The MFD driver should only have the logic to instantiate its child devices
and setup any shared resources that will be used by the subdevices drivers.

The cros_ec MFD is more complex than expected since it also has helpers to
communicate with the EC. So the driver will only get more bigger as other
protocols are supported in the future. So move the communication protocol
helpers to its own driver as drivers/platform/chrome/cros_ec_proto.c.
Suggested-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Acked-by: NLee Jones <lee.jones@linaro.org>
Acked-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Commit 1b84f2a4 ("mfd: cros_ec: Use fixed size arrays to transfer
data with the EC") modified the struct cros_ec_command fields to not
use pointers for the input and output buffers and use fixed length
arrays instead.

This change was made because the cros_ec ioctl API uses that struct
cros_ec_command to allow user-space to send commands to the EC and
to get data from the EC. So using pointers made the API not 64-bit
safe. Unfortunately this approach was not flexible enough for all
the use-cases since there may be a need to send larger commands
on newer versions of the EC command protocol.

So to avoid to choose a constant length that it may be too big for
most commands and thus wasting memory and CPU cycles on copy from
and to user-space or having a size that is too small for some big
commands, use a zero-length array that is both 64-bit safe and
flexible. The same buffer is used for both output and input data
so the maximum of these values should be used to allocate it.
Suggested-by: NGwendal Grignou <gwendal@chromium.org>
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Acked-by: NLee Jones <lee.jones@linaro.org>
Acked-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

If the EC device tree node has sub-nodes, try to instantiate them as
MFD sub-devices.  We can configure the EC features provided by the board.
Signed-off-by: NTodd Broch <tbroch@chromium.org>
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: NGwendal Grignou <gwendal@chromium.org>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

The ChromeOS EC character device is an user-space interface to
allow applications to access the Embedded Controller.

Add a cell for this device so it's spawned from the mfd driver.
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Acked-by: NLee Jones <lee.jones@linaro.org>
Tested-by: NGwendal Grignou <gwendal@chromium.org>
Reviewed-by: NGwendal Grignou <gwendal@chromium.org>
Signed-off-by: NOlof Johansson <olof@lixom.net>

The struct cros_ec_command will be used as an ioctl() argument for the
API to control the ChromeOS EC from user-space. So the data structure
has to be 64-bit safe to make it compatible between 32 and 64 avoiding
the need for a compat ioctl interface. Since pointers are self-aligned
to different byte boundaries, use fixed size arrays instead of pointers
for transferring ingoing and outgoing data with the Embedded Controller.

Also, re-arrange struct members by decreasing alignment requirements to
reduce the needing padding size.
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Acked-by: NLee Jones <lee.jones@linaro.org>
Tested-by: NGwendal Grignou <gwendal@chromium.org>
Reviewed-by: NGwendal Grignou <gwendal@chromium.org>
Signed-off-by: NOlof Johansson <olof@lixom.net>

When an EC command returns EC_RES_IN_PROGRESS, we need to query
the state of the EC until it indicates that it is no longer busy.
Do this in cros_ec_cmd_xfer() under the EC's mutex so that other
commands (e.g. keyboard, I2C passtru) aren't issued to the EC while
it is working on the in-progress command.

The 10 milliseconds delay and the number of retries are the values
that were used by the flashrom tool when retrying commands.
Signed-off-by: NAndrew Bresticker <abrestic@chromium.org>
Reviewed-by: NSimon Glass <sjg@chromium.org>
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Now that there's a central cros_ec_cmd_xfer(), move the locking
out of the SPI driver.
Signed-off-by: NAndrew Bresticker <abrestic@chromium.org>
Reviewed-by: NSimon Glass <sjg@chromium.org>
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Instead of having users of the ChromeOS EC call the interface-specific
cmd_xfer() callback directly, introduce a central cros_ec_cmd_xfer()
to use instead.  This will allow us to put all the locking and retry
logic in one place instead of duplicating it across the different
drivers.
Signed-off-by: NAndrew Bresticker <abrestic@chromium.org>
Reviewed-by: NSimon Glass <sjg@chromium.org>
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

If we receive EC interrupts after the cros_ec driver has probed, but
before the cros_ec_keyb driver has probed, the cros_ec IRQ handler
will not run the cros_ec_keyb notifier and the EC will leave the IRQ
line asserted.  The cros_ec IRQ handler then returns IRQ_HANDLED and
the resulting flood of interrupts causes the machine to hang.

Since the EC interrupt is currently only used for the keyboard, move
the setup and handling of the EC interrupt to the cros_ec_keyb driver.
Signed-off-by: NAndrew Bresticker <abrestic@chromium.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Acked-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Just because the host was able to talk to the EC doesn't mean that the EC
was happy with what it was told. Errors in communincation are not the same
as error messages from the EC itself.

This change lets the EC report its errors separately.

[dianders: Added common function to cros_ec.c]
Signed-off-by: NBill Richardson <wfrichar@chromium.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Remove the three wrapper functions that talk to the EC without passing all
the desired arguments and just use the underlying communication function
that passes everything in a struct intead.

This is internal code refactoring only. Nothing should change.
Signed-off-by: NBill Richardson <wfrichar@chromium.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NSimon Glass <sjg@chromium.org>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

struct cros_ec_device has a superfluous "name" field. We can get all the
debugging info we need from the existing ec_name and phys_name fields, so
let's take out the extra field.

The printout also has sufficient info in it without explicitly adding
the transport.  Before this change:
  cros-ec-spi spi2.0: Chrome EC (SPI)

After this change:
  cros-ec-spi spi2.0: Chrome EC device registered
Signed-off-by: NBill Richardson <wfrichar@chromium.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NSimon Glass <sjg@chromium.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

This is some internal structure reorganization / renaming to prepare
for future patches that will add a userspace API to cros_ec.  There
should be no visible changes.
Signed-off-by: NBill Richardson <wfrichar@chromium.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

The members of struct cros_ec_device were improperly commented, and
intermixed the private and public sections. This is just cleanup to make it
more obvious what goes with what.

[dianders: left lock in the structure but gave it the name that will
eventually be used.]
Signed-off-by: NBill Richardson <wfrichar@chromium.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

On ARM Chromebooks we have a few devices that are accessed by both the
AP (the main "Application Processor") and the EC (the Embedded
Controller).  These are:
* The battery (sbs-battery).
* The power management unit tps65090.

On the original Samsung ARM Chromebook these devices were on an I2C
bus that was shared between the AP and the EC and arbitrated using
some extranal GPIOs (see i2c-arb-gpio-challenge).

The original arbitration scheme worked well enough but had some
downsides:
* It was nonstandard (not using standard I2C multimaster)
* It only worked if the EC-AP communication was I2C
* It was relatively hard to debug problems (hard to tell if i2c issues
  were caused by the EC, the AP, or some device on the bus).

On the HP Chromebook 11 the design was changed to:
* The AP/EC comms were still i2c, but the battery/tps65090 were no
  longer on the bus used for AP/EC communication.  The battery was
  exposed to the AP through a limited i2c tunnel and tps65090 was
  exposed to the AP through a custom Linux driver.

On the Samsung ARM Chromebook 2 the scheme is changed yet again, now:
* The AP/EC comms are now using SPI for faster speeds.
* The EC's i2c bus is exposed to the AP through a full i2c tunnel.

The upstream "tegra124-venice2" uses the same scheme as the Samsung
ARM Chromebook 2, though it has a different set of components on the
other side of the bus.

This driver supports the scheme used by the Samsung ARM Chromebook 2.
Future patches to this driver could add support for the battery tunnel
on the HP Chromebook 11 (and perhaps could even be used to access
tps65090 on the HP Chromebook 11 instead of using a special driver,
but I haven't researched that enough).
Signed-off-by: NVincent Palatin <vpalatin@chromium.org>
Signed-off-by: NSimon Glass <sjg@chromium.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

This just updates include/linux/mfd/cros_ec_commands.h to match the
latest EC version (which is the One True Source for such things).  See
<https://chromium.googlesource.com/chromiumos/platform/ec>

[dianders: took today's ToT version from the Chromium OS EC; deleted
references to cros_ec_dev and cros_ec_lpc since those aren't upstream
yet]
Signed-off-by: NBill Richardson <wfrichar@chromium.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NSimon Glass <sjg@chromium.org>
Tested-by: NAndrew Bresticker <abrestic@chromium.org>
Tested-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

This module has always been GPL licensed. It was just missing the explicit
declaration to avoid tainting the kernel.
Signed-off-by: NBill Richardson <wfrichar@chromium.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

As of commit 03e361b2 ("mfd: Stop setting
refcounting pointers in original mfd_cell arrays"), the "cell" parameter of
mfd_add_devices() is "const" again. Hence make all cell data passed to
mfd_add_devices() const where possible.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

In order to fix those, when all cros code is modular:

ERROR: "cros_ec_prepare_tx" [drivers/mfd/cros_ec_spi.ko] undefined!
ERROR: "cros_ec_register" [drivers/mfd/cros_ec_spi.ko] undefined!
ERROR: "cros_ec_remove" [drivers/mfd/cros_ec_spi.ko] undefined!
ERROR: "cros_ec_suspend" [drivers/mfd/cros_ec_spi.ko] undefined!
ERROR: "cros_ec_resume" [drivers/mfd/cros_ec_spi.ko] undefined!
ERROR: "cros_ec_register" [drivers/mfd/cros_ec_i2c.ko] undefined!
ERROR: "cros_ec_remove" [drivers/mfd/cros_ec_i2c.ko] undefined!
ERROR: "cros_ec_suspend" [drivers/mfd/cros_ec_i2c.ko] undefined!
ERROR: "cros_ec_resume" [drivers/mfd/cros_ec_i2c.ko] undefined!
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

This is the base EC implementation, which provides a high level
interface to the EC for use by the rest of the kernel. The actual
communcations is dealt with by a separate protocol driver which
registers itself with this interface.

Interrupts are passed on through a notifier.

A simple message structure is used to pass messages to the
protocol driver.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Signed-off-by: NChe-Liang Chiou <clchiou@chromium.org>
Signed-off-by: NJonathan Kliegman <kliegs@chromium.org>
Signed-off-by: NLuigi Semenzato <semenzato@chromium.org>
Signed-off-by: NOlof Johansson <olofj@chromium.org>
Signed-off-by: NVincent Palatin <vpalatin@chromium.org>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>