diff options
Diffstat (limited to 'drivers/iio/proximity/sx_common.c')
-rw-r--r-- | drivers/iio/proximity/sx_common.c | 573 |
1 files changed, 573 insertions, 0 deletions
diff --git a/drivers/iio/proximity/sx_common.c b/drivers/iio/proximity/sx_common.c new file mode 100644 index 0000000000..fe07d1444a --- /dev/null +++ b/drivers/iio/proximity/sx_common.c @@ -0,0 +1,573 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2021 Google LLC. + * + * Common part of most Semtech SAR sensor. + */ + +#include <linux/bitops.h> +#include <linux/byteorder/generic.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/export.h> +#include <linux/interrupt.h> +#include <linux/irqreturn.h> +#include <linux/i2c.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> +#include <vdso/bits.h> + +#include <linux/iio/buffer.h> +#include <linux/iio/events.h> +#include <linux/iio/iio.h> +#include <linux/iio/trigger.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/trigger_consumer.h> + +#include "sx_common.h" + +/* All Semtech SAR sensors have IRQ bit in the same order. */ +#define SX_COMMON_CONVDONE_IRQ BIT(0) +#define SX_COMMON_FAR_IRQ BIT(2) +#define SX_COMMON_CLOSE_IRQ BIT(3) + +const struct iio_event_spec sx_common_events[3] = { + { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_RISING, + .mask_shared_by_all = BIT(IIO_EV_INFO_PERIOD), + }, + { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_FALLING, + .mask_shared_by_all = BIT(IIO_EV_INFO_PERIOD), + }, + { + .type = IIO_EV_TYPE_THRESH, + .dir = IIO_EV_DIR_EITHER, + .mask_separate = BIT(IIO_EV_INFO_ENABLE) | + BIT(IIO_EV_INFO_HYSTERESIS) | + BIT(IIO_EV_INFO_VALUE), + }, +}; +EXPORT_SYMBOL_NS_GPL(sx_common_events, SEMTECH_PROX); + +static irqreturn_t sx_common_irq_handler(int irq, void *private) +{ + struct iio_dev *indio_dev = private; + struct sx_common_data *data = iio_priv(indio_dev); + + if (data->trigger_enabled) + iio_trigger_poll(data->trig); + + /* + * Even if no event is enabled, we need to wake the thread to clear the + * interrupt state by reading SX_COMMON_REG_IRQ_SRC. + * It is not possible to do that here because regmap_read takes a mutex. + */ + return IRQ_WAKE_THREAD; +} + +static void sx_common_push_events(struct iio_dev *indio_dev) +{ + int ret; + unsigned int val, chan; + struct sx_common_data *data = iio_priv(indio_dev); + s64 timestamp = iio_get_time_ns(indio_dev); + unsigned long prox_changed; + + /* Read proximity state on all channels */ + ret = regmap_read(data->regmap, data->chip_info->reg_stat, &val); + if (ret) { + dev_err(&data->client->dev, "i2c transfer error in irq\n"); + return; + } + + val >>= data->chip_info->stat_offset; + + /* + * Only iterate over channels with changes on proximity status that have + * events enabled. + */ + prox_changed = (data->chan_prox_stat ^ val) & data->chan_event; + + for_each_set_bit(chan, &prox_changed, data->chip_info->num_channels) { + int dir; + u64 ev; + + dir = (val & BIT(chan)) ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING; + ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, chan, + IIO_EV_TYPE_THRESH, dir); + + iio_push_event(indio_dev, ev, timestamp); + } + data->chan_prox_stat = val; +} + +static int sx_common_enable_irq(struct sx_common_data *data, unsigned int irq) +{ + if (!data->client->irq) + return 0; + return regmap_update_bits(data->regmap, data->chip_info->reg_irq_msk, + irq << data->chip_info->irq_msk_offset, + irq << data->chip_info->irq_msk_offset); +} + +static int sx_common_disable_irq(struct sx_common_data *data, unsigned int irq) +{ + if (!data->client->irq) + return 0; + return regmap_update_bits(data->regmap, data->chip_info->reg_irq_msk, + irq << data->chip_info->irq_msk_offset, 0); +} + +static int sx_common_update_chan_en(struct sx_common_data *data, + unsigned long chan_read, + unsigned long chan_event) +{ + int ret; + unsigned long channels = chan_read | chan_event; + + if ((data->chan_read | data->chan_event) != channels) { + ret = regmap_update_bits(data->regmap, + data->chip_info->reg_enable_chan, + data->chip_info->mask_enable_chan, + channels); + if (ret) + return ret; + } + data->chan_read = chan_read; + data->chan_event = chan_event; + return 0; +} + +static int sx_common_get_read_channel(struct sx_common_data *data, int channel) +{ + return sx_common_update_chan_en(data, data->chan_read | BIT(channel), + data->chan_event); +} + +static int sx_common_put_read_channel(struct sx_common_data *data, int channel) +{ + return sx_common_update_chan_en(data, data->chan_read & ~BIT(channel), + data->chan_event); +} + +static int sx_common_get_event_channel(struct sx_common_data *data, int channel) +{ + return sx_common_update_chan_en(data, data->chan_read, + data->chan_event | BIT(channel)); +} + +static int sx_common_put_event_channel(struct sx_common_data *data, int channel) +{ + return sx_common_update_chan_en(data, data->chan_read, + data->chan_event & ~BIT(channel)); +} + +/** + * sx_common_read_proximity() - Read raw proximity value. + * @data: Internal data + * @chan: Channel to read + * @val: pointer to return read value. + * + * Request a conversion, wait for the sensor to be ready and + * return the raw proximity value. + */ +int sx_common_read_proximity(struct sx_common_data *data, + const struct iio_chan_spec *chan, int *val) +{ + int ret; + __be16 rawval; + + mutex_lock(&data->mutex); + + ret = sx_common_get_read_channel(data, chan->channel); + if (ret) + goto out; + + ret = sx_common_enable_irq(data, SX_COMMON_CONVDONE_IRQ); + if (ret) + goto out_put_channel; + + mutex_unlock(&data->mutex); + + if (data->client->irq) { + ret = wait_for_completion_interruptible(&data->completion); + reinit_completion(&data->completion); + } else { + ret = data->chip_info->ops.wait_for_sample(data); + } + + mutex_lock(&data->mutex); + + if (ret) + goto out_disable_irq; + + ret = data->chip_info->ops.read_prox_data(data, chan, &rawval); + if (ret) + goto out_disable_irq; + + *val = sign_extend32(be16_to_cpu(rawval), chan->scan_type.realbits - 1); + + ret = sx_common_disable_irq(data, SX_COMMON_CONVDONE_IRQ); + if (ret) + goto out_put_channel; + + ret = sx_common_put_read_channel(data, chan->channel); + if (ret) + goto out; + + mutex_unlock(&data->mutex); + + return IIO_VAL_INT; + +out_disable_irq: + sx_common_disable_irq(data, SX_COMMON_CONVDONE_IRQ); +out_put_channel: + sx_common_put_read_channel(data, chan->channel); +out: + mutex_unlock(&data->mutex); + + return ret; +} +EXPORT_SYMBOL_NS_GPL(sx_common_read_proximity, SEMTECH_PROX); + +/** + * sx_common_read_event_config() - Configure event setting. + * @indio_dev: iio device object + * @chan: Channel to read + * @type: Type of event (unused) + * @dir: Direction of event (unused) + * + * return if the given channel is used for event gathering. + */ +int sx_common_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 sx_common_data *data = iio_priv(indio_dev); + + return !!(data->chan_event & BIT(chan->channel)); +} +EXPORT_SYMBOL_NS_GPL(sx_common_read_event_config, SEMTECH_PROX); + +/** + * sx_common_write_event_config() - Configure event setting. + * @indio_dev: iio device object + * @chan: Channel to enable + * @type: Type of event (unused) + * @dir: Direction of event (unused) + * @state: State of the event. + * + * Enable/Disable event on a given channel. + */ +int sx_common_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 sx_common_data *data = iio_priv(indio_dev); + unsigned int eventirq = SX_COMMON_FAR_IRQ | SX_COMMON_CLOSE_IRQ; + int ret; + + /* If the state hasn't changed, there's nothing to do. */ + if (!!(data->chan_event & BIT(chan->channel)) == state) + return 0; + + mutex_lock(&data->mutex); + if (state) { + ret = sx_common_get_event_channel(data, chan->channel); + if (ret) + goto out_unlock; + if (!(data->chan_event & ~BIT(chan->channel))) { + ret = sx_common_enable_irq(data, eventirq); + if (ret) + sx_common_put_event_channel(data, chan->channel); + } + } else { + ret = sx_common_put_event_channel(data, chan->channel); + if (ret) + goto out_unlock; + if (!data->chan_event) { + ret = sx_common_disable_irq(data, eventirq); + if (ret) + sx_common_get_event_channel(data, chan->channel); + } + } + +out_unlock: + mutex_unlock(&data->mutex); + return ret; +} +EXPORT_SYMBOL_NS_GPL(sx_common_write_event_config, SEMTECH_PROX); + +static int sx_common_set_trigger_state(struct iio_trigger *trig, bool state) +{ + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); + struct sx_common_data *data = iio_priv(indio_dev); + int ret = 0; + + mutex_lock(&data->mutex); + + if (state) + ret = sx_common_enable_irq(data, SX_COMMON_CONVDONE_IRQ); + else if (!data->chan_read) + ret = sx_common_disable_irq(data, SX_COMMON_CONVDONE_IRQ); + if (ret) + goto out; + + data->trigger_enabled = state; + +out: + mutex_unlock(&data->mutex); + + return ret; +} + +static const struct iio_trigger_ops sx_common_trigger_ops = { + .set_trigger_state = sx_common_set_trigger_state, +}; + +static irqreturn_t sx_common_irq_thread_handler(int irq, void *private) +{ + struct iio_dev *indio_dev = private; + struct sx_common_data *data = iio_priv(indio_dev); + int ret; + unsigned int val; + + mutex_lock(&data->mutex); + + ret = regmap_read(data->regmap, SX_COMMON_REG_IRQ_SRC, &val); + if (ret) { + dev_err(&data->client->dev, "i2c transfer error in irq\n"); + goto out; + } + + if (val & ((SX_COMMON_FAR_IRQ | SX_COMMON_CLOSE_IRQ) << data->chip_info->irq_msk_offset)) + sx_common_push_events(indio_dev); + + if (val & (SX_COMMON_CONVDONE_IRQ << data->chip_info->irq_msk_offset)) + complete(&data->completion); + +out: + mutex_unlock(&data->mutex); + + return IRQ_HANDLED; +} + +static irqreturn_t sx_common_trigger_handler(int irq, void *private) +{ + struct iio_poll_func *pf = private; + struct iio_dev *indio_dev = pf->indio_dev; + struct sx_common_data *data = iio_priv(indio_dev); + __be16 val; + int bit, ret, i = 0; + + mutex_lock(&data->mutex); + + for_each_set_bit(bit, indio_dev->active_scan_mask, + indio_dev->masklength) { + ret = data->chip_info->ops.read_prox_data(data, + &indio_dev->channels[bit], + &val); + if (ret) + goto out; + + data->buffer.channels[i++] = val; + } + + iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer, + pf->timestamp); + +out: + mutex_unlock(&data->mutex); + + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +static int sx_common_buffer_preenable(struct iio_dev *indio_dev) +{ + struct sx_common_data *data = iio_priv(indio_dev); + unsigned long channels = 0; + int bit, ret; + + mutex_lock(&data->mutex); + for_each_set_bit(bit, indio_dev->active_scan_mask, + indio_dev->masklength) + __set_bit(indio_dev->channels[bit].channel, &channels); + + ret = sx_common_update_chan_en(data, channels, data->chan_event); + mutex_unlock(&data->mutex); + return ret; +} + +static int sx_common_buffer_postdisable(struct iio_dev *indio_dev) +{ + struct sx_common_data *data = iio_priv(indio_dev); + int ret; + + mutex_lock(&data->mutex); + ret = sx_common_update_chan_en(data, 0, data->chan_event); + mutex_unlock(&data->mutex); + return ret; +} + +static const struct iio_buffer_setup_ops sx_common_buffer_setup_ops = { + .preenable = sx_common_buffer_preenable, + .postdisable = sx_common_buffer_postdisable, +}; + +void sx_common_get_raw_register_config(struct device *dev, + struct sx_common_reg_default *reg_def) +{ +#ifdef CONFIG_ACPI + struct acpi_device *adev = ACPI_COMPANION(dev); + u32 raw = 0, ret; + char prop[80]; + + if (!reg_def->property || !adev) + return; + + snprintf(prop, ARRAY_SIZE(prop), "%s,reg_%s", acpi_device_hid(adev), reg_def->property); + ret = device_property_read_u32(dev, prop, &raw); + if (ret) + return; + + reg_def->def = raw; +#endif +} +EXPORT_SYMBOL_NS_GPL(sx_common_get_raw_register_config, SEMTECH_PROX); + +#define SX_COMMON_SOFT_RESET 0xde + +static int sx_common_init_device(struct device *dev, struct iio_dev *indio_dev) +{ + struct sx_common_data *data = iio_priv(indio_dev); + struct sx_common_reg_default tmp; + const struct sx_common_reg_default *initval; + int ret; + unsigned int i, val; + + ret = regmap_write(data->regmap, data->chip_info->reg_reset, + SX_COMMON_SOFT_RESET); + if (ret) + return ret; + + usleep_range(1000, 2000); /* power-up time is ~1ms. */ + + /* Clear reset interrupt state by reading SX_COMMON_REG_IRQ_SRC. */ + ret = regmap_read(data->regmap, SX_COMMON_REG_IRQ_SRC, &val); + if (ret) + return ret; + + /* Program defaults from constant or BIOS. */ + for (i = 0; i < data->chip_info->num_default_regs; i++) { + initval = data->chip_info->ops.get_default_reg(dev, i, &tmp); + ret = regmap_write(data->regmap, initval->reg, initval->def); + if (ret) + return ret; + } + + return data->chip_info->ops.init_compensation(indio_dev); +} + +/** + * sx_common_probe() - Common setup for Semtech SAR sensor + * @client: I2C client object + * @chip_info: Semtech sensor chip information. + * @regmap_config: Sensor registers map configuration. + */ +int sx_common_probe(struct i2c_client *client, + const struct sx_common_chip_info *chip_info, + const struct regmap_config *regmap_config) +{ + static const char * const regulator_names[] = { "vdd", "svdd" }; + struct device *dev = &client->dev; + struct iio_dev *indio_dev; + struct sx_common_data *data; + int ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + data = iio_priv(indio_dev); + + data->chip_info = chip_info; + data->client = client; + mutex_init(&data->mutex); + init_completion(&data->completion); + + data->regmap = devm_regmap_init_i2c(client, regmap_config); + if (IS_ERR(data->regmap)) + return dev_err_probe(dev, PTR_ERR(data->regmap), + "Could init register map\n"); + + ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(regulator_names), + regulator_names); + if (ret) + return dev_err_probe(dev, ret, "Unable to get regulators\n"); + + /* Must wait for Tpor time after initial power up */ + usleep_range(1000, 1100); + + ret = data->chip_info->ops.check_whoami(dev, indio_dev); + if (ret) + return dev_err_probe(dev, ret, "error reading WHOAMI\n"); + + indio_dev->modes = INDIO_DIRECT_MODE; + + indio_dev->channels = data->chip_info->iio_channels; + indio_dev->num_channels = data->chip_info->num_iio_channels; + indio_dev->info = &data->chip_info->iio_info; + + i2c_set_clientdata(client, indio_dev); + + ret = sx_common_init_device(dev, indio_dev); + if (ret) + return dev_err_probe(dev, ret, "Unable to initialize sensor\n"); + + if (client->irq) { + ret = devm_request_threaded_irq(dev, client->irq, + sx_common_irq_handler, + sx_common_irq_thread_handler, + IRQF_ONESHOT, + "sx_event", indio_dev); + if (ret) + return dev_err_probe(dev, ret, "No IRQ\n"); + + data->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", + indio_dev->name, + iio_device_id(indio_dev)); + if (!data->trig) + return -ENOMEM; + + data->trig->ops = &sx_common_trigger_ops; + iio_trigger_set_drvdata(data->trig, indio_dev); + + ret = devm_iio_trigger_register(dev, data->trig); + if (ret) + return ret; + } + + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, + iio_pollfunc_store_time, + sx_common_trigger_handler, + &sx_common_buffer_setup_ops); + if (ret) + return ret; + + return devm_iio_device_register(dev, indio_dev); +} +EXPORT_SYMBOL_NS_GPL(sx_common_probe, SEMTECH_PROX); + +MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>"); +MODULE_DESCRIPTION("Common functions and structures for Semtech sensor"); +MODULE_LICENSE("GPL v2"); |