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Date: Fri, 31 Dec 2021 13:19:58 +0000
From: Iain Hunter <drhunter95@...il.com>
To: unlisted-recipients:; (no To-header on input)
Cc: iain@...terembedded.co.uk, Iain Hunter <drhunter95@...il.com>,
Jonathan Cameron <jic23@...nel.org>,
Lars-Peter Clausen <lars@...afoo.de>,
Alexandru Ardelean <aardelean@...iqon.com>,
Randy Dunlap <rdunlap@...radead.org>,
Andy Shevchenko <andy.shevchenko@...il.com>,
Cai Huoqing <caihuoqing@...du.com>,
Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>,
Tomislav Denis <tomislav.denis@....com>,
Oleksij Rempel <linux@...pel-privat.de>,
Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>,
Fabio Estevam <festevam@...il.com>,
Biju Das <biju.das.jz@...renesas.com>,
linux-kernel@...r.kernel.org, linux-iio@...r.kernel.org
Subject: [PATCH v4 2/2] add TI ads1018 driver to iio
Signed-off-by: Iain Hunter <drhunter95@...il.com>
---
drivers/iio/adc/Kconfig | 12 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ti-ads1018.c | 840 +++++++++++++++++++++++++++++++++++
3 files changed, 853 insertions(+)
create mode 100644 drivers/iio/adc/ti-ads1018.c
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 8bf5b62a73f4..129194755c03 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -1131,6 +1131,18 @@ config TI_ADS1015
This driver can also be built as a module. If so, the module will be
called ti-ads1015.
+config TI_ADS1018
+ tristate "Texas Instruments ADS1018 ADC"
+ depends on SPI
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ help
+ If you say yes here you get support for Texas Instruments ADS1018
+ ADC chip.
+
+ To compile this driver as a module, choose M here: the
+ module will be called ti-ads1018.
+
config TI_ADS7950
tristate "Texas Instruments ADS7950 ADC driver"
depends on SPI && GPIOLIB
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index d3f53549720c..da462538ec17 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -101,6 +101,7 @@ obj-$(CONFIG_TI_ADC108S102) += ti-adc108s102.o
obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o
obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
+obj-$(CONFIG_TI_ADS1018) += ti-ads1018.o
obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o
obj-$(CONFIG_TI_ADS8344) += ti-ads8344.o
obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
diff --git a/drivers/iio/adc/ti-ads1018.c b/drivers/iio/adc/ti-ads1018.c
new file mode 100644
index 000000000000..b22cd0a4d0bb
--- /dev/null
+++ b/drivers/iio/adc/ti-ads1018.c
@@ -0,0 +1,840 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ADS1018 - Texas Instruments Analog-to-Digital Converter
+ *
+ * Copyright 2021 Iain Hunter <iain@...terembedded.co.uk>
+ *
+ * Based on ti-ads1015.c
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * IIO driver for 12 bit SPI ADC ADS1018 from TI
+ *
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/pm_runtime.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/bitfield.h>
+#include <asm/unaligned.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+#define ADS1018_DRV_NAME "ads1018"
+
+#define ADS1018_CHANNELS 8
+
+#define ADS1018_CFG_NOP_MASK GENMASK(2, 1)
+#define ADS1018_CFG_PULL_UP_MASK BIT(3)
+#define ADS1018_CFG_TS_MODE_MASK BIT(4)
+#define ADS1018_CFG_DR_MASK GENMASK(7, 5)
+#define ADS1018_CFG_MODE_MASK BIT(8)
+#define ADS1018_CFG_PGA_MASK GENMASK(11, 9)
+#define ADS1018_CFG_MUX_MASK GENMASK(14, 12)
+
+#define ADS1018_PGA_2_048V 1
+
+#define ADS1018_MODE_SINGLE_SHOT 1
+#define ADS1018_MODE_CONTINUOUS 0
+
+#define ADS1018_STATE_RATE_128 0
+#define ADS1018_STATE_RATE_250 1
+#define ADS1018_STATE_RATE_490 2
+#define ADS1018_STATE_RATE_920 3
+#define ADS1018_STATE_RATE_1600 4
+#define ADS1018_STATE_RATE_2400 5
+#define ADS1018_STATE_RATE_3300 6
+
+#define ADS1018_TS_MODE_ADC 0
+#define ADS1018_TS_MODE_TEMP 1
+
+#define ADS1018_PULLUP_DOUT_DISABLE 0
+#define ADS1018_PULLUP_DOUT_ENABLE 1
+
+#define ADS1018_NOP_UPDATE_CONFIG 1
+#define ADS1018_RESERVED 1
+
+#define ADS1018_CONFIGURE \
+ (FIELD_PREP(ADS1018_CFG_PGA_MASK, ADS1018_PGA_2_048V) | \
+ FIELD_PREP(ADS1018_CFG_MODE_MASK, ADS1018_MODE_CONTINUOUS) | \
+ FIELD_PREP(ADS1018_CFG_DR_MASK, ADS1018_STATE_RATE_2400) | \
+ FIELD_PREP(ADS1018_CFG_TS_MODE_MASK, ADS1018_TS_MODE_ADC) | \
+ FIELD_PREP(ADS1018_CFG_PULL_UP_MASK, ADS1018_PULLUP_DOUT_ENABLE) | \
+ FIELD_PREP(ADS1018_CFG_NOP_MASK, ADS1018_NOP_UPDATE_CONFIG)| \
+ ADS1018_RESERVED)
+
+#define ADS1018_SLEEP_DELAY_MS 2000
+#define ADS1018_DEFAULT_PGA 2
+#define ADS1018_DEFAULT_DATA_RATE 4
+#define ADS1018_DEFAULT_CHAN 0
+
+enum chip_ids {
+ ADS1018};
+
+enum ads1018_channels {
+ ADS1018_AIN0_AIN1 = 0,
+ ADS1018_AIN0_AIN3,
+ ADS1018_AIN1_AIN3,
+ ADS1018_AIN2_AIN3,
+ ADS1018_AIN0,
+ ADS1018_AIN1,
+ ADS1018_AIN2,
+ ADS1018_AIN3,
+ ADS1018_TIMESTAMP,
+};
+
+struct ti_ads1018_chip_info {
+ const struct iio_chan_spec *channels;
+ unsigned int num_channels;
+};
+
+#define NUM_DIFF_CHAN 2
+unsigned int ti_ads1018_diff_channels[NUM_DIFF_CHAN];
+
+static const unsigned int ads1018_data_rate[] = {
+ 128, 250, 490, 920, 1600, 2400, 3300
+};
+
+/*
+ * Translation from PGA bits to full-scale positive and negative input voltage
+ * range in mV
+ */
+static int ads1018_fullscale_range[] = {
+ 6144, 4096, 2048, 1024, 512, 256
+};
+
+#define ADS1018_V_CHAN(_chan, _addr) { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .address = _addr, \
+ .channel = _chan, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+ .info_mask_separate_available = \
+ BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+ .scan_index = _addr, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 12, \
+ .storagebits = 16, \
+ .shift = 4, \
+ .endianness = IIO_CPU, \
+ }, \
+ .datasheet_name = "AIN"#_chan, \
+}
+
+#define ADS1018_V_DIFF_CHAN(_chan, _chan2, _addr) { \
+ .type = IIO_VOLTAGE, \
+ .differential = 1, \
+ .indexed = 1, \
+ .address = _addr, \
+ .channel = _chan, \
+ .channel2 = _chan2, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+ .info_mask_separate_available = \
+ BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+ .scan_index = _addr, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 12, \
+ .storagebits = 16, \
+ .shift = 4, \
+ .endianness = IIO_CPU, \
+ }, \
+ .datasheet_name = "AIN"#_chan"-AIN"#_chan2, \
+}
+
+struct ads1018_channel_data {
+ bool enabled;
+ unsigned int pga;
+ unsigned int data_rate;
+};
+
+struct ti_ads1018_state {
+ struct spi_device *spi;
+ struct spi_transfer scan_single_xfer[1];
+ struct spi_message scan_single_msg;
+
+ struct iio_trigger *trig;
+ /*
+ * Protects ADC ops, e.g: concurrent sysfs/buffered
+ * data reads, configuration updates
+ */
+ struct mutex lock;
+ struct ads1018_channel_data channel_data[ADS1018_CHANNELS];
+ unsigned int current_config;
+ unsigned int settings;
+ const unsigned int *data_rate;
+ /*
+ * Set to true when the ADC is switched to the continuous-conversion
+ * mode and exits from a power-down state. This flag is used to avoid
+ * getting the stale result from the conversion register.
+ */
+ bool conv_invalid;
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ *
+ */
+ unsigned char spi_rx_buf[sizeof(u32)]
+ ____cacheline_aligned;
+ unsigned char spi_tx_buf[sizeof(u32)]
+ ____cacheline_aligned;
+};
+
+static const struct iio_chan_spec ti_ads1018_channels[] = {
+ ADS1018_V_DIFF_CHAN(0, 1, ADS1018_AIN0_AIN1),
+ ADS1018_V_DIFF_CHAN(0, 3, ADS1018_AIN0_AIN3),
+ ADS1018_V_DIFF_CHAN(1, 3, ADS1018_AIN1_AIN3),
+ ADS1018_V_DIFF_CHAN(2, 3, ADS1018_AIN2_AIN3),
+ ADS1018_V_CHAN(0, ADS1018_AIN0),
+ ADS1018_V_CHAN(1, ADS1018_AIN1),
+ ADS1018_V_CHAN(2, ADS1018_AIN2),
+ ADS1018_V_CHAN(3, ADS1018_AIN3),
+ IIO_CHAN_SOFT_TIMESTAMP(ADS1018_TIMESTAMP),
+};
+
+static const struct ti_ads1018_chip_info ti_ads1018_chip = {
+ .channels = ti_ads1018_channels,
+ .num_channels = ARRAY_SIZE(ti_ads1018_channels),
+};
+
+static int ti_ads1018_write_config_register(struct ti_ads1018_state *st, int value)
+{
+ int ret;
+
+ /* Write new value to the first 2 bytes of the 4 byte SPI transfer */
+ put_unaligned_be16(value, (void *)&st->spi_tx_buf[0]);
+ put_unaligned_be16(0x0000, (void *)&st->spi_tx_buf[2]);
+
+ ret = spi_sync(st->spi, &st->scan_single_msg);
+ if (ret)
+ return ret;
+
+ /* Update the state current config based on result of this write
+ * the updated config register value is in second 16 bit word
+ * which is third and fourth byte
+ */
+ st->current_config = get_unaligned_be16((void *)&st->spi_rx_buf[2]);
+
+ return 0;
+}
+
+static int __maybe_unused
+ads1018_set_power_state(struct ti_ads1018_state *st, bool on)
+{
+ int ret;
+ struct spi_device *spi = st->spi;
+ struct device *dev = &(spi->dev);
+
+ if (pm_runtime_enabled(dev)) {
+ if (on) {
+ ret = pm_runtime_resume_and_get(dev);
+ } else {
+ pm_runtime_mark_last_busy(dev);
+ ret = pm_runtime_put_autosuspend(dev);
+ }
+
+ return ret < 0 ? ret : 0;
+ } else {
+ return 0;
+ }
+}
+
+static
+int ads1018_get_adc_result(struct ti_ads1018_state *st, int chan, int *val)
+{
+ int ret, pga, dr, dr_old, conv_time;
+ unsigned int old, mask, cfg;
+ unsigned int cmd;
+
+ if (chan < 0 || chan >= ADS1018_CHANNELS)
+ return -EINVAL;
+
+ old = st->current_config;
+ pga = st->channel_data[chan].pga;
+ dr = st->channel_data[chan].data_rate;
+ mask = ADS1018_CFG_MUX_MASK | ADS1018_CFG_PGA_MASK |
+ ADS1018_CFG_DR_MASK;
+ cfg = FIELD_PREP(ADS1018_CFG_MUX_MASK, chan) |
+ FIELD_PREP(ADS1018_CFG_PGA_MASK, pga) |
+ FIELD_PREP(ADS1018_CFG_DR_MASK, dr);
+
+ cfg = (old & ~mask) | (cfg & mask);
+ if (old != cfg) {
+ /* Update the configuration to the new one */
+ ret = ti_ads1018_write_config_register(st, cfg);
+ if (ret)
+ return ret;
+ st->conv_invalid = true;
+ }
+
+ if (st->conv_invalid) {
+ dr_old = FIELD_GET(ADS1018_CFG_DR_MASK, old);
+
+ conv_time = DIV_ROUND_UP(USEC_PER_SEC, st->data_rate[dr_old]);
+ conv_time += DIV_ROUND_UP(USEC_PER_SEC, st->data_rate[dr]);
+ conv_time += conv_time / 10; /* 10% internal clock inaccuracy */
+ usleep_range(conv_time, conv_time + 1);
+ st->conv_invalid = false;
+ }
+
+ /* For just a data read cmd is 0x0000 */
+ cmd = 0x0000;
+ put_unaligned_be16(cmd, (void *)&st->spi_tx_buf[0]);
+ put_unaligned_be16(0x0000, (void *)&st->spi_tx_buf[2]);
+
+ ret = spi_sync(st->spi, &st->scan_single_msg);
+ if (ret)
+ return ret;
+
+ *val = get_unaligned_be16((void *)&st->spi_rx_buf[0]);
+ return 0;
+}
+
+static irqreturn_t ti_ads1018_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct ti_ads1018_state *st = iio_priv(indio_dev);
+ /* Ensure natural alignment of timestamp */
+ struct {
+ s16 chan;
+ s64 timestamp __aligned(8);
+
+ } scan;
+
+ int chan, ret, res;
+
+ memset(&scan, 0, sizeof(scan));
+
+ mutex_lock(&st->lock);
+ chan = find_first_bit(indio_dev->active_scan_mask,
+ indio_dev->masklength);
+ ret = ads1018_get_adc_result(st, chan, &res);
+ if (ret < 0) {
+ mutex_unlock(&st->lock);
+ goto err;
+ }
+
+ scan.chan = res;
+ mutex_unlock(&st->lock);
+
+ iio_push_to_buffers_with_timestamp(indio_dev, &scan,
+ iio_get_time_ns(indio_dev));
+
+err:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static int ads1018_set_scale(struct ti_ads1018_state *st,
+ struct iio_chan_spec const *chan,
+ int scale, int uscale)
+{
+ int fullscale = div_s64((scale * 1000000LL + uscale) <<
+ (chan->scan_type.realbits - 1), 1000000);
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(ads1018_fullscale_range); i++) {
+ if (ads1018_fullscale_range[i] == fullscale) {
+ st->channel_data[chan->address].pga = i;
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static int ads1018_set_data_rate(struct ti_ads1018_state *st, int chan, int rate)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(ads1018_data_rate); i++) {
+ if (st->data_rate[i] == rate) {
+ st->channel_data[chan].data_rate = i;
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static int ads1018_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct ti_ads1018_state *st = iio_priv(indio_dev);
+ int ret, idx;
+
+ mutex_lock(&st->lock);
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW: {
+ int shift = chan->scan_type.shift;
+ int sign_bit = chan->scan_type.realbits - 1;
+
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ break;
+
+ ret = ads1018_set_power_state(st, true);
+ if (ret < 0)
+ goto release_direct;
+
+ ret = ads1018_get_adc_result(st, chan->address, val);
+ if (ret < 0) {
+ ads1018_set_power_state(st, false);
+ goto release_direct;
+ }
+
+ *val = sign_extend32(*val >> shift, sign_bit);
+
+ ret = ads1018_set_power_state(st, false);
+ if (ret < 0)
+ goto release_direct;
+
+ ret = IIO_VAL_INT;
+release_direct:
+ iio_device_release_direct_mode(indio_dev);
+ break;
+ }
+ case IIO_CHAN_INFO_SCALE:
+ idx = st->channel_data[chan->address].pga;
+ *val = ads1018_fullscale_range[idx];
+ *val2 = chan->scan_type.realbits - 1;
+ ret = IIO_VAL_FRACTIONAL_LOG2;
+ break;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ idx = st->channel_data[chan->address].data_rate;
+ *val = st->data_rate[idx];
+ ret = IIO_VAL_INT;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ mutex_unlock(&st->lock);
+
+ return ret;
+}
+
+static int ads1018_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long mask)
+{
+ struct ti_ads1018_state *st = iio_priv(indio_dev);
+ int idx;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ idx = st->channel_data[chan->address].pga;
+ *length = sizeof(int) / sizeof(int);
+ *vals = &(ads1018_fullscale_range[idx]);
+ *type = IIO_VAL_INT;
+ return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ idx = st->channel_data[chan->address].data_rate;
+ *length = sizeof(int) / sizeof(int);
+ *vals = &(st->data_rate[idx]);
+ *type = IIO_VAL_INT;
+ return IIO_AVAIL_LIST;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ads1018_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long mask)
+{
+ struct ti_ads1018_state *st = iio_priv(indio_dev);
+ int ret;
+
+ mutex_lock(&st->lock);
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ ret = ads1018_set_scale(st, chan, val, val2);
+ break;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ ret = ads1018_set_data_rate(st, chan->address, val);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ mutex_unlock(&st->lock);
+
+ return ret;
+}
+
+static int ads1018_buffer_preenable(struct iio_dev *indio_dev)
+{
+ return ads1018_set_power_state(iio_priv(indio_dev), true);
+}
+
+static int ads1018_buffer_postdisable(struct iio_dev *indio_dev)
+{
+ return ads1018_set_power_state(iio_priv(indio_dev), false);
+}
+
+static const struct iio_buffer_setup_ops ti_ads1018_buffer_setup_ops = {
+ .preenable = ads1018_buffer_preenable,
+ .postdisable = ads1018_buffer_postdisable,
+ .validate_scan_mask = &iio_validate_scan_mask_onehot,
+};
+
+static IIO_CONST_ATTR_NAMED(ads1018_scale_available, scale_available,
+ "3 2 1 0.5 0.25 0.125");
+
+static IIO_CONST_ATTR_NAMED(ads1018_sampling_frequency_available,
+ sampling_frequency_available, "128 250 490 920 1600 2400 3300");
+
+static struct attribute *ads1018_attributes[] = {
+ &iio_const_attr_ads1018_scale_available.dev_attr.attr,
+ &iio_const_attr_ads1018_sampling_frequency_available.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group ads1018_attribute_group = {
+ .attrs = ads1018_attributes,
+};
+
+
+static const struct iio_info ti_ads1018_info = {
+ .read_raw = ads1018_read_raw,
+ .read_avail = ads1018_read_avail,
+ .write_raw = ads1018_write_raw,
+ .attrs = &ads1018_attribute_group,
+};
+
+static int ads1018_validate_diff_channels(
+ struct device *dev, struct fwnode_handle *node,
+ unsigned int *diff_channels, unsigned int *channel)
+{
+ switch (diff_channels[0]) {
+
+ case 0:{
+ if (diff_channels[1] == 1)
+ *channel = ADS1018_AIN0_AIN1;
+ else if (diff_channels[1] == 3)
+ *channel = ADS1018_AIN0_AIN3;
+ else {
+ dev_err(dev, "invalid diff channel <%u %u> on %pfw\n",
+ diff_channels[0], diff_channels[1],
+ node);
+ fwnode_handle_put(node);
+ return -EINVAL;
+ }
+ break;
+ }
+ case 1:{
+ if (diff_channels[1] == 3)
+ *channel = ADS1018_AIN1_AIN3;
+ else {
+ dev_err(dev, "invalid diff channel <%u %u> on %pfw\n",
+ diff_channels[0], diff_channels[1],
+ node);
+ fwnode_handle_put(node);
+ return -EINVAL;
+ }
+ break;
+ }
+ case 2:{
+ if (diff_channels[1] == 3)
+ *channel = ADS1018_AIN2_AIN3;
+ else {
+ dev_err(dev, "invalid diff channel <%u %u> on %pfw\n",
+ diff_channels[0], diff_channels[1],
+ node);
+ fwnode_handle_put(node);
+ return -EINVAL;
+ }
+ break;
+ }
+ }
+ return 0;
+}
+
+
+static int ads1018_device_get_channels_config(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct ti_ads1018_state *data = iio_priv(indio_dev);
+ struct device *dev = &spi->dev;
+ struct fwnode_handle *node;
+ int i = -1;
+
+ if (!spi->dev.of_node ||
+ !of_get_next_child(spi->dev.of_node, NULL))
+ return -EINVAL;
+
+ device_for_each_child_node(dev, node) {
+ u32 pval;
+ unsigned int channel;
+ size_t number_diff_channels;
+
+ if (!fwnode_property_read_u32(node, "ti,adc-channels", &pval)) {
+ channel = pval+ADS1018_AIN0;
+ if (channel > ADS1018_AIN3) {
+ dev_err(dev,
+ "invalid single ended channel %u on %pfw\n",
+ channel, node);
+ fwnode_handle_put(node);
+ return -EINVAL;
+ }
+ }
+
+ number_diff_channels = fwnode_property_read_u32_array(node,
+ "ti,adc-diff-channels", NULL,
+ NUM_DIFF_CHAN);
+
+ if ((number_diff_channels == NUM_DIFF_CHAN) &&
+ (!fwnode_property_read_u32_array(node,
+ "ti,adc-diff-channels",
+ ti_ads1018_diff_channels,
+ NUM_DIFF_CHAN))) {
+
+ if (!ads1018_validate_diff_channels(dev, node,
+ ti_ads1018_diff_channels,
+ &channel))
+ return -EINVAL;
+ }
+
+ data->channel_data[channel].enabled = 1;
+ data->channel_data[channel].pga = ADS1018_DEFAULT_PGA;
+ data->channel_data[channel].data_rate = ADS1018_DEFAULT_DATA_RATE;
+
+ i++;
+ }
+
+ return i < 0 ? -EINVAL : 0;
+}
+
+static void ads1018_get_channels_config(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct ti_ads1018_state *data = iio_priv(indio_dev);
+ unsigned int k;
+
+ if (!ads1018_device_get_channels_config(spi))
+ return;
+ /* fallback on default configuration */
+ for (k = 0; k < ADS1018_CHANNELS; ++k) {
+ data->channel_data[k].enabled = 0;
+ data->channel_data[k].pga = ADS1018_DEFAULT_PGA;
+ data->channel_data[k].data_rate = ADS1018_DEFAULT_DATA_RATE;
+ }
+}
+
+static int ads1018_set_conv_mode(struct ti_ads1018_state *st, int mode)
+{
+ int updatedConfig;
+
+ updatedConfig = st->current_config & ~(ADS1018_CFG_MODE_MASK);
+ updatedConfig |= FIELD_PREP(ADS1018_CFG_MODE_MASK, mode);
+
+ return ti_ads1018_write_config_register(st, updatedConfig);
+}
+
+static int ti_ads1018_set_trigger_state(struct iio_trigger *trig, bool enable)
+{
+ return 0;
+}
+
+static const struct iio_trigger_ops ti_ads1018_trigger_ops = {
+ .set_trigger_state = ti_ads1018_set_trigger_state,
+ .validate_device = iio_trigger_validate_own_device,
+};
+
+static void ads1018_disable(void *data)
+{
+ struct ti_ads1018_state *st = (struct ti_ads1018_state *) data;
+ struct spi_device *spi = st->spi;
+
+ pm_runtime_disable(&spi->dev);
+ pm_runtime_set_suspended(&spi->dev);
+ pm_runtime_put_noidle(&spi->dev);
+
+ /* power down single shot mode */
+ ads1018_set_conv_mode(st, ADS1018_MODE_SINGLE_SHOT);
+}
+
+static int ti_ads1018_probe(struct spi_device *spi)
+{
+ const struct ti_ads1018_chip_info *info;
+ struct ti_ads1018_state *st;
+ struct iio_dev *indio_dev;
+ int ret;
+ int i;
+ int config;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+
+ st->spi = spi;
+ config = ADS1018_CONFIGURE;
+ spi_set_drvdata(spi, indio_dev);
+
+ mutex_init(&st->lock);
+
+ info = &ti_ads1018_chip;
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = info->channels;
+ indio_dev->num_channels = info->num_channels;
+ indio_dev->info = &ti_ads1018_info;
+ st->data_rate = &ads1018_data_rate[0];
+
+ ret = devm_add_action_or_reset(&spi->dev, ads1018_disable,
+ st);
+
+ if (ret)
+ return ret;
+
+ /* allocate and then register trigger with IIO core */
+ st->trig = devm_iio_trigger_alloc(indio_dev->dev.parent, "%s-dev%d",
+ indio_dev->name,
+ iio_device_id(indio_dev));
+ if (st->trig == NULL)
+ return -ENOMEM;
+
+ st->trig->ops = &ti_ads1018_trigger_ops;
+
+ devm_iio_trigger_register(indio_dev->dev.parent, st->trig);
+
+ /* set the default trigger */
+ indio_dev->trig = iio_trigger_get(st->trig);
+
+ ads1018_get_channels_config(spi);
+
+ /* Find out if DT has enabled any of the channels, only one allowed so
+ * just take the first one
+ */
+ for (i = 0; i < info->num_channels; i++)
+ if (st->channel_data[i].enabled == 1)
+ break;
+
+ /* If a channel was enabled set it by default in the device */
+ if (i < info->num_channels) {
+ /* mask out the mux bits */
+ config &= ~(ADS1018_CFG_MUX_MASK);
+ config |= FIELD_PREP(ADS1018_CFG_MUX_MASK, i);
+ }
+
+ /*
+ * Always use 4 * 8 bit transfer mode so that the status is read back
+ * in the second 16 bit word. This allows us to track when updated
+ * configuration needs to be applied.
+ */
+ st->scan_single_xfer[0].tx_buf = &st->spi_tx_buf[0];
+ st->scan_single_xfer[0].rx_buf = &st->spi_rx_buf[0];
+ st->scan_single_xfer[0].len = 4;
+ st->scan_single_xfer[0].cs_change = 0;
+ st->scan_single_xfer[0].bits_per_word = 8;
+
+ spi_message_init_with_transfers(&st->scan_single_msg,
+ st->scan_single_xfer, 1);
+
+ ret = ti_ads1018_write_config_register(st, config);
+ if (ret < 0) {
+ dev_err(&spi->dev, "ads1018 configuration failed\n");
+ return ret;
+ }
+
+ ret = devm_iio_triggered_buffer_setup(indio_dev->dev.parent,
+ indio_dev, NULL,
+ ti_ads1018_trigger_handler,
+ &ti_ads1018_buffer_setup_ops);
+ if (ret < 0) {
+ dev_err(&spi->dev, "iio triggered buffer setup failed\n");
+ return ret;
+ }
+
+ ret = ads1018_set_conv_mode(st, ADS1018_MODE_CONTINUOUS);
+ if (ret)
+ return ret;
+
+ st->conv_invalid = true;
+
+ ret = pm_runtime_set_active(&spi->dev);
+ if (ret)
+ return ret;
+ pm_runtime_set_autosuspend_delay(&spi->dev, ADS1018_SLEEP_DELAY_MS);
+ pm_runtime_use_autosuspend(&spi->dev);
+ pm_runtime_enable(&spi->dev);
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+#ifdef CONFIG_PM
+static int ads1018_runtime_suspend(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ti_ads1018_state *st = iio_priv(indio_dev);
+
+ return ads1018_set_conv_mode(st, ADS1018_MODE_SINGLE_SHOT);
+}
+
+static int ads1018_runtime_resume(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ti_ads1018_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = ads1018_set_conv_mode(st, ADS1018_MODE_CONTINUOUS);
+ if (!ret)
+ st->conv_invalid = true;
+
+ return ret;
+}
+#endif
+
+static const struct dev_pm_ops ads1018_pm_ops = {
+ SET_RUNTIME_PM_OPS(ads1018_runtime_suspend,
+ ads1018_runtime_resume, NULL)
+};
+
+static const struct spi_device_id ti_ads1018_id[] = {
+ { "ads1018", ADS1018 },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, ti_ads1018_id);
+
+static const struct of_device_id ads1018_of_table[] = {
+ { .compatible = "ti,ads1018", .data = &ti_ads1018_chip },
+ { },
+};
+MODULE_DEVICE_TABLE(of, ads1018_of_table);
+
+static struct spi_driver ti_ads1018_driver = {
+ .driver = {
+ .name = ADS1018_DRV_NAME,
+ .of_match_table = ads1018_of_table,
+ .pm = &ads1018_pm_ops,
+ },
+ .probe = ti_ads1018_probe,
+ .id_table = ti_ads1018_id,
+};
+module_spi_driver(ti_ads1018_driver);
+
+MODULE_AUTHOR("Iain Hunter <iain@...terembedded.co.uk>");
+MODULE_DESCRIPTION("TI TI_ADS1018 ADC");
+MODULE_LICENSE("GPL v2");
--
2.25.1
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