linux-stable.git/drivers/nvmem/core.c, branch linux-5.6.y

nvmem: release the write-protect pin

2020-04-08T07:11:07+00:00

commit a9c3766cb19cdadf2776aba41b64470002645894 upstream.

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 
Signed-off-by: Khouloud Touil 
Cc: stable 
[Bartosz: tweak the commit message]
Signed-off-by: Bartosz Golaszewski 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20200310132257.23358-8-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman

Merge branch 'i2c/for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

2020-02-07T20:54:13+00:00

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
  ...

nvmem: core: fix memory abort in cleanup path

2020-01-10T12:52:13+00:00

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 
Cc: stable 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20200109104017.6249-5-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman

nvmem: fix a 'makes pointer from integer without a cast' build warning

2020-01-10T11:11:30+00:00

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 
Fixes: 2a127da461a9 ("nvmem: add support for the write-protect pin")
Signed-off-by: Bartosz Golaszewski 
Acked-by: Srinivas Kandagatla

nvmem: add support for the write-protect pin

2020-01-09T09:48:54+00:00

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 
Reviewed-by: Linus Walleij 
Acked-by: Srinivas Kandagatla 
Signed-off-by: Bartosz Golaszewski

nvmem: core: add nvmem_device_find

2019-10-07T16:47:37+00:00

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 
Acked-by: Srinivas Kandagatla 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Paul Burton 
Cc: Jonathan Corbet 
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: Lee Jones 
Cc: David S. Miller 
Cc: Alessandro Zummo 
Cc: Alexandre Belloni 
Cc: Greg Kroah-Hartman 
Cc: Jiri Slaby 
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

drivers: Introduce device lookup variants by of_node

2019-07-30T11:07:41+00:00

Introduce wrappers for {bus/driver/class}_find_device() to
locate devices by its of_node.

Cc: Maarten Lankhorst 
Cc: Maxime Ripard 
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie 
Cc: Daniel Vetter 
Cc: devicetree@vger.kernel.org
Cc: Florian Fainelli 
Cc: Frank Rowand 
Cc: Heiko Stuebner 
Cc: Liam Girdwood 
Cc: linux-i2c@vger.kernel.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-spi@vger.kernel.org
Cc: Mathieu Poirier 
Cc: Rob Herring 
Cc: Srinivas Kandagatla 
Cc: Takashi Iwai 
Cc: Alan Tull 
Cc: linux-fpga@vger.kernel.org
Cc: Peter Rosin 
Cc: Florian Fainelli 
Cc: Heiner Kallweit 
Cc: "David S. Miller" 
Cc: Andrew Lunn 
Cc: Liam Girdwood 
Cc: "Rafael J. Wysocki" 
Cc: Thor Thayer 
Cc: Jiri Slaby 
Cc: Andrew Lunn 
Cc: Peter Rosin 
Signed-off-by: Suzuki K Poulose 
Acked-by: Lee Jones 
Acked-by: Wolfram Sang  # I2C part
Acked-by: Moritz Fischer  # For FPGA part
Acked-by: Mark Brown 
Link: https://lore.kernel.org/r/20190723221838.12024-3-suzuki.poulose@arm.com
Signed-off-by: Greg Kroah-Hartman

bus_find_device: Unify the match callback with class_find_device

2019-06-24T03:22:31+00:00

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 
Cc: Andrew Lunn 
Cc: Andreas Noever 
Cc: Arnd Bergmann 
Cc: Bjorn Helgaas 
Cc: Corey Minyard 
Cc: Christian Borntraeger 
Cc: David Kershner 
Cc: "David S. Miller" 
Cc: David Airlie 
Cc: Felipe Balbi 
Cc: Frank Rowand 
Cc: Grygorii Strashko 
Cc: Harald Freudenberger 
Cc: Hartmut Knaack 
Cc: Heiko Stuebner 
Cc: Jason Gunthorpe 
Cc: Jonathan Cameron 
Cc: "James E.J. Bottomley" 
Cc: Len Brown 
Cc: Mark Brown 
Cc: Michael Ellerman 
Cc: Michael Jamet 
Cc: "Martin K. Petersen" 
Cc: Peter Oberparleiter 
Cc: Sebastian Ott 
Cc: Srinivas Kandagatla 
Cc: Yehezkel Bernat 
Cc: rafael@kernel.org
Acked-by: Corey Minyard 
Acked-by: David Kershner 
Acked-by: Mark Brown 
Acked-by: Rafael J. Wysocki 
Acked-by: Srinivas Kandagatla 
Acked-by: Wolfram Sang  # for the I2C parts
Acked-by: Rob Herring 
Signed-off-by: Suzuki K Poulose 
Signed-off-by: Greg Kroah-Hartman

nvmem: core: add NVMEM_SYSFS Kconfig

2019-04-25T17:44:33+00:00

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 
Reviewed-by: Mika Westerberg 
Reviewed-by: Gaurav Kohli 
Tested-by: Gaurav Kohli 
Signed-off-by: Greg Kroah-Hartman

nvmem: core: fix read buffer in place

2019-04-25T17:43:12+00:00

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 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman