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
  21 #define PCAP_ADC_MAXQ           8
  22 struct pcap_adc_request {
  23         u8 bank;
  24         u8 ch[2];
  25         u32 flags;
  26         void (*callback)(void *, u16[]);
  27         void *data;
  28 };
  29
  30 struct pcap_adc_sync_request {
  31         u16 res[2];
  32         struct completion completion;
  33 };
  34
  35 struct pcap_chip {
  36         struct spi_device *spi;
  37
  38         /* IO */
  39         u32 buf;
  40         struct mutex io_mutex;
  41
  42         /* IRQ */
  43         unsigned int irq_base;
  44         u32 msr;
  45         struct work_struct isr_work;
  46         struct work_struct msr_work;
  47         struct workqueue_struct *workqueue;
  48
  49         /* ADC */
  50         struct pcap_adc_request *adc_queue[PCAP_ADC_MAXQ];
  51         u8 adc_head;
  52         u8 adc_tail;
  53         struct mutex adc_mutex;
  54 };
  55
  56 /* IO */
  57 static int ezx_pcap_putget(struct pcap_chip *pcap, u32 *data)
  58 {
  59         struct spi_transfer t;
  60         struct spi_message m;
  61         int status;
  62
  63         memset(&t, 0, sizeof t);
  64         spi_message_init(&m);
  65         t.len = sizeof(u32);
  66         spi_message_add_tail(&t, &m);
  67
  68         pcap->buf = *data;
  69         t.tx_buf = (u8 *) &pcap->buf;
  70         t.rx_buf = (u8 *) &pcap->buf;
  71         status = spi_sync(pcap->spi, &m);
  72
  73         if (status == 0)
  74                 *data = pcap->buf;
  75
  76         return status;
  77 }
  78
  79 int ezx_pcap_write(struct pcap_chip *pcap, u8 reg_num, u32 value)
  80 {
  81         int ret;
  82
  83         mutex_lock(&pcap->io_mutex);
  84         value &= PCAP_REGISTER_VALUE_MASK;
  85         value |= PCAP_REGISTER_WRITE_OP_BIT
  86                 | (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
  87         ret = ezx_pcap_putget(pcap, &value);
  88         mutex_unlock(&pcap->io_mutex);
  89
  90         return ret;
  91 }
  92 EXPORT_SYMBOL_GPL(ezx_pcap_write);
  93
  94 int ezx_pcap_read(struct pcap_chip *pcap, u8 reg_num, u32 *value)
  95 {
  96         int ret;
  97
  98         mutex_lock(&pcap->io_mutex);
  99         *value = PCAP_REGISTER_READ_OP_BIT
 100                 | (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
 101
 102         ret = ezx_pcap_putget(pcap, value);
 103         mutex_unlock(&pcap->io_mutex);
 104
 105         return ret;
 106 }
 107 EXPORT_SYMBOL_GPL(ezx_pcap_read);
 108
 109 /* IRQ */
 110 static inline unsigned int irq2pcap(struct pcap_chip *pcap, int irq)
 111 {
 112         return 1 << (irq - pcap->irq_base);
 113 }
 114
 115 int pcap_to_irq(struct pcap_chip *pcap, int irq)
 116 {
 117         return pcap->irq_base + irq;
 118 }
 119 EXPORT_SYMBOL_GPL(pcap_to_irq);
 120
 121 static void pcap_mask_irq(unsigned int irq)
 122 {
 123         struct pcap_chip *pcap = get_irq_chip_data(irq);
 124
 125         pcap->msr |= irq2pcap(pcap, irq);
 126         queue_work(pcap->workqueue, &pcap->msr_work);
 127 }
 128
 129 static void pcap_unmask_irq(unsigned int irq)
 130 {
 131         struct pcap_chip *pcap = get_irq_chip_data(irq);
 132
 133         pcap->msr &= ~irq2pcap(pcap, irq);
 134         queue_work(pcap->workqueue, &pcap->msr_work);
 135 }
 136
 137 static struct irq_chip pcap_irq_chip = {
 138         .name   = "pcap",
 139         .mask   = pcap_mask_irq,
 140         .unmask = pcap_unmask_irq,
 141 };
 142
 143 static void pcap_msr_work(struct work_struct *work)
 144 {
 145         struct pcap_chip *pcap = container_of(work, struct pcap_chip, msr_work);
 146
 147         ezx_pcap_write(pcap, PCAP_REG_MSR, pcap->msr);
 148 }
 149
 150 static void pcap_isr_work(struct work_struct *work)
 151 {
 152         struct pcap_chip *pcap = container_of(work, struct pcap_chip, isr_work);
 153         struct pcap_platform_data *pdata = pcap->spi->dev.platform_data;
 154         u32 msr, isr, int_sel, service;
 155         int irq;
 156
 157         ezx_pcap_read(pcap, PCAP_REG_MSR, &msr);
 158         ezx_pcap_read(pcap, PCAP_REG_ISR, &isr);
 159
 160         /* We cant service/ack irqs that are assigned to port 2 */
 161         if (!(pdata->config & PCAP_SECOND_PORT)) {
 162                 ezx_pcap_read(pcap, PCAP_REG_INT_SEL, &int_sel);
 163                 isr &= ~int_sel;
 164         }
 165         ezx_pcap_write(pcap, PCAP_REG_ISR, isr);
 166
 167         local_irq_disable();
 168         service = isr & ~msr;
 169
 170         for (irq = pcap->irq_base; service; service >>= 1, irq++) {
 171                 if (service & 1) {
 172                         struct irq_desc *desc = irq_to_desc(irq);
 173
 174                         if (WARN(!desc, KERN_WARNING
 175                                         "Invalid PCAP IRQ %d\n", irq))
 176                                 break;
 177
 178                         if (desc->status & IRQ_DISABLED)
 179                                 note_interrupt(irq, desc, IRQ_NONE);
 180                         else
 181                                 desc->handle_irq(irq, desc);
 182                 }
 183         }
 184         local_irq_enable();
 185 }
 186
 187 static void pcap_irq_handler(unsigned int irq, struct irq_desc *desc)
 188 {
 189         struct pcap_chip *pcap = get_irq_data(irq);
 190
 191         desc->chip->ack(irq);
 192         queue_work(pcap->workqueue, &pcap->isr_work);
 193         return;
 194 }
 195
 196 /* ADC */
 197 static void pcap_disable_adc(struct pcap_chip *pcap)
 198 {
 199         u32 tmp;
 200
 201         ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
 202         tmp &= ~(PCAP_ADC_ADEN|PCAP_ADC_BATT_I_ADC|PCAP_ADC_BATT_I_POLARITY);
 203         ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
 204 }
 205
 206 static void pcap_adc_trigger(struct pcap_chip *pcap)
 207 {
 208         u32 tmp;
 209         u8 head;
 210
 211         mutex_lock(&pcap->adc_mutex);
 212         head = pcap->adc_head;
 213         if (!pcap->adc_queue[head]) {
 214                 /* queue is empty, save power */
 215                 pcap_disable_adc(pcap);
 216                 mutex_unlock(&pcap->adc_mutex);
 217                 return;
 218         }
 219         mutex_unlock(&pcap->adc_mutex);
 220
 221         /* start conversion on requested bank */
 222         tmp = pcap->adc_queue[head]->flags | PCAP_ADC_ADEN;
 223
 224         if (pcap->adc_queue[head]->bank == PCAP_ADC_BANK_1)
 225                 tmp |= PCAP_ADC_AD_SEL1;
 226
 227         ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
 228         ezx_pcap_write(pcap, PCAP_REG_ADR, PCAP_ADR_ASC);
 229 }
 230
 231 static irqreturn_t pcap_adc_irq(int irq, void *_pcap)
 232 {
 233         struct pcap_chip *pcap = _pcap;
 234         struct pcap_adc_request *req;
 235         u16 res[2];
 236         u32 tmp;
 237
 238         mutex_lock(&pcap->adc_mutex);
 239         req = pcap->adc_queue[pcap->adc_head];
 240
 241         if (WARN(!req, KERN_WARNING "adc irq without pending request\n"))
 242                 return IRQ_HANDLED;
 243
 244         /* read requested channels results */
 245         ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
 246         tmp &= ~(PCAP_ADC_ADA1_MASK | PCAP_ADC_ADA2_MASK);
 247         tmp |= (req->ch[0] << PCAP_ADC_ADA1_SHIFT);
 248         tmp |= (req->ch[1] << PCAP_ADC_ADA2_SHIFT);
 249         ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
 250         ezx_pcap_read(pcap, PCAP_REG_ADR, &tmp);
 251         res[0] = (tmp & PCAP_ADR_ADD1_MASK) >> PCAP_ADR_ADD1_SHIFT;
 252         res[1] = (tmp & PCAP_ADR_ADD2_MASK) >> PCAP_ADR_ADD2_SHIFT;
 253
 254         pcap->adc_queue[pcap->adc_head] = NULL;
 255         pcap->adc_head = (pcap->adc_head + 1) & (PCAP_ADC_MAXQ - 1);
 256         mutex_unlock(&pcap->adc_mutex);
 257
 258         /* pass the results and release memory */
 259         req->callback(req->data, res);
 260         kfree(req);
 261
 262         /* trigger next conversion (if any) on queue */
 263         pcap_adc_trigger(pcap);
 264
 265         return IRQ_HANDLED;
 266 }
 267
 268 int pcap_adc_async(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
 269                                                 void *callback, void *data)
 270 {
 271         struct pcap_adc_request *req;
 272
 273         /* This will be freed after we have a result */
 274         req = kmalloc(sizeof(struct pcap_adc_request), GFP_KERNEL);
 275         if (!req)
 276                 return -ENOMEM;
 277
 278         req->bank = bank;
 279         req->flags = flags;
 280         req->ch[0] = ch[0];
 281         req->ch[1] = ch[1];
 282         req->callback = callback;
 283         req->data = data;
 284
 285         mutex_lock(&pcap->adc_mutex);
 286         if (pcap->adc_queue[pcap->adc_tail]) {
 287                 mutex_unlock(&pcap->adc_mutex);
 288                 kfree(req);
 289                 return -EBUSY;
 290         }
 291         pcap->adc_queue[pcap->adc_tail] = req;
 292         pcap->adc_tail = (pcap->adc_tail + 1) & (PCAP_ADC_MAXQ - 1);
 293         mutex_unlock(&pcap->adc_mutex);
 294
 295         /* start conversion */
 296         pcap_adc_trigger(pcap);
 297
 298         return 0;
 299 }
 300 EXPORT_SYMBOL_GPL(pcap_adc_async);
 301
 302 static void pcap_adc_sync_cb(void *param, u16 res[])
 303 {
 304         struct pcap_adc_sync_request *req = param;
 305
 306         req->res[0] = res[0];
 307         req->res[1] = res[1];
 308         complete(&req->completion);
 309 }
 310
 311 int pcap_adc_sync(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
 312                                                                 u16 res[])
 313 {
 314         struct pcap_adc_sync_request sync_data;
 315         int ret;
 316
 317         init_completion(&sync_data.completion);
 318         ret = pcap_adc_async(pcap, bank, flags, ch, pcap_adc_sync_cb,
 319                                                                 &sync_data);
 320         if (ret)
 321                 return ret;
 322         wait_for_completion(&sync_data.completion);
 323         res[0] = sync_data.res[0];
 324         res[1] = sync_data.res[1];
 325
 326         return 0;
 327 }
 328 EXPORT_SYMBOL_GPL(pcap_adc_sync);
 329
 330 /* subdevs */
 331 static int pcap_remove_subdev(struct device *dev, void *unused)
 332 {
 333         platform_device_unregister(to_platform_device(dev));
 334         return 0;
 335 }
 336
 337 static int __devinit pcap_add_subdev(struct pcap_chip *pcap,
 338                                                 struct pcap_subdev *subdev)
 339 {
 340         struct platform_device *pdev;
 341
 342         pdev = platform_device_alloc(subdev->name, subdev->id);
 343         pdev->dev.parent = &pcap->spi->dev;
 344         pdev->dev.platform_data = subdev->platform_data;
 345         platform_set_drvdata(pdev, pcap);
 346
 347         return platform_device_add(pdev);
 348 }
 349
 350 static int __devexit ezx_pcap_remove(struct spi_device *spi)
 351 {
 352         struct pcap_chip *pcap = dev_get_drvdata(&spi->dev);
 353         struct pcap_platform_data *pdata = spi->dev.platform_data;
 354         int i, adc_irq;
 355
 356         /* remove all registered subdevs */
 357         device_for_each_child(&spi->dev, NULL, pcap_remove_subdev);
 358
 359         /* cleanup ADC */
 360         adc_irq = pcap_to_irq(pcap, (pdata->config & PCAP_SECOND_PORT) ?
 361                                 PCAP_IRQ_ADCDONE2 : PCAP_IRQ_ADCDONE);
 362         free_irq(adc_irq, pcap);
 363         mutex_lock(&pcap->adc_mutex);
 364         for (i = 0; i < PCAP_ADC_MAXQ; i++)
 365                 kfree(pcap->adc_queue[i]);
 366         mutex_unlock(&pcap->adc_mutex);
 367
 368         /* cleanup irqchip */
 369         for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++)
 370                 set_irq_chip_and_handler(i, NULL, NULL);
 371
 372         destroy_workqueue(pcap->workqueue);
 373
 374         kfree(pcap);
 375
 376         return 0;
 377 }
 378
 379 static int __devinit ezx_pcap_probe(struct spi_device *spi)
 380 {
 381         struct pcap_platform_data *pdata = spi->dev.platform_data;
 382         struct pcap_chip *pcap;
 383         int i, adc_irq;
 384         int ret = -ENODEV;
 385
 386         /* platform data is required */
 387         if (!pdata)
 388                 goto ret;
 389
 390         pcap = kzalloc(sizeof(*pcap), GFP_KERNEL);
 391         if (!pcap) {
 392                 ret = -ENOMEM;
 393                 goto ret;
 394         }
 395
 396         mutex_init(&pcap->io_mutex);
 397         mutex_init(&pcap->adc_mutex);
 398         INIT_WORK(&pcap->isr_work, pcap_isr_work);
 399         INIT_WORK(&pcap->msr_work, pcap_msr_work);
 400         dev_set_drvdata(&spi->dev, pcap);
 401
 402         /* setup spi */
 403         spi->bits_per_word = 32;
 404         spi->mode = SPI_MODE_0 | (pdata->config & PCAP_CS_AH ? SPI_CS_HIGH : 0);
 405         ret = spi_setup(spi);
 406         if (ret)
 407                 goto free_pcap;
 408
 409         pcap->spi = spi;
 410
 411         /* setup irq */
 412         pcap->irq_base = pdata->irq_base;
 413         pcap->workqueue = create_singlethread_workqueue("pcapd");
 414         if (!pcap->workqueue) {
 415                 dev_err(&spi->dev, "cant create pcap thread\n");
 416                 goto free_pcap;
 417         }
 418
 419         /* redirect interrupts to AP, except adcdone2 */
 420         if (!(pdata->config & PCAP_SECOND_PORT))
 421                 ezx_pcap_write(pcap, PCAP_REG_INT_SEL,
 422                                         (1 << PCAP_IRQ_ADCDONE2));
 423
 424         /* setup irq chip */
 425         for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++) {
 426                 set_irq_chip_and_handler(i, &pcap_irq_chip, handle_simple_irq);
 427                 set_irq_chip_data(i, pcap);
 428 #ifdef CONFIG_ARM
 429                 set_irq_flags(i, IRQF_VALID);
 430 #else
 431                 set_irq_noprobe(i);
 432 #endif
 433         }
 434
 435         /* mask/ack all PCAP interrupts */
 436         ezx_pcap_write(pcap, PCAP_REG_MSR, PCAP_MASK_ALL_INTERRUPT);
 437         ezx_pcap_write(pcap, PCAP_REG_ISR, PCAP_CLEAR_INTERRUPT_REGISTER);
 438         pcap->msr = PCAP_MASK_ALL_INTERRUPT;
 439
 440         set_irq_type(spi->irq, IRQ_TYPE_EDGE_RISING);
 441         set_irq_data(spi->irq, pcap);
 442         set_irq_chained_handler(spi->irq, pcap_irq_handler);
 443         set_irq_wake(spi->irq, 1);
 444
 445         /* ADC */
 446         adc_irq = pcap_to_irq(pcap, (pdata->config & PCAP_SECOND_PORT) ?
 447                                         PCAP_IRQ_ADCDONE2 : PCAP_IRQ_ADCDONE);
 448
 449         ret = request_irq(adc_irq, pcap_adc_irq, 0, "ADC", pcap);
 450         if (ret)
 451                 goto free_irqchip;
 452
 453         /* setup subdevs */
 454         for (i = 0; i < pdata->num_subdevs; i++) {
 455                 ret = pcap_add_subdev(pcap, &pdata->subdevs[i]);
 456                 if (ret)
 457                         goto remove_subdevs;
 458         }
 459
 460         /* board specific quirks */
 461         if (pdata->init)
 462                 pdata->init(pcap);
 463
 464         return 0;
 465
 466 remove_subdevs:
 467         device_for_each_child(&spi->dev, NULL, pcap_remove_subdev);
 468 /* free_adc: */
 469         free_irq(adc_irq, pcap);
 470 free_irqchip:
 471         for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++)
 472                 set_irq_chip_and_handler(i, NULL, NULL);
 473 /* destroy_workqueue: */
 474         destroy_workqueue(pcap->workqueue);
 475 free_pcap:
 476         kfree(pcap);
 477 ret:
 478         return ret;
 479 }
 480
 481 static struct spi_driver ezxpcap_driver = {
 482         .probe  = ezx_pcap_probe,
 483         .remove = __devexit_p(ezx_pcap_remove),
 484         .driver = {
 485                 .name   = "ezx-pcap",
 486                 .owner  = THIS_MODULE,
 487         },
 488 };
 489
 490 static int __init ezx_pcap_init(void)
 491 {
 492         return spi_register_driver(&ezxpcap_driver);
 493 }
 494
 495 static void __exit ezx_pcap_exit(void)
 496 {
 497         spi_unregister_driver(&ezxpcap_driver);
 498 }
 499
 500 module_init(ezx_pcap_init);
 501 module_exit(ezx_pcap_exit);
 502
 503 MODULE_LICENSE("GPL");
 504 MODULE_AUTHOR("Daniel Ribeiro / Harald Welte");
 505 MODULE_DESCRIPTION("Motorola PCAP2 ASIC Driver");