paulbsd/pinephone-keyboard
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Drop I2C bit functions, to make timing easier to modify

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I2C to the charger now has clean 100kHz timing. One read command now takes
400us, and one write command takes 300us to execute.
This commit is contained in:
Ondrej Jirman 2021-09-05 02:26:55 +02:00
parent 78c72fe448
commit 31c41b7d9e
2 changed files with 53 additions and 43 deletions
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92
firmware/main.c
View File

@ -1006,7 +1006,7 @@ static __bit poll_scl_busy(void)
} }
*/ */
void i2c_start_condition(void) static void i2c_start_condition(void)
{ {
CHG_RELEASE_SDA; CHG_RELEASE_SDA;
delay_us(5); delay_us(5);
@ -1021,7 +1021,7 @@ void i2c_start_condition(void)
delay_us(5); delay_us(5);
} }
void i2c_stop_condition(void) static void i2c_stop_condition(void)
{ {
CHG_PULL_SDA; CHG_PULL_SDA;
delay_us(5); delay_us(5);
@ -1033,68 +1033,78 @@ void i2c_stop_condition(void)
delay_us(5); delay_us(5);
} }
void i2c_write_bit(__bit b) static __bit i2c_write_byte(uint8_t data)
{ {
if (b) uint8_t i;
CHG_RELEASE_SDA; __bit ack = 1;
else
CHG_PULL_SDA; // write data
for (i = 0; i < 8; i++) {
// write the most-significant bit
if (data & 0x80)
CHG_RELEASE_SDA;
else
CHG_PULL_SDA;
delay_us(1);
CHG_RELEASE_SCL;
delay_us(5);
CHG_PULL_SCL;
delay_us(1);
data <<= 1;
}
delay_us(1); delay_us(1);
CHG_RELEASE_SCL; // read ack bit
delay_us(5);
CHG_PULL_SCL;
delay_us(1);
}
__bit i2c_read_bit(void)
{
__bit b;
CHG_RELEASE_SDA; CHG_RELEASE_SDA;
CHG_RELEASE_SCL; CHG_RELEASE_SCL;
delay_us(4); delay_us(3);
if (CHG_PORT & CHG_SDA) if (CHG_PORT & CHG_SDA)
b = 1; ack = 0;
else
b = 0;
CHG_PULL_SCL; CHG_PULL_SCL;
delay_us(2); delay_us(2);
return b; return ack;
} }
__bit i2c_write_byte(uint8_t data) static uint8_t i2c_read_byte(__bit ack)
{
uint8_t i;
// write data
for (i = 0; i < 8; i++) {
i2c_write_bit(data & 0x80); // write the most-significant bit
data <<= 1;
}
// read ack bit
return !i2c_read_bit();
}
uint8_t i2c_read_byte(__bit ack)
{ {
uint8_t data = 0; uint8_t data = 0;
uint8_t i; uint8_t i;
CHG_RELEASE_SDA;
// read data // read data
for (i = 0; i < 8; i++) { for (i = 0; i < 8; i++) {
data <<= 1; data <<= 1;
data |= i2c_read_bit();
CHG_RELEASE_SCL;
delay_us(4);
if (CHG_PORT & CHG_SDA)
data |= 1;
CHG_PULL_SCL;
delay_us(2);
} }
// send ack // send ack
i2c_write_bit(!ack); if (ack)
CHG_PULL_SDA;
else
CHG_RELEASE_SDA;
delay_us(1);
CHG_RELEASE_SCL;
delay_us(5);
CHG_PULL_SCL;
delay_us(1);
return data; return data;
} }

4
i2c-charger-ctl.c
View File

@ -130,7 +130,7 @@ uint8_t read_power(int fd, uint8_t reg)
syscall_error(ret < 0, "I2C_RDWR failed"); syscall_error(ret < 0, "I2C_RDWR failed");
for (int i = 0; i < 5; i++) { for (int i = 0; i < 5; i++) {
usleep(2000); usleep(700);
// read the result // read the result
uint8_t buf2[1] = { REG_SYS_CHG_DATA, }; uint8_t buf2[1] = { REG_SYS_CHG_DATA, };
@ -183,7 +183,7 @@ void write_power(int fd, uint8_t reg, uint8_t val)
syscall_error(ret < 0, "I2C_RDWR failed"); syscall_error(ret < 0, "I2C_RDWR failed");
for (int i = 0; i < 5; i++) { for (int i = 0; i < 5; i++) {
usleep(2000); usleep(700);
// read the result // read the result
uint8_t buf2[1] = { REG_SYS_COMMAND, }; uint8_t buf2[1] = { REG_SYS_COMMAND, };