linux/drivers/iio/adc/xilinx-xadc-core.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Xilinx XADC driver
   4 *
   5 * Copyright 2013-2014 Analog Devices Inc.
   6 *  Author: Lars-Peter Clausen <lars@metafoo.de>
   7 *
   8 * Documentation for the parts can be found at:
   9 *  - XADC hardmacro: Xilinx UG480
  10 *  - ZYNQ XADC interface: Xilinx UG585
  11 *  - AXI XADC interface: Xilinx PG019
  12 */
  13
  14#include <linux/clk.h>
  15#include <linux/device.h>
  16#include <linux/err.h>
  17#include <linux/interrupt.h>
  18#include <linux/io.h>
  19#include <linux/kernel.h>
  20#include <linux/module.h>
  21#include <linux/of.h>
  22#include <linux/platform_device.h>
  23#include <linux/slab.h>
  24#include <linux/sysfs.h>
  25
  26#include <linux/iio/buffer.h>
  27#include <linux/iio/events.h>
  28#include <linux/iio/iio.h>
  29#include <linux/iio/sysfs.h>
  30#include <linux/iio/trigger.h>
  31#include <linux/iio/trigger_consumer.h>
  32#include <linux/iio/triggered_buffer.h>
  33
  34#include "xilinx-xadc.h"
  35
  36static const unsigned int XADC_ZYNQ_UNMASK_TIMEOUT = 500;
  37
  38/* ZYNQ register definitions */
  39#define XADC_ZYNQ_REG_CFG       0x00
  40#define XADC_ZYNQ_REG_INTSTS    0x04
  41#define XADC_ZYNQ_REG_INTMSK    0x08
  42#define XADC_ZYNQ_REG_STATUS    0x0c
  43#define XADC_ZYNQ_REG_CFIFO     0x10
  44#define XADC_ZYNQ_REG_DFIFO     0x14
  45#define XADC_ZYNQ_REG_CTL               0x18
  46
  47#define XADC_ZYNQ_CFG_ENABLE            BIT(31)
  48#define XADC_ZYNQ_CFG_CFIFOTH_MASK      (0xf << 20)
  49#define XADC_ZYNQ_CFG_CFIFOTH_OFFSET    20
  50#define XADC_ZYNQ_CFG_DFIFOTH_MASK      (0xf << 16)
  51#define XADC_ZYNQ_CFG_DFIFOTH_OFFSET    16
  52#define XADC_ZYNQ_CFG_WEDGE             BIT(13)
  53#define XADC_ZYNQ_CFG_REDGE             BIT(12)
  54#define XADC_ZYNQ_CFG_TCKRATE_MASK      (0x3 << 8)
  55#define XADC_ZYNQ_CFG_TCKRATE_DIV2      (0x0 << 8)
  56#define XADC_ZYNQ_CFG_TCKRATE_DIV4      (0x1 << 8)
  57#define XADC_ZYNQ_CFG_TCKRATE_DIV8      (0x2 << 8)
  58#define XADC_ZYNQ_CFG_TCKRATE_DIV16     (0x3 << 8)
  59#define XADC_ZYNQ_CFG_IGAP_MASK         0x1f
  60#define XADC_ZYNQ_CFG_IGAP(x)           (x)
  61
  62#define XADC_ZYNQ_INT_CFIFO_LTH         BIT(9)
  63#define XADC_ZYNQ_INT_DFIFO_GTH         BIT(8)
  64#define XADC_ZYNQ_INT_ALARM_MASK        0xff
  65#define XADC_ZYNQ_INT_ALARM_OFFSET      0
  66
  67#define XADC_ZYNQ_STATUS_CFIFO_LVL_MASK (0xf << 16)
  68#define XADC_ZYNQ_STATUS_CFIFO_LVL_OFFSET       16
  69#define XADC_ZYNQ_STATUS_DFIFO_LVL_MASK (0xf << 12)
  70#define XADC_ZYNQ_STATUS_DFIFO_LVL_OFFSET       12
  71#define XADC_ZYNQ_STATUS_CFIFOF         BIT(11)
  72#define XADC_ZYNQ_STATUS_CFIFOE         BIT(10)
  73#define XADC_ZYNQ_STATUS_DFIFOF         BIT(9)
  74#define XADC_ZYNQ_STATUS_DFIFOE         BIT(8)
  75#define XADC_ZYNQ_STATUS_OT             BIT(7)
  76#define XADC_ZYNQ_STATUS_ALM(x)         BIT(x)
  77
  78#define XADC_ZYNQ_CTL_RESET             BIT(4)
  79
  80#define XADC_ZYNQ_CMD_NOP               0x00
  81#define XADC_ZYNQ_CMD_READ              0x01
  82#define XADC_ZYNQ_CMD_WRITE             0x02
  83
  84#define XADC_ZYNQ_CMD(cmd, addr, data) (((cmd) << 26) | ((addr) << 16) | (data))
  85
  86/* AXI register definitions */
  87#define XADC_AXI_REG_RESET              0x00
  88#define XADC_AXI_REG_STATUS             0x04
  89#define XADC_AXI_REG_ALARM_STATUS       0x08
  90#define XADC_AXI_REG_CONVST             0x0c
  91#define XADC_AXI_REG_XADC_RESET         0x10
  92#define XADC_AXI_REG_GIER               0x5c
  93#define XADC_AXI_REG_IPISR              0x60
  94#define XADC_AXI_REG_IPIER              0x68
  95#define XADC_AXI_ADC_REG_OFFSET         0x200
  96
  97#define XADC_AXI_RESET_MAGIC            0xa
  98#define XADC_AXI_GIER_ENABLE            BIT(31)
  99
 100#define XADC_AXI_INT_EOS                BIT(4)
 101#define XADC_AXI_INT_ALARM_MASK         0x3c0f
 102
 103#define XADC_FLAGS_BUFFERED BIT(0)
 104
 105/*
 106 * The XADC hardware supports a samplerate of up to 1MSPS. Unfortunately it does
 107 * not have a hardware FIFO. Which means an interrupt is generated for each
 108 * conversion sequence. At 1MSPS sample rate the CPU in ZYNQ7000 is completely
 109 * overloaded by the interrupts that it soft-lockups. For this reason the driver
 110 * limits the maximum samplerate 150kSPS. At this rate the CPU is fairly busy,
 111 * but still responsive.
 112 */
 113#define XADC_MAX_SAMPLERATE 150000
 114
 115static void xadc_write_reg(struct xadc *xadc, unsigned int reg,
 116        uint32_t val)
 117{
 118        writel(val, xadc->base + reg);
 119}
 120
 121static void xadc_read_reg(struct xadc *xadc, unsigned int reg,
 122        uint32_t *val)
 123{
 124        *val = readl(xadc->base + reg);
 125}
 126
 127/*
 128 * The ZYNQ interface uses two asynchronous FIFOs for communication with the
 129 * XADC. Reads and writes to the XADC register are performed by submitting a
 130 * request to the command FIFO (CFIFO), once the request has been completed the
 131 * result can be read from the data FIFO (DFIFO). The method currently used in
 132 * this driver is to submit the request for a read/write operation, then go to
 133 * sleep and wait for an interrupt that signals that a response is available in
 134 * the data FIFO.
 135 */
 136
 137static void xadc_zynq_write_fifo(struct xadc *xadc, uint32_t *cmd,
 138        unsigned int n)
 139{
 140        unsigned int i;
 141
 142        for (i = 0; i < n; i++)
 143                xadc_write_reg(xadc, XADC_ZYNQ_REG_CFIFO, cmd[i]);
 144}
 145
 146static void xadc_zynq_drain_fifo(struct xadc *xadc)
 147{
 148        uint32_t status, tmp;
 149
 150        xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &status);
 151
 152        while (!(status & XADC_ZYNQ_STATUS_DFIFOE)) {
 153                xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &tmp);
 154                xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &status);
 155        }
 156}
 157
 158static void xadc_zynq_update_intmsk(struct xadc *xadc, unsigned int mask,
 159        unsigned int val)
 160{
 161        xadc->zynq_intmask &= ~mask;
 162        xadc->zynq_intmask |= val;
 163
 164        xadc_write_reg(xadc, XADC_ZYNQ_REG_INTMSK,
 165                xadc->zynq_intmask | xadc->zynq_masked_alarm);
 166}
 167
 168static int xadc_zynq_write_adc_reg(struct xadc *xadc, unsigned int reg,
 169        uint16_t val)
 170{
 171        uint32_t cmd[1];
 172        uint32_t tmp;
 173        int ret;
 174
 175        spin_lock_irq(&xadc->lock);
 176        xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH,
 177                        XADC_ZYNQ_INT_DFIFO_GTH);
 178
 179        reinit_completion(&xadc->completion);
 180
 181        cmd[0] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_WRITE, reg, val);
 182        xadc_zynq_write_fifo(xadc, cmd, ARRAY_SIZE(cmd));
 183        xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &tmp);
 184        tmp &= ~XADC_ZYNQ_CFG_DFIFOTH_MASK;
 185        tmp |= 0 << XADC_ZYNQ_CFG_DFIFOTH_OFFSET;
 186        xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, tmp);
 187
 188        xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH, 0);
 189        spin_unlock_irq(&xadc->lock);
 190
 191        ret = wait_for_completion_interruptible_timeout(&xadc->completion, HZ);
 192        if (ret == 0)
 193                ret = -EIO;
 194        else
 195                ret = 0;
 196
 197        xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &tmp);
 198
 199        return ret;
 200}
 201
 202static int xadc_zynq_read_adc_reg(struct xadc *xadc, unsigned int reg,
 203        uint16_t *val)
 204{
 205        uint32_t cmd[2];
 206        uint32_t resp, tmp;
 207        int ret;
 208
 209        cmd[0] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_READ, reg, 0);
 210        cmd[1] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_NOP, 0, 0);
 211
 212        spin_lock_irq(&xadc->lock);
 213        xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH,
 214                        XADC_ZYNQ_INT_DFIFO_GTH);
 215        xadc_zynq_drain_fifo(xadc);
 216        reinit_completion(&xadc->completion);
 217
 218        xadc_zynq_write_fifo(xadc, cmd, ARRAY_SIZE(cmd));
 219        xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &tmp);
 220        tmp &= ~XADC_ZYNQ_CFG_DFIFOTH_MASK;
 221        tmp |= 1 << XADC_ZYNQ_CFG_DFIFOTH_OFFSET;
 222        xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, tmp);
 223
 224        xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH, 0);
 225        spin_unlock_irq(&xadc->lock);
 226        ret = wait_for_completion_interruptible_timeout(&xadc->completion, HZ);
 227        if (ret == 0)
 228                ret = -EIO;
 229        if (ret < 0)
 230                return ret;
 231
 232        xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &resp);
 233        xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &resp);
 234
 235        *val = resp & 0xffff;
 236
 237        return 0;
 238}
 239
 240static unsigned int xadc_zynq_transform_alarm(unsigned int alarm)
 241{
 242        return ((alarm & 0x80) >> 4) |
 243                ((alarm & 0x78) << 1) |
 244                (alarm & 0x07);
 245}
 246
 247/*
 248 * The ZYNQ threshold interrupts are level sensitive. Since we can't make the
 249 * threshold condition go way from within the interrupt handler, this means as
 250 * soon as a threshold condition is present we would enter the interrupt handler
 251 * again and again. To work around this we mask all active thresholds interrupts
 252 * in the interrupt handler and start a timer. In this timer we poll the
 253 * interrupt status and only if the interrupt is inactive we unmask it again.
 254 */
 255static void xadc_zynq_unmask_worker(struct work_struct *work)
 256{
 257        struct xadc *xadc = container_of(work, struct xadc, zynq_unmask_work.work);
 258        unsigned int misc_sts, unmask;
 259
 260        xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &misc_sts);
 261
 262        misc_sts &= XADC_ZYNQ_INT_ALARM_MASK;
 263
 264        spin_lock_irq(&xadc->lock);
 265
 266        /* Clear those bits which are not active anymore */
 267        unmask = (xadc->zynq_masked_alarm ^ misc_sts) & xadc->zynq_masked_alarm;
 268        xadc->zynq_masked_alarm &= misc_sts;
 269
 270        /* Also clear those which are masked out anyway */
 271        xadc->zynq_masked_alarm &= ~xadc->zynq_intmask;
 272
 273        /* Clear the interrupts before we unmask them */
 274        xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, unmask);
 275
 276        xadc_zynq_update_intmsk(xadc, 0, 0);
 277
 278        spin_unlock_irq(&xadc->lock);
 279
 280        /* if still pending some alarm re-trigger the timer */
 281        if (xadc->zynq_masked_alarm) {
 282                schedule_delayed_work(&xadc->zynq_unmask_work,
 283                                msecs_to_jiffies(XADC_ZYNQ_UNMASK_TIMEOUT));
 284        }
 285
 286}
 287
 288static irqreturn_t xadc_zynq_interrupt_handler(int irq, void *devid)
 289{
 290        struct iio_dev *indio_dev = devid;
 291        struct xadc *xadc = iio_priv(indio_dev);
 292        uint32_t status;
 293
 294        xadc_read_reg(xadc, XADC_ZYNQ_REG_INTSTS, &status);
 295
 296        status &= ~(xadc->zynq_intmask | xadc->zynq_masked_alarm);
 297
 298        if (!status)
 299                return IRQ_NONE;
 300
 301        spin_lock(&xadc->lock);
 302
 303        xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, status);
 304
 305        if (status & XADC_ZYNQ_INT_DFIFO_GTH) {
 306                xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH,
 307                        XADC_ZYNQ_INT_DFIFO_GTH);
 308                complete(&xadc->completion);
 309        }
 310
 311        status &= XADC_ZYNQ_INT_ALARM_MASK;
 312        if (status) {
 313                xadc->zynq_masked_alarm |= status;
 314                /*
 315                 * mask the current event interrupt,
 316                 * unmask it when the interrupt is no more active.
 317                 */
 318                xadc_zynq_update_intmsk(xadc, 0, 0);
 319
 320                xadc_handle_events(indio_dev,
 321                                xadc_zynq_transform_alarm(status));
 322
 323                /* unmask the required interrupts in timer. */
 324                schedule_delayed_work(&xadc->zynq_unmask_work,
 325                                msecs_to_jiffies(XADC_ZYNQ_UNMASK_TIMEOUT));
 326        }
 327        spin_unlock(&xadc->lock);
 328
 329        return IRQ_HANDLED;
 330}
 331
 332#define XADC_ZYNQ_TCK_RATE_MAX 50000000
 333#define XADC_ZYNQ_IGAP_DEFAULT 20
 334#define XADC_ZYNQ_PCAP_RATE_MAX 200000000
 335
 336static int xadc_zynq_setup(struct platform_device *pdev,
 337        struct iio_dev *indio_dev, int irq)
 338{
 339        struct xadc *xadc = iio_priv(indio_dev);
 340        unsigned long pcap_rate;
 341        unsigned int tck_div;
 342        unsigned int div;
 343        unsigned int igap;
 344        unsigned int tck_rate;
 345        int ret;
 346
 347        /* TODO: Figure out how to make igap and tck_rate configurable */
 348        igap = XADC_ZYNQ_IGAP_DEFAULT;
 349        tck_rate = XADC_ZYNQ_TCK_RATE_MAX;
 350
 351        xadc->zynq_intmask = ~0;
 352
 353        pcap_rate = clk_get_rate(xadc->clk);
 354        if (!pcap_rate)
 355                return -EINVAL;
 356
 357        if (pcap_rate > XADC_ZYNQ_PCAP_RATE_MAX) {
 358                ret = clk_set_rate(xadc->clk,
 359                                   (unsigned long)XADC_ZYNQ_PCAP_RATE_MAX);
 360                if (ret)
 361                        return ret;
 362        }
 363
 364        if (tck_rate > pcap_rate / 2) {
 365                div = 2;
 366        } else {
 367                div = pcap_rate / tck_rate;
 368                if (pcap_rate / div > XADC_ZYNQ_TCK_RATE_MAX)
 369                        div++;
 370        }
 371
 372        if (div <= 3)
 373                tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV2;
 374        else if (div <= 7)
 375                tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV4;
 376        else if (div <= 15)
 377                tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV8;
 378        else
 379                tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV16;
 380
 381        xadc_write_reg(xadc, XADC_ZYNQ_REG_CTL, XADC_ZYNQ_CTL_RESET);
 382        xadc_write_reg(xadc, XADC_ZYNQ_REG_CTL, 0);
 383        xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, ~0);
 384        xadc_write_reg(xadc, XADC_ZYNQ_REG_INTMSK, xadc->zynq_intmask);
 385        xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, XADC_ZYNQ_CFG_ENABLE |
 386                        XADC_ZYNQ_CFG_REDGE | XADC_ZYNQ_CFG_WEDGE |
 387                        tck_div | XADC_ZYNQ_CFG_IGAP(igap));
 388
 389        if (pcap_rate > XADC_ZYNQ_PCAP_RATE_MAX) {
 390                ret = clk_set_rate(xadc->clk, pcap_rate);
 391                if (ret)
 392                        return ret;
 393        }
 394
 395        return 0;
 396}
 397
 398static unsigned long xadc_zynq_get_dclk_rate(struct xadc *xadc)
 399{
 400        unsigned int div;
 401        uint32_t val;
 402
 403        xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &val);
 404
 405        switch (val & XADC_ZYNQ_CFG_TCKRATE_MASK) {
 406        case XADC_ZYNQ_CFG_TCKRATE_DIV4:
 407                div = 4;
 408                break;
 409        case XADC_ZYNQ_CFG_TCKRATE_DIV8:
 410                div = 8;
 411                break;
 412        case XADC_ZYNQ_CFG_TCKRATE_DIV16:
 413                div = 16;
 414                break;
 415        default:
 416                div = 2;
 417                break;
 418        }
 419
 420        return clk_get_rate(xadc->clk) / div;
 421}
 422
 423static void xadc_zynq_update_alarm(struct xadc *xadc, unsigned int alarm)
 424{
 425        unsigned long flags;
 426        uint32_t status;
 427
 428        /* Move OT to bit 7 */
 429        alarm = ((alarm & 0x08) << 4) | ((alarm & 0xf0) >> 1) | (alarm & 0x07);
 430
 431        spin_lock_irqsave(&xadc->lock, flags);
 432
 433        /* Clear previous interrupts if any. */
 434        xadc_read_reg(xadc, XADC_ZYNQ_REG_INTSTS, &status);
 435        xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, status & alarm);
 436
 437        xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_ALARM_MASK,
 438                ~alarm & XADC_ZYNQ_INT_ALARM_MASK);
 439
 440        spin_unlock_irqrestore(&xadc->lock, flags);
 441}
 442
 443static const struct xadc_ops xadc_zynq_ops = {
 444        .read = xadc_zynq_read_adc_reg,
 445        .write = xadc_zynq_write_adc_reg,
 446        .setup = xadc_zynq_setup,
 447        .get_dclk_rate = xadc_zynq_get_dclk_rate,
 448        .interrupt_handler = xadc_zynq_interrupt_handler,
 449        .update_alarm = xadc_zynq_update_alarm,
 450};
 451
 452static int xadc_axi_read_adc_reg(struct xadc *xadc, unsigned int reg,
 453        uint16_t *val)
 454{
 455        uint32_t val32;
 456
 457        xadc_read_reg(xadc, XADC_AXI_ADC_REG_OFFSET + reg * 4, &val32);
 458        *val = val32 & 0xffff;
 459
 460        return 0;
 461}
 462
 463static int xadc_axi_write_adc_reg(struct xadc *xadc, unsigned int reg,
 464        uint16_t val)
 465{
 466        xadc_write_reg(xadc, XADC_AXI_ADC_REG_OFFSET + reg * 4, val);
 467
 468        return 0;
 469}
 470
 471static int xadc_axi_setup(struct platform_device *pdev,
 472        struct iio_dev *indio_dev, int irq)
 473{
 474        struct xadc *xadc = iio_priv(indio_dev);
 475
 476        xadc_write_reg(xadc, XADC_AXI_REG_RESET, XADC_AXI_RESET_MAGIC);
 477        xadc_write_reg(xadc, XADC_AXI_REG_GIER, XADC_AXI_GIER_ENABLE);
 478
 479        return 0;
 480}
 481
 482static irqreturn_t xadc_axi_interrupt_handler(int irq, void *devid)
 483{
 484        struct iio_dev *indio_dev = devid;
 485        struct xadc *xadc = iio_priv(indio_dev);
 486        uint32_t status, mask;
 487        unsigned int events;
 488
 489        xadc_read_reg(xadc, XADC_AXI_REG_IPISR, &status);
 490        xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &mask);
 491        status &= mask;
 492
 493        if (!status)
 494                return IRQ_NONE;
 495
 496        if ((status & XADC_AXI_INT_EOS) && xadc->trigger)
 497                iio_trigger_poll(xadc->trigger);
 498
 499        if (status & XADC_AXI_INT_ALARM_MASK) {
 500                /*
 501                 * The order of the bits in the AXI-XADC status register does
 502                 * not match the order of the bits in the XADC alarm enable
 503                 * register. xadc_handle_events() expects the events to be in
 504                 * the same order as the XADC alarm enable register.
 505                 */
 506                events = (status & 0x000e) >> 1;
 507                events |= (status & 0x0001) << 3;
 508                events |= (status & 0x3c00) >> 6;
 509                xadc_handle_events(indio_dev, events);
 510        }
 511
 512        xadc_write_reg(xadc, XADC_AXI_REG_IPISR, status);
 513
 514        return IRQ_HANDLED;
 515}
 516
 517static void xadc_axi_update_alarm(struct xadc *xadc, unsigned int alarm)
 518{
 519        uint32_t val;
 520        unsigned long flags;
 521
 522        /*
 523         * The order of the bits in the AXI-XADC status register does not match
 524         * the order of the bits in the XADC alarm enable register. We get
 525         * passed the alarm mask in the same order as in the XADC alarm enable
 526         * register.
 527         */
 528        alarm = ((alarm & 0x07) << 1) | ((alarm & 0x08) >> 3) |
 529                        ((alarm & 0xf0) << 6);
 530
 531        spin_lock_irqsave(&xadc->lock, flags);
 532        xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val);
 533        val &= ~XADC_AXI_INT_ALARM_MASK;
 534        val |= alarm;
 535        xadc_write_reg(xadc, XADC_AXI_REG_IPIER, val);
 536        spin_unlock_irqrestore(&xadc->lock, flags);
 537}
 538
 539static unsigned long xadc_axi_get_dclk(struct xadc *xadc)
 540{
 541        return clk_get_rate(xadc->clk);
 542}
 543
 544static const struct xadc_ops xadc_axi_ops = {
 545        .read = xadc_axi_read_adc_reg,
 546        .write = xadc_axi_write_adc_reg,
 547        .setup = xadc_axi_setup,
 548        .get_dclk_rate = xadc_axi_get_dclk,
 549        .update_alarm = xadc_axi_update_alarm,
 550        .interrupt_handler = xadc_axi_interrupt_handler,
 551        .flags = XADC_FLAGS_BUFFERED,
 552};
 553
 554static int _xadc_update_adc_reg(struct xadc *xadc, unsigned int reg,
 555        uint16_t mask, uint16_t val)
 556{
 557        uint16_t tmp;
 558        int ret;
 559
 560        ret = _xadc_read_adc_reg(xadc, reg, &tmp);
 561        if (ret)
 562                return ret;
 563
 564        return _xadc_write_adc_reg(xadc, reg, (tmp & ~mask) | val);
 565}
 566
 567static int xadc_update_adc_reg(struct xadc *xadc, unsigned int reg,
 568        uint16_t mask, uint16_t val)
 569{
 570        int ret;
 571
 572        mutex_lock(&xadc->mutex);
 573        ret = _xadc_update_adc_reg(xadc, reg, mask, val);
 574        mutex_unlock(&xadc->mutex);
 575
 576        return ret;
 577}
 578
 579static unsigned long xadc_get_dclk_rate(struct xadc *xadc)
 580{
 581        return xadc->ops->get_dclk_rate(xadc);
 582}
 583
 584static int xadc_update_scan_mode(struct iio_dev *indio_dev,
 585        const unsigned long *mask)
 586{
 587        struct xadc *xadc = iio_priv(indio_dev);
 588        unsigned int n;
 589
 590        n = bitmap_weight(mask, indio_dev->masklength);
 591
 592        kfree(xadc->data);
 593        xadc->data = kcalloc(n, sizeof(*xadc->data), GFP_KERNEL);
 594        if (!xadc->data)
 595                return -ENOMEM;
 596
 597        return 0;
 598}
 599
 600static unsigned int xadc_scan_index_to_channel(unsigned int scan_index)
 601{
 602        switch (scan_index) {
 603        case 5:
 604                return XADC_REG_VCCPINT;
 605        case 6:
 606                return XADC_REG_VCCPAUX;
 607        case 7:
 608                return XADC_REG_VCCO_DDR;
 609        case 8:
 610                return XADC_REG_TEMP;
 611        case 9:
 612                return XADC_REG_VCCINT;
 613        case 10:
 614                return XADC_REG_VCCAUX;
 615        case 11:
 616                return XADC_REG_VPVN;
 617        case 12:
 618                return XADC_REG_VREFP;
 619        case 13:
 620                return XADC_REG_VREFN;
 621        case 14:
 622                return XADC_REG_VCCBRAM;
 623        default:
 624                return XADC_REG_VAUX(scan_index - 16);
 625        }
 626}
 627
 628static irqreturn_t xadc_trigger_handler(int irq, void *p)
 629{
 630        struct iio_poll_func *pf = p;
 631        struct iio_dev *indio_dev = pf->indio_dev;
 632        struct xadc *xadc = iio_priv(indio_dev);
 633        unsigned int chan;
 634        int i, j;
 635
 636        if (!xadc->data)
 637                goto out;
 638
 639        j = 0;
 640        for_each_set_bit(i, indio_dev->active_scan_mask,
 641                indio_dev->masklength) {
 642                chan = xadc_scan_index_to_channel(i);
 643                xadc_read_adc_reg(xadc, chan, &xadc->data[j]);
 644                j++;
 645        }
 646
 647        iio_push_to_buffers(indio_dev, xadc->data);
 648
 649out:
 650        iio_trigger_notify_done(indio_dev->trig);
 651
 652        return IRQ_HANDLED;
 653}
 654
 655static int xadc_trigger_set_state(struct iio_trigger *trigger, bool state)
 656{
 657        struct xadc *xadc = iio_trigger_get_drvdata(trigger);
 658        unsigned long flags;
 659        unsigned int convst;
 660        unsigned int val;
 661        int ret = 0;
 662
 663        mutex_lock(&xadc->mutex);
 664
 665        if (state) {
 666                /* Only one of the two triggers can be active at a time. */
 667                if (xadc->trigger != NULL) {
 668                        ret = -EBUSY;
 669                        goto err_out;
 670                } else {
 671                        xadc->trigger = trigger;
 672                        if (trigger == xadc->convst_trigger)
 673                                convst = XADC_CONF0_EC;
 674                        else
 675                                convst = 0;
 676                }
 677                ret = _xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF0_EC,
 678                                        convst);
 679                if (ret)
 680                        goto err_out;
 681        } else {
 682                xadc->trigger = NULL;
 683        }
 684
 685        spin_lock_irqsave(&xadc->lock, flags);
 686        xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val);
 687        xadc_write_reg(xadc, XADC_AXI_REG_IPISR, XADC_AXI_INT_EOS);
 688        if (state)
 689                val |= XADC_AXI_INT_EOS;
 690        else
 691                val &= ~XADC_AXI_INT_EOS;
 692        xadc_write_reg(xadc, XADC_AXI_REG_IPIER, val);
 693        spin_unlock_irqrestore(&xadc->lock, flags);
 694
 695err_out:
 696        mutex_unlock(&xadc->mutex);
 697
 698        return ret;
 699}
 700
 701static const struct iio_trigger_ops xadc_trigger_ops = {
 702        .set_trigger_state = &xadc_trigger_set_state,
 703};
 704
 705static struct iio_trigger *xadc_alloc_trigger(struct iio_dev *indio_dev,
 706        const char *name)
 707{
 708        struct iio_trigger *trig;
 709        int ret;
 710
 711        trig = iio_trigger_alloc("%s%d-%s", indio_dev->name,
 712                                indio_dev->id, name);
 713        if (trig == NULL)
 714                return ERR_PTR(-ENOMEM);
 715
 716        trig->dev.parent = indio_dev->dev.parent;
 717        trig->ops = &xadc_trigger_ops;
 718        iio_trigger_set_drvdata(trig, iio_priv(indio_dev));
 719
 720        ret = iio_trigger_register(trig);
 721        if (ret)
 722                goto error_free_trig;
 723
 724        return trig;
 725
 726error_free_trig:
 727        iio_trigger_free(trig);
 728        return ERR_PTR(ret);
 729}
 730
 731static int xadc_power_adc_b(struct xadc *xadc, unsigned int seq_mode)
 732{
 733        uint16_t val;
 734
 735        /* Powerdown the ADC-B when it is not needed. */
 736        switch (seq_mode) {
 737        case XADC_CONF1_SEQ_SIMULTANEOUS:
 738        case XADC_CONF1_SEQ_INDEPENDENT:
 739                val = 0;
 740                break;
 741        default:
 742                val = XADC_CONF2_PD_ADC_B;
 743                break;
 744        }
 745
 746        return xadc_update_adc_reg(xadc, XADC_REG_CONF2, XADC_CONF2_PD_MASK,
 747                val);
 748}
 749
 750static int xadc_get_seq_mode(struct xadc *xadc, unsigned long scan_mode)
 751{
 752        unsigned int aux_scan_mode = scan_mode >> 16;
 753
 754        if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_DUAL)
 755                return XADC_CONF1_SEQ_SIMULTANEOUS;
 756
 757        if ((aux_scan_mode & 0xff00) == 0 ||
 758                (aux_scan_mode & 0x00ff) == 0)
 759                return XADC_CONF1_SEQ_CONTINUOUS;
 760
 761        return XADC_CONF1_SEQ_SIMULTANEOUS;
 762}
 763
 764static int xadc_postdisable(struct iio_dev *indio_dev)
 765{
 766        struct xadc *xadc = iio_priv(indio_dev);
 767        unsigned long scan_mask;
 768        int ret;
 769        int i;
 770
 771        scan_mask = 1; /* Run calibration as part of the sequence */
 772        for (i = 0; i < indio_dev->num_channels; i++)
 773                scan_mask |= BIT(indio_dev->channels[i].scan_index);
 774
 775        /* Enable all channels and calibration */
 776        ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(0), scan_mask & 0xffff);
 777        if (ret)
 778                return ret;
 779
 780        ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16);
 781        if (ret)
 782                return ret;
 783
 784        ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
 785                XADC_CONF1_SEQ_CONTINUOUS);
 786        if (ret)
 787                return ret;
 788
 789        return xadc_power_adc_b(xadc, XADC_CONF1_SEQ_CONTINUOUS);
 790}
 791
 792static int xadc_preenable(struct iio_dev *indio_dev)
 793{
 794        struct xadc *xadc = iio_priv(indio_dev);
 795        unsigned long scan_mask;
 796        int seq_mode;
 797        int ret;
 798
 799        ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
 800                XADC_CONF1_SEQ_DEFAULT);
 801        if (ret)
 802                goto err;
 803
 804        scan_mask = *indio_dev->active_scan_mask;
 805        seq_mode = xadc_get_seq_mode(xadc, scan_mask);
 806
 807        ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(0), scan_mask & 0xffff);
 808        if (ret)
 809                goto err;
 810
 811        /*
 812         * In simultaneous mode the upper and lower aux channels are samples at
 813         * the same time. In this mode the upper 8 bits in the sequencer
 814         * register are don't care and the lower 8 bits control two channels
 815         * each. As such we must set the bit if either the channel in the lower
 816         * group or the upper group is enabled.
 817         */
 818        if (seq_mode == XADC_CONF1_SEQ_SIMULTANEOUS)
 819                scan_mask = ((scan_mask >> 8) | scan_mask) & 0xff0000;
 820
 821        ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16);
 822        if (ret)
 823                goto err;
 824
 825        ret = xadc_power_adc_b(xadc, seq_mode);
 826        if (ret)
 827                goto err;
 828
 829        ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
 830                seq_mode);
 831        if (ret)
 832                goto err;
 833
 834        return 0;
 835err:
 836        xadc_postdisable(indio_dev);
 837        return ret;
 838}
 839
 840static const struct iio_buffer_setup_ops xadc_buffer_ops = {
 841        .preenable = &xadc_preenable,
 842        .postdisable = &xadc_postdisable,
 843};
 844
 845static int xadc_read_samplerate(struct xadc *xadc)
 846{
 847        unsigned int div;
 848        uint16_t val16;
 849        int ret;
 850
 851        ret = xadc_read_adc_reg(xadc, XADC_REG_CONF2, &val16);
 852        if (ret)
 853                return ret;
 854
 855        div = (val16 & XADC_CONF2_DIV_MASK) >> XADC_CONF2_DIV_OFFSET;
 856        if (div < 2)
 857                div = 2;
 858
 859        return xadc_get_dclk_rate(xadc) / div / 26;
 860}
 861
 862static int xadc_read_raw(struct iio_dev *indio_dev,
 863        struct iio_chan_spec const *chan, int *val, int *val2, long info)
 864{
 865        struct xadc *xadc = iio_priv(indio_dev);
 866        uint16_t val16;
 867        int ret;
 868
 869        switch (info) {
 870        case IIO_CHAN_INFO_RAW:
 871                if (iio_buffer_enabled(indio_dev))
 872                        return -EBUSY;
 873                ret = xadc_read_adc_reg(xadc, chan->address, &val16);
 874                if (ret < 0)
 875                        return ret;
 876
 877                val16 >>= 4;
 878                if (chan->scan_type.sign == 'u')
 879                        *val = val16;
 880                else
 881                        *val = sign_extend32(val16, 11);
 882
 883                return IIO_VAL_INT;
 884        case IIO_CHAN_INFO_SCALE:
 885                switch (chan->type) {
 886                case IIO_VOLTAGE:
 887                        /* V = (val * 3.0) / 4096 */
 888                        switch (chan->address) {
 889                        case XADC_REG_VCCINT:
 890                        case XADC_REG_VCCAUX:
 891                        case XADC_REG_VREFP:
 892                        case XADC_REG_VREFN:
 893                        case XADC_REG_VCCBRAM:
 894                        case XADC_REG_VCCPINT:
 895                        case XADC_REG_VCCPAUX:
 896                        case XADC_REG_VCCO_DDR:
 897                                *val = 3000;
 898                                break;
 899                        default:
 900                                *val = 1000;
 901                                break;
 902                        }
 903                        *val2 = 12;
 904                        return IIO_VAL_FRACTIONAL_LOG2;
 905                case IIO_TEMP:
 906                        /* Temp in C = (val * 503.975) / 4096 - 273.15 */
 907                        *val = 503975;
 908                        *val2 = 12;
 909                        return IIO_VAL_FRACTIONAL_LOG2;
 910                default:
 911                        return -EINVAL;
 912                }
 913        case IIO_CHAN_INFO_OFFSET:
 914                /* Only the temperature channel has an offset */
 915                *val = -((273150 << 12) / 503975);
 916                return IIO_VAL_INT;
 917        case IIO_CHAN_INFO_SAMP_FREQ:
 918                ret = xadc_read_samplerate(xadc);
 919                if (ret < 0)
 920                        return ret;
 921
 922                *val = ret;
 923                return IIO_VAL_INT;
 924        default:
 925                return -EINVAL;
 926        }
 927}
 928
 929static int xadc_write_samplerate(struct xadc *xadc, int val)
 930{
 931        unsigned long clk_rate = xadc_get_dclk_rate(xadc);
 932        unsigned int div;
 933
 934        if (!clk_rate)
 935                return -EINVAL;
 936
 937        if (val <= 0)
 938                return -EINVAL;
 939
 940        /* Max. 150 kSPS */
 941        if (val > XADC_MAX_SAMPLERATE)
 942                val = XADC_MAX_SAMPLERATE;
 943
 944        val *= 26;
 945
 946        /* Min 1MHz */
 947        if (val < 1000000)
 948                val = 1000000;
 949
 950        /*
 951         * We want to round down, but only if we do not exceed the 150 kSPS
 952         * limit.
 953         */
 954        div = clk_rate / val;
 955        if (clk_rate / div / 26 > XADC_MAX_SAMPLERATE)
 956                div++;
 957        if (div < 2)
 958                div = 2;
 959        else if (div > 0xff)
 960                div = 0xff;
 961
 962        return xadc_update_adc_reg(xadc, XADC_REG_CONF2, XADC_CONF2_DIV_MASK,
 963                div << XADC_CONF2_DIV_OFFSET);
 964}
 965
 966static int xadc_write_raw(struct iio_dev *indio_dev,
 967        struct iio_chan_spec const *chan, int val, int val2, long info)
 968{
 969        struct xadc *xadc = iio_priv(indio_dev);
 970
 971        if (info != IIO_CHAN_INFO_SAMP_FREQ)
 972                return -EINVAL;
 973
 974        return xadc_write_samplerate(xadc, val);
 975}
 976
 977static const struct iio_event_spec xadc_temp_events[] = {
 978        {
 979                .type = IIO_EV_TYPE_THRESH,
 980                .dir = IIO_EV_DIR_RISING,
 981                .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
 982                                BIT(IIO_EV_INFO_VALUE) |
 983                                BIT(IIO_EV_INFO_HYSTERESIS),
 984        },
 985};
 986
 987/* Separate values for upper and lower thresholds, but only a shared enabled */
 988static const struct iio_event_spec xadc_voltage_events[] = {
 989        {
 990                .type = IIO_EV_TYPE_THRESH,
 991                .dir = IIO_EV_DIR_RISING,
 992                .mask_separate = BIT(IIO_EV_INFO_VALUE),
 993        }, {
 994                .type = IIO_EV_TYPE_THRESH,
 995                .dir = IIO_EV_DIR_FALLING,
 996                .mask_separate = BIT(IIO_EV_INFO_VALUE),
 997        }, {
 998                .type = IIO_EV_TYPE_THRESH,
 999                .dir = IIO_EV_DIR_EITHER,
1000                .mask_separate = BIT(IIO_EV_INFO_ENABLE),
1001        },
1002};
1003
1004#define XADC_CHAN_TEMP(_chan, _scan_index, _addr) { \
1005        .type = IIO_TEMP, \
1006        .indexed = 1, \
1007        .channel = (_chan), \
1008        .address = (_addr), \
1009        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
1010                BIT(IIO_CHAN_INFO_SCALE) | \
1011                BIT(IIO_CHAN_INFO_OFFSET), \
1012        .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
1013        .event_spec = xadc_temp_events, \
1014        .num_event_specs = ARRAY_SIZE(xadc_temp_events), \
1015        .scan_index = (_scan_index), \
1016        .scan_type = { \
1017                .sign = 'u', \
1018                .realbits = 12, \
1019                .storagebits = 16, \
1020                .shift = 4, \
1021                .endianness = IIO_CPU, \
1022        }, \
1023}
1024
1025#define XADC_CHAN_VOLTAGE(_chan, _scan_index, _addr, _ext, _alarm) { \
1026        .type = IIO_VOLTAGE, \
1027        .indexed = 1, \
1028        .channel = (_chan), \
1029        .address = (_addr), \
1030        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
1031                BIT(IIO_CHAN_INFO_SCALE), \
1032        .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
1033        .event_spec = (_alarm) ? xadc_voltage_events : NULL, \
1034        .num_event_specs = (_alarm) ? ARRAY_SIZE(xadc_voltage_events) : 0, \
1035        .scan_index = (_scan_index), \
1036        .scan_type = { \
1037                .sign = ((_addr) == XADC_REG_VREFN) ? 's' : 'u', \
1038                .realbits = 12, \
1039                .storagebits = 16, \
1040                .shift = 4, \
1041                .endianness = IIO_CPU, \
1042        }, \
1043        .extend_name = _ext, \
1044}
1045
1046static const struct iio_chan_spec xadc_channels[] = {
1047        XADC_CHAN_TEMP(0, 8, XADC_REG_TEMP),
1048        XADC_CHAN_VOLTAGE(0, 9, XADC_REG_VCCINT, "vccint", true),
1049        XADC_CHAN_VOLTAGE(1, 10, XADC_REG_VCCAUX, "vccaux", true),
1050        XADC_CHAN_VOLTAGE(2, 14, XADC_REG_VCCBRAM, "vccbram", true),
1051        XADC_CHAN_VOLTAGE(3, 5, XADC_REG_VCCPINT, "vccpint", true),
1052        XADC_CHAN_VOLTAGE(4, 6, XADC_REG_VCCPAUX, "vccpaux", true),
1053        XADC_CHAN_VOLTAGE(5, 7, XADC_REG_VCCO_DDR, "vccoddr", true),
1054        XADC_CHAN_VOLTAGE(6, 12, XADC_REG_VREFP, "vrefp", false),
1055        XADC_CHAN_VOLTAGE(7, 13, XADC_REG_VREFN, "vrefn", false),
1056        XADC_CHAN_VOLTAGE(8, 11, XADC_REG_VPVN, NULL, false),
1057        XADC_CHAN_VOLTAGE(9, 16, XADC_REG_VAUX(0), NULL, false),
1058        XADC_CHAN_VOLTAGE(10, 17, XADC_REG_VAUX(1), NULL, false),
1059        XADC_CHAN_VOLTAGE(11, 18, XADC_REG_VAUX(2), NULL, false),
1060        XADC_CHAN_VOLTAGE(12, 19, XADC_REG_VAUX(3), NULL, false),
1061        XADC_CHAN_VOLTAGE(13, 20, XADC_REG_VAUX(4), NULL, false),
1062        XADC_CHAN_VOLTAGE(14, 21, XADC_REG_VAUX(5), NULL, false),
1063        XADC_CHAN_VOLTAGE(15, 22, XADC_REG_VAUX(6), NULL, false),
1064        XADC_CHAN_VOLTAGE(16, 23, XADC_REG_VAUX(7), NULL, false),
1065        XADC_CHAN_VOLTAGE(17, 24, XADC_REG_VAUX(8), NULL, false),
1066        XADC_CHAN_VOLTAGE(18, 25, XADC_REG_VAUX(9), NULL, false),
1067        XADC_CHAN_VOLTAGE(19, 26, XADC_REG_VAUX(10), NULL, false),
1068        XADC_CHAN_VOLTAGE(20, 27, XADC_REG_VAUX(11), NULL, false),
1069        XADC_CHAN_VOLTAGE(21, 28, XADC_REG_VAUX(12), NULL, false),
1070        XADC_CHAN_VOLTAGE(22, 29, XADC_REG_VAUX(13), NULL, false),
1071        XADC_CHAN_VOLTAGE(23, 30, XADC_REG_VAUX(14), NULL, false),
1072        XADC_CHAN_VOLTAGE(24, 31, XADC_REG_VAUX(15), NULL, false),
1073};
1074
1075static const struct iio_info xadc_info = {
1076        .read_raw = &xadc_read_raw,
1077        .write_raw = &xadc_write_raw,
1078        .read_event_config = &xadc_read_event_config,
1079        .write_event_config = &xadc_write_event_config,
1080        .read_event_value = &xadc_read_event_value,
1081        .write_event_value = &xadc_write_event_value,
1082        .update_scan_mode = &xadc_update_scan_mode,
1083};
1084
1085static const struct of_device_id xadc_of_match_table[] = {
1086        { .compatible = "xlnx,zynq-xadc-1.00.a", (void *)&xadc_zynq_ops },
1087        { .compatible = "xlnx,axi-xadc-1.00.a", (void *)&xadc_axi_ops },
1088        { },
1089};
1090MODULE_DEVICE_TABLE(of, xadc_of_match_table);
1091
1092static int xadc_parse_dt(struct iio_dev *indio_dev, struct device_node *np,
1093        unsigned int *conf)
1094{
1095        struct device *dev = indio_dev->dev.parent;
1096        struct xadc *xadc = iio_priv(indio_dev);
1097        struct iio_chan_spec *channels, *chan;
1098        struct device_node *chan_node, *child;
1099        unsigned int num_channels;
1100        const char *external_mux;
1101        u32 ext_mux_chan;
1102        u32 reg;
1103        int ret;
1104
1105        *conf = 0;
1106
1107        ret = of_property_read_string(np, "xlnx,external-mux", &external_mux);
1108        if (ret < 0 || strcasecmp(external_mux, "none") == 0)
1109                xadc->external_mux_mode = XADC_EXTERNAL_MUX_NONE;
1110        else if (strcasecmp(external_mux, "single") == 0)
1111                xadc->external_mux_mode = XADC_EXTERNAL_MUX_SINGLE;
1112        else if (strcasecmp(external_mux, "dual") == 0)
1113                xadc->external_mux_mode = XADC_EXTERNAL_MUX_DUAL;
1114        else
1115                return -EINVAL;
1116
1117        if (xadc->external_mux_mode != XADC_EXTERNAL_MUX_NONE) {
1118                ret = of_property_read_u32(np, "xlnx,external-mux-channel",
1119                                        &ext_mux_chan);
1120                if (ret < 0)
1121                        return ret;
1122
1123                if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_SINGLE) {
1124                        if (ext_mux_chan == 0)
1125                                ext_mux_chan = XADC_REG_VPVN;
1126                        else if (ext_mux_chan <= 16)
1127                                ext_mux_chan = XADC_REG_VAUX(ext_mux_chan - 1);
1128                        else
1129                                return -EINVAL;
1130                } else {
1131                        if (ext_mux_chan > 0 && ext_mux_chan <= 8)
1132                                ext_mux_chan = XADC_REG_VAUX(ext_mux_chan - 1);
1133                        else
1134                                return -EINVAL;
1135                }
1136
1137                *conf |= XADC_CONF0_MUX | XADC_CONF0_CHAN(ext_mux_chan);
1138        }
1139
1140        channels = devm_kmemdup(dev, xadc_channels,
1141                                sizeof(xadc_channels), GFP_KERNEL);
1142        if (!channels)
1143                return -ENOMEM;
1144
1145        num_channels = 9;
1146        chan = &channels[9];
1147
1148        chan_node = of_get_child_by_name(np, "xlnx,channels");
1149        if (chan_node) {
1150                for_each_child_of_node(chan_node, child) {
1151                        if (num_channels >= ARRAY_SIZE(xadc_channels)) {
1152                                of_node_put(child);
1153                                break;
1154                        }
1155
1156                        ret = of_property_read_u32(child, "reg", &reg);
1157                        if (ret || reg > 16)
1158                                continue;
1159
1160                        if (of_property_read_bool(child, "xlnx,bipolar"))
1161                                chan->scan_type.sign = 's';
1162
1163                        if (reg == 0) {
1164                                chan->scan_index = 11;
1165                                chan->address = XADC_REG_VPVN;
1166                        } else {
1167                                chan->scan_index = 15 + reg;
1168                                chan->address = XADC_REG_VAUX(reg - 1);
1169                        }
1170                        num_channels++;
1171                        chan++;
1172                }
1173        }
1174        of_node_put(chan_node);
1175
1176        indio_dev->num_channels = num_channels;
1177        indio_dev->channels = devm_krealloc(dev, channels,
1178                                            sizeof(*channels) * num_channels,
1179                                            GFP_KERNEL);
1180        /* If we can't resize the channels array, just use the original */
1181        if (!indio_dev->channels)
1182                indio_dev->channels = channels;
1183
1184        return 0;
1185}
1186
1187static int xadc_probe(struct platform_device *pdev)
1188{
1189        const struct of_device_id *id;
1190        struct iio_dev *indio_dev;
1191        unsigned int bipolar_mask;
1192        unsigned int conf0;
1193        struct xadc *xadc;
1194        int ret;
1195        int irq;
1196        int i;
1197
1198        if (!pdev->dev.of_node)
1199                return -ENODEV;
1200
1201        id = of_match_node(xadc_of_match_table, pdev->dev.of_node);
1202        if (!id)
1203                return -EINVAL;
1204
1205        irq = platform_get_irq(pdev, 0);
1206        if (irq <= 0)
1207                return -ENXIO;
1208
1209        indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*xadc));
1210        if (!indio_dev)
1211                return -ENOMEM;
1212
1213        xadc = iio_priv(indio_dev);
1214        xadc->ops = id->data;
1215        xadc->irq = irq;
1216        init_completion(&xadc->completion);
1217        mutex_init(&xadc->mutex);
1218        spin_lock_init(&xadc->lock);
1219        INIT_DELAYED_WORK(&xadc->zynq_unmask_work, xadc_zynq_unmask_worker);
1220
1221        xadc->base = devm_platform_ioremap_resource(pdev, 0);
1222        if (IS_ERR(xadc->base))
1223                return PTR_ERR(xadc->base);
1224
1225        indio_dev->name = "xadc";
1226        indio_dev->modes = INDIO_DIRECT_MODE;
1227        indio_dev->info = &xadc_info;
1228
1229        ret = xadc_parse_dt(indio_dev, pdev->dev.of_node, &conf0);
1230        if (ret)
1231                return ret;
1232
1233        if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
1234                ret = iio_triggered_buffer_setup(indio_dev,
1235                        &iio_pollfunc_store_time, &xadc_trigger_handler,
1236                        &xadc_buffer_ops);
1237                if (ret)
1238                        return ret;
1239
1240                xadc->convst_trigger = xadc_alloc_trigger(indio_dev, "convst");
1241                if (IS_ERR(xadc->convst_trigger)) {
1242                        ret = PTR_ERR(xadc->convst_trigger);
1243                        goto err_triggered_buffer_cleanup;
1244                }
1245                xadc->samplerate_trigger = xadc_alloc_trigger(indio_dev,
1246                        "samplerate");
1247                if (IS_ERR(xadc->samplerate_trigger)) {
1248                        ret = PTR_ERR(xadc->samplerate_trigger);
1249                        goto err_free_convst_trigger;
1250                }
1251        }
1252
1253        xadc->clk = devm_clk_get(&pdev->dev, NULL);
1254        if (IS_ERR(xadc->clk)) {
1255                ret = PTR_ERR(xadc->clk);
1256                goto err_free_samplerate_trigger;
1257        }
1258
1259        ret = clk_prepare_enable(xadc->clk);
1260        if (ret)
1261                goto err_free_samplerate_trigger;
1262
1263        /*
1264         * Make sure not to exceed the maximum samplerate since otherwise the
1265         * resulting interrupt storm will soft-lock the system.
1266         */
1267        if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
1268                ret = xadc_read_samplerate(xadc);
1269                if (ret < 0)
1270                        goto err_free_samplerate_trigger;
1271                if (ret > XADC_MAX_SAMPLERATE) {
1272                        ret = xadc_write_samplerate(xadc, XADC_MAX_SAMPLERATE);
1273                        if (ret < 0)
1274                                goto err_free_samplerate_trigger;
1275                }
1276        }
1277
1278        ret = request_irq(xadc->irq, xadc->ops->interrupt_handler, 0,
1279                        dev_name(&pdev->dev), indio_dev);
1280        if (ret)
1281                goto err_clk_disable_unprepare;
1282
1283        ret = xadc->ops->setup(pdev, indio_dev, xadc->irq);
1284        if (ret)
1285                goto err_free_irq;
1286
1287        for (i = 0; i < 16; i++)
1288                xadc_read_adc_reg(xadc, XADC_REG_THRESHOLD(i),
1289                        &xadc->threshold[i]);
1290
1291        ret = xadc_write_adc_reg(xadc, XADC_REG_CONF0, conf0);
1292        if (ret)
1293                goto err_free_irq;
1294
1295        bipolar_mask = 0;
1296        for (i = 0; i < indio_dev->num_channels; i++) {
1297                if (indio_dev->channels[i].scan_type.sign == 's')
1298                        bipolar_mask |= BIT(indio_dev->channels[i].scan_index);
1299        }
1300
1301        ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(0), bipolar_mask);
1302        if (ret)
1303                goto err_free_irq;
1304        ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(1),
1305                bipolar_mask >> 16);
1306        if (ret)
1307                goto err_free_irq;
1308
1309        /* Disable all alarms */
1310        ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_ALARM_MASK,
1311                                  XADC_CONF1_ALARM_MASK);
1312        if (ret)
1313                goto err_free_irq;
1314
1315        /* Set thresholds to min/max */
1316        for (i = 0; i < 16; i++) {
1317                /*
1318                 * Set max voltage threshold and both temperature thresholds to
1319                 * 0xffff, min voltage threshold to 0.
1320                 */
1321                if (i % 8 < 4 || i == 7)
1322                        xadc->threshold[i] = 0xffff;
1323                else
1324                        xadc->threshold[i] = 0;
1325                ret = xadc_write_adc_reg(xadc, XADC_REG_THRESHOLD(i),
1326                        xadc->threshold[i]);
1327                if (ret)
1328                        goto err_free_irq;
1329        }
1330
1331        /* Go to non-buffered mode */
1332        xadc_postdisable(indio_dev);
1333
1334        ret = iio_device_register(indio_dev);
1335        if (ret)
1336                goto err_free_irq;
1337
1338        platform_set_drvdata(pdev, indio_dev);
1339
1340        return 0;
1341
1342err_free_irq:
1343        free_irq(xadc->irq, indio_dev);
1344        cancel_delayed_work_sync(&xadc->zynq_unmask_work);
1345err_clk_disable_unprepare:
1346        clk_disable_unprepare(xadc->clk);
1347err_free_samplerate_trigger:
1348        if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
1349                iio_trigger_free(xadc->samplerate_trigger);
1350err_free_convst_trigger:
1351        if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
1352                iio_trigger_free(xadc->convst_trigger);
1353err_triggered_buffer_cleanup:
1354        if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
1355                iio_triggered_buffer_cleanup(indio_dev);
1356
1357        return ret;
1358}
1359
1360static int xadc_remove(struct platform_device *pdev)
1361{
1362        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
1363        struct xadc *xadc = iio_priv(indio_dev);
1364
1365        iio_device_unregister(indio_dev);
1366        if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
1367                iio_trigger_free(xadc->samplerate_trigger);
1368                iio_trigger_free(xadc->convst_trigger);
1369                iio_triggered_buffer_cleanup(indio_dev);
1370        }
1371        free_irq(xadc->irq, indio_dev);
1372        cancel_delayed_work_sync(&xadc->zynq_unmask_work);
1373        clk_disable_unprepare(xadc->clk);
1374        kfree(xadc->data);
1375
1376        return 0;
1377}
1378
1379static struct platform_driver xadc_driver = {
1380        .probe = xadc_probe,
1381        .remove = xadc_remove,
1382        .driver = {
1383                .name = "xadc",
1384                .of_match_table = xadc_of_match_table,
1385        },
1386};
1387module_platform_driver(xadc_driver);
1388
1389MODULE_LICENSE("GPL v2");
1390MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
1391MODULE_DESCRIPTION("Xilinx XADC IIO driver");
1392