commit 5d388fa01fa6eb310ac023a363a6cb216d9d8fe9 upstream.
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: 69aba7948c ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 63879e2964bceee2aa5bbe8b99ea58bba28bb64f upstream.
'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: e888d445ac ("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>
[ Upstream commit 0445efacec75b85c2a3c176957ee050ba9be53f0 ]
The nvmem cell binding applies to all eeprom child nodes matching
"^.*@[0-9a-f]+$" without taking a compatible into account.
Linux drivers, like at24, are even more extensive and assume
_all_ at24 eeprom child nodes to be nvmem cells since e888d445ac
("nvmem: resolve cells from DT at registration time").
Since df5f3b6f53 ("dt-bindings: nvmem: stm32: new property for
data access"), the additionalProperties: True means it's Ok to have
other properties as long as they don't match "^.*@[0-9a-f]+$".
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: e888d445ac ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fc9eec4d64 ]
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: e2a5402ec7 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8d9eb0d6d5 upstream.
qfprom has different address spaces for read and write. Reads are
always done from corrected address space, where as writes are done
on raw address space.
Writing to corrected address space is invalid and ignored, so it
does not make sense to have this support in the driver which only
supports corrected address space regions at the moment.
Fixes: 4ab11996b4 ("nvmem: qfprom: Add Qualcomm QFPROM support.")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200522113341.7728-1-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3c91ef69a3 upstream.
Return -EPERM if reg_read is NULL in bin_attr_nvmem_read() or if
reg_write is NULL in bin_attr_nvmem_write().
This prevents NULL dereferences such as the one described in
03cd45d2e2 ("thunderbolt: Prevent crash if non-active NVMem file is
read")
Signed-off-by: Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200310132257.23358-10-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c33c585f1b ]
If software running before the OCOTP driver is loaded left the
controller with the error status pending, the driver will never
be able to complete the read timing setup. Reset the error status
on probe to make sure the controller is in usable state.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20191029114240.14905-6-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Here is the big char/misc driver pull request for 5.4-rc1.
As has been happening in previous releases, more and more individual
driver subsystem trees are ending up in here. Now if that is good or
bad I can't tell, but hopefully it makes your life easier as it's more
of an aggregation of trees together to one merge point for you.
Anyway, lots of stuff in here:
- habanalabs driver updates
- thunderbolt driver updates
- misc driver updates
- coresight and intel_th hwtracing driver updates
- fpga driver updates
- extcon driver updates
- some dma driver updates
- char driver updates
- android binder driver updates
- nvmem driver updates
- phy driver updates
- parport driver fixes
- pcmcia driver fix
- uio driver updates
- w1 driver updates
- configfs fixes
- other assorted driver updates
All of these have been in linux-next for a long time with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCXYIT1g8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ym9lwCgrHZlMMvfYNVm6GQ5ge58JJsVTL4AoNatTcL4
hfVMA6pCHWBjV65xVSf6
=Tijw
-----END PGP SIGNATURE-----
Merge tag 'char-misc-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH:
"Here is the big char/misc driver pull request for 5.4-rc1.
As has been happening in previous releases, more and more individual
driver subsystem trees are ending up in here. Now if that is good or
bad I can't tell, but hopefully it makes your life easier as it's more
of an aggregation of trees together to one merge point for you.
Anyway, lots of stuff in here:
- habanalabs driver updates
- thunderbolt driver updates
- misc driver updates
- coresight and intel_th hwtracing driver updates
- fpga driver updates
- extcon driver updates
- some dma driver updates
- char driver updates
- android binder driver updates
- nvmem driver updates
- phy driver updates
- parport driver fixes
- pcmcia driver fix
- uio driver updates
- w1 driver updates
- configfs fixes
- other assorted driver updates
All of these have been in linux-next for a long time with no reported
issues"
* tag 'char-misc-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (200 commits)
misc: mic: Use PTR_ERR_OR_ZERO rather than its implementation
habanalabs: correctly cast variable to __le32
habanalabs: show correct id in error print
habanalabs: stop using the acronym KMD
habanalabs: display card name as sensors header
habanalabs: add uapi to retrieve aggregate H/W events
habanalabs: add uapi to retrieve device utilization
habanalabs: Make the Coresight timestamp perpetual
habanalabs: explicitly set the queue-id enumerated numbers
habanalabs: print to kernel log when reset is finished
habanalabs: replace __le32_to_cpu with le32_to_cpu
habanalabs: replace __cpu_to_le32/64 with cpu_to_le32/64
habanalabs: Handle HW_IP_INFO if device disabled or in reset
habanalabs: Expose devices after initialization is done
habanalabs: improve security in Debug IOCTL
habanalabs: use default structure for user input in Debug IOCTL
habanalabs: Add descriptive name to PSOC app status register
habanalabs: Add descriptive names to PSOC scratch-pad registers
habanalabs: create two char devices per ASIC
habanalabs: change device_setup_cdev() to be more generic
...
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQQUwxxKyE5l/npt8ARiEGxRG/Sl2wUCXYAIeQAKCRBiEGxRG/Sl
2/SzAQDEnoNxzV/R5kWFd+2kmFeY3cll0d99KMrWJ8om+kje6QD/cXxZHzFm+T1L
UPF66k76oOODV7cyndjXnTnRXbeCRAM=
=Szby
-----END PGP SIGNATURE-----
Merge tag 'leds-for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds
Pull LED updates from Jacek Anaszewski:
"In this cycle we've finally managed to contribute the patch set
sorting out LED naming issues. Besides that there are many changes
scattered among various LED class drivers and triggers.
LED naming related improvements:
- add new 'function' and 'color' fwnode properties and deprecate
'label' property which has been frequently abused for conveying
vendor specific names that have been available in sysfs anyway
- introduce a set of standard LED_FUNCTION* definitions
- introduce a set of standard LED_COLOR_ID* definitions
- add a new {devm_}led_classdev_register_ext() API with the
capability of automatic LED name composition basing on the
properties available in the passed fwnode; the function is
backwards compatible in a sense that it uses 'label' data, if
present in the fwnode, for creating LED name
- add tools/leds/get_led_device_info.sh script for retrieving LED
vendor, product and bus names, if applicable; it also performs
basic validation of an LED name
- update following drivers and their DT bindings to use the new LED
registration API:
- leds-an30259a, leds-gpio, leds-as3645a, leds-aat1290, leds-cr0014114,
leds-lm3601x, leds-lm3692x, leds-lp8860, leds-lt3593, leds-sc27xx-blt
Other LED class improvements:
- replace {devm_}led_classdev_register() macros with inlines
- allow to call led_classdev_unregister() unconditionally
- switch to use fwnode instead of be stuck with OF one
LED triggers improvements:
- led-triggers:
- fix dereferencing of null pointer
- fix a memory leak bug
- ledtrig-gpio:
- GPIO 0 is valid
Drop superseeded apu2/3 support from leds-apu since for apu2+ a newer,
more complete driver exists, based on a generic driver for the AMD
SOCs gpio-controller, supporting LEDs as well other devices:
- drop profile field from priv data
- drop iosize field from priv data
- drop enum_apu_led_platform_types
- drop superseeded apu2/3 led support
- add pr_fmt prefix for better log output
- fix error message on probing failure
Other misc fixes and improvements to existing LED class drivers:
- leds-ns2, leds-max77650:
- add of_node_put() before return
- leds-pwm, leds-is31fl32xx:
- use struct_size() helper
- leds-lm3697, leds-lm36274, leds-lm3532:
- switch to use fwnode_property_count_uXX()
- leds-lm3532:
- fix brightness control for i2c mode
- change the define for the fs current register
- fixes for the driver for stability
- add full scale current configuration
- dt: Add property for full scale current.
- avoid potentially unpaired regulator calls
- move static keyword to the front of declarations
- fix optional led-max-microamp prop error handling
- leds-max77650:
- add of_node_put() before return
- add MODULE_ALIAS()
- Switch to fwnode property API
- leds-as3645a:
- fix misuse of strlcpy
- leds-netxbig:
- add of_node_put() in netxbig_leds_get_of_pdata()
- remove legacy board-file support
- leds-is31fl319x:
- simplify getting the adapter of a client
- leds-ti-lmu-common:
- fix coccinelle issue
- move static keyword to the front of declaration
- leds-syscon:
- use resource managed variant of device register
- leds-ktd2692:
- fix a typo in the name of a constant
- leds-lp5562:
- allow firmware files up to the maximum length
- leds-an30259a:
- fix typo
- leds-pca953x:
- include the right header"
* tag 'leds-for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds: (72 commits)
leds: lm3532: Fix optional led-max-microamp prop error handling
led: triggers: Fix dereferencing of null pointer
leds: ti-lmu-common: Move static keyword to the front of declaration
leds: lm3532: Move static keyword to the front of declarations
leds: trigger: gpio: GPIO 0 is valid
leds: pwm: Use struct_size() helper
leds: is31fl32xx: Use struct_size() helper
leds: ti-lmu-common: Fix coccinelle issue in TI LMU
leds: lm3532: Avoid potentially unpaired regulator calls
leds: syscon: Use resource managed variant of device register
leds: Replace {devm_}led_classdev_register() macros with inlines
leds: Allow to call led_classdev_unregister() unconditionally
leds: lm3532: Add full scale current configuration
dt: lm3532: Add property for full scale current.
leds: lm3532: Fixes for the driver for stability
leds: lm3532: Change the define for the fs current register
leds: lm3532: Fix brightness control for i2c mode
leds: Switch to use fwnode instead of be stuck with OF one
leds: max77650: Switch to fwnode property API
led: triggers: Fix a memory leak bug
...
The email address listed in MODULE_AUTHOR() will be disabled in the
near future. Replace it with my private one.
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20190818093345.29647-6-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some Amlogic boards store the Ethernet MAC address inside the eFuse. The
Ethernet MAC address uses 6 bytes. The existing logic in
meson_mx_efuse_read() would write beyond the end of the data buffer when
trying to read data with a size that is not aligned to word_size (4
bytes on Meson8, Meson8b and Meson8m2).
Calculate the remaining data to copy inside meson_mx_efuse_read() so
reading 6 bytes doesn't write beyond the end of the data buffer.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20190818093345.29647-5-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Like in H3, A64 SID controller doesn't return correct data
when using direct access. It appears that on A64, SID needs
8 bytes of word_size.
Workaround is to enable read by registers.
Signed-off-by: Stefan Mavrodiev <stefan@olimex.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Tested-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20190818093345.29647-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i.MX8MN is a new SoC of i.MX8M series, it is similar to i.MX8MM
in terms of addressing and clock setup, add support for its fuse
read/write.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20190818093345.29647-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The compatibility "eeprom" attribute is currently root-only no
matter what the configuration says. The "nvmem" attribute does
respect the setting of the root_only configuration bit, so do the
same for "eeprom".
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: b6c217ab9b ("nvmem: Add backwards compatibility support for older EEPROM drivers.")
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20190728184255.563332e6@endymion
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the "big" driver core and debugfs changes for 5.3-rc1
It's a lot of different patches, all across the tree due to some api
changes and lots of debugfs cleanups. Because of this, there is going
to be some merge issues with your tree at the moment, I'll follow up
with the expected resolutions to make it easier for you.
Other than the debugfs cleanups, in this set of changes we have:
- bus iteration function cleanups (will cause build warnings
with s390 and coresight drivers in your tree)
- scripts/get_abi.pl tool to display and parse Documentation/ABI
entries in a simple way
- cleanups to Documenatation/ABI/ entries to make them parse
easier due to typos and other minor things
- default_attrs use for some ktype users
- driver model documentation file conversions to .rst
- compressed firmware file loading
- deferred probe fixes
All of these have been in linux-next for a while, with a bunch of merge
issues that Stephen has been patient with me for. Other than the merge
issues, functionality is working properly in linux-next :)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCXSgpnQ8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ykcwgCfS30OR4JmwZydWGJ7zK/cHqk+KjsAnjOxjC1K
LpRyb3zX29oChFaZkc5a
=XrEZ
-----END PGP SIGNATURE-----
Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core and debugfs updates from Greg KH:
"Here is the "big" driver core and debugfs changes for 5.3-rc1
It's a lot of different patches, all across the tree due to some api
changes and lots of debugfs cleanups.
Other than the debugfs cleanups, in this set of changes we have:
- bus iteration function cleanups
- scripts/get_abi.pl tool to display and parse Documentation/ABI
entries in a simple way
- cleanups to Documenatation/ABI/ entries to make them parse easier
due to typos and other minor things
- default_attrs use for some ktype users
- driver model documentation file conversions to .rst
- compressed firmware file loading
- deferred probe fixes
All of these have been in linux-next for a while, with a bunch of
merge issues that Stephen has been patient with me for"
* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
debugfs: make error message a bit more verbose
orangefs: fix build warning from debugfs cleanup patch
ubifs: fix build warning after debugfs cleanup patch
driver: core: Allow subsystems to continue deferring probe
drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
arch_topology: Remove error messages on out-of-memory conditions
lib: notifier-error-inject: no need to check return value of debugfs_create functions
swiotlb: no need to check return value of debugfs_create functions
ceph: no need to check return value of debugfs_create functions
sunrpc: no need to check return value of debugfs_create functions
ubifs: no need to check return value of debugfs_create functions
orangefs: no need to check return value of debugfs_create functions
nfsd: no need to check return value of debugfs_create functions
lib: 842: no need to check return value of debugfs_create functions
debugfs: provide pr_fmt() macro
debugfs: log errors when something goes wrong
drivers: s390/cio: Fix compilation warning about const qualifiers
drivers: Add generic helper to match by of_node
driver_find_device: Unify the match function with class_find_device()
bus_find_device: Unify the match callback with class_find_device
...
According to NXP Reference Manuals and uboot/atf sources the OCOTP block
on imx8m behaves more like imx6 than imx7.
- Fuses can be read/written 32bits at a time (no imx7-like banking)
- The OCOTP_HW_OCOTP_TIMING register is like imx6 not imx7
Since nvmem doesn't support uboot-style "sense" and "override" this
issue only affected "write" which is very rarely used.
Fixes: 163c0dbd0cb1 ("nvmem: imx-ocotp: add support for imx8mq")
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds support to burn the fuses on the i.MX8MM.
https://www.nxp.com/webapp/Download?colCode=IMX8MMRM
The i.MX8MM is similar to i.MX6 processors in terms of addressing and clock
setup.
The documentation specifies 60 discreet OTP registers but, the fusemap
address space encompasses up to 256 registers. We map the entire putative
256 OTP registers.
Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The RELAX field of the OCOTP block is turning out as a zero on i.MX8MM.
This messes up the subsequent re-load of the fuse shadow registers.
After some discussion with people @ NXP its clear we have missed a trick
here in Linux.
The OCOTP fuse programming time has a physical minimum 'burn time' that is
not related to the ipg_clk.
We need to define the RELAX, STROBE_READ and STROBE_PROG fields in terms of
desired timings to allow for the burn-in to safely complete. Right now only
the RELAX field is calculated in terms of an absolute time and we are
ending up with a value of zero.
This patch inherits the u-boot timings for the OCOTP_TIMING calculation on
the i.MX6 and i.MX8. Those timings are known to work and critically specify
values such as STROBE_PROG as a minimum timing.
Fixes: 0642bac7da ("nvmem: imx-ocotp: add write support")
Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Suggested-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The i.MX6 and i.MX8 both have a bit-field spanning bits 27:22 called the
WAIT field.
The WAIT field according to the documentation for both parts "specifies
time interval between auto read and write access in one time program. It is
given in number of ipg_clk periods."
This patch ensures that the relevant field is read and written back to the
timing register.
Fixes: 0642bac7da ("nvmem: imx-ocotp: add write support")
Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Reviewed-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i.MX6 defines OCOTP_CTRLn:ADDR as seven bit address-field with a one bit
RSVD0 field, i.MX7 defines OCOTP_CTRLn:ADDR as a four bit address-field
with a four bit RSVD0 field.
i.MX8 defines the OCOTP_CTRLn:ADDR bit-field as a full range eight bits.
i.MX6 and i.MX7 should return zero for their respective RSVD0 bits and
ignore a write-back of zero where i.MX8 will make use of the full range.
This patch expands the bit-field definition for all users to eight bits,
which is safe due to RSVD0 being a no-op for the i.MX6 and i.MX7.
Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Reviewed-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
The SNVS LPGR IP block is also found on other i.MX SoCs that
are not covered by the current SOC_IMX6 || SOC_IMX7D logic.
One example is the i.MX7ULP.
To avoid keep expanding the SoC logic selection, make it broader
by using the more generic ARCH_MXC symbol instead.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation http www opensource org
licenses gpl license html http www gnu org copyleft gpl html
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 3 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081201.897982733@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of version 2 of the gnu general public license as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 64 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.894819585@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 and
only version 2 as published by the free software foundation this
program is distributed in the hope that it will be useful but
without any warranty without even the implied warranty of
merchantability or fitness for a particular purpose see the gnu
general public license for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 294 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.825281744@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 655 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 3 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [kishon] [vijay] [abraham]
[i] [kishon]@[ti] [com] this program is distributed in the hope that
it will be useful but without any warranty without even the implied
warranty of merchantability or fitness for a particular purpose see
the gnu general public license for more details
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [graeme] [gregory]
[gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
[kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
[hk] [hemahk]@[ti] [com] this program is distributed in the hope
that it will be useful but without any warranty without even the
implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 1105 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Various driver updates for platforms and a couple of the small driver
subsystems we merge through our tree:
Among the larger pieces:
- Power management improvements for TI am335x and am437x (RTC suspend/wake)
- Misc new additions for Amlogic (socinfo updates)
- ZynqMP FPGA manager
- Nvidia improvements for reset/powergate handling
- PMIC wrapper for Mediatek MT8516
- Misc fixes/improvements for ARM SCMI, TEE, NXP i.MX SCU drivers
-----BEGIN PGP SIGNATURE-----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=YSfu
-----END PGP SIGNATURE-----
Merge tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull ARM SoC-related driver updates from Olof Johansson:
"Various driver updates for platforms and a couple of the small driver
subsystems we merge through our tree:
Among the larger pieces:
- Power management improvements for TI am335x and am437x (RTC
suspend/wake)
- Misc new additions for Amlogic (socinfo updates)
- ZynqMP FPGA manager
- Nvidia improvements for reset/powergate handling
- PMIC wrapper for Mediatek MT8516
- Misc fixes/improvements for ARM SCMI, TEE, NXP i.MX SCU drivers"
* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (57 commits)
soc: aspeed: fix Kconfig
soc: add aspeed folder and misc drivers
spi: zynqmp: Fix build break
soc: imx: Add generic i.MX8 SoC driver
MAINTAINERS: Update email for Qualcomm SoC maintainer
memory: tegra: Fix a typos for "fdcdwr2" mc client
Revert "ARM: tegra: Restore memory arbitration on resume from LP1 on Tegra30+"
memory: tegra: Replace readl-writel with mc_readl-mc_writel
memory: tegra: Fix integer overflow on tick value calculation
memory: tegra: Fix missed registers values latching
ARM: tegra: cpuidle: Handle tick broadcasting within cpuidle core on Tegra20/30
optee: allow to work without static shared memory
soc/tegra: pmc: Move powergate initialisation to probe
soc/tegra: pmc: Remove reset sysfs entries on error
soc/tegra: pmc: Fix reset sources and levels
soc: amlogic: meson-gx-pwrc-vpu: Add support for G12A
soc: amlogic: meson-gx-pwrc-vpu: Fix power on/off register bitmask
fpga manager: Adding FPGA Manager support for Xilinx zynqmp
dt-bindings: fpga: Add bindings for ZynqMP fpga driver
firmware: xilinx: Add fpga API's
...
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>
Add support for H6's SID controller. It supports 4K-bit
EFUSE, bigger than before.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the new helper devm_platform_ioremap_resource() which wraps the
platform_get_resource() and devm_ioremap_resource() together, to
simplify the code.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the new helper devm_platform_ioremap_resource() which wraps the
platform_get_resource() and devm_ioremap_resource() together, to
simplify the code.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the new helper devm_platform_ioremap_resource() which wraps the
platform_get_resource() and devm_ioremap_resource() together, to
simplify the code.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
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>
On STM32MP15, OTP area may be read/written by using BSEC (boot, security
and OTP control). BSEC registers set is composed of various regions, among
which control registers and OTP shadow registers.
Secure monitor calls are involved in this process to allow (or deny)
access to the full range of OTP data.
This adds support for reading and writing OTP data using SMC services.
Data content can be aligned on 16-bits or 8-bits. Then take care of it,
since BSEC data is 32-bits wide.
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>
The device tree binding already lists compatible strings for these two
SoCs. They don't have the defect as seen on the H3, and the size and
register layout is the same as the A64. Furthermore, the driver does
not include nvmem cell definitions.
Add support for these two compatible strings, re-using the config for
the A64.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Originally the SID e-fuses were thought to be in big-endian format.
Later sources show that they are in fact native or little-endian.
The most compelling evidence is the thermal sensor calibration data,
which is a set of one to three 16-bit values. In native-endian they
are in 16-bit cells with increasing offsets, whereas with big-endian
they are in the wrong order, and a gap with no data will show if there
are one or three cells.
Switch to a native endian representation for the nvmem device. For the
H3, the register read-out method was already returning data in native
endian. This only affects the other SoCs.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sunxi_sid driver currently uses a statically allocated nvmem_config
structure that is updated at probe time. This is sub-optimal as it
limits the driver to one instance, and also takes up space even if the
device is not present.
Modify the driver to allocate the nvmem_config structure at probe time,
plugging in the desired parameters along the way.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SID cells are 32-bit aligned, and a multiple of 32 bits in length. The
only outlier is the thermal sensor calibration data, which is 16 bits
per sensor. However a whole 64 bits is allocated for this purpose, so
we could consider it conforming to the rule above.
Also, the register read-out method assumes native endian, unlike the
direct MMIO method, which assumes big endian. Thus no endian conversion
is involved.
Under these assumptions, the register read-out method can be slightly
optimized. Instead of reading one word then discarding 3 bytes, read
the whole word directly into the buffer. However, for reads under 4
bytes or trailing bytes, we still use a scratch buffer to extract the
requested bytes.
We could go one step further if .word_size was 4, but changing that
would affect the sysfs interface's behavior.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
