Commit Graph

36 Commits

Author SHA1 Message Date
Lee Jones 25d94a11db mfd: cros_ec_spi: Remove unused variable 'request'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2016-10-04 15:48:05 +01:00
Lee Jones 8827a642a4 mfd: cros_ec_spi: Repair comparison ordering issue
WARNING: Comparisons should place the constant on the right side of the test
+       BUG_ON(EC_MSG_PREAMBLE_COUNT > ec_dev->din_size);

WARNING: Comparisons should place the constant on the right side of the test
+       BUG_ON(EC_MSG_PREAMBLE_COUNT > ec_dev->din_size);

total: 0 errors, 2 warnings, 731 lines checked

Signed-off-by: Lee Jones <lee.jones@linaro.org>
2016-01-14 08:44:01 +00:00
Nicolas Boichat 6d6e44a953 mfd: cros ec: Lock the SPI bus while holding chipselect
cros_ec_cmd_xfer_spi and cros_ec_pkt_xfer_spi generally work like
this:
 - Pull CS down (active), wait a bit, then send a command
 - Wait for response (multiple requests)
 - Wait a while, pull CS up (inactive)

These operations, individually, lock the SPI bus, but there is
nothing preventing the SPI framework from interleaving messages
intended for other devices as the bus is unlocked in between.

This is a problem as the EC expects CS to be held low for the
whole duration.

Solution: Lock the SPI bus during the whole transaction, to make
sure that no other messages can be interleaved.

Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2016-01-11 06:07:51 +00:00
Andrew F. Davis 3821a065f5 spi: Drop owner assignment from spi_drivers
An spi_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-28 10:30:17 +09:00
Javier Martinez Canillas a78ea195f7 mfd: cros_ec: spi: Add OF match table
The Documentation/devicetree/bindings/mfd/cros-ec.txt DT binding doc lists
"google,cros-ec-spi" as a compatible string but the corresponding driver
does not have an OF match table. Add the table to the driver so the SPI
core can do an OF style match.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-08-24 15:27:59 +01:00
Alexandru M Stan ff4378f4b8 mfd: cros_ec: spi: Add delay for asserting CS
Some ECs need a little time for waking up before they can accept
SPI data at a high speed. This is configurable via a DT property
"google,cros-ec-spi-pre-delay".

This patch makes the cros_ec_spi driver to cause a delay before
the beginning of a SPI transaction, to make sure that the EC has
already woken up, if the property has been defined in the DTS.

Signed-off-by: Alexandru M Stan <amstan@chromium.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-06-15 13:18:24 +01:00
Gwendal Grignou 57b33ff077 mfd: cros_ec: Support multiple EC in a system
Chromebooks can have more than one Embedded Controller so the
cros_ec device id has to be incremented for each EC registered.

Add a new structure to represent multiple EC as different char
devices (e.g: /dev/cros_ec, /dev/cros_pd). It connects to
cros_ec_device and allows sysfs inferface for cros_pd.

Also reduce number of allocated objects, make chromeos sysfs
class object a static and add refcounting to prevent object
deletion while command is in progress.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-06-15 13:18:23 +01:00
Stephen Barber d365407079 mfd: cros_ec: add bus-specific proto v3 code
Add proto v3 support to the SPI, I2C, and LPC.

Signed-off-by: Stephen Barber <smbarber@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-06-15 13:18:22 +01:00
Stephen Barber 2c7589af3c mfd: cros_ec: add proto v3 skeleton
Add support in cros_ec.c to handle EC host command protocol v3.
For v3+, probe for maximum shared protocol version and max
request, response, and passthrough sizes. For now, this will
always fall back to v2, since there is no bus-specific code
for handling proto v3 packets.

Signed-off-by: Stephen Barber <smbarber@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-06-15 13:18:21 +01:00
Javier Martinez Canillas a841178445 mfd: cros_ec: Use a zero-length array for command data
Commit 1b84f2a4cd ("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: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-06-15 13:18:19 +01:00
Gwendal Grignou e7b707f968 mfd: cros_ec: Remove parent field
Parent and device were pointing to the same device structure.

Parent is unused, removed.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Stephen Barber <smbarber@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Puthikorn Voravootivat <puthik@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-06-15 13:18:17 +01:00
Andrew Bresticker 63427530fa mfd: cros_ec: move locking into cros_ec_cmd_xfer
Now that there's a central cros_ec_cmd_xfer(), move the locking
out of the SPI driver.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-10-06 21:29:50 +01:00
Doug Anderson 659e142be0 mfd: cros_ec: Delay for 50ms when we see EC_CMD_REBOOT_EC
If someone sends a EC_CMD_REBOOT_EC to the EC, the EC will likely be
unresponsive for quite a while.  Add a delay to the end of the command
to prevent random failures of future commands.

NOTES:
* This could be optimized a bit by simply delaying the next command
  sent, but EC_CMD_REBOOT_EC is such a rare command that the extra
  complexity doesn't seem worth it.
* This is a bit of an "ugly hack" since the SPI driver is effectively
  snooping on the communication and making a lot of assumptions.  It
  would be nice to architect in some better solution long term.
* This same logic probably needs to be applied to the i2c driver.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-10-06 21:28:48 +01:00
Linus Torvalds 54c72d5987 == Changes to existing drivers ==
- Checkpatch fixes throughout the subsystem
   - Use Regmap to handle IRQs in max77686, extcon-max77693 and mc13xxx-core
   - Use DMA in rtsx_pcr
   - Restrict building on unsupported architectures on timberdale, cs5535
   - SPI hardening in cros_ec_spi
   - More robust error handing in asic3, cros_ec, ab8500-debugfs,
         max77686 and pcf50633-core
   - Reorder PM runtime and regulator handing during shutdown in arizona
   - Enable wakeup in cros_ec_spi
   - Unused variable/code clean-up in pm8921-core, cros_ec, htc-i2cpld,
         tps65912-spi, wm5110-tables and ab8500-debugfs
   - Add regulator handing into suspend() in sec-core
   - Remove pointless wrapper functions in extcon-max77693 and i2c-cros-ec-tunnel
   - Use cross-architecture friendly data sizes in stmpe-i2c, arizona,
         max77686 and tps65910
   - Device Tree documentation updates throughout
   - Provide power management support in max77686
   - Few OF clean-ups in max77686
   - Use manged resources in tps6105x
 
  == New drivers/supported devices ==
   - Add support for s2mpu02 to sec-core
   - Add support for Allwinner A32 to sun6i-prcm
   - Add support for Maxim 77802 in max77686
   - Add support for DA9063 AD in da9063
   - Add new driver for Intel PMICs (generic) and specifically Crystal Cove
 
  == (Re-)moved drivers ==
   - Move out keyboard functionality cros_ec ==> input/keyboard/cros_ec_keyb
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJT40p7AAoJEFGvii+H/HdhTo0P/1GuZyvCAJCeqt2oN1gcloIe
 Hgf5rEo/PVPh3T9vHA7GCbWhgtdxfJI8FxrQYvU7Dw5cEMlmvl5p/ZHNPIProv97
 uI59JO67roLpXZP+aYX8BzXcplYkaR/ah16o/ePtaOCwGrXDz+TtJiHEVVN/8bAG
 PWsdcDNBC8byP7BZ/8zFdu6pX4800eRZ0KgeBH+u4k6UDor7M6LkQrxF1hJhU1Bv
 z14Q2wKQufhbcyEtQWcYc6M8hignD1Ioyd4I8mnEJs0EUiABfGUEk/K/G4Z5Q7Sv
 eRIEPZCd1CEBKD5JQcPXyE1QGdG9GiD15PLmctPA4VY1V+9c5/Hoq0TLoxlAQNWA
 gUr7WSqJ+KT2Nch0WVr/MdP8l0jPYfboWbsd/apj4GK0/9quwJNkGUxx0mCdCXyg
 9ylitwUrmlrd4CEKjybfEuTQB52Jvcdq24fnNYHHn1TGppZH6w7LVvdwSW7UcjF0
 Y48hTImYYnVAlWl5lE5xVQTWD/3hseAcoWTsdSORSWJbkCfAhJUg/Gn5bH/Fkwhs
 /aWYPvkF+m47PoudZ9Z8qB5OTO4uz/Q9uEBBf2/k4Yy95vl2IZdy9VqS5tYG67e7
 LLdAZvG5hjEwDi3OwcwGSdZ/kRB5Hgq/YvpqjItle86CKj0ECdAqL/PfqLISgJq9
 x3zSuWMRLcNoyhc2HnBj
 =2cNI
 -----END PGP SIGNATURE-----

Merge tag 'mfd-for-linus-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd

Pull MFD update from Lee Jones:
 "Changes to existing drivers:
   - checkpatch fixes throughout the subsystem
   - use Regmap to handle IRQs in max77686, extcon-max77693 and
     mc13xxx-core
   - use DMA in rtsx_pcr
   - restrict building on unsupported architectures on timberdale,
     cs5535
   - SPI hardening in cros_ec_spi
   - more robust error handing in asic3, cros_ec, ab8500-debugfs,
     max77686 and pcf50633-core
   - reorder PM runtime and regulator handing during shutdown in arizona
   - enable wakeup in cros_ec_spi
   - unused variable/code clean-up in pm8921-core, cros_ec, htc-i2cpld,
     tps65912-spi, wm5110-tables and ab8500-debugfs
   - add regulator handing into suspend() in sec-core
   - remove pointless wrapper functions in extcon-max77693 and
     i2c-cros-ec-tunnel
   - use cross-architecture friendly data sizes in stmpe-i2c, arizona,
     max77686 and tps65910
   - devicetree documentation updates throughout
   - provide power management support in max77686
   - few OF clean-ups in max77686
   - use manged resources in tps6105x

  New drivers/supported devices:
   - add support for s2mpu02 to sec-core
   - add support for Allwinner A32 to sun6i-prcm
   - add support for Maxim 77802 in max77686
   - add support for DA9063 AD in da9063
   - new driver for Intel PMICs (generic) and specifically Crystal Cove

  (Re-)moved drivers ==
   - move out keyboard functionality cros_ec ==> input/keyboard/cros_ec_keyb"

* tag 'mfd-for-linus-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (101 commits)
  MAINTAINERS: Update MFD repo location
  mfd: omap-usb-host: Fix improper mask use.
  mfd: arizona: Only free the CTRLIF_ERR IRQ if we requested it
  mfd: arizona: Add missing handling for ISRC3 under/overclocked
  mfd: wm5110: Add new interrupt register definitions
  mfd: arizona: Rename thermal shutdown interrupt
  mfd: wm5110: Add in the output done interrupts
  mfd: wm5110: Remove non-existant interrupts
  mfd: tps65912-spi: Remove unused variable
  mfd: htc-i2cpld: Remove unused code
  mfd: da9063: Add support for AD silicon variant
  mfd: arizona: Map MICVDD from extcon device to the Arizona core
  mfd: arizona: Add MICVDD to mapped regulators for wm8997
  mfd: max77686: Ensure device type IDs are architecture agnostic
  mfd: max77686: Add Maxim 77802 PMIC support
  mfd: tps6105x: Use managed resources when allocating memory
  mfd: wm8997-tables: Suppress 'line over 80 chars' warnings
  mfd: kempld-core: Correct a variety of checkpatch warnings
  mfd: ipaq-micro: Fix coding style errors/warnings reported by checkpatch
  mfd: si476x-cmd: Remedy checkpatch style complains
  ...
2014-08-07 17:17:39 -07:00
Thomas Gleixner 154adc14b1 mfd: cros_ec_spi: Use ktime_get_ns()
Replace the ever recurring:
	ts = ktime_get_ts();
	ns = timespec_to_ns(&ts);
with
	ns = ktime_get_ns();

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 15:01:38 -07:00
Bill Richardson 12ebc8a50b mfd: cros_ec: ec_dev->cmd_xfer() returns number of bytes received from EC
When communicating with the EC, the cmd_xfer() function should return the
number of bytes it received from the EC, or negative on error.

Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-07-09 14:58:20 +01:00
Bill Richardson 6db07b6336 mfd: cros_ec: Check result code from EC messages
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: Bill Richardson <wfrichar@chromium.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-07-09 14:58:19 +01:00
Bill Richardson 533cec8f34 mfd: cros_ec: cleanup: remove unused fields from struct cros_ec_device
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: Bill Richardson <wfrichar@chromium.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-07-09 14:58:18 +01:00
Bill Richardson 5d4773e27e mfd: cros_ec: Use struct cros_ec_command to communicate with the EC
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: Bill Richardson <wfrichar@chromium.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-07-09 14:58:17 +01:00
Simon Glass 9c5edb6c45 mfd: cros_ec: Detect in-progress commands
Some commands take a while to execute. Use -EAGAIN to signal this to the
caller.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-07-09 14:58:16 +01:00
Bill Richardson 7e6cb5b4db mfd: cros_ec: Tweak struct cros_ec_device for clarity
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: Bill Richardson <wfrichar@chromium.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-07-09 14:58:16 +01:00
Prathyush K fb50497ce2 mfd: cros_ec_spi: Set wakeup capability
Set the device as wakeup capable and register the wakeup source.

Note: Though it makes more sense to have the SPI framework do this,
(either via device tree or by board_info)
this change is as per an existing mail chain:
https://lkml.org/lkml/2009/8/27/291

Signed-off-by: Prathyush K <prathyush.k@samsung.com>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-07-09 14:58:06 +01:00
Doug Anderson 967580598f mfd: cros_ec: spi: Fix end of transfer on devices with no spi-msg-delay
cros_ec_spi makes the assumption that a 0-length message will put the
spi chip select back to normal (non cs_toggle mode).  This used to be
the case back on kernel-3.8 on the spi-s3c64xx driver but doesn't
appear to be true anymore.  It seems like it was a pretty questionable
assumption to begin with, so let's fix the code to be more robust.  We
know that a message with a single 0-length segment _will_ put things
back in order.  Change cros_ec_spi to handle this.

This wasn't a problem on the main user of cros_ec_spi upstream (tegra)
because it specified 'google,cros-ec-spi-msg-delay'.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-07-09 14:58:00 +01:00
Doug Anderson 9c0b54a120 mfd: cros_ec: spi: Increase cros_ec_spi deadline from 5ms to 100ms
We're adding i2c tunneling to the list of things that goes over
cros_ec.  i2c tunneling can be slooooooow, so increase our deadline to
100ms to account for that.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Andrew Bresticker <abrestic@chromium.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-06-03 08:11:48 +01:00
Doug Anderson c9a81d67ce mfd: cros_ec: spi: Make the cros_ec_spi timeout more reliable
The cros_ec_spi transfer had two problems with its timeout code:

1. It looked at the timeout even in the case that it found valid data.
2. If the cros_ec_spi code got switched out for a while, it's possible
   it could get a timeout after a single loop.  Let's be paranoid and
   make sure we do one last transfer after the timeout expires.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Andrew Bresticker <abrestic@chromium.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-06-03 08:11:47 +01:00
Doug Anderson 362196e5d0 mfd: cros_ec: spi: Add mutex to cros_ec_spi
The main transfer function for cros_ec_spi can be called by more than
one client at a time.  Make sure that those clients don't stomp on
each other by locking the bus for the duration of the transfer
function.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Andrew Bresticker <abrestic@chromium.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-06-03 08:11:46 +01:00
David Hendricks 1fe368665b mfd: cros_ec: spi: Calculate delay between transfers correctly
To avoid spamming the EC we calculate the time between the previous
transfer and the current transfer and force a delay if the time delta
is too small.

However, a small miscalculation causes the delay period to be
far too short. Most noticably this impacts commands with a long
turnaround time such as EC firmware reads and writes.

Signed-off-by: David Hendricks <dhendrix@chromium.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Andrew Bresticker <abrestic@chromium.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-06-03 08:11:46 +01:00
Rhyland Klein 01e73c89cf mfd: cros ec: spi: Add delay for raising CS
The EC has specific timing it requires. Add support for an optional delay
after raising CS to fix timing issues. This is configurable based on
a DT property "google,cros-ec-spi-msg-delay".

If this property isn't set, then no delay will be added. However, if set
it will cause a delay equal to the value passed to it to be inserted at
the end of a transaction.

Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Reviewed-by: Bernie Thompson <bhthompson@chromium.org>
Reviewed-by: Andrew Bresticker <abrestic@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-01-21 08:28:06 +00:00
Thierry Reding daf93d2287 mfd: cros ec: spi: Use 0 instead of '\0' consistently
memset() was being called with the second parameter set to '\0', which
is equivalent but longer than the more canonical 0. Update the code to
use the latter variant consistently across the driver.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-01-21 08:28:05 +00:00
Thierry Reding ea0f8b0b67 mfd: cros ec: spi: Use correct module license
According to the header comment in the source file the driver is
licensed under GPL v2, so update MODULE_LICENSE() to match that.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-01-21 08:28:04 +00:00
Thierry Reding 9922b4129c mfd: cros ec: spi: Use consistent function names
Rename cros_ec_{probe,remove}_spi() to cros_ec_spi_{probe,remove}() for
consistency.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-01-21 08:13:34 +00:00
Thierry Reding 9e146f4330 mfd: cros ec: spi: Fix debug output
The dev_cont() symbol doesn't exist, so replace it with pr_cont(). While
at it, also append a newline to the debug output to make it look nicer.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-01-06 09:13:23 +00:00
Derek Basehore 49f91ac331 mfd: cros ec: spi: Increase EC transaction delay
50 us is not a long enough delay between EC transactions. At least 70 us
are needed for the 16 MHz STM32L part. Increase the delay to 200 us for
an extra safety margin.

Reviewed-by: Randall Spangler <rspangler@chromium.org>
Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-01-06 09:13:23 +00:00
Geert Uytterhoeven c34924b950 mfd: cros_ec_spi: Use %z to format pointer differences
Before commit 5c29e47e6a ("mfd: cros_ec_spi:
Warnings fix"), 64-bit compiles gave the following warnings:

drivers/mfd/cros_ec_spi.c: In function 'cros_ec_spi_receive_response':
drivers/mfd/cros_ec_spi.c:123:5: warning: format '%d' expects argument of type 'int', but argument 4 has type 'long int' [-Wformat]
drivers/mfd/cros_ec_spi.c:157:3: warning: format '%d' expects argument of type 'int', but argument 6 has type 'long int' [-Wformat]
drivers/mfd/cros_ec_spi.c:181:2: warning: format '%d' expects argument of type 'int', but argument 4 has type 'long int' [-Wformat]

After that commit, 32-bit compiles give:

drivers/mfd/cros_ec_spi.c: In function ‘cros_ec_spi_receive_response’:
drivers/mfd/cros_ec_spi.c:123: warning: format ‘%ld’ expects type ‘long int’, but argument 4 has type ‘int’
drivers/mfd/cros_ec_spi.c:157: warning: format ‘%ld’ expects type ‘long int’, but argument 6 has type ‘int’
drivers/mfd/cros_ec_spi.c:181: warning: format ‘%ld’ expects type ‘long int’, but argument 4 has type ‘int’

Use %z to format pointer differences to kill the warnings on both 32-bit
and 64-bit.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2013-05-16 19:14:06 +02:00
Samuel Ortiz 5c29e47e6a mfd: cros_ec_spi: Warnings fix
To silent those:

 CC [M]  drivers/mfd/cros_ec_spi.o
drivers/mfd/cros_ec_spi.c: In function ‘cros_ec_spi_receive_response’:
drivers/mfd/cros_ec_spi.c:123:5: warning: format ‘%d’ expects argument of type
‘int’, but argument 4 has type ‘long int’ [-Wformat]
drivers/mfd/cros_ec_spi.c:157:3: warning: format ‘%d’ expects argument of type
‘int’, but argument 6 has type ‘long int’ [-Wformat]
drivers/mfd/cros_ec_spi.c:181:2: warning: format ‘%d’ expects argument of type
‘int’, but argument 4 has type ‘long int’ [-Wformat]

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2013-04-05 11:20:13 +02:00
Simon Glass a17d94f0b6 mfd: Add ChromeOS EC SPI driver
This uses a SPI bus to talk to the ChromeOS EC. The protocol
is defined by the EC and is fairly simple, with a length byte,
checksum, command byte and version byte (to permit easy creation
of new commands).

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2013-04-05 11:20:13 +02:00