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Code Issues Releases Activity

issue #593, avr opt for i2c (disabled by default!)

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This commit is contained in:
kraus
2018-04-29 15:13:52 +02:00
parent 6502205871
commit 4141c9483a
5 changed files with 406 additions and 172 deletions
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cppsrc/U8x8lib.cpp
+221
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@@ -552,6 +552,227 @@ extern "C" uint8_t u8x8_byte_arduino_2nd_hw_spi(U8X8_UNUSED u8x8_t *u8x8, U8X8_U
return 1;
}
/*=============================================*/
/* fast SW I2C for AVR uC */
#if !defined(U8X8_USE_PINS)
/* no pin information (very strange), so fallback */
extern "C" uint8_t u8x8_byte_arduino_sw_i2c(U8X8_UNUSED u8x8_t *u8x8, U8X8_UNUSED uint8_t msg, U8X8_UNUSED uint8_t arg_int, U8X8_UNUSED void *arg_ptr)
{
return u8x8_byte_sw_i2c(u8x8, msg,arg_int, arg_ptr);
}
#elif !defined(U8X8_USE_ARDUINO_AVR_SW_I2C_OPTIMIZATION)
extern "C" uint8_t u8x8_byte_arduino_sw_i2c(U8X8_UNUSED u8x8_t *u8x8, U8X8_UNUSED uint8_t msg, U8X8_UNUSED uint8_t arg_int, U8X8_UNUSED void *arg_ptr)
{
return u8x8_byte_sw_i2c(u8x8, msg,arg_int, arg_ptr);
}
#elif __AVR_ARCH__ == 4 || __AVR_ARCH__ == 5 || __AVR_ARCH__ == 51 || __AVR_ARCH__ == 6
/* the following static vars are recalculated in U8X8_MSG_BYTE_START_TRANSFER */
/* so, it should be possible to use multiple displays with different pins */
static volatile uint8_t *arduino_i2c_clock_port;
static uint8_t arduino_i2c_clock_mask;
static uint8_t arduino_i2c_clock_n_mask;
static volatile uint8_t *arduino_i2c_data_port;
static uint8_t arduino_i2c_data_mask;
static uint8_t arduino_i2c_data_n_mask;
/*
software i2c,
ignores ACK response (which is anyway not provided by some displays)
also does not allow reading from the device
*/
static void i2c_delay(u8x8_t *u8x8) U8X8_NOINLINE;
static void i2c_delay(u8x8_t *u8x8)
{
//u8x8_gpio_Delay(u8x8, U8X8_MSG_DELAY_10MICRO, u8x8->display_info->i2c_bus_clock_100kHz);
u8x8_gpio_Delay(u8x8, U8X8_MSG_DELAY_I2C, u8x8->display_info->i2c_bus_clock_100kHz);
}
static void i2c_init(u8x8_t *u8x8)
{
*arduino_i2c_clock_port |= arduino_i2c_clock_mask;
*arduino_i2c_data_port |= arduino_i2c_data_mask;
i2c_delay(u8x8);
}
/* actually, the scl line is not observed, so this procedure does not return a value */
static void i2c_read_scl_and_delay(u8x8_t *u8x8)
{
/* set as input (line will be high) */
*arduino_i2c_clock_port |= arduino_i2c_clock_mask;
i2c_delay(u8x8);
}
static void i2c_clear_scl(u8x8_t *u8x8)
{
*arduino_i2c_clock_port &= arduino_i2c_clock_n_mask;
}
static void i2c_read_sda(u8x8_t *u8x8)
{
/* set as input (line will be high) */
*arduino_i2c_data_port |= arduino_i2c_data_mask;
}
static void i2c_clear_sda(u8x8_t *u8x8)
{
/* set open collector and drive low */
*arduino_i2c_data_port &= arduino_i2c_data_n_mask;
}
static void i2c_start(u8x8_t *u8x8)
{
if ( u8x8->i2c_started != 0 )
{
/* if already started: do restart */
i2c_read_sda(u8x8); /* SDA = 1 */
i2c_delay(u8x8);
i2c_read_scl_and_delay(u8x8);
}
i2c_read_sda(u8x8);
/* send the start condition, both lines go from 1 to 0 */
i2c_clear_sda(u8x8);
i2c_delay(u8x8);
i2c_clear_scl(u8x8);
u8x8->i2c_started = 1;
}
static void i2c_stop(u8x8_t *u8x8)
{
/* set SDA to 0 */
i2c_clear_sda(u8x8);
i2c_delay(u8x8);
/* now release all lines */
i2c_read_scl_and_delay(u8x8);
/* set SDA to 1 */
i2c_read_sda(u8x8);
i2c_delay(u8x8);
u8x8->i2c_started = 0;
}
static void i2c_write_bit(u8x8_t *u8x8, uint8_t val)
{
if (val)
i2c_read_sda(u8x8);
else
i2c_clear_sda(u8x8);
i2c_delay(u8x8);
i2c_read_scl_and_delay(u8x8);
i2c_clear_scl(u8x8);
}
static void i2c_read_bit(u8x8_t *u8x8)
{
//uint8_t val;
/* do not drive SDA */
i2c_read_sda(u8x8);
i2c_delay(u8x8);
i2c_read_scl_and_delay(u8x8);
i2c_read_sda(u8x8);
i2c_delay(u8x8);
i2c_clear_scl(u8x8);
//return val;
}
static void i2c_write_byte(u8x8_t *u8x8, uint8_t b)
{
i2c_write_bit(u8x8, b & 128);
i2c_write_bit(u8x8, b & 64);
i2c_write_bit(u8x8, b & 32);
i2c_write_bit(u8x8, b & 16);
i2c_write_bit(u8x8, b & 8);
i2c_write_bit(u8x8, b & 4);
i2c_write_bit(u8x8, b & 2);
i2c_write_bit(u8x8, b & 1);
/* read ack from client */
/* 0: ack was given by client */
/* 1: nothing happend during ack cycle */
i2c_read_bit(u8x8);
}
extern "C" uint8_t u8x8_byte_arduino_sw_i2c(U8X8_UNUSED u8x8_t *u8x8, U8X8_UNUSED uint8_t msg, U8X8_UNUSED uint8_t arg_int, U8X8_UNUSED void *arg_ptr)
{
uint8_t *data;
switch(msg)
{
case U8X8_MSG_BYTE_SEND:
data = (uint8_t *)arg_ptr;
while( arg_int > 0 )
{
i2c_write_byte(u8x8, *data);
data++;
arg_int--;
}
break;
case U8X8_MSG_BYTE_INIT:
pinMode(u8x8->pins[U8X8_PIN_I2C_CLOCK], OUTPUT);
digitalWrite(u8x8->pins[U8X8_PIN_I2C_CLOCK], 1);
pinMode(u8x8->pins[U8X8_PIN_I2C_DATA], OUTPUT);
digitalWrite(u8x8->pins[U8X8_PIN_I2C_DATA], 1);
i2c_init(u8x8);
break;
case U8X8_MSG_BYTE_SET_DC:
break;
case U8X8_MSG_BYTE_START_TRANSFER:
/* there is no consistency checking for u8x8->pins[U8X8_PIN_I2C_CLOCK] */
arduino_i2c_clock_port = portOutputRegister(digitalPinToPort(u8x8->pins[U8X8_PIN_I2C_CLOCK]));
arduino_i2c_clock_mask = digitalPinToBitMask(u8x8->pins[U8X8_PIN_I2C_CLOCK]);
arduino_i2c_clock_n_mask = ~arduino_i2c_clock_mask;
/* there is no consistency checking for u8x8->pins[U8X8_PIN_I2C_DATA] */
arduino_i2c_data_port = portOutputRegister(digitalPinToPort(u8x8->pins[U8X8_PIN_I2C_DATA]));
arduino_i2c_data_mask = digitalPinToBitMask(u8x8->pins[U8X8_PIN_I2C_DATA]);
arduino_i2c_data_n_mask = ~arduino_i2c_data_mask;
i2c_start(u8x8);
i2c_write_byte(u8x8, u8x8_GetI2CAddress(u8x8));
break;
case U8X8_MSG_BYTE_END_TRANSFER:
i2c_stop(u8x8);
break;
default:
return 0;
}
return 1;
}
#else
/* not AVR architecture, fallback */
extern "C" uint8_t u8x8_byte_arduino_sw_i2c(U8X8_UNUSED u8x8_t *u8x8, U8X8_UNUSED uint8_t msg, U8X8_UNUSED uint8_t arg_int, U8X8_UNUSED void *arg_ptr)
{
return u8x8_byte_sw_i2c(u8x8, msg,arg_int, arg_ptr);
}
#endif
/*=============================================*/