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2018-12-18i2c: i2c-cros-ec-tunnel: Switch to SPDX identifier.Enric Balletbo i Serra1-10/+4
Adopt the SPDX license identifier headers to ease license compliance management. Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-01-29i2c: i2c-cros-ec-tunnel: Reduce logging noiseGuenter Roeck1-4/+4
If an i2c access through i2c-cros-ec-tunnel returns an error, the following log message is seen on the console. cros-ec-i2c-tunnel ff200000.spi:ec@0:i2c-tunnel: Error parsing EC i2c message -121 This can happen a lot if, for example, the i2c-detect command is executed. Since it is perfectly normal for an i2c controller to report an error, drop the message. Also, report -ENXIO instead of -EREMOTEIO if the access error is due to NAK from the device, and return -EIO instead of -EREMOTEIO for other errors, as suggested in Documentation/i2c/fault-codes. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-22i2c: don't print error when adding adapter failsWolfram Sang1-3/+1
The core will do this for us now. Signed-off-by: Wolfram Sang <wsa-dev@sang-engineering.com> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com> Acked-by: Peter Korsgaard <peter@korsgaard.com> Acked-by: Heiko Stuebner <heiko@sntech.de> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Thierry Reding <treding@nvidia.com> Acked-by: Ray Jui <ray.jui@broadcom.com> Acked-by: Vladimir Zapolskiy <vz@mleia.com> Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com> Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Acked-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-15i2c: cros-ec-tunnel: Fix usage of cros_ec_cmd_xfer()Brian Norris1-1/+1
cros_ec_cmd_xfer returns success status if the command transport completes successfully, but the execution result is incorrectly ignored. In many cases, the execution result is assumed to be successful, leading to ignored errors and operating on uninitialized data. We've recently introduced the cros_ec_cmd_xfer_status() helper to avoid these problems. Let's use it. [Regarding the 'Fixes' tag; there is significant refactoring since the driver's introduction, but the underlying logical error exists throughout I believe] Fixes: 9d230c9e4f4e ("i2c: ChromeOS EC tunnel driver") Cc: <stable@vger.kernel.org> # 9798ac6d32c1 mfd: cros_ec: Add cros_ec_cmd_xfer_status() helper Signed-off-by: Brian Norris <briannorris@chromium.org> Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-06-15mfd: cros_ec: Use a zero-length array for command dataJavier Martinez Canillas1-15/+30
Commit 1b84f2a4cd4a ("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>
2015-02-27mfd: cros_ec: Use fixed size arrays to transfer data with the ECJavier Martinez Canillas1-41/+10
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: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Acked-by: Lee Jones <lee.jones@linaro.org> Tested-by: Gwendal Grignou <gwendal@chromium.org> Reviewed-by: Gwendal Grignou <gwendal@chromium.org> Signed-off-by: Olof Johansson <olof@lixom.net>
2014-10-19Merge branch 'i2c/for-next' of ↵Linus Torvalds1-2/+13
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c updates from Wolfram Sang: "Highlights from the I2C subsystem for 3.18: - new drivers for Axxia AM55xx, and Hisilicon hix5hd2 SoC. - designware driver gained AMD support, exynos gained exynos7 support The rest is usual driver stuff. Hopefully no lowlights this time" * 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: i801: Add Device IDs for Intel Sunrise Point PCH i2c: hix5hd2: add i2c controller driver i2c-imx: Disable the clock on probe failure i2c: designware: Add support for AMD I2C controller i2c: designware: Rework probe() to get clock a bit later i2c: designware: Default to fast mode in case of ACPI i2c: axxia: Add I2C driver for AXM55xx i2c: exynos: add support for HSI2C module on Exynos7 i2c: mxs: detect No Slave Ack on SELECT in PIO mode i2c: cros_ec: Remove EC_I2C_FLAG_10BIT i2c: cros-ec-tunnel: Add of match table i2c: rcar: remove sign-compare flaw i2c: ismt: Use minimum descriptor size i2c: imx: Add arbitration lost check i2c: rk3x: Remove unlikely() annotations i2c: rcar: check for no IRQ in rcar_i2c_irq() i2c: rcar: make rcar_i2c_prepare_msg() *void* i2c: rcar: simplify check for last message i2c: designware: add support of platform data to set I2C mode i2c: designware: add support of I2C standard mode
2014-10-07i2c: i2c-cros-ec-tunnel: Set retries to 3Derek Basehore1-0/+3
Since the i2c bus can get wedged on the EC sometimes, set the number of retries to 3. Since we un-wedge the bus immediately after the wedge happens, this is the correct fix since only one transfer will fail. Signed-off-by: Derek Basehore <dbasehore@chromium.org> Reviewed-by: Doug Anderson <dianders@chromium.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-10-07mfd: cros_ec: stop calling ->cmd_xfer() directlyAndrew Bresticker1-1/+1
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: 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>
2014-09-30i2c: cros_ec: Remove EC_I2C_FLAG_10BITDoug Anderson1-2/+4
In <https://lkml.org/lkml/2014/6/10/265> pointed out that the 10-bit flag in the cros_ec_tunnel was useless. It went into a 16-bit flags field but was defined at (1 << 16). Since we have no 10-bit i2c devices on the other side of the tunnel on any known devices this was never a problem. Until we do it makes sense to remove this code. On the EC side the code to handle this flag was removed in <https://chromium-review.googlesource.com/204162>. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Doug Anderson <dianders@chromium.org> Reviewed-by: Simon Glass <sjg@chromium.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-09-30i2c: cros-ec-tunnel: Add of match tableSjoerd Simons1-0/+9
To enable the cros-ec-tunnel driver to be auto-loaded when build as a module add an of match table (and export it) to match the modalias information passed on to userspace as the Cros EC MFD driver registers the MFD subdevices with an of_compatibility string. Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk> Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-07-09mfd: cros_ec: ec_dev->cmd_xfer() returns number of bytes received from ECBill Richardson1-1/+1
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>
2014-07-09mfd: cros_ec: cleanup: Remove EC wrapper functionsBill Richardson1-4/+11
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: 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> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-06-03i2c: ChromeOS EC tunnel driverDoug Anderson1-0/+318
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: Vincent Palatin <vpalatin@chromium.org> Signed-off-by: Simon Glass <sjg@chromium.org> Signed-off-by: Doug Anderson <dianders@chromium.org> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Lee Jones <lee.jones@linaro.org>