/* * Simple synchronous userspace interface to SPI devices * * Copyright (C) 2006 SWAPP * Andrea Paterniani <a.paterniani@swapp-eng.it> * Copyright (C) 2007 David Brownell (simplification, cleanup) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/init.h> #include <linux/module.h> #include <linux/ioctl.h> #include <linux/fs.h> #include <linux/device.h> #include <linux/err.h> #include <linux/list.h> #include <linux/errno.h> #include <linux/mutex.h> #include <linux/slab.h> #include <linux/compat.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/acpi.h> #include <linux/spi/spi.h> #include <linux/spi/spidev.h> #include <linux/uaccess.h> #include <linux/gpio/consumer.h> #define OLED_IOC_INIT 123 #define OLED_IOC_SET_POS 124 //为0 表示命令，为1表示数据 #define OLED_CMD 0 #define OLED_DATA 1 /*-------------------------------------------------------------------------*/ static struct spi_device *oled; static int major; static struct gpio_desc *dc_gpio; static void dc_pin_init(void) { gpiod_direction_output(dc_gpio, 1); } static void oled_set_dc_pin(int val) { gpiod_set_value(dc_gpio, val); } static void spi_write_datas(const unsigned char *buf, int len) { spi_write(oled, buf, len); } /********************************************************************** * 函数名称： oled_write_cmd * 功能描述： oled向特定地址写入数据或者命令 * 输入参数：@uc_data :要写入的数据 @uc_cmd:为1则表示写入数据，为0表示写入命令 * 输出参数：无 * 返 回 值： 无 * 修改日期 版本号 修改人 修改内容 * ----------------------------------------------- * 2020/03/04 V1.0 芯晓 创建 ***********************************************************************/ static void oled_write_cmd_data(unsigned char uc_data,unsigned char uc_cmd) { if(uc_cmd==0) { oled_set_dc_pin(0); } else { oled_set_dc_pin(1);//拉高，表示写入数据 } spi_write_datas(&uc_data, 1);//写入 } /********************************************************************** * 函数名称： oled_init * 功能描述： oled_init的初始化，包括SPI控制器得初始化 * 输入参数：无 * 输出参数： 初始化的结果 * 返 回 值： 成功则返回0，否则返回-1 * 修改日期 版本号 修改人 修改内容 * ----------------------------------------------- * 2020/03/15 V1.0 芯晓 创建 ***********************************************************************/ static int oled_init(void) { oled_write_cmd_data(0xae,OLED_CMD);//关闭显示 oled_write_cmd_data(0x00,OLED_CMD);//设置 lower column address oled_write_cmd_data(0x10,OLED_CMD);//设置 higher column address oled_write_cmd_data(0x40,OLED_CMD);//设置 display start line oled_write_cmd_data(0xB0,OLED_CMD);//设置page address oled_write_cmd_data(0x81,OLED_CMD);// contract control oled_write_cmd_data(0x66,OLED_CMD);//128 oled_write_cmd_data(0xa1,OLED_CMD);//设置 segment remap oled_write_cmd_data(0xa6,OLED_CMD);//normal /reverse oled_write_cmd_data(0xa8,OLED_CMD);//multiple ratio oled_write_cmd_data(0x3f,OLED_CMD);//duty = 1/64 oled_write_cmd_data(0xc8,OLED_CMD);//com scan direction oled_write_cmd_data(0xd3,OLED_CMD);//set displat offset oled_write_cmd_data(0x00,OLED_CMD);// oled_write_cmd_data(0xd5,OLED_CMD);//set osc division oled_write_cmd_data(0x80,OLED_CMD);// oled_write_cmd_data(0xd9,OLED_CMD);//ser pre-charge period oled_write_cmd_data(0x1f,OLED_CMD);// oled_write_cmd_data(0xda,OLED_CMD);//set com pins oled_write_cmd_data(0x12,OLED_CMD);// oled_write_cmd_data(0xdb,OLED_CMD);//set vcomh oled_write_cmd_data(0x30,OLED_CMD);// oled_write_cmd_data(0x8d,OLED_CMD);//set charge pump disable oled_write_cmd_data(0x14,OLED_CMD);// oled_write_cmd_data(0xaf,OLED_CMD);//set dispkay on return 0; } //坐标设置 /********************************************************************** * 函数名称： OLED_DIsp_Set_Pos * 功能描述：设置要显示的位置 * 输入参数：@ x ：要显示的column address @y :要显示的page address * 输出参数： 无 * 返 回 值： * 修改日期 版本号 修改人 修改内容 * ----------------------------------------------- * 2020/03/15 V1.0 芯晓 创建 ***********************************************************************/ static void OLED_DIsp_Set_Pos(int x, int y) { oled_write_cmd_data(0xb0+y,OLED_CMD); oled_write_cmd_data((x&0x0f),OLED_CMD); oled_write_cmd_data(((x&0xf0)>>4)|0x10,OLED_CMD); } static long spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { int x, y; /* 根据cmd操作硬件 */ switch (cmd) { case OLED_IOC_INIT: /* init */ { dc_pin_init(); oled_init(); break; } case OLED_IOC_SET_POS: /* set pos */ { x = arg & 0xff; y = (arg >> 8) & 0xff; OLED_DIsp_Set_Pos(x, y); break; } } return 0; } static ssize_t spidev_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos) { char *ker_buf; int err; ker_buf = kmalloc(count, GFP_KERNEL); err = copy_from_user(ker_buf, buf, count); oled_set_dc_pin(1);//拉高，表示写入数据 spi_write_datas(ker_buf, count); kfree(ker_buf); return count; } static const struct file_operations spidev_fops = { .owner = THIS_MODULE, /* REVISIT switch to aio primitives, so that userspace * gets more complete API coverage. It'll simplify things * too, except for the locking. */ .write = spidev_write, .unlocked_ioctl = spidev_ioctl, }; /*-------------------------------------------------------------------------*/ /* The main reason to have this class is to make mdev/udev create the * /dev/spidevB.C character device nodes exposing our userspace API. * It also simplifies memory management. */ static struct class *spidev_class; static const struct of_device_id spidev_dt_ids[] = { { .compatible = "cumtchw,oled" }, {}, }; /*-------------------------------------------------------------------------*/ static int spidev_probe(struct spi_device *spi) { /* 1. 记录spi_device */ oled = spi; /* 2. 注册字符设备 */ major = register_chrdev(0, "cumtchw_oled", &spidev_fops); spidev_class = class_create(THIS_MODULE, "cumtchw_oled"); device_create(spidev_class, NULL, MKDEV(major, 0), NULL, "cumtchw_oled"); /* 3. 获得GPIO引脚 */ dc_gpio = gpiod_get(&spi->dev, "dc", 0); return 0; } static int spidev_remove(struct spi_device *spi) { gpiod_put(dc_gpio); /* 反注册字符设备 */ device_destroy(spidev_class, MKDEV(major, 0)); class_destroy(spidev_class); unregister_chrdev(major, "cumtchw_oled"); return 0; } static struct spi_driver spidev_spi_driver = { .driver = { .name = "cumtchw_spi_oled_drv", .of_match_table = of_match_ptr(spidev_dt_ids), }, .probe = spidev_probe, .remove = spidev_remove, /* NOTE: suspend/resume methods are not necessary here. * We don't do anything except pass the requests to/from * the underlying controller. The refrigerator handles * most issues; the controller driver handles the rest. */ }; /*-------------------------------------------------------------------------*/ static int __init spidev_init(void) { int status; status = spi_register_driver(&spidev_spi_driver); if (status < 0) { } return status; } module_init(spidev_init); static void __exit spidev_exit(void) { spi_unregister_driver(&spidev_spi_driver); } module_exit(spidev_exit); MODULE_LICENSE("GPL"); * 设备树配置 ```c &ecspi1 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_ecspi1>; fsl,spi-num-chipselects = <2>; cs-gpios = <&gpio4 26 GPIO_ACTIVE_LOW>, <&gpio4 24 GPIO_ACTIVE_LOW>; status = "okay"; oled: oled { compatible = "cumtchw,oled"; reg = <0>; spi-max-frequency = <10000000>; dc-gpios = <&gpio4 20 GPIO_ACTIVE_HIGH>; }; };
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