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_disable    = pcap_mask_irq,
 166         .irq_mask       = pcap_mask_irq,
 167         .irq_unmask     = pcap_unmask_irq,
 168 };
 169
 170 static void pcap_msr_work(struct work_struct *work)
 171 {
 172         struct pcap_chip *pcap = container_of(work, struct pcap_chip, msr_work);
 173
 174         ezx_pcap_write(pcap, PCAP_REG_MSR, pcap->msr);
 175 }
 176
 177 static void pcap_isr_work(struct work_struct *work)
 178 {
 179         struct pcap_chip *pcap = container_of(work, struct pcap_chip, isr_work);
 180         struct pcap_platform_data *pdata = dev_get_platdata(&pcap->spi->dev);
 181         u32 msr, isr, int_sel, service;
 182         int irq;
 183
 184         do {
 185                 ezx_pcap_read(pcap, PCAP_REG_MSR, &msr);
 186                 ezx_pcap_read(pcap, PCAP_REG_ISR, &isr);
 187
 188                 /* We can't service/ack irqs that are assigned to port 2 */
 189                 if (!(pdata->config & PCAP_SECOND_PORT)) {
 190                         ezx_pcap_read(pcap, PCAP_REG_INT_SEL, &int_sel);
 191                         isr &= ~int_sel;
 192                 }
 193
 194                 ezx_pcap_write(pcap, PCAP_REG_MSR, isr | msr);
 195                 ezx_pcap_write(pcap, PCAP_REG_ISR, isr);
 196
 197                 local_irq_disable();
 198                 service = isr & ~msr;
 199                 for (irq = pcap->irq_base; service; service >>= 1, irq++) {
 200                         if (service & 1)
 201                                 generic_handle_irq(irq);
 202                 }
 203                 local_irq_enable();
 204                 ezx_pcap_write(pcap, PCAP_REG_MSR, pcap->msr);
 205         } while (gpio_get_value(pdata->gpio));
 206 }
 207
 208 static void pcap_irq_handler(struct irq_desc *desc)
 209 {
 210         struct pcap_chip *pcap = irq_desc_get_handler_data(desc);
 211
 212         desc->irq_data.chip->irq_ack(&desc->irq_data);
 213         queue_work(pcap->workqueue, &pcap->isr_work);
 214 }
 215
 216 /* ADC */
 217 void pcap_set_ts_bits(struct pcap_chip *pcap, u32 bits)
 218 {
 219         u32 tmp;
 220
 221         mutex_lock(&pcap->adc_mutex);
 222         ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
 223         tmp &= ~(PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
 224         tmp |= bits & (PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
 225         ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
 226         mutex_unlock(&pcap->adc_mutex);
 227 }
 228 EXPORT_SYMBOL_GPL(pcap_set_ts_bits);
 229
 230 static void pcap_disable_adc(struct pcap_chip *pcap)
 231 {
 232         u32 tmp;
 233
 234         ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
 235         tmp &= ~(PCAP_ADC_ADEN|PCAP_ADC_BATT_I_ADC|PCAP_ADC_BATT_I_POLARITY);
 236         ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
 237 }
 238
 239 static void pcap_adc_trigger(struct pcap_chip *pcap)
 240 {
 241         u32 tmp;
 242         u8 head;
 243
 244         mutex_lock(&pcap->adc_mutex);
 245         head = pcap->adc_head;
 246         if (!pcap->adc_queue[head]) {
 247                 /* queue is empty, save power */
 248                 pcap_disable_adc(pcap);
 249                 mutex_unlock(&pcap->adc_mutex);
 250                 return;
 251         }
 252         /* start conversion on requested bank, save TS_M bits */
 253         ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
 254         tmp &= (PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
 255         tmp |= pcap->adc_queue[head]->flags | PCAP_ADC_ADEN;
 256
 257         if (pcap->adc_queue[head]->bank == PCAP_ADC_BANK_1)
 258                 tmp |= PCAP_ADC_AD_SEL1;
 259
 260         ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
 261         mutex_unlock(&pcap->adc_mutex);
 262         ezx_pcap_write(pcap, PCAP_REG_ADR, PCAP_ADR_ASC);
 263 }
 264
 265 static irqreturn_t pcap_adc_irq(int irq, void *_pcap)
 266 {
 267         struct pcap_chip *pcap = _pcap;
 268         struct pcap_adc_request *req;
 269         u16 res[2];
 270         u32 tmp;
 271
 272         mutex_lock(&pcap->adc_mutex);
 273         req = pcap->adc_queue[pcap->adc_head];
 274
 275         if (WARN(!req, "adc irq without pending request\n")) {
 276                 mutex_unlock(&pcap->adc_mutex);
 277                 return IRQ_HANDLED;
 278         }
 279
 280         /* read requested channels results */
 281         ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
 282         tmp &= ~(PCAP_ADC_ADA1_MASK | PCAP_ADC_ADA2_MASK);
 283         tmp |= (req->ch[0] << PCAP_ADC_ADA1_SHIFT);
 284         tmp |= (req->ch[1] << PCAP_ADC_ADA2_SHIFT);
 285         ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
 286         ezx_pcap_read(pcap, PCAP_REG_ADR, &tmp);
 287         res[0] = (tmp & PCAP_ADR_ADD1_MASK) >> PCAP_ADR_ADD1_SHIFT;
 288         res[1] = (tmp & PCAP_ADR_ADD2_MASK) >> PCAP_ADR_ADD2_SHIFT;
 289
 290         pcap->adc_queue[pcap->adc_head] = NULL;
 291         pcap->adc_head = (pcap->adc_head + 1) & (PCAP_ADC_MAXQ - 1);
 292         mutex_unlock(&pcap->adc_mutex);
 293
 294         /* pass the results and release memory */
 295         req->callback(req->data, res);
 296         kfree(req);
 297
 298         /* trigger next conversion (if any) on queue */
 299         pcap_adc_trigger(pcap);
 300
 301         return IRQ_HANDLED;
 302 }
 303
 304 int pcap_adc_async(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
 305                                                 void *callback, void *data)
 306 {
 307         struct pcap_adc_request *req;
 308
 309         /* This will be freed after we have a result */
 310         req = kmalloc(sizeof(struct pcap_adc_request), GFP_KERNEL);
 311         if (!req)
 312                 return -ENOMEM;
 313
 314         req->bank = bank;
 315         req->flags = flags;
 316         req->ch[0] = ch[0];
 317         req->ch[1] = ch[1];
 318         req->callback = callback;
 319         req->data = data;
 320
 321         mutex_lock(&pcap->adc_mutex);
 322         if (pcap->adc_queue[pcap->adc_tail]) {
 323                 mutex_unlock(&pcap->adc_mutex);
 324                 kfree(req);
 325                 return -EBUSY;
 326         }
 327         pcap->adc_queue[pcap->adc_tail] = req;
 328         pcap->adc_tail = (pcap->adc_tail + 1) & (PCAP_ADC_MAXQ - 1);
 329         mutex_unlock(&pcap->adc_mutex);
 330
 331         /* start conversion */
 332         pcap_adc_trigger(pcap);
 333
 334         return 0;
 335 }
 336 EXPORT_SYMBOL_GPL(pcap_adc_async);
 337
 338 static void pcap_adc_sync_cb(void *param, u16 res[])
 339 {
 340         struct pcap_adc_sync_request *req = param;
 341
 342         req->res[0] = res[0];
 343         req->res[1] = res[1];
 344         complete(&req->completion);
 345 }
 346
 347 int pcap_adc_sync(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
 348                                                                 u16 res[])
 349 {
 350         struct pcap_adc_sync_request sync_data;
 351         int ret;
 352
 353         init_completion(&sync_data.completion);
 354         ret = pcap_adc_async(pcap, bank, flags, ch, pcap_adc_sync_cb,
 355                                                                 &sync_data);
 356         if (ret)
 357                 return ret;
 358         wait_for_completion(&sync_data.completion);
 359         res[0] = sync_data.res[0];
 360         res[1] = sync_data.res[1];
 361
 362         return 0;
 363 }
 364 EXPORT_SYMBOL_GPL(pcap_adc_sync);
 365
 366 /* subdevs */
 367 static int pcap_remove_subdev(struct device *dev, void *unused)
 368 {
 369         platform_device_unregister(to_platform_device(dev));
 370         return 0;
 371 }
 372
 373 static int pcap_add_subdev(struct pcap_chip *pcap,
 374                                                 struct pcap_subdev *subdev)
 375 {
 376         struct platform_device *pdev;
 377         int ret;
 378
 379         pdev = platform_device_alloc(subdev->name, subdev->id);
 380         if (!pdev)
 381                 return -ENOMEM;
 382
 383         pdev->dev.parent = &pcap->spi->dev;
 384         pdev->dev.platform_data = subdev->platform_data;
 385
 386         ret = platform_device_add(pdev);
 387         if (ret)
 388                 platform_device_put(pdev);
 389
 390         return ret;
 391 }
 392
 393 static int ezx_pcap_remove(struct spi_device *spi)
 394 {
 395         struct pcap_chip *pcap = spi_get_drvdata(spi);
 396         int i;
 397
 398         /* remove all registered subdevs */
 399         device_for_each_child(&spi->dev, NULL, pcap_remove_subdev);
 400
 401         /* cleanup ADC */
 402         mutex_lock(&pcap->adc_mutex);
 403         for (i = 0; i < PCAP_ADC_MAXQ; i++)
 404                 kfree(pcap->adc_queue[i]);
 405         mutex_unlock(&pcap->adc_mutex);
 406
 407         /* cleanup irqchip */
 408         for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++)
 409                 irq_set_chip_and_handler(i, NULL, NULL);
 410
 411         destroy_workqueue(pcap->workqueue);
 412
 413         return 0;
 414 }
 415
 416 static int ezx_pcap_probe(struct spi_device *spi)
 417 {
 418         struct pcap_platform_data *pdata = dev_get_platdata(&spi->dev);
 419         struct pcap_chip *pcap;
 420         int i, adc_irq;
 421         int ret = -ENODEV;
 422
 423         /* platform data is required */
 424         if (!pdata)
 425                 goto ret;
 426
 427         pcap = devm_kzalloc(&spi->dev, sizeof(*pcap), GFP_KERNEL);
 428         if (!pcap) {
 429                 ret = -ENOMEM;
 430                 goto ret;
 431         }
 432
 433         mutex_init(&pcap->io_mutex);
 434         mutex_init(&pcap->adc_mutex);
 435         INIT_WORK(&pcap->isr_work, pcap_isr_work);
 436         INIT_WORK(&pcap->msr_work, pcap_msr_work);
 437         spi_set_drvdata(spi, pcap);
 438
 439         /* setup spi */
 440         spi->bits_per_word = 32;
 441         spi->mode = SPI_MODE_0 | (pdata->config & PCAP_CS_AH ? SPI_CS_HIGH : 0);
 442         ret = spi_setup(spi);
 443         if (ret)
 444                 goto ret;
 445
 446         pcap->spi = spi;
 447
 448         /* setup irq */
 449         pcap->irq_base = pdata->irq_base;
 450         pcap->workqueue = create_singlethread_workqueue("pcapd");
 451         if (!pcap->workqueue) {
 452                 ret = -ENOMEM;
 453                 dev_err(&spi->dev, "can't create pcap thread\n");
 454                 goto ret;
 455         }
 456
 457         /* redirect interrupts to AP, except adcdone2 */
 458         if (!(pdata->config & PCAP_SECOND_PORT))
 459                 ezx_pcap_write(pcap, PCAP_REG_INT_SEL,
 460                                         (1 << PCAP_IRQ_ADCDONE2));
 461
 462         /* setup irq chip */
 463         for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++) {
 464                 irq_set_chip_and_handler(i, &pcap_irq_chip, handle_simple_irq);
 465                 irq_set_chip_data(i, pcap);
 466                 irq_clear_status_flags(i, IRQ_NOREQUEST | IRQ_NOPROBE);
 467         }
 468
 469         /* mask/ack all PCAP interrupts */
 470         ezx_pcap_write(pcap, PCAP_REG_MSR, PCAP_MASK_ALL_INTERRUPT);
 471         ezx_pcap_write(pcap, PCAP_REG_ISR, PCAP_CLEAR_INTERRUPT_REGISTER);
 472         pcap->msr = PCAP_MASK_ALL_INTERRUPT;
 473
 474         irq_set_irq_type(spi->irq, IRQ_TYPE_EDGE_RISING);
 475         irq_set_chained_handler_and_data(spi->irq, pcap_irq_handler, pcap);
 476         irq_set_irq_wake(spi->irq, 1);
 477
 478         /* ADC */
 479         adc_irq = pcap_to_irq(pcap, (pdata->config & PCAP_SECOND_PORT) ?
 480                                         PCAP_IRQ_ADCDONE2 : PCAP_IRQ_ADCDONE);
 481
 482         ret = devm_request_irq(&spi->dev, adc_irq, pcap_adc_irq, 0, "ADC",
 483                                 pcap);
 484         if (ret)
 485                 goto free_irqchip;
 486
 487         /* setup subdevs */
 488         for (i = 0; i < pdata->num_subdevs; i++) {
 489                 ret = pcap_add_subdev(pcap, &pdata->subdevs[i]);
 490                 if (ret)
 491                         goto remove_subdevs;
 492         }
 493
 494         /* board specific quirks */
 495         if (pdata->init)
 496                 pdata->init(pcap);
 497
 498         return 0;
 499
 500 remove_subdevs:
 501         device_for_each_child(&spi->dev, NULL, pcap_remove_subdev);
 502 free_irqchip:
 503         for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++)
 504                 irq_set_chip_and_handler(i, NULL, NULL);
 505 /* destroy_workqueue: */
 506         destroy_workqueue(pcap->workqueue);
 507 ret:
 508         return ret;
 509 }
 510
 511 static struct spi_driver ezxpcap_driver = {
 512         .probe  = ezx_pcap_probe,
 513         .remove = ezx_pcap_remove,
 514         .driver = {
 515                 .name   = "ezx-pcap",
 516         },
 517 };
 518
 519 static int __init ezx_pcap_init(void)
 520 {
 521         return spi_register_driver(&ezxpcap_driver);
 522 }
 523
 524 static void __exit ezx_pcap_exit(void)
 525 {
 526         spi_unregister_driver(&ezxpcap_driver);
 527 }
 528
 529 subsys_initcall(ezx_pcap_init);
 530 module_exit(ezx_pcap_exit);
 531
 532 MODULE_LICENSE("GPL");
 533 MODULE_AUTHOR("Daniel Ribeiro / Harald Welte");
 534 MODULE_DESCRIPTION("Motorola PCAP2 ASIC Driver");
 535 MODULE_ALIAS("spi:ezx-pcap");