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