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Added I2CSlave support for lpc812 #881

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Feb 11, 2015
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2 changes: 2 additions & 0 deletions libraries/mbed/hal/i2c_api.h
Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,8 @@ void i2c_slave_mode (i2c_t *obj, int enable_slave);
int i2c_slave_receive(i2c_t *obj);
int i2c_slave_read (i2c_t *obj, char *data, int length);
int i2c_slave_write (i2c_t *obj, const char *data, int length);
int i2c_slave_byte_read(i2c_t *obj, int last);
int i2c_slave_byte_write(i2c_t *obj, int data);
void i2c_slave_address(i2c_t *obj, int idx, uint32_t address, uint32_t mask);
#endif

Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -100,14 +100,18 @@
// </h>
// </e>
*/

// 1 == IRC 12Mhz 2 == System Oscillator 12Mhz Xtal:
#define CLOCK_SETUP 1
//use PLL for IRC
#define SYSOSCCTRL_Val 0x00000000 // Reset: 0x000
#define WDTOSCCTRL_Val 0x00000000 // Reset: 0x000
#define SYSPLLCTRL_Val 0x00000041 // Reset: 0x000
#define SYSPLLCLKSEL_Val 0x00000000 // Reset: 0x000
#define MAINCLKSEL_Val 0x00000003 // Reset: 0x000
#define SYSAHBCLKDIV_Val 0x00000001 // Reset: 0x001

#define SYSPLLCTRL_Val 0x00000041 // Reset: 0x000 MSEL=1 => M=2; PSEL=2 => 2P=8; PLLCLKOUT = (12x2) = 24MHz
//#define SYSPLLCTRL_Val 0x00000004 // Reset: 0x000 MSEL=4 => M=5; PSEL=0 => 2P=2; PLLCLKOUT = (12x5) = 60MHz
#define SYSPLLCLKSEL_Val 0x00000000 // Reset: 0x000 Select IRC
#define MAINCLKSEL_Val 0x00000003 // Reset: 0x000 MainClock = PLLCLKOUT
#define SYSAHBCLKDIV_Val 0x00000001 // Reset: 0x001 DIV=1 => SYSTEMCORECLK = 24 / 1 = 24MHz
//#define SYSAHBCLKDIV_Val 0x00000002 // Reset: 0x001 DIV=2 => SYSTEMCORECLK = 60 / 2 = 30MHz
/*
//-------- <<< end of configuration section >>> ------------------------------
*/
Expand Down Expand Up @@ -235,9 +239,10 @@
/*----------------------------------------------------------------------------
Clock Variable definitions
*----------------------------------------------------------------------------*/
uint32_t SystemCoreClock = __SYSTEM_CLOCK;/*!< System Clock Frequency (Core Clock)*/

uint32_t MainClock = __MAIN_CLOCK; /*!< Main Clock Frequency */
uint32_t SystemCoreClock = __SYSTEM_CLOCK; /*!< System Clock Frequency (Core Clock)*/

//Replaced SystemCoreClock with MainClock
/*----------------------------------------------------------------------------
Clock functions
*----------------------------------------------------------------------------*/
Expand Down Expand Up @@ -268,46 +273,46 @@ void SystemCoreClockUpdate (void) /* Get Core Clock Frequency */

switch (LPC_SYSCON->MAINCLKSEL & 0x03) {
case 0: /* Internal RC oscillator */
SystemCoreClock = __IRC_OSC_CLK;
MainClock = __IRC_OSC_CLK;
break;
case 1: /* Input Clock to System PLL */
switch (LPC_SYSCON->SYSPLLCLKSEL & 0x03) {
case 0: /* Internal RC oscillator */
SystemCoreClock = __IRC_OSC_CLK;
MainClock = __IRC_OSC_CLK;
break;
case 1: /* System oscillator */
SystemCoreClock = __SYS_OSC_CLK;
MainClock = __SYS_OSC_CLK;
break;
case 2: /* Reserved */
SystemCoreClock = 0;
MainClock = 0;
break;
case 3: /* CLKIN pin */
SystemCoreClock = __CLKIN_CLK;
MainClock = __CLKIN_CLK;
break;
}
break;
case 2: /* WDT Oscillator */
SystemCoreClock = wdt_osc;
MainClock = wdt_osc;
break;
case 3: /* System PLL Clock Out */
switch (LPC_SYSCON->SYSPLLCLKSEL & 0x03) {
case 0: /* Internal RC oscillator */
SystemCoreClock = __IRC_OSC_CLK * ((LPC_SYSCON->SYSPLLCTRL & 0x01F) + 1);
MainClock = __IRC_OSC_CLK * ((LPC_SYSCON->SYSPLLCTRL & 0x01F) + 1);
break;
case 1: /* System oscillator */
SystemCoreClock = __SYS_OSC_CLK * ((LPC_SYSCON->SYSPLLCTRL & 0x01F) + 1);
MainClock = __SYS_OSC_CLK * ((LPC_SYSCON->SYSPLLCTRL & 0x01F) + 1);
break;
case 2: /* Reserved */
SystemCoreClock = 0;
MainClock = 0;
break;
case 3: /* CLKIN pin */
SystemCoreClock = __CLKIN_CLK * ((LPC_SYSCON->SYSPLLCTRL & 0x01F) + 1);
MainClock = __CLKIN_CLK * ((LPC_SYSCON->SYSPLLCTRL & 0x01F) + 1);
break;
}
break;
}

SystemCoreClock /= LPC_SYSCON->SYSAHBCLKDIV;
SystemCoreClock = MainClock / LPC_SYSCON->SYSAHBCLKDIV;

}

Expand Down
252 changes: 249 additions & 3 deletions libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC81X/i2c_api.c
Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,8 @@
#include "cmsis.h"
#include "pinmap.h"

#if DEVICE_I2C

static const SWM_Map SWM_I2C_SDA[] = {
{7, 24},
};
Expand Down Expand Up @@ -75,6 +77,10 @@ void i2c_init(i2c_t *obj, PinName sda, PinName scl) {
i2c_interface_enable(obj);
}

//Actually Wrong. Spec says: First store Address in DAT before setting STA !
//Undefined state when using single byte I2C operations and too much delay
//between i2c_start and do_i2c_write(Address).
//Also note that lpc812 will immediately continue reading a byte when Address b0 == 1
inline int i2c_start(i2c_t *obj) {
int status = 0;
if (repeated_start) {
Expand All @@ -86,16 +92,15 @@ inline int i2c_start(i2c_t *obj) {
return status;
}



//Generate Stop condition and wait until bus is Idle
//Will also send NAK for previous RD
inline int i2c_stop(i2c_t *obj) {
int timeout = 0;

obj->i2c->MSTCTL = (1 << 2) | (1 << 0); // STP bit and Continue bit. Sends NAK to complete previous RD

while ((obj->i2c->STAT & ((7 << 1) | (1 << 0))) != ((0 << 1) | (1 << 0))) { //Spin until Ready (b0 == 1)and Status is Idle (b3..b1 == 000)
//Spin until Ready (b0 == 1)and Status is Idle (b3..b1 == 000)
while ((obj->i2c->STAT & ((7 << 1) | (1 << 0))) != ((0 << 1) | (1 << 0))) {
timeout ++;
if (timeout > 100000) return 1;
}
Expand Down Expand Up @@ -265,3 +270,244 @@ int i2c_byte_write(i2c_t *obj, int data) {

return ack;
}

#if DEVICE_I2CSLAVE

#define I2C_SLVDAT(x) (x->i2c->SLVDAT)
#define I2C_SLVSTAT(x) ((x->i2c->STAT >> 9) & (0x03))
#define I2C_SLVSI(x) ((x->i2c->STAT >> 8) & (0x01))
//#define I2C_SLVCNT(x) (x->i2c->SLVCTL = (1 << 0))
//#define I2C_SLVNAK(x) (x->i2c->SLVCTL = (1 << 1))

#if(0)
// Wait until the Slave Serial Interrupt (SI) is set
// Timeout when it takes too long.
static int i2c_wait_slave_SI(i2c_t *obj) {
int timeout = 0;
while (!(obj->i2c->STAT & (1 << 8))) {
timeout++;
if (timeout > 100000) return -1;
}
return 0;
}
#endif

void i2c_slave_mode(i2c_t *obj, int enable_slave) {

if (enable_slave) {
// obj->i2c->CFG &= ~(1 << 0); //Disable Master mode
obj->i2c->CFG |= (1 << 1); //Enable Slave mode
}
else {
// obj->i2c->CFG |= (1 << 0); //Enable Master mode
obj->i2c->CFG &= ~(1 << 1); //Disable Slave mode
}
}

// Wait for next I2C event and find out what is going on
//
int i2c_slave_receive(i2c_t *obj) {
int addr;

// Check if there is any data pending
if (! I2C_SLVSI(obj)) {
return 0; //NoData
};

// Check State
switch(I2C_SLVSTAT(obj)) {
case 0x0: // Slave address plus R/W received
// At least one of the four slave addresses has been matched by hardware.
// You can figure out which address by checking Slave address match Index in STAT register.

// Get the received address
addr = I2C_SLVDAT(obj) & 0xFF;
// Send ACK on address and Continue
obj->i2c->SLVCTL = (1 << 0);

if (addr == 0x00) {
return 2; //WriteGeneral
}
//check the RW bit
if ((addr & 0x01) == 0x01) {
return 1; //ReadAddressed
}
else {
return 3; //WriteAddressed
}
//break;

case 0x1: // Slave receive. Received data is available (Slave Receiver mode).
// Oops, should never get here...
obj->i2c->SLVCTL = (1 << 1); // Send NACK on received data, try to recover...
return 0; //NoData

case 0x2: // Slave transmit. Data can be transmitted (Slave Transmitter mode).
// Oops, should never get here...
I2C_SLVDAT(obj) = 0xFF; // Send dummy data for transmission
obj->i2c->SLVCTL = (1 << 0); // Continue and try to recover...
return 0; //NoData

case 0x3: // Reserved.
default: // Oops, should never get here...
obj->i2c->SLVCTL = (1 << 0); // Continue and try to recover...
return 0; //NoData
//break;
} //switch status
}

// The dedicated I2C Slave byte read and byte write functions need to be called
// from 'common' mbed I2CSlave API for devices that have separate Master and
// Slave engines such as the lpc812 and lpc1549.

//Called when Slave is addressed for Write, Slave will receive Data in polling mode
//Parameter last=1 means received byte will be NACKed.
int i2c_slave_byte_read(i2c_t *obj, int last) {
int data;

// Wait for data
while (!I2C_SLVSI(obj)); // Wait forever
//if (i2c_wait_slave_SI(obj) != 0) {return -2;} // Wait with timeout

// Dont bother to check State, were not returning it anyhow..
//if (I2C_SLVSTAT(obj)) == 0x01) {
// Slave receive. Received data is available (Slave Receiver mode).
//};

data = I2C_SLVDAT(obj) & 0xFF; // Get and store the received data
if (last) {
obj->i2c->SLVCTL = (1 << 1); // Send NACK on received data and Continue
}
else {
obj->i2c->SLVCTL = (1 << 0); // Send ACK on data and Continue to read
}

return data;
}


//Called when Slave is addressed for Read, Slave will send Data in polling mode
//
int i2c_slave_byte_write(i2c_t *obj, int data) {

// Wait until Ready
while (!I2C_SLVSI(obj)); // Wait forever
// if (i2c_wait_slave_SI(obj) != 0) {return -2;} // Wait with timeout

// Check State
switch(I2C_SLVSTAT(obj)) {
case 0x0: // Slave address plus R/W received
// At least one of the four slave addresses has been matched by hardware.
// You can figure out which address by checking Slave address match Index in STAT register.
// I2C Restart occurred
return -1;
//break;
case 0x1: // Slave receive. Received data is available (Slave Receiver mode).
// Should not get here...
return -2;
//break;
case 0x2: // Slave transmit. Data can be transmitted (Slave Transmitter mode).
I2C_SLVDAT(obj) = data & 0xFF; // Store the data for transmission
obj->i2c->SLVCTL = (1 << 0); // Continue to send

return 1;
//break;
case 0x3: // Reserved.
default:
// Should not get here...
return -3;
//break;
} // switch status
}


//Called when Slave is addressed for Write, Slave will receive Data in polling mode
//Parameter length (>=1) is the maximum allowable number of bytes. All bytes will be ACKed.
int i2c_slave_read(i2c_t *obj, char *data, int length) {
int count=0;

// Read and ACK all expected bytes
while (count < length) {
// Wait for data
while (!I2C_SLVSI(obj)); // Wait forever
// if (i2c_wait_slave_SI(obj) != 0) {return -2;} // Wait with timeout

// Check State
switch(I2C_SLVSTAT(obj)) {
case 0x0: // Slave address plus R/W received
// At least one of the four slave addresses has been matched by hardware.
// You can figure out which address by checking Slave address match Index in STAT register.
// I2C Restart occurred
return -1;
//break;

case 0x1: // Slave receive. Received data is available (Slave Receiver mode).
data[count] = I2C_SLVDAT(obj) & 0xFF; // Get and store the received data
obj->i2c->SLVCTL = (1 << 0); // Send ACK on data and Continue to read
break;

case 0x2: // Slave transmit. Data can be transmitted (Slave Transmitter mode).
case 0x3: // Reserved.
default: // Should never get here...
return -2;
//break;
} // switch status

count++;
} // for all bytes

return count; // Received the expected number of bytes
}


//Called when Slave is addressed for Read, Slave will send Data in polling mode
//Parameter length (>=1) is the maximum number of bytes. Exit when Slave byte is NACKed.
int i2c_slave_write(i2c_t *obj, const char *data, int length) {
int count;

// Send and all bytes or Exit on NAK
for (count=0; count < length; count++) {
// Wait until Ready for data
while (!I2C_SLVSI(obj)); // Wait forever
// if (i2c_wait_slave_SI(obj) != 0) {return -2;} // Wait with timeout

// Check State
switch(I2C_SLVSTAT(obj)) {
case 0x0: // Slave address plus R/W received
// At least one of the four slave addresses has been matched by hardware.
// You can figure out which address by checking Slave address match Index in STAT register.
// I2C Restart occurred
return -1;
//break;
case 0x1: // Slave receive. Received data is available (Slave Receiver mode).
// Should not get here...
return -2;
//break;
case 0x2: // Slave transmit. Data can be transmitted (Slave Transmitter mode).
I2C_SLVDAT(obj) = data[count] & 0xFF; // Store the data for transmission
obj->i2c->SLVCTL = (1 << 0); // Continue to send
break;
case 0x3: // Reserved.
default:
// Should not get here...
return -3;
//break;
} // switch status
} // for all bytes

return length; // Transmitted the max number of bytes
}


// Set the four slave addresses.
void i2c_slave_address(i2c_t *obj, int idx, uint32_t address, uint32_t mask) {
obj->i2c->SLVADR0 = (address & 0xFE); // Store address in address 0 register
obj->i2c->SLVADR1 = (0x00 & 0xFE); // Store general call write address in address 1 register
obj->i2c->SLVADR2 = (0x01); // Disable address 2 register
obj->i2c->SLVADR3 = (0x01); // Disable address 3 register
obj->i2c->SLVQUAL0 = (mask & 0xFE); // Qualifier mask for address 0 register. Any maskbit that is 1 will always be a match
}

#endif

#endif