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path: root/drivers/i2c/busses/i2c-cadence.c
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2015-01-14i2c: cadence: Check for errata condition involving master receiveHarini Katakam1-0/+14
Cadence I2C controller has the following bugs: - completion indication is not given to the driver at the end of a read/receive transfer with HOLD bit set. - Invalid read transaction are generated on the bus when HW timeout condition occurs with HOLD bit set. As a result of the above, if a set of messages to be transferred with repeated start includes any message following a read message, completion is never indicated and timeout occurs. Hence a check is implemented to return -EOPNOTSUPP for such sequences. Signed-off-by: Harini Katakam <harinik@xilinx.com> Signed-off-by: Vishnu Motghare <vishnum@xilinx.com> [wsa: fixed some whitespaces] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-01-13i2c: cadence: Handle > 252 byte transfersHarini Katakam1-73/+102
The I2C controller sends a NACK to the slave when transfer size register reaches zero, irrespective of the hold bit. So, in order to handle transfers greater than 252 bytes, the transfer size register has to be maintained at a value >= 1. This patch implements the same. The interrupt status is cleared at the beginning of the isr instead of the end, to avoid missing any interrupts. Signed-off-by: Harini Katakam <harinik@xilinx.com> [wsa: added braces around else branch] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-12-15Merge tag 'driver-core-3.19-rc1' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core update from Greg KH: "Here's the set of driver core patches for 3.19-rc1. They are dominated by the removal of the .owner field in platform drivers. They touch a lot of files, but they are "simple" changes, just removing a line in a structure. Other than that, a few minor driver core and debugfs changes. There are some ath9k patches coming in through this tree that have been acked by the wireless maintainers as they relied on the debugfs changes. Everything has been in linux-next for a while" * tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits) Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries" fs: debugfs: add forward declaration for struct device type firmware class: Deletion of an unnecessary check before the function call "vunmap" firmware loader: fix hung task warning dump devcoredump: provide a one-way disable function device: Add dev_<level>_once variants ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries ath: use seq_file api for ath9k debugfs files debugfs: add helper function to create device related seq_file drivers/base: cacheinfo: remove noisy error boot message Revert "core: platform: add warning if driver has no owner" drivers: base: support cpu cache information interface to userspace via sysfs drivers: base: add cpu_device_create to support per-cpu devices topology: replace custom attribute macros with standard DEVICE_ATTR* cpumask: factor out show_cpumap into separate helper function driver core: Fix unbalanced device reference in drivers_probe driver core: fix race with userland in device_add() sysfs/kernfs: make read requests on pre-alloc files use the buffer. sysfs/kernfs: allow attributes to request write buffer be pre-allocated. fs: sysfs: return EGBIG on write if offset is larger than file size ...
2014-12-04i2c: cadence: Set the hardware time-out register to maximum valueVishnu Motghare1-0/+11
Cadence I2C controller has bug wherein it generates invalid read transactions after timeout in master receiver mode. This driver does not use the HW timeout and this interrupt is disabled but the feature itself cannot be disabled. Hence, this patch writes the maximum value (0xFF) to this register. This is one of the workarounds to this bug and it will not avoid the issue completely but reduces the chances of error. Signed-off-by: Vishnu Motghare <vishnum@xilinx.com> Signed-off-by: Harini Katakam <harinik@xilinx.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
2014-10-20i2c: busses: drop owner assignment from platform_driversWolfram Sang1-1/+0
A platform_driver does not need to set an owner, it will be populated by the driver core. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-04-06i2c: Add driver for Cadence I2C controllerSoren Brinkmann1-0/+905
Add a driver for the Cadence I2C controller. This controller is for example found in Xilinx Zynq. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Tested-by: Michal Simek <michal.simek@xilinx.com> Reviewed-by: Harini Katakam <harinik@xilinx.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>