commit 25e5ef302c24a6fead369c0cfe88c073d7b97ca8 upstream.

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: 57d155506dd5 ("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>
[Bartosz: backported the patch to older branches]
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 37cf28d3b5bca1b532a0b6aac722e7f2788a9294 upstream.

Works with ST M24M02.

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

commit 7f6d2ecd3d7acaf205ea7b3e96f9ffc55b92298b upstream.

Trying to read the MAC address from an eeprom that has an offset that
is not a multiple of 4 causes an error currently.

Fix it by changing the nvmem stride to 1.

Signed-off-by: David Lechner <david@lechnology.com>
[Bartosz: tweaked the commit message]
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit d9bcd462daf34aebb8de9ad7f76de0198bb5a0f0 upstream.

So far we completely rely on the caller to provide valid arguments.
To be on the safe side perform an own sanity check.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 5478e478eee3b096b8d998d4ed445da30da2dfbc upstream.

There's an ilog2() expansion in AT24_DEVICE_MAGIC() which rounds down
the actual size of EUI-48 byte array in at24mac402 eeproms to 4 from 6,
making it impossible to read it all.

Fix it by manually adjusting the value in probe().

This patch contains a temporary fix that is suitable for stable
branches. Eventually we'll probably remove the call to ilog2() while
converting the magic values to actual structs.

Fixes: 0b813658c115 ("eeprom: at24: add support for at24mac series")
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 644a1f19c6c8393d0c4168a5adf79056da6822eb upstream.

Chip datasheet mentions that word addresses other than the actual
start position of the MAC delivers undefined results. So fix this.
Current implementation doesn't work due to this wrong offset.

Fixes: 0b813658c115 ("eeprom: at24: add support for at24mac series")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull i2c updates from Wolfram Sang:
 "Here is the 4.9 pull request from I2C including:

   - centralized error messages when registering to the core
   - improved lockdep annotations to prevent false positives
   - DT support for muxes, gates, and arbitrators
   - bus speeds can now be obtained from ACPI
   - i2c-octeon got refactored and now supports ThunderX SoCs, too
   - i2c-tegra and i2c-designware got a bigger bunch of updates
   - a couple of standard driver fixes and improvements"

* 'i2c/for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (71 commits)
  i2c: axxia: disable clks in case of failure in probe
  i2c: octeon: thunderx: Limit register access retries
  i2c: uniphier-f: fix misdetection of incomplete STOP condition
  gpio: pca953x: variable 'id' was used twice
  i2c: i801: Add support for Kaby Lake PCH-H
  gpio: pca953x: fix an incorrect lockdep warning
  i2c: add a warning to i2c_adapter_depth()
  lockdep: make MAX_LOCKDEP_SUBCLASSES unconditionally visible
  i2c: export i2c_adapter_depth()
  i2c: rk3x: Fix variable 'min_total_ns' unused warning
  i2c: rk3x: Fix sparse warning
  i2c / ACPI: Do not touch an I2C device if it belongs to another adapter
  i2c: octeon: Fix high-level controller status check
  i2c: octeon: Avoid sending STOP during recovery
  i2c: octeon: Fix set SCL recovery function
  i2c: rcar: add support for r8a7796 (R-Car M3-W)
  i2c: imx: make bus recovery through pinctrl optional
  i2c: meson: add gxbb compatible string
  i2c: uniphier-f: set the adapter to master mode when probing
  i2c: uniphier-f: avoid WARN_ON() of clk_disable() in failure path
  ...

The patch does the following:
- fixes specifiers and removes explicit casting of the parameters
- joins literals to one line
- increases readability of the parameters

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The at24 driver doesn't check if the chip is functional in its probe
function. This leads to instantiating devices that are not physically
present. For example the cape EEPROMs for BeagleBone Black are defined
in the device tree at four addresses on i2c2, but normally only one of
them is present.

If the userspace doesn't know the location in advance, it will need to
check if reading the nvmem attributes fails to determine which EEPROM
is actually there.

Try to read a single byte in probe() and bail-out with -ENODEV if the
read fails.

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

loop_until_timeout() replaced a do {} while loop in the at24 driver
with a for loop which, under certain circumstances (such as heavy load
or low value of the write_timeout argument), can lead to the code in
the loop never being executed.

Make sure that at least one iteration of the code enclosed within
loop_until_timeout() is always executed.

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