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cpu/samd21/periph/i2c: fix spacing, comment length

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This commit is contained in:
Ludwig Ortmann 2015-02-18 11:04:33 +01:00
parent cec87139a5
commit e9e3f3d148
1 changed files with 20 additions and 17 deletions
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37
cpu/samd21/periph/i2c.c
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@ -45,7 +45,7 @@ static inline void _stop(SercomI2cm *dev);
/**
* @brief Array holding one pre-initialized mutex for each I2C device
*/
static mutex_t locks[] = {
static mutex_t locks[] = {
#if I2C_0_EN
[I2C_0] = MUTEX_INIT,
#endif
@ -94,14 +94,14 @@ int i2c_init_master(i2c_t dev, i2c_speed_t speed)
/* DISABLE I2C MASTER */
i2c_poweroff(dev);
/*Reset I2C */
/* Reset I2C */
I2CSercom->CTRLA.reg = SERCOM_I2CS_CTRLA_SWRST;
while(I2CSercom->SYNCBUSY.reg & SERCOM_I2CM_SYNCBUSY_MASK);
/* Turn on power manager for sercom */
PM->APBCMASK.reg |= (PM_APBCMASK_SERCOM0 << (sercom_core - 20));
/*I2C using CLK GEN 0*/
/* I2C using CLK GEN 0 */
GCLK->CLKCTRL.reg = (uint32_t)(GCLK_CLKCTRL_CLKEN
| GCLK_CLKCTRL_GEN_GCLK0 << GCLK_CLKCTRL_GEN_Pos
| (sercom_core << GCLK_CLKCTRL_ID_Pos));
@ -124,13 +124,13 @@ int i2c_init_master(i2c_t dev, i2c_speed_t speed)
return -3;
}
/************ SERCOM PAD0 - SDA and SERCOM PAD1 - SCL ************/
/* DIR + INEN at one: in/out pin. DIRSET modifies DIR in order to set I2C SDA/SCL on output*/
/************ SERCOM PAD0 - SDA and SERCOM PAD1 - SCL *************/
/* DIR + INEN at one: in/out pin. DIRSET modifies DIR in order to set I2C SDA/SCL on output */
port_group->DIRSET.reg = (1 << pin_scl);
port_group->DIRSET.reg = (1 << pin_sda);
/* The Write Configuration register (WRCONFIG) requires the
* pins to to grouped into two 16-bit half-words (PIN are set up to 31)*/
* pins to to grouped into two 16-bit half-words (PIN are set up to 31) */
uint32_t lower_pin_mask = (i2c_pins & 0xFFFF);
uint32_t upper_pin_mask = (i2c_pins >> 16);
@ -161,8 +161,9 @@ int i2c_init_master(i2c_t dev, i2c_speed_t speed)
/* Enable Smart Mode (ACK is sent when DATA.DATA is read) */
I2CSercom->CTRLB.reg = SERCOM_I2CM_CTRLB_SMEN;
/* Find and set baudrate. Read speed configuration. Set transfer speed:
* SERCOM_I2CM_CTRLA_SPEED(0): Standard-mode (Sm) up to 100 kHz and Fast-mode (Fm) up to 400 kHz*/
/* Find and set baudrate. Read speed configuration. Set transfer
* speed: SERCOM_I2CM_CTRLA_SPEED(0): Standard-mode (Sm) up to 100
* kHz and Fast-mode (Fm) up to 400 kHz */
switch (speed) {
case I2C_SPEED_NORMAL:
tmp_baud = (int32_t)(((clock_source_speed + (2*(100000)) - 1) / (2*(100000))) - 5);
@ -276,7 +277,8 @@ int i2c_read_regs(i2c_t dev, uint8_t address, uint8_t reg, char *data, int lengt
/* start transmission and send slave address */
_start(i2c, address, I2C_FLAG_WRITE);
/* send register address/command and wait for complete transfer to be finished*/
/* send register address/command and wait for complete transfer to
* be finished */
_write(i2c, (char *)(&reg), 1);
return i2c_read_bytes(dev, address, data, length);
}
@ -328,7 +330,7 @@ int i2c_write_regs(i2c_t dev, uint8_t address, uint8_t reg, char *data, int leng
/* start transmission and send slave address */
_start(i2c, address, I2C_FLAG_WRITE);
/* send register address and wait for complete transfer to be finished*/
/* send register address and wait for complete transfer to be finished */
_write(i2c, (char *)(&reg), 1);
/* write data to register */
_write(i2c, data, length);
@ -369,14 +371,14 @@ static void _start(SercomI2cm *dev, uint8_t address, uint8_t rw_flag)
{
uint32_t timeout_counter = 0;
/*Wait for hardware module to sync*/
/* Wait for hardware module to sync */
DEBUG("Wait for device to be ready\n");
while(dev->SYNCBUSY.reg & SERCOM_I2CM_SYNCBUSY_MASK);
/* Set action to ACK. */
dev->CTRLB.reg &= ~SERCOM_I2CM_CTRLB_ACKACT;
/* Send Start | Address | Write/Read */
/* Send Start | Address | Write/Read */
DEBUG("Generate start condition by sending address\n");
dev->ADDR.reg = (address << 1) | rw_flag | (0 << SERCOM_I2CM_ADDR_HS_Pos);
@ -390,7 +392,8 @@ static void _start(SercomI2cm *dev, uint8_t address, uint8_t rw_flag)
}
/* Check for address response error unless previous error is detected. */
/* Check for error and ignore bus-error; workaround for BUSSTATE stuck in BUSY */
/* Check for error and ignore bus-error; workaround for BUSSTATE
* stuck in BUSY */
if (dev->INTFLAG.reg & SERCOM_I2CM_INTFLAG_SB) {
/* Clear write interrupt flag */
dev->INTFLAG.reg = SERCOM_I2CM_INTFLAG_SB;
@ -424,7 +427,7 @@ static inline void _write(SercomI2cm *dev, char *data, int length)
return;
}
/*Wait for hardware module to sync*/
/* Wait for hardware module to sync */
while(dev->SYNCBUSY.reg & SERCOM_I2CM_SYNCBUSY_MASK);
DEBUG("Written %i byte to data reg, now waiting for DR to be empty again\n", buffer_counter);
@ -463,7 +466,7 @@ static inline void _read(SercomI2cm *dev, char *data, int length)
return;
}
/*Wait for hardware module to sync*/
/* Wait for hardware module to sync */
while(dev->SYNCBUSY.reg & SERCOM_I2CM_SYNCBUSY_MASK);
/* Save data to buffer. */
data[count] = dev->DATA.reg;
@ -479,12 +482,12 @@ static inline void _read(SercomI2cm *dev, char *data, int length)
}
count++;
}
/*Send NACK before STOP*/
/* Send NACK before STOP */
dev->CTRLB.reg |= SERCOM_I2CM_CTRLB_ACKACT;
}
static inline void _stop(SercomI2cm *dev)
{
/*Wait for hardware module to sync*/
/* Wait for hardware module to sync */
while(dev->SYNCBUSY.reg & SERCOM_I2CM_SYNCBUSY_MASK);
/* Stop command */
dev->CTRLB.reg |= SERCOM_I2CM_CTRLB_CMD(3);