCON_STDBM;
 440         writel(con, adc->regs + S3C2410_ADCCON);
 441
 442         disable_irq(adc->irq);
 443         spin_unlock_irqrestore(&adc->lock, flags);
 444         clk_disable(adc->clk);
 445         regulator_disable(adc->vdd);
 446
 447         return 0;
 448 }
 449
 450 static int s3c_adc_resume(struct device *dev)
 451 {
 452         struct platform_device *pdev = container_of(dev,
 453                         struct platform_device, dev);
 454         struct adc_device *adc = platform_get_drvdata(pdev);
 455         enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data;
 456         int ret;
 457         unsigned long tmp;
 458
 459         ret = regulator_enable(adc->vdd);
 460         if (ret)
 461                 return ret;
 462         clk_enable(adc->clk);
 463         enable_irq(adc->irq);
 464
 465         tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;
 466
 467         /* Enable 12-bit ADC resolution */
 468         if (cpu == TYPE_ADCV12)
 469                 tmp |= S3C2416_ADCCON_RESSEL;
 470         if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3)
 471                 tmp |= S3C64XX_ADCCON_RESSEL;
 472
 473         writel(tmp, adc->regs + S3C2410_ADCCON);
 474
 475         return 0;
 476 }
 477
 478 #else
 479 #define s3c_adc_suspend NULL
 480 #define s3c_adc_resume NULL
 481 #endif
 482
 483 static struct platform_device_id s3c_adc_driver_ids[] = {
 484         {
 485                 .name           = "s3c24xx-adc",
 486                 .driver_data    = TYPE_ADCV1,
 487         }, {
 488                 .name           = "s3c2443-adc",
 489                 .driver_data    = TYPE_ADCV11,
 490         }, {
 491                 .name           = "s3c2416-adc",
 492                 .driver_data    = TYPE_ADCV12,
 493         }, {
 494                 .name           = "s3c64xx-adc",
 495                 .driver_data    = TYPE_ADCV2,
 496         }, {
 497                 .name           = "samsung-adc-v3",
 498                 .driver_data    = TYPE_ADCV3,
 499         },
 500         { }
 501 };
 502 MODULE_DEVICE_TABLE(platform, s3c_adc_driver_ids);
 503
 504 static const struct dev_pm_ops adc_pm_ops = {
 505         .suspend        = s3c_adc_suspend,
 506         .resume         = s3c_adc_resume,
 507 };
 508
 509 static struct platform_driver s3c_adc_driver = {
 510         .id_table       = s3c_adc_driver_ids,
 511         .driver         = {
 512                 .name   = "s3c-adc",
 513                 .owner  = THIS_MODULE,
 514                 .pm     = &adc_pm_ops,
 515         },
 516         .probe          = s3c_adc_probe,
 517         .remove         = s3c_adc_remove,
 518 };
 519
 520 static int __init adc_init(void)
 521 {
 522         int ret;
 523
 524         ret = platform_driver_register(&s3c_adc_driver);
 525         if (ret)
 526                 printk(KERN_ERR "%s: failed to add adc driver\n", __func__);
 527
 528         return ret;
 529 }
 530
 531 module_init(adc_init);