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2022-03-02nvmem: core: Fix a conflict between MTD and NVMEM on wp-gpios propertyChristophe Kerello1-1/+1
commit f6c052afe6f802d87c74153b7a57c43b2e9faf07 upstream. Wp-gpios property can be used on NVMEM nodes and the same property can be also used on MTD NAND nodes. In case of the wp-gpios property is defined at NAND level node, the GPIO management is done at NAND driver level. Write protect is disabled when the driver is probed or resumed and is enabled when the driver is released or suspended. When no partitions are defined in the NAND DT node, then the NAND DT node will be passed to NVMEM framework. If wp-gpios property is defined in this node, the GPIO resource is taken twice and the NAND controller driver fails to probe. It would be possible to set config->wp_gpio at MTD level before calling nvmem_register function but NVMEM framework will toggle this GPIO on each write when this GPIO should only be controlled at NAND level driver to ensure that the Write Protect has not been enabled. A way to fix this conflict is to add a new boolean flag in nvmem_config named ignore_wp. In case ignore_wp is set, the GPIO resource will be managed by the provider. Fixes: 2a127da461a9 ("nvmem: add support for the write-protect pin") Cc: stable@vger.kernel.org Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20220220151432.16605-2-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27nvmem: core: set size for sysfs bin fileSrinivas Kandagatla1-0/+2
[ Upstream commit 86192251033308bb42f1e9813c962989d8ed07ec ] For some reason we never set the size for nvmem sysfs binary file. Set this. Reported-by: Gilles BULOZ <gilles.buloz@kontron.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20211130133909.6154-1-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-13nvmem: Fix shift-out-of-bound (UBSAN) with byte size cellsStephen Boyd1-1/+2
If a cell has 'nbits' equal to a multiple of BITS_PER_BYTE the logic *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0); will become undefined behavior because nbits modulo BITS_PER_BYTE is 0, and we subtract one from that making a large number that is then shifted more than the number of bits that fit into an unsigned long. UBSAN reports this problem: UBSAN: shift-out-of-bounds in drivers/nvmem/core.c:1386:8 shift exponent 64 is too large for 64-bit type 'unsigned long' CPU: 6 PID: 7 Comm: kworker/u16:0 Not tainted 5.15.0-rc3+ #9 Hardware name: Google Lazor (rev3+) with KB Backlight (DT) Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace+0x0/0x170 show_stack+0x24/0x30 dump_stack_lvl+0x64/0x7c dump_stack+0x18/0x38 ubsan_epilogue+0x10/0x54 __ubsan_handle_shift_out_of_bounds+0x180/0x194 __nvmem_cell_read+0x1ec/0x21c nvmem_cell_read+0x58/0x94 nvmem_cell_read_variable_common+0x4c/0xb0 nvmem_cell_read_variable_le_u32+0x40/0x100 a6xx_gpu_init+0x170/0x2f4 adreno_bind+0x174/0x284 component_bind_all+0xf0/0x264 msm_drm_bind+0x1d8/0x7a0 try_to_bring_up_master+0x164/0x1ac __component_add+0xbc/0x13c component_add+0x20/0x2c dp_display_probe+0x340/0x384 platform_probe+0xc0/0x100 really_probe+0x110/0x304 __driver_probe_device+0xb8/0x120 driver_probe_device+0x4c/0xfc __device_attach_driver+0xb0/0x128 bus_for_each_drv+0x90/0xdc __device_attach+0xc8/0x174 device_initial_probe+0x20/0x2c bus_probe_device+0x40/0xa4 deferred_probe_work_func+0x7c/0xb8 process_one_work+0x128/0x21c process_scheduled_works+0x40/0x54 worker_thread+0x1ec/0x2a8 kthread+0x138/0x158 ret_from_fork+0x10/0x20 Fix it by making sure there are any bits to mask out. Fixes: 69aba7948cbe ("nvmem: Add a simple NVMEM framework for consumers") Cc: Douglas Anderson <dianders@chromium.org> Cc: stable@vger.kernel.org Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20211013124511.18726-1-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-06nvmem: core: fix error handling while validating keepout regionsSrinivas Kandagatla1-2/+5
Current error path on failure of validating keepout regions is calling put_device, eventhough the device is not even registered at that point. Fix this by adding proper error handling of freeing ida and nvmem. Fixes: fd3bb8f54a88 ("nvmem: core: Add support for keepout regions") Cc: <stable@vger.kernel.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20210806085947.22682-5-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-05Merge tag 'char-misc-5.14-rc1' of ↵Linus Torvalds1-8/+15
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 subsystem updates for 5.14-rc1. Included in here are: - habanalabs driver updates - fsl-mc driver updates - comedi driver updates - fpga driver updates - extcon driver updates - interconnect driver updates - mei driver updates - nvmem driver updates - phy driver updates - pnp driver updates - soundwire driver updates - lots of other tiny driver updates for char and misc drivers This is looking more and more like the "various driver subsystems mushed together" tree... All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (292 commits) mcb: Use DEFINE_RES_MEM() helper macro and fix the end address PNP: moved EXPORT_SYMBOL so that it immediately followed its function/variable bus: mhi: pci-generic: Add missing 'pci_disable_pcie_error_reporting()' calls bus: mhi: Wait for M2 state during system resume bus: mhi: core: Fix power down latency intel_th: Wait until port is in reset before programming it intel_th: msu: Make contiguous buffers uncached intel_th: Remove an unused exit point from intel_th_remove() stm class: Spelling fix nitro_enclaves: Set Bus Master for the NE PCI device misc: ibmasm: Modify matricies to matrices misc: vmw_vmci: return the correct errno code siox: Simplify error handling via dev_err_probe() fpga: machxo2-spi: Address warning about unused variable lkdtm/heap: Add init_on_alloc tests selftests/lkdtm: Enable various testable CONFIGs lkdtm: Add CONFIG hints in errors where possible lkdtm: Enable DOUBLE_FAULT on all architectures lkdtm/heap: Add vmalloc linear overflow test lkdtm/bugs: XFAIL UNALIGNED_LOAD_STORE_WRITE ...
2021-06-11nvmem: core: add a missing of_node_putChristophe JAILLET1-3/+6
'for_each_child_of_node' performs an of_node_get on each iteration, so a return from the middle of the loop requires an of_node_put. Fixes: e888d445ac33 ("nvmem: resolve cells from DT at registration time") Cc: <stable@vger.kernel.org> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20210611102321.11509-1-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-11nvmem: prepare basics for FRAM supportJiri Prchal1-0/+4
Added enum and string for FRAM (ferroelectric RAM) to expose it as file named "fram". Added documentation of sysfs file. Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz> Link: https://lore.kernel.org/r/20210611094601.95131-2-jiri.prchal@aksignal.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-11nvmem: core: constify nvmem_cell_read_variable_common() return valueDouglas Anderson1-5/+5
The caller doesn't modify the memory pointed to by the pointer so it can be const. Suggested-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20210611083348.20170-9-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-10nvmem: core: allow specifying of_nodeMichael Walle1-1/+3
Until now, the of_node of the parent device is used. Some devices provide more than just the nvmem provider. To avoid name space clashes, add a way to allow specifying the nvmem cells in subnodes. Consider the following example: flash@0 { compatible = "jedec,spi-nor"; partitions { compatible = "fixed-partitions"; #address-cells = <1>; #size-cells = <1>; partition@0 { reg = <0x000000 0x010000>; }; }; otp { compatible = "user-otp"; #address-cells = <1>; #size-cells = <1>; serial-number@0 { reg = <0x0 0x8>; }; }; }; There the nvmem provider might be the MTD partition or the OTP region of the flash. Add a new config->of_node parameter, which if set, will be used instead of the parent's of_node. Signed-off-by: Michael Walle <michael@walle.cc> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20210424110608.15748-2-michael@walle.cc
2021-04-02nvmem: core: Fix unintentional sign extension issueColin Ian King1-1/+1
The shifting of the u8 integer buf[3] by 24 bits to the left will be promoted to a 32 bit signed int and then sign-extended to a u64. In the event that the top bit of buf[3] is set then all then all the upper 32 bits of the u64 end up as also being set because of the sign-extension. Fix this by casting buf[i] to a u64 before the shift. Fixes: a28e824fb827 ("nvmem: core: Add functions to make number reading easy") Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Addresses-Coverity: ("Unintended sign extension") Link: https://lore.kernel.org/r/20210330111241.19401-8-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/+95
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>
2021-02-04nvmem: core: skip child nodes not matching bindingAhmad Fatoum1-1/+3
The nvmem cell binding applies to all eeprom child nodes matching "^.*@[0-9a-f]+$" without taking a compatible into account. Linux drivers, like at24, are even more extensive and assume _all_ at24 eeprom child nodes to be nvmem cells since e888d445ac33 ("nvmem: resolve cells from DT at registration time"). Since df5f3b6f5357 ("dt-bindings: nvmem: stm32: new property for data access"), the additionalProperties: True means it's Ok to have other properties as long as they don't match "^.*@[0-9a-f]+$". The barebox bootloader extends the MTD partitions binding to EEPROM and can fix up following device tree node: &eeprom { partitions { compatible = "fixed-partitions"; }; }; This is allowed binding-wise, but drivers using nvmem_register() like at24 will fail to parse because the function expects all child nodes to have a reg property present. This results in the whole EEPROM driver probe failing despite the device tree being correct. Fix this by skipping nodes lacking a reg property instead of returning an error. This effectively makes the drivers adhere to the binding because all nodes with a unit address must have a reg property and vice versa. Fixes: e888d445ac33 ("nvmem: resolve cells from DT at registration time"). Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20210129171430.11328-6-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-04nvmem: core: Fix a resource leak on error in nvmem_add_cells_from_of()Dan Carpenter1-0/+1
This doesn't call of_node_put() on the error path so it leads to a memory leak. Fixes: 0749aa25af82 ("nvmem: core: fix regression in of_nvmem_cell_get()") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20210129171430.11328-2-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-27nvmem: core: Add support for keepout regionsEvan Green1-4/+149
Introduce support into the nvmem core for arrays of register ranges that should not result in actual device access. For these regions a constant byte (repeated) is returned instead on read, and writes are quietly ignored and returned as successful. This is useful for instance if certain efuse regions are protected from access by Linux because they contain secret info to another part of the system (like an integrated modem). Signed-off-by: Evan Green <evgreen@chromium.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20201127102837.19366-3-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-27nvmem: core: fix possibly memleak when use nvmem_cell_info_to_nvmem_cell()Vadym Kochan1-9/+24
Fix missing 'kfree_const(cell->name)' when call to nvmem_cell_info_to_nvmem_cell() in several places: * after nvmem_cell_info_to_nvmem_cell() failed during nvmem_add_cells() * during nvmem_device_cell_{read,write} when cell->name is kstrdup'ed() without calling kfree_const() at the end, but really there is no reason to do that 'dup, because the cell instance is allocated on the stack for some short period to be read/write without exposing it to the caller. So the new nvmem_cell_info_to_nvmem_cell_nodup() helper is introduced which is used to convert cell_info -> cell without name duplication as a lighweight version of nvmem_cell_info_to_nvmem_cell(). Fixes: e2a5402ec7c6 ("nvmem: Add nvmem_device based consumer apis.") Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Vadym Kochan <vadym.kochan@plvision.eu> Link: https://lore.kernel.org/r/20200923204456.14032-1-vadym.kochan@plvision.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-17nvmem: core: fix missing of_node_put() in of_nvmem_device_get()Vadym Kochan1-1/+4
of_parse_phandle() returns device_node with incremented ref count which needs to be decremented by of_node_put() when device_node is not used. Fixes: e2a5402ec7c6 ("nvmem: Add nvmem_device based consumer apis.") Signed-off-by: Vadym Kochan <vadym.kochan@plvision.eu> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200917134437.16637-5-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-17nvmem: switch to simpler IDA interfaceBartosz Golaszewski1-3/+3
We don't need to specify any ranges when allocating IDs so we can switch to ida_alloc() and ida_free() instead of the ida_simple_ counterparts. ida_simple_get(ida, 0, 0, gfp) is equivalent to ida_alloc_range(ida, 0, UINT_MAX, gfp) which is equivalent to ida_alloc(ida, gfp). Note: IDR will never actually allocate an ID larger than INT_MAX. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200917134437.16637-4-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-17nvmem: core: Use kobj_to_dev() instead of container_of()Tian Tao1-3/+3
Use kobj_to_dev() instead of container_of() Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200917134437.16637-3-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29nvmem: core: add support to auto devidSrinivas Kandagatla1-2/+8
For nvmem providers which have multiple instances, it is required to suffix the provider name with proper id, so that they do not confict for the same name. Currently the core does not handle this case properly eventhough core already has logic to generate the id. This patch add new devid type NVMEM_DEVID_AUTO for providers to be able to allow core to assign id and append it to provier name. Reported-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Link: https://lore.kernel.org/r/20200722100705.7772-8-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/+15
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>
2020-07-29nvmem: core: Grammar fixes for help textAndreas Färber1-6/+6
It's "an unsigned" but "a U". Similarly, "an entry" but "a binary entry". While at it, also drop superfluous articles for negative and zero. Signed-off-by: Andreas Färber <afaerber@suse.de> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200722100705.7772-6-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29nvmem: Enforce nvmem stride in the sysfs interfaceDouglas Anderson1-0/+6
The 'struct nvmem_config' has a stride attribute that specifies the needed alignment for accesses into the nvmem. This is used in nvmem_cell_info_to_nvmem_cell() but not in the sysfs read/write functions. If the alignment is important in one place it's important everywhere, so let's add enforcement. For now we'll consider it totally invalid to access with the wrong alignment. We could relax this in the read case where we could just read some extra bytes and throw them away. Relaxing it in the write case seems harder (and less safe?) since we'd have to read some data first and then write it back. To keep it symmetric we'll just disallow it in both cases. Reported-by: Ravi Kumar Bokka <rbokka@codeaurora.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Ravi Kumar Bokka <rbokka@codeaurora.org> Tested-by: Ravi Kumar Bokka <rbokka@codeaurora.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200722100705.7772-4-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-15nvmem: ensure sysfs writes handle write-protect pinMichael Auchter1-26/+26
Commit 2a127da461a9 ("nvmem: add support for the write-protect pin") added support for handling write-protect pins to the nvmem core, and Commit 1c89074bf850 ("eeprom: at24: remove the write-protect pin support") retrofitted the at24 driver to use this support. These changes broke write() on the nvmem sysfs attribute for eeproms which utilize a write-protect pin, as the write callback invokes the nvmem device's reg_write callback directly which no longer handles changing the state of the write-protect pin. Change the read and write callbacks for the sysfs attribute to invoke nvmme_reg_read/nvmem_reg_write helpers which handle this, rather than calling reg_read/reg_write directly. Fixes: 2a127da461a9 ("nvmem: add support for the write-protect pin") Signed-off-by: Michael Auchter <michael.auchter@ni.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200511145042.31223-3-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28nvmem: core: cleanup old eeprom compat entry attributesSrinivas Kandagatla1-38/+14
file permission are derived based on various configs for default nvmem sysfs file, reuse it to create the eeprom compat file too. Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200417121306.23121-1-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25nvmem: core: remove nvmem_sysfs_get_groups()Srinivas Kandagatla1-2/+272
Now that we are using is_bin_visible callback, we do not need nvmem_sysfs_get_groups() anymore so move all the relevant data-structures and code to core.c Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200325131951.31887-3-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25nvmem: core: use is_bin_visible for permissionsSrinivas Kandagatla1-1/+1
By using is_bin_visible callback to set permissions will remove a large list of attribute groups. These group permissions can be dynamically derived in the callback. Also add checks for read/write callbacks and set permissions accordingly. Suggested-by: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200325131951.31887-2-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25nvmem: core: use device_register and device_unregisterSrinivas Kandagatla1-5/+2
use device_register/unregister instead of spliting them with no use. Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200324171600.15606-2-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-25nvmem: core: add root_only member to nvmem device structSrinivas Kandagatla1-0/+1
As we are planning to move to use sysfs is_bin_visible callback, having root_only as part of nvmem_device will help decide correct permissions. Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200325122116.15096-2-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-19nvmem: core: validate nvmem config before parsingSrinivas Kandagatla1-0/+3
nvmem provider has to provide either reg_read/write, add a check to enforce this. Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200310132257.23358-9-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-19nvmem: release the write-protect pinKhouloud Touil1-0/+1
Put the write-protect GPIO descriptor in nvmem_release() so that it can be automatically released when the associated device's reference count drops to 0. Fixes: 2a127da461a9 ("nvmem: add support for the write-protect pin") Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Khouloud Touil <ktouil@baylibre.com> Cc: stable <stable@vger.kernel.org> [Bartosz: tweak the commit message] Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200310132257.23358-8-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-19nvmem: fix memory leak in error pathBartosz Golaszewski1-2/+6
We need to free the ida mapping and nvmem struct if the write-protect GPIO lookup fails. Fixes: 2a127da461a9 ("nvmem: add support for the write-protect pin") Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200310132257.23358-7-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-19nvmem: add a newline for readabilityBartosz Golaszewski1-0/+1
Visibly separate the GPIO request from the previous operation in the code with a newline. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200310132257.23358-6-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-19nvmem: remove a stray newline in nvmem_register()Bartosz Golaszewski1-1/+0
Two newlines are unnecessary - remove one. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200310132257.23358-5-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-19nvmem: core: add nvmem_cell_read_u64Yangtao Li1-0/+15
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>
2020-03-19nvmem: core: add nvmem_cell_read_commonYangtao Li1-35/+19
Now there are nvmem_cell_read_u16 and nvmem_cell_read_u32. They are very similar, let's strip out a common part. And use nvmem_cell_read_common to simplify their implementation. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200310132257.23358-3-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-07Merge branch 'i2c/for-5.6' of ↵Linus Torvalds1-2/+17
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c updates from Wolfram Sang: "i2c core: - huge improvements and refactorizations of the Linux I2C documentation (lots of thanks to Luca for doing it and Jean for the careful review) - subsystem wide API conversion to i2c_new_client_device() - remove obsolete parport-light driver - smaller core updates (removal of 'extern', enabling more compile testing, use more helper macros) - and quite a bunch of driver updates (new IDs, simplifications, better PM, support of atomic transfers and other improvements) i2c-mux: - The main feature is the idle-state rework of the pca954x driver from Biwen Li at24 driver: - minor maintenance: update the license tag, sort headers - move support for the write-protect pin into nvmem core - add a reference to the new wp-gpios property in nvmem to at25 bindings - add support for regulator and pm_runtime control" * 'i2c/for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (91 commits) i2c: cros-ec-tunnel: Fix ACPI identifier i2c: cros-ec-tunnel: Fix slave device enumeration i2c: stm32f7: add PM_SLEEP suspend/resume support i2c: cadence: Fix wording in i2c-cadence driver i2c: cadence: Fix power management order of operations i2c: cadence: Fix error printing in case of defer i2c: cadence: Handle transfer_size rollover i2c: i801: Add support for Intel Comet Lake PCH-V docs: i2c: writing-clients: properly name the stop condition docs: i2c: i2c-protocol: use same wording as smbus-protocol docs: i2c: rename sections so the overall picture is clearer docs: i2c: old-module-parameters: use monospace instead of "" docs: i2c: old-module-parameters: clarify this is for obsolete kernels docs: i2c: old-module-parameters: fix internal hyperlink docs: i2c: instantiating-devices: use monospace for sysfs attributes docs: i2c: instantiating-devices: rearrange static instatiation docs: i2c: instantiating-devices: fix internal hyperlink docs: i2c: smbus-protocol: improve I2C Block transactions description docs: i2c: smbus-protocol: fix punctuation docs: i2c: smbus-protocol: fix typo ...
2020-01-10nvmem: core: fix memory abort in cleanup pathBitan Biswas1-3/+5
nvmem_cell_info_to_nvmem_cell implementation has static allocation of name. nvmem_add_cells_from_of() call may return error and kfree name results in memory abort. Use kstrdup_const() and kfree_const calls for name alloc and free. Unable to handle kernel paging request at virtual address ffffffffffe44888 Mem abort info: ESR = 0x96000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 swapper pgtable: 64k pages, 48-bit VAs, pgdp=00000000815d0000 [ffffffffffe44888] pgd=0000000081d30803, pud=0000000081d30803, pmd=0000000000000000 Internal error: Oops: 96000006 [#1] PREEMPT SMP Modules linked in: CPU: 2 PID: 43 Comm: kworker/2:1 Tainted Hardware name: quill (DT) Workqueue: events deferred_probe_work_func pstate: a0000005 (NzCv daif -PAN -UAO) pc : kfree+0x38/0x278 lr : nvmem_cell_drop+0x68/0x80 sp : ffff80001284f9d0 x29: ffff80001284f9d0 x28: ffff0001f677e830 x27: ffff800011b0b000 x26: ffff0001c36e1008 x25: ffff8000112ad000 x24: ffff8000112c9000 x23: ffffffffffffffea x22: ffff800010adc7f0 x21: ffffffffffe44880 x20: ffff800011b0b068 x19: ffff80001122d380 x18: ffffffffffffffff x17: 00000000d5cb4756 x16: 0000000070b193b8 x15: ffff8000119538c8 x14: 0720072007200720 x13: 07200720076e0772 x12: 07750762072d0765 x11: 0773077507660765 x10: 072f073007300730 x9 : 0730073207380733 x8 : 0000000000000151 x7 : 07660765072f0720 x6 : ffff0001c00e0f00 x5 : 0000000000000000 x4 : ffff0001c0b43800 x3 : ffff800011b0b068 x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffffffdfffe00000 Call trace: kfree+0x38/0x278 nvmem_cell_drop+0x68/0x80 nvmem_device_remove_all_cells+0x2c/0x50 nvmem_register.part.9+0x520/0x628 devm_nvmem_register+0x48/0xa0 tegra_fuse_probe+0x140/0x1f0 platform_drv_probe+0x50/0xa0 really_probe+0x108/0x348 driver_probe_device+0x58/0x100 __device_attach_driver+0x90/0xb0 bus_for_each_drv+0x64/0xc8 __device_attach+0xd8/0x138 device_initial_probe+0x10/0x18 bus_probe_device+0x90/0x98 deferred_probe_work_func+0x74/0xb0 process_one_work+0x1e0/0x358 worker_thread+0x208/0x488 kthread+0x118/0x120 ret_from_fork+0x10/0x18 Code: d350feb5 f2dffbe0 aa1e03f6 8b151815 (f94006a0) ---[ end trace 49b1303c6b83198e ]--- Fixes: badcdff107cbf ("nvmem: Convert to using %pOFn instead of device_node.name") Signed-off-by: Bitan Biswas <bbiswas@nvidia.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20200109104017.6249-5-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-10nvmem: fix a 'makes pointer from integer without a cast' build warningBartosz Golaszewski1-1/+1
nvmem_register() returns a pointer, not a long int. Use ERR_CAST() to cast the struct gpio_desc pointer to struct nvmem_device. Reported-by: kbuild test robot <lkp@intel.com> Fixes: 2a127da461a9 ("nvmem: add support for the write-protect pin") Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
2020-01-09nvmem: add support for the write-protect pinKhouloud Touil1-2/+17
The write-protect pin handling looks like a standard property that could benefit other users if available in the core nvmem framework. Instead of modifying all the memory drivers to check this pin, make the NVMEM subsystem check if the write-protect GPIO being passed through the nvmem_config or defined in the device tree and pull it low whenever writing to the memory. There was a suggestion for introducing the gpiodesc from pdata, but as pdata is already removed it could be replaced by adding it to nvmem_config. Reference: https://lists.96boards.org/pipermail/dev/2018-August/001056.html Signed-off-by: Khouloud Touil <ktouil@baylibre.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2019-10-07nvmem: core: add nvmem_device_findThomas Bogendoerfer1-34/+27
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
2019-07-30drivers: Introduce device lookup variants by of_nodeSuzuki K Poulose1-6/+1
Introduce wrappers for {bus/driver/class}_find_device() to locate devices by its of_node. Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <maxime.ripard@bootlin.com> Cc: dri-devel@lists.freedesktop.org Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: devicetree@vger.kernel.org Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: linux-i2c@vger.kernel.org Cc: linux-rockchip@lists.infradead.org Cc: linux-spi@vger.kernel.org Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Cc: Takashi Iwai <tiwai@suse.com> Cc: Alan Tull <atull@kernel.org> Cc: linux-fpga@vger.kernel.org Cc: Peter Rosin <peda@axentia.se> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Heiner Kallweit <hkallweit1@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Thor Thayer <thor.thayer@linux.intel.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Peter Rosin <peda@axentia.se> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Lee Jones <lee.jones@linaro.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> # I2C part Acked-by: Moritz Fischer <mdf@kernel.org> # For FPGA part Acked-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20190723221838.12024-3-suzuki.poulose@arm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-24bus_find_device: Unify the match callback with class_find_deviceSuzuki K Poulose1-1/+1
There is an arbitrary difference between the prototypes of bus_find_device() and class_find_device() preventing their callers from passing the same pair of data and match() arguments to both of them, which is the const qualifier used in the prototype of class_find_device(). If that qualifier is also used in the bus_find_device() prototype, it will be possible to pass the same match() callback function to both bus_find_device() and class_find_device(), which will allow some optimizations to be made in order to avoid code duplication going forward. Also with that, constify the "data" parameter as it is passed as a const to the match function. For this reason, change the prototype of bus_find_device() to match the prototype of class_find_device() and adjust its callers to use the const qualifier in accordance with the new prototype of it. Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Andreas Noever <andreas.noever@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Corey Minyard <minyard@acm.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David Kershner <david.kershner@unisys.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: David Airlie <airlied@linux.ie> Cc: Felipe Balbi <balbi@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Harald Freudenberger <freude@linux.ibm.com> Cc: Hartmut Knaack <knaack.h@gmx.de> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jonathan Cameron <jic23@kernel.org> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: Len Brown <lenb@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michael Jamet <michael.jamet@intel.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: Sebastian Ott <sebott@linux.ibm.com> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Cc: Yehezkel Bernat <YehezkelShB@gmail.com> Cc: rafael@kernel.org Acked-by: Corey Minyard <minyard@acm.org> Acked-by: David Kershner <david.kershner@unisys.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> # for the I2C parts Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25nvmem: core: add NVMEM_SYSFS KconfigSrinivas Kandagatla1-260/+4
Many nvmem providers are not very keen on having default sysfs nvmem entry, as most of the usecases for them are inside kernel itself. And in some cases read/writes to some areas in nvmem are restricted and trapped at secure monitor level, so accessing them from userspace would result in board reboots. This patch adds new NVMEM_SYSFS Kconfig to make binary sysfs entry an optional one. This provision will give more flexibility to users. This patch also moves existing sysfs code to a new file so that its not compiled in when its not really required. Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Gaurav Kohli <gkohli@codeaurora.org> Tested-by: Gaurav Kohli <gkohli@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25nvmem: core: fix read buffer in placeJorge Ramirez-Ortiz1-5/+10
When the bit_offset in the cell is zero, the pointer to the msb will not be properly initialized (ie, will still be pointing to the first byte in the buffer). This being the case, if there are bits to clear in the msb, those will be left untouched while the mask will incorrectly clear bit positions on the first byte. This commit also makes sure that any byte unused in the cell is cleared. Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25nvmem: core: add nvmem_cell_read_u16Fabrice Gasnier1-0/+37
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>
2019-02-19nvmem: core: don't check the return value of notifier chain callBartosz Golaszewski1-3/+1
blocking_notifier_call_chain() returns the value returned by the last registered callback. A positive return value doesn't indicate an error and an nvmem device should correctly register irrespective of any notifier callback failures. Drop the retval check. Fixes: bee1138bea15 ("nvmem: add a notifier chain") Cc: stable@vger.kernel.org Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-31nvmem: core: Avoid useless iterations in nvmem_cell_get_from_lookup()Alban Bedel1-3/+2
Once the correct cell has been found there is no need to continue iterating, just stop there. While at it replace the goto used to leave the loop with simple break statements. Signed-off-by: Alban Bedel <albeu@free.fr> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-31nvmem: core: Fix device reference leakAlban Bedel1-0/+2
__nvmem_device_get() make use of bus_find_device() to get the relevant device and this function increase the reference count of the device found, however this is not accounted for anywhere. Fix __nvmem_device_get() and __nvmem_device_put() to properly release this reference count. Signed-off-by: Alban Bedel <albeu@free.fr> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-31nvmem: core: Always reference the device returned by nvmem_device_get()Alban Bedel1-1/+1
In nvmem_device_get(), when the device lookup fails with DT it currently fallback on nvmem_find() which is wrong for two reasons. First nvmem_find() return NULL when nothing is found instead of an ERR_PTR. But nvmem_find() also just lookup the device, it doesn't reference the module and increment the reference count like it is done in the DT path. To fix this we replace the call to nvmem_find() with a call to __nvmem_device_get() which does all the referencing and return a proper ERR_PTR in case of error. Signed-off-by: Alban Bedel <albeu@free.fr> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-31nvmem: core: Properly handle connection ID in of_nvmem_device_get()Alban Bedel1-3/+4
of_nvmem_device_get() would crash if NULL was passed as a connection ID. Rework this to use the usual sementic of assuming the first connection when no connection ID is given. Furthermore of_nvmem_device_get() would return -EINVAL when it failed to resolve the connection, making it impossible to properly implement an optional connection. Return -ENOENT instead to let the caller know that the connection doesn't exists. Signed-off-by: Alban Bedel <albeu@free.fr> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>