1 /*
2 * STMicroelectronics sensors buffer library 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/kernel.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/iio/iio.h>
15 #include <linux/iio/trigger.h>
16 #include <linux/interrupt.h>
17 #include <linux/iio/buffer.h>
18 #include <linux/iio/trigger_consumer.h>
19 #include <linux/iio/triggered_buffer.h>
20 #include <linux/irqreturn.h>
21
22 #include <linux/iio/common/st_sensors.h>
23
24
st_sensors_get_buffer_element(struct iio_dev * indio_dev,u8 * buf)25 int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
26 {
27 u8 *addr;
28 int i, n = 0, len;
29 struct st_sensor_data *sdata = iio_priv(indio_dev);
30 unsigned int num_data_channels = sdata->num_data_channels;
31 unsigned int byte_for_channel =
32 indio_dev->channels[0].scan_type.storagebits >> 3;
33
34 addr = kmalloc(num_data_channels, GFP_KERNEL);
35 if (!addr) {
36 len = -ENOMEM;
37 goto st_sensors_get_buffer_element_error;
38 }
39
40 for (i = 0; i < num_data_channels; i++) {
41 if (test_bit(i, indio_dev->active_scan_mask)) {
42 addr[n] = indio_dev->channels[i].address;
43 n++;
44 }
45 }
46 switch (n) {
47 case 1:
48 len = sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
49 addr[0], byte_for_channel, buf, sdata->multiread_bit);
50 break;
51 case 2:
52 if ((addr[1] - addr[0]) == byte_for_channel) {
53 len = sdata->tf->read_multiple_byte(&sdata->tb,
54 sdata->dev, addr[0], byte_for_channel * n,
55 buf, sdata->multiread_bit);
56 } else {
57 u8 *rx_array;
58 rx_array = kmalloc(byte_for_channel * num_data_channels,
59 GFP_KERNEL);
60 if (!rx_array) {
61 len = -ENOMEM;
62 goto st_sensors_free_memory;
63 }
64
65 len = sdata->tf->read_multiple_byte(&sdata->tb,
66 sdata->dev, addr[0],
67 byte_for_channel * num_data_channels,
68 rx_array, sdata->multiread_bit);
69 if (len < 0) {
70 kfree(rx_array);
71 goto st_sensors_free_memory;
72 }
73
74 for (i = 0; i < n * byte_for_channel; i++) {
75 if (i < n)
76 buf[i] = rx_array[i];
77 else
78 buf[i] = rx_array[n + i];
79 }
80 kfree(rx_array);
81 len = byte_for_channel * n;
82 }
83 break;
84 case 3:
85 len = sdata->tf->read_multiple_byte(&sdata->tb, sdata->dev,
86 addr[0], byte_for_channel * num_data_channels,
87 buf, sdata->multiread_bit);
88 break;
89 default:
90 len = -EINVAL;
91 goto st_sensors_free_memory;
92 }
93 if (len != byte_for_channel * n) {
94 len = -EIO;
95 goto st_sensors_free_memory;
96 }
97
98 st_sensors_free_memory:
99 kfree(addr);
100 st_sensors_get_buffer_element_error:
101 return len;
102 }
103 EXPORT_SYMBOL(st_sensors_get_buffer_element);
104
st_sensors_trigger_handler(int irq,void * p)105 irqreturn_t st_sensors_trigger_handler(int irq, void *p)
106 {
107 int len;
108 struct iio_poll_func *pf = p;
109 struct iio_dev *indio_dev = pf->indio_dev;
110 struct st_sensor_data *sdata = iio_priv(indio_dev);
111
112 len = st_sensors_get_buffer_element(indio_dev, sdata->buffer_data);
113 if (len < 0)
114 goto st_sensors_get_buffer_element_error;
115
116 iio_push_to_buffers_with_timestamp(indio_dev, sdata->buffer_data,
117 pf->timestamp);
118
119 st_sensors_get_buffer_element_error:
120 iio_trigger_notify_done(indio_dev->trig);
121
122 return IRQ_HANDLED;
123 }
124 EXPORT_SYMBOL(st_sensors_trigger_handler);
125
126 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
127 MODULE_DESCRIPTION("STMicroelectronics ST-sensors buffer");
128 MODULE_LICENSE("GPL v2");
129