Граф коммитов

3953 Коммитов

Автор SHA1 Сообщение Дата
Sowjanya Komatineni b67d4530cd i2c: tegra: Fix Maximum transfer size
Tegra194 supports maximum 64K Bytes transfer per packet.
Tegra186 and prior supports maximum 4K Bytes transfer per packet.

This patch fixes this payload difference between Tegra194 and prior
Tegra chipsets using separate i2c_adapter_quirks.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-01-11 00:15:04 +01:00
Yi Zeng 6ebec961d5 i2c: dev: prevent adapter retries and timeout being set as minus value
If adapter->retries is set to a minus value from user space via ioctl,
it will make __i2c_transfer and __i2c_smbus_xfer skip the calling to
adapter->algo->master_xfer and adapter->algo->smbus_xfer that is
registered by the underlying bus drivers, and return value 0 to all the
callers. The bus driver will never be accessed anymore by all users,
besides, the users may still get successful return value without any
error or information log print out.

If adapter->timeout is set to minus value from user space via ioctl,
it will make the retrying loop in __i2c_transfer and __i2c_smbus_xfer
always break after the the first try, due to the time_after always
returns true.

Signed-off-by: Yi Zeng <yizeng@asrmicro.com>
[wsa: minor grammar updates to commit message]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
2019-01-11 00:14:55 +01:00
Linus Torvalds 7671c14e6a Merge branch 'i2c/for-5.0' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 "I2C has only driver updates for you this time.

  Mostly new IDs/DT compatibles, also SPDX conversions, small cleanups.
  STM32F7 got FastMode+ and PM support, Axxia some reliabilty
  improvements"

* 'i2c/for-5.0' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (26 commits)
  i2c: Add Actions Semiconductor Owl family S700 I2C support
  dt-bindings: i2c: Add S700 support for Actions Semi Soc's
  i2c: ismt: Add support for Intel Cedar Fork
  i2c: tegra: Switch to SPDX identifier
  i2c: tegra: Add missing kerneldoc for some fields
  i2c: tegra: Cleanup kerneldoc comments
  i2c: axxia: support sequence command mode
  dt-bindings: i2c: rcar: Add r8a774c0 support
  dt-bindings: i2c: sh_mobile: Add r8a774c0 support
  i2c: sh_mobile: Add support for r8a774c0 (RZ/G2E)
  i2c: i2c-cros-ec-tunnel: Switch to SPDX identifier.
  i2c: powermac: Use of_node_name_eq for node name comparisons
  i2c-axxia: check for error conditions first
  i2c-axxia: dedicated function to set client addr
  dt-bindings: i2c: Use correct vendor prefix for Atmel
  i2c: tegra: replace spin_lock_irqsave with spin_lock in ISR
  eeprom: at24: add support for 24c2048
  dt-bindings: eeprom: at24: add "atmel,24c2048" compatible string
  i2c: i2c-stm32f7: add PM Runtime support
  i2c: sh_mobile: add support for r8a77990 (R-Car E3)
  ...
2019-01-05 18:13:35 -08:00
Parthiban Nallathambi 81482d13f3 i2c: Add Actions Semiconductor Owl family S700 I2C support
Add S700 to the list of devices supported by Owl I2C driver.

Add Actions Semiconductor Owl family S700 I2C driver.

Signed-off-by: Parthiban Nallathambi <pn@denx.de>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-01-03 20:36:18 +01:00
Jarkko Nikula 5cda2d86de i2c: ismt: Add support for Intel Cedar Fork
Add PCI ID for the Intel Cedar Fork iSMT SMBus controller.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
[wsa: kept sorting]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-01-03 20:02:32 +01:00
Linus Torvalds 769e47094d Kconfig updates for v4.21
- support -y option for merge_config.sh to avoid downgrading =y to =m
 
  - remove S_OTHER symbol type, and touch include/config/*.h files correctly
 
  - fix file name and line number in lexer warnings
 
  - fix memory leak when EOF is encountered in quotation
 
  - resolve all shift/reduce conflicts of the parser
 
  - warn no new line at end of file
 
  - make 'source' statement more strict to take only string literal
 
  - rewrite the lexer and remove the keyword lookup table
 
  - convert to SPDX License Identifier
 
  - compile C files independently instead of including them from zconf.y
 
  - fix various warnings of gconfig
 
  - misc cleanups
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJcJieuAAoJED2LAQed4NsGHlIP/1s0fQ86XD9dIMyHzAO0gh2f
 7rylfe2kEXJgIzJ0DyZdLu4iZtwbkEUqTQrRS1abriNGVemPkfBAnZdM5d92lOQX
 3iREa700AJ2xo7V7gYZ6AbhZoG3p0S9U9Q2qE5S+tFTe8c2Gy4xtjnODF+Vel85r
 S0P8tF5sE1/d00lm+yfMI/CJVfDjyNaMm+aVEnL0kZTPiRkaktjWgo6Fc2p4z1L5
 HFmMMP6/iaXmRZ+tHJGPQ2AT70GFVZw5ePxPcl50EotUP25KHbuUdzs8wDpYm3U/
 rcESVsIFpgqHWmTsdBk6dZk0q8yFZNkMlkaP/aYukVZpUn/N6oAXgTFckYl8dmQL
 fQBkQi6DTfr9EBPVbj18BKm7xI3Y4DdQ2fzTfYkJ2XwNRGFA5r9N3sjd7ZTVGjxC
 aeeMHCwvGdSx1x8PeZAhZfsUHW8xVDMSQiT713+ljBY+6cwzA+2NF0kP7B6OAqwr
 ETFzd4Xu2/lZcL7gQRH8WU3L2S5iedmDG6RnZgJMXI0/9V4qAA+nlsWaCgnl1TgA
 mpxYlLUMrd6AUJevE34FlnyFdk8IMn9iKRFsvF0f3doO5C7QzTVGqFdJu5a0CuWO
 4NBJvZjFT8/4amoWLfnDlfApWXzTfwLbKG+r6V2F30fLuXpYg5LxWhBoGRPYLZSq
 oi4xN1Mpx3TvXz6WcKVZ
 =r3Fl
 -----END PGP SIGNATURE-----

Merge tag 'kconfig-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kconfig updates from Masahiro Yamada:

 - support -y option for merge_config.sh to avoid downgrading =y to =m

 - remove S_OTHER symbol type, and touch include/config/*.h files correctly

 - fix file name and line number in lexer warnings

 - fix memory leak when EOF is encountered in quotation

 - resolve all shift/reduce conflicts of the parser

 - warn no new line at end of file

 - make 'source' statement more strict to take only string literal

 - rewrite the lexer and remove the keyword lookup table

 - convert to SPDX License Identifier

 - compile C files independently instead of including them from zconf.y

 - fix various warnings of gconfig

 - misc cleanups

* tag 'kconfig-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
  kconfig: surround dbg_sym_flags with #ifdef DEBUG to fix gconf warning
  kconfig: split images.c out of qconf.cc/gconf.c to fix gconf warnings
  kconfig: add static qualifiers to fix gconf warnings
  kconfig: split the lexer out of zconf.y
  kconfig: split some C files out of zconf.y
  kconfig: convert to SPDX License Identifier
  kconfig: remove keyword lookup table entirely
  kconfig: update current_pos in the second lexer
  kconfig: switch to ASSIGN_VAL state in the second lexer
  kconfig: stop associating kconf_id with yylval
  kconfig: refactor end token rules
  kconfig: stop supporting '.' and '/' in unquoted words
  treewide: surround Kconfig file paths with double quotes
  microblaze: surround string default in Kconfig with double quotes
  kconfig: use T_WORD instead of T_VARIABLE for variables
  kconfig: use specific tokens instead of T_ASSIGN for assignments
  kconfig: refactor scanning and parsing "option" properties
  kconfig: use distinct tokens for type and default properties
  kconfig: remove redundant token defines
  kconfig: rename depends_list to comment_option_list
  ...
2018-12-29 13:03:29 -08:00
Linus Torvalds c76cd634eb platform-drivers-x86 for v4.21-1
The USB Power Delivery discrete components now can be enumerated by
 i2c-multi-instantiate driver via several resources under single ACPI
 device node (ACPI ID is INT3515).
 
 Touchscreen support is added for the Mediacom Flexbook Edge 11.
 
 Mellanox driver got fixed due to updates in their firmware.
 
 The power management stub driver for AtomISP v2 is fixed in order to support
 Intel Baytrail SoCs where same quirk is needed for S0ix to work.
 
 Special key handling has been fixed for Favorites hotkey on Thinkpad, and
 Screen LOCK on ASUS.
 
 Ideapad Yoga 2 13 has no HW rfkill switch, thus, driver has been updated
 to support this.
 
 Few cleanups related to debugfs have been made in Intel IPS and
 Intel PMC drivers. Besides that Intel PMC has been extended
 to show more detailed information about Latency Tolerance.
 
 The following is an automated git shortlog grouped by driver:
 
 ACPI / scan:
  -  Create platform device for INT3515 ACPI nodes
 
 Add the VLV ISP PCI ID to atomisp2_pm:
  - Add the VLV ISP PCI ID to atomisp2_pm
 
 asus-nb-wmi:
  -  Drop mapping of 0x33 and 0x34 scan codes
  -  Map 0x35 to KEY_SCREENLOCK
 
 asus-wmi:
  -  Tell the EC the OS will handle the display off hotkey
 
 dell-laptop:
  -  Mark expected switch fall-throughs
 
 Documentation/ABI:
  -  Add new attribute for mlxreg-io sysfs interfaces
 
 Fix config space access for intel_atomisp2_pm:
  - Fix config space access for intel_atomisp2_pm
 
 i2c:
  -  acpi: Introduce i2c_acpi_get_i2c_resource() helper
  -  acpi: Use ACPI_FAILURE instead of !ACPI_SUCCESS
  -  acpi: Return error pointers from i2c_acpi_new_device()
 
 i2c-multi-instantiate:
  -  Allow to have same slaves
  -  Introduce IOAPIC IRQ support
  -  Distinguish IRQ resource type
  -  Count I2cSerialBus() resources
  -  Get rid of obsolete conditional
  -  Defer probe when no adapter found
  -  Accept errors of i2c_acpi_new_device()
 
 ideapad-laptop:
  -  Add Yoga 2 13 to no_hw_rfkill list
 
 iio:
  -  inv_mpu6050: Use i2c_acpi_get_i2c_resource() helper
 
 intel_cht_int33fe:
  -  Get rid of obsolete conditional
  -  Accept errors of i2c_acpi_new_device()
  -  Remove duplicate NULL check
 
 intel_ips:
  -  Convert to use DEFINE_SHOW_ATTRIBUTE macro
  -  Remove never happen condition
  -  NULL check before some freeing functions is not needed
  -  remove unnecessary checks in ips_debugfs_init
 
 intel_pmc_core:
  -  convert to DEFINE_SHOW_ATTRIBUTE
  -  Decode Snoop / Non Snoop LTR
  -  Fix LTR IGNORE Max offset
  -  Show Latency Tolerance info
 
 intel_telemetry:
  -  convert to DEFINE_SHOW_ATTRIBUTE
 
 mlx-platform:
  -  Convert to use SPDX identifier
  -  Allow mlxreg-io driver activation for new systems
  -  Fix LED configuration
  -  Fix tachometer registers
  -  Rename new systems product names
  -  Add definitions for new registers
 
 thinkpad_acpi:
  -  Cleanup quirks macros
  -  Change the keymap for Favorites hotkey
 
 touchscreen_dmi:
  -  Add info for the Mediacom Flexbook Edge 11
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEqaflIX74DDDzMJJtb7wzTHR8rCgFAlwRE+sACgkQb7wzTHR8
 rCi7URAAgpfdsHUkj3PdFmp5o3LHCD0m5Z9A6yAJrXyhCDRRkAMaGYyRe4vg3qE1
 GBA6MbMyOrtW/LqvaQAajeMmDINl1Mz/5OIVCIwJUPnKk8K7Yy93pH5vKecUPX8q
 ihItKmJIPdaqxH2LXrx6sh3Ob3QrVrcpfpW6109WM8auYB+BiNOhxejBZ4jvMiRd
 9dG657gx64Y6Ot5kjGKpdblFrA930sA5kAiMFiCcjNP9S7xLhgfyZiPMSP48gUWb
 OiqoJMsomamF8qxZsZzfRblZpOlFahuW51D2vZgHb7N6fA0qW1c3twdSoivQfTHa
 KA+OuMgJ52vI8JDgUKj55LB88Pn5iFtmDsNodgQ25cBLgBkzKJQU9MfoK8QafvlV
 OTjmGL+ENK4VufDwMEgOMlXdihVewOrQ3kzOm7JQgIlOSWE7l9BSa2CK0vSM9Jha
 nfjjc5LowJaWA+QUrmx29VrRGmSYfrGhquGV/3U+TPafc5blpiqWTGxIkhaNFhKx
 0yk/vzggGsIlvnYU2+zaJW8LAhLcb4R6ATEZMurZQdZlQefs+5oAEPSvOZ5gYdLX
 PWj3swTMkIp7FKjGm7532T83v5lJyO9cxSV/3aIqzkdWNqMoYDDuNU8wCzTTBv5m
 EoKQO+H2WCnlm5bgWQ82gjVDKmS63eDlT4WgYxm60OZ1ONuAwIo=
 =kYH6
 -----END PGP SIGNATURE-----

Merge tag 'platform-drivers-x86-v4.21-1' of git://git.infradead.org/linux-platform-drivers-x86

Pull x86 platform driver updates from Andy Shevchenko:

 - The USB Power Delivery discrete components now can be enumerated by
   i2c-multi-instantiate driver via several resources under single ACPI
   device node (ACPI ID is INT3515).

 - Touchscreen support is added for the Mediacom Flexbook Edge 11.

 - Mellanox driver got fixed due to updates in their firmware.

 - The power management stub driver for AtomISP v2 is fixed in order to
   support Intel Baytrail SoCs where same quirk is needed for S0ix to
   work.

 - Special key handling has been fixed for Favorites hotkey on Thinkpad,
   and Screen LOCK on ASUS.

 - Ideapad Yoga 2 13 has no HW rfkill switch, thus, driver has been
   updated to support this.

 - Few cleanups related to debugfs have been made in Intel IPS and Intel
   PMC drivers. Besides that Intel PMC has been extended to show more
   detailed information about Latency Tolerance

* tag 'platform-drivers-x86-v4.21-1' of git://git.infradead.org/linux-platform-drivers-x86: (41 commits)
  platform/x86: mlx-platform: Convert to use SPDX identifier
  Documentation/ABI: Add new attribute for mlxreg-io sysfs interfaces
  platform/x86: mlx-platform: Allow mlxreg-io driver activation for new systems
  platform/x86: mlx-platform: Fix LED configuration
  platform/x86: mlx-platform: Fix tachometer registers
  platform/x86: mlx-platform: Rename new systems product names
  platform/x86: mlx-platform: Add definitions for new registers
  platform/x86: intel_telemetry: convert to DEFINE_SHOW_ATTRIBUTE
  platform/x86: intel_pmc_core: convert to DEFINE_SHOW_ATTRIBUTE
  platform/x86: thinkpad_acpi: Cleanup quirks macros
  platform/x86: touchscreen_dmi: Add info for the Mediacom Flexbook Edge 11
  platform/x86: Fix config space access for intel_atomisp2_pm
  platform/x86: Add the VLV ISP PCI ID to atomisp2_pm
  platform/x86: intel_ips: Convert to use DEFINE_SHOW_ATTRIBUTE macro
  platform/x86: intel_ips: Remove never happen condition
  platform/x86: intel_ips: NULL check before some freeing functions is not needed
  platform/x86: intel_ips: remove unnecessary checks in ips_debugfs_init
  iio: inv_mpu6050: Use i2c_acpi_get_i2c_resource() helper
  ACPI / scan: Create platform device for INT3515 ACPI nodes
  platform/x86: i2c-multi-instantiate: Allow to have same slaves
  ...
2018-12-25 11:04:17 -08:00
Masahiro Yamada 8636a1f967 treewide: surround Kconfig file paths with double quotes
The Kconfig lexer supports special characters such as '.' and '/' in
the parameter context. In my understanding, the reason is just to
support bare file paths in the source statement.

I do not see a good reason to complicate Kconfig for the room of
ambiguity.

The majority of code already surrounds file paths with double quotes,
and it makes sense since file paths are constant string literals.

Make it treewide consistent now.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
2018-12-22 00:25:54 +09:00
Thierry Reding d6f0453391 i2c: tegra: Switch to SPDX identifier
Adopt the SPDX license identifier headers to ease license compliance
management.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-17 23:37:53 +01:00
Thierry Reding 0604ee4aef i2c: tegra: Add missing kerneldoc for some fields
Not all fields were properly documented. Add kerneldoc for the missing
fields to prevent the build from flagging them.

Reported-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-17 23:33:34 +01:00
Thierry Reding c990bbafdb i2c: tegra: Cleanup kerneldoc comments
Some of the kerneldoc uses a strange spelling for abbreviations. Turn
them into all-uppercase and clean up some whitespace issues while at it.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-17 23:32:44 +01:00
Adamski, Krzysztof (Nokia - PL/Wroclaw) 3035a66934 i2c: axxia: support sequence command mode
In order to comply with SMBus specification, the Axxia I²C module will
abort the multi message transfer if the delay between finishing sending
one message and starting another is longer than 25ms. Unfortunately it
isn't that hard to trigger this situation on a busy system. In order to
fix this problem, we should make sure hardware does whole transaction
without waiting for software to fill some data.

Fortunately, in addition to Manual mode that is currently used by the
driver to perform I²C transfers, the module supports also so called
Sequence mode. In this mode, the module automatically performs
predefined sequence of operations - it sends a slave address, transmits
specified number of bytes from the FIFO, changes transfer direction,
resends the slave address and then reads specified number of bytes to
FIFO. While very inflexible, this does fit a most common case of multi
message transfer - the one where you first write a register number you
want to read and then read it.

To use this mode effectively, a number of conditions must be met to
ensure the transaction does fit the predefined sequence. In case this is
not the case, a fallback to manual mode is used.

The initialization of this mode is very similar to Manual mode. The most
notable difference is different bit in the Master Interrupt Status
designating finishing of transaction. Also some of the errors, like TSS,
cannot happen in this mode.

While it is possible to support transactions requesting a read of any
size (RFL interrupt will be generated when FIFO size is not enough) the
TFL interrupt is not available in this mode, thus the write part of the
transaction cannot exceed FIFO_SIZE (8).

Note that in case of a NAK during transaction, the NA/ND status bits
will be set before STOP command is generated, triggering an interrupt
while the controller is still busy. Current solution for this problem is
to actively wait for this command to stop before leaving xfer callback.

Signed-off-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
[wsa: added braces around else branch spotted by checkpatch]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-17 23:28:50 +01:00
Fabrizio Castro 51243b7345 i2c: sh_mobile: Add support for r8a774c0 (RZ/G2E)
Similarly to R-Car E3, RZ/G2E doesn't come with automatic
transmission registers, as such it is not considered compatible
with the existing fallback bindings.

Add SoC specific binding compatibility to allow for later
support for automatic transmission.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-17 23:20:09 +01:00
Enric Balletbo i Serra 02d26b9a57 i2c: i2c-cros-ec-tunnel: Switch to SPDX identifier.
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>
2018-12-17 23:08:41 +01:00
Arnd Bergmann 32774a8153 i2c: nvidia-gpu: mark resume function as __maybe_unused
When CONFIG_PM is disabled, this is needed to avoid a harmless
unused-function warning:

drivers/i2c/busses/i2c-nvidia-gpu.c:345:12: error: 'gpu_i2c_resume' defined but not used [-Werror=unused-function]

Fixes: c71bcdcb42 ("i2c: add i2c bus driver for NVIDIA GPU")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-11 21:39:43 +01:00
Rob Herring 48f9c33c25 i2c: powermac: Use of_node_name_eq for node name comparisons
Convert string compares of DT node names to use of_node_name_eq helper
instead. This removes direct access to the node name pointer.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-11 21:16:28 +01:00
Adamski, Krzysztof (Nokia - PL/Wroclaw) 4f5c85fe3a i2c-axxia: check for error conditions first
It was observed that when using seqentional mode contrary to the
documentation, the SS bit (which is supposed to only be set if
automatic/sequence command completed normally), is sometimes set
together with NA (NAK in address phase) causing transfer to falsely be
considered successful.

My assumption is that this does not happen during manual mode since the
controller is stopping its work the moment it sets NA/ND bit in status
register. This is not the case in Automatic/Sequentional mode where it
is still working to send STOP condition and the actual status we get
depends on the time when the ISR is run.

This patch changes the order of checking status bits in ISR - error
conditions are checked first and only if none of them occurred, the
transfer may be considered successful. This is required to introduce
using of sequentional mode in next patch.

Signed-off-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-11 20:59:17 +01:00
Adamski, Krzysztof (Nokia - PL/Wroclaw) eb9907789a i2c-axxia: dedicated function to set client addr
This patch moves configuration of hardware registers used for setting
i2c client address to separate function. It is preparatory change for
next commit.

Signed-off-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-11 20:58:59 +01:00
Wolfram Sang 66693960f5 Linux 4.20-rc6
-----BEGIN PGP SIGNATURE-----
 
 iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAlwNpb0eHHRvcnZhbGRz
 QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGwGwH/00UHnXfxww3ixxz
 zwTVDzptA6SPm6s84yJOWatM5fXhPiAltZaHSYF9lzRzNU71NCq7Frhq3fQUIXKM
 OxqDn9nfSTWcjWTk2q5n2keyRV/KIn67YX7UgqFc1bO/mqtVjEgNWaMyblhI+e9E
 giu1ZXayHr43jK1cDOmGExZubXUq7Vsc9TOlrd+d2SwIqeEP7TCMrPhnHDwCNvX2
 UU5dtANpVzGtHaBcr37wJj+L8kODCc0f+PQ3g2ar5jTHst5SLlHp2u0AMRnUmgdi
 VkGx+mu/uk8mtwUqMIMqhplklVoqK6LTeLqsY5Xt32SKruw9UqyJGdphLjW2QP/g
 MkmA1lI=
 =7kaD
 -----END PGP SIGNATURE-----

Merge tag 'v4.20-rc6' into i2c/for-5.0

Linux 4.20-rc6
2018-12-11 20:58:20 +01:00
jun qian 3782cc3725 i2c: tegra: replace spin_lock_irqsave with spin_lock in ISR
As you are already in ISR, it is unnecessary to call spin_lock_irqsave.

Signed-off-by: jun qian <hangdianqj@163.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-11 20:56:52 +01:00
Masahiro Yamada ece27a337d i2c: uniphier-f: fix violation of tLOW requirement for Fast-mode
Currently, the clock duty is set as tLOW/tHIGH = 1/1. For Fast-mode,
tLOW is set to 1.25 us while the I2C spec requires tLOW >= 1.3 us.

tLOW/tHIGH = 5/4 would meet both Standard-mode and Fast-mode:
  Standard-mode: tLOW = 5.56 us, tHIGH = 4.44 us
  Fast-mode:     tLOW = 1.39 us, tHIGH = 1.11 us

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-06 23:14:59 +01:00
Masahiro Yamada 8469636ab5 i2c: uniphier: fix violation of tLOW requirement for Fast-mode
Currently, the clock duty is set as tLOW/tHIGH = 1/1. For Fast-mode,
tLOW is set to 1.25 us while the I2C spec requires tLOW >= 1.3 us.

tLOW/tHIGH = 5/4 would meet both Standard-mode and Fast-mode:
  Standard-mode: tLOW = 5.56 us, tHIGH = 4.44 us
  Fast-mode:     tLOW = 1.39 us, tHIGH = 1.11 us

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-06 23:14:59 +01:00
Masahiro Yamada cd8843f541 i2c: uniphier-f: fill TX-FIFO only in IRQ handler for repeated START
- For a repeated START condition, this controller starts data transfer
   immediately after the slave address is written to the TX-FIFO.

 - Once the TX-FIFO empty interrupt is asserted, the controller makes
   a pause even if additional data are written to the TX-FIFO.

Given those circumstances, the data after a repeated START may not be
transferred if the interrupt is asserted while the TX-FIFO is being
filled up. A more reliable way is to append TX data only in the
interrupt handler.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-06 23:14:59 +01:00
Masahiro Yamada c2a653deaa i2c: uniphier-f: fix timeout error after reading 8 bytes
I was totally screwed up in commit eaba68785c ("i2c: uniphier-f:
fix race condition when IRQ is cleared"). Since that commit, if the
number of read bytes is multiple of the FIFO size (8, 16, 24... bytes),
the STOP condition could be issued twice, depending on the timing.
If this happens, the controller will go wrong, resulting in the timeout
error.

It was more than 3 years ago when I wrote this driver, so my memory
about this hardware was vague. Please let me correct the description
in the commit log of eaba68785c.

Clearing the IRQ status on exiting the IRQ handler is absolutely
fine. This controller makes a pause while any IRQ status is asserted.
If the IRQ status is cleared first, the hardware may start the next
transaction before the IRQ handler finishes what it supposed to do.

This partially reverts the bad commit with clear comments so that I
will never repeat this mistake.

I also investigated what is happening at the last moment of the read
mode. The UNIPHIER_FI2C_INT_RF interrupt is asserted a bit earlier
(by half a period of the clock cycle) than UNIPHIER_FI2C_INT_RB.

I consulted a hardware engineer, and I got the following information:

UNIPHIER_FI2C_INT_RF
    asserted at the falling edge of SCL at the 8th bit.

UNIPHIER_FI2C_INT_RB
    asserted at the rising edge of SCL at the 9th (ACK) bit.

In order to avoid calling uniphier_fi2c_stop() twice, check the latter
interrupt. I also commented this because it is obscure hardware internal.

Fixes: eaba68785c ("i2c: uniphier-f: fix race condition when IRQ is cleared")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-06 23:14:59 +01:00
Hans de Goede 0544ee4b1a i2c: scmi: Fix probe error on devices with an empty SMB0001 ACPI device node
Some AMD based HP laptops have a SMB0001 ACPI device node which does not
define any methods.

This leads to the following error in dmesg:

[    5.222731] cmi: probe of SMB0001:00 failed with error -5

This commit makes acpi_smbus_cmi_add() return -ENODEV instead in this case
silencing the error. In case of a failure of the i2c_add_adapter() call
this commit now propagates the error from that call instead of -EIO.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-06 23:14:59 +01:00
Adamski, Krzysztof (Nokia - PL/Wroclaw) 6c7f25cae5 i2c: axxia: properly handle master timeout
According to Intel (R) Axxia TM Lionfish Communication Processor
Peripheral Subsystem Hardware Reference Manual, the AXXIA I2C module
have a programmable Master Wait Timer, which among others, checks the
time between commands send in manual mode. When a timeout (25ms) passes,
TSS bit is set in Master Interrupt Status register and a Stop command is
issued by the hardware.

The axxia_i2c_xfer(), does not properly handle this situation, however.
For each message a separate axxia_i2c_xfer_msg() is called and this
function incorrectly assumes that any interrupt might happen only when
waiting for completion. This is mostly correct but there is one
exception - a master timeout can trigger if enough time has passed
between individual transfers. It will, by definition, happen between
transfers when the interrupts are disabled by the code. If that happens,
the hardware issues Stop command.

The interrupt indicating timeout will not be triggered as soon as we
enable them since the Master Interrupt Status is cleared when master
mode is entered again (which happens before enabling irqs) meaning this
error is lost and the transfer is continued even though the Stop was
issued on the bus. The subsequent operations completes without error but
a bogus value (0xFF in case of read) is read as the client device is
confused because aborted transfer. No error is returned from
master_xfer() making caller believe that a valid value was read.

To fix the problem, the TSS bit (indicating timeout) in Master Interrupt
Status register is checked before each transfer. If it is set, there was
a timeout before this transfer and (as described above) the hardware
already issued Stop command so the transaction should be aborted thus
-ETIMEOUT is returned from the master_xfer() callback. In order to be
sure no timeout was issued we can't just read the status just before
starting new transaction as there will always be a small window of time
(few CPU cycles at best) where this might still happen. For this reason
we have to temporally disable the timer before checking for TSS bit.
Disabling it will, however, clear the TSS bit so in order to preserve
that information, we have to read it in ISR so we have to ensure that
the TSS interrupt is not masked between transfers of one transaction.
There is no need to call bus recovery or controller reinitialization if
that happens so it's skipped.

Signed-off-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-06 23:14:53 +01:00
Andy Shevchenko 0d5102fe85 i2c: acpi: Introduce i2c_acpi_get_i2c_resource() helper
Besides current two users one more is coming. Definitely makes sense to
introduce a helper.

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-03 21:40:02 +02:00
Andy Shevchenko 5f59d6a110 i2c: acpi: Use ACPI_FAILURE instead of !ACPI_SUCCESS
Convert to use ACPI_FAILURE instead of !ACPI_SUCCESS.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-03 21:40:02 +02:00
Andy Shevchenko 2dea645ffc i2c: acpi: Return error pointers from i2c_acpi_new_device()
The caller would like to know the reason why the i2c_acpi_new_device() fails.
For example, if adapter is not available, it might be in the future and we
would like to re-probe the clients again. But at the same time we would like to
bail out if the error seems unrecoverable, such as invalid argument supplied.
To achieve this, return error pointer in some cases.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-03 21:40:02 +02:00
Pierre-Yves MORDRET 4e7bca6fc0 i2c: i2c-stm32f7: add PM Runtime support
Use PM Runtime API to enable/disable clock

Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-01 00:14:45 +01:00
Wolfram Sang 0b57436f15 i2c: rcar: check bus state before reinitializing
We should check the bus state before reinitializing the IP core.
Otherwise, the internal bus busy state which also tracks multi-master
activity is lost.

Credits go to the Renesas BSP team for suggesting this change.

Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Fixes: ae481cc139 ("i2c: rcar: fix resume by always initializing registers before transfer")
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-11-27 14:00:36 +01:00
Wolfram Sang 39129f28c9 i2c: nvidia-gpu: limit reads also for combined messages
If the controller can only do 4 byte reads, this needs to be applied for
the read-part of combined messages, too.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fixes: c71bcdcb42 ("i2c: add i2c bus driver for NVIDIA GPU")
Acked-by: Ajay Gupta <ajayg@nvidia.com>
Tested-by: Ajay Gupta <ajayg@nvidia.com>
2018-11-27 14:00:22 +01:00
Wolfram Sang 98be694ba2 i2c: nvidia-gpu: adhere to I2C fault codes
As described in Documentation/i2c/fault-codes.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fixes: c71bcdcb42 ("i2c: add i2c bus driver for NVIDIA GPU")
Acked-by: Ajay Gupta <ajayg@nvidia.com>
Tested-by: Ajay Gupta <ajayg@nvidia.com>
2018-11-27 13:59:10 +01:00
Simon Horman 5eb316e636 i2c: sh_mobile: add support for r8a77990 (R-Car E3)
Add support for the IIC code for the r8a77990 (R-Car E3).

It is not considered compatible with existing fallback bindings
due to the documented absence of automatic transmission registers.

These registers are currently not used by the driver and
thus the provides the same behaviour for "renesas,iic-r8a77990" and
"renesas,rcar-gen3-iic". The point of declaring incompatibility is
to allow for automatic transmission register support to be added to
"renesas,iic-r8a77990" and "renesas,rcar-gen3-iic" in future.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-11-27 13:30:01 +01:00
Pierre-Yves MORDRET cb944fb973 i2c: stm32f7: SYSCFG Fast Mode Plus support for I2C STM32F7
Read SYSCFG bindings to set Fast Mode Plus bits if Fast Mode Plus
speed is selected.

Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-11-27 13:08:17 +01:00
Davidlohr Bueso e79ba3b550 i2c: Remove caller signal_pending branch predictions
This is already done for us internally by the signal machinery.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-11-27 12:59:16 +01:00
Lucas Stach fece497851 i2c: imx: don't print error message on probe defer
Probe deferral is a normal operating condition in the probe function,
so don't spam the log with an error in this case.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-11-27 12:55:45 +01:00
Stefan Wahren 346f7e6b7b i2c: bcm2835: Switch to SPDX identifier
Adopt the SPDX license identifier headers to ease license compliance
management.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-11-27 12:50:07 +01:00
Wolfram Sang caccdcc5db i2c: nvidia-gpu: make pm_ops static
sparse rightfully says:

warning: symbol 'gpu_i2c_driver_pm' was not declared. Should it be static?

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-11-09 17:56:44 +01:00
Ajay Gupta c71bcdcb42 i2c: add i2c bus driver for NVIDIA GPU
Latest NVIDIA GPU card has USB Type-C interface. There is a
Type-C controller which can be accessed over I2C.

This driver adds I2C bus driver to communicate with Type-C controller.
I2C client driver will be part of USB Type-C UCSI driver.

Signed-off-by: Ajay Gupta <ajayg@nvidia.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[wsa: kept Makefile sorting]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-11-09 17:46:43 +01:00
Stephen Boyd 848bd3f3de i2c: qcom-geni: Fix runtime PM mismatch with child devices
We need to enable runtime PM on this i2c controller before populating
child devices with i2c_add_adapter(). Otherwise, if a child device uses
runtime PM and stays runtime PM enabled we'll get the following warning
at boot.

 Enabling runtime PM for inactive device (a98000.i2c) with active children

[...]

 Call trace:
  pm_runtime_enable+0xd8/0xf8
  geni_i2c_probe+0x440/0x460
  platform_drv_probe+0x74/0xc8
[...]

Let's move the runtime PM enabling and setup to before we add the
adapter, so that this device can respond to runtime PM requests from
children.

Fixes: 37692de5d5 ("i2c: i2c-qcom-geni: Add bus driver for the Qualcomm GENI I2C controller")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-11-09 17:25:48 +01:00
Vignesh R 5b277402de i2c: omap: Enable for ARCH_K3
Allow I2C_OMAP to be built for K3 platforms.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-11-09 17:25:29 +01:00
Charles Keepax 6f108dd70d i2c: Clear client->irq in i2c_device_remove
The IRQ will be mapped in i2c_device_probe only if client->irq is zero and
i2c_device_remove does not clear this. When rebinding an I2C device,
whos IRQ provider has also been rebound this means that an IRQ mapping
will never be created, causing the I2C device to fail to acquire its
IRQ. Fix this issue by clearing client->irq in i2c_device_remove,
forcing i2c_device_probe to lookup the mapping again.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-10-31 23:33:34 +00:00
Charles Keepax b9bb3fdf4e i2c: Remove unnecessary call to irq_find_mapping
irq_create_mapping calls irq_find_mapping internally and will use the
found mapping if one exists, so there is no need to manually call this
from i2c_smbus_host_notify_to_irq.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-10-31 23:33:14 +00:00
Linus Torvalds c2101d0182 More ACPI updates for 4.20-rc1
Rework the handling of the P-unit semaphore on Intel Baytrail and
 Cherrytrail systems to avoid race conditions and excessive overhead
 related to it (Hans de Goede).
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABCAAGBQJb2BIsAAoJEILEb/54YlRx/3IP/jhBujlb884Yz1Kzix2cEat0
 56fqh1TJTn9ZyOQjTW2rIbRnOdSNHzerLWWoUZdKO9ndO1gRvLgNBILug2zC/9TZ
 gZ+AODC7JVcAvSk8vVCN7wtHbDFH23dEP5kdye8Ax4MqMFY0ctKMVIvicPD7HXFS
 nFaB/JZQ9SlWKmaIPQKpyTQ5dCTZM5qnziYiRt56HpEFoCPYdzaaUx7zlVWJff8J
 N521n3bEgxglOBqJyGkR5LvOZJ7S92KwOL94FNCY0/yEDbY53YWTxXkpFJVbBzlK
 gELAehxUBD9cnwi+g1OSrTCeOVdsCWwmiztTbpHlcLhCITsHFdg1B6SPlX3Sw4Wv
 DRszpnazSJfJj87JNRaYBXdgQnDs3wDW5yji3aTbu8MOa8kWMrpDzmR/qs4vYZGT
 EB37hKk0ZO15dNeIhHmKoo4d3pzDYzSAeJ1d1c2cOG5QMF3qsIfZyHyDQAUaIYMx
 EkLhZki2PyOFicgTlchr+9mBsXT37KrJXxYIFb4w2BjzZ4u74IEER4QDgRHSFuTL
 sJgxrqY/+n1142UqFRhgu59yeRKl+seyNHB/RptM1DsVs4BRkHcEj4pfBPq49Kxv
 2H0ByTAvy09olcFvFqSVCFzPEquNsLJrvhrTiwbduOsBcVHwXIWNywaBwjeYllPX
 iNIWx7Nr/TzlV4hPO8pH
 =4oYh
 -----END PGP SIGNATURE-----

Merge tag 'acpi-4.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more ACPI updates from Rafael Wysocki:
 "Rework the handling of the P-unit semaphore on Intel Baytrail and
  Cherrytrail systems to avoid race conditions and excessive overhead
  related to it (Hans de Goede)"

* tag 'acpi-4.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / PMIC: xpower: Add depends on IOSF_MBI to Kconfig entry
  i2c: designware: Cleanup bus lock handling
  ACPI / PMIC: xpower: Block P-Unit I2C access during read-modify-write
  x86: baytrail/cherrytrail: Rework and move P-Unit PMIC bus semaphore code
2018-10-30 09:15:31 -07:00
Linus Torvalds 57dbde63f2 Merge branch 'i2c/for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
 "I2C has not so much stuff this time. Mostly driver enablement for new
  SoCs, some driver bugfixes, and some cleanups"

* 'i2c/for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (35 commits)
  MAINTAINERS: add maintainer for Renesas RIIC driver
  i2c: sh_mobile: Remove dummy runtime PM callbacks
  i2c: uniphier-f: fix race condition when IRQ is cleared
  i2c: uniphier-f: fix occasional timeout error
  i2c: uniphier-f: make driver robust against concurrency
  i2c: i2c-qcom-geni: Simplify irq handler
  i2c: i2c-qcom-geni: Simplify tx/rx functions
  i2c: designware: Set IRQF_NO_SUSPEND flag for all BYT and CHT controllers
  i2c: mux: mlxcpld: simplify code to reach the adapter
  i2c: mux: ltc4306: simplify code to reach the adapter
  i2c: mux: pca954x: simplify code to reach the adapter
  i2c: core: remove level of indentation in i2c_transfer
  i2c: core: remove outdated DEBUG output
  i2c: zx2967: use core to detect 'no zero length' quirk
  i2c: tegra: use core to detect 'no zero length' quirk
  i2c: qup: use core to detect 'no zero length' quirk
  i2c: omap: use core to detect 'no zero length' quirk
  i2c: Convert to using %pOFn instead of device_node.name
  i2c: brcmstb: Allow enabling the driver on DSL SoCs
  eeprom: at24: fix unexpected timeout under high load
  ...
2018-10-29 14:44:03 -07:00
Jarkko Nikula 7ce6c65b61 i2c: sh_mobile: Remove dummy runtime PM callbacks
Platform drivers don't need dummy runtime PM callbacks that just return
success and non-NULL pm pointer in their struct device_driver in order
to have runtime PM happening. This has changed since following commits:

05aa55dddb ("PM / Runtime: Lenient generic runtime pm callbacks")
543f2503a9 ("PM / platform_bus: Allow runtime PM by default")
8b313a38ec ("PM / Platform: Use generic runtime PM callbacks directly")

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-10-29 18:53:38 +00:00
Masahiro Yamada eaba68785c i2c: uniphier-f: fix race condition when IRQ is cleared
The current IRQ handler clears all the IRQ status bits when it bails
out. This is dangerous because it might clear away the status bits
that have just been set while processing the current handler. If this
happens, the IRQ event for the latest transfer is lost forever.

The IRQ status bits must be cleared *before* the next transfer is
kicked.

Fixes: 6a62974b66 ("i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-10-29 18:53:37 +00:00
Masahiro Yamada 39226aaa85 i2c: uniphier-f: fix occasional timeout error
Currently, a timeout error could happen at a repeated START condition.

For a (non-repeated) START condition, the controller starts sending
data when the UNIPHIER_FI2C_CR_STA bit is set. However, for a repeated
START condition, the hardware starts running when the slave address is
written to the TX FIFO - the write to the UNIPHIER_FI2C_CR register is
actually unneeded.

Because the hardware is already running before the IRQ is enabled for
a repeated START, the driver may miss the IRQ event. In most cases,
this problem does not show up since modern CPUs are much faster than
the I2C transfer. However, it is still possible that a context switch
happens after the controller starts, but before the IRQ register is
set up.

To fix this,

 - Do not write UNIPHIER_FI2C_CR for repeated START conditions.

 - Enable IRQ *before* writing the slave address to the TX FIFO.

 - Disable IRQ for the current CPU while queuing up the TX FIFO;
   If the CPU is interrupted by some task, the interrupt handler
   might be invoked due to the empty TX FIFO before completing the
   setup.

Fixes: 6a62974b66 ("i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-10-29 18:53:37 +00:00
Masahiro Yamada f1fdcbbdf4 i2c: uniphier-f: make driver robust against concurrency
This is unlikely to happen, but it is possible for a CPU to enter
the interrupt handler just after wait_for_completion_timeout() has
expired. If this happens, the hardware is accessed from multiple
contexts concurrently.

Disable the IRQ after wait_for_completion_timeout(), and do nothing
from the handler when the IRQ is disabled.

Fixes: 6a62974b66 ("i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-10-29 18:53:37 +00:00