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path: root/drivers/misc/eeprom/at24.c
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2018-12-10eeprom: at24: add support for 24c2048Adrian Bunk
Works with ST M24M02. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2018-10-02eeprom: at24: fix unexpected timeout under high loadWang Xin
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>
2018-07-25eeprom: at24: Add support for address-width propertyAlan Chiang
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>
2018-05-16eeprom: at24: provide a separate routine for creating dummy i2c clientsBartosz Golaszewski
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>
2018-05-16eeprom: at24: provide and use a helper for releasing dummy i2c clientsBartosz Golaszewski
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>
2018-05-16eeprom: at24: use devm_nvmem_register()Bartosz Golaszewski
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>
2018-05-16eeprom: at24: fix retrieving the at24_chip_data structureBartosz Golaszewski
Commit feb2f19b1e8f ("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: feb2f19b1e8f ("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>
2018-03-23eeprom: at24: use SPDX identifier instead of GPL boiler-plateBartosz Golaszewski
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>
2018-03-23eeprom: at24: simplify the i2c functionality checkingBartosz Golaszewski
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>
2018-03-23eeprom: at24: fix a line breakBartosz Golaszewski
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>
2018-03-23eeprom: at24: tweak newlinesBartosz Golaszewski
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>
2018-03-23eeprom: at24: refactor at24_probe()Bartosz Golaszewski
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>
2018-03-23eeprom: at24: remove at24_platform_data from at24_dataBartosz Golaszewski
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>
2018-03-23eeprom: at24: move platform data processing into a separate routineBartosz Golaszewski
This driver can receive its device data from different sources depending on the system. Move the entire code processing platform data, device tree and acpi into a separate function. 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>
2018-03-23eeprom: at24: switch to using probe_new() from the i2c frameworkBartosz Golaszewski
Use the new probe() style for i2c drivers. 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>
2018-03-23eeprom: at24: provide and use at24_base_client_dev()Bartosz Golaszewski
Use a helper function for accessing the device struct of the base i2c client. This routine is named in a way that reflects its purpose unlike the previously hand-coded dereferencing. 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>
2018-03-23eeprom: at24: readability tweak in at24_probe()Bartosz Golaszewski
Use a helper variable for the size we want to allocate with devm_kzalloc() and save an ugly line break. 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>
2018-03-23eeprom: at24: use a helper variable for devBartosz Golaszewski
We use the &client->dev construct all over in at24_probe(). Use a helper variable which is more readable and allows to avoid a couple unnecessary line breaks. 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>
2018-03-23eeprom: at24: rename chip to pdata in at24_probe()Bartosz Golaszewski
Reflect the purpose of this variable: it contains platform data so name it such. 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>
2018-03-23eeprom: at24: rename at24_get_pdata()Bartosz Golaszewski
As preparation for at24_probe() refactoring: rename at24_get_pdata() to at24_properties_to_pdata(). We're doing it because we'll move the pdata parsing code into a separate function which will be called at24_get_pdata(). Current routine with that name actually parses the device properties so change its name to reflect its purpose. 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>
2018-03-23eeprom: at24: don't check if byte_len is a power of 2Bartosz Golaszewski
We support certain models the size of which is not a power of 2. This is not a reason to emit a warning. 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>
2018-03-23eeprom: at24: make struct initialization uniform in at24_probe()Bartosz Golaszewski
When zeroing structs, use "{ }" everywhere. 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>
2018-03-23eeprom: at24: drop redundant variable in at24_write()Bartosz Golaszewski
We can reuse ret instead of defining a loop-local status variable. 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>
2018-03-23eeprom: at24: drop redundant variable in at24_read()Bartosz Golaszewski
We can reuse ret instead of defining a loop-local status variable. 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>
2018-03-23eeprom: at24: remove code separatorsBartosz Golaszewski
These are just two left-overs from times when this driver was bigger. They are not really useful anymore. Remove them. 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>
2018-03-23eeprom: at24: arrange local variablesBartosz Golaszewski
Arrange declarations of local variables by line length as visually it's easier to read. 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>
2018-03-23eeprom: at24: remove nvmem_config from at24_dataBartosz Golaszewski
This structure only needs to exist during the call to nvmem_register(). 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>
2018-03-23eeprom: at24: disable regmap lockingBartosz Golaszewski
We use our own mutex for locking. Disable the regmap-specific locking. 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>
2018-01-02eeprom: at24: extend the list of chips supported in DTBartosz Golaszewski
Add all supported at24 variants to the of_match table. Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
2018-01-01eeprom: at24: add support for the write-protect pinBartosz Golaszewski
AT24 EEPROMs have a write-protect pin, which - when pulled high - inhibits writes to the upper quadrant of memory (although it has been observed that on some chips it disables writing to the entire memory range). On some boards, this pin is connected to a GPIO and pulled high by default, which forces the user to manually change its state before writing. On linux this means that we either need to hog the line all the time, or set the GPIO value before writing from outside of the at24 driver. Make the driver check if the write-protect GPIO was defined in the device tree and pull it low whenever writing to the EEPROM. Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
2018-01-01eeprom: at24: remove temporary fix for at24mac402 sizeSven Van Asbroeck
The chip size passed via devicetree, i2c, or acpi device ids is now no longer limited to a power of two. So the temporary fix can be removed. Signed-off-by: Sven Van Asbroeck <svendev@arcx.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2018-01-01eeprom: at24: convert magic numbers to structsSven Van Asbroeck
Fundamental properties such as capacity and page size differ among at24-type chips. But these chips do not have an id register, so this can't be discovered at runtime. Traditionally, at24-type eeprom properties were determined in two ways: - by passing a 'struct at24_platform_data' via platform_data, or - by naming the chip type in the devicetree, which passes a 'magic number' to probe(), which is then converted to a 'struct at24_platform_data'. Recently a bug was discovered because the magic number rounds down all chip sizes to the lowest power of two. This was addressed by a work-around commit 5478e478eee3 ("eeprom: at24: correctly set the size for at24mac402"), with the wish that magic numbers should over time be converted to structs. This patch replaces the magic numbers with 'struct at24_chip_data'. Signed-off-by: Sven Van Asbroeck <svendev@arcx.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2018-01-01eeprom: at24: code shrinkBartosz Golaszewski
A regmap_config struct is pretty big and declaring two of them statically just to tweak the reg_bits value adds unnecessary bloat. Declare the regmap config locally in at24_probe() instead. Bloat-o-meter output for ARM: add/remove: 0/2 grow/shrink: 1/0 up/down: 4/-272 (-268) Function old new delta at24_probe 1560 1564 +4 regmap_config_8 136 - -136 regmap_config_16 136 - -136 Total: Before=7012, After=6744, chg -3.82% Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2018-01-01eeprom: at24: use a common prefix for all symbols in at24.cBartosz Golaszewski
There are a couple symbols defined in the driver source file which are missing the at24_ prefix. This patch fixes that. For module params: use module_param_named() in order to not break userspace. Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2018-01-01eeprom: at24: fix coding style issuesBartosz Golaszewski
Fix issues reported by checkpatch for at24.c. Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2018-01-01eeprom: at24: support eeproms that do not auto-rollover readsSven Van Asbroeck
Some multi-address eeproms in the at24 family may not automatically roll-over reads to the next slave address. On those eeproms, reads that straddle slave boundaries will not work correctly. Solution: Mark such eeproms with a flag that prevents reads straddling slave boundaries. Add the AT24_FLAG_NO_RDROL flag to the eeprom entry in the device_id table, or add 'no-read-rollover' to the eeprom devicetree entry. Note that I have not personally enountered an at24 chip that does not support read rollovers. They may or may not exist. However, my hardware requires this functionality because of a quirk. Signed-off-by: Sven Van Asbroeck <svendev@arcx.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2018-01-01eeprom: at24: remove now unneeded smbus-related codeHeiner Kallweit
Remove remaining now unneeded code dealing with SMBUS details. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2018-01-01eeprom: at24: remove old read functionsHeiner Kallweit
Remove the old and now unused read functions. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2018-01-01eeprom: at24: add regmap-based read functionHeiner Kallweit
Add regmap-based read function and instead of using three different read functions (standard, mac, serial) use just one and factor out the read offset adjustment for mac and serial to at24_adjust_read_offset. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2018-01-01eeprom: at24: remove old write functionsHeiner Kallweit
Remove the old and now unused write functions. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2018-01-01eeprom: at24: add regmap-based write functionHeiner Kallweit
Add a regmap-based write function. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2018-01-01eeprom: at24: change at24_translate_offset return typeHeiner Kallweit
Change return type of at24_translate_offset to *at24_client to make member regmap accessible for subsequent patches of this series. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2018-01-01eeprom: at24: add basic regmap_i2c supportHeiner Kallweit
This patch adds basic regmap support to be used by subsequent patches of this series. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2017-12-06eeprom: at24: change nvmem stride to 1David Lechner
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. Cc: stable@vger.kernel.org Signed-off-by: David Lechner <david@lechnology.com> [Bartosz: tweaked the commit message] Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2017-12-03eeprom: at24: fix I2C device selection for runtime PMSakari Ailus
The at24 driver creates dummy I2C devices to access offsets in the chip that are outside the area supported using a single I2C address. It is not meaningful to use runtime PM to such devices; the system firmware (ACPI) does not know about these devices nor runtime PM was enabled for them. Always use the real device instead of the dummy ones. Fixes: 98e8201039af ("eeprom: at24: enable runtime pm support") Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Tested-by: Sven Van Asbroeck on a 24AA16/24LC16B <svendev@arcx.com> [Bartosz: rebased on top of previous fixes for 4.15, tweaked the commit message] [Sven: fixed Bartosz's rebase] Signed-off-by: Sven Van Asbroeck <svendev@arcx.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2017-11-29eeprom: at24: check at24_read/write argumentsHeiner Kallweit
So far we completely rely on the caller to provide valid arguments. To be on the safe side perform an own sanity check. Cc: stable@vger.kernel.org Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2017-11-29eeprom: at24: fix reading from 24MAC402/24MAC602Heiner Kallweit
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. Cc: stable@vger.kernel.org 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>
2017-11-29eeprom: at24: correctly set the size for at24mac402Bartosz Golaszewski
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. Cc: stable@vger.kernel.org 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>
2017-11-05eeprom: at24: Add OF device ID tableJavier Martinez Canillas
The driver doesn't have a struct of_device_id table but supported devices are registered via Device Trees. This is working on the assumption that a I2C device registered via OF will always match a legacy I2C device ID and that the MODALIAS reported will always be of the form i2c:<device>. But this could change in the future so the correct approach is to have an OF device ID table if the devices are registered via OF. To maintain backward compatibility with old Device Trees, only use the OF device ID table .data if the device was registered via OF and the OF node compatible matches an entry in the OF device ID table. Suggested-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-10-17eeprom: at24: enable runtime pm supportDivagar Mohandass
Currently the device is kept in D0, there is an opportunity to save power by enabling runtime pm. Device can be daisy chained from PMIC and we can't rely on I2C core for auto resume/suspend. Driver will decide when to resume/suspend. Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Divagar Mohandass <divagar.mohandass@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>