This enables debouncing of the I2C lines. The debounce period is
2 * the debounce register field value, in terms of the I2C block's main
clock. The Tegra TRM indicates that a setting yielding >50nS is
desirable. Hence, a setting of 2 => 4 clocks @ 72MHz => ~55nS.
Signed-off-by: NKen Radtke <kradtke@nvidia.com>
[swarren: Added commit description body,
 Fixed 80-column limit, Reverted file permission change]
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

A repeated start should be used for all but the last msg in an xfer.  The
NOSTART flag is for skipping the START frame (addr/rw)
Signed-off-by: NErik Gilling <konkers@android.com>
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

Re-init the I2C controller when an IRQ arrives with no
I2C_INT_STATUS bits set to indicate why the interrupt was sent.
Storms of such mystery interrupts are infrequently seen.

Dump some more status when these interrupts arrive.  Set an error
for the current request and wake up the requester (rather than
timing out the request or possibly silently ignoring the interrupts).

If the I2C block is inside the DVC, also ACK the DVC I2C transfer
done interrupt in the ISR error return path, as is done for the
normal return path.
Signed-off-by: NTodd Poynor <toddpoynor@google.com>
[swarren: Fix minor checkpatch whitespace issue, commit tag]
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

For Tegra i2c controller to function properly new slave mode must be
enabled.

swarren notes:

In particular, I found this was needed when working on enabling the
Tegra audio driver on the Seaboard board. There are two different PCB
layouts for this board; a "clamshell" version, which works just fine
without this change, and the original non-clamshell version, which needs
this change in order for I2C to operate correctly. Without it, I2C
probing fails for some devices, e.g. with:

wm8903 0-001a: Device with ID register 0 is not a WM8903
wm8903 0-001a: asoc: failed to probe CODEC wm8903.0-001a: -19
asoc: failed to instantiate card tegra-wm8903: -19
ALSA device list:
  No soundcards found.
Signed-off-by: NRakesh Iyer <riyer@nvidia.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Adds I2C bus driver for nVidia Tegra SoCs.  Tegra includes 4 I2C
controllers, one of which is inside the Dynamic Voltage Controller
and has a slightly different register map.
Signed-off-by: NColin Cross <ccross@android.com>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>