User:Knuxify/Draft:Qualcomm/Adding a new SoC to mainline Linux: Difference between revisions

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 In order to begin mainlining your SoC, you need to have the following bits of information:
-* The '''downstream codename''' ("DTS nickname"?) of your SoC. If you're lucky, it's probably already somewhere out there online. You'll find it in the driver names on the device. This will be useful when looking things up in the downstream kernel, as it primarily uses the codename, whereas mainline uses the model number.
+* The '''codenames''' of the SoC. Qualcomm SoCs appear to have two codenames<ref>The names of these codenames have been sourced from [https://wiki.postmarketos.org/wiki/Qualcomm_Snapdragon_8_Gen_1/8%2B_Gen_1/7%2B_Gen_2_(SM8450/SM8475/SM7475) the postmarketOS wiki page for the Snapdragon 8 Gen 1], not sure where that is sourced from.</ref>:
-* The '''internal codename''' of your SoC. Around mid-2025, Qualcomm's mainline Linux engineers decided that instead of using the model name for SoC drivers, they should use the codename instead... except the codename in downstream isn't always the same as the ''actual'' codename.
+** '''Board codename''' ("DTS nickname"?) - you'll find it in the driver names on the device, as well as in the main compatible string of the devicetree. This is what's used across most of the downstream kernel.
-** ''Mere mortals'' shall not know these codenames... but you can probably ask your friendly neighborhood sympathizer of the mainline cause<ref>https://lore.kernel.org/lkml/[email protected]/</ref>.
+** '''Platform codename''' - presumably shared between multiple SoCs from the same family.
-** Sometimes the downstream codename matches with the internal name (as might be the case for "waipio" given it's mentioned alongside the others in [https://mysupport.qualcomm.com/supportforums/s/question/0D54V00007gUfXASA0/whats-the-difference-of-v69-and-v73 this random Qualcomm support forums post]), othertimes it's different (SM7435 uses "parrot" in the kernel but is actually called "netrani"<ref>https://lore.kernel.org/lkml/[email protected]/</ref>).
+** Since SM7635 ("Volcano"/"Milos") getting upstreamed, Qualcomm appears to have changed their policy around driver/compatible naming in mainline and now expects developers to use the platform codename instead of the model number<ref>https://lore.kernel.org/lkml/[email protected]/</ref>. If you're unsure of the platform codename for your device, you can send the Qualcomm folks an email and ask them directly<ref>I ended up getting [https://lore.kernel.org/lkml/[email protected]/ a public reply to my query for SM7435].</ref>, or just use the model name for now and let them correct you (as was done in the Milos case).
 * A copy of the '''downstream kernel'''; preferably the one for your device, but you can also use the kernel from another device with the same SoC, or - as a last resort - any kernel with the relevant SoC drivers (hint: search by downstream codename).
 * A copy of the '''<code>qcom_proprietary_devicetree</code>''' or similar repo with the DTSI source files (because they're not in the kernel repo for whatever reason...). Search for <code>(downstream codename).dtsi</code> on GitHub and you'll find the right repository eventually.