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2021-09-14nvmem: core: Add stubs for nvmem_cell_read_variable_le_u32/64 if !CONFIG_NVMEMDouglas Anderson1-0/+14
When I added nvmem_cell_read_variable_le_u32() and nvmem_cell_read_variable_le_u64() I forgot to add the "static inline" stub functions for when CONFIG_NVMEM wasn't defined. Add them now. This was causing problems with randconfig builds that compiled `drivers/soc/qcom/cpr.c`. Fixes: 6feba6a62c57 ("PM: AVS: qcom-cpr: Use nvmem_cell_read_variable_le_u32()") Fixes: a28e824fb827 ("nvmem: core: Add functions to make number reading easy") Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20210913160551.12907-1-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-02nvmem: core: Add functions to make number reading easyDouglas Anderson1-0/+4
Sometimes the clients of nvmem just want to get a number out of nvmem. They don't want to think about exactly how many bytes the nvmem cell took up. They just want the number. Let's make it easy. In general this concept is useful because nvmem space is precious and usually the fewest bits are allocated that will hold a given value on a given system. However, even though small numbers might be fine on one system that doesn't mean that logically the number couldn't be bigger. Imagine nvmem containing a max frequency for a component. On one system perhaps that fits in 16 bits. On another system it might fit in 32 bits. The code reading this number doesn't care--it just wants the number. We'll provide two functions: nvmem_cell_read_variable_le_u32() and nvmem_cell_read_variable_le_u64(). Comparing these to the existing functions like nvmem_cell_read_u32(): * These new functions have no problems if the value was stored in nvmem in fewer bytes. It's OK to use these function as long as the value stored will fit in 32-bits (or 64-bits). * These functions avoid problems that the earlier APIs had with bit offsets. For instance, you can't use nvmem_cell_read_u32() to read a value has nbits=32 and bit_offset=4 because the nvmem cell must be at least 5 bytes big to hold this value. The new API accounts for this and works fine. * These functions make it very explicit that they assume that the number was stored in little endian format. The old functions made this assumption whenever bit_offset was non-zero (see nvmem_shift_read_buffer_in_place()) but didn't whenever the bit_offset was zero. NOTE: it's assumed that we don't need an 8-bit or 16-bit version of this function. The 32-bit version of the function can be used to read 8-bit or 16-bit data. At the moment, I'm only adding the "unsigned" versions of these functions, but if it ends up being useful someone could add a "signed" version that did 2's complement sign extension. At the moment, I'm only adding the "little endian" versions of these functions. Adding the "big endian" version would require adding "big endian" support to nvmem_shift_read_buffer_in_place(). Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20210330111241.19401-7-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29nvmem: core: Add nvmem_cell_read_u8()Andreas Färber1-0/+1
Complement the u16, u32 and u64 helpers with a u8 variant to ease accessing byte-sized values. This helper will be useful for Realtek Digital Home Center platforms, which store some byte and sub-byte sized values in non-volatile memory. Signed-off-by: Andreas Färber <afaerber@suse.de> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200722100705.7772-7-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-19nvmem: core: add nvmem_cell_read_u64Yangtao Li1-0/+7
Add nvmem_cell_read_u64() helper to ease read of an u64 value on consumer side. This helper is useful on some sunxi platform that has 64 bits data cells stored in no volatile memory. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200310132257.23358-4-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-27Merge tag 'char-misc-5.5-rc1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here is the big set of char/misc and other driver patches for 5.5-rc1 Loads of different things in here, this feels like the catch-all of driver subsystems these days. Full details are in the shortlog, but nothing major overall, just lots of driver updates and additions. All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (198 commits) char: Fix Kconfig indentation, continued habanalabs: add more protection of device during reset habanalabs: flush EQ workers in hard reset habanalabs: make the reset code more consistent habanalabs: expose reset counters via existing INFO IOCTL habanalabs: make code more concise habanalabs: use defines for F/W files habanalabs: remove prints on successful device initialization habanalabs: remove unnecessary checks habanalabs: invalidate MMU cache only once habanalabs: skip VA block list update in reset flow habanalabs: optimize MMU unmap habanalabs: prevent read/write from/to the device during hard reset habanalabs: split MMU properties to PCI/DRAM habanalabs: re-factor MMU masks and documentation habanalabs: type specific MMU cache invalidation habanalabs: re-factor memory module code habanalabs: export uapi defines to user-space habanalabs: don't print error when queues are full habanalabs: increase max jobs number to 512 ...
2019-11-05nvmem: core: fix nvmem_cell_write inline functionSebastian Reichel1-1/+1
nvmem_cell_write's buf argument uses different types based on the configuration of CONFIG_NVMEM. The function prototype for enabled NVMEM uses 'void *' type, but the static dummy function for disabled NVMEM uses 'const char *' instead. Fix the different behaviour by always expecting a 'void *' typed buf argument. Fixes: 7a78a7f7695b ("power: reset: nvmem-reboot-mode: use NVMEM as reboot mode write interface") Reported-by: kbuild test robot <lkp@intel.com> Cc: Han Nandor <nandor.han@vaisala.com> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com> Reviewed-By: Han Nandor <nandor.han@vaisala.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20191029114240.14905-2-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-07nvmem: core: add nvmem_device_findThomas Bogendoerfer1-0/+9
nvmem_device_find provides a way to search for nvmem devices with the help of a match function simlair to bus_find_device. Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de> Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Lee Jones <lee.jones@linaro.org> Cc: David S. Miller <davem@davemloft.net> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: netdev@vger.kernel.org Cc: linux-rtc@vger.kernel.org Cc: linux-serial@vger.kernel.org
2019-04-25nvmem: core: add nvmem_cell_read_u16Fabrice Gasnier1-0/+7
Add nvmem_cell_read_u16() helper to ease read of an u16 value on consumer side. This is inspired by nvmem_cell_read_u32() function. This helper is useful on stm32 that has 16 bits data cells stored in non volatile memory. Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-28nvmem: use EOPNOTSUPP instead of ENOSYSBartosz Golaszewski1-15/+15
Checkpatch emits warnings when using ENOSYS. Some of the frameworks started using EOPNOTSUPP as return values for API functions when given subsystem is disabled in Kconfig. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-28nvmem: make the naming of arguments in nvmem_cell_get() consistentBartosz Golaszewski1-6/+6
The argument representing the cell name in the nvmem_cell_get() family of functions is not consistend between function prototypes and definitions. Name it 'id' in all those routines. This is in line with other frameworks and can represent both the DT cell name from the nvmem-cell-names property as well as the con_id field from cell lookup entries. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-28nvmem: use SPDX license identifiersBartosz Golaszewski1-4/+1
Use SPDX license identiefiers to core nvmem files and remove GPL 2.0 license boilerplate. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-28nvmem: add a notifier chainBartosz Golaszewski1-0/+21
Add a blocking notifier chain with four events (add and remove for both devices and cells) so that users can get notified about the addition of nvmem resources they're waiting for. We'll use this instead of the at24 setup callback in the mityomapl138 board file. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-28nvmem: add support for cell lookups from machine codeBartosz Golaszewski1-0/+28
Add a way for machine code users to associate devices with nvmem cells. This restores the support for non-DT systems but following a different approach. Cells must now be associated with devices using provided routines and data structures before they can be retrieved using nvmem_cell_get(). It's still possible to define cells statically in nvmem_config but cells created this way still need to be associated with consumers using lookup entries. Note that nvmem_find() must be moved higher in the source file as we want to call it from __nvmem_device_get() for devices that don't have a device node. The signature of __nvmem_device_get() is also changed as it's no longer used to retrieve cells. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-28nvmem: provide nvmem_dev_name()Bartosz Golaszewski1-0/+8
Kernel users don't have any means of checking the names of nvmem devices. Add a routine that returns the name of the nvmem provider. This will be useful for future nvmem notifier subscribers - otherwise they can't check what device is being added/removed. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28nvmem: include linux/err.h from headerSrinivas Kandagatla1-0/+3
missing err.h header file can cause simillar errors like below in some configurations. "error: implicit declaration of function 'ERR_PTR' [-Werror=implicit-function-declaration]" This adds the missing include to ensure we can always include the header. Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28nvmem: core: Add nvmem_cell_read_u32Leonard Crestez1-0/+7
This function does a quick and easy read of an u32 value without any kind of resource management code on the consumer side. Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Reviewed-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25nvmem: Declare nvmem_cell_read() consistentlyGuenter Roeck1-1/+1
nvmem_cell_read() is declared as void * if CONFIG_NVMEM is enabled, and as char * otherwise. This can result in a build warning if CONFIG_NVMEM is not enabled and a caller asigns the result to a type other than char * without using a typecast. Use a consistent declaration to avoid the problem. Fixes: e2a5402ec7c6 ("nvmem: Add nvmem_device based consumer apis.") Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> 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 Kandagatla1-0/+73
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 Kandagatla1-0/+61
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 Kandagatla1-0/+23
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>