diff options
Diffstat (limited to 'drivers/iio/adc/ad9467.c')
| -rw-r--r-- | drivers/iio/adc/ad9467.c | 422 |
1 files changed, 422 insertions, 0 deletions
diff --git a/drivers/iio/adc/ad9467.c b/drivers/iio/adc/ad9467.c new file mode 100644 index 000000000000..1e8fd83b9bc2 --- /dev/null +++ b/drivers/iio/adc/ad9467.c @@ -0,0 +1,422 @@ +// 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 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_AD9467, +}; + +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 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 ad9467_channels[] = { + AD9467_CHAN(0, 0, 16, 'S'), +}; + +static const struct adi_axi_adc_chip_info ad9467_chip_tbl[] = { + [ID_AD9467] = { + .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), + }, +}; + +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; + struct ad9467_state *st = adi_axi_adc_conv_priv(conv); + unsigned int i, vref_val, vref_mask; + + vref_val = ad9467_spi_read(st->spi, AN877_ADC_REG_VREF); + + switch (info->id) { + case CHIPID_AD9467: + vref_mask = AD9467_REG_VREF_MASK; + break; + default: + vref_mask = 0xFFFF; + break; + } + + vref_val &= 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 int ad9467_setup(struct ad9467_state *st, unsigned int chip_id) +{ + switch (chip_id) { + case CHIPID_AD9467: + st->output_mode = AD9467_DEF_OUTPUT_MODE | + AN877_ADC_OUTPUT_MODE_TWOS_COMPLEMENT; + return 0; + default: + return -EINVAL; + } +} + +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 adi_axi_adc_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; + + id = ad9467_spi_read(spi, AN877_ADC_REG_CHIP_ID); + if (id != conv->chip_info->id) { + dev_err(&spi->dev, "Unrecognized CHIP_ID 0x%X\n", 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; + + return ad9467_setup(st, id); +} + +static const struct of_device_id ad9467_of_match[] = { + { .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"); |