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/*
Special pin usage:
U8G_PI_I2C_OPTION additional options
U8G_PI_A0_STATE used to store the last value of the command/data register selection
U8G_PI_SET_A0 1: Signal request to update I2C device with new A0_STATE, 0: Do nothing, A0_STATE matches I2C device
U8G_PI_SCL clock line (NOT USED)
U8G_PI_SDA data line (NOT USED)
U8G_PI_RESET reset line (currently disabled, see below)
Protocol:
SLA, Cmd/Data Selection, Arguments
The command/data register is selected by a special instruction byte, which is sent after SLA
The continue bit is always 0 so that a (re)start is equired for the change from cmd to/data mode
*/
#include "u8g.h"
#if defined(U8G_RASPBERRY_PI)
#include <wiringPi.h>
#include <wiringPiI2C.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#define I2C_SLA 0x3c
#define I2C_CMD_MODE 0x000
#define I2C_DATA_MODE 0x040
#if defined(U8G_WITH_PINLIST)
uint8_t u8g_com_raspberrypi_ssd_start_sequence(u8g_t *u8g)
{
/* are we requested to set the a0 state? */
if ( u8g->pin_list[U8G_PI_SET_A0] == 0 )
return 1;
/* setup bus, might be a repeated start */
if ( u8g_i2c_start(I2C_SLA) == 0 )
return 0;
if ( u8g->pin_list[U8G_PI_A0_STATE] == 0 )
{
if ( u8g_i2c_send_mode(I2C_CMD_MODE) == 0 )
return 0;
}
else
{
if ( u8g_i2c_send_mode(I2C_DATA_MODE) == 0 )
return 0;
}
u8g->pin_list[U8G_PI_SET_A0] = 0;
return 1;
}
uint8_t u8g_com_raspberrypi_ssd_i2c_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr)
{
switch(msg)
{
case U8G_COM_MSG_INIT:
u8g_i2c_init(u8g->pin_list[U8G_PI_I2C_OPTION]);
u8g_SetPIOutput(u8g, U8G_PI_RESET);
u8g_SetPIOutput(u8g, U8G_PI_A0);
break;
case U8G_COM_MSG_STOP:
break;
case U8G_COM_MSG_RESET:
break;
case U8G_COM_MSG_CHIP_SELECT:
u8g->pin_list[U8G_PI_A0_STATE] = 0;
u8g->pin_list[U8G_PI_SET_A0] = 1; /* force a0 to set again, also forces start condition */
if ( arg_val == 0 )
{
/* disable chip, send stop condition */
u8g_i2c_stop();
}
else
{
/* enable, do nothing: any byte writing will trigger the i2c start */
}
break;
case U8G_COM_MSG_WRITE_BYTE:
//u8g->pin_list[U8G_PI_SET_A0] = 1;
if ( u8g_com_raspberrypi_ssd_start_sequence(u8g) == 0 )
return u8g_i2c_stop(), 0;
if ( u8g_i2c_send_byte(arg_val) == 0 )
return u8g_i2c_stop(), 0;
// u8g_i2c_stop();
break;
case U8G_COM_MSG_WRITE_SEQ:
//u8g->pin_list[U8G_PI_SET_A0] = 1;
if ( u8g_com_raspberrypi_ssd_start_sequence(u8g) == 0 )
return u8g_i2c_stop(), 0;
{
register uint8_t *ptr = (uint8_t *)arg_ptr;
while( arg_val > 0 )
{
if ( u8g_i2c_send_byte(*ptr++) == 0 )
return u8g_i2c_stop(), 0;
arg_val--;
}
}
// u8g_i2c_stop();
break;
case U8G_COM_MSG_WRITE_SEQ_P:
//u8g->pin_list[U8G_PI_SET_A0] = 1;
if ( u8g_com_raspberrypi_ssd_start_sequence(u8g) == 0 )
return u8g_i2c_stop(), 0;
{
register uint8_t *ptr = (uint8_t *)arg_ptr;
while( arg_val > 0 )
{
if ( u8g_i2c_send_byte(u8g_pgm_read(ptr)) == 0 )
return 0;
ptr++;
arg_val--;
}
}
// u8g_i2c_stop();
break;
case U8G_COM_MSG_ADDRESS: /* define cmd (arg_val = 0) or data mode (arg_val = 1) */
u8g->pin_list[U8G_PI_A0_STATE] = arg_val;
u8g->pin_list[U8G_PI_SET_A0] = 1; /* force a0 to set again */
#ifdef OLD_CODE
if ( i2c_state != 0 )
{
u8g_i2c_stop();
i2c_state = 0;
}
if ( u8g_com_raspberrypi_ssd_start_sequence(arg_val) == 0 )
return 0;
/* setup bus, might be a repeated start */
/*
if ( u8g_i2c_start(I2C_SLA) == 0 )
return 0;
if ( arg_val == 0 )
{
i2c_state = 1;
if ( u8g_i2c_send_byte(I2C_CMD_MODE) == 0 )
return 0;
}
else
{
i2c_state = 2;
if ( u8g_i2c_send_byte(I2C_DATA_MODE) == 0 )
return 0;
}
*/
#endif
break;
}
return 1;
}
#else /* defined(U8G_WITH_PINLIST) */
uint8_t u8g_com_raspberrypi_ssd_i2c_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr) {
return 1;
}
#endif /* defined(U8G_WITH_PINLIST) */
#endif
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