Orange Pi5 kernel

// 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");