diff options
Diffstat (limited to 'drivers/iio/dac/ti-dac082s085.c')
| -rw-r--r-- | drivers/iio/dac/ti-dac082s085.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/drivers/iio/dac/ti-dac082s085.c b/drivers/iio/dac/ti-dac082s085.c new file mode 100644 index 000000000000..4e1e28339c84 --- /dev/null +++ b/drivers/iio/dac/ti-dac082s085.c @@ -0,0 +1,368 @@ +/* + * ti-dac082s085.c - Texas Instruments 8/10/12-bit 2/4-channel DAC driver + * + * Copyright (C) 2017 KUNBUS GmbH + * + * http://www.ti.com/lit/ds/symlink/dac082s085.pdf + * http://www.ti.com/lit/ds/symlink/dac102s085.pdf + * http://www.ti.com/lit/ds/symlink/dac122s085.pdf + * http://www.ti.com/lit/ds/symlink/dac084s085.pdf + * http://www.ti.com/lit/ds/symlink/dac104s085.pdf + * http://www.ti.com/lit/ds/symlink/dac124s085.pdf + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License (version 2) as + * published by the Free Software Foundation. + */ + +#include <linux/iio/iio.h> +#include <linux/module.h> +#include <linux/regulator/consumer.h> +#include <linux/spi/spi.h> + +enum { dual_8bit, dual_10bit, dual_12bit, quad_8bit, quad_10bit, quad_12bit }; + +struct ti_dac_spec { + u8 num_channels; + u8 resolution; +}; + +static const struct ti_dac_spec ti_dac_spec[] = { + [dual_8bit] = { .num_channels = 2, .resolution = 8 }, + [dual_10bit] = { .num_channels = 2, .resolution = 10 }, + [dual_12bit] = { .num_channels = 2, .resolution = 12 }, + [quad_8bit] = { .num_channels = 4, .resolution = 8 }, + [quad_10bit] = { .num_channels = 4, .resolution = 10 }, + [quad_12bit] = { .num_channels = 4, .resolution = 12 }, +}; + +/** + * struct ti_dac_chip - TI DAC chip + * @lock: protects write sequences + * @vref: regulator generating Vref + * @mesg: SPI message to perform a write + * @xfer: SPI transfer used by @mesg + * @val: cached value of each output + * @powerdown: whether the chip is powered down + * @powerdown_mode: selected by the user + * @resolution: resolution of the chip + * @buf: buffer for @xfer + */ +struct ti_dac_chip { + struct mutex lock; + struct regulator *vref; + struct spi_message mesg; + struct spi_transfer xfer; + u16 val[4]; + bool powerdown; + u8 powerdown_mode; + u8 resolution; + u8 buf[2] ____cacheline_aligned; +}; + +#define WRITE_NOT_UPDATE(chan) (0x00 | (chan) << 6) +#define WRITE_AND_UPDATE(chan) (0x10 | (chan) << 6) +#define WRITE_ALL_UPDATE 0x20 +#define POWERDOWN(mode) (0x30 | ((mode) + 1) << 6) + +static int ti_dac_cmd(struct ti_dac_chip *ti_dac, u8 cmd, u16 val) +{ + u8 shift = 12 - ti_dac->resolution; + + ti_dac->buf[0] = cmd | (val >> (8 - shift)); + ti_dac->buf[1] = (val << shift) & 0xff; + return spi_sync(ti_dac->mesg.spi, &ti_dac->mesg); +} + +static const char * const ti_dac_powerdown_modes[] = { + "2.5kohm_to_gnd", "100kohm_to_gnd", "three_state", +}; + +static int ti_dac_get_powerdown_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + struct ti_dac_chip *ti_dac = iio_priv(indio_dev); + + return ti_dac->powerdown_mode; +} + +static int ti_dac_set_powerdown_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + unsigned int mode) +{ + struct ti_dac_chip *ti_dac = iio_priv(indio_dev); + int ret = 0; + + if (ti_dac->powerdown_mode == mode) + return 0; + + mutex_lock(&ti_dac->lock); + if (ti_dac->powerdown) { + ret = ti_dac_cmd(ti_dac, POWERDOWN(mode), 0); + if (ret) + goto out; + } + ti_dac->powerdown_mode = mode; + +out: + mutex_unlock(&ti_dac->lock); + return ret; +} + +static const struct iio_enum ti_dac_powerdown_mode = { + .items = ti_dac_powerdown_modes, + .num_items = ARRAY_SIZE(ti_dac_powerdown_modes), + .get = ti_dac_get_powerdown_mode, + .set = ti_dac_set_powerdown_mode, +}; + +static ssize_t ti_dac_read_powerdown(struct iio_dev *indio_dev, + uintptr_t private, + const struct iio_chan_spec *chan, + char *buf) +{ + struct ti_dac_chip *ti_dac = iio_priv(indio_dev); + + return sprintf(buf, "%d\n", ti_dac->powerdown); +} + +static ssize_t ti_dac_write_powerdown(struct iio_dev *indio_dev, + uintptr_t private, + const struct iio_chan_spec *chan, + const char *buf, size_t len) +{ + struct ti_dac_chip *ti_dac = iio_priv(indio_dev); + bool powerdown; + int ret; + + ret = strtobool(buf, &powerdown); + if (ret) + return ret; + + if (ti_dac->powerdown == powerdown) + return len; + + mutex_lock(&ti_dac->lock); + if (powerdown) + ret = ti_dac_cmd(ti_dac, POWERDOWN(ti_dac->powerdown_mode), 0); + else + ret = ti_dac_cmd(ti_dac, WRITE_AND_UPDATE(0), ti_dac->val[0]); + if (!ret) + ti_dac->powerdown = powerdown; + mutex_unlock(&ti_dac->lock); + + return ret ? ret : len; +} + +static const struct iio_chan_spec_ext_info ti_dac_ext_info[] = { + { + .name = "powerdown", + .read = ti_dac_read_powerdown, + .write = ti_dac_write_powerdown, + .shared = IIO_SHARED_BY_TYPE, + }, + IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, &ti_dac_powerdown_mode), + IIO_ENUM_AVAILABLE("powerdown_mode", &ti_dac_powerdown_mode), + { }, +}; + +#define TI_DAC_CHANNEL(chan) { \ + .type = IIO_VOLTAGE, \ + .channel = (chan), \ + .address = (chan), \ + .indexed = true, \ + .output = true, \ + .datasheet_name = (const char[]){ 'A' + (chan), 0 }, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .ext_info = ti_dac_ext_info, \ +} + +static const struct iio_chan_spec ti_dac_channels[] = { + TI_DAC_CHANNEL(0), + TI_DAC_CHANNEL(1), + TI_DAC_CHANNEL(2), + TI_DAC_CHANNEL(3), +}; + +static int ti_dac_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct ti_dac_chip *ti_dac = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + *val = ti_dac->val[chan->channel]; + ret = IIO_VAL_INT; + break; + + case IIO_CHAN_INFO_SCALE: + ret = regulator_get_voltage(ti_dac->vref); + if (ret < 0) + return ret; + + *val = ret / 1000; + *val2 = ti_dac->resolution; + ret = IIO_VAL_FRACTIONAL_LOG2; + break; + + default: + ret = -EINVAL; + } + + return ret; +} + +static int ti_dac_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct ti_dac_chip *ti_dac = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (ti_dac->val[chan->channel] == val) + return 0; + + if (val >= (1 << ti_dac->resolution) || val < 0) + return -EINVAL; + + if (ti_dac->powerdown) + return -EBUSY; + + mutex_lock(&ti_dac->lock); + ret = ti_dac_cmd(ti_dac, WRITE_AND_UPDATE(chan->channel), val); + if (!ret) + ti_dac->val[chan->channel] = val; + mutex_unlock(&ti_dac->lock); + break; + + default: + ret = -EINVAL; + } + + return ret; +} + +static int ti_dac_write_raw_get_fmt(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, long mask) +{ + return IIO_VAL_INT; +} + +static const struct iio_info ti_dac_info = { + .read_raw = ti_dac_read_raw, + .write_raw = ti_dac_write_raw, + .write_raw_get_fmt = ti_dac_write_raw_get_fmt, +}; + +static int ti_dac_probe(struct spi_device *spi) +{ + struct device *dev = &spi->dev; + const struct ti_dac_spec *spec; + struct ti_dac_chip *ti_dac; + struct iio_dev *indio_dev; + int ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*ti_dac)); + if (!indio_dev) + return -ENOMEM; + + indio_dev->dev.parent = dev; + indio_dev->info = &ti_dac_info; + indio_dev->name = spi->modalias; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = ti_dac_channels; + spi_set_drvdata(spi, indio_dev); + + ti_dac = iio_priv(indio_dev); + ti_dac->xfer.tx_buf = &ti_dac->buf; + ti_dac->xfer.len = sizeof(ti_dac->buf); + spi_message_init_with_transfers(&ti_dac->mesg, &ti_dac->xfer, 1); + ti_dac->mesg.spi = spi; + + spec = &ti_dac_spec[spi_get_device_id(spi)->driver_data]; + indio_dev->num_channels = spec->num_channels; + ti_dac->resolution = spec->resolution; + + ti_dac->vref = devm_regulator_get(dev, "vref"); + if (IS_ERR(ti_dac->vref)) + return PTR_ERR(ti_dac->vref); + + ret = regulator_enable(ti_dac->vref); + if (ret < 0) + return ret; + + mutex_init(&ti_dac->lock); + + ret = ti_dac_cmd(ti_dac, WRITE_ALL_UPDATE, 0); + if (ret) { + dev_err(dev, "failed to initialize outputs to 0\n"); + goto err; + } + + ret = iio_device_register(indio_dev); + if (ret) + goto err; + + return 0; + +err: + mutex_destroy(&ti_dac->lock); + regulator_disable(ti_dac->vref); + return ret; +} + +static int ti_dac_remove(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + struct ti_dac_chip *ti_dac = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + mutex_destroy(&ti_dac->lock); + regulator_disable(ti_dac->vref); + + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id ti_dac_of_id[] = { + { .compatible = "ti,dac082s085" }, + { .compatible = "ti,dac102s085" }, + { .compatible = "ti,dac122s085" }, + { .compatible = "ti,dac084s085" }, + { .compatible = "ti,dac104s085" }, + { .compatible = "ti,dac124s085" }, + { } +}; +MODULE_DEVICE_TABLE(of, ti_dac_of_id); +#endif + +static const struct spi_device_id ti_dac_spi_id[] = { + { "dac082s085", dual_8bit }, + { "dac102s085", dual_10bit }, + { "dac122s085", dual_12bit }, + { "dac084s085", quad_8bit }, + { "dac104s085", quad_10bit }, + { "dac124s085", quad_12bit }, + { } +}; +MODULE_DEVICE_TABLE(spi, ti_dac_spi_id); + +static struct spi_driver ti_dac_driver = { + .driver = { + .name = "ti-dac082s085", + .of_match_table = of_match_ptr(ti_dac_of_id), + }, + .probe = ti_dac_probe, + .remove = ti_dac_remove, + .id_table = ti_dac_spi_id, +}; +module_spi_driver(ti_dac_driver); + +MODULE_AUTHOR("Lukas Wunner <lukas@wunner.de>"); +MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 2/4-channel DAC driver"); +MODULE_LICENSE("GPL v2"); |