Hi Miquel, On Thu, Sep 14, 2023 at 10:59 AM Miquel Raynal <miquel.raynal@xxxxxxxxxxx> wrote: > geert@xxxxxxxxxxxxxx wrote on Thu, 14 Sep 2023 10:34:50 +0200: > > On Thu, Sep 14, 2023 at 10:08 AM Krzysztof Kozlowski > > <krzysztof.kozlowski@xxxxxxxxxx> wrote: > > > On 30/08/2023 17:18, Biju Das wrote: > > > >>> regmap_update_bits(rpc->regmap, RPCIF_CMNCR, @@ -774,6 > > > >>> +776,12 @@ static int rpcif_probe(struct platform_device *pdev) > > > >>> return ret; > > > >>> } > > > >>> > > > >>> + if (rpc->info->type == RPCIF_RZ_G2L && > > > >> > > > >> Wouldn't this apply to non-RZ/G2L systems, too? > > > > > > > > It applies, if the device uses the flash[1] or [2] and it needs > > > > 4-bit tx support. > > > > > > > > [1] Figure 20: QUAD INPUT/OUTPUT FAST READ – EBh/ECh > > > > https://media-www.micron.com/-/media/client/global/documents/products/data-sheet/nor-flash/serial-nor/mt25q/die-rev-a/mt25q_qlks_u_512_aba_0.pdf?rev=3e5b2a574f7b4790b6e58dacf4c889b2 > > > > > > > > [2] section 8.14 > > > > > > > > https://www.renesas.com/eu/en/document/dst/at25ql128a-datasheet?r=1608586 > > > > > > Geert, > > > > > > Does it answer your comment or do you expect here some changes? > > > > Well, now it has been confirmed this applies to non-RZ/G2L systems, too, > > the check for RPCIF_RZ_G2L should probably be removed. In upstream, > > only arch/arm64/boot/dts/renesas/rzg2l{,c}-smarc-som.dtsi have devices > > that are compatible with "micron,mt25qu512a", but obviously they can > > appear elsewhere, too. > > > > Now, the presence of that compatible value in rzg2l{,c}-smarc-som.dtsi > > currently causes a dtbs_check warning, as it is not documented. > > However, there has been some pushback against adding more compatible > > values, cfr. my patch to add mt25qu512a[1], and Miquel's commit [2]. > > Just FYI, I sent [2] after an unsuccessful attempt to update that list > too, see [3]. The idea is: if you don't have anything useful to add, Oh, I didn't know that. > just use the generic compatible. If you need specific changes, you can > add an entry. The problem is that usually these things are discovered too late, so the only prudent way is to be proactive, and always add them. Initially I thought that the different handling on RZ/G2L was due to a difference in the RPC-IF block. But now we know it's due to the type of FLASH attached. > [3] https://lore.kernel.org/linux-mtd/d816499e-baab-6200-0780-17a8205b252e@xxxxxxxxxx/ > > > But the issue Biju is seeing proves there is a need to add these. > > > > In addition, I had hoped to gather some feedback or guidance from the > > hyperbus and/or spi people, as issues w.r.t. pin states will eventually > > pop up on other systems, too, and thus may need handling in the core, > > instead of in each individual device driver. But of course that can > > be done later, when the need arises. > > > > Thanks! > > > > [1] "[PATCH] dt-bindings: mtd: jedec,spi-nor: Document support for > > more MT25QU parts" > > https://lore.kernel.org/all/363186079b4269891073f620e3e2353cf7d2559a.1669988238.git.geert+renesas@xxxxxxxxx > > [2] 4b0cb4e7ab2f777c ("dt-bindings: mtd: spi-nor: clarify the need for > > spi-nor compatibles"). -- Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
