From 2985a5d88455a3edd51358fc77f61b684d0e9265 Mon Sep 17 00:00:00 2001 From: Stefan Popa Date: Mon, 17 Dec 2018 14:23:39 +0200 Subject: staging: iio: adc: ad7606: Move out of staging Move ad7606 ADC driver out of staging and into the mainline. Signed-off-by: Stefan Popa Signed-off-by: Jonathan Cameron --- drivers/iio/adc/ad7606.c | 583 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 583 insertions(+) create mode 100644 drivers/iio/adc/ad7606.c (limited to 'drivers/iio/adc/ad7606.c') diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c new file mode 100644 index 000000000000..ebb8de03bbce --- /dev/null +++ b/drivers/iio/adc/ad7606.c @@ -0,0 +1,583 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * AD7606 SPI ADC driver + * + * Copyright 2011 Analog Devices Inc. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +#include "ad7606.h" + +/* + * Scales are computed as 5000/32768 and 10000/32768 respectively, + * so that when applied to the raw values they provide mV values + */ +static const unsigned int scale_avail[2] = { + 152588, 305176 +}; + +static const unsigned int ad7606_oversampling_avail[7] = { + 1, 2, 4, 8, 16, 32, 64, +}; + +static int ad7606_reset(struct ad7606_state *st) +{ + if (st->gpio_reset) { + gpiod_set_value(st->gpio_reset, 1); + ndelay(100); /* t_reset >= 100ns */ + gpiod_set_value(st->gpio_reset, 0); + return 0; + } + + return -ENODEV; +} + +static int ad7606_read_samples(struct ad7606_state *st) +{ + unsigned int num = st->chip_info->num_channels; + u16 *data = st->data; + int ret; + + /* + * The frstdata signal is set to high while and after reading the sample + * of the first channel and low for all other channels. This can be used + * to check that the incoming data is correctly aligned. During normal + * operation the data should never become unaligned, but some glitch or + * electrostatic discharge might cause an extra read or clock cycle. + * Monitoring the frstdata signal allows to recover from such failure + * situations. + */ + + if (st->gpio_frstdata) { + ret = st->bops->read_block(st->dev, 1, data); + if (ret) + return ret; + + if (!gpiod_get_value(st->gpio_frstdata)) { + ad7606_reset(st); + return -EIO; + } + + data++; + num--; + } + + return st->bops->read_block(st->dev, num, data); +} + +static irqreturn_t ad7606_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct ad7606_state *st = iio_priv(indio_dev); + int ret; + + mutex_lock(&st->lock); + + ret = ad7606_read_samples(st); + if (ret == 0) + iio_push_to_buffers_with_timestamp(indio_dev, st->data, + iio_get_time_ns(indio_dev)); + + iio_trigger_notify_done(indio_dev->trig); + /* The rising edge of the CONVST signal starts a new conversion. */ + gpiod_set_value(st->gpio_convst, 1); + + mutex_unlock(&st->lock); + + return IRQ_HANDLED; +} + +static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch) +{ + struct ad7606_state *st = iio_priv(indio_dev); + int ret; + + gpiod_set_value(st->gpio_convst, 1); + ret = wait_for_completion_timeout(&st->completion, + msecs_to_jiffies(1000)); + if (!ret) { + ret = -ETIMEDOUT; + goto error_ret; + } + + ret = ad7606_read_samples(st); + if (ret == 0) + ret = st->data[ch]; + +error_ret: + gpiod_set_value(st->gpio_convst, 0); + + return ret; +} + +static int ad7606_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, + int *val2, + long m) +{ + int ret; + struct ad7606_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 = ad7606_scan_direct(indio_dev, chan->address); + iio_device_release_direct_mode(indio_dev); + + if (ret < 0) + return ret; + *val = (short)ret; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + *val = 0; + *val2 = scale_avail[st->range]; + return IIO_VAL_INT_PLUS_MICRO; + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + *val = st->oversampling; + return IIO_VAL_INT; + } + return -EINVAL; +} + +static ssize_t in_voltage_scale_available_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int i, len = 0; + + for (i = 0; i < ARRAY_SIZE(scale_avail); i++) + len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06u ", + scale_avail[i]); + + buf[len - 1] = '\n'; + + return len; +} + +static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0); + +static int ad7606_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, + int val2, + long mask) +{ + struct ad7606_state *st = iio_priv(indio_dev); + DECLARE_BITMAP(values, 3); + int i; + + switch (mask) { + case IIO_CHAN_INFO_SCALE: + mutex_lock(&st->lock); + i = find_closest(val2, scale_avail, ARRAY_SIZE(scale_avail)); + gpiod_set_value(st->gpio_range, i); + st->range = i; + mutex_unlock(&st->lock); + + return 0; + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + if (val2) + return -EINVAL; + i = find_closest(val, ad7606_oversampling_avail, + ARRAY_SIZE(ad7606_oversampling_avail)); + + values[0] = i; + + mutex_lock(&st->lock); + gpiod_set_array_value(ARRAY_SIZE(values), st->gpio_os->desc, + st->gpio_os->info, values); + st->oversampling = ad7606_oversampling_avail[i]; + mutex_unlock(&st->lock); + + return 0; + default: + return -EINVAL; + } +} + +static IIO_CONST_ATTR(oversampling_ratio_available, "1 2 4 8 16 32 64"); + +static struct attribute *ad7606_attributes_os_and_range[] = { + &iio_dev_attr_in_voltage_scale_available.dev_attr.attr, + &iio_const_attr_oversampling_ratio_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group ad7606_attribute_group_os_and_range = { + .attrs = ad7606_attributes_os_and_range, +}; + +static struct attribute *ad7606_attributes_os[] = { + &iio_const_attr_oversampling_ratio_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group ad7606_attribute_group_os = { + .attrs = ad7606_attributes_os, +}; + +static struct attribute *ad7606_attributes_range[] = { + &iio_dev_attr_in_voltage_scale_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group ad7606_attribute_group_range = { + .attrs = ad7606_attributes_range, +}; + +#define AD760X_CHANNEL(num, mask) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = num, \ + .address = num, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\ + .info_mask_shared_by_all = mask, \ + .scan_index = num, \ + .scan_type = { \ + .sign = 's', \ + .realbits = 16, \ + .storagebits = 16, \ + .endianness = IIO_CPU, \ + }, \ +} + +#define AD7605_CHANNEL(num) \ + AD760X_CHANNEL(num, 0) + +#define AD7606_CHANNEL(num) \ + AD760X_CHANNEL(num, BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO)) + +static const struct iio_chan_spec ad7605_channels[] = { + IIO_CHAN_SOFT_TIMESTAMP(4), + AD7605_CHANNEL(0), + AD7605_CHANNEL(1), + AD7605_CHANNEL(2), + AD7605_CHANNEL(3), +}; + +static const struct iio_chan_spec ad7606_channels[] = { + IIO_CHAN_SOFT_TIMESTAMP(8), + AD7606_CHANNEL(0), + AD7606_CHANNEL(1), + AD7606_CHANNEL(2), + AD7606_CHANNEL(3), + AD7606_CHANNEL(4), + AD7606_CHANNEL(5), + AD7606_CHANNEL(6), + AD7606_CHANNEL(7), +}; + +static const struct ad7606_chip_info ad7606_chip_info_tbl[] = { + /* More devices added in future */ + [ID_AD7605_4] = { + .channels = ad7605_channels, + .num_channels = 5, + }, + [ID_AD7606_8] = { + .channels = ad7606_channels, + .num_channels = 9, + .has_oversampling = true, + }, + [ID_AD7606_6] = { + .channels = ad7606_channels, + .num_channels = 7, + .has_oversampling = true, + }, + [ID_AD7606_4] = { + .channels = ad7606_channels, + .num_channels = 5, + .has_oversampling = true, + }, +}; + +static int ad7606_request_gpios(struct ad7606_state *st) +{ + struct device *dev = st->dev; + + st->gpio_convst = devm_gpiod_get(dev, "adi,conversion-start", + GPIOD_OUT_LOW); + if (IS_ERR(st->gpio_convst)) + return PTR_ERR(st->gpio_convst); + + st->gpio_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); + if (IS_ERR(st->gpio_reset)) + return PTR_ERR(st->gpio_reset); + + st->gpio_range = devm_gpiod_get_optional(dev, "adi,range", + GPIOD_OUT_LOW); + if (IS_ERR(st->gpio_range)) + return PTR_ERR(st->gpio_range); + + st->gpio_standby = devm_gpiod_get_optional(dev, "standby", + GPIOD_OUT_HIGH); + if (IS_ERR(st->gpio_standby)) + return PTR_ERR(st->gpio_standby); + + st->gpio_frstdata = devm_gpiod_get_optional(dev, "adi,first-data", + GPIOD_IN); + if (IS_ERR(st->gpio_frstdata)) + return PTR_ERR(st->gpio_frstdata); + + if (!st->chip_info->has_oversampling) + return 0; + + st->gpio_os = devm_gpiod_get_array_optional(dev, + "adi,oversampling-ratio", + GPIOD_OUT_LOW); + return PTR_ERR_OR_ZERO(st->gpio_os); +} + +/* + * The BUSY signal indicates when conversions are in progress, so when a rising + * edge of CONVST is applied, BUSY goes logic high and transitions low at the + * end of the entire conversion process. The falling edge of the BUSY signal + * triggers this interrupt. + */ +static irqreturn_t ad7606_interrupt(int irq, void *dev_id) +{ + struct iio_dev *indio_dev = dev_id; + struct ad7606_state *st = iio_priv(indio_dev); + + if (iio_buffer_enabled(indio_dev)) { + gpiod_set_value(st->gpio_convst, 0); + iio_trigger_poll_chained(st->trig); + } else { + complete(&st->completion); + } + + return IRQ_HANDLED; +}; + +static int ad7606_validate_trigger(struct iio_dev *indio_dev, + struct iio_trigger *trig) +{ + struct ad7606_state *st = iio_priv(indio_dev); + + if (st->trig != trig) + return -EINVAL; + + return 0; +} + +static int ad7606_buffer_postenable(struct iio_dev *indio_dev) +{ + struct ad7606_state *st = iio_priv(indio_dev); + + iio_triggered_buffer_postenable(indio_dev); + gpiod_set_value(st->gpio_convst, 1); + + return 0; +} + +static int ad7606_buffer_predisable(struct iio_dev *indio_dev) +{ + struct ad7606_state *st = iio_priv(indio_dev); + + gpiod_set_value(st->gpio_convst, 0); + + return iio_triggered_buffer_predisable(indio_dev); +} + +static const struct iio_buffer_setup_ops ad7606_buffer_ops = { + .postenable = &ad7606_buffer_postenable, + .predisable = &ad7606_buffer_predisable, +}; + +static const struct iio_info ad7606_info_no_os_or_range = { + .read_raw = &ad7606_read_raw, + .validate_trigger = &ad7606_validate_trigger, +}; + +static const struct iio_info ad7606_info_os_and_range = { + .read_raw = &ad7606_read_raw, + .write_raw = &ad7606_write_raw, + .attrs = &ad7606_attribute_group_os_and_range, + .validate_trigger = &ad7606_validate_trigger, +}; + +static const struct iio_info ad7606_info_os = { + .read_raw = &ad7606_read_raw, + .write_raw = &ad7606_write_raw, + .attrs = &ad7606_attribute_group_os, + .validate_trigger = &ad7606_validate_trigger, +}; + +static const struct iio_info ad7606_info_range = { + .read_raw = &ad7606_read_raw, + .write_raw = &ad7606_write_raw, + .attrs = &ad7606_attribute_group_range, + .validate_trigger = &ad7606_validate_trigger, +}; + +static const struct iio_trigger_ops ad7606_trigger_ops = { + .validate_device = iio_trigger_validate_own_device, +}; + +static void ad7606_regulator_disable(void *data) +{ + struct ad7606_state *st = data; + + regulator_disable(st->reg); +} + +int ad7606_probe(struct device *dev, int irq, void __iomem *base_address, + const char *name, unsigned int id, + const struct ad7606_bus_ops *bops) +{ + struct ad7606_state *st; + int ret; + struct iio_dev *indio_dev; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + + st = iio_priv(indio_dev); + dev_set_drvdata(dev, indio_dev); + + st->dev = dev; + mutex_init(&st->lock); + st->bops = bops; + st->base_address = base_address; + /* tied to logic low, analog input range is +/- 5V */ + st->range = 0; + st->oversampling = 1; + + st->reg = devm_regulator_get(dev, "avcc"); + if (IS_ERR(st->reg)) + return PTR_ERR(st->reg); + + ret = regulator_enable(st->reg); + if (ret) { + dev_err(dev, "Failed to enable specified AVcc supply\n"); + return ret; + } + + ret = devm_add_action_or_reset(dev, ad7606_regulator_disable, st); + if (ret) + return ret; + + st->chip_info = &ad7606_chip_info_tbl[id]; + + ret = ad7606_request_gpios(st); + if (ret) + return ret; + + indio_dev->dev.parent = dev; + if (st->gpio_os) { + if (st->gpio_range) + indio_dev->info = &ad7606_info_os_and_range; + else + indio_dev->info = &ad7606_info_os; + } else { + if (st->gpio_range) + indio_dev->info = &ad7606_info_range; + else + indio_dev->info = &ad7606_info_no_os_or_range; + } + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->name = name; + indio_dev->channels = st->chip_info->channels; + indio_dev->num_channels = st->chip_info->num_channels; + + init_completion(&st->completion); + + ret = ad7606_reset(st); + if (ret) + dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n"); + + st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", + indio_dev->name, indio_dev->id); + if (!st->trig) + return -ENOMEM; + + st->trig->ops = &ad7606_trigger_ops; + st->trig->dev.parent = dev; + iio_trigger_set_drvdata(st->trig, indio_dev); + ret = devm_iio_trigger_register(dev, st->trig); + if (ret) + return ret; + + indio_dev->trig = iio_trigger_get(st->trig); + + ret = devm_request_threaded_irq(dev, irq, + NULL, + &ad7606_interrupt, + IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + name, indio_dev); + if (ret) + return ret; + + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, + &iio_pollfunc_store_time, + &ad7606_trigger_handler, + &ad7606_buffer_ops); + if (ret) + return ret; + + return devm_iio_device_register(dev, indio_dev); +} +EXPORT_SYMBOL_GPL(ad7606_probe); + +#ifdef CONFIG_PM_SLEEP + +static int ad7606_suspend(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct ad7606_state *st = iio_priv(indio_dev); + + if (st->gpio_standby) { + gpiod_set_value(st->gpio_range, 1); + gpiod_set_value(st->gpio_standby, 0); + } + + return 0; +} + +static int ad7606_resume(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct ad7606_state *st = iio_priv(indio_dev); + + if (st->gpio_standby) { + gpiod_set_value(st->gpio_range, st->range); + gpiod_set_value(st->gpio_standby, 1); + ad7606_reset(st); + } + + return 0; +} + +SIMPLE_DEV_PM_OPS(ad7606_pm_ops, ad7606_suspend, ad7606_resume); +EXPORT_SYMBOL_GPL(ad7606_pm_ops); + +#endif + +MODULE_AUTHOR("Michael Hennerich "); +MODULE_DESCRIPTION("Analog Devices AD7606 ADC"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3