From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0FD6C4708F for ; Tue, 1 Jun 2021 09:58:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 96743613AB for ; Tue, 1 Jun 2021 09:58:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232246AbhFAJ7p convert rfc822-to-8bit (ORCPT ); Tue, 1 Jun 2021 05:59:45 -0400 Received: from smtp.asem.it ([151.1.184.197]:53860 "EHLO smtp.asem.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232173AbhFAJ7m (ORCPT ); Tue, 1 Jun 2021 05:59:42 -0400 X-Greylist: delayed 303 seconds by postgrey-1.27 at vger.kernel.org; Tue, 01 Jun 2021 05:59:41 EDT Received: from webmail.asem.it by asem.it (smtp.asem.it) (SecurityGateway 8.0.0) with ESMTP id 83bc53ab63c74599b705a2029c7a2fe7.MSG for ; Tue, 01 Jun 2021 11:52:55 +0200S Received: from ASAS044.asem.intra (172.16.16.44) by ASAS044.asem.intra (172.16.16.44) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Tue, 1 Jun 2021 11:52:55 +0200 Received: from ASAS044.asem.intra ([::1]) by ASAS044.asem.intra ([::1]) with mapi id 15.01.2176.009; Tue, 1 Jun 2021 11:52:55 +0200 From: Flavio Suligoi To: Michael Walle CC: "linux-kernel@vger.kernel.org" , "linux-mtd@lists.infradead.org" , "miquel.raynal@bootlin.com" , "richard@nod.at" , "tudor.ambarus@microchip.com" , "vigneshr@ti.com" , "Pratyush Yadav" Subject: RE: [PATCH v1] mtd: spi-nor: add ACPI support for non-JEDEC SPI-NOR Thread-Topic: [PATCH v1] mtd: spi-nor: add ACPI support for non-JEDEC SPI-NOR Thread-Index: AQHW8/DSQFilXQ1vXUSgmqjMFBEDbqr92CQAgAHUbcA= Date: Tue, 1 Jun 2021 09:52:55 +0000 Message-ID: <67ad7c365fa749209eab5ddae7f8ce80@asem.it> References: <20210126143748.1546187-1-f.suligoi@asem.it> <20210531074424.16086-1-michael@walle.cc> In-Reply-To: <20210531074424.16086-1-michael@walle.cc> Accept-Language: it-IT, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.16.17.208] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-SGHeloLookup-Result: pass smtp.helo=webmail.asem.it (ip=172.16.16.44) X-SGSPF-Result: none (smtp.asem.it) X-SGOP-RefID: str=0001.0A782F24.60B60377.0096,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 (_st=1 _vt=0 _iwf=0) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Michael, ... > > > In a x86 machine, an additional device can be described > > inside the BIOS ACPI tables. > > For example, an I2C GPIO expander, a LED, etc., > > can be successfully declared in ACPI, so that the related > > device driver can start automatically at the boot. > > > > But for the SPI NOR devices, the ACPI description works > > for JEDEC-compatible devices only. > > > > For example, an Everspin MR25H40 MRAM device (non-JEDEC > > compatible), declared using the following table, > > does not work: > > > > Scope (\_SB.SPI1) > > { > > Device (NVR0) > > { > > Name (_HID, "PRP0001") > > Name (_DDN, "Everspin MR25H40 MRAM") > > Name (_CRS, ResourceTemplate () { > > SpiSerialBus ( > > 1, // Chip select > > PolarityLow, // Chip select is active low > > FourWireMode, // Full duplex > > 8, // Bits per word is 8 (byte) > > ControllerInitiated, // Don't care > > 10000000, // 10 MHz > > ClockPolarityLow, // SPI mode 0 ClockPolarityLow > > ClockPhaseFirst, // SPI mode 0 ClockPhaseFirst > > "\\_SB.SPI1", // SPI host controller > > 0, // Must be 0 > > ResourceConsumer, > > , > > ) > > }) > > > > Name (_DSD, Package () { > > ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), > > Package () { > > Package () {"compatible", "mr25h40"}, > > } > > }) > > } > > } > > This isn't the correct compatible string, according to the devicetree > binding [1], there is no compatible = "mr25h40" binding. The correct entry > would be > compatible = "everspin,mr25h40", "jedec,spi-nor"; > > I'm not familiar with ACPI and don't know wether you can specify a list, > nor am I convinced that it will work then. But it should be worth a try. It works on our board with our custom BIOS. I'm currently use this patch for the kernel of our x86 machines. And that's is the only way I've found to describe the mr25h40 MRAM presence in our BIOS. Obviously, it works because of the above ACPI description is built-in inside the custom BIOS of our boards. Note that the mr25h40 is NOT jedec compatible. > > [1] Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml > > > > > To enable the detection of a non-JEDEC device described > > in a BIOS ACPI table, it is necessary to add its id name > > in the spi_nor_of_table structure. > > With this change, all the SPI NOR devices (JEDEC and > > non-JEDEC) can be detected by the kernel (and the above > > example of ACPI table finally works). > > > > Signed-off-by: Flavio Suligoi > > --- > > drivers/mtd/spi-nor/core.c | 13 +++++++++++++ > > 1 file changed, 13 insertions(+) > > > > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c > > index 6ae7d4c2d2b6..b6fb8b15c439 100644 > > --- a/drivers/mtd/spi-nor/core.c > > +++ b/drivers/mtd/spi-nor/core.c > > @@ -3755,6 +3755,19 @@ static const struct of_device_id > spi_nor_of_table[] = { > > * JEDEC READ ID opcode (0x9F). Use this, if possible. > > */ > > { .compatible = "jedec,spi-nor" }, > > + { .compatible = "m25p05-nonjedec" }, > > + { .compatible = "m25p10-nonjedec" }, > > + { .compatible = "m25p20-nonjedec" }, > > + { .compatible = "m25p40-nonjedec" }, > > + { .compatible = "m25p80-nonjedec" }, > > + { .compatible = "m25p16-nonjedec" }, > > + { .compatible = "m25p32-nonjedec" }, > > + { .compatible = "m25p64-nonjedec" }, > > + { .compatible = "m25p128-nonjedec" }, > > + { .compatible = "mr25h128" }, > > + { .compatible = "mr25h256" }, > > + { .compatible = "mr25h10" }, > > + { .compatible = "mr25h40" }, > > { /* sentinel */ }, > > }; > > MODULE_DEVICE_TABLE(of, spi_nor_of_table); > > -- > > 2.25.1 Thank you very much for your suggestions, Flavio