diff options
Diffstat (limited to 'src/include/gpxe/i2c.h')
| -rw-r--r-- | src/include/gpxe/i2c.h | 68 |
1 files changed, 63 insertions, 5 deletions
diff --git a/src/include/gpxe/i2c.h b/src/include/gpxe/i2c.h index bfaee8fb..9d229546 100644 --- a/src/include/gpxe/i2c.h +++ b/src/include/gpxe/i2c.h @@ -8,6 +8,7 @@ */ #include <stdint.h> +#include <gpxe/bitbash.h> /** An I2C device * @@ -15,10 +16,35 @@ * is accessed via an I2C interface. */ struct i2c_device { - /** Address of this device */ - unsigned int address; - /** Flag indicating a ten-bit address format */ - int tenbit; + /** Address of this device + * + * The actual address sent on the bus will look like + * + * <start> <device address> <word address overflow> <r/w> + * + * The "word address overflow" is any excess bits from the + * word address, i.e. any portion that does not fit within the + * defined word address length. + */ + unsigned int dev_addr; + /** Device address length, in bytes + * + * This is the number of bytes that comprise the device + * address, defined to be the portion that terminates with the + * read/write bit. + */ + unsigned int dev_addr_len; + /** Word adddress length, in bytes + * + * This is the number of bytes that comprise the word address, + * defined to be the portion that starts after the read/write + * bit and ends before the first data byte. + * + * For some devices, this length will be zero (i.e. the word + * address is contained entirely within the "word address + * overflow"). + */ + unsigned int word_addr_len; }; /** An I2C interface @@ -91,6 +117,9 @@ enum { /** Delay required for bit-bashing operation */ #define I2C_UDELAY 5 +/** Maximum number of cycles to use when attempting a bus reset */ +#define I2C_RESET_MAX_CYCLES 32 + /** * Check presence of I2C device * @@ -106,6 +135,35 @@ static inline int i2c_check_presence ( struct i2c_interface *i2c, return i2c->write ( i2c, i2cdev, 0, NULL, 0 ); } -extern void init_i2c_bit_basher ( struct i2c_bit_basher *i2cbit ); +extern int init_i2c_bit_basher ( struct i2c_bit_basher *i2cbit, + struct bit_basher_operations *bash_op ); + +/** + * Initialise generic I2C EEPROM device + * + * @v i2cdev I2C device + */ +static inline __always_inline void +init_i2c_eeprom ( struct i2c_device *i2cdev, unsigned int dev_addr ) { + i2cdev->dev_addr = dev_addr; + i2cdev->dev_addr_len = 1; + i2cdev->word_addr_len = 1; +} + +/** + * Initialise Atmel AT24C11 + * + * @v i2cdev I2C device + */ +static inline __always_inline void +init_at24c11 ( struct i2c_device *i2cdev ) { + /* This chip has no device address; it must be the only chip + * on the bus. The word address is contained entirely within + * the device address field. + */ + i2cdev->dev_addr = 0; + i2cdev->dev_addr_len = 1; + i2cdev->word_addr_len = 0; +} #endif /* _GPXE_I2C_H */ |