mirror of https://github.com/marqs85/ossc.git
207 lines
6.6 KiB
C
207 lines
6.6 KiB
C
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#include "alt_types.h"
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#include "i2c_opencores_regs.h"
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#include "i2c_opencores.h"
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// #define I2C_DEBUG
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//int I2C_init(alt_u32 base,alt_u32 clk, alt_u32 speed)
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//int I2C_start(alt_u32 base, alt_u32 add, alt_u32 write);
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//alt_u32 I2C_read(alt_u32 base);
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//int I2C_write(alt_u32 base, alt_u8 data);
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//int I2C_stop(alt_u32 base);
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/* these functions are polled only. */
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/* all functions wait until the I2C is done before exiting */
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/****************************************************************
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int I2C_init
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This function inititlizes the prescalor for the scl
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and then enables the core. This must be run before
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any other i2c code is executed
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inputs
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base = the base address of the component
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clk = freuqency of the clock driving this component ( in Hz)
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speed = SCL speed ie 100K, 400K ... (in Hz)
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15-OCT-07 initial release
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*****************************************************************/
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void I2C_init(alt_u32 base,alt_u32 clk,alt_u32 speed)
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{
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alt_u32 prescale = (clk/( 5 * speed))-1;
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#ifdef I2C_DEBUG
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printf(" Initializing I2C at 0x%x, \n\twith clock speed 0x%x \n\tand SCL speed 0x%x \n\tand prescale 0x%x\n",base,clk,speed,prescale);
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#endif
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IOWR_I2C_OPENCORES_CTR(base, 0x00); /* turn off the core*/
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IOWR_I2C_OPENCORES_CR(base, I2C_OPENCORES_CR_IACK_MSK); /* clearn any pening IRQ*/
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IOWR_I2C_OPENCORES_PRERLO(base, (0xff & prescale)); /* load low presacle bit*/
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IOWR_I2C_OPENCORES_PRERHI(base, (0xff & (prescale>>8))); /* load upper prescale bit */
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IOWR_I2C_OPENCORES_CTR(base, I2C_OPENCORES_CTR_EN_MSK); /* turn on the core*/
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}
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/****************************************************************
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int I2C_start
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Sets the start bit and then sends the first byte which
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is the address of the device + the write bit.
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inputs
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base = the base address of the component
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add = address of I2C device
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read = 1== read 0== write
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return value
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0 if address is acknowledged
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1 if address was not acknowledged
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15-OCT-07 initial release
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*****************************************************************/
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int I2C_start(alt_u32 base, alt_u32 add, alt_u32 read)
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{
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#ifdef I2C_DEBUG
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printf(" Start I2C at 0x%x, \n\twith address 0x%x \n\tand read 0x%x \n\tand prescale 0x%x\n",base,add,read);
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#endif
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/* transmit the address shifted by one and the read/write bit*/
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IOWR_I2C_OPENCORES_TXR(base, ((add<<1) + (0x1 & read)));
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/* set start and write bits which will start the transaction*/
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IOWR_I2C_OPENCORES_CR(base, I2C_OPENCORES_CR_STA_MSK | I2C_OPENCORES_CR_WR_MSK );
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/* wait for the trnasaction to be over.*/
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while( IORD_I2C_OPENCORES_SR(base) & I2C_OPENCORES_SR_TIP_MSK);
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/* now check to see if the address was acknowledged */
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if(IORD_I2C_OPENCORES_SR(base) & I2C_OPENCORES_SR_RXNACK_MSK)
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{
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#ifdef I2C_DEBUG
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printf("\tNOACK\n");
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#endif
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return (I2C_NOACK);
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}
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else
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{
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#ifdef I2C_DEBUG
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printf("\tACK\n");
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#endif
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return (I2C_ACK);
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}
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}
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/****************************************************************
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int I2C_read
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assumes that any addressing and start
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has already been done.
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reads one byte of data from the slave. on the last read
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we don't acknowldge and set the stop bit.
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inputs
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base = the base address of the component
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last = on the last read there must not be a ack
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return value
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byte read back.
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15-OCT-07 initial release
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*****************************************************************/
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alt_u32 I2C_read(alt_u32 base,alt_u32 last)
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{
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#ifdef I2C_DEBUG
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printf(" Read I2C at 0x%x, \n\twith last0x%x\n",base,last);
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#endif
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if( last)
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{
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/* start a read and no ack and stop bit*/
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IOWR_I2C_OPENCORES_CR(base, I2C_OPENCORES_CR_RD_MSK |
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I2C_OPENCORES_CR_NACK_MSK | I2C_OPENCORES_CR_STO_MSK);
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}
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else
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{
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/* start read*/
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IOWR_I2C_OPENCORES_CR(base, I2C_OPENCORES_CR_RD_MSK );
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}
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/* wait for the trnasaction to be over.*/
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while( IORD_I2C_OPENCORES_SR(base) & I2C_OPENCORES_SR_TIP_MSK);
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/* now read the data */
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return (IORD_I2C_OPENCORES_RXR(base));
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}
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/****************************************************************
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int I2C_write
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assumes that any addressing and start
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has already been done.
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writes one byte of data from the slave.
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If last is set the stop bit set.
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inputs
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base = the base address of the component
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data = byte to write
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last = on the last read there must not be a ack
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return value
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0 if address is acknowledged
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1 if address was not acknowledged
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15-OCT-07 initial release
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*****************************************************************/
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alt_u32 I2C_write(alt_u32 base,alt_u8 data, alt_u32 last)
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{
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#ifdef I2C_DEBUG
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printf(" Read I2C at 0x%x, \n\twith data 0x%x,\n\twith last0x%x\n",base,data,last);
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#endif
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/* transmit the data*/
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IOWR_I2C_OPENCORES_TXR(base, data);
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if( last)
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{
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/* start a write with ack and stop bit*/
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IOWR_I2C_OPENCORES_CR(base, I2C_OPENCORES_CR_WR_MSK |
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I2C_OPENCORES_CR_STO_MSK);
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}
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else
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{
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/* start write with ack */
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IOWR_I2C_OPENCORES_CR(base, I2C_OPENCORES_CR_WR_MSK );
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}
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/* wait for the trnasaction to be over.*/
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while( IORD_I2C_OPENCORES_SR(base) & I2C_OPENCORES_SR_TIP_MSK);
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/* now check to see if the address was acknowledged */
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if(IORD_I2C_OPENCORES_SR(base) & I2C_OPENCORES_SR_RXNACK_MSK)
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{
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#ifdef I2C_DEBUG
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printf("\tNOACK\n");
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#endif
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return (I2C_NOACK);
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}
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else
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{
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#ifdef I2C_DEBUG
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printf("\tACK\n");
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#endif
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return (I2C_ACK);
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}
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}
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alt_u32 SPI_read(alt_u32 base)
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{
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/* start read*/
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IOWR_I2C_OPENCORES_CR(base, I2C_OPENCORES_CR_RD_MSK|I2C_OPENCORES_CR_NACK_MSK|I2C_OPENCORES_CR_SPIM_MSK );
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/* wait for the trnasaction to be over.*/
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while( IORD_I2C_OPENCORES_SR(base) & I2C_OPENCORES_SR_TIP_MSK);
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/* now read the data */
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return (IORD_I2C_OPENCORES_RXR(base));
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}
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void SPI_write(alt_u32 base,alt_u8 data) {
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/* transmit the data*/
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IOWR_I2C_OPENCORES_TXR(base, data);
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/* start write */
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IOWR_I2C_OPENCORES_CR(base, I2C_OPENCORES_CR_WR_MSK|I2C_OPENCORES_CR_NACK_MSK|I2C_OPENCORES_CR_SPIM_MSK );
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/* wait for the trnasaction to be over.*/
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while( IORD_I2C_OPENCORES_SR(base) & I2C_OPENCORES_SR_TIP_MSK);
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}
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