We need to append device id even if eeprom have a label property set as some
platform can have multiple eeproms with same label and we can not register
each of those with same label. Failing to register those eeproms trigger
cascade failures on such platform (system is no longer working).

This fix regression on such platform introduced with 4e302c3b



Reported-by: Alexander Fomichev <fomichev.ru@gmail.com>
Fixes: 4e302c3b

 ("misc: eeprom: at24: fix NVMEM name with custom AT24 device name")
Cc: stable@vger.kernel.org
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

cd5676db ("misc: eeprom: at24: support pm_runtime control") disables
regulator in runtime suspend. If runtime suspend is called before
regulator disable, it will results in regulator unbalanced disabling.

Fixes: cd5676db

 ("misc: eeprom: at24: support pm_runtime control")
Cc: stable <stable@vger.kernel.org>
Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Link: https://lore.kernel.org/r/20210420133050.377209-1-hsinyi@chromium.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When the "label" property is set on the AT24 EEPROM the NVMEM devid is
set to NVMEM_DEVID_NONE, but it is not effective since there is a
leftover line setting it back to NVMEM_DEVID_AUTO a few lines after.

Fixes: 61f764c3

 ("eeprom: at24: Support custom device names for AT24 EEPROMs")
Signed-off-by: Diego Santa Cruz <Diego.SantaCruz@spinetix.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

By using the label property, a more descriptive name can be populated
for AT24 EEPROMs NVMEM device. Update the AT24 driver to check to see
if the label property is present and if so, use this as the name for
NVMEM device. Please note that when the 'label' property is present for
the AT24 EEPROM, we do not want the NVMEM driver to append the 'devid'
to the name and so the nvmem_config.id is initialised to
NVMEM_DEVID_NONE.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The AT24 EEPROM driver does not initialise the 'id' field of the
nvmem_config structure and because the entire structure is not
initialised, it ends up with a random value. This causes the NVMEM
driver to append the device 'devid' value to name of the NVMEM
device. Ideally for I2C devices such as the AT24 that already have a
unique name, we would not bother to append the 'devid'. However, given
that this has always been done for AT24 devices, we cannot remove the
'devid' as this will change the name of the userspace sysfs node for
the NVMEM device. Nonetheless we should ensure that the 'id' field of
the nvmem_config structure is initialised so that there is no chance of
a random value causes problems in the future. Therefore, set the NVMEM
config.id to NVMEM_DEVID_AUTO for AT24 EEPROMs so that the 'devid' is
always appended.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Set type as NVMEM_TYPE_EEPROM to expose this info via
sysfs:

$ cat /sys/bus/nvmem/devices/{DEVICE}/type
EEPROM

Signed-off-by: Vadym Kochan <vadym.kochan@plvision.eu>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

During nvmem_register() the nvmem core sends notifications when:

    - cell added
    - nvmem added

and during these notifications some callback func may access the nvmem
device, which will fail in case of at24 eeprom because regulator and pm
are enabled after nvmem_register().

Fixes: cd5676db ("misc: eeprom: at24: support pm_runtime control")
Fixes: b20eb4c1

 ("eeprom: at24: drop unnecessary label")
Cc: stable@vger.kernel.org
Signed-off-by: Vadym Kochan <vadym.kochan@plvision.eu>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The elegant code in at24_read() has the drawback that we now need
to make a copy of all parameters to pass them to the post-processing
callback function if there is one. Rewrite the loop in such a way that
the parameters are not modified, so saving them is no longer needed.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Special handling of the Sony VAIO EEPROMs is the last feature of the
legacy eeprom driver that the at24 driver does not support. Adding
this would let us deprecate and eventually remove the legacy eeprom
driver.

So add the option to specify a post-processing callback function that
is called after reading data from the EEPROM, before it is returned
to the user. The 24c02-vaio type is the first use case of that option:
the callback function will mask the sensitive data for non-root users
exactly as the legacy eeprom driver was doing.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[Bartosz: removed a stray newline]
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

... as is the case when !CONFIG_ACPI.

Fixes the following W=1 kernel build warning:

 drivers/misc/eeprom/at24.c:228:36: warning: ‘at24_acpi_ids’ defined but not used [-Wunused-const-variable=]

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20200701093616.GX1179328@dell


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The at24 driver attempts to read a byte from the device to validate that
it's actually present, and if not, disables the vcc regulator and
returns -ENODEV. However, between the read and the error handling path,
pm_runtime_idle() is called and invokes the driver's suspend callback,
which also disables the vcc regulator. This leads to an underflow of the
regulator enable count if the EEPROM is not present.

Move the pm_runtime_suspend() call to be after the error handling path
to resolve this.

Fixes: cd5676db

 ("misc: eeprom: at24: support pm_runtime control")
Signed-off-by: Michael Auchter <michael.auchter@ni.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

This ID is used at leas on some variants of MSC C6B-SLH board.

Signed-off-by: Markus Pietrek <mpie@msc-ge.com>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Although in the most platforms, the power of eeprom are alway
on, some platforms disable the eeprom power in order to meet
low power request. This patch add the pm_runtime ops to control
power to support all platforms.

Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
[Bartosz: rebased on top of current at24/for-next]
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

NVMEM framework is an interface for the at24 EEPROMs as well as for
other drivers, instead of passing the wp-gpios over the different
drivers each time, it would be better to pass it over the NVMEM
subsystem once and for all.

Removing the support for the write-protect pin after adding it to the
NVMEM subsystem.

Signed-off-by: Khouloud Touil <ktouil@baylibre.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

For consistency and easier maintenance: sort the headers alphabetically.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The current GPL v2.0 or later SPDX tag is 'GPL-2.0-or-later' as defined
at https://spdx.org/licenses/

.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Currently when binding to an spd EEPROM, the at24 drivers logs the
following message:

256 byte spd EEPROM, read-only, 0 bytes/write

The last part is confusing, as by definition you don't write to a
read-only EEPROM, plus "0 bytes/write" makes no sense whatsoever.

I propose to have a different message for read-only EEPROMs, which
does not include this last part.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The integration of the at24 driver into the nvmem framework broke the
world-readability of spd EEPROMs. Fix it.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: stable@vger.kernel.org
Fixes: 57d15550

 ("eeprom: at24: extend driver to plug into the NVMEM framework")
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

We used to have a call to ilog2() in AT24_DEVICE_MAGIC(). That's long
gone so this header is no longer needed.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>

We no longer have platform data in at24, so this comment is invalid.
Make it refer to device tree & properties instead.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    struct boo entry[];
};

size = sizeof(struct foo) + count * sizeof(struct boo);
instance = devm_kzalloc(dev, size, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);

Notice that, in this case, variable at24_size is not necessary, hence it
is removed.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/misc/eeprom/at24.c: In function at24_make_dummy_client:
drivers/misc/eeprom/at24.c:514:21: warning: variable addr set but not used [-Wunused-but-set-variable]

It's not used since commit e7308628

 ("eeprom:
at24: use devm_i2c_new_dummy_device()")

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

If we move the nvmem registration above the pm enable calls and the
test read, we can drop the error label and make the code more readable
as there's now only a single place where we must call
pm_runtime_disable() in error path.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Now that it's upstream, use the resource managed version
of i2c_new_dummy_device().

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

If the device node defines 'num-addresses', let it override the default
behavior.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

There are no more users of at24_platform_data. Remove the relevant
header and modify the driver code to not use it anymore.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Works with ST M24M02.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

Within at24_loop_until_timeout the timestamp used for timeout checking
is recorded after the I2C transfer and sleep_range(). Under high CPU
load either the execution time for I2C transfer or sleep_range() could
actually be larger than the timeout value. Worst case the I2C transfer
is only tried once because the loop will exit due to the timeout
although the EEPROM is now ready.

To fix this issue the timestamp is recorded at the beginning of each
iteration. That is, before I2C transfer and sleep. Then the timeout
is actually checked against the timestamp of the previous iteration.
This makes sure that even if the timeout is reached, there is still one
more chance to try the I2C transfer in case the EEPROM is ready.

Example:

If you have a system which combines high CPU load with repeated EEPROM
writes you will run into the following scenario.

 - System makes a successful regmap_bulk_write() to EEPROM.
 - System wants to perform another write to EEPROM but EEPROM is still
   busy with the last write.
 - Because of high CPU load the usleep_range() will sleep more than
   25 ms (at24_write_timeout).
 - Within the over-long sleeping the EEPROM finished the previous write
   operation and is ready again.
 - at24_loop_until_timeout() will detect timeout and won't try to write.

Signed-off-by: Wang Xin <xin.wang7@cn.bosch.com>
Signed-off-by: Mark Jonas <mark.jonas@de.bosch.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

Provide a flexible way to determine the addressing bits of eeprom.
Pass the addressing bits to driver through address-width property.

Signed-off-by: Alan Chiang <alanx.chiang@intel.com>
Signed-off-by: Andy Yeh <andy.yeh@intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

Move the code responsible for creating the dummy i2c clients used by
chips taking multiple slave addresses to a separate function.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Peter Rosin <peda@axentia.se>

This allows us to drop two opencoded for loops. We also don't need to
check if the i2c client is NULL before calling i2c_unregister_device().

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Peter Rosin <peda@axentia.se>

We now have a managed variant of nvmem_register(). Use it
in at24_probe().

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Peter Rosin <peda@axentia.se>

Commit feb2f19b ("eeprom: at24: move platform data processing into
a separate routine") introduced a bug where we incorrectly retireve the
at24_chip_data structure. Remove the unnecessary ampersand operator.

Fixes: feb2f19b

 ("eeprom: at24: move platform data processing into a separate routine")
Reported-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

Commit feb2f19b ("eeprom: at24: move platform data processing into
a separate routine") introduced a bug where we incorrectly retireve the
at24_chip_data structure. Remove the unnecessary ampersand operator.

Fixes: feb2f19b

 ("eeprom: at24: move platform data processing into a separate routine")
Reported-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

Replace the GPL (or later) header with the SPDX identifier
for GPL-2.0+.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Tested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Save one call and make code prettier by checking the i2c functionality
in the beginning of at24_probe(), saving the relevant values and
reusing them later.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Tested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Align the broken line with the opening parenthesis to stay consistent
with the rest of the driver code.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Tested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove the newline between the nvmem registration and its return value
check. This is consistent with the rest of the driver code.

Add a missing newline between two pdata checks to stay consistent with
all the others.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Tested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The code in at24_probe() is pretty mangled. It can be cleaned up a bit
by doing things one by one.

Let's group the code by logic: parse and verify pdata, initialize the
regmap, allocate and fill the fields of at24_data, allocate dummy i2c
devices, initialize pm & register with nvmem.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Tested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Not all fields from at24_platform_data are needed in at24_data. Let's
keep just the ones we need and not carry the whole platform_data
structure all the time.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Tested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>