linux-toradex.git/drivers/nvmem/core.c, branch v4.19

Merge 4.18-rc5 into char-misc-next

2018-07-16T07:04:54+00:00

We want the char-misc fixes in here as well.

Signed-off-by: Greg Kroah-Hartman

nvmem: core: remove unused nvmem_device ncells member

2018-07-07T15:30:46+00:00

nvmem ncells can be over written by calling nvmem_add_cells()
multiple times. I see there is no real point of maintaining count
of cells when we have a list of cell.

Remove this to avoid any confusion!

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

nvmem: Don't let a NULL cell_id for nvmem_cell_get() crash us

2018-07-07T15:30:25+00:00

In commit ca04d9d3e1b1 ("phy: qcom-qusb2: New driver for QUSB2 PHY on
Qcom chips") you can see a call like:

  devm_nvmem_cell_get(dev, NULL);

Note that the cell ID passed to the function is NULL.  This is because
the qcom-qusb2 driver is expected to work only on systems where the
PHY node is hooked up via device-tree and is nameless.

This works OK for the most part.  The first thing nvmem_cell_get()
does is to call of_nvmem_cell_get() and there it's documented that a
NULL name is fine.  The problem happens when the call to
of_nvmem_cell_get() returns -EINVAL.  In such a case we'll fall back
to nvmem_cell_get_from_list() and eventually might (if nvmem_cells
isn't an empty list) crash with something that looks like:

 strcmp
 nvmem_find_cell
 __nvmem_device_get
 nvmem_cell_get_from_list
 nvmem_cell_get
 devm_nvmem_cell_get
 qusb2_phy_probe

There are several different ways we could fix this problem:

One could argue that perhaps the qcom-qusb2 driver should be changed
to use of_nvmem_cell_get() which is allowed to have a NULL name.  In
that case, we'd need to add a patche to introduce
devm_of_nvmem_cell_get() since the qcom-qusb2 driver is using devm
managed resources.

One could also argue that perhaps we could just add a name to
qcom-qusb2.  That would be OK but I believe it effectively changes the
device tree bindings, so maybe it's a no-go.

In this patch I have chosen to fix the problem by simply not crashing
when a NULL cell_id is passed to nvmem_cell_get().

NOTE: that for the qcom-qusb2 driver the "nvmem-cells" property is
defined to be optional and thus it's expected to be a common case that
we would hit this crash and this is more than just a theoretical fix.

Fixes: ca04d9d3e1b1 ("phy: qcom-qusb2: New driver for QUSB2 PHY on Qcom chips")
Signed-off-by: Douglas Anderson 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman

nvmem: properly handle returned value nvmem_reg_read

2018-05-14T14:20:48+00:00

Function nvmem_reg_read can return a non zero value indicating an error.
This returned value must be read and error propagated to
nvmem_cell_prepare_write_buffer. Silence the following gcc warning (W=1):

drivers/nvmem/core.c:1093:9: warning: variable 'rc' set but
 not used [-Wunused-but-set-variable]

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

nvmem: core: describe add missing dev function parameter

2018-05-14T14:20:48+00:00

Document dev parameter which not described in devm_nvmem_unregister
and devm_nvmem_register functions.

Fix below warnings when kernel is compiled with W=1
drivers/nvmem/core.c:579: warning: Function parameter or member
 'dev' not described in 'devm_nvmem_register'
nvmem/core.c:615: warning: Function parameter or member 'dev'
 not described in 'devm_nvmem_unregister'

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

drivers: nvmem: Export nvmem_add_cells()

2018-05-14T14:20:48+00:00

Not all platforms use device tree. It is useful to be able to add
cells to a NVMEM device from code. Export nvmem_add_cells() so making
this possible.

This required changing the parameters a bit, so that just the cells
and the number of cells are passed, not the whole nvmem config
structure.

Signed-off-by: Andrew Lunn 
Reviewed-by: Andrey Smirnov 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman

nvmem: Introduce devm_nvmem_(un)register()

2018-03-14T18:28:13+00:00

Introduce devm_nvmem_register()/devm_nvmem_unregister() to make
.remove() unnecessary in trivial drivers.

Cc: Srinivas Kandagatla 
Cc: Heiko Stuebner 
Cc: Masahiro Yamada 
Cc: Carlo Caione 
Cc: Kevin Hilman 
Cc: Matthias Brugger 
Cc: cphealy@gmail.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-amlogic@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Andrey Smirnov 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman

nvmem: core: Allow specifying device name verbatim

2018-03-14T18:28:13+00:00

Add code to allow avoid having nvmem core append a numeric suffix to
the end of the name by passing config->id of -1.

Cc: Srinivas Kandagatla 
Cc: Heiko Stuebner 
Cc: Masahiro Yamada 
Cc: Carlo Caione 
Cc: Kevin Hilman 
Cc: Matthias Brugger 
Cc: cphealy@gmail.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-amlogic@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Andrey Smirnov 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman

nvmem: core: switch to device_property_present for reading property "read-only"

2017-12-19T09:39:33+00:00

Switch to more generic device_property_present to consider also non-DT
properties.

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

nvmem: core: let stride and word_size default to 1

2017-12-19T09:39:33+00:00

If the caller doesn't set stride and/or word_size in struct nvmem_config
then nvmem_register accepts this but we may face strange effects later
due to both values being 0. Therefore use 1 as default for both values.

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