1fda8d26eSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2af300848SLars-Peter Clausen /* 3af300848SLars-Peter Clausen * Support code for Analog Devices Sigma-Delta ADCs 4af300848SLars-Peter Clausen * 5af300848SLars-Peter Clausen * Copyright 2012 Analog Devices Inc. 6af300848SLars-Peter Clausen * Author: Lars-Peter Clausen <lars@metafoo.de> 7af300848SLars-Peter Clausen */ 8af300848SLars-Peter Clausen 98bea9af8SLars-Peter Clausen #include <linux/align.h> 10af300848SLars-Peter Clausen #include <linux/interrupt.h> 11af300848SLars-Peter Clausen #include <linux/device.h> 12af300848SLars-Peter Clausen #include <linux/kernel.h> 13af300848SLars-Peter Clausen #include <linux/slab.h> 14af300848SLars-Peter Clausen #include <linux/spi/spi.h> 15af300848SLars-Peter Clausen #include <linux/err.h> 16af300848SLars-Peter Clausen #include <linux/module.h> 17af300848SLars-Peter Clausen 18af300848SLars-Peter Clausen #include <linux/iio/iio.h> 19af300848SLars-Peter Clausen #include <linux/iio/sysfs.h> 20af300848SLars-Peter Clausen #include <linux/iio/buffer.h> 21af300848SLars-Peter Clausen #include <linux/iio/trigger.h> 22af300848SLars-Peter Clausen #include <linux/iio/trigger_consumer.h> 23af300848SLars-Peter Clausen #include <linux/iio/triggered_buffer.h> 24af300848SLars-Peter Clausen #include <linux/iio/adc/ad_sigma_delta.h> 25af300848SLars-Peter Clausen 26af300848SLars-Peter Clausen #include <asm/unaligned.h> 27af300848SLars-Peter Clausen 28af300848SLars-Peter Clausen 29af300848SLars-Peter Clausen #define AD_SD_COMM_CHAN_MASK 0x3 30af300848SLars-Peter Clausen 31af300848SLars-Peter Clausen #define AD_SD_REG_COMM 0x00 32af300848SLars-Peter Clausen #define AD_SD_REG_DATA 0x03 33af300848SLars-Peter Clausen 34af300848SLars-Peter Clausen /** 35af300848SLars-Peter Clausen * ad_sd_set_comm() - Set communications register 36af300848SLars-Peter Clausen * 37af300848SLars-Peter Clausen * @sigma_delta: The sigma delta device 38af300848SLars-Peter Clausen * @comm: New value for the communications register 39af300848SLars-Peter Clausen */ 40af300848SLars-Peter Clausen void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm) 41af300848SLars-Peter Clausen { 42af300848SLars-Peter Clausen /* Some variants use the lower two bits of the communications register 43af300848SLars-Peter Clausen * to select the channel */ 44af300848SLars-Peter Clausen sigma_delta->comm = comm & AD_SD_COMM_CHAN_MASK; 45af300848SLars-Peter Clausen } 46ef807729SJonathan Cameron EXPORT_SYMBOL_NS_GPL(ad_sd_set_comm, IIO_AD_SIGMA_DELTA); 47af300848SLars-Peter Clausen 48af300848SLars-Peter Clausen /** 49af300848SLars-Peter Clausen * ad_sd_write_reg() - Write a register 50af300848SLars-Peter Clausen * 51af300848SLars-Peter Clausen * @sigma_delta: The sigma delta device 52af300848SLars-Peter Clausen * @reg: Address of the register 53af300848SLars-Peter Clausen * @size: Size of the register (0-3) 54af300848SLars-Peter Clausen * @val: Value to write to the register 55af300848SLars-Peter Clausen * 56af300848SLars-Peter Clausen * Returns 0 on success, an error code otherwise. 57af300848SLars-Peter Clausen **/ 58af300848SLars-Peter Clausen int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg, 59af300848SLars-Peter Clausen unsigned int size, unsigned int val) 60af300848SLars-Peter Clausen { 610fb6ee8dSLars-Peter Clausen uint8_t *data = sigma_delta->tx_buf; 62af300848SLars-Peter Clausen struct spi_transfer t = { 63af300848SLars-Peter Clausen .tx_buf = data, 64af300848SLars-Peter Clausen .len = size + 1, 65df1d80aeSLars-Peter Clausen .cs_change = sigma_delta->keep_cs_asserted, 66af300848SLars-Peter Clausen }; 67af300848SLars-Peter Clausen struct spi_message m; 68af300848SLars-Peter Clausen int ret; 69af300848SLars-Peter Clausen 70af300848SLars-Peter Clausen data[0] = (reg << sigma_delta->info->addr_shift) | sigma_delta->comm; 71af300848SLars-Peter Clausen 72af300848SLars-Peter Clausen switch (size) { 73af300848SLars-Peter Clausen case 3: 74c1909ab0SAndy Shevchenko put_unaligned_be24(val, &data[1]); 75af300848SLars-Peter Clausen break; 76af300848SLars-Peter Clausen case 2: 77af300848SLars-Peter Clausen put_unaligned_be16(val, &data[1]); 78af300848SLars-Peter Clausen break; 79af300848SLars-Peter Clausen case 1: 80af300848SLars-Peter Clausen data[1] = val; 81af300848SLars-Peter Clausen break; 82af300848SLars-Peter Clausen case 0: 83af300848SLars-Peter Clausen break; 84af300848SLars-Peter Clausen default: 85af300848SLars-Peter Clausen return -EINVAL; 86af300848SLars-Peter Clausen } 87af300848SLars-Peter Clausen 88af300848SLars-Peter Clausen spi_message_init(&m); 89af300848SLars-Peter Clausen spi_message_add_tail(&t, &m); 90af300848SLars-Peter Clausen 91af300848SLars-Peter Clausen if (sigma_delta->bus_locked) 92af300848SLars-Peter Clausen ret = spi_sync_locked(sigma_delta->spi, &m); 93af300848SLars-Peter Clausen else 94af300848SLars-Peter Clausen ret = spi_sync(sigma_delta->spi, &m); 95af300848SLars-Peter Clausen 96af300848SLars-Peter Clausen return ret; 97af300848SLars-Peter Clausen } 98ef807729SJonathan Cameron EXPORT_SYMBOL_NS_GPL(ad_sd_write_reg, IIO_AD_SIGMA_DELTA); 99af300848SLars-Peter Clausen 100af300848SLars-Peter Clausen static int ad_sd_read_reg_raw(struct ad_sigma_delta *sigma_delta, 101af300848SLars-Peter Clausen unsigned int reg, unsigned int size, uint8_t *val) 102af300848SLars-Peter Clausen { 1030fb6ee8dSLars-Peter Clausen uint8_t *data = sigma_delta->tx_buf; 104af300848SLars-Peter Clausen int ret; 105af300848SLars-Peter Clausen struct spi_transfer t[] = { 106af300848SLars-Peter Clausen { 107af300848SLars-Peter Clausen .tx_buf = data, 108af300848SLars-Peter Clausen .len = 1, 109af300848SLars-Peter Clausen }, { 110af300848SLars-Peter Clausen .rx_buf = val, 111af300848SLars-Peter Clausen .len = size, 112af300848SLars-Peter Clausen .cs_change = sigma_delta->bus_locked, 113af300848SLars-Peter Clausen }, 114af300848SLars-Peter Clausen }; 115af300848SLars-Peter Clausen struct spi_message m; 116af300848SLars-Peter Clausen 117af300848SLars-Peter Clausen spi_message_init(&m); 118af300848SLars-Peter Clausen 119af300848SLars-Peter Clausen if (sigma_delta->info->has_registers) { 120af300848SLars-Peter Clausen data[0] = reg << sigma_delta->info->addr_shift; 121af300848SLars-Peter Clausen data[0] |= sigma_delta->info->read_mask; 122fccfb9ceSDragos Bogdan data[0] |= sigma_delta->comm; 123af300848SLars-Peter Clausen spi_message_add_tail(&t[0], &m); 124af300848SLars-Peter Clausen } 125af300848SLars-Peter Clausen spi_message_add_tail(&t[1], &m); 126af300848SLars-Peter Clausen 127af300848SLars-Peter Clausen if (sigma_delta->bus_locked) 128af300848SLars-Peter Clausen ret = spi_sync_locked(sigma_delta->spi, &m); 129af300848SLars-Peter Clausen else 130af300848SLars-Peter Clausen ret = spi_sync(sigma_delta->spi, &m); 131af300848SLars-Peter Clausen 132af300848SLars-Peter Clausen return ret; 133af300848SLars-Peter Clausen } 134af300848SLars-Peter Clausen 135af300848SLars-Peter Clausen /** 136af300848SLars-Peter Clausen * ad_sd_read_reg() - Read a register 137af300848SLars-Peter Clausen * 138af300848SLars-Peter Clausen * @sigma_delta: The sigma delta device 139af300848SLars-Peter Clausen * @reg: Address of the register 140af300848SLars-Peter Clausen * @size: Size of the register (1-4) 141af300848SLars-Peter Clausen * @val: Read value 142af300848SLars-Peter Clausen * 143af300848SLars-Peter Clausen * Returns 0 on success, an error code otherwise. 144af300848SLars-Peter Clausen **/ 145af300848SLars-Peter Clausen int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, 146af300848SLars-Peter Clausen unsigned int reg, unsigned int size, unsigned int *val) 147af300848SLars-Peter Clausen { 148af300848SLars-Peter Clausen int ret; 149af300848SLars-Peter Clausen 1500fb6ee8dSLars-Peter Clausen ret = ad_sd_read_reg_raw(sigma_delta, reg, size, sigma_delta->rx_buf); 151af300848SLars-Peter Clausen if (ret < 0) 152af300848SLars-Peter Clausen goto out; 153af300848SLars-Peter Clausen 154af300848SLars-Peter Clausen switch (size) { 155af300848SLars-Peter Clausen case 4: 1560fb6ee8dSLars-Peter Clausen *val = get_unaligned_be32(sigma_delta->rx_buf); 157af300848SLars-Peter Clausen break; 158af300848SLars-Peter Clausen case 3: 1590fb6ee8dSLars-Peter Clausen *val = get_unaligned_be24(sigma_delta->rx_buf); 160af300848SLars-Peter Clausen break; 161af300848SLars-Peter Clausen case 2: 1620fb6ee8dSLars-Peter Clausen *val = get_unaligned_be16(sigma_delta->rx_buf); 163af300848SLars-Peter Clausen break; 164af300848SLars-Peter Clausen case 1: 1650fb6ee8dSLars-Peter Clausen *val = sigma_delta->rx_buf[0]; 166af300848SLars-Peter Clausen break; 167af300848SLars-Peter Clausen default: 168af300848SLars-Peter Clausen ret = -EINVAL; 169af300848SLars-Peter Clausen break; 170af300848SLars-Peter Clausen } 171af300848SLars-Peter Clausen 172af300848SLars-Peter Clausen out: 173af300848SLars-Peter Clausen return ret; 174af300848SLars-Peter Clausen } 175ef807729SJonathan Cameron EXPORT_SYMBOL_NS_GPL(ad_sd_read_reg, IIO_AD_SIGMA_DELTA); 176af300848SLars-Peter Clausen 1777fc10de8SDragos Bogdan /** 1787fc10de8SDragos Bogdan * ad_sd_reset() - Reset the serial interface 1797fc10de8SDragos Bogdan * 1807fc10de8SDragos Bogdan * @sigma_delta: The sigma delta device 1817fc10de8SDragos Bogdan * @reset_length: Number of SCLKs with DIN = 1 1827fc10de8SDragos Bogdan * 1837fc10de8SDragos Bogdan * Returns 0 on success, an error code otherwise. 1847fc10de8SDragos Bogdan **/ 1857fc10de8SDragos Bogdan int ad_sd_reset(struct ad_sigma_delta *sigma_delta, 1867fc10de8SDragos Bogdan unsigned int reset_length) 1877fc10de8SDragos Bogdan { 1887fc10de8SDragos Bogdan uint8_t *buf; 1897fc10de8SDragos Bogdan unsigned int size; 1907fc10de8SDragos Bogdan int ret; 1917fc10de8SDragos Bogdan 1927fc10de8SDragos Bogdan size = DIV_ROUND_UP(reset_length, 8); 1937fc10de8SDragos Bogdan buf = kcalloc(size, sizeof(*buf), GFP_KERNEL); 1947fc10de8SDragos Bogdan if (!buf) 1957fc10de8SDragos Bogdan return -ENOMEM; 1967fc10de8SDragos Bogdan 1977fc10de8SDragos Bogdan memset(buf, 0xff, size); 1987fc10de8SDragos Bogdan ret = spi_write(sigma_delta->spi, buf, size); 1997fc10de8SDragos Bogdan kfree(buf); 2007fc10de8SDragos Bogdan 2017fc10de8SDragos Bogdan return ret; 2027fc10de8SDragos Bogdan } 203ef807729SJonathan Cameron EXPORT_SYMBOL_NS_GPL(ad_sd_reset, IIO_AD_SIGMA_DELTA); 2047fc10de8SDragos Bogdan 205c88c8cd8SMircea Caprioru int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta, 206af300848SLars-Peter Clausen unsigned int mode, unsigned int channel) 207af300848SLars-Peter Clausen { 208af300848SLars-Peter Clausen int ret; 209cebc4585SNicholas Mc Guire unsigned long timeout; 210af300848SLars-Peter Clausen 211af300848SLars-Peter Clausen ret = ad_sigma_delta_set_channel(sigma_delta, channel); 212af300848SLars-Peter Clausen if (ret) 213af300848SLars-Peter Clausen return ret; 214af300848SLars-Peter Clausen 215af300848SLars-Peter Clausen spi_bus_lock(sigma_delta->spi->master); 216af300848SLars-Peter Clausen sigma_delta->bus_locked = true; 217df1d80aeSLars-Peter Clausen sigma_delta->keep_cs_asserted = true; 21816735d02SWolfram Sang reinit_completion(&sigma_delta->completion); 219af300848SLars-Peter Clausen 220af300848SLars-Peter Clausen ret = ad_sigma_delta_set_mode(sigma_delta, mode); 221af300848SLars-Peter Clausen if (ret < 0) 222af300848SLars-Peter Clausen goto out; 223af300848SLars-Peter Clausen 224af300848SLars-Peter Clausen sigma_delta->irq_dis = false; 225af300848SLars-Peter Clausen enable_irq(sigma_delta->spi->irq); 226cebc4585SNicholas Mc Guire timeout = wait_for_completion_timeout(&sigma_delta->completion, 2 * HZ); 227cebc4585SNicholas Mc Guire if (timeout == 0) { 228af300848SLars-Peter Clausen sigma_delta->irq_dis = true; 229af300848SLars-Peter Clausen disable_irq_nosync(sigma_delta->spi->irq); 230af300848SLars-Peter Clausen ret = -EIO; 231af300848SLars-Peter Clausen } else { 232af300848SLars-Peter Clausen ret = 0; 233af300848SLars-Peter Clausen } 234af300848SLars-Peter Clausen out: 235df1d80aeSLars-Peter Clausen sigma_delta->keep_cs_asserted = false; 236df1d80aeSLars-Peter Clausen ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); 237af300848SLars-Peter Clausen sigma_delta->bus_locked = false; 238af300848SLars-Peter Clausen spi_bus_unlock(sigma_delta->spi->master); 239af300848SLars-Peter Clausen 240af300848SLars-Peter Clausen return ret; 241af300848SLars-Peter Clausen } 242ef807729SJonathan Cameron EXPORT_SYMBOL_NS_GPL(ad_sd_calibrate, IIO_AD_SIGMA_DELTA); 243af300848SLars-Peter Clausen 244af300848SLars-Peter Clausen /** 245af300848SLars-Peter Clausen * ad_sd_calibrate_all() - Performs channel calibration 246af300848SLars-Peter Clausen * @sigma_delta: The sigma delta device 247af300848SLars-Peter Clausen * @cb: Array of channels and calibration type to perform 248af300848SLars-Peter Clausen * @n: Number of items in cb 249af300848SLars-Peter Clausen * 250af300848SLars-Peter Clausen * Returns 0 on success, an error code otherwise. 251af300848SLars-Peter Clausen **/ 252af300848SLars-Peter Clausen int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta, 253af300848SLars-Peter Clausen const struct ad_sd_calib_data *cb, unsigned int n) 254af300848SLars-Peter Clausen { 255af300848SLars-Peter Clausen unsigned int i; 256af300848SLars-Peter Clausen int ret; 257af300848SLars-Peter Clausen 258af300848SLars-Peter Clausen for (i = 0; i < n; i++) { 259af300848SLars-Peter Clausen ret = ad_sd_calibrate(sigma_delta, cb[i].mode, cb[i].channel); 260af300848SLars-Peter Clausen if (ret) 261af300848SLars-Peter Clausen return ret; 262af300848SLars-Peter Clausen } 263af300848SLars-Peter Clausen 264af300848SLars-Peter Clausen return 0; 265af300848SLars-Peter Clausen } 266ef807729SJonathan Cameron EXPORT_SYMBOL_NS_GPL(ad_sd_calibrate_all, IIO_AD_SIGMA_DELTA); 267af300848SLars-Peter Clausen 268af300848SLars-Peter Clausen /** 269af300848SLars-Peter Clausen * ad_sigma_delta_single_conversion() - Performs a single data conversion 270af300848SLars-Peter Clausen * @indio_dev: The IIO device 271af300848SLars-Peter Clausen * @chan: The conversion is done for this channel 272af300848SLars-Peter Clausen * @val: Pointer to the location where to store the read value 273af300848SLars-Peter Clausen * 274af300848SLars-Peter Clausen * Returns: 0 on success, an error value otherwise. 275af300848SLars-Peter Clausen */ 276af300848SLars-Peter Clausen int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev, 277af300848SLars-Peter Clausen const struct iio_chan_spec *chan, int *val) 278af300848SLars-Peter Clausen { 279af300848SLars-Peter Clausen struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 280af300848SLars-Peter Clausen unsigned int sample, raw_sample; 281f0aef2d0SLars-Peter Clausen unsigned int data_reg; 282af300848SLars-Peter Clausen int ret = 0; 283af300848SLars-Peter Clausen 28420228a1dSNuno Sá ret = iio_device_claim_direct_mode(indio_dev); 28520228a1dSNuno Sá if (ret) 28620228a1dSNuno Sá return ret; 287af300848SLars-Peter Clausen 288af300848SLars-Peter Clausen ad_sigma_delta_set_channel(sigma_delta, chan->address); 289af300848SLars-Peter Clausen 290af300848SLars-Peter Clausen spi_bus_lock(sigma_delta->spi->master); 291af300848SLars-Peter Clausen sigma_delta->bus_locked = true; 292df1d80aeSLars-Peter Clausen sigma_delta->keep_cs_asserted = true; 29316735d02SWolfram Sang reinit_completion(&sigma_delta->completion); 294af300848SLars-Peter Clausen 295af300848SLars-Peter Clausen ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_SINGLE); 296af300848SLars-Peter Clausen 297af300848SLars-Peter Clausen sigma_delta->irq_dis = false; 298af300848SLars-Peter Clausen enable_irq(sigma_delta->spi->irq); 299af300848SLars-Peter Clausen ret = wait_for_completion_interruptible_timeout( 300af300848SLars-Peter Clausen &sigma_delta->completion, HZ); 301af300848SLars-Peter Clausen 302af300848SLars-Peter Clausen if (ret == 0) 303af300848SLars-Peter Clausen ret = -EIO; 304af300848SLars-Peter Clausen if (ret < 0) 305af300848SLars-Peter Clausen goto out; 306af300848SLars-Peter Clausen 307f0aef2d0SLars-Peter Clausen if (sigma_delta->info->data_reg != 0) 308f0aef2d0SLars-Peter Clausen data_reg = sigma_delta->info->data_reg; 309f0aef2d0SLars-Peter Clausen else 310f0aef2d0SLars-Peter Clausen data_reg = AD_SD_REG_DATA; 311f0aef2d0SLars-Peter Clausen 312f0aef2d0SLars-Peter Clausen ret = ad_sd_read_reg(sigma_delta, data_reg, 313af300848SLars-Peter Clausen DIV_ROUND_UP(chan->scan_type.realbits + chan->scan_type.shift, 8), 314af300848SLars-Peter Clausen &raw_sample); 315af300848SLars-Peter Clausen 316af300848SLars-Peter Clausen out: 317af300848SLars-Peter Clausen if (!sigma_delta->irq_dis) { 318af300848SLars-Peter Clausen disable_irq_nosync(sigma_delta->spi->irq); 319af300848SLars-Peter Clausen sigma_delta->irq_dis = true; 320af300848SLars-Peter Clausen } 321af300848SLars-Peter Clausen 322df1d80aeSLars-Peter Clausen sigma_delta->keep_cs_asserted = false; 323af300848SLars-Peter Clausen ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); 324df1d80aeSLars-Peter Clausen sigma_delta->bus_locked = false; 325df1d80aeSLars-Peter Clausen spi_bus_unlock(sigma_delta->spi->master); 32620228a1dSNuno Sá iio_device_release_direct_mode(indio_dev); 327af300848SLars-Peter Clausen 328af300848SLars-Peter Clausen if (ret) 329af300848SLars-Peter Clausen return ret; 330af300848SLars-Peter Clausen 331af300848SLars-Peter Clausen sample = raw_sample >> chan->scan_type.shift; 332af300848SLars-Peter Clausen sample &= (1 << chan->scan_type.realbits) - 1; 333af300848SLars-Peter Clausen *val = sample; 334af300848SLars-Peter Clausen 335af300848SLars-Peter Clausen ret = ad_sigma_delta_postprocess_sample(sigma_delta, raw_sample); 336af300848SLars-Peter Clausen if (ret) 337af300848SLars-Peter Clausen return ret; 338af300848SLars-Peter Clausen 339af300848SLars-Peter Clausen return IIO_VAL_INT; 340af300848SLars-Peter Clausen } 341ef807729SJonathan Cameron EXPORT_SYMBOL_NS_GPL(ad_sigma_delta_single_conversion, IIO_AD_SIGMA_DELTA); 342af300848SLars-Peter Clausen 343af300848SLars-Peter Clausen static int ad_sd_buffer_postenable(struct iio_dev *indio_dev) 344af300848SLars-Peter Clausen { 345af300848SLars-Peter Clausen struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 3468bea9af8SLars-Peter Clausen unsigned int i, slot, samples_buf_size; 347af300848SLars-Peter Clausen unsigned int channel; 3488bea9af8SLars-Peter Clausen uint8_t *samples_buf; 349af300848SLars-Peter Clausen int ret; 350af300848SLars-Peter Clausen 3518bea9af8SLars-Peter Clausen if (sigma_delta->num_slots == 1) { 352af300848SLars-Peter Clausen channel = find_first_bit(indio_dev->active_scan_mask, 353af300848SLars-Peter Clausen indio_dev->masklength); 354af300848SLars-Peter Clausen ret = ad_sigma_delta_set_channel(sigma_delta, 355af300848SLars-Peter Clausen indio_dev->channels[channel].address); 356af300848SLars-Peter Clausen if (ret) 357387c1d77SAlexandru Ardelean return ret; 3588bea9af8SLars-Peter Clausen slot = 1; 3598bea9af8SLars-Peter Clausen } else { 3608bea9af8SLars-Peter Clausen /* 3618bea9af8SLars-Peter Clausen * At this point update_scan_mode already enabled the required channels. 3628bea9af8SLars-Peter Clausen * For sigma-delta sequencer drivers with multiple slots, an update_scan_mode 3638bea9af8SLars-Peter Clausen * implementation is mandatory. 3648bea9af8SLars-Peter Clausen */ 3658bea9af8SLars-Peter Clausen slot = 0; 3668bea9af8SLars-Peter Clausen for_each_set_bit(i, indio_dev->active_scan_mask, indio_dev->masklength) { 3678bea9af8SLars-Peter Clausen sigma_delta->slots[slot] = indio_dev->channels[i].address; 3688bea9af8SLars-Peter Clausen slot++; 3698bea9af8SLars-Peter Clausen } 3708bea9af8SLars-Peter Clausen } 3718bea9af8SLars-Peter Clausen 3728bea9af8SLars-Peter Clausen sigma_delta->active_slots = slot; 3738bea9af8SLars-Peter Clausen sigma_delta->current_slot = 0; 3748bea9af8SLars-Peter Clausen 3758bea9af8SLars-Peter Clausen if (sigma_delta->active_slots > 1) { 3768bea9af8SLars-Peter Clausen ret = ad_sigma_delta_append_status(sigma_delta, true); 3778bea9af8SLars-Peter Clausen if (ret) 3788bea9af8SLars-Peter Clausen return ret; 3798bea9af8SLars-Peter Clausen } 3808bea9af8SLars-Peter Clausen 3818bea9af8SLars-Peter Clausen samples_buf_size = ALIGN(slot * indio_dev->channels[0].scan_type.storagebits, 8); 3828bea9af8SLars-Peter Clausen samples_buf_size += sizeof(int64_t); 3838bea9af8SLars-Peter Clausen samples_buf = devm_krealloc(&sigma_delta->spi->dev, sigma_delta->samples_buf, 3848bea9af8SLars-Peter Clausen samples_buf_size, GFP_KERNEL); 3858bea9af8SLars-Peter Clausen if (!samples_buf) 3868bea9af8SLars-Peter Clausen return -ENOMEM; 3878bea9af8SLars-Peter Clausen 3888bea9af8SLars-Peter Clausen sigma_delta->samples_buf = samples_buf; 389af300848SLars-Peter Clausen 390af300848SLars-Peter Clausen spi_bus_lock(sigma_delta->spi->master); 391af300848SLars-Peter Clausen sigma_delta->bus_locked = true; 392df1d80aeSLars-Peter Clausen sigma_delta->keep_cs_asserted = true; 393df1d80aeSLars-Peter Clausen 394af300848SLars-Peter Clausen ret = ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_CONTINUOUS); 395af300848SLars-Peter Clausen if (ret) 396af300848SLars-Peter Clausen goto err_unlock; 397af300848SLars-Peter Clausen 398af300848SLars-Peter Clausen sigma_delta->irq_dis = false; 399af300848SLars-Peter Clausen enable_irq(sigma_delta->spi->irq); 400af300848SLars-Peter Clausen 401af300848SLars-Peter Clausen return 0; 402af300848SLars-Peter Clausen 403af300848SLars-Peter Clausen err_unlock: 404af300848SLars-Peter Clausen spi_bus_unlock(sigma_delta->spi->master); 405af300848SLars-Peter Clausen 406af300848SLars-Peter Clausen return ret; 407af300848SLars-Peter Clausen } 408af300848SLars-Peter Clausen 409af300848SLars-Peter Clausen static int ad_sd_buffer_postdisable(struct iio_dev *indio_dev) 410af300848SLars-Peter Clausen { 411af300848SLars-Peter Clausen struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 412af300848SLars-Peter Clausen 41316735d02SWolfram Sang reinit_completion(&sigma_delta->completion); 414af300848SLars-Peter Clausen wait_for_completion_timeout(&sigma_delta->completion, HZ); 415af300848SLars-Peter Clausen 416af300848SLars-Peter Clausen if (!sigma_delta->irq_dis) { 417af300848SLars-Peter Clausen disable_irq_nosync(sigma_delta->spi->irq); 418af300848SLars-Peter Clausen sigma_delta->irq_dis = true; 419af300848SLars-Peter Clausen } 420af300848SLars-Peter Clausen 421df1d80aeSLars-Peter Clausen sigma_delta->keep_cs_asserted = false; 422af300848SLars-Peter Clausen ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); 423af300848SLars-Peter Clausen 4248bea9af8SLars-Peter Clausen if (sigma_delta->status_appended) 4258bea9af8SLars-Peter Clausen ad_sigma_delta_append_status(sigma_delta, false); 4268bea9af8SLars-Peter Clausen 4278bea9af8SLars-Peter Clausen ad_sigma_delta_disable_all(sigma_delta); 428af300848SLars-Peter Clausen sigma_delta->bus_locked = false; 429af300848SLars-Peter Clausen return spi_bus_unlock(sigma_delta->spi->master); 430af300848SLars-Peter Clausen } 431af300848SLars-Peter Clausen 432af300848SLars-Peter Clausen static irqreturn_t ad_sd_trigger_handler(int irq, void *p) 433af300848SLars-Peter Clausen { 434af300848SLars-Peter Clausen struct iio_poll_func *pf = p; 435af300848SLars-Peter Clausen struct iio_dev *indio_dev = pf->indio_dev; 436af300848SLars-Peter Clausen struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 4370fb6ee8dSLars-Peter Clausen uint8_t *data = sigma_delta->rx_buf; 4388bea9af8SLars-Peter Clausen unsigned int transfer_size; 4398bea9af8SLars-Peter Clausen unsigned int sample_size; 4408bea9af8SLars-Peter Clausen unsigned int sample_pos; 4418bea9af8SLars-Peter Clausen unsigned int status_pos; 442af300848SLars-Peter Clausen unsigned int reg_size; 443f0aef2d0SLars-Peter Clausen unsigned int data_reg; 444af300848SLars-Peter Clausen 445af300848SLars-Peter Clausen reg_size = indio_dev->channels[0].scan_type.realbits + 446af300848SLars-Peter Clausen indio_dev->channels[0].scan_type.shift; 447af300848SLars-Peter Clausen reg_size = DIV_ROUND_UP(reg_size, 8); 448af300848SLars-Peter Clausen 449f0aef2d0SLars-Peter Clausen if (sigma_delta->info->data_reg != 0) 450f0aef2d0SLars-Peter Clausen data_reg = sigma_delta->info->data_reg; 451f0aef2d0SLars-Peter Clausen else 452f0aef2d0SLars-Peter Clausen data_reg = AD_SD_REG_DATA; 453f0aef2d0SLars-Peter Clausen 4548bea9af8SLars-Peter Clausen /* Status word will be appended to the sample during transfer */ 4558bea9af8SLars-Peter Clausen if (sigma_delta->status_appended) 4568bea9af8SLars-Peter Clausen transfer_size = reg_size + 1; 4578bea9af8SLars-Peter Clausen else 4588bea9af8SLars-Peter Clausen transfer_size = reg_size; 4598bea9af8SLars-Peter Clausen 460af300848SLars-Peter Clausen switch (reg_size) { 461af300848SLars-Peter Clausen case 4: 462af300848SLars-Peter Clausen case 2: 463af300848SLars-Peter Clausen case 1: 4648bea9af8SLars-Peter Clausen status_pos = reg_size; 4658bea9af8SLars-Peter Clausen ad_sd_read_reg_raw(sigma_delta, data_reg, transfer_size, &data[0]); 466af300848SLars-Peter Clausen break; 467af300848SLars-Peter Clausen case 3: 4688bea9af8SLars-Peter Clausen /* 4698bea9af8SLars-Peter Clausen * Data array after transfer will look like (if status is appended): 4708bea9af8SLars-Peter Clausen * data[] = { [0][sample][sample][sample][status] } 4718bea9af8SLars-Peter Clausen * Keeping the first byte 0 shifts the status postion by 1 byte to the right. 4728bea9af8SLars-Peter Clausen */ 4738bea9af8SLars-Peter Clausen status_pos = reg_size + 1; 4748bea9af8SLars-Peter Clausen 475af300848SLars-Peter Clausen /* We store 24 bit samples in a 32 bit word. Keep the upper 476af300848SLars-Peter Clausen * byte set to zero. */ 4778bea9af8SLars-Peter Clausen ad_sd_read_reg_raw(sigma_delta, data_reg, transfer_size, &data[1]); 478af300848SLars-Peter Clausen break; 479af300848SLars-Peter Clausen } 480af300848SLars-Peter Clausen 4818bea9af8SLars-Peter Clausen /* 4828bea9af8SLars-Peter Clausen * For devices sampling only one channel at 4838bea9af8SLars-Peter Clausen * once, there is no need for sample number tracking. 4848bea9af8SLars-Peter Clausen */ 4858bea9af8SLars-Peter Clausen if (sigma_delta->active_slots == 1) { 486a1be505fSLars-Peter Clausen iio_push_to_buffers_with_timestamp(indio_dev, data, pf->timestamp); 4878bea9af8SLars-Peter Clausen goto irq_handled; 4888bea9af8SLars-Peter Clausen } 489af300848SLars-Peter Clausen 4908bea9af8SLars-Peter Clausen if (sigma_delta->status_appended) { 4918bea9af8SLars-Peter Clausen u8 converted_channel; 4928bea9af8SLars-Peter Clausen 4938bea9af8SLars-Peter Clausen converted_channel = data[status_pos] & sigma_delta->info->status_ch_mask; 4948bea9af8SLars-Peter Clausen if (converted_channel != sigma_delta->slots[sigma_delta->current_slot]) { 4958bea9af8SLars-Peter Clausen /* 4968bea9af8SLars-Peter Clausen * Desync occurred during continuous sampling of multiple channels. 4978bea9af8SLars-Peter Clausen * Drop this incomplete sample and start from first channel again. 4988bea9af8SLars-Peter Clausen */ 4998bea9af8SLars-Peter Clausen 5008bea9af8SLars-Peter Clausen sigma_delta->current_slot = 0; 5018bea9af8SLars-Peter Clausen goto irq_handled; 5028bea9af8SLars-Peter Clausen } 5038bea9af8SLars-Peter Clausen } 5048bea9af8SLars-Peter Clausen 5058bea9af8SLars-Peter Clausen sample_size = indio_dev->channels[0].scan_type.storagebits / 8; 5068bea9af8SLars-Peter Clausen sample_pos = sample_size * sigma_delta->current_slot; 5078bea9af8SLars-Peter Clausen memcpy(&sigma_delta->samples_buf[sample_pos], data, sample_size); 5088bea9af8SLars-Peter Clausen sigma_delta->current_slot++; 5098bea9af8SLars-Peter Clausen 5108bea9af8SLars-Peter Clausen if (sigma_delta->current_slot == sigma_delta->active_slots) { 5118bea9af8SLars-Peter Clausen sigma_delta->current_slot = 0; 5128bea9af8SLars-Peter Clausen iio_push_to_buffers_with_timestamp(indio_dev, sigma_delta->samples_buf, 5138bea9af8SLars-Peter Clausen pf->timestamp); 5148bea9af8SLars-Peter Clausen } 5158bea9af8SLars-Peter Clausen 5168bea9af8SLars-Peter Clausen irq_handled: 517af300848SLars-Peter Clausen iio_trigger_notify_done(indio_dev->trig); 518af300848SLars-Peter Clausen sigma_delta->irq_dis = false; 519af300848SLars-Peter Clausen enable_irq(sigma_delta->spi->irq); 520af300848SLars-Peter Clausen 521af300848SLars-Peter Clausen return IRQ_HANDLED; 522af300848SLars-Peter Clausen } 523af300848SLars-Peter Clausen 5248bea9af8SLars-Peter Clausen static bool ad_sd_validate_scan_mask(struct iio_dev *indio_dev, const unsigned long *mask) 5258bea9af8SLars-Peter Clausen { 5268bea9af8SLars-Peter Clausen struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 5278bea9af8SLars-Peter Clausen 5288bea9af8SLars-Peter Clausen return bitmap_weight(mask, indio_dev->masklength) <= sigma_delta->num_slots; 5298bea9af8SLars-Peter Clausen } 5308bea9af8SLars-Peter Clausen 531af300848SLars-Peter Clausen static const struct iio_buffer_setup_ops ad_sd_buffer_setup_ops = { 532af300848SLars-Peter Clausen .postenable = &ad_sd_buffer_postenable, 533af300848SLars-Peter Clausen .postdisable = &ad_sd_buffer_postdisable, 5348bea9af8SLars-Peter Clausen .validate_scan_mask = &ad_sd_validate_scan_mask, 535af300848SLars-Peter Clausen }; 536af300848SLars-Peter Clausen 537af300848SLars-Peter Clausen static irqreturn_t ad_sd_data_rdy_trig_poll(int irq, void *private) 538af300848SLars-Peter Clausen { 539af300848SLars-Peter Clausen struct ad_sigma_delta *sigma_delta = private; 540af300848SLars-Peter Clausen 541af300848SLars-Peter Clausen complete(&sigma_delta->completion); 542af300848SLars-Peter Clausen disable_irq_nosync(irq); 543af300848SLars-Peter Clausen sigma_delta->irq_dis = true; 544398fd22bSPeter Meerwald iio_trigger_poll(sigma_delta->trig); 545af300848SLars-Peter Clausen 546af300848SLars-Peter Clausen return IRQ_HANDLED; 547af300848SLars-Peter Clausen } 548af300848SLars-Peter Clausen 549af300848SLars-Peter Clausen /** 550af300848SLars-Peter Clausen * ad_sd_validate_trigger() - validate_trigger callback for ad_sigma_delta devices 551af300848SLars-Peter Clausen * @indio_dev: The IIO device 552af300848SLars-Peter Clausen * @trig: The new trigger 553af300848SLars-Peter Clausen * 554af300848SLars-Peter Clausen * Returns: 0 if the 'trig' matches the trigger registered by the ad_sigma_delta 555af300848SLars-Peter Clausen * device, -EINVAL otherwise. 556af300848SLars-Peter Clausen */ 557af300848SLars-Peter Clausen int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig) 558af300848SLars-Peter Clausen { 559af300848SLars-Peter Clausen struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 560af300848SLars-Peter Clausen 561af300848SLars-Peter Clausen if (sigma_delta->trig != trig) 562af300848SLars-Peter Clausen return -EINVAL; 563af300848SLars-Peter Clausen 564af300848SLars-Peter Clausen return 0; 565af300848SLars-Peter Clausen } 566ef807729SJonathan Cameron EXPORT_SYMBOL_NS_GPL(ad_sd_validate_trigger, IIO_AD_SIGMA_DELTA); 567af300848SLars-Peter Clausen 568718fb2bcSAlexandru Ardelean static int devm_ad_sd_probe_trigger(struct device *dev, struct iio_dev *indio_dev) 569718fb2bcSAlexandru Ardelean { 570718fb2bcSAlexandru Ardelean struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 571718fb2bcSAlexandru Ardelean int ret; 572718fb2bcSAlexandru Ardelean 573718fb2bcSAlexandru Ardelean if (dev != &sigma_delta->spi->dev) { 574718fb2bcSAlexandru Ardelean dev_err(dev, "Trigger parent should be '%s', got '%s'\n", 575718fb2bcSAlexandru Ardelean dev_name(dev), dev_name(&sigma_delta->spi->dev)); 576718fb2bcSAlexandru Ardelean return -EFAULT; 577718fb2bcSAlexandru Ardelean } 578718fb2bcSAlexandru Ardelean 579718fb2bcSAlexandru Ardelean sigma_delta->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name, 580718fb2bcSAlexandru Ardelean iio_device_id(indio_dev)); 581718fb2bcSAlexandru Ardelean if (sigma_delta->trig == NULL) 582718fb2bcSAlexandru Ardelean return -ENOMEM; 583718fb2bcSAlexandru Ardelean 584718fb2bcSAlexandru Ardelean init_completion(&sigma_delta->completion); 585718fb2bcSAlexandru Ardelean 586718fb2bcSAlexandru Ardelean sigma_delta->irq_dis = true; 587*626d3120SMasahiro Honda 588*626d3120SMasahiro Honda /* the IRQ core clears IRQ_DISABLE_UNLAZY flag when freeing an IRQ */ 589*626d3120SMasahiro Honda irq_set_status_flags(sigma_delta->spi->irq, IRQ_DISABLE_UNLAZY); 590*626d3120SMasahiro Honda 591718fb2bcSAlexandru Ardelean ret = devm_request_irq(dev, sigma_delta->spi->irq, 592718fb2bcSAlexandru Ardelean ad_sd_data_rdy_trig_poll, 593718fb2bcSAlexandru Ardelean sigma_delta->info->irq_flags | IRQF_NO_AUTOEN, 594718fb2bcSAlexandru Ardelean indio_dev->name, 595718fb2bcSAlexandru Ardelean sigma_delta); 596718fb2bcSAlexandru Ardelean if (ret) 597718fb2bcSAlexandru Ardelean return ret; 598718fb2bcSAlexandru Ardelean 599718fb2bcSAlexandru Ardelean iio_trigger_set_drvdata(sigma_delta->trig, sigma_delta); 600718fb2bcSAlexandru Ardelean 601718fb2bcSAlexandru Ardelean ret = devm_iio_trigger_register(dev, sigma_delta->trig); 602718fb2bcSAlexandru Ardelean if (ret) 603718fb2bcSAlexandru Ardelean return ret; 604718fb2bcSAlexandru Ardelean 605718fb2bcSAlexandru Ardelean /* select default trigger */ 606718fb2bcSAlexandru Ardelean indio_dev->trig = iio_trigger_get(sigma_delta->trig); 607718fb2bcSAlexandru Ardelean 608718fb2bcSAlexandru Ardelean return 0; 609718fb2bcSAlexandru Ardelean } 610718fb2bcSAlexandru Ardelean 611af300848SLars-Peter Clausen /** 612718fb2bcSAlexandru Ardelean * devm_ad_sd_setup_buffer_and_trigger() - Device-managed buffer & trigger setup 613718fb2bcSAlexandru Ardelean * @dev: Device object to which to bind the life-time of the resources attached 614718fb2bcSAlexandru Ardelean * @indio_dev: The IIO device 615718fb2bcSAlexandru Ardelean */ 616718fb2bcSAlexandru Ardelean int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev) 617718fb2bcSAlexandru Ardelean { 6188bea9af8SLars-Peter Clausen struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 619718fb2bcSAlexandru Ardelean int ret; 620718fb2bcSAlexandru Ardelean 6218bea9af8SLars-Peter Clausen sigma_delta->slots = devm_kcalloc(dev, sigma_delta->num_slots, 6228bea9af8SLars-Peter Clausen sizeof(*sigma_delta->slots), GFP_KERNEL); 6238bea9af8SLars-Peter Clausen if (!sigma_delta->slots) 6248bea9af8SLars-Peter Clausen return -ENOMEM; 6258bea9af8SLars-Peter Clausen 626718fb2bcSAlexandru Ardelean ret = devm_iio_triggered_buffer_setup(dev, indio_dev, 627718fb2bcSAlexandru Ardelean &iio_pollfunc_store_time, 628718fb2bcSAlexandru Ardelean &ad_sd_trigger_handler, 629718fb2bcSAlexandru Ardelean &ad_sd_buffer_setup_ops); 630718fb2bcSAlexandru Ardelean if (ret) 631718fb2bcSAlexandru Ardelean return ret; 632718fb2bcSAlexandru Ardelean 633718fb2bcSAlexandru Ardelean return devm_ad_sd_probe_trigger(dev, indio_dev); 634718fb2bcSAlexandru Ardelean } 635ef807729SJonathan Cameron EXPORT_SYMBOL_NS_GPL(devm_ad_sd_setup_buffer_and_trigger, IIO_AD_SIGMA_DELTA); 636718fb2bcSAlexandru Ardelean 637718fb2bcSAlexandru Ardelean /** 638af300848SLars-Peter Clausen * ad_sd_init() - Initializes a ad_sigma_delta struct 639af300848SLars-Peter Clausen * @sigma_delta: The ad_sigma_delta device 640af300848SLars-Peter Clausen * @indio_dev: The IIO device which the Sigma Delta device is used for 641af300848SLars-Peter Clausen * @spi: The SPI device for the ad_sigma_delta device 642af300848SLars-Peter Clausen * @info: Device specific callbacks and options 643af300848SLars-Peter Clausen * 644af300848SLars-Peter Clausen * This function needs to be called before any other operations are performed on 645af300848SLars-Peter Clausen * the ad_sigma_delta struct. 646af300848SLars-Peter Clausen */ 647af300848SLars-Peter Clausen int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev, 648af300848SLars-Peter Clausen struct spi_device *spi, const struct ad_sigma_delta_info *info) 649af300848SLars-Peter Clausen { 650af300848SLars-Peter Clausen sigma_delta->spi = spi; 651af300848SLars-Peter Clausen sigma_delta->info = info; 6528bea9af8SLars-Peter Clausen 6538bea9af8SLars-Peter Clausen /* If the field is unset in ad_sigma_delta_info, asume there can only be 1 slot. */ 6548bea9af8SLars-Peter Clausen if (!info->num_slots) 6558bea9af8SLars-Peter Clausen sigma_delta->num_slots = 1; 6568bea9af8SLars-Peter Clausen else 6578bea9af8SLars-Peter Clausen sigma_delta->num_slots = info->num_slots; 6588bea9af8SLars-Peter Clausen 6598bea9af8SLars-Peter Clausen if (sigma_delta->num_slots > 1) { 6608bea9af8SLars-Peter Clausen if (!indio_dev->info->update_scan_mode) { 6618bea9af8SLars-Peter Clausen dev_err(&spi->dev, "iio_dev lacks update_scan_mode().\n"); 6628bea9af8SLars-Peter Clausen return -EINVAL; 6638bea9af8SLars-Peter Clausen } 6648bea9af8SLars-Peter Clausen 6658bea9af8SLars-Peter Clausen if (!info->disable_all) { 6668bea9af8SLars-Peter Clausen dev_err(&spi->dev, "ad_sigma_delta_info lacks disable_all().\n"); 6678bea9af8SLars-Peter Clausen return -EINVAL; 6688bea9af8SLars-Peter Clausen } 6698bea9af8SLars-Peter Clausen } 6708bea9af8SLars-Peter Clausen 671af300848SLars-Peter Clausen iio_device_set_drvdata(indio_dev, sigma_delta); 672af300848SLars-Peter Clausen 673af300848SLars-Peter Clausen return 0; 674af300848SLars-Peter Clausen } 675ef807729SJonathan Cameron EXPORT_SYMBOL_NS_GPL(ad_sd_init, IIO_AD_SIGMA_DELTA); 676af300848SLars-Peter Clausen 677af300848SLars-Peter Clausen MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 678af300848SLars-Peter Clausen MODULE_DESCRIPTION("Analog Devices Sigma-Delta ADCs"); 679af300848SLars-Peter Clausen MODULE_LICENSE("GPL v2"); 680