1 /* 2 * STMicroelectronics magnetometers driver 3 * 4 * Copyright 2012-2013 STMicroelectronics Inc. 5 * 6 * Denis Ciocca <denis.ciocca@st.com> 7 * 8 * Licensed under the GPL-2. 9 */ 10 11 #include <linux/module.h> 12 #include <linux/kernel.h> 13 #include <linux/slab.h> 14 #include <linux/stat.h> 15 #include <linux/interrupt.h> 16 #include <linux/i2c.h> 17 #include <linux/delay.h> 18 #include <linux/iio/iio.h> 19 #include <linux/iio/buffer.h> 20 #include <linux/iio/trigger_consumer.h> 21 #include <linux/iio/triggered_buffer.h> 22 23 #include <linux/iio/common/st_sensors.h> 24 #include "st_magn.h" 25 26 static int st_magn_buffer_preenable(struct iio_dev *indio_dev) 27 { 28 return st_sensors_set_enable(indio_dev, true); 29 } 30 31 static int st_magn_buffer_postenable(struct iio_dev *indio_dev) 32 { 33 int err; 34 struct st_sensor_data *mdata = iio_priv(indio_dev); 35 36 mdata->buffer_data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL); 37 if (mdata->buffer_data == NULL) { 38 err = -ENOMEM; 39 goto allocate_memory_error; 40 } 41 42 err = iio_triggered_buffer_postenable(indio_dev); 43 if (err < 0) 44 goto st_magn_buffer_postenable_error; 45 46 return err; 47 48 st_magn_buffer_postenable_error: 49 kfree(mdata->buffer_data); 50 allocate_memory_error: 51 return err; 52 } 53 54 static int st_magn_buffer_predisable(struct iio_dev *indio_dev) 55 { 56 int err; 57 struct st_sensor_data *mdata = iio_priv(indio_dev); 58 59 err = iio_triggered_buffer_predisable(indio_dev); 60 if (err < 0) 61 goto st_magn_buffer_predisable_error; 62 63 err = st_sensors_set_enable(indio_dev, false); 64 65 st_magn_buffer_predisable_error: 66 kfree(mdata->buffer_data); 67 return err; 68 } 69 70 static const struct iio_buffer_setup_ops st_magn_buffer_setup_ops = { 71 .preenable = &st_magn_buffer_preenable, 72 .postenable = &st_magn_buffer_postenable, 73 .predisable = &st_magn_buffer_predisable, 74 }; 75 76 int st_magn_allocate_ring(struct iio_dev *indio_dev) 77 { 78 return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, 79 &st_sensors_trigger_handler, &st_magn_buffer_setup_ops); 80 } 81 82 void st_magn_deallocate_ring(struct iio_dev *indio_dev) 83 { 84 iio_triggered_buffer_cleanup(indio_dev); 85 } 86 87 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>"); 88 MODULE_DESCRIPTION("STMicroelectronics magnetometers buffer"); 89 MODULE_LICENSE("GPL v2"); 90