MFC r274641, r274644, r274822, r276049:

Allow i2c bus speed to be configured via hints, FDT data, and sysctl.

Implement bus speed setting for OMAP4, AM335x, and imx5/6.

Fix the i2c bus speed divisors for TI OMAP4 and AM335x to give the
advertised 100, 400, and 1000 KHz speeds.

PR: 195009

MFC r267021:

FreeBSD, historically, has always used 8-bit addresses for i2c devices
(7-bit device address << 1), always leaving the room for the read/write
bit.

This commit convert ti_i2c and revert r259127 on bcm2835_bsc to make them
compatible with 8-bit addresses. Previous to this commit an i2c device
would have different addresses depending on the controller it was attached
to (by example, when compared to any iicbb(4) based i2c controller), which
was a pretty annoying behavior.

Also, update the PMIC i2c address on beaglebone* DTS files to match the
new address scheme.

Now the userland utilities need to do the correct slave address shifting
(but it is going to work with any i2c controller on the system).

Discussed with: ian

MFC r267834:

Clarify the expected usage of I2C 7-bit slave addresses on ioctl(2)
interface.

While here add the cross reference to iic(4) on iicbus(4).

CR: D210
Suggested by: jmg

MFC r274641, r274644, r274822, r276049:

Allow i2c bus speed to be configured via hints, FDT data, and sysctl.

Implement bus speed setting for OMAP4, AM335x, and imx5/6.

Fix the i2c bus speed divisors for TI OMAP4 and AM335x to give the
advertised 100, 400, and 1000 KHz speeds.

PR: 195009

MFC r267021:

FreeBSD, historically, has always used 8-bit addresses for i2c devices
(7-bit device address << 1), always leaving the room for the read/write
bit.

This commit convert ti_i2c and revert r259127 on bcm2835_bsc to make them
compatible with 8-bit addresses. Previous to this commit an i2c device
would have different addresses depending on the controller it was attached
to (by example, when compared to any iicbb(4) based i2c controller), which
was a pretty annoying behavior.

Also, update the PMIC i2c address on beaglebone* DTS files to match the
new address scheme.

Now the userland utilities need to do the correct slave address shifting
(but it is going to work with any i2c controller on the system).

Discussed with: ian

MFC r267834:

Clarify the expected usage of I2C 7-bit slave addresses on ioctl(2)
interface.

While here add the cross reference to iic(4) on iicbus(4).

CR: D210
Suggested by: jmg