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path: root/drivers/nvmem/core.c
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2017-06-09nvmem: core: add locking to nvmem_find_cellHeiner Kallweit
Adding entries to nvmem_cells and deleting entries from it is protected by nvmem_cells_mutex. Therefore this mutex should also protect iterating over the list. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09nvmem: core: Call put_device() in nvmem_unregister()Andrey Smirnov
Call put_device() in nvmem_unregister() to make sure nvmem_release gets called freeing up allocated resources. Cc: cphealy@gmail.com Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Cc: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09nvmem: core: fix leaks on registration errorsJohan Hovold
Make sure to deregister and release the nvmem device and underlying memory on registration errors. Note that the private data must be freed using put_device() once the struct device has been initialised. Also note that there's a related reference leak in the deregistration function as reported by Mika Westerberg which is being fixed separately. Fixes: b6c217ab9be6 ("nvmem: Add backwards compatibility support for older EEPROM drivers.") Fixes: eace75cfdcf7 ("nvmem: Add a simple NVMEM framework for nvmem providers") Cc: stable <stable@vger.kernel.org> # 4.3 Cc: Andrew Lunn <andrew@lunn.ch> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Johan Hovold <johan@kernel.org> Acked-by: Andrey Smirnov <andrew.smirnov@gmail.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08nvmem: core: Allow allocating several anonymous nvmem devicesAban Bedel
Currently the nvmem core expect the config to provide a name and ID that are then used to create the device name. When no device name is given 'nvmem' is used. However if there is several such anonymous devices they all get named 'nvmem0', which doesn't work. To fix this problem use the ID from the config only when the config also provides a name. When no name is provided take the uinque ID of the nvmem device instead. Signed-off-by: Aban Bedel <albeu@free.fr> Reviewed-by: Moritz Fischer <mdf@kernel.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25nvmem: core: Allow getting nvmem cell with a NULL cell idVivek Gautam
The nvmem cell with a NULL cell name/id should be the one with no accompanying 'nvmem-cell-names' property, and thus will be the cell at index 0 in the device tree. So, we default to index 0 and update the cell index only when nvmem cell name id exists. Suggested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25nvmem: core: Correct a bunch of function documentationsVivek Gautam
Correct the documentation for arguments to a number of functions. Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25nvmem: core: Allow ignoring length when reading a cellVivek Gautam
nvmem_cell_read() API fills in the argument 'len' with the number of bytes read from the cell. Many users don't care about this length value. So allow users to pass a NULL pointer to this len field. Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-04nvmem: fix nvmem_cell_read() return type docBrian Norris
nvmem_cell_read() returns void *, not char *. This is a cleanup that got left out of commit a6c50912508d ("nvmem: Declare nvmem_cell_read() consistently"). Signed-off-by: Brian Norris <briannorris@chromium.org> Fixes: a6c50912508d ("nvmem: Declare nvmem_cell_read() consistently") Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-27remove lots of IS_ERR_VALUE abusesArnd Bergmann
Most users of IS_ERR_VALUE() in the kernel are wrong, as they pass an 'int' into a function that takes an 'unsigned long' argument. This happens to work because the type is sign-extended on 64-bit architectures before it gets converted into an unsigned type. However, anything that passes an 'unsigned short' or 'unsigned int' argument into IS_ERR_VALUE() is guaranteed to be broken, as are 8-bit integers and types that are wider than 'unsigned long'. Andrzej Hajda has already fixed a lot of the worst abusers that were causing actual bugs, but it would be nice to prevent any users that are not passing 'unsigned long' arguments. This patch changes all users of IS_ERR_VALUE() that I could find on 32-bit ARM randconfig builds and x86 allmodconfig. For the moment, this doesn't change the definition of IS_ERR_VALUE() because there are probably still architecture specific users elsewhere. Almost all the warnings I got are for files that are better off using 'if (err)' or 'if (err < 0)'. The only legitimate user I could find that we get a warning for is the (32-bit only) freescale fman driver, so I did not remove the IS_ERR_VALUE() there but changed the type to 'unsigned long'. For 9pfs, I just worked around one user whose calling conventions are so obscure that I did not dare change the behavior. I was using this definition for testing: #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \ unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO)) which ends up making all 16-bit or wider types work correctly with the most plausible interpretation of what IS_ERR_VALUE() was supposed to return according to its users, but also causes a compile-time warning for any users that do not pass an 'unsigned long' argument. I suggested this approach earlier this year, but back then we ended up deciding to just fix the users that are obviously broken. After the initial warning that caused me to get involved in the discussion (fs/gfs2/dir.c) showed up again in the mainline kernel, Linus asked me to send the whole thing again. [ Updated the 9p parts as per Al Viro - Linus ] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Andrzej Hajda <a.hajda@samsung.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.org/lkml/2016/1/7/363 Link: https://lkml.org/lkml/2016/5/27/486 Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-01nvmem: core: remove regmap dependencySrinivas Kandagatla
nvmem uses regmap_raw_read/write apis to read/write data from providers, regmap raw apis stopped working with recent kernels which removed raw accessors on mmio bus. This resulted in broken nvmem for providers which are based on regmap mmio bus. This issue can be fixed temporarly by moving to other regmap apis, but we might hit same issue in future. Moving to interfaces based on read/write callbacks from providers would be more robust. This patch removes regmap dependency from nvmem and introduces read/write callbacks from the providers. Without this patch nvmem providers like qfprom based on regmap mmio bus would not work. Reported-by: Rajendra Nayak <rjendra@qti.qualcomm.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01nvmem: Add backwards compatibility support for older EEPROM drivers.Andrew Lunn
Older drivers made an 'eeprom' file available in the /sys device directory. Have the NVMEM core provide this to retain backwards compatibility. Signed-off-by: Andrew Lunn <andrew@lunn.ch> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01nvmem: Add flag to export NVMEM to root onlyAndrew Lunn
Legacy AT24, AT25 EEPROMs are exported in sys so that only root can read the contents. The EEPROMs may contain sensitive information. Add a flag so the provide can indicate that NVMEM should also restrict access to root only. Signed-off-by: Andrew Lunn <andrew@lunn.ch> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-11nvmem: core: fix error path in nvmem_add_cells()Rasmus Villemoes
The current code fails to nvmem_cell_drop(cells[0]) - even worse, if the loop above fails already at i==0, we'll enter an essentially infinite loop doing nvmem_cell_drop on cells[-1], cells[-2], ... which is unlikely to end well. Also, we're not freeing the temporary backing array cells on the error path. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07nvmem: core: return error for non word aligned accessSrinivas Kandagatla
nvmem providers have restrictions on register strides, so return error when users attempt to read/write buffers with sizes which are less than word size. Without this patch the userspace would continue to try as it does not get any error from the nvmem core, resulting in a hang or endless loop in userspace. Reported-by: Ariel D'Alessandro <ariel@vanguardiasur.com.ar> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04nvmem: core: Fix memory leak in nvmem_cell_writeAxel Lin
A tmp buffer is allocated if cell->bit_offset || cell->nbits. So the tmp buffer needs to be freed at the same condition to avoid leak. Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04nvmem: core: Handle shift bits in-place if cell->nbits is non-zeroAxel Lin
It's pointless to test (cell->bit_offset || cell->bit_offset). nvmem_shift_read_buffer_in_place() should be called when (cell->bit_offset || cell->nbits). Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04nvmem: core: fix the out-of-range leak in read/write()ZhengShunQian
The position to read/write must be less than max register size. Signed-off-by: ZhengShunQian <zhengsq@rock-chips.com> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05nvmem: Add nvmem_device based consumer apis.Srinivas Kandagatla
This patch adds read/write apis which are based on nvmem_device. It is common that the drivers like omap cape manager or qcom cpr driver to access bytes directly at particular offset in the eeprom and not from nvmem cell info in DT. These driver would need to get access to the nvmem directly, which is what these new APIS provide. These wrapper apis would help such users to avoid code duplication in there drivers and also avoid them reading a big eeprom blob and parsing it internally in there driver. Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Tested-by: Stefan Wahren <stefan.wahren@i2se.com> Tested-by: Philipp Zabel <p.zabel@pengutronix.de> Tested-by: Rajendra Nayak <rnayak@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05nvmem: Add a simple NVMEM framework for consumersSrinivas Kandagatla
This patch adds just consumers part of the framework just to enable easy review. Up until now, nvmem drivers were stored in drivers/misc, where they all had to duplicate pretty much the same code to register a sysfs file, allow in-kernel users to access the content of the devices they were driving, etc. This was also a problem as far as other in-kernel users were involved, since the solutions used were pretty much different from on driver to another, there was a rather big abstraction leak. This introduction of this framework aims at solving this. It also introduces DT representation for consumer devices to go get the data they require (MAC Addresses, SoC/Revision ID, part numbers, and so on) from the nvmems. Having regmap interface to this framework would give much better abstraction for nvmems on different buses. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> [Maxime Ripard: intial version of the framework] Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Tested-by: Stefan Wahren <stefan.wahren@i2se.com> Tested-by: Philipp Zabel <p.zabel@pengutronix.de> Tested-by: Rajendra Nayak <rnayak@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05nvmem: Add a simple NVMEM framework for nvmem providersSrinivas Kandagatla
This patch adds just providers part of the framework just to enable easy review. Up until now, NVMEM drivers like eeprom were stored in drivers/misc, where they all had to duplicate pretty much the same code to register a sysfs file, allow in-kernel users to access the content of the devices they were driving, etc. This was also a problem as far as other in-kernel users were involved, since the solutions used were pretty much different from on driver to another, there was a rather big abstraction leak. This introduction of this framework aims at solving this. It also introduces DT representation for consumer devices to go get the data they require (MAC Addresses, SoC/Revision ID, part numbers, and so on) from the nvmems. Having regmap interface to this framework would give much better abstraction for nvmems on different buses. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> [Maxime Ripard: intial version of eeprom framework] Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Tested-by: Stefan Wahren <stefan.wahren@i2se.com> Tested-by: Philipp Zabel <p.zabel@pengutronix.de> Tested-by: Rajendra Nayak <rnayak@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>