linux/drivers/mfd/ezx-pcap.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Driver for Motorola PCAP2 as present in EZX phones
   4 *
   5 * Copyright (C) 2006 Harald Welte <laforge@openezx.org>
   6 * Copyright (C) 2009 Daniel Ribeiro <drwyrm@gmail.com>
   7 */
   8
   9#include <linux/module.h>
  10#include <linux/kernel.h>
  11#include <linux/platform_device.h>
  12#include <linux/interrupt.h>
  13#include <linux/irq.h>
  14#include <linux/mfd/ezx-pcap.h>
  15#include <linux/spi/spi.h>
  16#include <linux/gpio.h>
  17#include <linux/slab.h>
  18
  19#define PCAP_ADC_MAXQ           8
  20struct pcap_adc_request {
  21        u8 bank;
  22        u8 ch[2];
  23        u32 flags;
  24        void (*callback)(void *, u16[]);
  25        void *data;
  26};
  27
  28struct pcap_adc_sync_request {
  29        u16 res[2];
  30        struct completion completion;
  31};
  32
  33struct pcap_chip {
  34        struct spi_device *spi;
  35
  36        /* IO */
  37        u32 buf;
  38        spinlock_t io_lock;
  39
  40        /* IRQ */
  41        unsigned int irq_base;
  42        u32 msr;
  43        struct work_struct isr_work;
  44        struct work_struct msr_work;
  45        struct workqueue_struct *workqueue;
  46
  47        /* ADC */
  48        struct pcap_adc_request *adc_queue[PCAP_ADC_MAXQ];
  49        u8 adc_head;
  50        u8 adc_tail;
  51        spinlock_t adc_lock;
  52};
  53
  54/* IO */
  55static int ezx_pcap_putget(struct pcap_chip *pcap, u32 *data)
  56{
  57        struct spi_transfer t;
  58        struct spi_message m;
  59        int status;
  60
  61        memset(&t, 0, sizeof(t));
  62        spi_message_init(&m);
  63        t.len = sizeof(u32);
  64        spi_message_add_tail(&t, &m);
  65
  66        pcap->buf = *data;
  67        t.tx_buf = (u8 *) &pcap->buf;
  68        t.rx_buf = (u8 *) &pcap->buf;
  69        status = spi_sync(pcap->spi, &m);
  70
  71        if (status == 0)
  72                *data = pcap->buf;
  73
  74        return status;
  75}
  76
  77int ezx_pcap_write(struct pcap_chip *pcap, u8 reg_num, u32 value)
  78{
  79        unsigned long flags;
  80        int ret;
  81
  82        spin_lock_irqsave(&pcap->io_lock, flags);
  83        value &= PCAP_REGISTER_VALUE_MASK;
  84        value |= PCAP_REGISTER_WRITE_OP_BIT
  85                | (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
  86        ret = ezx_pcap_putget(pcap, &value);
  87        spin_unlock_irqrestore(&pcap->io_lock, flags);
  88
  89        return ret;
  90}
  91EXPORT_SYMBOL_GPL(ezx_pcap_write);
  92
  93int ezx_pcap_read(struct pcap_chip *pcap, u8 reg_num, u32 *value)
  94{
  95        unsigned long flags;
  96        int ret;
  97
  98        spin_lock_irqsave(&pcap->io_lock, flags);
  99        *value = PCAP_REGISTER_READ_OP_BIT
 100                | (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
 101
 102        ret = ezx_pcap_putget(pcap, value);
 103        spin_unlock_irqrestore(&pcap->io_lock, flags);
 104
 105        return ret;
 106}
 107EXPORT_SYMBOL_GPL(ezx_pcap_read);
 108
 109int ezx_pcap_set_bits(struct pcap_chip *pcap, u8 reg_num, u32 mask, u32 val)
 110{
 111        unsigned long flags;
 112        int ret;
 113        u32 tmp = PCAP_REGISTER_READ_OP_BIT |
 114                (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
 115
 116        spin_lock_irqsave(&pcap->io_lock, flags);
 117        ret = ezx_pcap_putget(pcap, &tmp);
 118        if (ret)
 119                goto out_unlock;
 120
 121        tmp &= (PCAP_REGISTER_VALUE_MASK & ~mask);
 122        tmp |= (val & mask) | PCAP_REGISTER_WRITE_OP_BIT |
 123                (reg_num << PCAP_REGISTER_ADDRESS_SHIFT);
 124
 125        ret = ezx_pcap_putget(pcap, &tmp);
 126out_unlock:
 127        spin_unlock_irqrestore(&pcap->io_lock, flags);
 128
 129        return ret;
 130}
 131EXPORT_SYMBOL_GPL(ezx_pcap_set_bits);
 132
 133/* IRQ */
 134int irq_to_pcap(struct pcap_chip *pcap, int irq)
 135{
 136        return irq - pcap->irq_base;
 137}
 138EXPORT_SYMBOL_GPL(irq_to_pcap);
 139
 140int pcap_to_irq(struct pcap_chip *pcap, int irq)
 141{
 142        return pcap->irq_base + irq;
 143}
 144EXPORT_SYMBOL_GPL(pcap_to_irq);
 145
 146static void pcap_mask_irq(struct irq_data *d)
 147{
 148        struct pcap_chip *pcap = irq_data_get_irq_chip_data(d);
 149
 150        pcap->msr |= 1 << irq_to_pcap(pcap, d->irq);
 151        queue_work(pcap->workqueue, &pcap->msr_work);
 152}
 153
 154static void pcap_unmask_irq(struct irq_data *d)
 155{
 156        struct pcap_chip *pcap = irq_data_get_irq_chip_data(d);
 157
 158        pcap->msr &= ~(1 << irq_to_pcap(pcap, d->irq));
 159        queue_work(pcap->workqueue, &pcap->msr_work);
 160}
 161
 162static struct irq_chip pcap_irq_chip = {
 163        .name           = "pcap",
 164        .irq_disable    = pcap_mask_irq,
 165        .irq_mask       = pcap_mask_irq,
 166        .irq_unmask     = pcap_unmask_irq,
 167};
 168
 169static 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
 176static 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 = dev_get_platdata(&pcap->spi->dev);
 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 can't 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                                generic_handle_irq(irq);
 201                }
 202                local_irq_enable();
 203                ezx_pcap_write(pcap, PCAP_REG_MSR, pcap->msr);
 204        } while (gpio_get_value(pdata->gpio));
 205}
 206
 207static void pcap_irq_handler(struct irq_desc *desc)
 208{
 209        struct pcap_chip *pcap = irq_desc_get_handler_data(desc);
 210
 211        desc->irq_data.chip->irq_ack(&desc->irq_data);
 212        queue_work(pcap->workqueue, &pcap->isr_work);
 213}
 214
 215/* ADC */
 216void pcap_set_ts_bits(struct pcap_chip *pcap, u32 bits)
 217{
 218        unsigned long flags;
 219        u32 tmp;
 220
 221        spin_lock_irqsave(&pcap->adc_lock, flags);
 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        spin_unlock_irqrestore(&pcap->adc_lock, flags);
 227}
 228EXPORT_SYMBOL_GPL(pcap_set_ts_bits);
 229
 230static 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
 239static void pcap_adc_trigger(struct pcap_chip *pcap)
 240{
 241        unsigned long flags;
 242        u32 tmp;
 243        u8 head;
 244
 245        spin_lock_irqsave(&pcap->adc_lock, flags);
 246        head = pcap->adc_head;
 247        if (!pcap->adc_queue[head]) {
 248                /* queue is empty, save power */
 249                pcap_disable_adc(pcap);
 250                spin_unlock_irqrestore(&pcap->adc_lock, flags);
 251                return;
 252        }
 253        /* start conversion on requested bank, save TS_M bits */
 254        ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
 255        tmp &= (PCAP_ADC_TS_M_MASK | PCAP_ADC_TS_REF_LOWPWR);
 256        tmp |= pcap->adc_queue[head]->flags | PCAP_ADC_ADEN;
 257
 258        if (pcap->adc_queue[head]->bank == PCAP_ADC_BANK_1)
 259                tmp |= PCAP_ADC_AD_SEL1;
 260
 261        ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
 262        spin_unlock_irqrestore(&pcap->adc_lock, flags);
 263        ezx_pcap_write(pcap, PCAP_REG_ADR, PCAP_ADR_ASC);
 264}
 265
 266static irqreturn_t pcap_adc_irq(int irq, void *_pcap)
 267{
 268        struct pcap_chip *pcap = _pcap;
 269        struct pcap_adc_request *req;
 270        u16 res[2];
 271        u32 tmp;
 272
 273        spin_lock(&pcap->adc_lock);
 274        req = pcap->adc_queue[pcap->adc_head];
 275
 276        if (WARN(!req, "adc irq without pending request\n")) {
 277                spin_unlock(&pcap->adc_lock);
 278                return IRQ_HANDLED;
 279        }
 280
 281        /* read requested channels results */
 282        ezx_pcap_read(pcap, PCAP_REG_ADC, &tmp);
 283        tmp &= ~(PCAP_ADC_ADA1_MASK | PCAP_ADC_ADA2_MASK);
 284        tmp |= (req->ch[0] << PCAP_ADC_ADA1_SHIFT);
 285        tmp |= (req->ch[1] << PCAP_ADC_ADA2_SHIFT);
 286        ezx_pcap_write(pcap, PCAP_REG_ADC, tmp);
 287        ezx_pcap_read(pcap, PCAP_REG_ADR, &tmp);
 288        res[0] = (tmp & PCAP_ADR_ADD1_MASK) >> PCAP_ADR_ADD1_SHIFT;
 289        res[1] = (tmp & PCAP_ADR_ADD2_MASK) >> PCAP_ADR_ADD2_SHIFT;
 290
 291        pcap->adc_queue[pcap->adc_head] = NULL;
 292        pcap->adc_head = (pcap->adc_head + 1) & (PCAP_ADC_MAXQ - 1);
 293        spin_unlock(&pcap->adc_lock);
 294
 295        /* pass the results and release memory */
 296        req->callback(req->data, res);
 297        kfree(req);
 298
 299        /* trigger next conversion (if any) on queue */
 300        pcap_adc_trigger(pcap);
 301
 302        return IRQ_HANDLED;
 303}
 304
 305int pcap_adc_async(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
 306                                                void *callback, void *data)
 307{
 308        struct pcap_adc_request *req;
 309        unsigned long irq_flags;
 310
 311        /* This will be freed after we have a result */
 312        req = kmalloc(sizeof(struct pcap_adc_request), GFP_KERNEL);
 313        if (!req)
 314                return -ENOMEM;
 315
 316        req->bank = bank;
 317        req->flags = flags;
 318        req->ch[0] = ch[0];
 319        req->ch[1] = ch[1];
 320        req->callback = callback;
 321        req->data = data;
 322
 323        spin_lock_irqsave(&pcap->adc_lock, irq_flags);
 324        if (pcap->adc_queue[pcap->adc_tail]) {
 325                spin_unlock_irqrestore(&pcap->adc_lock, irq_flags);
 326                kfree(req);
 327                return -EBUSY;
 328        }
 329        pcap->adc_queue[pcap->adc_tail] = req;
 330        pcap->adc_tail = (pcap->adc_tail + 1) & (PCAP_ADC_MAXQ - 1);
 331        spin_unlock_irqrestore(&pcap->adc_lock, irq_flags);
 332
 333        /* start conversion */
 334        pcap_adc_trigger(pcap);
 335
 336        return 0;
 337}
 338EXPORT_SYMBOL_GPL(pcap_adc_async);
 339
 340static void pcap_adc_sync_cb(void *param, u16 res[])
 341{
 342        struct pcap_adc_sync_request *req = param;
 343
 344        req->res[0] = res[0];
 345        req->res[1] = res[1];
 346        complete(&req->completion);
 347}
 348
 349int pcap_adc_sync(struct pcap_chip *pcap, u8 bank, u32 flags, u8 ch[],
 350                                                                u16 res[])
 351{
 352        struct pcap_adc_sync_request sync_data;
 353        int ret;
 354
 355        init_completion(&sync_data.completion);
 356        ret = pcap_adc_async(pcap, bank, flags, ch, pcap_adc_sync_cb,
 357                                                                &sync_data);
 358        if (ret)
 359                return ret;
 360        wait_for_completion(&sync_data.completion);
 361        res[0] = sync_data.res[0];
 362        res[1] = sync_data.res[1];
 363
 364        return 0;
 365}
 366EXPORT_SYMBOL_GPL(pcap_adc_sync);
 367
 368/* subdevs */
 369static int pcap_remove_subdev(struct device *dev, void *unused)
 370{
 371        platform_device_unregister(to_platform_device(dev));
 372        return 0;
 373}
 374
 375static int pcap_add_subdev(struct pcap_chip *pcap,
 376                                                struct pcap_subdev *subdev)
 377{
 378        struct platform_device *pdev;
 379        int ret;
 380
 381        pdev = platform_device_alloc(subdev->name, subdev->id);
 382        if (!pdev)
 383                return -ENOMEM;
 384
 385        pdev->dev.parent = &pcap->spi->dev;
 386        pdev->dev.platform_data = subdev->platform_data;
 387
 388        ret = platform_device_add(pdev);
 389        if (ret)
 390                platform_device_put(pdev);
 391
 392        return ret;
 393}
 394
 395static int ezx_pcap_remove(struct spi_device *spi)
 396{
 397        struct pcap_chip *pcap = spi_get_drvdata(spi);
 398        unsigned long flags;
 399        int i;
 400
 401        /* remove all registered subdevs */
 402        device_for_each_child(&spi->dev, NULL, pcap_remove_subdev);
 403
 404        /* cleanup ADC */
 405        spin_lock_irqsave(&pcap->adc_lock, flags);
 406        for (i = 0; i < PCAP_ADC_MAXQ; i++)
 407                kfree(pcap->adc_queue[i]);
 408        spin_unlock_irqrestore(&pcap->adc_lock, flags);
 409
 410        /* cleanup irqchip */
 411        for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++)
 412                irq_set_chip_and_handler(i, NULL, NULL);
 413
 414        destroy_workqueue(pcap->workqueue);
 415
 416        return 0;
 417}
 418
 419static int ezx_pcap_probe(struct spi_device *spi)
 420{
 421        struct pcap_platform_data *pdata = dev_get_platdata(&spi->dev);
 422        struct pcap_chip *pcap;
 423        int i, adc_irq;
 424        int ret = -ENODEV;
 425
 426        /* platform data is required */
 427        if (!pdata)
 428                goto ret;
 429
 430        pcap = devm_kzalloc(&spi->dev, sizeof(*pcap), GFP_KERNEL);
 431        if (!pcap) {
 432                ret = -ENOMEM;
 433                goto ret;
 434        }
 435
 436        spin_lock_init(&pcap->io_lock);
 437        spin_lock_init(&pcap->adc_lock);
 438        INIT_WORK(&pcap->isr_work, pcap_isr_work);
 439        INIT_WORK(&pcap->msr_work, pcap_msr_work);
 440        spi_set_drvdata(spi, pcap);
 441
 442        /* setup spi */
 443        spi->bits_per_word = 32;
 444        spi->mode = SPI_MODE_0 | (pdata->config & PCAP_CS_AH ? SPI_CS_HIGH : 0);
 445        ret = spi_setup(spi);
 446        if (ret)
 447                goto ret;
 448
 449        pcap->spi = spi;
 450
 451        /* setup irq */
 452        pcap->irq_base = pdata->irq_base;
 453        pcap->workqueue = create_singlethread_workqueue("pcapd");
 454        if (!pcap->workqueue) {
 455                ret = -ENOMEM;
 456                dev_err(&spi->dev, "can't create pcap thread\n");
 457                goto ret;
 458        }
 459
 460        /* redirect interrupts to AP, except adcdone2 */
 461        if (!(pdata->config & PCAP_SECOND_PORT))
 462                ezx_pcap_write(pcap, PCAP_REG_INT_SEL,
 463                                        (1 << PCAP_IRQ_ADCDONE2));
 464
 465        /* setup irq chip */
 466        for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++) {
 467                irq_set_chip_and_handler(i, &pcap_irq_chip, handle_simple_irq);
 468                irq_set_chip_data(i, pcap);
 469                irq_clear_status_flags(i, IRQ_NOREQUEST | IRQ_NOPROBE);
 470        }
 471
 472        /* mask/ack all PCAP interrupts */
 473        ezx_pcap_write(pcap, PCAP_REG_MSR, PCAP_MASK_ALL_INTERRUPT);
 474        ezx_pcap_write(pcap, PCAP_REG_ISR, PCAP_CLEAR_INTERRUPT_REGISTER);
 475        pcap->msr = PCAP_MASK_ALL_INTERRUPT;
 476
 477        irq_set_irq_type(spi->irq, IRQ_TYPE_EDGE_RISING);
 478        irq_set_chained_handler_and_data(spi->irq, pcap_irq_handler, pcap);
 479        irq_set_irq_wake(spi->irq, 1);
 480
 481        /* ADC */
 482        adc_irq = pcap_to_irq(pcap, (pdata->config & PCAP_SECOND_PORT) ?
 483                                        PCAP_IRQ_ADCDONE2 : PCAP_IRQ_ADCDONE);
 484
 485        ret = devm_request_irq(&spi->dev, adc_irq, pcap_adc_irq, 0, "ADC",
 486                                pcap);
 487        if (ret)
 488                goto free_irqchip;
 489
 490        /* setup subdevs */
 491        for (i = 0; i < pdata->num_subdevs; i++) {
 492                ret = pcap_add_subdev(pcap, &pdata->subdevs[i]);
 493                if (ret)
 494                        goto remove_subdevs;
 495        }
 496
 497        /* board specific quirks */
 498        if (pdata->init)
 499                pdata->init(pcap);
 500
 501        return 0;
 502
 503remove_subdevs:
 504        device_for_each_child(&spi->dev, NULL, pcap_remove_subdev);
 505free_irqchip:
 506        for (i = pcap->irq_base; i < (pcap->irq_base + PCAP_NIRQS); i++)
 507                irq_set_chip_and_handler(i, NULL, NULL);
 508/* destroy_workqueue: */
 509        destroy_workqueue(pcap->workqueue);
 510ret:
 511        return ret;
 512}
 513
 514static struct spi_driver ezxpcap_driver = {
 515        .probe  = ezx_pcap_probe,
 516        .remove = ezx_pcap_remove,
 517        .driver = {
 518                .name   = "ezx-pcap",
 519        },
 520};
 521
 522static int __init ezx_pcap_init(void)
 523{
 524        return spi_register_driver(&ezxpcap_driver);
 525}
 526
 527static void __exit ezx_pcap_exit(void)
 528{
 529        spi_unregister_driver(&ezxpcap_driver);
 530}
 531
 532subsys_initcall(ezx_pcap_init);
 533module_exit(ezx_pcap_exit);
 534
 535MODULE_LICENSE("GPL");
 536MODULE_AUTHOR("Daniel Ribeiro / Harald Welte");
 537MODULE_DESCRIPTION("Motorola PCAP2 ASIC Driver");
 538MODULE_ALIAS("spi:ezx-pcap");
 539