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linux/drivers/iio/adc/ad9467.c
Michael Hennerich eb61343dfd iio: adc: ad9467: add support for AD9265 high-speed ADC 
The AD9265 is a 16-bit, 125 MSPS analog-to-digital converter (ADC). The
AD9265 is designed to support communications applications where high
performance combined with low cost, small size, and versatility is
desired.

The ADC core features a multistage, differential pipelined architecture
with integrated output error correction logic to provide 16-bit accuracy at
125 MSPS data rates and guarantees no missing codes over the full operating
temperature range.

The ADC features a wide bandwidth differential sample-and-hold analog input
amplifier supporting a variety of user-selectable input ranges. It is
suitable for multiplexed systems that switch full-scale voltage levels in
successive channels and for sampling single-channel inputs at frequencies
well beyond the Nyquist rate. Combined with power and cost savings over
previously available ADCs, the AD9265 is suitable for applications in
communications, instrumentation and medical imaging.

Link: https://www.analog.com/media/en/technical-documentation/data-sheets/AD9434.pdf

The driver supports the same register set as the AD9467, so the support for
this chip is added to the 'ad9467' driver.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20200924080518.96410-4-alexandru.ardelean@analog.com
2020-09-29 17:27:07 +01:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Analog Devices AD9467 SPI ADC driver
*
* Copyright 2012-2020 Analog Devices Inc.
*/
#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/of_device.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/clk.h>
#include <linux/iio/adc/adi-axi-adc.h>
/*
* ADI High-Speed ADC common spi interface registers
* See Application-Note AN-877:
* https://www.analog.com/media/en/technical-documentation/application-notes/AN-877.pdf
*/
#define AN877_ADC_REG_CHIP_PORT_CONF 0x00
#define AN877_ADC_REG_CHIP_ID 0x01
#define AN877_ADC_REG_CHIP_GRADE 0x02
#define AN877_ADC_REG_CHAN_INDEX 0x05
#define AN877_ADC_REG_TRANSFER 0xFF
#define AN877_ADC_REG_MODES 0x08
#define AN877_ADC_REG_TEST_IO 0x0D
#define AN877_ADC_REG_ADC_INPUT 0x0F
#define AN877_ADC_REG_OFFSET 0x10
#define AN877_ADC_REG_OUTPUT_MODE 0x14
#define AN877_ADC_REG_OUTPUT_ADJUST 0x15
#define AN877_ADC_REG_OUTPUT_PHASE 0x16
#define AN877_ADC_REG_OUTPUT_DELAY 0x17
#define AN877_ADC_REG_VREF 0x18
#define AN877_ADC_REG_ANALOG_INPUT 0x2C
/* AN877_ADC_REG_TEST_IO */
#define AN877_ADC_TESTMODE_OFF 0x0
#define AN877_ADC_TESTMODE_MIDSCALE_SHORT 0x1
#define AN877_ADC_TESTMODE_POS_FULLSCALE 0x2
#define AN877_ADC_TESTMODE_NEG_FULLSCALE 0x3
#define AN877_ADC_TESTMODE_ALT_CHECKERBOARD 0x4
#define AN877_ADC_TESTMODE_PN23_SEQ 0x5
#define AN877_ADC_TESTMODE_PN9_SEQ 0x6
#define AN877_ADC_TESTMODE_ONE_ZERO_TOGGLE 0x7
#define AN877_ADC_TESTMODE_USER 0x8
#define AN877_ADC_TESTMODE_BIT_TOGGLE 0x9
#define AN877_ADC_TESTMODE_SYNC 0xA
#define AN877_ADC_TESTMODE_ONE_BIT_HIGH 0xB
#define AN877_ADC_TESTMODE_MIXED_BIT_FREQUENCY 0xC
#define AN877_ADC_TESTMODE_RAMP 0xF
/* AN877_ADC_REG_TRANSFER */
#define AN877_ADC_TRANSFER_SYNC 0x1
/* AN877_ADC_REG_OUTPUT_MODE */
#define AN877_ADC_OUTPUT_MODE_OFFSET_BINARY 0x0
#define AN877_ADC_OUTPUT_MODE_TWOS_COMPLEMENT 0x1
#define AN877_ADC_OUTPUT_MODE_GRAY_CODE 0x2
/* AN877_ADC_REG_OUTPUT_PHASE */
#define AN877_ADC_OUTPUT_EVEN_ODD_MODE_EN 0x20
#define AN877_ADC_INVERT_DCO_CLK 0x80
/* AN877_ADC_REG_OUTPUT_DELAY */
#define AN877_ADC_DCO_DELAY_ENABLE 0x80
/*
* Analog Devices AD9265 16-Bit, 125/105/80 MSPS ADC
*/
#define CHIPID_AD9265 0x64
#define AD9265_DEF_OUTPUT_MODE 0x40
#define AD9265_REG_VREF_MASK 0xC0
/*
* Analog Devices AD9434 12-Bit, 370/500 MSPS ADC
*/
#define CHIPID_AD9434 0x6A
#define AD9434_DEF_OUTPUT_MODE 0x00
#define AD9434_REG_VREF_MASK 0xC0
/*
* Analog Devices AD9467 16-Bit, 200/250 MSPS ADC
*/
#define CHIPID_AD9467 0x50
#define AD9467_DEF_OUTPUT_MODE 0x08
#define AD9467_REG_VREF_MASK 0x0F
enum {
ID_AD9265,
ID_AD9434,
ID_AD9467,
};
struct ad9467_chip_info {
struct adi_axi_adc_chip_info axi_adc_info;
unsigned int default_output_mode;
unsigned int vref_mask;
};
#define to_ad9467_chip_info(_info) \
container_of(_info, struct ad9467_chip_info, axi_adc_info)
struct ad9467_state {
struct spi_device *spi;
struct clk *clk;
unsigned int output_mode;
struct gpio_desc *pwrdown_gpio;
struct gpio_desc *reset_gpio;
};
static int ad9467_spi_read(struct spi_device *spi, unsigned int reg)
{
unsigned char tbuf[2], rbuf[1];
int ret;
tbuf[0] = 0x80 | (reg >> 8);
tbuf[1] = reg & 0xFF;
ret = spi_write_then_read(spi,
tbuf, ARRAY_SIZE(tbuf),
rbuf, ARRAY_SIZE(rbuf));
if (ret < 0)
return ret;
return rbuf[0];
}
static int ad9467_spi_write(struct spi_device *spi, unsigned int reg,
unsigned int val)
{
unsigned char buf[3];
buf[0] = reg >> 8;
buf[1] = reg & 0xFF;
buf[2] = val;
return spi_write(spi, buf, ARRAY_SIZE(buf));
}
static int ad9467_reg_access(struct adi_axi_adc_conv *conv, unsigned int reg,
unsigned int writeval, unsigned int *readval)
{
struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
struct spi_device *spi = st->spi;
int ret;
if (readval == NULL) {
ret = ad9467_spi_write(spi, reg, writeval);
ad9467_spi_write(spi, AN877_ADC_REG_TRANSFER,
AN877_ADC_TRANSFER_SYNC);
return ret;
}
ret = ad9467_spi_read(spi, reg);
if (ret < 0)
return ret;
*readval = ret;
return 0;
}
static const unsigned int ad9265_scale_table[][2] = {
{1250, 0x00}, {1500, 0x40}, {1750, 0x80}, {2000, 0xC0},
};
static const unsigned int ad9434_scale_table[][2] = {
{1600, 0x1C}, {1580, 0x1D}, {1550, 0x1E}, {1520, 0x1F}, {1500, 0x00},
{1470, 0x01}, {1440, 0x02}, {1420, 0x03}, {1390, 0x04}, {1360, 0x05},
{1340, 0x06}, {1310, 0x07}, {1280, 0x08}, {1260, 0x09}, {1230, 0x0A},
{1200, 0x0B}, {1180, 0x0C},
};
static const unsigned int ad9467_scale_table[][2] = {
{2000, 0}, {2100, 6}, {2200, 7},
{2300, 8}, {2400, 9}, {2500, 10},
};
static void __ad9467_get_scale(struct adi_axi_adc_conv *conv, int index,
unsigned int *val, unsigned int *val2)
{
const struct adi_axi_adc_chip_info *info = conv->chip_info;
const struct iio_chan_spec *chan = &info->channels[0];
unsigned int tmp;
tmp = (info->scale_table[index][0] * 1000000ULL) >>
chan->scan_type.realbits;
*val = tmp / 1000000;
*val2 = tmp % 1000000;
}
#define AD9467_CHAN(_chan, _si, _bits, _sign) \
{ \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = _chan, \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_SAMP_FREQ), \
.scan_index = _si, \
.scan_type = { \
.sign = _sign, \
.realbits = _bits, \
.storagebits = 16, \
}, \
}
static const struct iio_chan_spec ad9434_channels[] = {
AD9467_CHAN(0, 0, 12, 'S'),
};
static const struct iio_chan_spec ad9467_channels[] = {
AD9467_CHAN(0, 0, 16, 'S'),
};
static const struct ad9467_chip_info ad9467_chip_tbl[] = {
[ID_AD9265] = {
.axi_adc_info = {
.id = CHIPID_AD9265,
.max_rate = 125000000UL,
.scale_table = ad9265_scale_table,
.num_scales = ARRAY_SIZE(ad9265_scale_table),
.channels = ad9467_channels,
.num_channels = ARRAY_SIZE(ad9467_channels),
},
.default_output_mode = AD9265_DEF_OUTPUT_MODE,
.vref_mask = AD9265_REG_VREF_MASK,
},
[ID_AD9434] = {
.axi_adc_info = {
.id = CHIPID_AD9434,
.max_rate = 500000000UL,
.scale_table = ad9434_scale_table,
.num_scales = ARRAY_SIZE(ad9434_scale_table),
.channels = ad9434_channels,
.num_channels = ARRAY_SIZE(ad9434_channels),
},
.default_output_mode = AD9434_DEF_OUTPUT_MODE,
.vref_mask = AD9434_REG_VREF_MASK,
},
[ID_AD9467] = {
.axi_adc_info = {
.id = CHIPID_AD9467,
.max_rate = 250000000UL,
.scale_table = ad9467_scale_table,
.num_scales = ARRAY_SIZE(ad9467_scale_table),
.channels = ad9467_channels,
.num_channels = ARRAY_SIZE(ad9467_channels),
},
.default_output_mode = AD9467_DEF_OUTPUT_MODE,
.vref_mask = AD9467_REG_VREF_MASK,
},
};
static int ad9467_get_scale(struct adi_axi_adc_conv *conv, int *val, int *val2)
{
const struct adi_axi_adc_chip_info *info = conv->chip_info;
const struct ad9467_chip_info *info1 = to_ad9467_chip_info(info);
struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
unsigned int i, vref_val;
vref_val = ad9467_spi_read(st->spi, AN877_ADC_REG_VREF);
vref_val &= info1->vref_mask;
for (i = 0; i < info->num_scales; i++) {
if (vref_val == info->scale_table[i][1])
break;
}
if (i == info->num_scales)
return -ERANGE;
__ad9467_get_scale(conv, i, val, val2);
return IIO_VAL_INT_PLUS_MICRO;
}
static int ad9467_set_scale(struct adi_axi_adc_conv *conv, int val, int val2)
{
const struct adi_axi_adc_chip_info *info = conv->chip_info;
struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
unsigned int scale_val[2];
unsigned int i;
if (val != 0)
return -EINVAL;
for (i = 0; i < info->num_scales; i++) {
__ad9467_get_scale(conv, i, &scale_val[0], &scale_val[1]);
if (scale_val[0] != val || scale_val[1] != val2)
continue;
ad9467_spi_write(st->spi, AN877_ADC_REG_VREF,
info->scale_table[i][1]);
ad9467_spi_write(st->spi, AN877_ADC_REG_TRANSFER,
AN877_ADC_TRANSFER_SYNC);
return 0;
}
return -EINVAL;
}
static int ad9467_read_raw(struct adi_axi_adc_conv *conv,
struct iio_chan_spec const *chan,
int *val, int *val2, long m)
{
struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
switch (m) {
case IIO_CHAN_INFO_SCALE:
return ad9467_get_scale(conv, val, val2);
case IIO_CHAN_INFO_SAMP_FREQ:
*val = clk_get_rate(st->clk);
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int ad9467_write_raw(struct adi_axi_adc_conv *conv,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
const struct adi_axi_adc_chip_info *info = conv->chip_info;
struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
long r_clk;
switch (mask) {
case IIO_CHAN_INFO_SCALE:
return ad9467_set_scale(conv, val, val2);
case IIO_CHAN_INFO_SAMP_FREQ:
r_clk = clk_round_rate(st->clk, val);
if (r_clk < 0 || r_clk > info->max_rate) {
dev_warn(&st->spi->dev,
"Error setting ADC sample rate %ld", r_clk);
return -EINVAL;
}
return clk_set_rate(st->clk, r_clk);
default:
return -EINVAL;
}
}
static int ad9467_outputmode_set(struct spi_device *spi, unsigned int mode)
{
int ret;
ret = ad9467_spi_write(spi, AN877_ADC_REG_OUTPUT_MODE, mode);
if (ret < 0)
return ret;
return ad9467_spi_write(spi, AN877_ADC_REG_TRANSFER,
AN877_ADC_TRANSFER_SYNC);
}
static int ad9467_preenable_setup(struct adi_axi_adc_conv *conv)
{
struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
return ad9467_outputmode_set(st->spi, st->output_mode);
}
static void ad9467_clk_disable(void *data)
{
struct ad9467_state *st = data;
clk_disable_unprepare(st->clk);
}
static int ad9467_probe(struct spi_device *spi)
{
const struct ad9467_chip_info *info;
struct adi_axi_adc_conv *conv;
struct ad9467_state *st;
unsigned int id;
int ret;
info = of_device_get_match_data(&spi->dev);
if (!info)
return -ENODEV;
conv = devm_adi_axi_adc_conv_register(&spi->dev, sizeof(*st));
if (IS_ERR(conv))
return PTR_ERR(conv);
st = adi_axi_adc_conv_priv(conv);
st->spi = spi;
st->clk = devm_clk_get(&spi->dev, "adc-clk");
if (IS_ERR(st->clk))
return PTR_ERR(st->clk);
ret = clk_prepare_enable(st->clk);
if (ret < 0)
return ret;
ret = devm_add_action_or_reset(&spi->dev, ad9467_clk_disable, st);
if (ret)
return ret;
st->pwrdown_gpio = devm_gpiod_get_optional(&spi->dev, "powerdown",
GPIOD_OUT_LOW);
if (IS_ERR(st->pwrdown_gpio))
return PTR_ERR(st->pwrdown_gpio);
st->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset",
GPIOD_OUT_LOW);
if (IS_ERR(st->reset_gpio))
return PTR_ERR(st->reset_gpio);
if (st->reset_gpio) {
udelay(1);
ret = gpiod_direction_output(st->reset_gpio, 1);
if (ret)
return ret;
mdelay(10);
}
spi_set_drvdata(spi, st);
conv->chip_info = &info->axi_adc_info;
id = ad9467_spi_read(spi, AN877_ADC_REG_CHIP_ID);
if (id != conv->chip_info->id) {
dev_err(&spi->dev, "Mismatch CHIP_ID, got 0x%X, expected 0x%X\n",
id, conv->chip_info->id);
return -ENODEV;
}
conv->reg_access = ad9467_reg_access;
conv->write_raw = ad9467_write_raw;
conv->read_raw = ad9467_read_raw;
conv->preenable_setup = ad9467_preenable_setup;
st->output_mode = info->default_output_mode |
AN877_ADC_OUTPUT_MODE_TWOS_COMPLEMENT;
return 0;
}
static const struct of_device_id ad9467_of_match[] = {
{ .compatible = "adi,ad9265", .data = &ad9467_chip_tbl[ID_AD9265], },
{ .compatible = "adi,ad9434", .data = &ad9467_chip_tbl[ID_AD9434], },
{ .compatible = "adi,ad9467", .data = &ad9467_chip_tbl[ID_AD9467], },
{}
};
MODULE_DEVICE_TABLE(of, ad9467_of_match);
static struct spi_driver ad9467_driver = {
.driver = {
.name = "ad9467",
.of_match_table = ad9467_of_match,
},
.probe = ad9467_probe,
};
module_spi_driver(ad9467_driver);
MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD9467 ADC driver");
MODULE_LICENSE("GPL v2");
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