forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
266 lines
6.6 KiB
266 lines
6.6 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* TI tlc4541 ADC Driver |
|
* |
|
* Copyright (C) 2017 Phil Reid |
|
* |
|
* Datasheets can be found here: |
|
* https://www.ti.com/lit/gpn/tlc3541 |
|
* https://www.ti.com/lit/gpn/tlc4541 |
|
* |
|
* The tlc4541 requires 24 clock cycles to start a transfer. |
|
* Conversion then takes 2.94us to complete before data is ready |
|
* Data is returned MSB first. |
|
*/ |
|
|
|
#include <linux/delay.h> |
|
#include <linux/device.h> |
|
#include <linux/err.h> |
|
#include <linux/interrupt.h> |
|
#include <linux/iio/iio.h> |
|
#include <linux/iio/sysfs.h> |
|
#include <linux/iio/buffer.h> |
|
#include <linux/iio/trigger_consumer.h> |
|
#include <linux/iio/triggered_buffer.h> |
|
#include <linux/kernel.h> |
|
#include <linux/module.h> |
|
#include <linux/mod_devicetable.h> |
|
#include <linux/regulator/consumer.h> |
|
#include <linux/slab.h> |
|
#include <linux/spi/spi.h> |
|
#include <linux/sysfs.h> |
|
|
|
struct tlc4541_state { |
|
struct spi_device *spi; |
|
struct regulator *reg; |
|
struct spi_transfer scan_single_xfer[3]; |
|
struct spi_message scan_single_msg; |
|
|
|
/* |
|
* DMA (thus cache coherency maintenance) requires the |
|
* transfer buffers to live in their own cache lines. |
|
* 2 bytes data + 6 bytes padding + 8 bytes timestamp when |
|
* call iio_push_to_buffers_with_timestamp. |
|
*/ |
|
__be16 rx_buf[8] ____cacheline_aligned; |
|
}; |
|
|
|
struct tlc4541_chip_info { |
|
const struct iio_chan_spec *channels; |
|
unsigned int num_channels; |
|
}; |
|
|
|
enum tlc4541_id { |
|
TLC3541, |
|
TLC4541, |
|
}; |
|
|
|
#define TLC4541_V_CHAN(bits, bitshift) { \ |
|
.type = IIO_VOLTAGE, \ |
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
|
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ |
|
.scan_type = { \ |
|
.sign = 'u', \ |
|
.realbits = (bits), \ |
|
.storagebits = 16, \ |
|
.shift = (bitshift), \ |
|
.endianness = IIO_BE, \ |
|
}, \ |
|
} |
|
|
|
#define DECLARE_TLC4541_CHANNELS(name, bits, bitshift) \ |
|
const struct iio_chan_spec name ## _channels[] = { \ |
|
TLC4541_V_CHAN(bits, bitshift), \ |
|
IIO_CHAN_SOFT_TIMESTAMP(1), \ |
|
} |
|
|
|
static DECLARE_TLC4541_CHANNELS(tlc3541, 14, 2); |
|
static DECLARE_TLC4541_CHANNELS(tlc4541, 16, 0); |
|
|
|
static const struct tlc4541_chip_info tlc4541_chip_info[] = { |
|
[TLC3541] = { |
|
.channels = tlc3541_channels, |
|
.num_channels = ARRAY_SIZE(tlc3541_channels), |
|
}, |
|
[TLC4541] = { |
|
.channels = tlc4541_channels, |
|
.num_channels = ARRAY_SIZE(tlc4541_channels), |
|
}, |
|
}; |
|
|
|
static irqreturn_t tlc4541_trigger_handler(int irq, void *p) |
|
{ |
|
struct iio_poll_func *pf = p; |
|
struct iio_dev *indio_dev = pf->indio_dev; |
|
struct tlc4541_state *st = iio_priv(indio_dev); |
|
int ret; |
|
|
|
ret = spi_sync(st->spi, &st->scan_single_msg); |
|
if (ret < 0) |
|
goto done; |
|
|
|
iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf, |
|
iio_get_time_ns(indio_dev)); |
|
|
|
done: |
|
iio_trigger_notify_done(indio_dev->trig); |
|
return IRQ_HANDLED; |
|
} |
|
|
|
static int tlc4541_get_range(struct tlc4541_state *st) |
|
{ |
|
int vref; |
|
|
|
vref = regulator_get_voltage(st->reg); |
|
if (vref < 0) |
|
return vref; |
|
|
|
vref /= 1000; |
|
|
|
return vref; |
|
} |
|
|
|
static int tlc4541_read_raw(struct iio_dev *indio_dev, |
|
struct iio_chan_spec const *chan, |
|
int *val, |
|
int *val2, |
|
long m) |
|
{ |
|
int ret = 0; |
|
struct tlc4541_state *st = iio_priv(indio_dev); |
|
|
|
switch (m) { |
|
case IIO_CHAN_INFO_RAW: |
|
ret = iio_device_claim_direct_mode(indio_dev); |
|
if (ret) |
|
return ret; |
|
ret = spi_sync(st->spi, &st->scan_single_msg); |
|
iio_device_release_direct_mode(indio_dev); |
|
if (ret < 0) |
|
return ret; |
|
*val = be16_to_cpu(st->rx_buf[0]); |
|
*val = *val >> chan->scan_type.shift; |
|
*val &= GENMASK(chan->scan_type.realbits - 1, 0); |
|
return IIO_VAL_INT; |
|
case IIO_CHAN_INFO_SCALE: |
|
ret = tlc4541_get_range(st); |
|
if (ret < 0) |
|
return ret; |
|
*val = ret; |
|
*val2 = chan->scan_type.realbits; |
|
return IIO_VAL_FRACTIONAL_LOG2; |
|
} |
|
return -EINVAL; |
|
} |
|
|
|
static const struct iio_info tlc4541_info = { |
|
.read_raw = &tlc4541_read_raw, |
|
}; |
|
|
|
static int tlc4541_probe(struct spi_device *spi) |
|
{ |
|
struct tlc4541_state *st; |
|
struct iio_dev *indio_dev; |
|
const struct tlc4541_chip_info *info; |
|
int ret; |
|
int8_t device_init = 0; |
|
|
|
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); |
|
if (indio_dev == NULL) |
|
return -ENOMEM; |
|
|
|
st = iio_priv(indio_dev); |
|
|
|
spi_set_drvdata(spi, indio_dev); |
|
|
|
st->spi = spi; |
|
|
|
info = &tlc4541_chip_info[spi_get_device_id(spi)->driver_data]; |
|
|
|
indio_dev->name = spi_get_device_id(spi)->name; |
|
indio_dev->modes = INDIO_DIRECT_MODE; |
|
indio_dev->channels = info->channels; |
|
indio_dev->num_channels = info->num_channels; |
|
indio_dev->info = &tlc4541_info; |
|
|
|
/* perform reset */ |
|
spi_write(spi, &device_init, 1); |
|
|
|
/* Setup default message */ |
|
st->scan_single_xfer[0].rx_buf = &st->rx_buf[0]; |
|
st->scan_single_xfer[0].len = 3; |
|
st->scan_single_xfer[1].delay.value = 3; |
|
st->scan_single_xfer[1].delay.unit = SPI_DELAY_UNIT_NSECS; |
|
st->scan_single_xfer[2].rx_buf = &st->rx_buf[0]; |
|
st->scan_single_xfer[2].len = 2; |
|
|
|
spi_message_init_with_transfers(&st->scan_single_msg, |
|
st->scan_single_xfer, 3); |
|
|
|
st->reg = devm_regulator_get(&spi->dev, "vref"); |
|
if (IS_ERR(st->reg)) |
|
return PTR_ERR(st->reg); |
|
|
|
ret = regulator_enable(st->reg); |
|
if (ret) |
|
return ret; |
|
|
|
ret = iio_triggered_buffer_setup(indio_dev, NULL, |
|
&tlc4541_trigger_handler, NULL); |
|
if (ret) |
|
goto error_disable_reg; |
|
|
|
ret = iio_device_register(indio_dev); |
|
if (ret) |
|
goto error_cleanup_buffer; |
|
|
|
return 0; |
|
|
|
error_cleanup_buffer: |
|
iio_triggered_buffer_cleanup(indio_dev); |
|
error_disable_reg: |
|
regulator_disable(st->reg); |
|
|
|
return ret; |
|
} |
|
|
|
static int tlc4541_remove(struct spi_device *spi) |
|
{ |
|
struct iio_dev *indio_dev = spi_get_drvdata(spi); |
|
struct tlc4541_state *st = iio_priv(indio_dev); |
|
|
|
iio_device_unregister(indio_dev); |
|
iio_triggered_buffer_cleanup(indio_dev); |
|
regulator_disable(st->reg); |
|
|
|
return 0; |
|
} |
|
|
|
static const struct of_device_id tlc4541_dt_ids[] = { |
|
{ .compatible = "ti,tlc3541", }, |
|
{ .compatible = "ti,tlc4541", }, |
|
{} |
|
}; |
|
MODULE_DEVICE_TABLE(of, tlc4541_dt_ids); |
|
|
|
static const struct spi_device_id tlc4541_id[] = { |
|
{"tlc3541", TLC3541}, |
|
{"tlc4541", TLC4541}, |
|
{} |
|
}; |
|
MODULE_DEVICE_TABLE(spi, tlc4541_id); |
|
|
|
static struct spi_driver tlc4541_driver = { |
|
.driver = { |
|
.name = "tlc4541", |
|
.of_match_table = tlc4541_dt_ids, |
|
}, |
|
.probe = tlc4541_probe, |
|
.remove = tlc4541_remove, |
|
.id_table = tlc4541_id, |
|
}; |
|
module_spi_driver(tlc4541_driver); |
|
|
|
MODULE_AUTHOR("Phil Reid <[email protected]>"); |
|
MODULE_DESCRIPTION("Texas Instruments TLC4541 ADC"); |
|
MODULE_LICENSE("GPL v2");
|
|
|