drvgfaspi/drvmain.c

#include <linux/init.h>
#include <linux/kernel.h>    // printk()
#include <linux/kobject.h>   // struct kobject
#include <linux/errno.h>     // error codes
#include <linux/module.h>    // THIS_MODULE
#include <linux/sysfs.h>
#include <linux/syscalls.h>
#include <asm/ioctls.h>
#include <linux/spi/spidev.h>
#include "kfile.h"

/////////////////////////////////////////////////////////////////////////////

MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("GfA");

/////////////////////////////////////////////////////////////////////////////

#define _SPI_DEVICE				"/dev/spidev1.0"
static struct file *g_fdSpiDev	= NULL;

/////////////////////////////////////////////////////////////////////////////

static int temp = 0;
static struct kobject *pKoGfa = NULL, *pKoTiva = NULL;

/////////////////////////////////////////////////////////////////////////////

static ssize_t tivaTempShow(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
{
	printk(KERN_ALERT "tivaTemp - Read!!!\n");
	return sprintf(buf, "%d", ++temp);
}

static ssize_t tivaTempStore(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count)
{
	printk(KERN_ALERT "tivaTemp - Write!!!\n");
	sscanf(buf, "%d", &temp);
	return count;
}

/////////////////////////////////////////////////////////////////////////////

static struct kobj_attribute tivaTempAtt = __ATTR(temp, 0660, tivaTempShow, tivaTempStore);

/////////////////////////////////////////////////////////////////////////////

static int drv_init(void)
{
	long ret;
	uint8_t mode = SPI_MODE_3;
	uint8_t bits = 8;
	uint32_t speed = 1000000;

	/////////////////////////////////////////////////////////////////////////

	do
	{
		if(!(pKoGfa = kobject_create_and_add("gfa", /*kernel_kobj*/NULL)))
		{
			printk(KERN_ALERT "kobject_create_and_add failed\n");
			break;
		}

		if(!(pKoTiva = kobject_create_and_add("tiva", pKoGfa)))
		{
			printk(KERN_ALERT "kobject_create_and_add failed\n");
			break;
		}

		/////////////////////////////////////////////////////////////////////

		if(sysfs_create_file(pKoTiva, &tivaTempAtt.attr))
		{
			printk(KERN_ALERT "sysfs_create_file failed\n");
			break;
		}

		/////////////////////////////////////////////////////////////////////

		if(!(g_fdSpiDev = kf_open(_SPI_DEVICE, O_RDWR, 0)))
		{
			printk(KERN_ALERT "file_open failed\n");
			break;
		}

		/////////////////////////////////////////////////////////////////////

		ret = kf_ioctl(g_fdSpiDev, SPI_IOC_WR_MODE, (unsigned long)&mode);
		if(ret < 0)
		{
			printk(KERN_ALERT "can't set spi mode\n");
			break;
		}

		mode = 0;
		ret = kf_ioctl(g_fdSpiDev, SPI_IOC_RD_MODE, (unsigned long)&mode);
		if(ret < 0)
		{
			printk(KERN_ALERT "can't get spi mode\n");
			break;
		}

		ret = kf_ioctl(g_fdSpiDev, SPI_IOC_WR_BITS_PER_WORD, (unsigned long)&bits);
		if(ret < 0)
		{
			printk(KERN_ALERT "can't set bits per word\n");
			break;
		}

		bits = 0;
		ret = kf_ioctl(g_fdSpiDev, SPI_IOC_RD_BITS_PER_WORD, (unsigned long)&bits);
		if(ret < 0)
		{
			printk(KERN_ALERT "can't get bits per word\n");
			break;
		}

		ret = kf_ioctl(g_fdSpiDev, SPI_IOC_WR_MAX_SPEED_HZ, (unsigned long)&speed);
		if(ret < 0)
		{
			printk(KERN_ALERT "can't set max speed hz\n");
			break;
		}

		speed = 0;
		ret = kf_ioctl(g_fdSpiDev, SPI_IOC_RD_MAX_SPEED_HZ, (unsigned long)&speed);
		if(ret < 0)
		{
			printk(KERN_ALERT "can't get max speed hz\n");
			break;
		}

		/////////////////////////////////////////////////////////////////////

		printk(KERN_ALERT "mode:  %hhu\n", mode);
		printk(KERN_ALERT "bits:  %hhu\n", bits);
		printk(KERN_ALERT "speed: %u\n", speed);
		printk(KERN_ALERT "%s\n", __FUNCTION__);
		return 0;
	}
	while(0);

	/////////////////////////////////////////////////////////////////////////

	if(g_fdSpiDev)
		kf_close(g_fdSpiDev);

	if(pKoTiva)
	{
		sysfs_remove_file(pKoTiva, &tivaTempAtt.attr);
		kobject_put(pKoTiva);
		pKoTiva = NULL;
	}

	if(pKoGfa)
	{
		kobject_put(pKoGfa);
		pKoGfa = NULL;
	}

	return -ENOMEM;
}

/////////////////////////////////////////////////////////////////////////////

static void drv_exit(void)
{
	if(g_fdSpiDev)
		kf_close(g_fdSpiDev);

	if(pKoTiva)
	{
		sysfs_remove_file(pKoTiva, &tivaTempAtt.attr);
		kobject_put(pKoTiva);
	}

	if(pKoGfa)
		kobject_put(pKoGfa);

	printk(KERN_ALERT "%s\n", __FUNCTION__);
}

/////////////////////////////////////////////////////////////////////////////

module_init(drv_init);
module_exit(drv_exit);