diff options
Diffstat (limited to 'drivers/iio/dac/ad5592r.c')
| -rw-r--r-- | drivers/iio/dac/ad5592r.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/drivers/iio/dac/ad5592r.c b/drivers/iio/dac/ad5592r.c new file mode 100644 index 000000000000..0b235a2c7359 --- /dev/null +++ b/drivers/iio/dac/ad5592r.c @@ -0,0 +1,164 @@ +/* + * AD5592R Digital <-> Analog converters driver + * + * Copyright 2015-2016 Analog Devices Inc. + * Author: Paul Cercueil <paul.cercueil@analog.com> + * + * Licensed under the GPL-2. + */ + +#include "ad5592r-base.h" + +#include <linux/bitops.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/spi/spi.h> + +#define AD5592R_GPIO_READBACK_EN BIT(10) +#define AD5592R_LDAC_READBACK_EN BIT(6) + +static int ad5592r_spi_wnop_r16(struct ad5592r_state *st, u16 *buf) +{ + struct spi_device *spi = container_of(st->dev, struct spi_device, dev); + struct spi_transfer t = { + .tx_buf = &st->spi_msg_nop, + .rx_buf = buf, + .len = 2 + }; + + st->spi_msg_nop = 0; /* NOP */ + + return spi_sync_transfer(spi, &t, 1); +} + +static int ad5592r_write_dac(struct ad5592r_state *st, unsigned chan, u16 value) +{ + struct spi_device *spi = container_of(st->dev, struct spi_device, dev); + + st->spi_msg = cpu_to_be16(BIT(15) | (chan << 12) | value); + + return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg)); +} + +static int ad5592r_read_adc(struct ad5592r_state *st, unsigned chan, u16 *value) +{ + struct spi_device *spi = container_of(st->dev, struct spi_device, dev); + int ret; + + st->spi_msg = cpu_to_be16((AD5592R_REG_ADC_SEQ << 11) | BIT(chan)); + + ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg)); + if (ret) + return ret; + + /* + * Invalid data: + * See Figure 40. Single-Channel ADC Conversion Sequence + */ + ret = ad5592r_spi_wnop_r16(st, &st->spi_msg); + if (ret) + return ret; + + ret = ad5592r_spi_wnop_r16(st, &st->spi_msg); + if (ret) + return ret; + + *value = be16_to_cpu(st->spi_msg); + + return 0; +} + +static int ad5592r_reg_write(struct ad5592r_state *st, u8 reg, u16 value) +{ + struct spi_device *spi = container_of(st->dev, struct spi_device, dev); + + st->spi_msg = cpu_to_be16((reg << 11) | value); + + return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg)); +} + +static int ad5592r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value) +{ + struct spi_device *spi = container_of(st->dev, struct spi_device, dev); + int ret; + + st->spi_msg = cpu_to_be16((AD5592R_REG_LDAC << 11) | + AD5592R_LDAC_READBACK_EN | (reg << 2)); + + ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg)); + if (ret) + return ret; + + ret = ad5592r_spi_wnop_r16(st, &st->spi_msg); + if (ret) + return ret; + + *value = be16_to_cpu(st->spi_msg); + + return 0; +} + +static int ad5593r_gpio_read(struct ad5592r_state *st, u8 *value) +{ + int ret; + + ret = ad5592r_reg_write(st, AD5592R_REG_GPIO_IN_EN, + AD5592R_GPIO_READBACK_EN | st->gpio_in); + if (ret) + return ret; + + ret = ad5592r_spi_wnop_r16(st, &st->spi_msg); + if (ret) + return ret; + + *value = (u8) be16_to_cpu(st->spi_msg); + + return 0; +} + +static const struct ad5592r_rw_ops ad5592r_rw_ops = { + .write_dac = ad5592r_write_dac, + .read_adc = ad5592r_read_adc, + .reg_write = ad5592r_reg_write, + .reg_read = ad5592r_reg_read, + .gpio_read = ad5593r_gpio_read, +}; + +static int ad5592r_spi_probe(struct spi_device *spi) +{ + const struct spi_device_id *id = spi_get_device_id(spi); + + return ad5592r_probe(&spi->dev, id->name, &ad5592r_rw_ops); +} + +static int ad5592r_spi_remove(struct spi_device *spi) +{ + return ad5592r_remove(&spi->dev); +} + +static const struct spi_device_id ad5592r_spi_ids[] = { + { .name = "ad5592r", }, + {} +}; +MODULE_DEVICE_TABLE(spi, ad5592r_spi_ids); + +static const struct of_device_id ad5592r_of_match[] = { + { .compatible = "adi,ad5592r", }, + {}, +}; +MODULE_DEVICE_TABLE(of, ad5592r_of_match); + +static struct spi_driver ad5592r_spi_driver = { + .driver = { + .name = "ad5592r", + .of_match_table = of_match_ptr(ad5592r_of_match), + }, + .probe = ad5592r_spi_probe, + .remove = ad5592r_spi_remove, + .id_table = ad5592r_spi_ids, +}; +module_spi_driver(ad5592r_spi_driver); + +MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>"); +MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters"); +MODULE_LICENSE("GPL v2"); |