david/ipxe
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[bitbash] Add optional open() and close() methods for bit-bashing interfaces

Signed-off-by: Michael Brown <mcb30@ipxe.org>
This commit is contained in:
Michael Brown 2012-08-24 17:25:14 +01:00
parent 5676abead2
commit d1949f2737
3 changed files with 48 additions and 1 deletions

View File

@ -239,6 +239,7 @@ static int i2c_reset ( struct bit_basher *basher ) {
* pull SDA low while SCL is high (which creates a start
* condition).
*/
open_bit ( basher );
setscl ( basher, 0 );
setsda ( basher, 1 );
for ( i = 0 ; i < I2C_RESET_MAX_CYCLES ; i++ ) {
@ -251,6 +252,7 @@ static int i2c_reset ( struct bit_basher *basher ) {
i2c_stop ( basher );
DBGC ( basher, "I2CBIT %p reset after %d attempts\n",
basher, ( i + 1 ) );
close_bit ( basher );
return 0;
}
setscl ( basher, 0 );
@ -258,6 +260,7 @@ static int i2c_reset ( struct bit_basher *basher ) {
DBGC ( basher, "I2CBIT %p could not reset after %d attempts\n",
basher, i );
close_bit ( basher );
return -ETIMEDOUT;
}
@ -285,6 +288,8 @@ static int i2c_bit_read ( struct i2c_interface *i2c,
DBGC ( basher, "I2CBIT %p reading from device %x: ",
basher, i2cdev->dev_addr );
open_bit ( basher );
for ( ; ; data++, offset++ ) {
/* Select device for writing */
@ -312,6 +317,7 @@ static int i2c_bit_read ( struct i2c_interface *i2c,
DBGC ( basher, "%s\n", ( rc ? "failed" : "" ) );
i2c_stop ( basher );
close_bit ( basher );
return rc;
}
@ -339,6 +345,8 @@ static int i2c_bit_write ( struct i2c_interface *i2c,
DBGC ( basher, "I2CBIT %p writing to device %x: ",
basher, i2cdev->dev_addr );
open_bit ( basher );
for ( ; ; data++, offset++ ) {
/* Select device for writing */
@ -362,6 +370,7 @@ static int i2c_bit_write ( struct i2c_interface *i2c,
DBGC ( basher, "%s\n", ( rc ? "failed" : "" ) );
i2c_stop ( basher );
close_bit ( basher );
return rc;
}

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@ -163,6 +163,9 @@ static int spi_bit_rw ( struct spi_bus *bus, struct spi_device *device,
uint32_t tmp_address;
uint32_t tmp_address_detect;
/* Open bit-bashing interface */
open_bit ( &spibit->basher );
/* Deassert chip select to reset specified slave */
spi_bit_set_slave_select ( spibit, device->slave, DESELECT_SLAVE );
@ -214,6 +217,9 @@ static int spi_bit_rw ( struct spi_bus *bus, struct spi_device *device,
/* Deassert chip select on specified slave */
spi_bit_set_slave_select ( spibit, device->slave, DESELECT_SLAVE );
/* Close bit-bashing interface */
close_bit ( &spibit->basher );
return 0;
}

View File

@ -13,6 +13,18 @@ struct bit_basher;
/** Bit-bashing operations */
struct bit_basher_operations {
/**
* Open bit-bashing interface (optional)
*
* @v basher Bit-bashing interface
*/
void ( * open ) ( struct bit_basher *basher );
/**
* Close bit-bashing interface (optional)
*
* @v basher Bit-bashing interface
*/
void ( * close ) ( struct bit_basher *basher );
/**
* Set/clear output bit
*
@ -45,6 +57,26 @@ struct bit_basher {
struct bit_basher_operations *op;
};
/**
* Open bit-bashing interface
*
* @v basher Bit-bashing interface
*/
static inline void open_bit ( struct bit_basher *basher ) {
if ( basher->op->open )
basher->op->open ( basher );
}
/**
* Close bit-bashing interface
*
* @v basher Bit-bashing interface
*/
static inline void close_bit ( struct bit_basher *basher ) {
if ( basher->op->close )
basher->op->close ( basher );
}
extern void write_bit ( struct bit_basher *basher, unsigned int bit_id,
unsigned long data );
extern int read_bit ( struct bit_basher *basher, unsigned int bit_id );