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path: root/drivers/char/hw_random/timeriomem-rng.c
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2017-06-01hw_random: timeriomem_rng: Allow setting RNG quality from platform dataRick Altherr1-0/+7
When a hw_random device's quality is non-zero, it will automatically be used to fill the kernel's entropy pool. Since timeriomem_rng is used by many different devices, the quality needs to be provided by platform data or device tree. Signed-off-by: Rick Altherr <raltherr@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-04-10hwrng: timeriomem - Improve performance for sub-jiffie update periodsRick Altherr1-41/+45
Some hardware RNGs provide a single register for obtaining random data. Instead of signaling when new data is available, the reader must wait a fixed amount of time between reads for new data to be generated. timeriomem_rng implements this scheme with the period specified in platform data or device tree. While the period is specified in microseconds, the implementation used a standard timer which has a minimum delay of 1 jiffie and caused a significant bottleneck for devices that can update at 1us. By switching to an hrtimer, 1us periods now only delay at most 2us per read. Signed-off-by: Rick Altherr <raltherr@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-04-10hwrng: timeriomem - Shorten verbose type and variable namesRick Altherr1-14/+13
No functional changes. Signed-off-by: Rick Altherr <raltherr@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-04-10hwrng: timeriomem - Migrate to new APIRick Altherr1-30/+30
Preserves the existing behavior of only returning 32-bits per call. Signed-off-by: Rick Altherr <raltherr@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-10-20char: hw_random: 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>
2014-05-08hwrng: timeriomem - remove unnecessary OOM messagesJingoo Han1-3/+1
The site-specific OOM messages are unnecessary, because they duplicate the MM subsystem generic OOM message. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2014-03-10hwrng: timeriomem - Use devm_*() functionsJingoo Han1-30/+10
Use devm_*() functions to make cleanup paths simpler. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2013-11-15tree-wide: use reinit_completion instead of INIT_COMPLETIONWolfram Sang1-1/+1
Use this new function to make code more comprehensible, since we are reinitialzing the completion, not initializing. [akpm@linux-foundation.org: linux-next resyncs] Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13) Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-24hwrng: timeriomem - remove unnecessary platform_set_drvdata()Jingoo Han1-2/+0
The driver core clears the driver data to NULL after device_release or on probe failure, since commit 0998d0631001288a5974afc0b2a5f568bcdecb4d (device-core: Ensure drvdata = NULL when no driver is bound). Thus, it is not needed to manually clear the device driver data to NULL. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2013-04-25hwrng: timeriomem - added devicetree hooksAlexander Clouter1-2/+22
This patch allows timeriomem_rng to be used via devicetree. Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2013-04-25hwrng: timeriomem - update to support more than one deviceAlexander Clouter1-54/+116
timeriomem_rng only supports a single device instance. This patch enables multiple timeriomem_rng devices to coexist as well as adds some additional error checking. Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2013-01-04Drivers: char: remove __dev* attributes.Greg Kroah-Hartman1-2/+2
CONFIG_HOTPLUG is going away as an option. As a result, the __dev* markings need to be removed. This change removes the use of __devinit, __devexit_p, __devinitdata, __devinitconst, and __devexit from these drivers. Based on patches originally written by Bill Pemberton, but redone by me in order to handle some of the coding style issues better, by hand. Cc: Bill Pemberton <wfp5p@virginia.edu> Cc: David Airlie <airlied@linux.ie> Cc: Matt Mackall <mpm@selenic.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-22char: remove use of __devexitBill Pemberton1-1/+1
CONFIG_HOTPLUG is going away as an option so __devexit is no longer needed. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Cc: David Airlie <airlied@linux.ie> Cc: Olof Johansson <olof@lixom.net> Cc: Mattia Dongili <malattia@linux.it> Cc: Kent Yoder <key@linux.vnet.ibm.com> Cc: Rajiv Andrade <mail@srajiv.net> Cc: Marcel Selhorst <tpmdd@selhorst.net> Cc: Sirrix AG <tpmdd@sirrix.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-arm-kernel@lists.infradead.org Cc: openipmi-developer@lists.sourceforge.net Cc: platform-driver-x86@vger.kernel.org Cc: tpmdd-devel@lists.sourceforge.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2011-11-30char: hw_random: convert drivers/char/hw_random/* to use ↵Axel Lin1-12/+1
module_platform_driver() This patch converts the drivers in drivers/char/hw_random/* to use the module_platform_driver() macro which makes the code smaller and a bit simpler. Cc: David S. Miller <davem@davemloft.net> Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Axel Lin <axel.lin@gmail.com> Acked-by: Jamie Iles <jamie@jamieiles.com> Acked-by: Alexander Clouter <alex@digriz.org.uk> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: David Daney <david.daney@cavium.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2011-06-30hwrng: timeriomem - use resource_sizeH Hartley Sweeten1-2/+1
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-06-03hwrng: timeriomem - Fix potential oops (request_mem_region/__devinit)Alexander Clouter1-20/+6
Fixed oops when calling device_unregister followed by device_register (changing __init to __devinit) and removed request_mem_region() as platform_device_register already does this which can result in EBUSY Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-03-27hwrng: timeriomem - Use phys address rather than virtAlexander Clouter1-4/+35
There is no ioremap'ing or anything in timeriomem-rng.c as I foolishly used already remapped virtual addresses instead of passing the physical address to be polled. This patch fixes this flaw and lets developers do the Right Thing(tm). Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-02-22hwrng: timeriomem - New driverAlexander Clouter1-0/+151
Some hardware platforms, the TS-7800[1] is one for example, can supply the kernel with an entropy source, albeit a slow one for TS-7800 users, by just reading a particular IO address. This source must not be read above a certain rate otherwise the quality suffers. The driver is then hooked into by calling platform_device_(register|add|del) passing a structure similar to: ------ static struct timeriomem_rng_data ts78xx_ts_rng_data = { .address = (u32 *__iomem) TS_RNG, .period = 1000000, /* one second */ }; static struct platform_device ts78xx_ts_rng_device = { .name = "timeriomem_rng", .id = -1, .dev = { .platform_data = &ts78xx_ts_rng_data, }, .num_resources = 0, }; ------ [1] http://www.embeddedarm.com/products/board-detail.php?product=TS-7800 Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>