1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * STMicroelectronics sensors buffer library driver 4 * 5 * Copyright 2012-2013 STMicroelectronics Inc. 6 * 7 * Denis Ciocca <denis.ciocca@st.com> 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/module.h> 12 #include <linux/iio/iio.h> 13 #include <linux/iio/trigger.h> 14 #include <linux/interrupt.h> 15 #include <linux/iio/buffer.h> 16 #include <linux/iio/trigger_consumer.h> 17 #include <linux/irqreturn.h> 18 #include <linux/regmap.h> 19 20 #include <linux/iio/common/st_sensors.h> 21 22 23 static int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf) 24 { 25 struct st_sensor_data *sdata = iio_priv(indio_dev); 26 unsigned int num_data_channels = sdata->num_data_channels; 27 int i; 28 29 for_each_set_bit(i, indio_dev->active_scan_mask, num_data_channels) { 30 const struct iio_chan_spec *channel = &indio_dev->channels[i]; 31 unsigned int bytes_to_read = 32 DIV_ROUND_UP(channel->scan_type.realbits + 33 channel->scan_type.shift, 8); 34 unsigned int storage_bytes = 35 channel->scan_type.storagebits >> 3; 36 37 buf = PTR_ALIGN(buf, storage_bytes); 38 if (regmap_bulk_read(sdata->regmap, channel->address, 39 buf, bytes_to_read) < 0) 40 return -EIO; 41 42 /* Advance the buffer pointer */ 43 buf += storage_bytes; 44 } 45 46 return 0; 47 } 48 49 irqreturn_t st_sensors_trigger_handler(int irq, void *p) 50 { 51 int len; 52 struct iio_poll_func *pf = p; 53 struct iio_dev *indio_dev = pf->indio_dev; 54 struct st_sensor_data *sdata = iio_priv(indio_dev); 55 s64 timestamp; 56 57 /* 58 * If we do timestamping here, do it before reading the values, because 59 * once we've read the values, new interrupts can occur (when using 60 * the hardware trigger) and the hw_timestamp may get updated. 61 * By storing it in a local variable first, we are safe. 62 */ 63 if (iio_trigger_using_own(indio_dev)) 64 timestamp = sdata->hw_timestamp; 65 else 66 timestamp = iio_get_time_ns(indio_dev); 67 68 len = st_sensors_get_buffer_element(indio_dev, sdata->buffer_data); 69 if (len < 0) 70 goto st_sensors_get_buffer_element_error; 71 72 iio_push_to_buffers_with_timestamp(indio_dev, sdata->buffer_data, 73 timestamp); 74 75 st_sensors_get_buffer_element_error: 76 iio_trigger_notify_done(indio_dev->trig); 77 78 return IRQ_HANDLED; 79 } 80 EXPORT_SYMBOL(st_sensors_trigger_handler); 81 82 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>"); 83 MODULE_DESCRIPTION("STMicroelectronics ST-sensors buffer"); 84 MODULE_LICENSE("GPL v2"); 85