diff options
Diffstat (limited to 'drivers/iio/cdc/ad7150.c')
-rw-r--r-- | drivers/iio/cdc/ad7150.c | 673 |
1 files changed, 673 insertions, 0 deletions
diff --git a/drivers/iio/cdc/ad7150.c b/drivers/iio/cdc/ad7150.c new file mode 100644 index 000000000..ebe112b46 --- /dev/null +++ b/drivers/iio/cdc/ad7150.c @@ -0,0 +1,673 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * AD7150 capacitive sensor driver supporting AD7150/1/6 + * + * Copyright 2010-2011 Analog Devices Inc. + * Copyright 2021 Jonathan Cameron <Jonathan.Cameron@huawei.com> + */ + +#include <linux/bitfield.h> +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/i2c.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/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/events.h> + +#define AD7150_STATUS_REG 0 +#define AD7150_STATUS_OUT1 BIT(3) +#define AD7150_STATUS_OUT2 BIT(5) +#define AD7150_CH1_DATA_HIGH_REG 1 +#define AD7150_CH2_DATA_HIGH_REG 3 +#define AD7150_CH1_AVG_HIGH_REG 5 +#define AD7150_CH2_AVG_HIGH_REG 7 +#define AD7150_CH1_SENSITIVITY_REG 9 +#define AD7150_CH1_THR_HOLD_H_REG 9 +#define AD7150_CH1_TIMEOUT_REG 10 +#define AD7150_CH_TIMEOUT_RECEDING GENMASK(3, 0) +#define AD7150_CH_TIMEOUT_APPROACHING GENMASK(7, 4) +#define AD7150_CH1_SETUP_REG 11 +#define AD7150_CH2_SENSITIVITY_REG 12 +#define AD7150_CH2_THR_HOLD_H_REG 12 +#define AD7150_CH2_TIMEOUT_REG 13 +#define AD7150_CH2_SETUP_REG 14 +#define AD7150_CFG_REG 15 +#define AD7150_CFG_FIX BIT(7) +#define AD7150_CFG_THRESHTYPE_MSK GENMASK(6, 5) +#define AD7150_CFG_TT_NEG 0x0 +#define AD7150_CFG_TT_POS 0x1 +#define AD7150_CFG_TT_IN_WINDOW 0x2 +#define AD7150_CFG_TT_OUT_WINDOW 0x3 +#define AD7150_PD_TIMER_REG 16 +#define AD7150_CH1_CAPDAC_REG 17 +#define AD7150_CH2_CAPDAC_REG 18 +#define AD7150_SN3_REG 19 +#define AD7150_SN2_REG 20 +#define AD7150_SN1_REG 21 +#define AD7150_SN0_REG 22 +#define AD7150_ID_REG 23 + +enum { + AD7150, + AD7151, +}; + +/** + * struct ad7150_chip_info - instance specific chip data + * @client: i2c client for this device + * @threshold: thresholds for simple capacitance value events + * @thresh_sensitivity: threshold for simple capacitance offset + * from 'average' value. + * @thresh_timeout: a timeout, in samples from the moment an + * adaptive threshold event occurs to when the average + * value jumps to current value. Note made up of two fields, + * 3:0 are for timeout receding - applies if below lower threshold + * 7:4 are for timeout approaching - applies if above upper threshold + * @state_lock: ensure consistent state of this structure wrt the + * hardware. + * @interrupts: one or two interrupt numbers depending on device type. + * @int_enabled: is a given interrupt currently enabled. + * @type: threshold type + * @dir: threshold direction + */ +struct ad7150_chip_info { + struct i2c_client *client; + u16 threshold[2][2]; + u8 thresh_sensitivity[2][2]; + u8 thresh_timeout[2][2]; + struct mutex state_lock; + int interrupts[2]; + bool int_enabled[2]; + enum iio_event_type type; + enum iio_event_direction dir; +}; + +static const u8 ad7150_addresses[][6] = { + { AD7150_CH1_DATA_HIGH_REG, AD7150_CH1_AVG_HIGH_REG, + AD7150_CH1_SETUP_REG, AD7150_CH1_THR_HOLD_H_REG, + AD7150_CH1_SENSITIVITY_REG, AD7150_CH1_TIMEOUT_REG }, + { AD7150_CH2_DATA_HIGH_REG, AD7150_CH2_AVG_HIGH_REG, + AD7150_CH2_SETUP_REG, AD7150_CH2_THR_HOLD_H_REG, + AD7150_CH2_SENSITIVITY_REG, AD7150_CH2_TIMEOUT_REG }, +}; + +static int ad7150_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, + int *val2, + long mask) +{ + struct ad7150_chip_info *chip = iio_priv(indio_dev); + int channel = chan->channel; + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = i2c_smbus_read_word_swapped(chip->client, + ad7150_addresses[channel][0]); + if (ret < 0) + return ret; + *val = ret >> 4; + + return IIO_VAL_INT; + case IIO_CHAN_INFO_AVERAGE_RAW: + ret = i2c_smbus_read_word_swapped(chip->client, + ad7150_addresses[channel][1]); + if (ret < 0) + return ret; + *val = ret; + + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + /* + * Base units for capacitance are nano farads and the value + * calculated from the datasheet formula is in picofarad + * so multiply by 1000 + */ + *val = 1000; + *val2 = 40944 >> 4; /* To match shift in _RAW */ + return IIO_VAL_FRACTIONAL; + case IIO_CHAN_INFO_OFFSET: + *val = -(12288 >> 4); /* To match shift in _RAW */ + return IIO_VAL_INT; + case IIO_CHAN_INFO_SAMP_FREQ: + /* Strangely same for both 1 and 2 chan parts */ + *val = 100; + return IIO_VAL_INT; + default: + return -EINVAL; + } +} + +static int ad7150_read_event_config(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir) +{ + struct ad7150_chip_info *chip = iio_priv(indio_dev); + u8 threshtype; + bool thrfixed; + int ret; + + ret = i2c_smbus_read_byte_data(chip->client, AD7150_CFG_REG); + if (ret < 0) + return ret; + + threshtype = FIELD_GET(AD7150_CFG_THRESHTYPE_MSK, ret); + + /*check if threshold mode is fixed or adaptive*/ + thrfixed = FIELD_GET(AD7150_CFG_FIX, ret); + + switch (type) { + case IIO_EV_TYPE_THRESH_ADAPTIVE: + if (dir == IIO_EV_DIR_RISING) + return !thrfixed && (threshtype == AD7150_CFG_TT_POS); + return !thrfixed && (threshtype == AD7150_CFG_TT_NEG); + case IIO_EV_TYPE_THRESH: + if (dir == IIO_EV_DIR_RISING) + return thrfixed && (threshtype == AD7150_CFG_TT_POS); + return thrfixed && (threshtype == AD7150_CFG_TT_NEG); + default: + break; + } + return -EINVAL; +} + +/* state_lock should be held to ensure consistent state */ +static int ad7150_write_event_params(struct iio_dev *indio_dev, + unsigned int chan, + enum iio_event_type type, + enum iio_event_direction dir) +{ + struct ad7150_chip_info *chip = iio_priv(indio_dev); + int rising = (dir == IIO_EV_DIR_RISING); + + /* Only update value live, if parameter is in use */ + if ((type != chip->type) || (dir != chip->dir)) + return 0; + + switch (type) { + /* Note completely different from the adaptive versions */ + case IIO_EV_TYPE_THRESH: { + u16 value = chip->threshold[rising][chan]; + return i2c_smbus_write_word_swapped(chip->client, + ad7150_addresses[chan][3], + value); + } + case IIO_EV_TYPE_THRESH_ADAPTIVE: { + int ret; + u8 sens, timeout; + + sens = chip->thresh_sensitivity[rising][chan]; + ret = i2c_smbus_write_byte_data(chip->client, + ad7150_addresses[chan][4], + sens); + if (ret) + return ret; + + /* + * Single timeout register contains timeouts for both + * directions. + */ + timeout = FIELD_PREP(AD7150_CH_TIMEOUT_APPROACHING, + chip->thresh_timeout[1][chan]); + timeout |= FIELD_PREP(AD7150_CH_TIMEOUT_RECEDING, + chip->thresh_timeout[0][chan]); + return i2c_smbus_write_byte_data(chip->client, + ad7150_addresses[chan][5], + timeout); + } + default: + return -EINVAL; + } +} + +static int ad7150_write_event_config(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, int state) +{ + struct ad7150_chip_info *chip = iio_priv(indio_dev); + int ret = 0; + + /* + * There is only a single shared control and no on chip + * interrupt disables for the two interrupt lines. + * So, enabling will switch the events configured to enable + * whatever was most recently requested and if necessary enable_irq() + * the interrupt and any disable will disable_irq() for that + * channels interrupt. + */ + if (!state) { + if ((chip->int_enabled[chan->channel]) && + (type == chip->type) && (dir == chip->dir)) { + disable_irq(chip->interrupts[chan->channel]); + chip->int_enabled[chan->channel] = false; + } + return 0; + } + + mutex_lock(&chip->state_lock); + if ((type != chip->type) || (dir != chip->dir)) { + int rising = (dir == IIO_EV_DIR_RISING); + u8 thresh_type, cfg, fixed; + + /* + * Need to temporarily disable both interrupts if + * enabled - this is to avoid races around changing + * config and thresholds. + * Note enable/disable_irq() are reference counted so + * no need to check if already enabled. + */ + disable_irq(chip->interrupts[0]); + disable_irq(chip->interrupts[1]); + + ret = i2c_smbus_read_byte_data(chip->client, AD7150_CFG_REG); + if (ret < 0) + goto error_ret; + + cfg = ret & ~(AD7150_CFG_THRESHTYPE_MSK | AD7150_CFG_FIX); + + if (type == IIO_EV_TYPE_THRESH_ADAPTIVE) + fixed = 0; + else + fixed = 1; + + if (rising) + thresh_type = AD7150_CFG_TT_POS; + else + thresh_type = AD7150_CFG_TT_NEG; + + cfg |= FIELD_PREP(AD7150_CFG_FIX, fixed) | + FIELD_PREP(AD7150_CFG_THRESHTYPE_MSK, thresh_type); + + ret = i2c_smbus_write_byte_data(chip->client, AD7150_CFG_REG, + cfg); + if (ret < 0) + goto error_ret; + + /* + * There is a potential race condition here, but not easy + * to close given we can't disable the interrupt at the + * chip side of things. Rely on the status bit. + */ + chip->type = type; + chip->dir = dir; + + /* update control attributes */ + ret = ad7150_write_event_params(indio_dev, chan->channel, type, + dir); + if (ret) + goto error_ret; + /* reenable any irq's we disabled whilst changing mode */ + enable_irq(chip->interrupts[0]); + enable_irq(chip->interrupts[1]); + } + if (!chip->int_enabled[chan->channel]) { + enable_irq(chip->interrupts[chan->channel]); + chip->int_enabled[chan->channel] = true; + } + +error_ret: + mutex_unlock(&chip->state_lock); + + return ret; +} + +static int ad7150_read_event_value(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, + enum iio_event_info info, + int *val, int *val2) +{ + struct ad7150_chip_info *chip = iio_priv(indio_dev); + int rising = (dir == IIO_EV_DIR_RISING); + + /* Complex register sharing going on here */ + switch (info) { + case IIO_EV_INFO_VALUE: + switch (type) { + case IIO_EV_TYPE_THRESH_ADAPTIVE: + *val = chip->thresh_sensitivity[rising][chan->channel]; + return IIO_VAL_INT; + case IIO_EV_TYPE_THRESH: + *val = chip->threshold[rising][chan->channel]; + return IIO_VAL_INT; + default: + return -EINVAL; + } + case IIO_EV_INFO_TIMEOUT: + *val = 0; + *val2 = chip->thresh_timeout[rising][chan->channel] * 10000; + return IIO_VAL_INT_PLUS_MICRO; + default: + return -EINVAL; + } +} + +static int ad7150_write_event_value(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + enum iio_event_type type, + enum iio_event_direction dir, + enum iio_event_info info, + int val, int val2) +{ + int ret; + struct ad7150_chip_info *chip = iio_priv(indio_dev); + int rising = (dir == IIO_EV_DIR_RISING); + + mutex_lock(&chip->state_lock); + switch (info) { + case IIO_EV_INFO_VALUE: + switch (type) { + case IIO_EV_TYPE_THRESH_ADAPTIVE: + chip->thresh_sensitivity[rising][chan->channel] = val; + break; + case IIO_EV_TYPE_THRESH: + chip->threshold[rising][chan->channel] = val; + break; + default: + ret = -EINVAL; + goto error_ret; + } + break; + case IIO_EV_INFO_TIMEOUT: { + /* + * Raw timeout is in cycles of 10 msecs as long as both + * channels are enabled. + * In terms of INT_PLUS_MICRO, that is in units of 10,000 + */ + int timeout = val2 / 10000; + + if (val != 0 || timeout < 0 || timeout > 15 || val2 % 10000) { + ret = -EINVAL; + goto error_ret; + } + + chip->thresh_timeout[rising][chan->channel] = timeout; + break; + } + default: + ret = -EINVAL; + goto error_ret; + } + + /* write back if active */ + ret = ad7150_write_event_params(indio_dev, chan->channel, type, dir); + +error_ret: + mutex_unlock(&chip->state_lock); + return ret; +} + +static const struct iio_event_spec ad7150_events[] = { + { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_RISING, + .mask_separate = BIT(IIO_EV_INFO_VALUE) | + BIT(IIO_EV_INFO_ENABLE), + }, { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_FALLING, + .mask_separate = BIT(IIO_EV_INFO_VALUE) | + BIT(IIO_EV_INFO_ENABLE), + }, { + .type = IIO_EV_TYPE_THRESH_ADAPTIVE, + .dir = IIO_EV_DIR_RISING, + .mask_separate = BIT(IIO_EV_INFO_VALUE) | + BIT(IIO_EV_INFO_ENABLE) | + BIT(IIO_EV_INFO_TIMEOUT), + }, { + .type = IIO_EV_TYPE_THRESH_ADAPTIVE, + .dir = IIO_EV_DIR_FALLING, + .mask_separate = BIT(IIO_EV_INFO_VALUE) | + BIT(IIO_EV_INFO_ENABLE) | + BIT(IIO_EV_INFO_TIMEOUT), + }, +}; + +#define AD7150_CAPACITANCE_CHAN(_chan) { \ + .type = IIO_CAPACITANCE, \ + .indexed = 1, \ + .channel = _chan, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_AVERAGE_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_OFFSET), \ + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),\ + .event_spec = ad7150_events, \ + .num_event_specs = ARRAY_SIZE(ad7150_events), \ + } + +#define AD7150_CAPACITANCE_CHAN_NO_IRQ(_chan) { \ + .type = IIO_CAPACITANCE, \ + .indexed = 1, \ + .channel = _chan, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_AVERAGE_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_OFFSET), \ + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),\ + } + +static const struct iio_chan_spec ad7150_channels[] = { + AD7150_CAPACITANCE_CHAN(0), + AD7150_CAPACITANCE_CHAN(1), +}; + +static const struct iio_chan_spec ad7150_channels_no_irq[] = { + AD7150_CAPACITANCE_CHAN_NO_IRQ(0), + AD7150_CAPACITANCE_CHAN_NO_IRQ(1), +}; + +static const struct iio_chan_spec ad7151_channels[] = { + AD7150_CAPACITANCE_CHAN(0), +}; + +static const struct iio_chan_spec ad7151_channels_no_irq[] = { + AD7150_CAPACITANCE_CHAN_NO_IRQ(0), +}; + +static irqreturn_t __ad7150_event_handler(void *private, u8 status_mask, + int channel) +{ + struct iio_dev *indio_dev = private; + struct ad7150_chip_info *chip = iio_priv(indio_dev); + s64 timestamp = iio_get_time_ns(indio_dev); + int int_status; + + int_status = i2c_smbus_read_byte_data(chip->client, AD7150_STATUS_REG); + if (int_status < 0) + return IRQ_HANDLED; + + if (!(int_status & status_mask)) + return IRQ_HANDLED; + + iio_push_event(indio_dev, + IIO_UNMOD_EVENT_CODE(IIO_CAPACITANCE, channel, + chip->type, chip->dir), + timestamp); + + return IRQ_HANDLED; +} + +static irqreturn_t ad7150_event_handler_ch1(int irq, void *private) +{ + return __ad7150_event_handler(private, AD7150_STATUS_OUT1, 0); +} + +static irqreturn_t ad7150_event_handler_ch2(int irq, void *private) +{ + return __ad7150_event_handler(private, AD7150_STATUS_OUT2, 1); +} + +static IIO_CONST_ATTR(in_capacitance_thresh_adaptive_timeout_available, + "[0 0.01 0.15]"); + +static struct attribute *ad7150_event_attributes[] = { + &iio_const_attr_in_capacitance_thresh_adaptive_timeout_available + .dev_attr.attr, + NULL, +}; + +static const struct attribute_group ad7150_event_attribute_group = { + .attrs = ad7150_event_attributes, + .name = "events", +}; + +static const struct iio_info ad7150_info = { + .event_attrs = &ad7150_event_attribute_group, + .read_raw = &ad7150_read_raw, + .read_event_config = &ad7150_read_event_config, + .write_event_config = &ad7150_write_event_config, + .read_event_value = &ad7150_read_event_value, + .write_event_value = &ad7150_write_event_value, +}; + +static const struct iio_info ad7150_info_no_irq = { + .read_raw = &ad7150_read_raw, +}; + +static void ad7150_reg_disable(void *data) +{ + struct regulator *reg = data; + + regulator_disable(reg); +} + +static int ad7150_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct ad7150_chip_info *chip; + struct iio_dev *indio_dev; + struct regulator *reg; + int ret; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip)); + if (!indio_dev) + return -ENOMEM; + + chip = iio_priv(indio_dev); + mutex_init(&chip->state_lock); + chip->client = client; + + indio_dev->name = id->name; + + indio_dev->modes = INDIO_DIRECT_MODE; + + reg = devm_regulator_get(&client->dev, "vdd"); + if (IS_ERR(reg)) + return PTR_ERR(reg); + + ret = regulator_enable(reg); + if (ret) + return ret; + + ret = devm_add_action_or_reset(&client->dev, ad7150_reg_disable, reg); + if (ret) + return ret; + + chip->interrupts[0] = fwnode_irq_get(dev_fwnode(&client->dev), 0); + if (chip->interrupts[0] < 0) + return chip->interrupts[0]; + if (id->driver_data == AD7150) { + chip->interrupts[1] = fwnode_irq_get(dev_fwnode(&client->dev), 1); + if (chip->interrupts[1] < 0) + return chip->interrupts[1]; + } + if (chip->interrupts[0] && + (id->driver_data == AD7151 || chip->interrupts[1])) { + irq_set_status_flags(chip->interrupts[0], IRQ_NOAUTOEN); + ret = devm_request_threaded_irq(&client->dev, + chip->interrupts[0], + NULL, + &ad7150_event_handler_ch1, + IRQF_TRIGGER_RISING | + IRQF_ONESHOT, + "ad7150_irq1", + indio_dev); + if (ret) + return ret; + + indio_dev->info = &ad7150_info; + switch (id->driver_data) { + case AD7150: + indio_dev->channels = ad7150_channels; + indio_dev->num_channels = ARRAY_SIZE(ad7150_channels); + irq_set_status_flags(chip->interrupts[1], IRQ_NOAUTOEN); + ret = devm_request_threaded_irq(&client->dev, + chip->interrupts[1], + NULL, + &ad7150_event_handler_ch2, + IRQF_TRIGGER_RISING | + IRQF_ONESHOT, + "ad7150_irq2", + indio_dev); + if (ret) + return ret; + break; + case AD7151: + indio_dev->channels = ad7151_channels; + indio_dev->num_channels = ARRAY_SIZE(ad7151_channels); + break; + default: + return -EINVAL; + } + + } else { + indio_dev->info = &ad7150_info_no_irq; + switch (id->driver_data) { + case AD7150: + indio_dev->channels = ad7150_channels_no_irq; + indio_dev->num_channels = + ARRAY_SIZE(ad7150_channels_no_irq); + break; + case AD7151: + indio_dev->channels = ad7151_channels_no_irq; + indio_dev->num_channels = + ARRAY_SIZE(ad7151_channels_no_irq); + break; + default: + return -EINVAL; + } + } + + return devm_iio_device_register(indio_dev->dev.parent, indio_dev); +} + +static const struct i2c_device_id ad7150_id[] = { + { "ad7150", AD7150 }, + { "ad7151", AD7151 }, + { "ad7156", AD7150 }, + {} +}; + +MODULE_DEVICE_TABLE(i2c, ad7150_id); + +static const struct of_device_id ad7150_of_match[] = { + { "adi,ad7150" }, + { "adi,ad7151" }, + { "adi,ad7156" }, + {} +}; +static struct i2c_driver ad7150_driver = { + .driver = { + .name = "ad7150", + .of_match_table = ad7150_of_match, + }, + .probe = ad7150_probe, + .id_table = ad7150_id, +}; +module_i2c_driver(ad7150_driver); + +MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>"); +MODULE_DESCRIPTION("Analog Devices AD7150/1/6 capacitive sensor driver"); +MODULE_LICENSE("GPL v2"); |