int32_t w1_read_temp(struct w1_dev *dev, unsigned long flags)
{
static uint8_t scratchpad[8];
int class = w1_class(dev);
int32_t res;
int16_t cval;
int i;
/* The caller is expected to have checked the class. but still... */
switch(class) {
case 0x10: case 0x28: case 0x42:
break; /* Supported, at least for temperature input */
default:
return 1l<<31; /* very negative */
}
/* If so asked, jump over start-conversion and only collect result */
if (flags & W1_FLAG_COLLECT)
goto collect;
w1_match_rom(dev);
w1_write_byte(dev->bus, W1_CMDT_CONVERT);
/* If so asked, don't wait for the conversion to be over */
if (flags & W1_FLAG_NOWAIT)
return 0;
while(bathos_w1_ops.read_bit(dev->bus) == 0)
;
collect:
w1_match_rom(dev);
w1_write_byte(dev->bus, W1_CMDT_R_SPAD);
for (i = 0; i < sizeof(scratchpad); i++)
scratchpad[i] = w1_read_byte(dev->bus);
res = 0;
cval = scratchpad[1] << 8 | scratchpad[0];
switch(class) {
case 0x10:
/* 18S20: two bytes plus "count remain" value */
res = (int32_t)cval << 15; /* 1 decimal points */
res -= 0x4000; /* - 0.25 degrees */
res |= scratchpad[6] << 12; /* 1/16th of degree each */
break;
case 0x28:
case 0x42:
/* 18B20 and DS28EA00: only the two bytes */
res = (int32_t)cval << 12; /* 4 decimal points */
break;
}
return res;
}
static int ds24xxx_read_buf(struct udevice *dev, unsigned int offset,
u8 *buf, unsigned int count)
{
w1_reset_select(dev);
w1_write_byte(dev, W1_F2D_READ_EEPROM);
w1_write_byte(dev, offset & 0xff);
w1_write_byte(dev, offset >> 8);
return w1_read_buf(dev, buf, count);
}
int w1_read_eeprom(struct w1_dev *dev, int offset, uint8_t *buffer, int blen)
{
int i;
w1_match_rom(dev);
w1_write_byte(dev->bus, W1_CMDR_R_MEMORY);
/* read of target addr */
w1_write_byte(dev->bus, LSB_ADDR(offset));
w1_write_byte(dev->bus, MSB_ADDR(offset));
for (i = 0; i < blen; i++)
buffer[i] = w1_read_byte(dev->bus);
return 0;
}
static int ds18b20_read_temp(float* temp, int mask) {
int res = 0;
//start conversion
PIOB_ODR = mask; //disable output
ds18b20_reset(mask);
w1_write_byte(mask, DS18B20_SKIP_ROM);
w1_write_byte(mask, DS18B20_CONVERT_T);
res = usleep(750000);
//reading
ds18b20_reset(mask);
w1_write_byte(mask, DS18B20_SKIP_ROM);
w1_write_byte(mask, DS18B20_READ_SCRATCHPAD);
*temp = (w1_read_byte(mask) | (w1_read_byte(mask) << 8));
(*temp) /= 16;
//skip reading the rest of scratchpad bytes
PIOB_OER = mask; //enable output
PIOB_CODR = mask; //level low
return res;
}
int w1_write_eeprom(struct w1_dev *dev, int offset, const uint8_t *buffer,
int blen)
{
int i;
int read_data;
w1_match_rom(dev);
w1_write_byte(dev->bus, W1_CMDR_W_SPAD);
/* write of target addr */
w1_write_byte(dev->bus, LSB_ADDR(offset));
w1_write_byte(dev->bus, MSB_ADDR(offset));
/* write to scratchpad */
for (i = 0; i < blen; i++)
w1_write_byte(dev->bus, buffer[i]);
for (; i < 32; i++)
w1_write_byte(dev->bus, '\0'); /*padding */
w1_match_rom(dev);
w1_write_byte(dev->bus, W1_CMDR_C_SPAD);
/* copy to memory */
w1_write_byte(dev->bus, LSB_ADDR(offset));
w1_write_byte(dev->bus, MSB_ADDR(offset));
/* ending offset/data status byte */
w1_write_byte(dev->bus, 0x1f);
usleep(10000);
/* check final status byte */
read_data = w1_read_byte(dev->bus);
if (read_data != 0xaa)
return -1;
return 0;
}
