linux-stable.git/drivers/nvmem/core.c, branch v5.4

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

nvmem: core: add nvmem_cell_read_u16

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

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

nvmem: core: don't check the return value of notifier chain call

2019-02-19T13:50:11+00:00

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

nvmem: core: Avoid useless iterations in nvmem_cell_get_from_lookup()

2019-01-31T15:24:15+00:00

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

nvmem: core: Fix device reference leak

2019-01-31T15:24:15+00:00

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

nvmem: core: Always reference the device returned by nvmem_device_get()

2019-01-31T15:24:14+00:00

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

nvmem: core: Properly handle connection ID in of_nvmem_device_get()

2019-01-31T15:24:14+00:00

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