snd_ac97_bus(9) [suse man page]
SND_AC97_BUS(9) Control/Mixer API SND_AC97_BUS(9) NAME
snd_ac97_bus - create an AC97 bus component SYNOPSIS
int snd_ac97_bus(struct snd_card * card, int num, struct snd_ac97_bus_ops * ops, void * private_data, struct snd_ac97_bus ** rbus); ARGUMENTS
card the card instance num the bus number ops the bus callbacks table private_data private data pointer for the new instance rbus the pointer to store the new AC97 bus instance. DESCRIPTION
Creates an AC97 bus component. An struct snd_ac97_bus instance is newly allocated and initialized. The ops table must include valid callbacks (at least read and write). The other callbacks, wait and reset, are not mandatory. The clock is set to 48000. If another clock is needed, set (*rbus)->clock manually. The AC97 bus instance is registered as a low-level device, so you don't have to release it manually. Returns zero if successful, or a negative error code on failure. COPYRIGHT
Kernel Hackers Manual 2.6. July 2010 SND_AC97_BUS(9)
Check Out this Related Man Page
IIC(4) BSD Kernel Interfaces Manual IIC(4) NAME
iic -- I2C generic I/O device driver SYNOPSIS
device iic #include <dev/iicbus/iic.h> DESCRIPTION
The iic device driver provides generic I/O to any iicbus(4) instance. In order to control I2C devices, use /dev/iic? with the following ioctls: I2CSTART (struct iiccmd) Sends the start condition to the slave specified by the slave element to the bus. All other elements are ignored. I2CRPTSTART (struct iiccmd) Sends the repeated start condition to the slave specified by the slave element to the bus. All other elements are ignored. I2CSTOP No argument is passed. Sends the stop condition to the bus. This terminates the current transaction. I2CRSTCARD (struct iiccmd) Resets the bus. The argument is completely ignored. I2CWRITE (struct iiccmd) Writes data to the iicbus(4). The bus should already be started. The slave element is ignored. The count ele- ment is the number of bytes to write. The last element is a boolean flag. It is non-zero when additional write commands will follow. The buf element is a pointer to the data to write to the bus. I2CREAD (struct iiccmd) Reads data from the iicbus(4). The bus should already be started. The slave element is ignored. The count element is the number of bytes to write. The last element is a boolean flag. It is non-zero when additional write commands will follow. The buf element is a pointer to where to store the data read from the bus. Short reads on the bus produce unde- fined results. I2CRDWR (struct iic_rdwr_data) Generic read/write interface. Allows for an arbitrary number of commands to be sent to an arbitrary num- ber of devices on the bus. A read transfer is specified if IIC_M_RD is set in flags. Otherwise the transfer is a write trans- fer. The slave element specifies the 7-bit address for the transfer. The len element is the length of the data. The buf ele- ment is a buffer for that data. This ioctl is intended to be Linux compatible. The following data structures are defined in <dev/iicbus/iic.h> and referenced above: struct iiccmd { u_char slave; int count; int last; char *buf; }; /* Designed to be compatible with linux's struct i2c_msg */ struct iic_msg { uint16_t slave; uint16_t flags; #define IIC_M_RD 0x0001 /* read vs write */ uint16_t len; /* msg legnth */ uint8_t * buf; }; struct iic_rdwr_data { struct iic_msg *msgs; uint32_t nmsgs; }; It is also possible to use read/write routines, then I2C start/stop handshake is managed by the iicbus(4) system. However, the address used for the read/write routines is the one passed to last I2CSTART ioctl(2) to this device. SEE ALSO
ioctl(2), read(2), write(2), iicbus(4) HISTORY
The iic manual page first appeared in FreeBSD 3.0. AUTHORS
This manual page was written by Nicolas Souchu and M. Warner Losh. BUGS
Only the I2CRDWR ioctl(2) is thread safe. All other interfaces suffer from some kind of race. BSD
September 6, 2006 BSD