/*
 * Copyright (c) 2014  Sulev-Madis Silber <ketas@si.pri.ee>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *
 * ORIGINAL CODE:
 *
 * bbb_sysutil.c  Beaglebone Black System Utility
 *
 * Compile with:
 *     cc bbb_sysutil.c -o bbb_sysutil
 *
 * Winston Smith <smith.winston.101@gmail.com>
 */


#include <sys/cdefs.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <unistd.h>
#include <dev/iicbus/iic.h>


#define MIN(a,b) ((a) < (b) ? (a) : (b))


/*
 * BeagleBone Black system EEPROM signature
 */

uint8_t signature[] = { 0xAA, 0x55, 0x33, 0xEE };


typedef struct
{
	int   value;
	char *name;
}
KV;

static KV TPS65217_ID[] =
{
	{ 0b01100000, "TPS65217D" },
	{ 0b01110000, "TPS65217A" },
	{ 0b11100000, "TPS65217C" },
	{ 0b11110000, "TPS65217B" },
	{ 0, 0 },
};

static KV TPS65217_STATUS[] =
{
	{ 0b1000, "ACPWR"  },
	{ 0b0100, "USBPWR" },
	{ 0, 0 },
};


size_t KV_lookup_value(int val, KV *table, char *buffer, size_t max)
{
	int i;
	
	
	for (i = 0; table[i].name; i++)
	{
		if (val == table[i].value)
		{
			size_t sz = MIN(max-1, strlen(table[i].name));
			strncpy(buffer, table[i].name, sz);
			buffer[sz] = 0;
			
			return sz;
		}
	}
	
	
	return 0;
}


size_t KV_lookup_mask(int mask, KV *table, char *buffer, size_t max)
{
	int    i;
	size_t used = 0;
	
	
	buffer[0] = 0;
	
	for (i = 0; table[i].name; i++)
	{
		if ((mask & table[i].value) != 0)
		{
			size_t sz = MIN(max - used - 1, strlen(table[i].name) + (used > 0 ? 1 : 0));
			
			if ((used > 0) && (sz > 0))
			{
				strcat(buffer, "|");
				used++;
				sz--;
			}
			
			strncat(buffer, table[i].name, sz);
			
			used += sz;
		}
	}
	
	
	return used;
}


/*
 * Read data from an i2c device
 */

int i2c_read(int fd, int slave, uint8_t *buffer, uint16_t offset, uint16_t offsetlen, uint16_t max)
{
	struct iic_msg       msg[2];
	struct iic_rdwr_data rdwr;
	
	
	slave = slave << 1;
	
	
	msg[0].slave = slave;
	msg[0].flags = IIC_M_WR;
	msg[0].len   = offsetlen;
	msg[0].buf   = (uint8_t*)&offset;
	
	msg[1].slave = slave;
	msg[1].flags = IIC_M_RD;
	msg[1].len   = max;
	msg[1].buf   = buffer;
	
	
	rdwr.nmsgs = 2;
	rdwr.msgs  = msg;
	
	if (ioctl(fd, I2CRDWR, &rdwr) < 0)
	{
		return errno;
	}
	
	
	return 0;
}


/*
 * Read data from the Beaglebone system EEPROM
 */

int read_eeprom(int fd)
{
	int     addr = 0x50;
	int     err;
	uint8_t buffer[28];
	char    work[32];
	
	
	// For sanity checking!
	memset((void*)buffer, '@', sizeof(buffer));
	
	if ((err = i2c_read(fd, addr, buffer, 0, sizeof(uint16_t), sizeof(buffer))) != 0)
	{
		fprintf(stderr, "ERROR: read_eeprom() (@ address %02X): i2c_read() failed with: %s (%d)\n", addr, strerror(err), err);
		return 1;
	}
	
	if (memcmp((void*)buffer, (void*)signature, sizeof(signature)) != 0)
	{
		fprintf(stderr, "ERROR: EEPROM (@ address %02X) signature mismatched (%02X:%02X:%02X:%02X)\n",
			addr,
			buffer[0], buffer[1], buffer[2], buffer[3]);
		return 1;
	}
	
	printf(" eeprom_address=%02X eeprom_signature=%02X:%02X:%02X:%02X",
		addr,
		buffer[0], buffer[1], buffer[2], buffer[3]);
	
	// Extract the 12 bytes allocated to the model
	strncpy(work, (char*)&buffer[4], 12);
	work[12] = 0;
	printf(" eeprom_model=%s", work);
	
	// Extract the 12 bytes allocated to the serial number
	strncpy(work, (char*)&buffer[16], 12);
	work[12] = 0;
	printf(" eeprom_serial=%s", work);
	
	
	return 0;
}


/*
 * Read data from the Beaglebone system PMIC
 */

int read_pmic(int fd)
{
	int     addr = 0x24;
	int     err;
	uint8_t chipid;
	uint8_t status;
	char    work[32];
	
	
	if ((err = i2c_read(fd, addr, &chipid, 0, sizeof(uint8_t), sizeof(chipid))) != 0)
	{
		fprintf(stderr, "ERROR: read_pmic() (TPS65217 PMIC @ address %02X): i2c_read() failed with: %s (%d)\n", addr, strerror(err), err);
		return 1;
	}
	
	if ((err = i2c_read(fd, addr, &status, 0x0A, sizeof(uint8_t), sizeof(status))) != 0)
	{
		fprintf(stderr, "ERROR: read_pmic() (TPS65217 PMIC @ address %02X): i2c_read() failed with: %s (%d)\n", addr, strerror(err), err);
		return 1;
	}
	
	printf(" pmic_address=%02X", addr);
	
	KV_lookup_value(chipid & 0xF0, TPS65217_ID, work, sizeof(work));
	printf(" pmic_chipid=%02X,%s-rev-1.%d", chipid, work, chipid & 0xF);
	
	KV_lookup_mask(status, TPS65217_STATUS, work, sizeof(work));
	printf(" pmic_status=%02X,%s", status, work);
	
	
	return 0;
}


int main(int argc, char **argv)
{
	int   fd  = -1;
	int   err = 0;
	char *dev = "/dev/iic0";
	char  buf[32];
	
	
	if (argc > 1)
	{
		dev = argv[1];
	}
	
	if ((fd = open(dev, O_RDWR)) < 0)
	{
		perror("open failed");
		err = 1;
		goto exit;
	}
	
	while (1)
	{
		scanf("%1s", buf);
		
		printf("i2c");
		
		read_pmic(fd);
		read_eeprom(fd);
		
		printf("\n");
		fflush(stdout);
	}
	
	exit:
		if (fd != -1)
		{
			close(fd);
		}
	
	exit(err);
}