cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

ad5770r.c (17587B)


      1// SPDX-License-Identifier: GPL-2.0+
      2/*
      3 * AD5770R Digital to analog converters driver
      4 *
      5 * Copyright 2018 Analog Devices Inc.
      6 */
      7
      8#include <linux/bits.h>
      9#include <linux/delay.h>
     10#include <linux/device.h>
     11#include <linux/gpio/consumer.h>
     12#include <linux/iio/iio.h>
     13#include <linux/iio/sysfs.h>
     14#include <linux/kernel.h>
     15#include <linux/module.h>
     16#include <linux/property.h>
     17#include <linux/regmap.h>
     18#include <linux/regulator/consumer.h>
     19#include <linux/spi/spi.h>
     20
     21#define ADI_SPI_IF_CONFIG_A		0x00
     22#define ADI_SPI_IF_CONFIG_B		0x01
     23#define ADI_SPI_IF_DEVICE_CONFIG	0x02
     24#define ADI_SPI_IF_CHIP_TYPE		0x03
     25#define ADI_SPI_IF_PRODUCT_ID_L		0x04
     26#define ADI_SPI_IF_PRODUCT_ID_H		0x05
     27#define ADI_SPI_IF_CHIP_GRADE		0x06
     28#define ADI_SPI_IF_SCRACTH_PAD		0x0A
     29#define ADI_SPI_IF_SPI_REVISION		0x0B
     30#define ADI_SPI_IF_SPI_VENDOR_L		0x0C
     31#define ADI_SPI_IF_SPI_VENDOR_H		0x0D
     32#define ADI_SPI_IF_SPI_STREAM_MODE	0x0E
     33#define ADI_SPI_IF_CONFIG_C		0x10
     34#define ADI_SPI_IF_STATUS_A		0x11
     35
     36/* ADI_SPI_IF_CONFIG_A */
     37#define ADI_SPI_IF_SW_RESET_MSK		(BIT(0) | BIT(7))
     38#define ADI_SPI_IF_SW_RESET_SEL(x)	((x) & ADI_SPI_IF_SW_RESET_MSK)
     39#define ADI_SPI_IF_ADDR_ASC_MSK		(BIT(2) | BIT(5))
     40#define ADI_SPI_IF_ADDR_ASC_SEL(x)	(((x) << 2) & ADI_SPI_IF_ADDR_ASC_MSK)
     41
     42/* ADI_SPI_IF_CONFIG_B */
     43#define ADI_SPI_IF_SINGLE_INS_MSK	BIT(7)
     44#define ADI_SPI_IF_SINGLE_INS_SEL(x)	FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
     45#define ADI_SPI_IF_SHORT_INS_MSK	BIT(7)
     46#define ADI_SPI_IF_SHORT_INS_SEL(x)	FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)
     47
     48/* ADI_SPI_IF_CONFIG_C */
     49#define ADI_SPI_IF_STRICT_REG_MSK	BIT(5)
     50#define ADI_SPI_IF_STRICT_REG_GET(x)	FIELD_GET(ADI_SPI_IF_STRICT_REG_MSK, x)
     51
     52/* AD5770R configuration registers */
     53#define AD5770R_CHANNEL_CONFIG		0x14
     54#define AD5770R_OUTPUT_RANGE(ch)	(0x15 + (ch))
     55#define AD5770R_FILTER_RESISTOR(ch)	(0x1D + (ch))
     56#define AD5770R_REFERENCE		0x1B
     57#define AD5770R_DAC_LSB(ch)		(0x26 + 2 * (ch))
     58#define AD5770R_DAC_MSB(ch)		(0x27 + 2 * (ch))
     59#define AD5770R_CH_SELECT		0x34
     60#define AD5770R_CH_ENABLE		0x44
     61
     62/* AD5770R_CHANNEL_CONFIG */
     63#define AD5770R_CFG_CH0_SINK_EN(x)		(((x) & 0x1) << 7)
     64#define AD5770R_CFG_SHUTDOWN_B(x, ch)		(((x) & 0x1) << (ch))
     65
     66/* AD5770R_OUTPUT_RANGE */
     67#define AD5770R_RANGE_OUTPUT_SCALING(x)		(((x) & GENMASK(5, 0)) << 2)
     68#define AD5770R_RANGE_MODE(x)			((x) & GENMASK(1, 0))
     69
     70/* AD5770R_REFERENCE */
     71#define AD5770R_REF_RESISTOR_SEL(x)		(((x) & 0x1) << 2)
     72#define AD5770R_REF_SEL(x)			((x) & GENMASK(1, 0))
     73
     74/* AD5770R_CH_ENABLE */
     75#define AD5770R_CH_SET(x, ch)		(((x) & 0x1) << (ch))
     76
     77#define AD5770R_MAX_CHANNELS	6
     78#define AD5770R_MAX_CH_MODES	14
     79#define AD5770R_LOW_VREF_mV	1250
     80#define AD5770R_HIGH_VREF_mV	2500
     81
     82enum ad5770r_ch0_modes {
     83	AD5770R_CH0_0_300 = 0,
     84	AD5770R_CH0_NEG_60_0,
     85	AD5770R_CH0_NEG_60_300
     86};
     87
     88enum ad5770r_ch1_modes {
     89	AD5770R_CH1_0_140_LOW_HEAD = 1,
     90	AD5770R_CH1_0_140_LOW_NOISE,
     91	AD5770R_CH1_0_250
     92};
     93
     94enum ad5770r_ch2_5_modes {
     95	AD5770R_CH_LOW_RANGE = 0,
     96	AD5770R_CH_HIGH_RANGE
     97};
     98
     99enum ad5770r_ref_v {
    100	AD5770R_EXT_2_5_V = 0,
    101	AD5770R_INT_1_25_V_OUT_ON,
    102	AD5770R_EXT_1_25_V,
    103	AD5770R_INT_1_25_V_OUT_OFF
    104};
    105
    106enum ad5770r_output_filter_resistor {
    107	AD5770R_FILTER_60_OHM = 0x0,
    108	AD5770R_FILTER_5_6_KOHM = 0x5,
    109	AD5770R_FILTER_11_2_KOHM,
    110	AD5770R_FILTER_22_2_KOHM,
    111	AD5770R_FILTER_44_4_KOHM,
    112	AD5770R_FILTER_104_KOHM,
    113};
    114
    115struct ad5770r_out_range {
    116	u8	out_scale;
    117	u8	out_range_mode;
    118};
    119
    120/**
    121 * struct ad5770r_state - driver instance specific data
    122 * @spi:		spi_device
    123 * @regmap:		regmap
    124 * @vref_reg:		fixed regulator for reference configuration
    125 * @gpio_reset:		gpio descriptor
    126 * @output_mode:	array contains channels output ranges
    127 * @vref:		reference value
    128 * @ch_pwr_down:	powerdown flags
    129 * @internal_ref:	internal reference flag
    130 * @external_res:	external 2.5k resistor flag
    131 * @transf_buf:		cache aligned buffer for spi read/write
    132 */
    133struct ad5770r_state {
    134	struct spi_device		*spi;
    135	struct regmap			*regmap;
    136	struct regulator		*vref_reg;
    137	struct gpio_desc		*gpio_reset;
    138	struct ad5770r_out_range	output_mode[AD5770R_MAX_CHANNELS];
    139	int				vref;
    140	bool				ch_pwr_down[AD5770R_MAX_CHANNELS];
    141	bool				internal_ref;
    142	bool				external_res;
    143	u8				transf_buf[2] ____cacheline_aligned;
    144};
    145
    146static const struct regmap_config ad5770r_spi_regmap_config = {
    147	.reg_bits = 8,
    148	.val_bits = 8,
    149	.read_flag_mask = BIT(7),
    150};
    151
    152struct ad5770r_output_modes {
    153	unsigned int ch;
    154	u8 mode;
    155	int min;
    156	int max;
    157};
    158
    159static struct ad5770r_output_modes ad5770r_rng_tbl[] = {
    160	{ 0, AD5770R_CH0_0_300, 0, 300 },
    161	{ 0, AD5770R_CH0_NEG_60_0, -60, 0 },
    162	{ 0, AD5770R_CH0_NEG_60_300, -60, 300 },
    163	{ 1, AD5770R_CH1_0_140_LOW_HEAD, 0, 140 },
    164	{ 1, AD5770R_CH1_0_140_LOW_NOISE, 0, 140 },
    165	{ 1, AD5770R_CH1_0_250, 0, 250 },
    166	{ 2, AD5770R_CH_LOW_RANGE, 0, 55 },
    167	{ 2, AD5770R_CH_HIGH_RANGE, 0, 150 },
    168	{ 3, AD5770R_CH_LOW_RANGE, 0, 45 },
    169	{ 3, AD5770R_CH_HIGH_RANGE, 0, 100 },
    170	{ 4, AD5770R_CH_LOW_RANGE, 0, 45 },
    171	{ 4, AD5770R_CH_HIGH_RANGE, 0, 100 },
    172	{ 5, AD5770R_CH_LOW_RANGE, 0, 45 },
    173	{ 5, AD5770R_CH_HIGH_RANGE, 0, 100 },
    174};
    175
    176static const unsigned int ad5770r_filter_freqs[] = {
    177	153, 357, 715, 1400, 2800, 262000,
    178};
    179
    180static const unsigned int ad5770r_filter_reg_vals[] = {
    181	AD5770R_FILTER_104_KOHM,
    182	AD5770R_FILTER_44_4_KOHM,
    183	AD5770R_FILTER_22_2_KOHM,
    184	AD5770R_FILTER_11_2_KOHM,
    185	AD5770R_FILTER_5_6_KOHM,
    186	AD5770R_FILTER_60_OHM
    187};
    188
    189static int ad5770r_set_output_mode(struct ad5770r_state *st,
    190				   const struct ad5770r_out_range *out_mode,
    191				   int channel)
    192{
    193	unsigned int regval;
    194
    195	regval = AD5770R_RANGE_OUTPUT_SCALING(out_mode->out_scale) |
    196		 AD5770R_RANGE_MODE(out_mode->out_range_mode);
    197
    198	return regmap_write(st->regmap,
    199			    AD5770R_OUTPUT_RANGE(channel), regval);
    200}
    201
    202static int ad5770r_set_reference(struct ad5770r_state *st)
    203{
    204	unsigned int regval;
    205
    206	regval = AD5770R_REF_RESISTOR_SEL(st->external_res);
    207
    208	if (st->internal_ref) {
    209		regval |= AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
    210	} else {
    211		switch (st->vref) {
    212		case AD5770R_LOW_VREF_mV:
    213			regval |= AD5770R_REF_SEL(AD5770R_EXT_1_25_V);
    214			break;
    215		case AD5770R_HIGH_VREF_mV:
    216			regval |= AD5770R_REF_SEL(AD5770R_EXT_2_5_V);
    217			break;
    218		default:
    219			regval = AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);
    220			break;
    221		}
    222	}
    223
    224	return regmap_write(st->regmap, AD5770R_REFERENCE, regval);
    225}
    226
    227static int ad5770r_soft_reset(struct ad5770r_state *st)
    228{
    229	return regmap_write(st->regmap, ADI_SPI_IF_CONFIG_A,
    230			    ADI_SPI_IF_SW_RESET_SEL(1));
    231}
    232
    233static int ad5770r_reset(struct ad5770r_state *st)
    234{
    235	/* Perform software reset if no GPIO provided */
    236	if (!st->gpio_reset)
    237		return ad5770r_soft_reset(st);
    238
    239	gpiod_set_value_cansleep(st->gpio_reset, 0);
    240	usleep_range(10, 20);
    241	gpiod_set_value_cansleep(st->gpio_reset, 1);
    242
    243	/* data must not be written during reset timeframe */
    244	usleep_range(100, 200);
    245
    246	return 0;
    247}
    248
    249static int ad5770r_get_range(struct ad5770r_state *st,
    250			     int ch, int *min, int *max)
    251{
    252	int i;
    253	u8 tbl_ch, tbl_mode, out_range;
    254
    255	out_range = st->output_mode[ch].out_range_mode;
    256
    257	for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
    258		tbl_ch = ad5770r_rng_tbl[i].ch;
    259		tbl_mode = ad5770r_rng_tbl[i].mode;
    260		if (tbl_ch == ch && tbl_mode == out_range) {
    261			*min = ad5770r_rng_tbl[i].min;
    262			*max = ad5770r_rng_tbl[i].max;
    263			return 0;
    264		}
    265	}
    266
    267	return -EINVAL;
    268}
    269
    270static int ad5770r_get_filter_freq(struct iio_dev *indio_dev,
    271				   const struct iio_chan_spec *chan, int *freq)
    272{
    273	struct ad5770r_state *st = iio_priv(indio_dev);
    274	int ret;
    275	unsigned int regval, i;
    276
    277	ret = regmap_read(st->regmap,
    278			  AD5770R_FILTER_RESISTOR(chan->channel), &regval);
    279	if (ret < 0)
    280		return ret;
    281
    282	for (i = 0; i < ARRAY_SIZE(ad5770r_filter_reg_vals); i++)
    283		if (regval == ad5770r_filter_reg_vals[i])
    284			break;
    285	if (i == ARRAY_SIZE(ad5770r_filter_reg_vals))
    286		return -EINVAL;
    287
    288	*freq = ad5770r_filter_freqs[i];
    289
    290	return IIO_VAL_INT;
    291}
    292
    293static int ad5770r_set_filter_freq(struct iio_dev *indio_dev,
    294				   const struct iio_chan_spec *chan,
    295				   unsigned int freq)
    296{
    297	struct ad5770r_state *st = iio_priv(indio_dev);
    298	unsigned int regval, i;
    299
    300	for (i = 0; i < ARRAY_SIZE(ad5770r_filter_freqs); i++)
    301		if (ad5770r_filter_freqs[i] >= freq)
    302			break;
    303	if (i == ARRAY_SIZE(ad5770r_filter_freqs))
    304		return -EINVAL;
    305
    306	regval = ad5770r_filter_reg_vals[i];
    307
    308	return regmap_write(st->regmap, AD5770R_FILTER_RESISTOR(chan->channel),
    309			    regval);
    310}
    311
    312static int ad5770r_read_raw(struct iio_dev *indio_dev,
    313			    struct iio_chan_spec const *chan,
    314			    int *val, int *val2, long info)
    315{
    316	struct ad5770r_state *st = iio_priv(indio_dev);
    317	int max, min, ret;
    318	u16 buf16;
    319
    320	switch (info) {
    321	case IIO_CHAN_INFO_RAW:
    322		ret = regmap_bulk_read(st->regmap,
    323				       chan->address,
    324				       st->transf_buf, 2);
    325		if (ret)
    326			return 0;
    327
    328		buf16 = st->transf_buf[0] + (st->transf_buf[1] << 8);
    329		*val = buf16 >> 2;
    330		return IIO_VAL_INT;
    331	case IIO_CHAN_INFO_SCALE:
    332		ret = ad5770r_get_range(st, chan->channel, &min, &max);
    333		if (ret < 0)
    334			return ret;
    335		*val = max - min;
    336		/* There is no sign bit. (negative current is mapped from 0)
    337		 * (sourced/sinked) current = raw * scale + offset
    338		 * where offset in case of CH0 can be negative.
    339		 */
    340		*val2 = 14;
    341		return IIO_VAL_FRACTIONAL_LOG2;
    342	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
    343		return ad5770r_get_filter_freq(indio_dev, chan, val);
    344	case IIO_CHAN_INFO_OFFSET:
    345		ret = ad5770r_get_range(st, chan->channel, &min, &max);
    346		if (ret < 0)
    347			return ret;
    348		*val = min;
    349		return IIO_VAL_INT;
    350	default:
    351		return -EINVAL;
    352	}
    353}
    354
    355static int ad5770r_write_raw(struct iio_dev *indio_dev,
    356			     struct iio_chan_spec const *chan,
    357			     int val, int val2, long info)
    358{
    359	struct ad5770r_state *st = iio_priv(indio_dev);
    360
    361	switch (info) {
    362	case IIO_CHAN_INFO_RAW:
    363		st->transf_buf[0] = ((u16)val >> 6);
    364		st->transf_buf[1] = (val & GENMASK(5, 0)) << 2;
    365		return regmap_bulk_write(st->regmap, chan->address,
    366					 st->transf_buf, 2);
    367	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
    368		return ad5770r_set_filter_freq(indio_dev, chan, val);
    369	default:
    370		return -EINVAL;
    371	}
    372}
    373
    374static int ad5770r_read_freq_avail(struct iio_dev *indio_dev,
    375				   struct iio_chan_spec const *chan,
    376				   const int **vals, int *type, int *length,
    377				   long mask)
    378{
    379	switch (mask) {
    380	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
    381		*type = IIO_VAL_INT;
    382		*vals = ad5770r_filter_freqs;
    383		*length = ARRAY_SIZE(ad5770r_filter_freqs);
    384		return IIO_AVAIL_LIST;
    385	}
    386
    387	return -EINVAL;
    388}
    389
    390static int ad5770r_reg_access(struct iio_dev *indio_dev,
    391			      unsigned int reg,
    392			      unsigned int writeval,
    393			      unsigned int *readval)
    394{
    395	struct ad5770r_state *st = iio_priv(indio_dev);
    396
    397	if (readval)
    398		return regmap_read(st->regmap, reg, readval);
    399	else
    400		return regmap_write(st->regmap, reg, writeval);
    401}
    402
    403static const struct iio_info ad5770r_info = {
    404	.read_raw = ad5770r_read_raw,
    405	.write_raw = ad5770r_write_raw,
    406	.read_avail = ad5770r_read_freq_avail,
    407	.debugfs_reg_access = &ad5770r_reg_access,
    408};
    409
    410static int ad5770r_store_output_range(struct ad5770r_state *st,
    411				      int min, int max, int index)
    412{
    413	int i;
    414
    415	for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {
    416		if (ad5770r_rng_tbl[i].ch != index)
    417			continue;
    418		if (ad5770r_rng_tbl[i].min != min ||
    419		    ad5770r_rng_tbl[i].max != max)
    420			continue;
    421		st->output_mode[index].out_range_mode = ad5770r_rng_tbl[i].mode;
    422
    423		return 0;
    424	}
    425
    426	return -EINVAL;
    427}
    428
    429static ssize_t ad5770r_read_dac_powerdown(struct iio_dev *indio_dev,
    430					  uintptr_t private,
    431					  const struct iio_chan_spec *chan,
    432					  char *buf)
    433{
    434	struct ad5770r_state *st = iio_priv(indio_dev);
    435
    436	return sysfs_emit(buf, "%d\n", st->ch_pwr_down[chan->channel]);
    437}
    438
    439static ssize_t ad5770r_write_dac_powerdown(struct iio_dev *indio_dev,
    440					   uintptr_t private,
    441					   const struct iio_chan_spec *chan,
    442					   const char *buf, size_t len)
    443{
    444	struct ad5770r_state *st = iio_priv(indio_dev);
    445	unsigned int regval;
    446	unsigned int mask;
    447	bool readin;
    448	int ret;
    449
    450	ret = kstrtobool(buf, &readin);
    451	if (ret)
    452		return ret;
    453
    454	readin = !readin;
    455
    456	regval = AD5770R_CFG_SHUTDOWN_B(readin, chan->channel);
    457	if (chan->channel == 0 &&
    458	    st->output_mode[0].out_range_mode > AD5770R_CH0_0_300) {
    459		regval |= AD5770R_CFG_CH0_SINK_EN(readin);
    460		mask = BIT(chan->channel) + BIT(7);
    461	} else {
    462		mask = BIT(chan->channel);
    463	}
    464	ret = regmap_update_bits(st->regmap, AD5770R_CHANNEL_CONFIG, mask,
    465				 regval);
    466	if (ret)
    467		return ret;
    468
    469	regval = AD5770R_CH_SET(readin, chan->channel);
    470	ret = regmap_update_bits(st->regmap, AD5770R_CH_ENABLE,
    471				 BIT(chan->channel), regval);
    472	if (ret)
    473		return ret;
    474
    475	st->ch_pwr_down[chan->channel] = !readin;
    476
    477	return len;
    478}
    479
    480static const struct iio_chan_spec_ext_info ad5770r_ext_info[] = {
    481	{
    482		.name = "powerdown",
    483		.read = ad5770r_read_dac_powerdown,
    484		.write = ad5770r_write_dac_powerdown,
    485		.shared = IIO_SEPARATE,
    486	},
    487	{ }
    488};
    489
    490#define AD5770R_IDAC_CHANNEL(index, reg) {				\
    491	.type = IIO_CURRENT,						\
    492	.address = reg,							\
    493	.indexed = 1,							\
    494	.channel = index,						\
    495	.output = 1,							\
    496	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
    497		BIT(IIO_CHAN_INFO_SCALE) |				\
    498		BIT(IIO_CHAN_INFO_OFFSET) |				\
    499		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
    500	.info_mask_shared_by_type_available =				\
    501		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
    502	.ext_info = ad5770r_ext_info,					\
    503}
    504
    505static const struct iio_chan_spec ad5770r_channels[] = {
    506	AD5770R_IDAC_CHANNEL(0, AD5770R_DAC_MSB(0)),
    507	AD5770R_IDAC_CHANNEL(1, AD5770R_DAC_MSB(1)),
    508	AD5770R_IDAC_CHANNEL(2, AD5770R_DAC_MSB(2)),
    509	AD5770R_IDAC_CHANNEL(3, AD5770R_DAC_MSB(3)),
    510	AD5770R_IDAC_CHANNEL(4, AD5770R_DAC_MSB(4)),
    511	AD5770R_IDAC_CHANNEL(5, AD5770R_DAC_MSB(5)),
    512};
    513
    514static int ad5770r_channel_config(struct ad5770r_state *st)
    515{
    516	int ret, tmp[2], min, max;
    517	unsigned int num;
    518	struct fwnode_handle *child;
    519
    520	num = device_get_child_node_count(&st->spi->dev);
    521	if (num != AD5770R_MAX_CHANNELS)
    522		return -EINVAL;
    523
    524	device_for_each_child_node(&st->spi->dev, child) {
    525		ret = fwnode_property_read_u32(child, "reg", &num);
    526		if (ret)
    527			goto err_child_out;
    528		if (num >= AD5770R_MAX_CHANNELS) {
    529			ret = -EINVAL;
    530			goto err_child_out;
    531		}
    532
    533		ret = fwnode_property_read_u32_array(child,
    534						     "adi,range-microamp",
    535						     tmp, 2);
    536		if (ret)
    537			goto err_child_out;
    538
    539		min = tmp[0] / 1000;
    540		max = tmp[1] / 1000;
    541		ret = ad5770r_store_output_range(st, min, max, num);
    542		if (ret)
    543			goto err_child_out;
    544	}
    545
    546	return 0;
    547
    548err_child_out:
    549	fwnode_handle_put(child);
    550	return ret;
    551}
    552
    553static int ad5770r_init(struct ad5770r_state *st)
    554{
    555	int ret, i;
    556
    557	st->gpio_reset = devm_gpiod_get_optional(&st->spi->dev, "reset",
    558						 GPIOD_OUT_HIGH);
    559	if (IS_ERR(st->gpio_reset))
    560		return PTR_ERR(st->gpio_reset);
    561
    562	/* Perform a reset */
    563	ret = ad5770r_reset(st);
    564	if (ret)
    565		return ret;
    566
    567	/* Set output range */
    568	ret = ad5770r_channel_config(st);
    569	if (ret)
    570		return ret;
    571
    572	for (i = 0; i < AD5770R_MAX_CHANNELS; i++) {
    573		ret = ad5770r_set_output_mode(st,  &st->output_mode[i], i);
    574		if (ret)
    575			return ret;
    576	}
    577
    578	st->external_res = fwnode_property_read_bool(st->spi->dev.fwnode,
    579						     "adi,external-resistor");
    580
    581	ret = ad5770r_set_reference(st);
    582	if (ret)
    583		return ret;
    584
    585	/* Set outputs off */
    586	ret = regmap_write(st->regmap, AD5770R_CHANNEL_CONFIG, 0x00);
    587	if (ret)
    588		return ret;
    589
    590	ret = regmap_write(st->regmap, AD5770R_CH_ENABLE, 0x00);
    591	if (ret)
    592		return ret;
    593
    594	for (i = 0; i < AD5770R_MAX_CHANNELS; i++)
    595		st->ch_pwr_down[i] = true;
    596
    597	return ret;
    598}
    599
    600static void ad5770r_disable_regulator(void *data)
    601{
    602	struct ad5770r_state *st = data;
    603
    604	regulator_disable(st->vref_reg);
    605}
    606
    607static int ad5770r_probe(struct spi_device *spi)
    608{
    609	struct ad5770r_state *st;
    610	struct iio_dev *indio_dev;
    611	struct regmap *regmap;
    612	int ret;
    613
    614	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
    615	if (!indio_dev)
    616		return -ENOMEM;
    617
    618	st = iio_priv(indio_dev);
    619	spi_set_drvdata(spi, indio_dev);
    620
    621	st->spi = spi;
    622
    623	regmap = devm_regmap_init_spi(spi, &ad5770r_spi_regmap_config);
    624	if (IS_ERR(regmap)) {
    625		dev_err(&spi->dev, "Error initializing spi regmap: %ld\n",
    626			PTR_ERR(regmap));
    627		return PTR_ERR(regmap);
    628	}
    629	st->regmap = regmap;
    630
    631	st->vref_reg = devm_regulator_get_optional(&spi->dev, "vref");
    632	if (!IS_ERR(st->vref_reg)) {
    633		ret = regulator_enable(st->vref_reg);
    634		if (ret) {
    635			dev_err(&spi->dev,
    636				"Failed to enable vref regulators: %d\n", ret);
    637			return ret;
    638		}
    639
    640		ret = devm_add_action_or_reset(&spi->dev,
    641					       ad5770r_disable_regulator,
    642					       st);
    643		if (ret < 0)
    644			return ret;
    645
    646		ret = regulator_get_voltage(st->vref_reg);
    647		if (ret < 0)
    648			return ret;
    649
    650		st->vref = ret / 1000;
    651	} else {
    652		if (PTR_ERR(st->vref_reg) == -ENODEV) {
    653			st->vref = AD5770R_LOW_VREF_mV;
    654			st->internal_ref = true;
    655		} else {
    656			return PTR_ERR(st->vref_reg);
    657		}
    658	}
    659
    660	indio_dev->name = spi_get_device_id(spi)->name;
    661	indio_dev->info = &ad5770r_info;
    662	indio_dev->modes = INDIO_DIRECT_MODE;
    663	indio_dev->channels = ad5770r_channels;
    664	indio_dev->num_channels = ARRAY_SIZE(ad5770r_channels);
    665
    666	ret = ad5770r_init(st);
    667	if (ret < 0) {
    668		dev_err(&spi->dev, "AD5770R init failed\n");
    669		return ret;
    670	}
    671
    672	return devm_iio_device_register(&st->spi->dev, indio_dev);
    673}
    674
    675static const struct of_device_id ad5770r_of_id[] = {
    676	{ .compatible = "adi,ad5770r", },
    677	{},
    678};
    679MODULE_DEVICE_TABLE(of, ad5770r_of_id);
    680
    681static const struct spi_device_id ad5770r_id[] = {
    682	{ "ad5770r", 0 },
    683	{},
    684};
    685MODULE_DEVICE_TABLE(spi, ad5770r_id);
    686
    687static struct spi_driver ad5770r_driver = {
    688	.driver = {
    689		.name = KBUILD_MODNAME,
    690		.of_match_table = ad5770r_of_id,
    691	},
    692	.probe = ad5770r_probe,
    693	.id_table = ad5770r_id,
    694};
    695
    696module_spi_driver(ad5770r_driver);
    697
    698MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>");
    699MODULE_DESCRIPTION("Analog Devices AD5770R IDAC");
    700MODULE_LICENSE("GPL v2");