eeprom: ee1004: add support for temperature sensor

The EE1004 SPD data structure advertises the presence of a thermal
sensor on a DDR4 module in byte 14, bit 7. Let's use this information
to explicitly instantiate the thermal sensor I2C client instead of
having to rely on class-based I2C probing.

The temp sensor i2c address can be derived from the SPD i2c address,
so we can directly instantiate the device and don't have to probe
for it. If the temp sensor has been instantiated already by other
means (e.g. class-based auto-detection), then the busy-check in
i2c_new_client_device will detect this.

Patch was successfully tested with a Corsair Vengeance RGB PRO
DDR4 module which comes with a thermal sensor.

Link: https://www.spinics.net/lists/linux-i2c/msg65963.html
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/aa063dfb-2a92-40ba-bdab-e972781ae84b@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Add support for multiple i2c busses

There are systems with more than 8 memory slots where the i2c bus for
SPD is multiplexed. i2c_register_spd() isn't used yet on such systems,
but it's planned. So we need to extend ee1004 accordingly.
With this extension a maximum of 8 i2c busses is supported.

I don't have such a system for testing, therefore I just verified
that the driver still works on a system with a single i2c bus.

For the sake of simplicity the extension uses the existing global
mutex to protect access on all busses. This could be improved,
but we support 8 busses only, and SPD data is small and rarely
accessed, so it shouldn't be a problem.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/f1a216a8-e77c-49f2-8838-561349b30ab8@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: Switch i2c drivers back to use .probe()

After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498b5 ("i2c: Switch .probe() to not take an id parameter") convert
back to (the new) .probe() to be able to eventually drop .probe_new() from
struct i2c_driver.

While touching these drivers, fix alignment in apds990x.c and bh1770glc.c.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Link: https://lore.kernel.org/r/20230517220135.170379-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

i2c: Make remove callback return void

The value returned by an i2c driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Crt Mori <cmo@melexis.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/*
Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5
Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio
Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860
Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b
Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes
Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power
Acked-by: Krzysztof Hałasa <khalasa@piap.pl>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

eeprom: ee1004: limit i2c reads to I2C_SMBUS_BLOCK_MAX

Commit effa453168a7 ("i2c: i801: Don't silently correct invalid transfer
size") revealed that ee1004_eeprom_read() did not properly limit how
many bytes to read at once.

In particular, i2c_smbus_read_i2c_block_data_or_emulated() takes the
length to read as an u8. If count == 256 after taking into account the
offset and page boundary, the cast to u8 overflows. And this is common
when user space tries to read the entire EEPROM at once.

To fix it, limit each read to I2C_SMBUS_BLOCK_MAX (32) bytes, already
the maximum length i2c_smbus_read_i2c_block_data_or_emulated() allows.

Fixes: effa453168a7 ("i2c: i801: Don't silently correct invalid transfer size")
Cc: stable@vger.kernel.org
Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jonas Malaco <jonas@protocubo.io>
Link: https://lore.kernel.org/r/20220203165024.47767-1-jonas@protocubo.io
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Remove not needed debug message

If a user is interested in such transfer statistics he can simply
switch on smbus tracing.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/6169f52e-6ede-d7cc-7f8b-cced55b693d0@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Add helper ee1004_cleanup

Factor out the cleanup code to a new helper ee1004_cleanup().

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/9738cbc7-458d-276f-4012-66551f105d90@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Add constant EE1004_NUM_PAGES

Add a constant for the number of pages.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/6167f9c5-995a-03c3-c324-e93e2a6c969b@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Move call to ee1004_set_current_page to ee1004_eeprom_read

Moving the call to ee1004_set_current_page() to ee1004_eeprom_read()
allows to simplify the code.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/2829a131-51e3-8865-462a-564080158b0b@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Improve error handling in ee1004_read

Simplify the error handling and make it better readable. No functional
change intended.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/13ad7b39-e722-d70a-e25b-03d1fb1734a7@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Factor out setting page to ee1004_set_current_page

Factor out setting the page, this makes the code better readable.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/21e0966f-e6c9-045f-b130-bd9fb071f0d7@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Cache current page at initialization of first device only

The value of ee1004_current_page applies to all SPD eeproms connected
to the adapter. Therefore it's sufficient if we set ee1004_current_page
when the first device is added.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/b9240e58-08bb-3d71-7a9c-9a323b470ab6@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Switch to i2c probe_new callback

Switch to the new i2c_driver probe callback version.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/eb5be659-7427-46c5-66c2-b39650e08ea3@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Improve creating dummy devices

i2c_new_dummy_device() calls i2c_new_client_device() that complains
if it fails to create the device. Therefore we don't have to emit an
error message in case of failure. In addition ensure that
ee1004_set_page is only set if creating the device succeeded.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/d38df5ac-6ecb-7d5f-b5c3-39bfc6a1e8a1@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Improve check for SMBUS features

We have to read 512 bytes only, therefore read performance isn't really
a concern. Don't bother the user if i2c block read isn't supported.

For i2c_smbus_read_i2c_block_data_or_emulated() to work it's sufficient
if I2C_FUNC_SMBUS_READ_I2C_BLOCK or I2C_FUNC_SMBUS_READ_BYTE_DATA is
supported. Therefore remove the check for I2C_FUNC_SMBUS_READ_WORD_DATA.

In addition check for I2C_FUNC_SMBUS_WRITE_BYTE (included in
I2C_FUNC_SMBUS_BYTE) which is needed for setting the page.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/840c668e-6310-e933-e50e-5abeaecfb39c@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Remove usage of i2c_adapter_id in adapter comparison

We can compare the adapter pointers directly instead of using
i2c_adapter_id().

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/99a3f94d-e7ca-e01d-6a78-81e109fde086@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Remove not needed check in ee1004_eeprom_read

i2c_smbus_read_i2c_block_data_or_emulated() checks its length argument,
so we don't have to do it. In addition remove the unlikely hint from
the checks, we do i2c reads and therefore are in a slow path.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/eb2a8bff-43ec-c763-a417-9d741e6f0034@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Remove not needed check in ee1004_read

sysfs_kf_bin_read() checks this for us already. In addition
the function works correctly also w/o this check.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/33889bff-3614-4b73-5010-701635e1edab@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Use kobj_to_i2c_client to simplify the code

Switch to helper kobj_to_i2c_client() to simplify the code.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/4ae57f09-b803-6ae3-c734-87e733a56eb8@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Let device core handle attribute eeprom

Instead of creating/removing the attribute ourselves, just declare the
attribute and let the device core handle it. This allows to simplify
the code.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/8a6c77f2-f84a-311b-c2b9-21798f690e4d@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: use module_i2c_driver to simplify the code

Use the module_i2c_driver() macro to make the code smaller
and a bit simpler.

Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Link: https://lore.kernel.org/r/20200918030225.3902750-1-liushixin2@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

misc: eeprom: ee1004: convert to i2c_new_dummy_device

Move from i2c_new_dummy() to i2c_new_dummy_device(), so we now get an
ERRPTR which we use in error handling.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20190722172616.3982-2-wsa+renesas@sang-engineering.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Deal with nack on page selection

Some EE1004 implementations will not properly ack page selection
commands. They still set the page correctly, so there is no actual
error. Deal with this case gracefully by checking the currently
selected page after we receive a nack. If the page is set right then
we can continue.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: ee1004: Move selected page detection to a separate function

No functional change, this is in preparation for future needs.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

eeprom: New ee1004 driver for DDR4 memory

The EEPROMs which hold the SPD data on DDR4 memory modules are no
longer standard AT24C02-compatible EEPROMs. They are 512-byte EEPROMs
which use only 1 I2C address for data access. You need to switch
between the lower page and the upper page of data by sending commands
on the SMBus.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>