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/slab.h> 13 #include <linux/iio/iio.h> 14 #include <linux/iio/trigger.h> 15 #include <linux/interrupt.h> 16 #include <linux/iio/buffer.h> 17 #include <linux/iio/trigger_consumer.h> 18 #include <linux/iio/triggered_buffer.h> 19 #include <linux/irqreturn.h> 20 21 #include <linux/iio/common/st_sensors.h> 22 23 24 static int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf) 25 { 26 int i; 27 struct st_sensor_data *sdata = iio_priv(indio_dev); 28 unsigned int num_data_channels = sdata->num_data_channels; 29 30 for_each_set_bit(i, indio_dev->active_scan_mask, num_data_channels) { 31 const struct iio_chan_spec *channel = &indio_dev->channels[i]; 32 unsigned int bytes_to_read = 33 DIV_ROUND_UP(channel->scan_type.realbits + 34 channel->scan_type.shift, 8); 35 unsigned int storage_bytes = 36 channel->scan_type.storagebits >> 3; 37 38 buf = PTR_ALIGN(buf, storage_bytes); 39 if (sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev, 40 channel->address, 41 bytes_to_read, buf, 42 sdata->multiread_bit) < 43 bytes_to_read) 44 return -EIO; 45 46 /* Advance the buffer pointer */ 47 buf += storage_bytes; 48 } 49 50 return 0; 51 } 52 53 irqreturn_t st_sensors_trigger_handler(int irq, void *p) 54 { 55 int len; 56 struct iio_poll_func *pf = p; 57 struct iio_dev *indio_dev = pf->indio_dev; 58 struct st_sensor_data *sdata = iio_priv(indio_dev); 59 s64 timestamp; 60 61 /* 62 * If we do timetamping here, do it before reading the values, because 63 * once we've read the values, new interrupts can occur (when using 64 * the hardware trigger) and the hw_timestamp may get updated. 65 * By storing it in a local variable first, we are safe. 66 */ 67 if (iio_trigger_using_own(indio_dev)) 68 timestamp = sdata->hw_timestamp; 69 else 70 timestamp = iio_get_time_ns(indio_dev); 71 72 len = st_sensors_get_buffer_element(indio_dev, sdata->buffer_data); 73 if (len < 0) 74 goto st_sensors_get_buffer_element_error; 75 76 iio_push_to_buffers_with_timestamp(indio_dev, sdata->buffer_data, 77 timestamp); 78 79 st_sensors_get_buffer_element_error: 80 iio_trigger_notify_done(indio_dev->trig); 81 82 return IRQ_HANDLED; 83 } 84 EXPORT_SYMBOL(st_sensors_trigger_handler); 85 86 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>"); 87 MODULE_DESCRIPTION("STMicroelectronics ST-sensors buffer"); 88 MODULE_LICENSE("GPL v2"); 89