diff options
Diffstat (limited to 'drivers/iio/humidity/hts221_buffer.c')
| -rw-r--r-- | drivers/iio/humidity/hts221_buffer.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/drivers/iio/humidity/hts221_buffer.c b/drivers/iio/humidity/hts221_buffer.c new file mode 100644 index 000000000..910a5d4ea --- /dev/null +++ b/drivers/iio/humidity/hts221_buffer.c @@ -0,0 +1,206 @@ +/* + * STMicroelectronics hts221 sensor driver + * + * Copyright 2016 STMicroelectronics Inc. + * + * Lorenzo Bianconi <lorenzo.bianconi@st.com> + * + * Licensed under the GPL-2. + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/irqreturn.h> +#include <linux/regmap.h> +#include <linux/bitfield.h> + +#include <linux/iio/iio.h> +#include <linux/iio/trigger.h> +#include <linux/iio/events.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/buffer.h> + +#include <linux/platform_data/st_sensors_pdata.h> + +#include "hts221.h" + +#define HTS221_REG_DRDY_HL_ADDR 0x22 +#define HTS221_REG_DRDY_HL_MASK BIT(7) +#define HTS221_REG_DRDY_PP_OD_ADDR 0x22 +#define HTS221_REG_DRDY_PP_OD_MASK BIT(6) +#define HTS221_REG_DRDY_EN_ADDR 0x22 +#define HTS221_REG_DRDY_EN_MASK BIT(2) +#define HTS221_REG_STATUS_ADDR 0x27 +#define HTS221_RH_DRDY_MASK BIT(1) +#define HTS221_TEMP_DRDY_MASK BIT(0) + +static int hts221_trig_set_state(struct iio_trigger *trig, bool state) +{ + struct iio_dev *iio_dev = iio_trigger_get_drvdata(trig); + struct hts221_hw *hw = iio_priv(iio_dev); + + return regmap_update_bits(hw->regmap, HTS221_REG_DRDY_EN_ADDR, + HTS221_REG_DRDY_EN_MASK, + FIELD_PREP(HTS221_REG_DRDY_EN_MASK, state)); +} + +static const struct iio_trigger_ops hts221_trigger_ops = { + .set_trigger_state = hts221_trig_set_state, +}; + +static irqreturn_t hts221_trigger_handler_thread(int irq, void *private) +{ + struct hts221_hw *hw = private; + int err, status; + + err = regmap_read(hw->regmap, HTS221_REG_STATUS_ADDR, &status); + if (err < 0) + return IRQ_HANDLED; + + /* + * H_DA bit (humidity data available) is routed to DRDY line. + * Humidity sample is computed after temperature one. + * Here we can assume data channels are both available if H_DA bit + * is set in status register + */ + if (!(status & HTS221_RH_DRDY_MASK)) + return IRQ_NONE; + + iio_trigger_poll_chained(hw->trig); + + return IRQ_HANDLED; +} + +int hts221_allocate_trigger(struct hts221_hw *hw) +{ + struct iio_dev *iio_dev = iio_priv_to_dev(hw); + bool irq_active_low = false, open_drain = false; + struct device_node *np = hw->dev->of_node; + struct st_sensors_platform_data *pdata; + unsigned long irq_type; + int err; + + irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq)); + + switch (irq_type) { + case IRQF_TRIGGER_HIGH: + case IRQF_TRIGGER_RISING: + break; + case IRQF_TRIGGER_LOW: + case IRQF_TRIGGER_FALLING: + irq_active_low = true; + break; + default: + dev_info(hw->dev, + "mode %lx unsupported, using IRQF_TRIGGER_RISING\n", + irq_type); + irq_type = IRQF_TRIGGER_RISING; + break; + } + + err = regmap_update_bits(hw->regmap, HTS221_REG_DRDY_HL_ADDR, + HTS221_REG_DRDY_HL_MASK, + FIELD_PREP(HTS221_REG_DRDY_HL_MASK, + irq_active_low)); + if (err < 0) + return err; + + pdata = (struct st_sensors_platform_data *)hw->dev->platform_data; + if ((np && of_property_read_bool(np, "drive-open-drain")) || + (pdata && pdata->open_drain)) { + irq_type |= IRQF_SHARED; + open_drain = true; + } + + err = regmap_update_bits(hw->regmap, HTS221_REG_DRDY_PP_OD_ADDR, + HTS221_REG_DRDY_PP_OD_MASK, + FIELD_PREP(HTS221_REG_DRDY_PP_OD_MASK, + open_drain)); + if (err < 0) + return err; + + err = devm_request_threaded_irq(hw->dev, hw->irq, NULL, + hts221_trigger_handler_thread, + irq_type | IRQF_ONESHOT, + hw->name, hw); + if (err) { + dev_err(hw->dev, "failed to request trigger irq %d\n", + hw->irq); + return err; + } + + hw->trig = devm_iio_trigger_alloc(hw->dev, "%s-trigger", + iio_dev->name); + if (!hw->trig) + return -ENOMEM; + + iio_trigger_set_drvdata(hw->trig, iio_dev); + hw->trig->ops = &hts221_trigger_ops; + hw->trig->dev.parent = hw->dev; + iio_dev->trig = iio_trigger_get(hw->trig); + + return devm_iio_trigger_register(hw->dev, hw->trig); +} + +static int hts221_buffer_preenable(struct iio_dev *iio_dev) +{ + return hts221_set_enable(iio_priv(iio_dev), true); +} + +static int hts221_buffer_postdisable(struct iio_dev *iio_dev) +{ + return hts221_set_enable(iio_priv(iio_dev), false); +} + +static const struct iio_buffer_setup_ops hts221_buffer_ops = { + .preenable = hts221_buffer_preenable, + .postenable = iio_triggered_buffer_postenable, + .predisable = iio_triggered_buffer_predisable, + .postdisable = hts221_buffer_postdisable, +}; + +static irqreturn_t hts221_buffer_handler_thread(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *iio_dev = pf->indio_dev; + struct hts221_hw *hw = iio_priv(iio_dev); + struct iio_chan_spec const *ch; + int err; + + /* humidity data */ + ch = &iio_dev->channels[HTS221_SENSOR_H]; + err = regmap_bulk_read(hw->regmap, ch->address, + &hw->scan.channels[0], + sizeof(hw->scan.channels[0])); + if (err < 0) + goto out; + + /* temperature data */ + ch = &iio_dev->channels[HTS221_SENSOR_T]; + err = regmap_bulk_read(hw->regmap, ch->address, + &hw->scan.channels[1], + sizeof(hw->scan.channels[1])); + if (err < 0) + goto out; + + iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan, + iio_get_time_ns(iio_dev)); + +out: + iio_trigger_notify_done(hw->trig); + + return IRQ_HANDLED; +} + +int hts221_allocate_buffers(struct hts221_hw *hw) +{ + return devm_iio_triggered_buffer_setup(hw->dev, iio_priv_to_dev(hw), + NULL, hts221_buffer_handler_thread, + &hts221_buffer_ops); +} + +MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>"); +MODULE_DESCRIPTION("STMicroelectronics hts221 buffer driver"); +MODULE_LICENSE("GPL v2"); |