180 lines
3.9 KiB
C
180 lines
3.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
// SPI driven IR LED device driver
|
|
//
|
|
// Copyright (c) 2016 Samsung Electronics Co., Ltd.
|
|
// Copyright (c) Andi Shyti <andi@etezian.org>
|
|
|
|
#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" },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, ir_spi_of_match);
|
|
|
|
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@etezian.org>");
|
|
MODULE_DESCRIPTION("SPI IR LED");
|
|
MODULE_LICENSE("GPL v2");
|