Add support for SPD5118 compatible chips with 16-bit addressing enabled
which are connected to I2C controllers.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
I3C uses 16-bit register addresses. Setting the page through the legacy
mode access pointer in the legacy mode device configuration register (MR11)
is not needed. This is similar to 16-bit addressing in legacy mode.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The Renesas/IDT SPD5118 Hub Controller is known to take the specification
literally and does not permit access to volatile registers except for the
page register if the selected page is non-zero. Explicitly name the chip
to ensure that the information does not get lost.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Make use of the new generic helper for calculating the parity.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Link: https://lore.kernel.org/r/20250107090204.6593-3-wsa+renesas@sang-engineering.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
These drivers don't use the driver_data member of struct i2c_device_id,
so don't explicitly initialize this member.
This prepares putting driver_data in an anonymous union which requires
either no initialization or named designators. But it's also a nice
cleanup on its own.
While touching these structs, also remove commas after the sentinel
entries and use a consistent indention style.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Message-ID: <20240918123150.1540161-7-u.kleine-koenig@baylibre.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The SPD5118 specification says, in its documentation of the page bits
in the MR11 register:
"
This register only applies to non-volatile memory (1024) Bytes) access of
SPD5 Hub device.
For volatile memory access, this register must be programmed to '000'.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
"
Renesas/ITD SPD5118 hub controllers take this literally and disable access
to volatile memory if the page selected in MR11 is != 0. Since the BIOS or
ROMMON will access the non-volatile memory and likely select a page != 0,
this means that the driver will not instantiate since it can not identify
the chip. Even if the driver instantiates, access to volatile registers
is blocked after a nvram read operation which selects a page other than 0.
To solve the problem, add initialization code to select page 0 during
probe. Before doing that, use basic validation to ensure that this is
really a SPD5118 device and not some random EEPROM.
Cc: Sasha Kozachuk <skozachuk@google.com>
Cc: John Hamrick <johnham@google.com>
Cc: Chris Sarra <chrissarra@google.com>
Tested-by: Armin Wolf <W_Armin@gmx.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Using regmap for paging significantly improves caching since the regmap
cache no longer needs to be cleared after changing the page, so let's
use it.
Suggested-by: Armin Wolf <W_Armin@gmx.de>
Tested-by: Armin Wolf <W_Armin@gmx.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
With SPD5118 chip detection for the most part handled by the i2c-smbus
core using DMI information, the spd5118 driver no longer needs to
auto-detect spd5118 compliant chips.
Auto-detection by the driver is still needed on systems with no DMI support
or on systems with more than eight DIMMs and can not be removed entirely.
However, it affects boot time and introduces the risk of mis-identifying
chips. Add configuration option to be able to disable it on systems where
chip detection is handled outside the driver.
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Armin Wolf <W_Armin@gmx.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Add support for reading SPD NVMEM data from SPD5118 (Jedec JESD300)
compliant memory modules. NVMEM write operation is not supported.
NVMEM support is optional. If CONFIG_NVMEM is disabled, the driver will
still instantiate but not provide NVMEM attribute files.
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Armin Wolf <W_Armin@gmx.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Add suspend/resume support to ensure that limit and configuration
registers are updated and synchronized after a suspend/resume cycle.
Cc: Armin Wolf <W_Armin@gmx.de>
Cc: Stephen Horvath <s.horvath@outlook.com.au>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Stephen Horvath <s.horvath@outlook.com.au>
Tested-by: Armin Wolf <W_Armin@gmx.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Add support for SPD5118 (Jedec JESD300) compliant temperature
sensors. Such sensors are typically found on DDR5 memory modules.
Cc: René Rebe <rene@exactcode.de>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Stephen Horvath <s.horvath@outlook.com.au>
Tested-by: Armin Wolf <W_Armin@gmx.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
