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         if (client->is_ts && adc->ts_pend)
 161                 return -EAGAIN;
 162
 163         spin_lock_irqsave(&adc->lock, flags);
 164
 165         client->channel = channel;
 166         client->nr_samples = nr_samples;
 167
 168         if (client->is_ts)
 169                 adc->ts_pend = client;
 170         else
 171                 list_add_tail(&client->pend, &adc_pending);
 172
 173         if (!adc->cur)
 174                 s3c_adc_try(adc);
 175
 176         spin_unlock_irqrestore(&adc->lock, flags);
 177
 178         return 0;
 179 }
 180 EXPORT_SYMBOL_GPL(s3c_adc_start);
 181
 182 static void s3c_convert_done(struct s3c_adc_client *client,
 183                              unsigned v, unsigned u, unsigned *left)
 184 {
 185         client->result = v;
 186         wake_up(client->wait);
 187 }
 188
 189 int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch)
 190 {
 191         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
 192         int ret;
 193
 194         client->convert_cb = s3c_convert_done;
 195         client->wait = &wake;
 196         client->result = -1;
 197
 198         ret = s3c_adc_start(client, ch, 1);
 199         if (ret < 0)
 200                 goto err;
 201
 202         ret = wait_event_timeout(wake, client->result >= 0, HZ / 2);
 203         if (client->result < 0) {
 204                 ret = -ETIMEDOUT;
 205                 goto err;
 206         }
 207
 208         client->convert_cb = NULL;
 209         return client->result;
 210
 211 err:
 212         return ret;
 213 }
 214 EXPORT_SYMBOL_GPL(s3c_adc_read);
 215
 216 static void s3c_adc_default_select(struct s3c_adc_client *client,
 217                                    unsigned select)
 218 {
 219 }
 220
 221 struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
 222                                         void (*select)(struct s3c_adc_client *client,
 223                                                        unsigned int selected),
 224                                         void (*conv)(struct s3c_adc_client *client,
 225                                                      unsigned d0, unsigned d1,
 226                                                      unsigned *samples_left),
 227                                         unsigned int is_ts)
 228 {
 229         struct s3c_adc_client *client;
 230
 231         WARN_ON(!pdev);
 232
 233         if (!select)
 234                 select = s3c_adc_default_select;
 235
 236         if (!pdev)
 237                 return ERR_PTR(-EINVAL);
 238
 239         client = kzalloc(sizeof(struct s3c_adc_client), GFP_KERNEL);
 240         if (!client) {
 241                 dev_err(&pdev->dev, "no memory for adc client\n");
 242                 return ERR_PTR(-ENOMEM);
 243         }
 244
 245         client->pdev = pdev;
 246         client->is_ts = is_ts;
 247         client->select_cb = select;
 248         client->convert_cb = conv;
 249
 250         return client;
 251 }
 252 EXPORT_SYMBOL_GPL(s3c_adc_register);
 253
 254 void s3c_adc_release(struct s3c_adc_client *client)
 255 {
 256         unsigned long flags;
 257
 258         spin_lock_irqsave(&adc_dev->lock, flags);
 259
 260         /* We should really check that nothing is in progress. */
 261         if (adc_dev->cur == client)
 262                 adc_dev->cur = NULL;
 263         if (adc_dev->ts_pend == client)
 264                 adc_dev->ts_pend = NULL;
 265         else {
 266                 struct list_head *p, *n;
 267                 struct s3c_adc_client *tmp;
 268
 269                 list_for_each_safe(p, n, &adc_pending) {
 270                         tmp = list_entry(p, struct s3c_adc_client, pend);
 271                         if (tmp == client)
 272                                 list_del(&tmp->pend);
 273                 }
 274         }
 275
 276         if (adc_dev->cur == NULL)
 277                 s3c_adc_try(adc_dev);
 278
 279         spin_unlock_irqrestore(&adc_dev->lock, flags);
 280         kfree(client);
 281 }
 282 EXPORT_SYMBOL_GPL(s3c_adc_release);
 283
 284 static irqreturn_t s3c_adc_irq(int irq, void *pw)
 285 {
 286         struct adc_device *adc = pw;
 287         struct s3c_adc_client *client = adc->cur;
 288         enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data;
 289         unsigned data0, data1;
 290
 291         if (!client) {
 292                 dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__);
 293                 goto exit;
 294         }
 295
 296         data0 = readl(adc->regs + S3C2410_ADCDAT0);
 297         data1 = readl(adc->regs + S3C2410_ADCDAT1);
 298         adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);
 299
 300         client->nr_samples--;
 301
 302         if (cpu == TYPE_ADCV1 || cpu == TYPE_ADCV11) {
 303                 data0 &= 0x3ff;
 304                 data1 &= 0x3ff;
 305         } else {
 306                 /* S3C2416/S3C64XX/S5P ADC resolution is 12-bit */
 307                 data0 &= 0xfff;
 308                 data1 &= 0xfff;
 309         }
 310
 311         if (client->convert_cb)
 312                 (client->convert_cb)(client, data0, data1, &client->nr_samples);
 313
 314         if (client->nr_samples > 0) {
 315                 /* fire another conversion for this */
 316
 317                 client->select_cb(client, 1);
 318                 s3c_adc_convert(adc);
 319         } else {
 320                 spin_lock(&adc->lock);
 321                 (client->select_cb)(client, 0);
 322                 adc->cur = NULL;
 323
 324                 s3c_adc_try(adc);
 325                 spin_unlock(&adc->lock);
 326         }
 327
 328 exit:
 329         if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3) {
 330                 /* Clear ADC interrupt */
 331                 writel(0, adc->regs + S3C64XX_ADCCLRINT);
 332         }
 333         return IRQ_HANDLED;
 334 }
 335
 336 static int s3c_adc_probe(struct platform_device *pdev)
 337 {
 338         struct device *dev = &pdev->dev;
 339         struct adc_device *adc;
 340         struct resource *regs;
 341         enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data;
 342         int ret;
 343         unsigned tmp;
 344
 345         adc = kzalloc(sizeof(struct adc_device), GFP_KERNEL);
 346         if (adc == NULL) {
 347                 dev_err(dev, "failed to allocate adc_device\n");
 348                 return -ENOMEM;
 349         }
 350
 351         spin_lock_init(&adc->lock);
 352
 353         adc->pdev = pdev;
 354         adc->prescale = S3C2410_ADCCON_PRSCVL(49);
 355
 356         adc->vdd = regulator_get(dev, "vdd");
 357         if (IS_ERR(adc->vdd)) {
 358                 dev_err(dev, "operating without regulator \"vdd\" .\n");
 359                 ret = PTR_ERR(adc->vdd);
 360                 goto err_alloc;
 361         }
 362
 363         adc->irq = platform_get_irq(pdev, 1);
 364         if (adc->irq <= 0) {
 365                 dev_err(dev, "failed to get adc irq\n");
 366                 ret = -ENOENT;
 367                 goto err_reg;
 368         }
 369
 370         ret = request_irq(adc->irq, s3c_adc_irq, 0, dev_name(dev), adc);
 371         if (ret < 0) {
 372                 dev_err(dev, "failed to attach adc irq\n");
 373                 goto err_reg;
 374         }
 375
 376         adc->clk = clk_get(dev, "adc");
 377         if (IS_ERR(adc->clk)) {
 378                 dev_err(dev, "failed to get adc clock\n");
 379                 ret = PTR_ERR(adc->clk);
 380                 goto err_irq;
 381         }
 382
 383         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 384         if (!regs) {
 385                 dev_err(dev, "failed to find registers\n");
 386                 ret = -ENXIO;
 387                 goto err_clk;
 388         }
 389
 390         adc->regs = ioremap(regs->start, resource_size(regs));
 391         if (!adc->regs) {
 392                 dev_err(dev, "failed to map registers\n");
 393                 ret = -ENXIO;
 394                 goto err_clk;
 395         }
 396
 397         ret = regulator_enable(adc->vdd);
 398         if (ret)
 399                 goto err_ioremap;
 400
 401         clk_enable(adc->clk);
 402
 403         tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;
 404
 405         /* Enable 12-bit ADC resolution */
 406         if (cpu == TYPE_ADCV12)
 407                 tmp |= S3C2416_ADCCON_RESSEL;
 408         if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3)
 409                 tmp |= S3C64XX_ADCCON_RESSEL;
 410
 411         writel(tmp, adc->regs + S3C2410_ADCCON);
 412
 413         dev_info(dev, "attached adc driver\n");
 414
 415         platform_set_drvdata(pdev, adc);
 416         adc_dev = adc;
 417
 418         return 0;
 419
 420  err_ioremap:
 421         iounmap(adc->regs);
 422  err_clk:
 423         clk_put(adc->clk);
 424
 425  err_irq:
 426         free_irq(adc->irq, adc);
 427  err_reg:
 428         regulator_put(adc->vdd);
 429  err_alloc:
 430         kfree(adc);
 431         return ret;
 432 }
 433
 434 static int __devexit s3c_adc_remove(struct platform_device *pdev)
 435 {
 436         struct adc_device *adc = platform_get_drvdata(pdev);
 437
 438         iounmap(adc->regs);
 439         free_irq(adc->irq, adc);
 440         clk_disable(adc->clk);
 441         regulator_disable(adc->vdd);
 442         regulator_put(adc->vdd);
 443         clk_put(adc->clk);
 444         kfree(adc);
 445
 446         return 0;
 447 }
 448
 449 #ifdef CONFIG_PM
 450 static int s3c_adc_suspend(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         unsigned long flags;
 456         u32 con;
 457
 458         spin_lock_irqsave(&adc->lock, flags);
 459
 460         con = readl(adc->regs + S3C2410_ADCCON);
 461         con |= S3C2410_ADCCON_STDBM;
 462         writel(con, adc->regs + S3C2410_ADCCON);
 463
 464         disable_irq(adc->irq);
 465         spin_unlock_irqrestore(&adc->lock, flags);
 466         clk_disable(adc->clk);
 467         regulator_disable(adc->vdd);
 468
 469         return 0;
 470 }
 471
 472 static int s3c_adc_resume(struct device *dev)
 473 {
 474         struct platform_device *pdev = container_of(dev,
 475                         struct platform_device, dev);
 476         struct adc_device *adc = platform_get_drvdata(pdev);
 477         enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data;
 478         int ret;
 479         unsigned long tmp;
 480
 481         ret = regulator_enable(adc->vdd);
 482         if (ret)
 483                 return ret;
 484         clk_enable(adc->clk);
 485         enable_irq(adc->irq);
 486
 487         tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;
 488
 489         /* Enable 12-bit ADC resolution */
 490         if (cpu == TYPE_ADCV12)
 491                 tmp |= S3C2416_ADCCON_RESSEL;
 492         if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3)
 493                 tmp |= S3C64XX_ADCCON_RESSEL;
 494
 495         writel(tmp, adc->regs + S3C2410_ADCCON);
 496
 497         return 0;
 498 }
 499
 500 #else
 501 #define s3c_adc_suspend NULL
 502 #define s3c_adc_resume NULL
 503 #endif
 504
 505 static struct platform_device_id s3c_adc_driver_ids[] = {
 506         {
 507                 .name           = "s3c24xx-adc",
 508                 .driver_data    = TYPE_ADCV1,
 509         }, {
 510                 .name           = "s3c2443-adc",
 511                 .driver_data    = TYPE_ADCV11,
 512         }, {
 513                 .name           = "s3c2416-adc",
 514                 .driver_data    = TYPE_ADCV12,
 515         }, {
 516                 .name           = "s3c64xx-adc",
 517                 .driver_data    = TYPE_ADCV2,
 518         }, {
 519                 .name           = "samsung-adc-v3",
 520                 .driver_data    = TYPE_ADCV3,
 521         },
 522         { }
 523 };
 524 MODULE_DEVICE_TABLE(platform, s3c_adc_driver_ids);
 525
 526 static const struct dev_pm_ops adc_pm_ops = {
 527         .suspend        = s3c_adc_suspend,
 528         .resume         = s3c_adc_resume,
 529 };
 530
 531 static struct platform_driver s3c_adc_driver = {
 532         .id_table       = s3c_adc_driver_ids,
 533         .driver         = {
 534                 .name   = "s3c-adc",
 535                 .owner  = THIS_MODULE,
 536                 .pm     = &adc_pm_ops,
 537         },
 538         .probe          = s3c_adc_probe,
 539         .remove         = __devexit_p(s3c_adc_remove),
 540 };
 541
 542 static int __init adc_init(void)
 543 {
 544         int ret;
 545
 546         ret = platform_driver_register(&s3c_adc_driver);
 547         if (ret)
 548                 printk(KERN_ERR "%s: failed to add adc driver\n", __func__);
 549
 550         return ret;
 551 }
 552
 553 module_init(adc_init);