Android下的遥控器DIY

在https://blog.youkuaiyun.com/mike8825/article/details/80955992中，介绍了几种红外方案，这里拿spi的方式来diy一个遥控器。

如果内核版本是v4.14，直接编译kernel4.14/drivers/media/rc/ir-spi.c文件，调试下，应该就可以用了。这里稍微改造了ir-spi.c，更加容易移植。

dts参考配置

记的打开平台的dma模式(在https://blog.youkuaiyun.com/mike8825/article/details/80955992已说明原因)

&spi1 {
    status = "okay";
	sprd,dma-mode = <1>;
	sprd,spi-mode = <3>;
		irled@0 {
			compatible = "ir-spi-led";
			reg = <0x0>;
			spi-max-frequency = <5000000>;
			duty-cycle = /bits/ 8 <60>;
	}; 
};

如果mos管是低电平导通，加上led-active-low;

ir-spi.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 <linux/miscdevice.h>
#include <linux/uaccess.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*4
#define	TX_IR				_IOW(0xf5, 0, int)
#define	SET_TX_CARRIER			_IOW(0xf5, 1, int)
 
struct ir_spi_data {
	u32 freq;
	bool negated;
 
	u16 tx_buf[IR_SPI_MAX_BUFSIZE];
	u16 pulse;
	u16 space;
 
	struct spi_device *spi;
	struct regulator *regulator;
};
 
struct ir_spi_data idata;
 
static int ir_spi_open(struct inode *inode, struct file *file)
{
	return 0;
}
 
static ssize_t ir_spi_tx(struct file *file,