iio: adc: tlc4541: add support for TI tlc4541 adc
This adds TI's tlc4541 16-bit ADC driver. Which is a single channel ADC. Supports raw and trigger buffer access. Also supports the tlc3541 14-bit device, which has not been tested. Implementation of the tlc3541 is fairly straight forward thou. Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Phil Reid <preid@electromag.com.au> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Phil Reid
Jonathan Cameron
parent
0dbe71c274
commit
ac2bec9d58
@ -612,6 +612,18 @@ config TI_AM335X_ADC
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To compile this driver as a module, choose M here: the module will be
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called ti_am335x_adc.
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config TI_TLC4541
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tristate "Texas Instruments TLC4541 ADC driver"
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depends on SPI
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select IIO_BUFFER
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select IIO_TRIGGERED_BUFFER
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help
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Say yes here to build support for Texas Instruments TLC4541 / TLC3541
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ADC chips.
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This driver can also be built as a module. If so, the module will be
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called ti-tlc4541.
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config TWL4030_MADC
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tristate "TWL4030 MADC (Monitoring A/D Converter)"
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depends on TWL4030_CORE
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@ -56,6 +56,7 @@ obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
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obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o
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obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
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obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
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obj-$(CONFIG_TI_TLC4541) += ti-tlc4541.o
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obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o
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obj-$(CONFIG_TWL6030_GPADC) += twl6030-gpadc.o
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obj-$(CONFIG_VF610_ADC) += vf610_adc.o
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@ -30,7 +30,6 @@
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#define MAX11100_LSB_DIV (1 << 16)
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struct max11100_state {
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const struct max11100_chip_desc *desc;
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struct regulator *vref_reg;
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struct spi_device *spi;
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@ -49,14 +48,6 @@ static struct iio_chan_spec max11100_channels[] = {
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},
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};
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static struct max11100_chip_desc {
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unsigned int num_chan;
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const struct iio_chan_spec *channels;
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} max11100_desc = {
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.num_chan = ARRAY_SIZE(max11100_channels),
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.channels = max11100_channels,
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};
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static int max11100_read_single(struct iio_dev *indio_dev, int *val)
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{
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int ret;
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@ -127,15 +118,14 @@ static int max11100_probe(struct spi_device *spi)
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state = iio_priv(indio_dev);
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state->spi = spi;
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state->desc = &max11100_desc;
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indio_dev->dev.parent = &spi->dev;
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indio_dev->dev.of_node = spi->dev.of_node;
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indio_dev->name = "max11100";
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indio_dev->info = &max11100_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = state->desc->channels;
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indio_dev->num_channels = state->desc->num_chan;
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indio_dev->channels = max11100_channels,
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indio_dev->num_channels = ARRAY_SIZE(max11100_channels),
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state->vref_reg = devm_regulator_get(&spi->dev, "vref");
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if (IS_ERR(state->vref_reg))
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@ -162,9 +152,8 @@ static int max11100_remove(struct spi_device *spi)
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struct iio_dev *indio_dev = spi_get_drvdata(spi);
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struct max11100_state *state = iio_priv(indio_dev);
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regulator_disable(state->vref_reg);
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iio_device_unregister(indio_dev);
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regulator_disable(state->vref_reg);
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return 0;
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}
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271
drivers/iio/adc/ti-tlc4541.c
Normal file
271
drivers/iio/adc/ti-tlc4541.c
Normal file
@ -0,0 +1,271 @@
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/*
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* TI tlc4541 ADC Driver
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*
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* Copyright (C) 2017 Phil Reid
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*
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* Datasheets can be found here:
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* http://www.ti.com/lit/gpn/tlc3541
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* http://www.ti.com/lit/gpn/tlc4541
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* The tlc4541 requires 24 clock cycles to start a transfer.
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* Conversion then takes 2.94us to complete before data is ready
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* Data is returned MSB first.
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*/
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#include <linux/delay.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/interrupt.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include <linux/iio/buffer.h>
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#include <linux/iio/trigger_consumer.h>
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#include <linux/iio/triggered_buffer.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/regulator/consumer.h>
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#include <linux/slab.h>
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#include <linux/spi/spi.h>
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#include <linux/sysfs.h>
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struct tlc4541_state {
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struct spi_device *spi;
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struct regulator *reg;
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struct spi_transfer scan_single_xfer[3];
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struct spi_message scan_single_msg;
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/*
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* DMA (thus cache coherency maintenance) requires the
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* transfer buffers to live in their own cache lines.
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* 2 bytes data + 6 bytes padding + 8 bytes timestamp when
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* call iio_push_to_buffers_with_timestamp.
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*/
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__be16 rx_buf[8] ____cacheline_aligned;
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};
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struct tlc4541_chip_info {
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const struct iio_chan_spec *channels;
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unsigned int num_channels;
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};
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enum tlc4541_id {
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TLC3541,
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TLC4541,
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};
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#define TLC4541_V_CHAN(bits, bitshift) { \
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.type = IIO_VOLTAGE, \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
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.scan_type = { \
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.sign = 'u', \
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.realbits = (bits), \
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.storagebits = 16, \
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.shift = (bitshift), \
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.endianness = IIO_BE, \
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}, \
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}
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#define DECLARE_TLC4541_CHANNELS(name, bits, bitshift) \
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const struct iio_chan_spec name ## _channels[] = { \
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TLC4541_V_CHAN(bits, bitshift), \
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IIO_CHAN_SOFT_TIMESTAMP(1), \
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}
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static DECLARE_TLC4541_CHANNELS(tlc3541, 14, 2);
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static DECLARE_TLC4541_CHANNELS(tlc4541, 16, 0);
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static const struct tlc4541_chip_info tlc4541_chip_info[] = {
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[TLC3541] = {
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.channels = tlc3541_channels,
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.num_channels = ARRAY_SIZE(tlc3541_channels),
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},
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[TLC4541] = {
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.channels = tlc4541_channels,
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.num_channels = ARRAY_SIZE(tlc4541_channels),
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},
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};
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static irqreturn_t tlc4541_trigger_handler(int irq, void *p)
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{
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struct iio_poll_func *pf = p;
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struct iio_dev *indio_dev = pf->indio_dev;
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struct tlc4541_state *st = iio_priv(indio_dev);
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int ret;
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ret = spi_sync(st->spi, &st->scan_single_msg);
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if (ret < 0)
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goto done;
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iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf,
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iio_get_time_ns(indio_dev));
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done:
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iio_trigger_notify_done(indio_dev->trig);
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return IRQ_HANDLED;
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}
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static int tlc4541_get_range(struct tlc4541_state *st)
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{
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int vref;
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vref = regulator_get_voltage(st->reg);
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if (vref < 0)
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return vref;
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vref /= 1000;
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return vref;
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}
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static int tlc4541_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val,
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int *val2,
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long m)
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{
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int ret = 0;
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struct tlc4541_state *st = iio_priv(indio_dev);
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switch (m) {
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case IIO_CHAN_INFO_RAW:
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ret = iio_device_claim_direct_mode(indio_dev);
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if (ret)
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return ret;
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ret = spi_sync(st->spi, &st->scan_single_msg);
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iio_device_release_direct_mode(indio_dev);
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if (ret < 0)
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return ret;
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*val = be16_to_cpu(st->rx_buf[0]);
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*val = *val >> chan->scan_type.shift;
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*val &= GENMASK(chan->scan_type.realbits - 1, 0);
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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ret = tlc4541_get_range(st);
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if (ret < 0)
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return ret;
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*val = ret;
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*val2 = chan->scan_type.realbits;
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return IIO_VAL_FRACTIONAL_LOG2;
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}
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return -EINVAL;
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}
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static const struct iio_info tlc4541_info = {
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.read_raw = &tlc4541_read_raw,
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.driver_module = THIS_MODULE,
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};
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static int tlc4541_probe(struct spi_device *spi)
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{
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struct tlc4541_state *st;
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struct iio_dev *indio_dev;
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const struct tlc4541_chip_info *info;
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int ret;
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int8_t device_init = 0;
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indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
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if (indio_dev == NULL)
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return -ENOMEM;
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st = iio_priv(indio_dev);
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spi_set_drvdata(spi, indio_dev);
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st->spi = spi;
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info = &tlc4541_chip_info[spi_get_device_id(spi)->driver_data];
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indio_dev->name = spi_get_device_id(spi)->name;
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indio_dev->dev.parent = &spi->dev;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = info->channels;
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indio_dev->num_channels = info->num_channels;
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indio_dev->info = &tlc4541_info;
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/* perform reset */
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spi_write(spi, &device_init, 1);
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/* Setup default message */
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st->scan_single_xfer[0].rx_buf = &st->rx_buf[0];
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st->scan_single_xfer[0].len = 3;
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st->scan_single_xfer[1].delay_usecs = 3;
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st->scan_single_xfer[2].rx_buf = &st->rx_buf[0];
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st->scan_single_xfer[2].len = 2;
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spi_message_init_with_transfers(&st->scan_single_msg,
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st->scan_single_xfer, 3);
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st->reg = devm_regulator_get(&spi->dev, "vref");
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if (IS_ERR(st->reg))
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return PTR_ERR(st->reg);
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ret = regulator_enable(st->reg);
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if (ret)
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return ret;
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ret = iio_triggered_buffer_setup(indio_dev, NULL,
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&tlc4541_trigger_handler, NULL);
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if (ret)
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goto error_disable_reg;
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ret = iio_device_register(indio_dev);
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if (ret)
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goto error_cleanup_buffer;
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return 0;
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error_cleanup_buffer:
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iio_triggered_buffer_cleanup(indio_dev);
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error_disable_reg:
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regulator_disable(st->reg);
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return ret;
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}
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static int tlc4541_remove(struct spi_device *spi)
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{
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struct iio_dev *indio_dev = spi_get_drvdata(spi);
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struct tlc4541_state *st = iio_priv(indio_dev);
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iio_device_unregister(indio_dev);
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iio_triggered_buffer_cleanup(indio_dev);
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regulator_disable(st->reg);
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return 0;
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}
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#ifdef CONFIG_OF
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static const struct of_device_id tlc4541_dt_ids[] = {
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{ .compatible = "ti,tlc3541", },
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{ .compatible = "ti,tlc4541", },
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{}
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};
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MODULE_DEVICE_TABLE(of, tlc4541_dt_ids);
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#endif
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static const struct spi_device_id tlc4541_id[] = {
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{"tlc3541", TLC3541},
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{"tlc4541", TLC4541},
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{}
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};
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MODULE_DEVICE_TABLE(spi, tlc4541_id);
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static struct spi_driver tlc4541_driver = {
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.driver = {
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.name = "tlc4541",
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.of_match_table = of_match_ptr(tlc4541_dt_ids),
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},
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.probe = tlc4541_probe,
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.remove = tlc4541_remove,
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.id_table = tlc4541_id,
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};
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module_spi_driver(tlc4541_driver);
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MODULE_AUTHOR("Phil Reid <preid@electromag.com.au>");
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MODULE_DESCRIPTION("Texas Instruments TLC4541 ADC");
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MODULE_LICENSE("GPL v2");
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