Hi everyone, sorry for being late to the party. I just noticed this discussion while reading [1]. Am Dienstag, 4. Juni 2024, 09:42:31 CEST schrieb Michael Walle: > These devices are more like an AT25 compatible EEPROM instead of > flashes. Like an EEPROM the user doesn't need to explicitly erase the > memory, nor are there sectors or pages. Thus, instead of the SPI-NOR > (flash) driver, one should instead use the at25 EEPROM driver. > > Signed-off-by: Michael Walle <mwalle@xxxxxxxxxx> > Cc: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> > Cc: Thorsten Scherer <t.scherer@xxxxxxxxxxxx> > Cc: Marek Vasut <marex@xxxxxxx> > Cc: Imre Kaloz <kaloz@xxxxxxxxxxx> > Cc: Andrew Lunn <andrew@xxxxxxx> > Cc: Flavio Suligoi <f.suligoi@xxxxxxx> > --- > The referenced binding only supports the true AT25 compatible EEPROMs > where you have to specify additional properties like size and page size > or cypress FRAM devices where all the properties are discovered by the > driver. I don't have the actual hardware, therefore I can't work on a > proper driver and binding. But I really want to deprecate the use of > these EEPROM like devices in SPI-NOR. So as a first step, mark the > devices in the DT bindings as deprecated. > > There are three in-tree users of this. I hope I've CCed all the relevant > people. With the switch to the at25 driver also comes a user-space > facing change: there is no more MTD device. Instead there is an "eeprom" > file in /sys now, just like for every other EEPROM. > > Marek already expressed, that the sps1 dts can likely be removed > altogether. I'd like to hear from the other board DTS maintainers if > they seem some problems moving to the EEPROM interface - or maybe that > device isn't used at all anyway. So in the end, we can hopefully move > all the users over to the at25 driver. So instead of spi-nor you want to use at25 for this MRAM devices? AFAICS at25 is a spi only driver, but spi-nor is a spi-mem driver. So I am wondering if at25 driver is capable of using QSPI hosts. Everspin EMxxLXB devices are capable of running in xSPI modes. Regarding QSPI (DSPI/OSPI as well) I assumed spi-nor is a given, but maybe I am completely wrong here. Maybe someone could clarify this. Best regards, Alexander [1] https://lore.kernel.org/linux-kernel/20240405100104.480779-1-f.suligoi@xxxxxxx/ > --- > Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml > index 6e3afb42926e..2dccb6b049ea 100644 > --- a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml > +++ b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml > @@ -21,7 +21,6 @@ properties: > (m25p(40|80|16|32|64|128)|\ > n25q(32b|064|128a11|128a13|256a|512a|164k)))|\ > atmel,at25df(321a|641|081a)|\ > - everspin,mr25h(10|40|128|256)|\ > (mxicy|macronix),mx25l(4005a|1606e|6405d|8005|12805d|25635e)|\ > (mxicy|macronix),mx25u(4033|4035)|\ > (spansion,)?s25fl(128s|256s1|512s|008k|064k|164k)|\ > @@ -42,6 +41,14 @@ properties: > - spansion,s25fs512s > - const: jedec,spi-nor > - const: jedec,spi-nor > + > + # Deprecated bindings > + - items: > + - pattern: "^everspin,mr25h(10|40|128|256)$" > + - const: jedec,spi-nor > + description: > + Deprecated binding, use Documentation/devicetree/bindings/eeprom/at25.yaml. > + deprecated: true > description: > SPI NOR flashes compatible with the JEDEC SFDP standard or which may be > identified with the READ ID opcode (0x9F) do not deserve a specific > -- TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany Amtsgericht München, HRB 105018 Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider http://www.tq-group.com/
