linux/drivers/iio/adc/at91_adc.c
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   1/*
   2 * Driver for the ADC present in the Atmel AT91 evaluation boards.
   3 *
   4 * Copyright 2011 Free Electrons
   5 *
   6 * Licensed under the GPLv2 or later.
   7 */
   8
   9#include <linux/bitmap.h>
  10#include <linux/bitops.h>
  11#include <linux/clk.h>
  12#include <linux/err.h>
  13#include <linux/io.h>
  14#include <linux/input.h>
  15#include <linux/interrupt.h>
  16#include <linux/jiffies.h>
  17#include <linux/kernel.h>
  18#include <linux/module.h>
  19#include <linux/of.h>
  20#include <linux/of_device.h>
  21#include <linux/platform_device.h>
  22#include <linux/sched.h>
  23#include <linux/slab.h>
  24#include <linux/wait.h>
  25
  26#include <linux/platform_data/at91_adc.h>
  27
  28#include <linux/iio/iio.h>
  29#include <linux/iio/buffer.h>
  30#include <linux/iio/trigger.h>
  31#include <linux/iio/trigger_consumer.h>
  32#include <linux/iio/triggered_buffer.h>
  33#include <linux/pinctrl/consumer.h>
  34
  35/* Registers */
  36#define AT91_ADC_CR             0x00            /* Control Register */
  37#define         AT91_ADC_SWRST          (1 << 0)        /* Software Reset */
  38#define         AT91_ADC_START          (1 << 1)        /* Start Conversion */
  39
  40#define AT91_ADC_MR             0x04            /* Mode Register */
  41#define         AT91_ADC_TSAMOD         (3 << 0)        /* ADC mode */
  42#define         AT91_ADC_TSAMOD_ADC_ONLY_MODE           (0 << 0)        /* ADC Mode */
  43#define         AT91_ADC_TSAMOD_TS_ONLY_MODE            (1 << 0)        /* Touch Screen Only Mode */
  44#define         AT91_ADC_TRGEN          (1 << 0)        /* Trigger Enable */
  45#define         AT91_ADC_TRGSEL         (7 << 1)        /* Trigger Selection */
  46#define                 AT91_ADC_TRGSEL_TC0             (0 << 1)
  47#define                 AT91_ADC_TRGSEL_TC1             (1 << 1)
  48#define                 AT91_ADC_TRGSEL_TC2             (2 << 1)
  49#define                 AT91_ADC_TRGSEL_EXTERNAL        (6 << 1)
  50#define         AT91_ADC_LOWRES         (1 << 4)        /* Low Resolution */
  51#define         AT91_ADC_SLEEP          (1 << 5)        /* Sleep Mode */
  52#define         AT91_ADC_PENDET         (1 << 6)        /* Pen contact detection enable */
  53#define         AT91_ADC_PRESCAL_9260   (0x3f << 8)     /* Prescalar Rate Selection */
  54#define         AT91_ADC_PRESCAL_9G45   (0xff << 8)
  55#define                 AT91_ADC_PRESCAL_(x)    ((x) << 8)
  56#define         AT91_ADC_STARTUP_9260   (0x1f << 16)    /* Startup Up Time */
  57#define         AT91_ADC_STARTUP_9G45   (0x7f << 16)
  58#define         AT91_ADC_STARTUP_9X5    (0xf << 16)
  59#define                 AT91_ADC_STARTUP_(x)    ((x) << 16)
  60#define         AT91_ADC_SHTIM          (0xf  << 24)    /* Sample & Hold Time */
  61#define                 AT91_ADC_SHTIM_(x)      ((x) << 24)
  62#define         AT91_ADC_PENDBC         (0x0f << 28)    /* Pen Debounce time */
  63#define                 AT91_ADC_PENDBC_(x)     ((x) << 28)
  64
  65#define AT91_ADC_TSR            0x0C
  66#define         AT91_ADC_TSR_SHTIM      (0xf  << 24)    /* Sample & Hold Time */
  67#define                 AT91_ADC_TSR_SHTIM_(x)  ((x) << 24)
  68
  69#define AT91_ADC_CHER           0x10            /* Channel Enable Register */
  70#define AT91_ADC_CHDR           0x14            /* Channel Disable Register */
  71#define AT91_ADC_CHSR           0x18            /* Channel Status Register */
  72#define         AT91_ADC_CH(n)          (1 << (n))      /* Channel Number */
  73
  74#define AT91_ADC_SR             0x1C            /* Status Register */
  75#define         AT91_ADC_EOC(n)         (1 << (n))      /* End of Conversion on Channel N */
  76#define         AT91_ADC_OVRE(n)        (1 << ((n) + 8))/* Overrun Error on Channel N */
  77#define         AT91_ADC_DRDY           (1 << 16)       /* Data Ready */
  78#define         AT91_ADC_GOVRE          (1 << 17)       /* General Overrun Error */
  79#define         AT91_ADC_ENDRX          (1 << 18)       /* End of RX Buffer */
  80#define         AT91_ADC_RXFUFF         (1 << 19)       /* RX Buffer Full */
  81
  82#define AT91_ADC_SR_9X5         0x30            /* Status Register for 9x5 */
  83#define         AT91_ADC_SR_DRDY_9X5    (1 << 24)       /* Data Ready */
  84
  85#define AT91_ADC_LCDR           0x20            /* Last Converted Data Register */
  86#define         AT91_ADC_LDATA          (0x3ff)
  87
  88#define AT91_ADC_IER            0x24            /* Interrupt Enable Register */
  89#define AT91_ADC_IDR            0x28            /* Interrupt Disable Register */
  90#define AT91_ADC_IMR            0x2C            /* Interrupt Mask Register */
  91#define         AT91RL_ADC_IER_PEN      (1 << 20)
  92#define         AT91RL_ADC_IER_NOPEN    (1 << 21)
  93#define         AT91_ADC_IER_PEN        (1 << 29)
  94#define         AT91_ADC_IER_NOPEN      (1 << 30)
  95#define         AT91_ADC_IER_XRDY       (1 << 20)
  96#define         AT91_ADC_IER_YRDY       (1 << 21)
  97#define         AT91_ADC_IER_PRDY       (1 << 22)
  98#define         AT91_ADC_ISR_PENS       (1 << 31)
  99
 100#define AT91_ADC_CHR(n)         (0x30 + ((n) * 4))      /* Channel Data Register N */
 101#define         AT91_ADC_DATA           (0x3ff)
 102
 103#define AT91_ADC_CDR0_9X5       (0x50)                  /* Channel Data Register 0 for 9X5 */
 104
 105#define AT91_ADC_ACR            0x94    /* Analog Control Register */
 106#define         AT91_ADC_ACR_PENDETSENS (0x3 << 0)      /* pull-up resistor */
 107
 108#define AT91_ADC_TSMR           0xB0
 109#define         AT91_ADC_TSMR_TSMODE    (3 << 0)        /* Touch Screen Mode */
 110#define                 AT91_ADC_TSMR_TSMODE_NONE               (0 << 0)
 111#define                 AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS     (1 << 0)
 112#define                 AT91_ADC_TSMR_TSMODE_4WIRE_PRESS        (2 << 0)
 113#define                 AT91_ADC_TSMR_TSMODE_5WIRE              (3 << 0)
 114#define         AT91_ADC_TSMR_TSAV      (3 << 4)        /* Averages samples */
 115#define                 AT91_ADC_TSMR_TSAV_(x)          ((x) << 4)
 116#define         AT91_ADC_TSMR_SCTIM     (0x0f << 16)    /* Switch closure time */
 117#define                 AT91_ADC_TSMR_SCTIM_(x)         ((x) << 16)
 118#define         AT91_ADC_TSMR_PENDBC    (0x0f << 28)    /* Pen Debounce time */
 119#define                 AT91_ADC_TSMR_PENDBC_(x)        ((x) << 28)
 120#define         AT91_ADC_TSMR_NOTSDMA   (1 << 22)       /* No Touchscreen DMA */
 121#define         AT91_ADC_TSMR_PENDET_DIS        (0 << 24)       /* Pen contact detection disable */
 122#define         AT91_ADC_TSMR_PENDET_ENA        (1 << 24)       /* Pen contact detection enable */
 123
 124#define AT91_ADC_TSXPOSR        0xB4
 125#define AT91_ADC_TSYPOSR        0xB8
 126#define AT91_ADC_TSPRESSR       0xBC
 127
 128#define AT91_ADC_TRGR_9260      AT91_ADC_MR
 129#define AT91_ADC_TRGR_9G45      0x08
 130#define AT91_ADC_TRGR_9X5       0xC0
 131
 132/* Trigger Register bit field */
 133#define         AT91_ADC_TRGR_TRGPER    (0xffff << 16)
 134#define                 AT91_ADC_TRGR_TRGPER_(x)        ((x) << 16)
 135#define         AT91_ADC_TRGR_TRGMOD    (0x7 << 0)
 136#define                 AT91_ADC_TRGR_NONE              (0 << 0)
 137#define                 AT91_ADC_TRGR_MOD_PERIOD_TRIG   (5 << 0)
 138
 139#define AT91_ADC_CHAN(st, ch) \
 140        (st->registers->channel_base + (ch * 4))
 141#define at91_adc_readl(st, reg) \
 142        (readl_relaxed(st->reg_base + reg))
 143#define at91_adc_writel(st, reg, val) \
 144        (writel_relaxed(val, st->reg_base + reg))
 145
 146#define DRIVER_NAME             "at91_adc"
 147#define MAX_POS_BITS            12
 148
 149#define TOUCH_SAMPLE_PERIOD_US          2000    /* 2ms */
 150#define TOUCH_PEN_DETECT_DEBOUNCE_US    200
 151
 152#define MAX_RLPOS_BITS         10
 153#define TOUCH_SAMPLE_PERIOD_US_RL      10000   /* 10ms, the SoC can't keep up with 2ms */
 154#define TOUCH_SHTIM                    0xa
 155#define TOUCH_SCTIM_US          10              /* 10us for the Touchscreen Switches Closure Time */
 156
 157/**
 158 * struct at91_adc_reg_desc - Various informations relative to registers
 159 * @channel_base:       Base offset for the channel data registers
 160 * @drdy_mask:          Mask of the DRDY field in the relevant registers
 161                        (Interruptions registers mostly)
 162 * @status_register:    Offset of the Interrupt Status Register
 163 * @trigger_register:   Offset of the Trigger setup register
 164 * @mr_prescal_mask:    Mask of the PRESCAL field in the adc MR register
 165 * @mr_startup_mask:    Mask of the STARTUP field in the adc MR register
 166 */
 167struct at91_adc_reg_desc {
 168        u8      channel_base;
 169        u32     drdy_mask;
 170        u8      status_register;
 171        u8      trigger_register;
 172        u32     mr_prescal_mask;
 173        u32     mr_startup_mask;
 174};
 175
 176struct at91_adc_caps {
 177        bool    has_ts;         /* Support touch screen */
 178        bool    has_tsmr;       /* only at91sam9x5, sama5d3 have TSMR reg */
 179        /*
 180         * Numbers of sampling data will be averaged. Can be 0~3.
 181         * Hardware can average (2 ^ ts_filter_average) sample data.
 182         */
 183        u8      ts_filter_average;
 184        /* Pen Detection input pull-up resistor, can be 0~3 */
 185        u8      ts_pen_detect_sensitivity;
 186
 187        /* startup time calculate function */
 188        u32 (*calc_startup_ticks)(u32 startup_time, u32 adc_clk_khz);
 189
 190        u8      num_channels;
 191        struct at91_adc_reg_desc registers;
 192};
 193
 194struct at91_adc_state {
 195        struct clk              *adc_clk;
 196        u16                     *buffer;
 197        unsigned long           channels_mask;
 198        struct clk              *clk;
 199        bool                    done;
 200        int                     irq;
 201        u16                     last_value;
 202        int                     chnb;
 203        struct mutex            lock;
 204        u8                      num_channels;
 205        void __iomem            *reg_base;
 206        struct at91_adc_reg_desc *registers;
 207        u32                     startup_time;
 208        u8                      sample_hold_time;
 209        bool                    sleep_mode;
 210        struct iio_trigger      **trig;
 211        struct at91_adc_trigger *trigger_list;
 212        u32                     trigger_number;
 213        bool                    use_external;
 214        u32                     vref_mv;
 215        u32                     res;            /* resolution used for convertions */
 216        bool                    low_res;        /* the resolution corresponds to the lowest one */
 217        wait_queue_head_t       wq_data_avail;
 218        struct at91_adc_caps    *caps;
 219
 220        /*
 221         * Following ADC channels are shared by touchscreen:
 222         *
 223         * CH0 -- Touch screen XP/UL
 224         * CH1 -- Touch screen XM/UR
 225         * CH2 -- Touch screen YP/LL
 226         * CH3 -- Touch screen YM/Sense
 227         * CH4 -- Touch screen LR(5-wire only)
 228         *
 229         * The bitfields below represents the reserved channel in the
 230         * touchscreen mode.
 231         */
 232#define CHAN_MASK_TOUCHSCREEN_4WIRE     (0xf << 0)
 233#define CHAN_MASK_TOUCHSCREEN_5WIRE     (0x1f << 0)
 234        enum atmel_adc_ts_type  touchscreen_type;
 235        struct input_dev        *ts_input;
 236
 237        u16                     ts_sample_period_val;
 238        u32                     ts_pressure_threshold;
 239        u16                     ts_pendbc;
 240
 241        bool                    ts_bufferedmeasure;
 242        u32                     ts_prev_absx;
 243        u32                     ts_prev_absy;
 244};
 245
 246static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
 247{
 248        struct iio_poll_func *pf = p;
 249        struct iio_dev *idev = pf->indio_dev;
 250        struct at91_adc_state *st = iio_priv(idev);
 251        int i, j = 0;
 252
 253        for (i = 0; i < idev->masklength; i++) {
 254                if (!test_bit(i, idev->active_scan_mask))
 255                        continue;
 256                st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, i));
 257                j++;
 258        }
 259
 260        iio_push_to_buffers_with_timestamp(idev, st->buffer, pf->timestamp);
 261
 262        iio_trigger_notify_done(idev->trig);
 263
 264        /* Needed to ACK the DRDY interruption */
 265        at91_adc_readl(st, AT91_ADC_LCDR);
 266
 267        enable_irq(st->irq);
 268
 269        return IRQ_HANDLED;
 270}
 271
 272/* Handler for classic adc channel eoc trigger */
 273static void handle_adc_eoc_trigger(int irq, struct iio_dev *idev)
 274{
 275        struct at91_adc_state *st = iio_priv(idev);
 276
 277        if (iio_buffer_enabled(idev)) {
 278                disable_irq_nosync(irq);
 279                iio_trigger_poll(idev->trig);
 280        } else {
 281                st->last_value = at91_adc_readl(st, AT91_ADC_CHAN(st, st->chnb));
 282                st->done = true;
 283                wake_up_interruptible(&st->wq_data_avail);
 284        }
 285}
 286
 287static int at91_ts_sample(struct at91_adc_state *st)
 288{
 289        unsigned int xscale, yscale, reg, z1, z2;
 290        unsigned int x, y, pres, xpos, ypos;
 291        unsigned int rxp = 1;
 292        unsigned int factor = 1000;
 293        struct iio_dev *idev = iio_priv_to_dev(st);
 294
 295        unsigned int xyz_mask_bits = st->res;
 296        unsigned int xyz_mask = (1 << xyz_mask_bits) - 1;
 297
 298        /* calculate position */
 299        /* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */
 300        reg = at91_adc_readl(st, AT91_ADC_TSXPOSR);
 301        xpos = reg & xyz_mask;
 302        x = (xpos << MAX_POS_BITS) - xpos;
 303        xscale = (reg >> 16) & xyz_mask;
 304        if (xscale == 0) {
 305                dev_err(&idev->dev, "Error: xscale == 0!\n");
 306                return -1;
 307        }
 308        x /= xscale;
 309
 310        /* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */
 311        reg = at91_adc_readl(st, AT91_ADC_TSYPOSR);
 312        ypos = reg & xyz_mask;
 313        y = (ypos << MAX_POS_BITS) - ypos;
 314        yscale = (reg >> 16) & xyz_mask;
 315        if (yscale == 0) {
 316                dev_err(&idev->dev, "Error: yscale == 0!\n");
 317                return -1;
 318        }
 319        y /= yscale;
 320
 321        /* calculate the pressure */
 322        reg = at91_adc_readl(st, AT91_ADC_TSPRESSR);
 323        z1 = reg & xyz_mask;
 324        z2 = (reg >> 16) & xyz_mask;
 325
 326        if (z1 != 0)
 327                pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor)
 328                        / factor;
 329        else
 330                pres = st->ts_pressure_threshold;       /* no pen contacted */
 331
 332        dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n",
 333                                xpos, xscale, ypos, yscale, z1, z2, pres);
 334
 335        if (pres < st->ts_pressure_threshold) {
 336                dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n",
 337                                        x, y, pres / factor);
 338                input_report_abs(st->ts_input, ABS_X, x);
 339                input_report_abs(st->ts_input, ABS_Y, y);
 340                input_report_abs(st->ts_input, ABS_PRESSURE, pres);
 341                input_report_key(st->ts_input, BTN_TOUCH, 1);
 342                input_sync(st->ts_input);
 343        } else {
 344                dev_dbg(&idev->dev, "pressure too low: not reporting\n");
 345        }
 346
 347        return 0;
 348}
 349
 350static irqreturn_t at91_adc_rl_interrupt(int irq, void *private)
 351{
 352        struct iio_dev *idev = private;
 353        struct at91_adc_state *st = iio_priv(idev);
 354        u32 status = at91_adc_readl(st, st->registers->status_register);
 355        unsigned int reg;
 356
 357        status &= at91_adc_readl(st, AT91_ADC_IMR);
 358        if (status & GENMASK(st->num_channels - 1, 0))
 359                handle_adc_eoc_trigger(irq, idev);
 360
 361        if (status & AT91RL_ADC_IER_PEN) {
 362                /* Disabling pen debounce is required to get a NOPEN irq */
 363                reg = at91_adc_readl(st, AT91_ADC_MR);
 364                reg &= ~AT91_ADC_PENDBC;
 365                at91_adc_writel(st, AT91_ADC_MR, reg);
 366
 367                at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
 368                at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_NOPEN
 369                                | AT91_ADC_EOC(3));
 370                /* Set up period trigger for sampling */
 371                at91_adc_writel(st, st->registers->trigger_register,
 372                        AT91_ADC_TRGR_MOD_PERIOD_TRIG |
 373                        AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
 374        } else if (status & AT91RL_ADC_IER_NOPEN) {
 375                reg = at91_adc_readl(st, AT91_ADC_MR);
 376                reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
 377                at91_adc_writel(st, AT91_ADC_MR, reg);
 378                at91_adc_writel(st, st->registers->trigger_register,
 379                        AT91_ADC_TRGR_NONE);
 380
 381                at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_NOPEN
 382                                | AT91_ADC_EOC(3));
 383                at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
 384                st->ts_bufferedmeasure = false;
 385                input_report_key(st->ts_input, BTN_TOUCH, 0);
 386                input_sync(st->ts_input);
 387        } else if (status & AT91_ADC_EOC(3) && st->ts_input) {
 388                /* Conversion finished and we've a touchscreen */
 389                if (st->ts_bufferedmeasure) {
 390                        /*
 391                         * Last measurement is always discarded, since it can
 392                         * be erroneous.
 393                         * Always report previous measurement
 394                         */
 395                        input_report_abs(st->ts_input, ABS_X, st->ts_prev_absx);
 396                        input_report_abs(st->ts_input, ABS_Y, st->ts_prev_absy);
 397                        input_report_key(st->ts_input, BTN_TOUCH, 1);
 398                        input_sync(st->ts_input);
 399                } else
 400                        st->ts_bufferedmeasure = true;
 401
 402                /* Now make new measurement */
 403                st->ts_prev_absx = at91_adc_readl(st, AT91_ADC_CHAN(st, 3))
 404                                   << MAX_RLPOS_BITS;
 405                st->ts_prev_absx /= at91_adc_readl(st, AT91_ADC_CHAN(st, 2));
 406
 407                st->ts_prev_absy = at91_adc_readl(st, AT91_ADC_CHAN(st, 1))
 408                                   << MAX_RLPOS_BITS;
 409                st->ts_prev_absy /= at91_adc_readl(st, AT91_ADC_CHAN(st, 0));
 410        }
 411
 412        return IRQ_HANDLED;
 413}
 414
 415static irqreturn_t at91_adc_9x5_interrupt(int irq, void *private)
 416{
 417        struct iio_dev *idev = private;
 418        struct at91_adc_state *st = iio_priv(idev);
 419        u32 status = at91_adc_readl(st, st->registers->status_register);
 420        const uint32_t ts_data_irq_mask =
 421                AT91_ADC_IER_XRDY |
 422                AT91_ADC_IER_YRDY |
 423                AT91_ADC_IER_PRDY;
 424
 425        if (status & GENMASK(st->num_channels - 1, 0))
 426                handle_adc_eoc_trigger(irq, idev);
 427
 428        if (status & AT91_ADC_IER_PEN) {
 429                at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
 430                at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN |
 431                        ts_data_irq_mask);
 432                /* Set up period trigger for sampling */
 433                at91_adc_writel(st, st->registers->trigger_register,
 434                        AT91_ADC_TRGR_MOD_PERIOD_TRIG |
 435                        AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
 436        } else if (status & AT91_ADC_IER_NOPEN) {
 437                at91_adc_writel(st, st->registers->trigger_register, 0);
 438                at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN |
 439                        ts_data_irq_mask);
 440                at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
 441
 442                input_report_key(st->ts_input, BTN_TOUCH, 0);
 443                input_sync(st->ts_input);
 444        } else if ((status & ts_data_irq_mask) == ts_data_irq_mask) {
 445                /* Now all touchscreen data is ready */
 446
 447                if (status & AT91_ADC_ISR_PENS) {
 448                        /* validate data by pen contact */
 449                        at91_ts_sample(st);
 450                } else {
 451                        /* triggered by event that is no pen contact, just read
 452                         * them to clean the interrupt and discard all.
 453                         */
 454                        at91_adc_readl(st, AT91_ADC_TSXPOSR);
 455                        at91_adc_readl(st, AT91_ADC_TSYPOSR);
 456                        at91_adc_readl(st, AT91_ADC_TSPRESSR);
 457                }
 458        }
 459
 460        return IRQ_HANDLED;
 461}
 462
 463static int at91_adc_channel_init(struct iio_dev *idev)
 464{
 465        struct at91_adc_state *st = iio_priv(idev);
 466        struct iio_chan_spec *chan_array, *timestamp;
 467        int bit, idx = 0;
 468        unsigned long rsvd_mask = 0;
 469
 470        /* If touchscreen is enable, then reserve the adc channels */
 471        if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
 472                rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE;
 473        else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE)
 474                rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE;
 475
 476        /* set up the channel mask to reserve touchscreen channels */
 477        st->channels_mask &= ~rsvd_mask;
 478
 479        idev->num_channels = bitmap_weight(&st->channels_mask,
 480                                           st->num_channels) + 1;
 481
 482        chan_array = devm_kzalloc(&idev->dev,
 483                                  ((idev->num_channels + 1) *
 484                                        sizeof(struct iio_chan_spec)),
 485                                  GFP_KERNEL);
 486
 487        if (!chan_array)
 488                return -ENOMEM;
 489
 490        for_each_set_bit(bit, &st->channels_mask, st->num_channels) {
 491                struct iio_chan_spec *chan = chan_array + idx;
 492
 493                chan->type = IIO_VOLTAGE;
 494                chan->indexed = 1;
 495                chan->channel = bit;
 496                chan->scan_index = idx;
 497                chan->scan_type.sign = 'u';
 498                chan->scan_type.realbits = st->res;
 499                chan->scan_type.storagebits = 16;
 500                chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
 501                chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
 502                idx++;
 503        }
 504        timestamp = chan_array + idx;
 505
 506        timestamp->type = IIO_TIMESTAMP;
 507        timestamp->channel = -1;
 508        timestamp->scan_index = idx;
 509        timestamp->scan_type.sign = 's';
 510        timestamp->scan_type.realbits = 64;
 511        timestamp->scan_type.storagebits = 64;
 512
 513        idev->channels = chan_array;
 514        return idev->num_channels;
 515}
 516
 517static int at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
 518                                             struct at91_adc_trigger *triggers,
 519                                             const char *trigger_name)
 520{
 521        struct at91_adc_state *st = iio_priv(idev);
 522        int i;
 523
 524        for (i = 0; i < st->trigger_number; i++) {
 525                char *name = kasprintf(GFP_KERNEL,
 526                                "%s-dev%d-%s",
 527                                idev->name,
 528                                idev->id,
 529                                triggers[i].name);
 530                if (!name)
 531                        return -ENOMEM;
 532
 533                if (strcmp(trigger_name, name) == 0) {
 534                        kfree(name);
 535                        if (triggers[i].value == 0)
 536                                return -EINVAL;
 537                        return triggers[i].value;
 538                }
 539
 540                kfree(name);
 541        }
 542
 543        return -EINVAL;
 544}
 545
 546static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
 547{
 548        struct iio_dev *idev = iio_trigger_get_drvdata(trig);
 549        struct at91_adc_state *st = iio_priv(idev);
 550        struct at91_adc_reg_desc *reg = st->registers;
 551        u32 status = at91_adc_readl(st, reg->trigger_register);
 552        int value;
 553        u8 bit;
 554
 555        value = at91_adc_get_trigger_value_by_name(idev,
 556                                                   st->trigger_list,
 557                                                   idev->trig->name);
 558        if (value < 0)
 559                return value;
 560
 561        if (state) {
 562                st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
 563                if (st->buffer == NULL)
 564                        return -ENOMEM;
 565
 566                at91_adc_writel(st, reg->trigger_register,
 567                                status | value);
 568
 569                for_each_set_bit(bit, idev->active_scan_mask,
 570                                 st->num_channels) {
 571                        struct iio_chan_spec const *chan = idev->channels + bit;
 572                        at91_adc_writel(st, AT91_ADC_CHER,
 573                                        AT91_ADC_CH(chan->channel));
 574                }
 575
 576                at91_adc_writel(st, AT91_ADC_IER, reg->drdy_mask);
 577
 578        } else {
 579                at91_adc_writel(st, AT91_ADC_IDR, reg->drdy_mask);
 580
 581                at91_adc_writel(st, reg->trigger_register,
 582                                status & ~value);
 583
 584                for_each_set_bit(bit, idev->active_scan_mask,
 585                                 st->num_channels) {
 586                        struct iio_chan_spec const *chan = idev->channels + bit;
 587                        at91_adc_writel(st, AT91_ADC_CHDR,
 588                                        AT91_ADC_CH(chan->channel));
 589                }
 590                kfree(st->buffer);
 591        }
 592
 593        return 0;
 594}
 595
 596static const struct iio_trigger_ops at91_adc_trigger_ops = {
 597        .owner = THIS_MODULE,
 598        .set_trigger_state = &at91_adc_configure_trigger,
 599};
 600
 601static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
 602                                                     struct at91_adc_trigger *trigger)
 603{
 604        struct iio_trigger *trig;
 605        int ret;
 606
 607        trig = iio_trigger_alloc("%s-dev%d-%s", idev->name,
 608                                 idev->id, trigger->name);
 609        if (trig == NULL)
 610                return NULL;
 611
 612        trig->dev.parent = idev->dev.parent;
 613        iio_trigger_set_drvdata(trig, idev);
 614        trig->ops = &at91_adc_trigger_ops;
 615
 616        ret = iio_trigger_register(trig);
 617        if (ret)
 618                return NULL;
 619
 620        return trig;
 621}
 622
 623static int at91_adc_trigger_init(struct iio_dev *idev)
 624{
 625        struct at91_adc_state *st = iio_priv(idev);
 626        int i, ret;
 627
 628        st->trig = devm_kzalloc(&idev->dev,
 629                                st->trigger_number * sizeof(*st->trig),
 630                                GFP_KERNEL);
 631
 632        if (st->trig == NULL) {
 633                ret = -ENOMEM;
 634                goto error_ret;
 635        }
 636
 637        for (i = 0; i < st->trigger_number; i++) {
 638                if (st->trigger_list[i].is_external && !(st->use_external))
 639                        continue;
 640
 641                st->trig[i] = at91_adc_allocate_trigger(idev,
 642                                                        st->trigger_list + i);
 643                if (st->trig[i] == NULL) {
 644                        dev_err(&idev->dev,
 645                                "Could not allocate trigger %d\n", i);
 646                        ret = -ENOMEM;
 647                        goto error_trigger;
 648                }
 649        }
 650
 651        return 0;
 652
 653error_trigger:
 654        for (i--; i >= 0; i--) {
 655                iio_trigger_unregister(st->trig[i]);
 656                iio_trigger_free(st->trig[i]);
 657        }
 658error_ret:
 659        return ret;
 660}
 661
 662static void at91_adc_trigger_remove(struct iio_dev *idev)
 663{
 664        struct at91_adc_state *st = iio_priv(idev);
 665        int i;
 666
 667        for (i = 0; i < st->trigger_number; i++) {
 668                iio_trigger_unregister(st->trig[i]);
 669                iio_trigger_free(st->trig[i]);
 670        }
 671}
 672
 673static int at91_adc_buffer_init(struct iio_dev *idev)
 674{
 675        return iio_triggered_buffer_setup(idev, &iio_pollfunc_store_time,
 676                &at91_adc_trigger_handler, NULL);
 677}
 678
 679static void at91_adc_buffer_remove(struct iio_dev *idev)
 680{
 681        iio_triggered_buffer_cleanup(idev);
 682}
 683
 684static int at91_adc_read_raw(struct iio_dev *idev,
 685                             struct iio_chan_spec const *chan,
 686                             int *val, int *val2, long mask)
 687{
 688        struct at91_adc_state *st = iio_priv(idev);
 689        int ret;
 690
 691        switch (mask) {
 692        case IIO_CHAN_INFO_RAW:
 693                mutex_lock(&st->lock);
 694
 695                st->chnb = chan->channel;
 696                at91_adc_writel(st, AT91_ADC_CHER,
 697                                AT91_ADC_CH(chan->channel));
 698                at91_adc_writel(st, AT91_ADC_IER, BIT(chan->channel));
 699                at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_START);
 700
 701                ret = wait_event_interruptible_timeout(st->wq_data_avail,
 702                                                       st->done,
 703                                                       msecs_to_jiffies(1000));
 704                if (ret == 0)
 705                        ret = -ETIMEDOUT;
 706                if (ret < 0) {
 707                        mutex_unlock(&st->lock);
 708                        return ret;
 709                }
 710
 711                *val = st->last_value;
 712
 713                at91_adc_writel(st, AT91_ADC_CHDR,
 714                                AT91_ADC_CH(chan->channel));
 715                at91_adc_writel(st, AT91_ADC_IDR, BIT(chan->channel));
 716
 717                st->last_value = 0;
 718                st->done = false;
 719                mutex_unlock(&st->lock);
 720                return IIO_VAL_INT;
 721
 722        case IIO_CHAN_INFO_SCALE:
 723                *val = st->vref_mv;
 724                *val2 = chan->scan_type.realbits;
 725                return IIO_VAL_FRACTIONAL_LOG2;
 726        default:
 727                break;
 728        }
 729        return -EINVAL;
 730}
 731
 732static int at91_adc_of_get_resolution(struct at91_adc_state *st,
 733                                      struct platform_device *pdev)
 734{
 735        struct iio_dev *idev = iio_priv_to_dev(st);
 736        struct device_node *np = pdev->dev.of_node;
 737        int count, i, ret = 0;
 738        char *res_name, *s;
 739        u32 *resolutions;
 740
 741        count = of_property_count_strings(np, "atmel,adc-res-names");
 742        if (count < 2) {
 743                dev_err(&idev->dev, "You must specified at least two resolution names for "
 744                                    "adc-res-names property in the DT\n");
 745                return count;
 746        }
 747
 748        resolutions = kmalloc_array(count, sizeof(*resolutions), GFP_KERNEL);
 749        if (!resolutions)
 750                return -ENOMEM;
 751
 752        if (of_property_read_u32_array(np, "atmel,adc-res", resolutions, count)) {
 753                dev_err(&idev->dev, "Missing adc-res property in the DT.\n");
 754                ret = -ENODEV;
 755                goto ret;
 756        }
 757
 758        if (of_property_read_string(np, "atmel,adc-use-res", (const char **)&res_name))
 759                res_name = "highres";
 760
 761        for (i = 0; i < count; i++) {
 762                if (of_property_read_string_index(np, "atmel,adc-res-names", i, (const char **)&s))
 763                        continue;
 764
 765                if (strcmp(res_name, s))
 766                        continue;
 767
 768                st->res = resolutions[i];
 769                if (!strcmp(res_name, "lowres"))
 770                        st->low_res = true;
 771                else
 772                        st->low_res = false;
 773
 774                dev_info(&idev->dev, "Resolution used: %u bits\n", st->res);
 775                goto ret;
 776        }
 777
 778        dev_err(&idev->dev, "There is no resolution for %s\n", res_name);
 779
 780ret:
 781        kfree(resolutions);
 782        return ret;
 783}
 784
 785static u32 calc_startup_ticks_9260(u32 startup_time, u32 adc_clk_khz)
 786{
 787        /*
 788         * Number of ticks needed to cover the startup time of the ADC
 789         * as defined in the electrical characteristics of the board,
 790         * divided by 8. The formula thus is :
 791         *   Startup Time = (ticks + 1) * 8 / ADC Clock
 792         */
 793        return round_up((startup_time * adc_clk_khz / 1000) - 1, 8) / 8;
 794}
 795
 796static u32 calc_startup_ticks_9x5(u32 startup_time, u32 adc_clk_khz)
 797{
 798        /*
 799         * For sama5d3x and at91sam9x5, the formula changes to:
 800         * Startup Time = <lookup_table_value> / ADC Clock
 801         */
 802        const int startup_lookup[] = {
 803                0,   8,   16,  24,
 804                64,  80,  96,  112,
 805                512, 576, 640, 704,
 806                768, 832, 896, 960
 807                };
 808        int i, size = ARRAY_SIZE(startup_lookup);
 809        unsigned int ticks;
 810
 811        ticks = startup_time * adc_clk_khz / 1000;
 812        for (i = 0; i < size; i++)
 813                if (ticks < startup_lookup[i])
 814                        break;
 815
 816        ticks = i;
 817        if (ticks == size)
 818                /* Reach the end of lookup table */
 819                ticks = size - 1;
 820
 821        return ticks;
 822}
 823
 824static const struct of_device_id at91_adc_dt_ids[];
 825
 826static int at91_adc_probe_dt_ts(struct device_node *node,
 827        struct at91_adc_state *st, struct device *dev)
 828{
 829        int ret;
 830        u32 prop;
 831
 832        ret = of_property_read_u32(node, "atmel,adc-ts-wires", &prop);
 833        if (ret) {
 834                dev_info(dev, "ADC Touch screen is disabled.\n");
 835                return 0;
 836        }
 837
 838        switch (prop) {
 839        case 4:
 840        case 5:
 841                st->touchscreen_type = prop;
 842                break;
 843        default:
 844                dev_err(dev, "Unsupported number of touchscreen wires (%d). Should be 4 or 5.\n", prop);
 845                return -EINVAL;
 846        }
 847
 848        if (!st->caps->has_tsmr)
 849                return 0;
 850        prop = 0;
 851        of_property_read_u32(node, "atmel,adc-ts-pressure-threshold", &prop);
 852        st->ts_pressure_threshold = prop;
 853        if (st->ts_pressure_threshold) {
 854                return 0;
 855        } else {
 856                dev_err(dev, "Invalid pressure threshold for the touchscreen\n");
 857                return -EINVAL;
 858        }
 859}
 860
 861static int at91_adc_probe_dt(struct at91_adc_state *st,
 862                             struct platform_device *pdev)
 863{
 864        struct iio_dev *idev = iio_priv_to_dev(st);
 865        struct device_node *node = pdev->dev.of_node;
 866        struct device_node *trig_node;
 867        int i = 0, ret;
 868        u32 prop;
 869
 870        if (!node)
 871                return -EINVAL;
 872
 873        st->caps = (struct at91_adc_caps *)
 874                of_match_device(at91_adc_dt_ids, &pdev->dev)->data;
 875
 876        st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
 877
 878        if (of_property_read_u32(node, "atmel,adc-channels-used", &prop)) {
 879                dev_err(&idev->dev, "Missing adc-channels-used property in the DT.\n");
 880                ret = -EINVAL;
 881                goto error_ret;
 882        }
 883        st->channels_mask = prop;
 884
 885        st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
 886
 887        if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
 888                dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
 889                ret = -EINVAL;
 890                goto error_ret;
 891        }
 892        st->startup_time = prop;
 893
 894        prop = 0;
 895        of_property_read_u32(node, "atmel,adc-sample-hold-time", &prop);
 896        st->sample_hold_time = prop;
 897
 898        if (of_property_read_u32(node, "atmel,adc-vref", &prop)) {
 899                dev_err(&idev->dev, "Missing adc-vref property in the DT.\n");
 900                ret = -EINVAL;
 901                goto error_ret;
 902        }
 903        st->vref_mv = prop;
 904
 905        ret = at91_adc_of_get_resolution(st, pdev);
 906        if (ret)
 907                goto error_ret;
 908
 909        st->registers = &st->caps->registers;
 910        st->num_channels = st->caps->num_channels;
 911        st->trigger_number = of_get_child_count(node);
 912        st->trigger_list = devm_kzalloc(&idev->dev, st->trigger_number *
 913                                        sizeof(struct at91_adc_trigger),
 914                                        GFP_KERNEL);
 915        if (!st->trigger_list) {
 916                dev_err(&idev->dev, "Could not allocate trigger list memory.\n");
 917                ret = -ENOMEM;
 918                goto error_ret;
 919        }
 920
 921        for_each_child_of_node(node, trig_node) {
 922                struct at91_adc_trigger *trig = st->trigger_list + i;
 923                const char *name;
 924
 925                if (of_property_read_string(trig_node, "trigger-name", &name)) {
 926                        dev_err(&idev->dev, "Missing trigger-name property in the DT.\n");
 927                        ret = -EINVAL;
 928                        goto error_ret;
 929                }
 930                trig->name = name;
 931
 932                if (of_property_read_u32(trig_node, "trigger-value", &prop)) {
 933                        dev_err(&idev->dev, "Missing trigger-value property in the DT.\n");
 934                        ret = -EINVAL;
 935                        goto error_ret;
 936                }
 937                trig->value = prop;
 938                trig->is_external = of_property_read_bool(trig_node, "trigger-external");
 939                i++;
 940        }
 941
 942        /* Check if touchscreen is supported. */
 943        if (st->caps->has_ts)
 944                return at91_adc_probe_dt_ts(node, st, &idev->dev);
 945        else
 946                dev_info(&idev->dev, "not support touchscreen in the adc compatible string.\n");
 947
 948        return 0;
 949
 950error_ret:
 951        return ret;
 952}
 953
 954static int at91_adc_probe_pdata(struct at91_adc_state *st,
 955                                struct platform_device *pdev)
 956{
 957        struct at91_adc_data *pdata = pdev->dev.platform_data;
 958
 959        if (!pdata)
 960                return -EINVAL;
 961
 962        st->caps = (struct at91_adc_caps *)
 963                        platform_get_device_id(pdev)->driver_data;
 964
 965        st->use_external = pdata->use_external_triggers;
 966        st->vref_mv = pdata->vref;
 967        st->channels_mask = pdata->channels_used;
 968        st->num_channels = st->caps->num_channels;
 969        st->startup_time = pdata->startup_time;
 970        st->trigger_number = pdata->trigger_number;
 971        st->trigger_list = pdata->trigger_list;
 972        st->registers = &st->caps->registers;
 973        st->touchscreen_type = pdata->touchscreen_type;
 974
 975        return 0;
 976}
 977
 978static const struct iio_info at91_adc_info = {
 979        .driver_module = THIS_MODULE,
 980        .read_raw = &at91_adc_read_raw,
 981};
 982
 983/* Touchscreen related functions */
 984static int atmel_ts_open(struct input_dev *dev)
 985{
 986        struct at91_adc_state *st = input_get_drvdata(dev);
 987
 988        if (st->caps->has_tsmr)
 989                at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
 990        else
 991                at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
 992        return 0;
 993}
 994
 995static void atmel_ts_close(struct input_dev *dev)
 996{
 997        struct at91_adc_state *st = input_get_drvdata(dev);
 998
 999        if (st->caps->has_tsmr)
1000                at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
1001        else
1002                at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
1003}
1004
1005static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz)
1006{
1007        struct iio_dev *idev = iio_priv_to_dev(st);
1008        u32 reg = 0;
1009        u32 tssctim = 0;
1010        int i = 0;
1011
1012        /* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid
1013         * pen detect noise.
1014         * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock
1015         */
1016        st->ts_pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz /
1017                                 1000, 1);
1018
1019        while (st->ts_pendbc >> ++i)
1020                ;       /* Empty! Find the shift offset */
1021        if (abs(st->ts_pendbc - (1 << i)) < abs(st->ts_pendbc - (1 << (i - 1))))
1022                st->ts_pendbc = i;
1023        else
1024                st->ts_pendbc = i - 1;
1025
1026        if (!st->caps->has_tsmr) {
1027                reg = at91_adc_readl(st, AT91_ADC_MR);
1028                reg |= AT91_ADC_TSAMOD_TS_ONLY_MODE | AT91_ADC_PENDET;
1029
1030                reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
1031                at91_adc_writel(st, AT91_ADC_MR, reg);
1032
1033                reg = AT91_ADC_TSR_SHTIM_(TOUCH_SHTIM) & AT91_ADC_TSR_SHTIM;
1034                at91_adc_writel(st, AT91_ADC_TSR, reg);
1035
1036                st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US_RL *
1037                                                    adc_clk_khz / 1000) - 1, 1);
1038
1039                return 0;
1040        }
1041
1042        /* Touchscreen Switches Closure time needed for allowing the value to
1043         * stabilize.
1044         * Switch Closure Time = (TSSCTIM * 4) ADCClock periods
1045         */
1046        tssctim = DIV_ROUND_UP(TOUCH_SCTIM_US * adc_clk_khz / 1000, 4);
1047        dev_dbg(&idev->dev, "adc_clk at: %d KHz, tssctim at: %d\n",
1048                adc_clk_khz, tssctim);
1049
1050        if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
1051                reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
1052        else
1053                reg = AT91_ADC_TSMR_TSMODE_5WIRE;
1054
1055        reg |= AT91_ADC_TSMR_SCTIM_(tssctim) & AT91_ADC_TSMR_SCTIM;
1056        reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average)
1057               & AT91_ADC_TSMR_TSAV;
1058        reg |= AT91_ADC_TSMR_PENDBC_(st->ts_pendbc) & AT91_ADC_TSMR_PENDBC;
1059        reg |= AT91_ADC_TSMR_NOTSDMA;
1060        reg |= AT91_ADC_TSMR_PENDET_ENA;
1061        reg |= 0x03 << 8;       /* TSFREQ, needs to be bigger than TSAV */
1062
1063        at91_adc_writel(st, AT91_ADC_TSMR, reg);
1064
1065        /* Change adc internal resistor value for better pen detection,
1066         * default value is 100 kOhm.
1067         * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm
1068         * option only available on ES2 and higher
1069         */
1070        at91_adc_writel(st, AT91_ADC_ACR, st->caps->ts_pen_detect_sensitivity
1071                        & AT91_ADC_ACR_PENDETSENS);
1072
1073        /* Sample Period Time = (TRGPER + 1) / ADCClock */
1074        st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US *
1075                        adc_clk_khz / 1000) - 1, 1);
1076
1077        return 0;
1078}
1079
1080static int at91_ts_register(struct at91_adc_state *st,
1081                struct platform_device *pdev)
1082{
1083        struct input_dev *input;
1084        struct iio_dev *idev = iio_priv_to_dev(st);
1085        int ret;
1086
1087        input = input_allocate_device();
1088        if (!input) {
1089                dev_err(&idev->dev, "Failed to allocate TS device!\n");
1090                return -ENOMEM;
1091        }
1092
1093        input->name = DRIVER_NAME;
1094        input->id.bustype = BUS_HOST;
1095        input->dev.parent = &pdev->dev;
1096        input->open = atmel_ts_open;
1097        input->close = atmel_ts_close;
1098
1099        __set_bit(EV_ABS, input->evbit);
1100        __set_bit(EV_KEY, input->evbit);
1101        __set_bit(BTN_TOUCH, input->keybit);
1102        if (st->caps->has_tsmr) {
1103                input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1,
1104                                     0, 0);
1105                input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1,
1106                                     0, 0);
1107                input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0);
1108        } else {
1109                if (st->touchscreen_type != ATMEL_ADC_TOUCHSCREEN_4WIRE) {
1110                        dev_err(&pdev->dev,
1111                                "This touchscreen controller only support 4 wires\n");
1112                        ret = -EINVAL;
1113                        goto err;
1114                }
1115
1116                input_set_abs_params(input, ABS_X, 0, (1 << MAX_RLPOS_BITS) - 1,
1117                                     0, 0);
1118                input_set_abs_params(input, ABS_Y, 0, (1 << MAX_RLPOS_BITS) - 1,
1119                                     0, 0);
1120        }
1121
1122        st->ts_input = input;
1123        input_set_drvdata(input, st);
1124
1125        ret = input_register_device(input);
1126        if (ret)
1127                goto err;
1128
1129        return ret;
1130
1131err:
1132        input_free_device(st->ts_input);
1133        return ret;
1134}
1135
1136static void at91_ts_unregister(struct at91_adc_state *st)
1137{
1138        input_unregister_device(st->ts_input);
1139}
1140
1141static int at91_adc_probe(struct platform_device *pdev)
1142{
1143        unsigned int prsc, mstrclk, ticks, adc_clk, adc_clk_khz, shtim;
1144        int ret;
1145        struct iio_dev *idev;
1146        struct at91_adc_state *st;
1147        struct resource *res;
1148        u32 reg;
1149
1150        idev = devm_iio_device_alloc(&pdev->dev, sizeof(struct at91_adc_state));
1151        if (!idev)
1152                return -ENOMEM;
1153
1154        st = iio_priv(idev);
1155
1156        if (pdev->dev.of_node)
1157                ret = at91_adc_probe_dt(st, pdev);
1158        else
1159                ret = at91_adc_probe_pdata(st, pdev);
1160
1161        if (ret) {
1162                dev_err(&pdev->dev, "No platform data available.\n");
1163                return -EINVAL;
1164        }
1165
1166        platform_set_drvdata(pdev, idev);
1167
1168        idev->dev.parent = &pdev->dev;
1169        idev->name = dev_name(&pdev->dev);
1170        idev->modes = INDIO_DIRECT_MODE;
1171        idev->info = &at91_adc_info;
1172
1173        st->irq = platform_get_irq(pdev, 0);
1174        if (st->irq < 0) {
1175                dev_err(&pdev->dev, "No IRQ ID is designated\n");
1176                return -ENODEV;
1177        }
1178
1179        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1180
1181        st->reg_base = devm_ioremap_resource(&pdev->dev, res);
1182        if (IS_ERR(st->reg_base)) {
1183                return PTR_ERR(st->reg_base);
1184        }
1185
1186        /*
1187         * Disable all IRQs before setting up the handler
1188         */
1189        at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
1190        at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
1191
1192        if (st->caps->has_tsmr)
1193                ret = request_irq(st->irq, at91_adc_9x5_interrupt, 0,
1194                                  pdev->dev.driver->name, idev);
1195        else
1196                ret = request_irq(st->irq, at91_adc_rl_interrupt, 0,
1197                                  pdev->dev.driver->name, idev);
1198        if (ret) {
1199                dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
1200                return ret;
1201        }
1202
1203        st->clk = devm_clk_get(&pdev->dev, "adc_clk");
1204        if (IS_ERR(st->clk)) {
1205                dev_err(&pdev->dev, "Failed to get the clock.\n");
1206                ret = PTR_ERR(st->clk);
1207                goto error_free_irq;
1208        }
1209
1210        ret = clk_prepare_enable(st->clk);
1211        if (ret) {
1212                dev_err(&pdev->dev,
1213                        "Could not prepare or enable the clock.\n");
1214                goto error_free_irq;
1215        }
1216
1217        st->adc_clk = devm_clk_get(&pdev->dev, "adc_op_clk");
1218        if (IS_ERR(st->adc_clk)) {
1219                dev_err(&pdev->dev, "Failed to get the ADC clock.\n");
1220                ret = PTR_ERR(st->adc_clk);
1221                goto error_disable_clk;
1222        }
1223
1224        ret = clk_prepare_enable(st->adc_clk);
1225        if (ret) {
1226                dev_err(&pdev->dev,
1227                        "Could not prepare or enable the ADC clock.\n");
1228                goto error_disable_clk;
1229        }
1230
1231        /*
1232         * Prescaler rate computation using the formula from the Atmel's
1233         * datasheet : ADC Clock = MCK / ((Prescaler + 1) * 2), ADC Clock being
1234         * specified by the electrical characteristics of the board.
1235         */
1236        mstrclk = clk_get_rate(st->clk);
1237        adc_clk = clk_get_rate(st->adc_clk);
1238        adc_clk_khz = adc_clk / 1000;
1239
1240        dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n",
1241                mstrclk, adc_clk);
1242
1243        prsc = (mstrclk / (2 * adc_clk)) - 1;
1244
1245        if (!st->startup_time) {
1246                dev_err(&pdev->dev, "No startup time available.\n");
1247                ret = -EINVAL;
1248                goto error_disable_adc_clk;
1249        }
1250        ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
1251
1252        /*
1253         * a minimal Sample and Hold Time is necessary for the ADC to guarantee
1254         * the best converted final value between two channels selection
1255         * The formula thus is : Sample and Hold Time = (shtim + 1) / ADCClock
1256         */
1257        if (st->sample_hold_time > 0)
1258                shtim = round_up((st->sample_hold_time * adc_clk_khz / 1000)
1259                                 - 1, 1);
1260        else
1261                shtim = 0;
1262
1263        reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask;
1264        reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask;
1265        if (st->low_res)
1266                reg |= AT91_ADC_LOWRES;
1267        if (st->sleep_mode)
1268                reg |= AT91_ADC_SLEEP;
1269        reg |= AT91_ADC_SHTIM_(shtim) & AT91_ADC_SHTIM;
1270        at91_adc_writel(st, AT91_ADC_MR, reg);
1271
1272        /* Setup the ADC channels available on the board */
1273        ret = at91_adc_channel_init(idev);
1274        if (ret < 0) {
1275                dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
1276                goto error_disable_adc_clk;
1277        }
1278
1279        init_waitqueue_head(&st->wq_data_avail);
1280        mutex_init(&st->lock);
1281
1282        /*
1283         * Since touch screen will set trigger register as period trigger. So
1284         * when touch screen is enabled, then we have to disable hardware
1285         * trigger for classic adc.
1286         */
1287        if (!st->touchscreen_type) {
1288                ret = at91_adc_buffer_init(idev);
1289                if (ret < 0) {
1290                        dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
1291                        goto error_disable_adc_clk;
1292                }
1293
1294                ret = at91_adc_trigger_init(idev);
1295                if (ret < 0) {
1296                        dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
1297                        at91_adc_buffer_remove(idev);
1298                        goto error_disable_adc_clk;
1299                }
1300        } else {
1301                ret = at91_ts_register(st, pdev);
1302                if (ret)
1303                        goto error_disable_adc_clk;
1304
1305                at91_ts_hw_init(st, adc_clk_khz);
1306        }
1307
1308        ret = iio_device_register(idev);
1309        if (ret < 0) {
1310                dev_err(&pdev->dev, "Couldn't register the device.\n");
1311                goto error_iio_device_register;
1312        }
1313
1314        return 0;
1315
1316error_iio_device_register:
1317        if (!st->touchscreen_type) {
1318                at91_adc_trigger_remove(idev);
1319                at91_adc_buffer_remove(idev);
1320        } else {
1321                at91_ts_unregister(st);
1322        }
1323error_disable_adc_clk:
1324        clk_disable_unprepare(st->adc_clk);
1325error_disable_clk:
1326        clk_disable_unprepare(st->clk);
1327error_free_irq:
1328        free_irq(st->irq, idev);
1329        return ret;
1330}
1331
1332static int at91_adc_remove(struct platform_device *pdev)
1333{
1334        struct iio_dev *idev = platform_get_drvdata(pdev);
1335        struct at91_adc_state *st = iio_priv(idev);
1336
1337        iio_device_unregister(idev);
1338        if (!st->touchscreen_type) {
1339                at91_adc_trigger_remove(idev);
1340                at91_adc_buffer_remove(idev);
1341        } else {
1342                at91_ts_unregister(st);
1343        }
1344        clk_disable_unprepare(st->adc_clk);
1345        clk_disable_unprepare(st->clk);
1346        free_irq(st->irq, idev);
1347
1348        return 0;
1349}
1350
1351#ifdef CONFIG_PM_SLEEP
1352static int at91_adc_suspend(struct device *dev)
1353{
1354        struct iio_dev *idev = platform_get_drvdata(to_platform_device(dev));
1355        struct at91_adc_state *st = iio_priv(idev);
1356
1357        pinctrl_pm_select_sleep_state(dev);
1358        clk_disable_unprepare(st->clk);
1359
1360        return 0;
1361}
1362
1363static int at91_adc_resume(struct device *dev)
1364{
1365        struct iio_dev *idev = platform_get_drvdata(to_platform_device(dev));
1366        struct at91_adc_state *st = iio_priv(idev);
1367
1368        clk_prepare_enable(st->clk);
1369        pinctrl_pm_select_default_state(dev);
1370
1371        return 0;
1372}
1373#endif
1374
1375static SIMPLE_DEV_PM_OPS(at91_adc_pm_ops, at91_adc_suspend, at91_adc_resume);
1376
1377static struct at91_adc_caps at91sam9260_caps = {
1378        .calc_startup_ticks = calc_startup_ticks_9260,
1379        .num_channels = 4,
1380        .registers = {
1381                .channel_base = AT91_ADC_CHR(0),
1382                .drdy_mask = AT91_ADC_DRDY,
1383                .status_register = AT91_ADC_SR,
1384                .trigger_register = AT91_ADC_TRGR_9260,
1385                .mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1386                .mr_startup_mask = AT91_ADC_STARTUP_9260,
1387        },
1388};
1389
1390static struct at91_adc_caps at91sam9rl_caps = {
1391        .has_ts = true,
1392        .calc_startup_ticks = calc_startup_ticks_9260,  /* same as 9260 */
1393        .num_channels = 6,
1394        .registers = {
1395                .channel_base = AT91_ADC_CHR(0),
1396                .drdy_mask = AT91_ADC_DRDY,
1397                .status_register = AT91_ADC_SR,
1398                .trigger_register = AT91_ADC_TRGR_9G45,
1399                .mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1400                .mr_startup_mask = AT91_ADC_STARTUP_9G45,
1401        },
1402};
1403
1404static struct at91_adc_caps at91sam9g45_caps = {
1405        .has_ts = true,
1406        .calc_startup_ticks = calc_startup_ticks_9260,  /* same as 9260 */
1407        .num_channels = 8,
1408        .registers = {
1409                .channel_base = AT91_ADC_CHR(0),
1410                .drdy_mask = AT91_ADC_DRDY,
1411                .status_register = AT91_ADC_SR,
1412                .trigger_register = AT91_ADC_TRGR_9G45,
1413                .mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1414                .mr_startup_mask = AT91_ADC_STARTUP_9G45,
1415        },
1416};
1417
1418static struct at91_adc_caps at91sam9x5_caps = {
1419        .has_ts = true,
1420        .has_tsmr = true,
1421        .ts_filter_average = 3,
1422        .ts_pen_detect_sensitivity = 2,
1423        .calc_startup_ticks = calc_startup_ticks_9x5,
1424        .num_channels = 12,
1425        .registers = {
1426                .channel_base = AT91_ADC_CDR0_9X5,
1427                .drdy_mask = AT91_ADC_SR_DRDY_9X5,
1428                .status_register = AT91_ADC_SR_9X5,
1429                .trigger_register = AT91_ADC_TRGR_9X5,
1430                /* prescal mask is same as 9G45 */
1431                .mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1432                .mr_startup_mask = AT91_ADC_STARTUP_9X5,
1433        },
1434};
1435
1436static const struct of_device_id at91_adc_dt_ids[] = {
1437        { .compatible = "atmel,at91sam9260-adc", .data = &at91sam9260_caps },
1438        { .compatible = "atmel,at91sam9rl-adc", .data = &at91sam9rl_caps },
1439        { .compatible = "atmel,at91sam9g45-adc", .data = &at91sam9g45_caps },
1440        { .compatible = "atmel,at91sam9x5-adc", .data = &at91sam9x5_caps },
1441        {},
1442};
1443MODULE_DEVICE_TABLE(of, at91_adc_dt_ids);
1444
1445static const struct platform_device_id at91_adc_ids[] = {
1446        {
1447                .name = "at91sam9260-adc",
1448                .driver_data = (unsigned long)&at91sam9260_caps,
1449        }, {
1450                .name = "at91sam9rl-adc",
1451                .driver_data = (unsigned long)&at91sam9rl_caps,
1452        }, {
1453                .name = "at91sam9g45-adc",
1454                .driver_data = (unsigned long)&at91sam9g45_caps,
1455        }, {
1456                .name = "at91sam9x5-adc",
1457                .driver_data = (unsigned long)&at91sam9x5_caps,
1458        }, {
1459                /* terminator */
1460        }
1461};
1462MODULE_DEVICE_TABLE(platform, at91_adc_ids);
1463
1464static struct platform_driver at91_adc_driver = {
1465        .probe = at91_adc_probe,
1466        .remove = at91_adc_remove,
1467        .id_table = at91_adc_ids,
1468        .driver = {
1469                   .name = DRIVER_NAME,
1470                   .of_match_table = of_match_ptr(at91_adc_dt_ids),
1471                   .pm = &at91_adc_pm_ops,
1472        },
1473};
1474
1475module_platform_driver(at91_adc_driver);
1476
1477MODULE_LICENSE("GPL");
1478MODULE_DESCRIPTION("Atmel AT91 ADC Driver");
1479MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
1480