From: Benoit HOUYERE <benoit.houyere@st.com> To: Alexander Steffen <Alexander.Steffen@infineon.com>, "Eyal.Cohen@nuvoton.com" <Eyal.Cohen@nuvoton.com>, "jarkko.sakkinen@linux.intel.com" <jarkko.sakkinen@linux.intel.com>, "tmaimon77@gmail.com" <tmaimon77@gmail.com> Cc: "oshrialkoby85@gmail.com" <oshrialkoby85@gmail.com>, "robh+dt@kernel.org" <robh+dt@kernel.org>, "mark.rutland@arm.com" <mark.rutland@arm.com>, "peterhuewe@gmx.de" <peterhuewe@gmx.de>, "jgg@ziepe.ca" <jgg@ziepe.ca>, "arnd@arndb.de" <arnd@arndb.de>, "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>, "oshri.alkoby@nuvoton.com" <oshri.alkoby@nuvoton.com>, "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-integrity@vger.kernel.org" <linux-integrity@vger.kernel.org>, "gcwilson@us.ibm.com" <gcwilson@us.ibm.com>, "kgoldman@us.ibm.com" <kgoldman@us.ibm.com>, "nayna@linux.vnet.ibm.com" <nayna@linux.vnet.ibm.com>, "Dan.Morav@nuvoton.com" <Dan.Morav@nuvoton.com>, "oren.tanami@nuvoton.com" <oren.tanami@nuvoton.com>, "Christophe Ricard (christophe.ricard@gmail.com)" <christophe.ricard@gmail.com>, Elena WILLIS <elena.willis@st.com>, "Olivier COLLART" <olivier.collart@st.com> Subject: RE: [PATCH v2 0/2] char: tpm: add new driver for tpm i2c ptp Date: Tue, 30 Jul 2019 08:39:35 +0000 [thread overview] Message-ID: <2e86f1b6a3c04c9889d0f12f4eb079d4@SFHDAG3NODE3.st.com> (raw) In-Reply-To: <548d3727-4a8f-38d4-2193-8a09cbae1e64@infineon.com> Hi Alexander, Jarkko and Eyal, A first I2C TCG patch (tpm_tis_i2c.c) has been proposed in the same time as tpm_tis_spi.c by Christophe 3 years ago. https://patchwork.kernel.org/patch/8628681/ At the time, we have had two concerns : 1) I2C TPM component number, in the market, compliant with new I2C TCG specification to validate new I2C driver. 2) Lots changing was already provided by tpm_tis_spi.c on 4.8. That's why Tpm_tis_i2c.c has been postponed. Tpm_tis_spi Linux driver is now robust, if we have several different I2C TPM solutions today to validate a tpm_tis_i2c driver, I 'm ready to contribute to it for validation (STmicro TPM) or propose a solution compatible on 5.1 linux driver if needed under timeframe proposed (second half of august). Best Regards, Benoit -----Original Message----- From: linux-integrity-owner@vger.kernel.org <linux-integrity-owner@vger.kernel.org> On Behalf Of Alexander Steffen Sent: jeudi 18 juillet 2019 19:10 To: Eyal.Cohen@nuvoton.com; jarkko.sakkinen@linux.intel.com; tmaimon77@gmail.com Cc: oshrialkoby85@gmail.com; robh+dt@kernel.org; mark.rutland@arm.com; peterhuewe@gmx.de; jgg@ziepe.ca; arnd@arndb.de; gregkh@linuxfoundation.org; oshri.alkoby@nuvoton.com; devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; linux-integrity@vger.kernel.org; gcwilson@us.ibm.com; kgoldman@us.ibm.com; nayna@linux.vnet.ibm.com; Dan.Morav@nuvoton.com; oren.tanami@nuvoton.com Subject: Re: [PATCH v2 0/2] char: tpm: add new driver for tpm i2c ptp On 18.07.2019 14:51, Eyal.Cohen@nuvoton.com wrote: > Hi Jarkko and Alexander, > > We have made an additional code review on the TPM TIS core driver, it looks quite good and we can connect our new I2C driver to this layer. Great :) In the meantime, I've done some experiments creating an I2C driver based on tpm_tis_core, see https://patchwork.kernel.org/patch/11049363/ Please have a look at that and provide your feedback (and/or use it as a basis for further implementations). > However, there are several differences between the SPI interface and the I2C interface that will require changes to the TIS core. > At a minimum we thought of: > 1. Handling TPM Localities in I2C is different It turned out not to be that different in the end, see the code mentioned above and my comment here: https://patchwork.kernel.org/cover/11049365/ > 2. Handling I2C CRC - relevant only to I2C bus hence not supported > today by TIS core That is completely optional, so there is no need to implement it in the beginning. Also, do you expect a huge benefit from that functionality? Are bit flips that much more likely on I2C compared to SPI, which has no CRC at all, but still works fine? > 3. Handling Chip specific issues, since I2C implementation might be > slightly different across the various TPM vendors Right, that seems similar to the cr50 issues (https://lkml.org/lkml/2019/7/17/677), so there should probably be a similar way to do it. > 4. Modify tpm_tis_send_data and tpm_tis_recv_data to work according > the TCG Device Driver Guide (optimization on TPM_STS access and > send/recv retry) Optimizations are always welcome, but I'd expect basic communication to work already with the current code (though maybe not as efficiently as possible). > Besides this, during development we might encounter additional differences between SPI and I2C. > > We currently target to allocate an eng. to work on this on the second half of August with a goal to have the driver ready for the next kernel merge window. > > Regards, > Eyal.
WARNING: multiple messages have this Message-ID (diff)
From: Benoit HOUYERE <benoit.houyere@st.com> To: Alexander Steffen <Alexander.Steffen@infineon.com>, "Eyal.Cohen@nuvoton.com" <Eyal.Cohen@nuvoton.com>, "jarkko.sakkinen@linux.intel.com" <jarkko.sakkinen@linux.intel.com>, "tmaimon77@gmail.com" <tmaimon77@gmail.com> Cc: "oshrialkoby85@gmail.com" <oshrialkoby85@gmail.com>, "robh+dt@kernel.org" <robh+dt@kernel.org>, "mark.rutland@arm.com" <mark.rutland@arm.com>, "peterhuewe@gmx.de" <peterhuewe@gmx.de>, "jgg@ziepe.ca" <jgg@ziepe.ca>, "arnd@arndb.de" <arnd@arndb.de>, "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>, "oshri.alkoby@nuvoton.com" <oshri.alkoby@nuvoton.com>, "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-integrity@vger.kernel.org" <linux-integrity@vger.kernel.org>, "gcwilson@us.ibm.com" <gcwilson@us.ibm.com>, "kgoldman@us.ibm.com" <kgoldman@us.ibm.com>, "nayna@linux.vnet.ibm.com" <nayna@linux.vnet.ibm.com>, "Dan.Morav@nuvoton.com" <Dan.Morav@nuvoton.com>, "oren.tanami@nuvoton.com" <oren.tanam> Subject: RE: [PATCH v2 0/2] char: tpm: add new driver for tpm i2c ptp Date: Tue, 30 Jul 2019 08:39:35 +0000 [thread overview] Message-ID: <2e86f1b6a3c04c9889d0f12f4eb079d4@SFHDAG3NODE3.st.com> (raw) In-Reply-To: <548d3727-4a8f-38d4-2193-8a09cbae1e64@infineon.com> Hi Alexander, Jarkko and Eyal, A first I2C TCG patch (tpm_tis_i2c.c) has been proposed in the same time as tpm_tis_spi.c by Christophe 3 years ago. https://patchwork.kernel.org/patch/8628681/ At the time, we have had two concerns : 1) I2C TPM component number, in the market, compliant with new I2C TCG specification to validate new I2C driver. 2) Lots changing was already provided by tpm_tis_spi.c on 4.8. That's why Tpm_tis_i2c.c has been postponed. Tpm_tis_spi Linux driver is now robust, if we have several different I2C TPM solutions today to validate a tpm_tis_i2c driver, I 'm ready to contribute to it for validation (STmicro TPM) or propose a solution compatible on 5.1 linux driver if needed under timeframe proposed (second half of august). Best Regards, Benoit -----Original Message----- From: linux-integrity-owner@vger.kernel.org <linux-integrity-owner@vger.kernel.org> On Behalf Of Alexander Steffen Sent: jeudi 18 juillet 2019 19:10 To: Eyal.Cohen@nuvoton.com; jarkko.sakkinen@linux.intel.com; tmaimon77@gmail.com Cc: oshrialkoby85@gmail.com; robh+dt@kernel.org; mark.rutland@arm.com; peterhuewe@gmx.de; jgg@ziepe.ca; arnd@arndb.de; gregkh@linuxfoundation.org; oshri.alkoby@nuvoton.com; devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; linux-integrity@vger.kernel.org; gcwilson@us.ibm.com; kgoldman@us.ibm.com; nayna@linux.vnet.ibm.com; Dan.Morav@nuvoton.com; oren.tanami@nuvoton.com Subject: Re: [PATCH v2 0/2] char: tpm: add new driver for tpm i2c ptp On 18.07.2019 14:51, Eyal.Cohen@nuvoton.com wrote: > Hi Jarkko and Alexander, > > We have made an additional code review on the TPM TIS core driver, it looks quite good and we can connect our new I2C driver to this layer. Great :) In the meantime, I've done some experiments creating an I2C driver based on tpm_tis_core, see https://patchwork.kernel.org/patch/11049363/ Please have a look at that and provide your feedback (and/or use it as a basis for further implementations). > However, there are several differences between the SPI interface and the I2C interface that will require changes to the TIS core. > At a minimum we thought of: > 1. Handling TPM Localities in I2C is different It turned out not to be that different in the end, see the code mentioned above and my comment here: https://patchwork.kernel.org/cover/11049365/ > 2. Handling I2C CRC - relevant only to I2C bus hence not supported > today by TIS core That is completely optional, so there is no need to implement it in the beginning. Also, do you expect a huge benefit from that functionality? Are bit flips that much more likely on I2C compared to SPI, which has no CRC at all, but still works fine? > 3. Handling Chip specific issues, since I2C implementation might be > slightly different across the various TPM vendors Right, that seems similar to the cr50 issues (https://lkml.org/lkml/2019/7/17/677), so there should probably be a similar way to do it. > 4. Modify tpm_tis_send_data and tpm_tis_recv_data to work according > the TCG Device Driver Guide (optimization on TPM_STS access and > send/recv retry) Optimizations are always welcome, but I'd expect basic communication to work already with the current code (though maybe not as efficiently as possible). > Besides this, during development we might encounter additional differences between SPI and I2C. > > We currently target to allocate an eng. to work on this on the second half of August with a goal to have the driver ready for the next kernel merge window. > > Regards, > Eyal.
next prev parent reply other threads:[~2019-07-30 8:41 UTC|newest] Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-06-28 15:13 [PATCH v2 0/2] char: tpm: add new driver for tpm i2c ptp Oshri Alkoby 2019-06-28 15:13 ` [PATCH v2 1/2] dt-bindings: tpm: add the TPM I2C PTP device tree binding documentation Oshri Alkoby 2019-06-28 15:13 ` [PATCH v2 2/2] char: tpm: add new driver for tpm i2c ptp Oshri Alkoby 2019-07-04 8:43 ` [PATCH v2 0/2] " Jarkko Sakkinen 2019-07-04 11:29 ` Alexander Steffen 2019-07-04 11:29 ` Alexander Steffen 2019-07-04 17:48 ` Oshri Alkobi 2019-07-05 11:28 ` Jarkko Sakkinen [not found] ` <6e7ff1b958d84f6e8e585fd3273ef295@NTILML02.nuvoton.com> 2019-07-15 8:08 ` Tomer Maimon 2019-07-15 9:45 ` Jarkko Sakkinen 2019-07-15 9:45 ` Jarkko Sakkinen 2019-07-18 12:51 ` Eyal.Cohen 2019-07-18 12:51 ` Eyal.Cohen 2019-07-18 12:51 ` Eyal.Cohen 2019-07-18 17:10 ` Alexander Steffen 2019-07-18 17:10 ` Alexander Steffen 2019-07-30 8:39 ` Benoit HOUYERE [this message] 2019-07-30 8:39 ` Benoit HOUYERE 2019-07-30 17:42 ` Alexander Steffen 2019-07-30 17:42 ` Alexander Steffen 2019-09-06 12:16 ` Benoit HOUYERE 2019-09-06 12:16 ` Benoit HOUYERE 2019-08-15 17:03 ` Oshri Alkobi 2019-08-16 16:12 ` Alexander Steffen 2019-08-16 16:12 ` Alexander Steffen 2019-08-25 11:25 ` Oshri Alkobi 2019-07-17 7:48 ` Alexander Steffen 2019-07-17 7:48 ` Alexander Steffen 2019-07-05 11:15 ` Jarkko Sakkinen
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