1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
// SPDX-License-Identifier: GPL-2.0
// SPI driven IR LED device driver
//
// Copyright (c) 2016 Samsung Electronics Co., Ltd.
// Copyright (c) Andi Shyti <andi.shyti@samsung.com>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of_gpio.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>
#include <media/rc-core.h>
#define IR_SPI_DRIVER_NAME "ir-spi"
#define IR_SPI_DEFAULT_FREQUENCY 38000
#define IR_SPI_MAX_BUFSIZE 4096
struct ir_spi_data {
u32 freq;
bool negated;
u16 tx_buf[IR_SPI_MAX_BUFSIZE];
u16 pulse;
u16 space;
struct rc_dev *rc;
struct spi_device *spi;
struct regulator *regulator;
};
static int ir_spi_tx(struct rc_dev *dev,
unsigned int *buffer, unsigned int count)
{
int i;
int ret;
unsigned int len = 0;
struct ir_spi_data *idata = dev->priv;
struct spi_transfer xfer;
/* convert the pulse/space signal to raw binary signal */
for (i = 0; i < count; i++) {
unsigned int periods;
int j;
u16 val;
periods = DIV_ROUND_CLOSEST(buffer[i] * idata->freq, 1000000);
if (len + periods >= IR_SPI_MAX_BUFSIZE)
return -EINVAL;
/*
* the first value in buffer is a pulse, so that 0, 2, 4, ...
* contain a pulse duration. On the contrary, 1, 3, 5, ...
* contain a space duration.
*/
val = (i % 2) ? idata->space : idata->pulse;
for (j = 0; j < periods; j++)
idata->tx_buf[len++] = val;
}
memset(&xfer, 0, sizeof(xfer));
xfer.speed_hz = idata->freq * 16;
xfer.len = len * sizeof(*idata->tx_buf);
xfer.tx_buf = idata->tx_buf;
ret = regulator_enable(idata->regulator);
if (ret)
return ret;
ret = spi_sync_transfer(idata->spi, &xfer, 1);
if (ret)
dev_err(&idata->spi->dev, "unable to deliver the signal\n");
regulator_disable(idata->regulator);
return ret ? ret : count;
}
static int ir_spi_set_tx_carrier(struct rc_dev *dev, u32 carrier)
{
struct ir_spi_data *idata = dev->priv;
if (!carrier)
return -EINVAL;
idata->freq = carrier;
return 0;
}
static int ir_spi_set_duty_cycle(struct rc_dev *dev, u32 duty_cycle)
{
struct ir_spi_data *idata = dev->priv;
int bits = (duty_cycle * 15) / 100;
idata->pulse = GENMASK(bits, 0);
if (idata->negated) {
idata->pulse = ~idata->pulse;
idata->space = 0xffff;
} else {
idata->space = 0;
}
return 0;
}
static int ir_spi_probe(struct spi_device *spi)
{
int ret;
u8 dc;
struct ir_spi_data *idata;
idata = devm_kzalloc(&spi->dev, sizeof(*idata), GFP_KERNEL);
if (!idata)
return -ENOMEM;
idata->regulator = devm_regulator_get(&spi->dev, "irda_regulator");
if (IS_ERR(idata->regulator))
return PTR_ERR(idata->regulator);
idata->rc = devm_rc_allocate_device(&spi->dev, RC_DRIVER_IR_RAW_TX);
if (!idata->rc)
return -ENOMEM;
idata->rc->tx_ir = ir_spi_tx;
idata->rc->s_tx_carrier = ir_spi_set_tx_carrier;
idata->rc->s_tx_duty_cycle = ir_spi_set_duty_cycle;
idata->rc->device_name = "IR SPI";
idata->rc->driver_name = IR_SPI_DRIVER_NAME;
idata->rc->priv = idata;
idata->spi = spi;
idata->negated = of_property_read_bool(spi->dev.of_node,
"led-active-low");
ret = of_property_read_u8(spi->dev.of_node, "duty-cycle", &dc);
if (ret)
dc = 50;
/* ir_spi_set_duty_cycle cannot fail,
* it returns int to be compatible with the
* rc->s_tx_duty_cycle function
*/
ir_spi_set_duty_cycle(idata->rc, dc);
idata->freq = IR_SPI_DEFAULT_FREQUENCY;
return devm_rc_register_device(&spi->dev, idata->rc);
}
static int ir_spi_remove(struct spi_device *spi)
{
return 0;
}
static const struct of_device_id ir_spi_of_match[] = {
{ .compatible = "ir-spi-led" },
{},
};
static struct spi_driver ir_spi_driver = {
.probe = ir_spi_probe,
.remove = ir_spi_remove,
.driver = {
.name = IR_SPI_DRIVER_NAME,
.of_match_table = ir_spi_of_match,
},
};
module_spi_driver(ir_spi_driver);
MODULE_AUTHOR("Andi Shyti <andi.shyti@samsung.com>");
MODULE_DESCRIPTION("SPI IR LED");
MODULE_LICENSE("GPL v2");
|
