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path: root/drivers/iio/humidity/hts221_buffer.c
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Diffstat (limited to 'drivers/iio/humidity/hts221_buffer.c')
-rw-r--r--drivers/iio/humidity/hts221_buffer.c168
1 files changed, 168 insertions, 0 deletions
diff --git a/drivers/iio/humidity/hts221_buffer.c b/drivers/iio/humidity/hts221_buffer.c
new file mode 100644
index 000000000000..72ddcdac21a2
--- /dev/null
+++ b/drivers/iio/humidity/hts221_buffer.c
@@ -0,0 +1,168 @@
+/*
+ * 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/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 "hts221.h"
+
+#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 hts221_config_drdy(hw, state);
+}
+
+static const struct iio_trigger_ops hts221_trigger_ops = {
+ .owner = THIS_MODULE,
+ .set_trigger_state = hts221_trig_set_state,
+};
+
+static irqreturn_t hts221_trigger_handler_thread(int irq, void *private)
+{
+ struct hts221_hw *hw = (struct hts221_hw *)private;
+ u8 status;
+ int err;
+
+ err = hw->tf->read(hw->dev, HTS221_REG_STATUS_ADDR, sizeof(status),
+ &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);
+ 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;
+ default:
+ dev_info(hw->dev,
+ "mode %lx unsupported, using IRQF_TRIGGER_RISING\n",
+ irq_type);
+ irq_type = IRQF_TRIGGER_RISING;
+ break;
+ }
+
+ 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_power_on(iio_priv(iio_dev));
+}
+
+static int hts221_buffer_postdisable(struct iio_dev *iio_dev)
+{
+ return hts221_power_off(iio_priv(iio_dev));
+}
+
+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)
+{
+ u8 buffer[ALIGN(2 * HTS221_DATA_SIZE, sizeof(s64)) + sizeof(s64)];
+ 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 = hw->tf->read(hw->dev, ch->address, HTS221_DATA_SIZE,
+ buffer);
+ if (err < 0)
+ goto out;
+
+ /* temperature data */
+ ch = &iio_dev->channels[HTS221_SENSOR_T];
+ err = hw->tf->read(hw->dev, ch->address, HTS221_DATA_SIZE,
+ buffer + HTS221_DATA_SIZE);
+ if (err < 0)
+ goto out;
+
+ iio_push_to_buffers_with_timestamp(iio_dev, buffer,
+ 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");