drivers/mfd/ezx-pcap.c

   1 /*
   2  * Driver for Motorola PCAP2 as present in EZX phones
   3  *
   4  * Copyright (C) 2006 Harald Welte <laforge@openezx.org>
   5  * Copyright (C) 2009 Daniel Ribeiro <drwyrm@gmail.com>
   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 version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/irq.h>
  18 #include <linux/mfd/ezx-pcap.h>
  19 #include <linux/spi/spi.h>
  20 #include <linux/gpio.h>
  21 #include <linux/slab.h>
  22
  23 #define PCAP_ADC_MAXQ           8
  24 struct pcap_adc_request {
  25         u8 bank;
  26         u8 ch[2];
  27         u32 flags;
  28         void (*callback)(void *, u16[]);
  29         void *data;
  30 };
  31
  32 struct pcap_adc_sync_request {
  33         u16 res[2];
  34         struct completion completion;
  35 };
  36
  37 struct pcap_chip {
  38         struct spi_device *spi;
  39
  40         /* IO */
  41         u32 buf;
  42         struct mutex io_mutex;
  43
  44         /* IRQ */
  45         unsigned int irq_base;
  46         u32 msr;
  47         struct work_struct isr_work;
  48         struct work_struct msr_work;
  49         struct workqueue_struct *workqueue;
  50
  51         /* ADC */
  52         struct pcap_adc_request *adc_queue[PCAP_ADC_MAXQ];
  53         u8 adc_head;
  54         u8 adc_tail;
  55         struct mutex adc_mutex;
  56 };
  57
  58 /* IO */
  59 static int ezx_pcap_putget(struct pcap_chip *pcap, u32 *data)
  60 {
  61         struct spi_transfer t;
  62         struct spi_message m;
  63         int status;
  64
  65         memset(&t, 0, sizeof t);
  66         spi_message_init(&m);
  67         t.len = sizeof(u32);
  68         spi_message_add_tail(&t, &m);
  69
  70         pcap->buf = *data;
  71         t.tx_buf = (u8 *) &pcap->buf;
  72         t.rx_buf = (u8 *) &pcap->buf;
  73         status = spi_sync(pcap->spi, &m);
  74
  75         if (status == 0)
  76                 *data = pcap->buf;
  77
  78         return status;
  79 }
  80
  81 int ezx_pcap_write(struct pcap_chip *pcap, u8 reg_num, u32 value)
  82 {
  83         int ret;
  84
  85         mutex_lock(&pcap->io_mutex);
  86         value &= PCAP_REGISTER_VALUE_MASK;
  87         value |= PCAP_REGISTER_WRITE_OP_BIT
  88                 | (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
  89         ret = ezx_pcap_putget(pcap, &value);
  90         mutex_unlock(&pcap->io_mutex);
  91
  92         return ret;
  93 }
  94 EXPORT_SYMBOL_GPL(ezx_pcap_write);
  95
  96 int ezx_pcap_read(struct pcap_chip *pcap, u8 reg_num, u32 *value)
  97 {
  98         int ret;
  99
 100         mutex_lock(&pcap->io_mutex);
 101         *value = PCAP_REGISTER_READ_OP_BIT
 102                 | (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
 103
 104         ret = ezx_pcap_putget(pcap, value);
 105         mutex_unlock(&pcap->io_mutex);
 106
 107         return ret;
 108 }
 109 EXPORT_SYMBOL_GPL(ezx_pcap_read);
 110
 111 int ezx_pcap_set_bits(struct pcap_chip *pcap, u8 reg_num, u32 mask, u32 val)
 112 {
 113         int ret;
 114         u32 tmp = PCAP_REGISTER_READ_OP_BIT |
 115                 (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
 116
 117         mutex_lock(&pcap->io_mutex);
 118         ret = ezx_pcap_putget(pcap, &tmp);
 119         if (ret)
 120                 goto out_unlock;
 121
 122         tmp &= (PCAP_REGISTER_VALUE_MASK & ~mask);
 123         tmp |= (val & mask) | PCAP_REGISTER_WRITE_OP_BIT |
 124                 (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
 125
 126         ret = ezx_pcap_putget(pcap, &tmp);
 127 out_unlock:
 128         mutex_unlock(&pcap->io_mutex);
 129
 130         return ret;
 131 }
 132 EXPORT_SYMBOL_GPL(ezx_pcap_set_bits);
 133
 134 /* IRQ */
 135 int irq_to_pcap(struct pcap_chip *pcap, int irq)
 136 {
 137         return irq - pcap->irq_base;
 138 }
 139 EXPORT_SYMBOL_GPL(irq_to_pcap);
 140
 141 int pcap_to_irq(struct pcap_chip *pcap, int irq)
 142 {
 143         return pcap->irq_base + irq;
 144 }
 145 EXPORT_SYMBOL_GPL(pcap_to_irq);
 146
 147 static void pcap_mask_irq(struct irq_data *d)
 148 {
 149         struct pcap_chip *pcap = irq_data_get_irq_chip_data(d);
 150
 151         pcap->msr |= 1 << irq_to_pcap(pcap, d->irq);
 152         queue_work(pcap->workqueue, &pcap->msr_work);
 153 }
 154
 155 static void pcap_unmask_irq(struct irq_data *d)
 156 {
 157         struct pcap_chip *pcap = irq_data_get_irq_chip_data(d);
 158
 159         pcap->msr &= ~(1 << irq_to_pcap(pcap, d->irq));
 160         queue_work(pcap->workqueue, &pcap->msr_work);
 161 }
 162
 163 static struct irq_chip pcap_irq_chip = {
 164         .name           = "pcap",
 165         .irq_mask       = pcap_mask_irq,
 166         .irq_unmask     = pcap_unmask_irq,
 167 };
 168
 169 static void pcap_msr_work(struct work_struct *work)
 170 {
 171         struct pcap_chip *pcap = container_of(work, struct pcap_chip, msr_work);
 172
 173         ezx_pcap_write(pcap, PCAP_REG_MSR, pcap->msr);
 174 }
 175
 176 static void pcap_isr_work(struct work_struct *work)
 177 {
 178         struct pcap_chip *pcap = container_of(work, struct pcap_chip, isr_work);
 179         struct pcap_platform_data *pdata = pcap->spi->dev.platform_data;
 180         u32 msr, isr, int_sel, service;
 181         int irq;
 182
 183         do {
 184                 ezx_pcap_read(pcap, PCAP_REG_MSR, &msr);
 185                 ezx_pcap_read(pcap, PCAP_REG_ISR, &isr);
 186
 187                 /* We cant service/ack irqs that are assigned to port 2 */
 188                 if (!(pdata->config & PCAP_SECOND_PORT)) {
 189                         ezx_pcap_read(pcap, PCAP_REG_INT_SEL, &int_sel);
 190                         isr &= ~int_sel;
 191                 }
 192
 193                 ezx_pcap_write(pcap, PCAP_REG_MSR, isr | msr);
 194                 ezx_pcap_write(pcap, PCAP_REG_ISR, isr);
 195
 196                 local_irq_disable();
 197                 service = isr & ~msr;
 198                 for (irq = pcap->irq_base; service; service >>= 1, irq++) {
 199                         if (service & 1) {
 200                                 struct irq_desc *desc = irq_to_desc(irq);
 201
 202                                 if (WARN(!desc, "Invalid PCAP IRQ %d\n", irq))
 203                                         break;
 204
 205                                 if (desc->status & IRQ_DISABLED)
 206                                         note_interrupt(irq, desc, IRQ_NONE);
 207                                 else
 208                                         desc->handle_irq(irq, desc);
 209                         }
 210                 }
 211                 local_irq_enable();
 212                 ezx_pcap_write(pcap, PCAP_REG_MSR, pcap->msr);
 213         } while (gpio_get_value(irq_to_gpio(pcap->spi->irq)));
 214 }
 215
 216 static void pcap_irq_handler(unsigned int irq, struct irq_desc *desc)
 217 {
 218         struct pcap_chip *pcap = get_irq_data(irq);
 219
 220         desc->irq_data.chip->irq_ack(&desc->irq_data);
 221         queue_work(pcap->workqueue, &pcap->isr_work);
 222         return;
 223 }
 224
 225 /* ADC */
 226 void pcap_set_ts_bits(struct pcap_chip *pcap, u32 bits)
 227 {
 228         u32 tmp;
 229
 230         mutex_lock(&pcap->adc_mutex);
 231         ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
 232         tmp &= ~(PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
 233         tmp |= bits & (PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
 234         ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
 235         mutex_unlock(&pcap->adc_mutex);
 236 }
 237 EXPORT_SYMBOL_GPL(pcap_set_ts_bits);
 238
 239 static void pcap_disable_adc(struct pcap_chip *pcap)
 240 {
 241         u32 tmp;
 242
 243         ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
 244         tmp &= ~(PCAP_ADC_ADEN|PCAP_ADC_BATT_I_ADC|PCAP_ADC_BATT_I_POLARITY);
 245         ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
 246 }
 247
 248 static void pcap_adc_trigger(struct pcap_chip *pcap)
 249 {
 250         u32 tmp;
 251         u8 head;
 252
 253         mutex_lock(&pcap->adc_mutex);
 254         head = pcap->adc_head;
 255         if (!pcap->adc_queue[head]) {
 256                 /* queue is empty, save power */
 257                 pcap_disable_adc(pcap);
 258                 mutex_unlock(&pcap->adc_mutex);
 259                 return;
 260         }
 261         /* start conversion on requested bank, save TS_M bits */
 262         ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
 263         tmp &= (PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
 264         tmp |= pcap->adc_queue[head]->flags | PCAP_ADC_ADEN;
 265
 266         if (pcap->adc_queue[head]->bank == PCAP_ADC_BANK_1)
 267                 tmp |= PCAP_ADC_AD_SEL1;
 268
 269         ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
 270         mutex_unlock(&pcap->adc_mutex);
 271         ezx_pcap_write(pcap, PCAP_REG_ADR, PCAP_ADR_ASC);
 272 }
 273
 274 static irqreturn_t pcap_adc_irq(int irq, void *_pcap)
 275 {
 276         struct pcap_chip *pcap = _pcap;
 277         struct pcap_adc_request *req;
 278         u16 res[2];
 279         u32 tmp;
 280
 281         mutex_lock(&pcap->adc_mutex);
 282         req = pcap->adc_queue[pcap->adc_head];
 283
 284         if (WARN(!req, "adc irq without pending request\n")) {
 285                 mutex_unlock(&pcap->adc_mutex);
 286                 return IRQ_HANDLED;
 287         }
 288
 289         /* read requested channels results */
 290         ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
 291         tmp &= ~(PCAP_ADC_ADA1_MASK | PCAP_ADC_ADA2_MASK);
 292         tmp |= (req->ch[0] << PCAP_ADC_ADA1_SHIFT);
 293         tmp |= (req->ch[1] << PCAP_ADC_ADA2_SHIFT);
 294         ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
 295         ezx_pcap_read(pcap, PCAP_REG_ADR, &tmp);
 296         res[0] = (tmp & PCAP_ADR_ADD1_MASK) >> PCAP_ADR_ADD1_SHIFT;
 297         res[1] = (tmp & PCAP_ADR_ADD2_MASK) >> PCAP_ADR_ADD2_SHIFT;
 298
 299         pcap->adc_queue[pcap->adc_head] = NULL;
 300         pcap->adc_head = (pcap->adc_head + 1) & (PCAP_ADC_MAXQ - 1);
 301         mutex_unlock(&pcap->adc_mutex);
 302
 303         /* pass the results and release memory */
 304         req->callback(req->data, res);
 305         kfree(req);
 306
 307         /* trigger next conversion (if any) on queue */
 308         pcap_adc_trigger(pcap);
 309
 310         return IRQ_HANDLED;
 311 }
 312
 313 int pcap_adc_async(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
 314                                                 void *callback, void *data)
 315 {
 316         struct pcap_adc_request *req;
 317
 318         /* This will be freed after we have a result */
 319         req = kmalloc(sizeof(struct pcap_adc_request), GFP_KERNEL);
 320         if (!req)
 321                 return -ENOMEM;
 322
 323         req->bank = bank;
 324         req->flags = flags;
 325         req->ch[0] = ch[0];
 326         req->ch[1] = ch[1];
 327         req->callback = callback;
 328         req->data = data;
 329
 330         mutex_lock(&pcap->adc_mutex);
 331         if (pcap->adc_queue[pcap->adc_tail]) {
 332                 mutex_unlock(&pcap->adc_mutex);
 333                 kfree(req);
 334                 return -EBUSY;
 335         }
 336         pcap->adc_queue[pcap->adc_tail] = req;
 337         pcap->adc_tail = (pcap->adc_tail + 1) & (PCAP_ADC_MAXQ - 1);
 338         mutex_unlock(&pcap->adc_mutex);
 339
 340         /* start conversion */
 341         pcap_adc_trigger(pcap);
 342
 343         return 0;
 344 }
 345 EXPORT_SYMBOL_GPL(pcap_adc_async);
 346
 347 static void pcap_adc_sync_cb(void *param, u16 res[])
 348 {
 349         struct pcap_adc_sync_request *req = param;
 350
 351         req->res[0] = res[0];
 352         req->res[1] = res[1];
 353         complete(&req->completion);
 354 }
 355
 356 int pcap_adc_sync(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
 357                                                                 u16 res[])
 358 {
 359         struct pcap_adc_sync_request sync_data;
 360         int ret;
 361
 362         init_completion(&sync_data.completion);
 363         ret = pcap_adc_async(pcap, bank, flags, ch, pcap_adc_sync_cb,
 364                                                                 &sync_data);
 365         if (ret)
 366                 return ret;
 367         wait_for_completion(&sync_data.completion);
 368         res[0] = sync_data.res[0];
 369         res[1] = sync_data.res[1];
 370
 371         return 0;
 372 }
 373 EXPORT_SYMBOL_GPL(pcap_adc_sync);
 374
 375 /* subdevs */
 376 static int pcap_remove_subdev(struct device *dev, void *unused)
 377 {
 378         platform_device_unregister(to_platform_device(dev));
 379         return 0;
 380 }
 381
 382 static int __devinit pcap_add_subdev(struct pcap_chip *pcap,
 383                                                 struct pcap_subdev *subdev)
 384 {
 385         struct platform_device *pdev;
 386         int ret;
 387
 388         pdev = platform_device_alloc(subdev->name, subdev->id);
 389         if (!pdev)
 390                 return -ENOMEM;
 391
 392         pdev->dev.parent = &pcap->spi->dev;
 393         pdev->dev.platform_data = subdev->platform_data;
 394
 395         ret = platform_device_add(pdev);
 396         if (ret)
 397                 platform_device_put(pdev);
 398
 399         return ret;
 400 }
 401
 402 static int __devexit ezx_pcap_remove(struct spi_device *spi)
 403 {
 404         struct pcap_chip *pcap = dev_get_drvdata(&spi->dev);
 405         struct pcap_platform_data *pdata = spi->dev.platform_data;
 406         int i, adc_irq;
 407
 408         /* remove all registered subdevs */
 409         device_for_each_child(&spi->dev, NULL, pcap_remove_subdev);
 410
 411         /* cleanup ADC */
 412         adc_irq = pcap_to_irq(pcap, (pdata->config & PCAP_SECOND_PORT) ?
 413                                 PCAP_IRQ_ADCDONE2 : PCAP_IRQ_ADCDONE);
 414         free_irq(adc_irq, pcap);
 415         mutex_lock(&pcap->adc_mutex);
 416         for (i = 0; i < PCAP_ADC_MAXQ; i++)
 417                 kfree(pcap->adc_queue[i]);
 418         mutex_unlock(&pcap->adc_mutex);
 419
 420         /* cleanup irqchip */
 421         for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++)
 422                 set_irq_chip_and_handler(i, NULL, NULL);
 423
 424         destroy_workqueue(pcap->workqueue);
 425
 426         kfree(pcap);
 427
 428         return 0;
 429 }
 430
 431 static int __devinit ezx_pcap_probe(struct spi_device *spi)
 432 {
 433         struct pcap_platform_data *pdata = spi->dev.platform_data;
 434         struct pcap_chip *pcap;
 435         int i, adc_irq;
 436         int ret = -ENODEV;
 437
 438         /* platform data is required */
 439         if (!pdata)
 440                 goto ret;
 441
 442         pcap = kzalloc(sizeof(*pcap), GFP_KERNEL);
 443         if (!pcap) {
 444                 ret = -ENOMEM;
 445                 goto ret;
 446         }
 447
 448         mutex_init(&pcap->io_mutex);
 449         mutex_init(&pcap->adc_mutex);
 450         INIT_WORK(&pcap->isr_work, pcap_isr_work);
 451         INIT_WORK(&pcap->msr_work, pcap_msr_work);
 452         dev_set_drvdata(&spi->dev, pcap);
 453
 454         /* setup spi */
 455         spi->bits_per_word = 32;
 456         spi->mode = SPI_MODE_0 | (pdata->config & PCAP_CS_AH ? SPI_CS_HIGH : 0);
 457         ret = spi_setup(spi);
 458         if (ret)
 459                 goto free_pcap;
 460
 461         pcap->spi = spi;
 462
 463         /* setup irq */
 464         pcap->irq_base = pdata->irq_base;
 465         pcap->workqueue = create_singlethread_workqueue("pcapd");
 466         if (!pcap->workqueue) {
 467                 ret = -ENOMEM;
 468                 dev_err(&spi->dev, "cant create pcap thread\n");
 469                 goto free_pcap;
 470         }
 471
 472         /* redirect interrupts to AP, except adcdone2 */
 473         if (!(pdata->config & PCAP_SECOND_PORT))
 474                 ezx_pcap_write(pcap, PCAP_REG_INT_SEL,
 475                                         (1 << PCAP_IRQ_ADCDONE2));
 476
 477         /* setup irq chip */
 478         for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++) {
 479                 set_irq_chip_and_handler(i, &pcap_irq_chip, handle_simple_irq);
 480                 set_irq_chip_data(i, pcap);
 481 #ifdef CONFIG_ARM
 482                 set_irq_flags(i, IRQF_VALID);
 483 #else
 484                 set_irq_noprobe(i);
 485 #endif
 486         }
 487
 488         /* mask/ack all PCAP interrupts */
 489         ezx_pcap_write(pcap, PCAP_REG_MSR, PCAP_MASK_ALL_INTERRUPT);
 490         ezx_pcap_write(pcap, PCAP_REG_ISR, PCAP_CLEAR_INTERRUPT_REGISTER);
 491         pcap->msr = PCAP_MASK_ALL_INTERRUPT;
 492
 493         set_irq_type(spi->irq, IRQ_TYPE_EDGE_RISING);
 494         set_irq_data(spi->irq, pcap);
 495         set_irq_chained_handler(spi->irq, pcap_irq_handler);
 496         set_irq_wake(spi->irq, 1);
 497
 498         /* ADC */
 499         adc_irq = pcap_to_irq(pcap, (pdata->config & PCAP_SECOND_PORT) ?
 500                                         PCAP_IRQ_ADCDONE2 : PCAP_IRQ_ADCDONE);
 501
 502         ret = request_irq(adc_irq, pcap_adc_irq, 0, "ADC", pcap);
 503         if (ret)
 504                 goto free_irqchip;
 505
 506         /* setup subdevs */
 507         for (i = 0; i < pdata->num_subdevs; i++) {
 508                 ret = pcap_add_subdev(pcap, &pdata->subdevs[i]);
 509                 if (ret)
 510                         goto remove_subdevs;
 511         }
 512
 513         /* board specific quirks */
 514         if (pdata->init)
 515                 pdata->init(pcap);
 516
 517         return 0;
 518
 519 remove_subdevs:
 520         device_for_each_child(&spi->dev, NULL, pcap_remove_subdev);
 521 /* free_adc: */
 522         free_irq(adc_irq, pcap);
 523 free_irqchip:
 524         for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++)
 525                 set_irq_chip_and_handler(i, NULL, NULL);
 526 /* destroy_workqueue: */
 527         destroy_workqueue(pcap->workqueue);
 528 free_pcap:
 529         kfree(pcap);
 530 ret:
 531         return ret;
 532 }
 533
 534 static struct spi_driver ezxpcap_driver = {
 535         .probe  = ezx_pcap_probe,
 536         .remove = __devexit_p(ezx_pcap_remove),
 537         .driver = {
 538                 .name   = "ezx-pcap",
 539                 .owner  = THIS_MODULE,
 540         },
 541 };
 542
 543 static int __init ezx_pcap_init(void)
 544 {
 545         return spi_register_driver(&ezxpcap_driver);
 546 }
 547
 548 static void __exit ezx_pcap_exit(void)
 549 {
 550         spi_unregister_driver(&ezxpcap_driver);
 551 }
 552
 553 subsys_initcall(ezx_pcap_init);
 554 module_exit(ezx_pcap_exit);
 555
 556 MODULE_LICENSE("GPL");
 557 MODULE_AUTHOR("Daniel Ribeiro / Harald Welte");
 558 MODULE_DESCRIPTION("Motorola PCAP2 ASIC Driver");
 559 MODULE_ALIAS("spi:ezx-pcap");