From: Chen-Yu Tsai <wens@csie.org> To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Cc: Andre Przywara <andre.przywara@arm.com>, Vasily Khoruzhick <anarsoul@gmail.com>, Yangtao Li <tiny.windzz@gmail.com>, Jernej Skrabec <jernej.skrabec@gmail.com>, Samuel Holland <samuel@sholland.org>, "Rafael J . Wysocki" <rafael@kernel.org>, Daniel Lezcano <daniel.lezcano@linaro.org>, Zhang Rui <rui.zhang@intel.com>, Lukasz Luba <lukasz.luba@arm.com>, Rob Herring <robh+dt@kernel.org>, Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, Conor Dooley <conor+dt@kernel.org>, Martin Botka <martin.botka@somainline.org>, Bob McChesney <bob@electricworry.net>, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev Subject: Re: [PATCH v3 4/6] thermal: sun8i: add syscon register access code Date: Tue, 28 Nov 2023 17:09:21 +0800 [thread overview] Message-ID: <CAGb2v64Om8xqpgacbXV9Qf0tbV5qDcSOs7gW-uqSh2HD3Hhu3A@mail.gmail.com> (raw) In-Reply-To: <CAGb2v66L+sW-GQ4HvR-rXsG=JTi6vKt-9P-y1=vPqh0e5gKiOg@mail.gmail.com> On Tue, Nov 28, 2023 at 5:02 PM Chen-Yu Tsai <wens@csie.org> wrote: > > On Tue, Nov 28, 2023 at 4:59 PM Chen-Yu Tsai <wens@csie.org> wrote: > > > > On Tue, Nov 28, 2023 at 4:30 PM Krzysztof Kozlowski > > <krzysztof.kozlowski@linaro.org> wrote: > > > > > > On 28/11/2023 08:50, Chen-Yu Tsai wrote: > > > > On Tue, Nov 28, 2023 at 3:43 PM Krzysztof Kozlowski > > > > <krzysztof.kozlowski@linaro.org> wrote: > > > >> > > > >> On 28/11/2023 01:58, Andre Przywara wrote: > > > >>> > > > >>> +static struct regmap *sun8i_ths_get_syscon_regmap(struct device_node *node) > > > >>> +{ > > > >>> + struct device_node *syscon_node; > > > >>> + struct platform_device *syscon_pdev; > > > >>> + struct regmap *regmap = NULL; > > > >>> + > > > >>> + syscon_node = of_parse_phandle(node, "syscon", 0); > > > >> > > > >> Nope. For the 100th time, this cannot be generic. > > > >> > > > >>> + if (!syscon_node) > > > >>> + return ERR_PTR(-ENODEV); > > > >>> + > > > >>> + syscon_pdev = of_find_device_by_node(syscon_node); > > > >>> + if (!syscon_pdev) { > > > >>> + /* platform device might not be probed yet */ > > > >>> + regmap = ERR_PTR(-EPROBE_DEFER); > > > >>> + goto out_put_node; > > > >>> + } > > > >>> + > > > >>> + /* If no regmap is found then the other device driver is at fault */ > > > >>> + regmap = dev_get_regmap(&syscon_pdev->dev, NULL); > > > >>> + if (!regmap) > > > >>> + regmap = ERR_PTR(-EINVAL); > > > >> > > > >> Aren't you open-coding existing API to get regmap from syscon? > > > > > > > > Not really. This is to get a regmap exported by the device. Syscon's regmap > > > > is not tied to the device at all. > > > > > > I am talking about open-coding existing API. Look at syscon.h. > > > > The underlying implementation is different. > > > > syscon maintains its own mapping of device nodes to regmaps, and creates > > regmaps when none exist. The regmap is not tied to any struct device. > > syscon basically exists outside of the driver model and one has no control > > over what is exposed because it is meant for blocks that are a collection > > of random stuff. > > My bad. I failed to realize there is a platform device driver for syscon, > in addition to the existing "no struct device" implementation. Actually that doesn't do anything on DT platforms as of commit bdb0066df96e ("mfd: syscon: Decouple syscon interface from platform devices"). All the regmaps are, as I previously stated, not tied to any struct device. > > Here the provider device registers the (limited) regmap it wants to provide, > > tying the new regmap to itself. The consumer gets it via the dev_get_regmap() > > call. The provider has a main function and isn't exposing that part of its > > register map to the outside; only the random bits that were stuffed in are. > > > > > > With this scheme a device to could export just enough registers for the > > > > consumer to use, instead of the whole address range. > > > > > > > > We do this in the R40 clock controller as well, which has some bits that > > > > tweak the ethernet controllers RGMII delay... > > > > > > Not related. > > > > Related as in that is possibly what this code was based on, commit > > 49a06cae6e7c ("net: stmmac: dwmac-sun8i: Allow getting syscon regmap > > from external device"). > > > > > > ChenYu
WARNING: multiple messages have this Message-ID (diff)
From: Chen-Yu Tsai <wens@csie.org> To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Cc: Andre Przywara <andre.przywara@arm.com>, Vasily Khoruzhick <anarsoul@gmail.com>, Yangtao Li <tiny.windzz@gmail.com>, Jernej Skrabec <jernej.skrabec@gmail.com>, Samuel Holland <samuel@sholland.org>, "Rafael J . Wysocki" <rafael@kernel.org>, Daniel Lezcano <daniel.lezcano@linaro.org>, Zhang Rui <rui.zhang@intel.com>, Lukasz Luba <lukasz.luba@arm.com>, Rob Herring <robh+dt@kernel.org>, Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, Conor Dooley <conor+dt@kernel.org>, Martin Botka <martin.botka@somainline.org>, Bob McChesney <bob@electricworry.net>, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev Subject: Re: [PATCH v3 4/6] thermal: sun8i: add syscon register access code Date: Tue, 28 Nov 2023 17:09:21 +0800 [thread overview] Message-ID: <CAGb2v64Om8xqpgacbXV9Qf0tbV5qDcSOs7gW-uqSh2HD3Hhu3A@mail.gmail.com> (raw) In-Reply-To: <CAGb2v66L+sW-GQ4HvR-rXsG=JTi6vKt-9P-y1=vPqh0e5gKiOg@mail.gmail.com> On Tue, Nov 28, 2023 at 5:02 PM Chen-Yu Tsai <wens@csie.org> wrote: > > On Tue, Nov 28, 2023 at 4:59 PM Chen-Yu Tsai <wens@csie.org> wrote: > > > > On Tue, Nov 28, 2023 at 4:30 PM Krzysztof Kozlowski > > <krzysztof.kozlowski@linaro.org> wrote: > > > > > > On 28/11/2023 08:50, Chen-Yu Tsai wrote: > > > > On Tue, Nov 28, 2023 at 3:43 PM Krzysztof Kozlowski > > > > <krzysztof.kozlowski@linaro.org> wrote: > > > >> > > > >> On 28/11/2023 01:58, Andre Przywara wrote: > > > >>> > > > >>> +static struct regmap *sun8i_ths_get_syscon_regmap(struct device_node *node) > > > >>> +{ > > > >>> + struct device_node *syscon_node; > > > >>> + struct platform_device *syscon_pdev; > > > >>> + struct regmap *regmap = NULL; > > > >>> + > > > >>> + syscon_node = of_parse_phandle(node, "syscon", 0); > > > >> > > > >> Nope. For the 100th time, this cannot be generic. > > > >> > > > >>> + if (!syscon_node) > > > >>> + return ERR_PTR(-ENODEV); > > > >>> + > > > >>> + syscon_pdev = of_find_device_by_node(syscon_node); > > > >>> + if (!syscon_pdev) { > > > >>> + /* platform device might not be probed yet */ > > > >>> + regmap = ERR_PTR(-EPROBE_DEFER); > > > >>> + goto out_put_node; > > > >>> + } > > > >>> + > > > >>> + /* If no regmap is found then the other device driver is at fault */ > > > >>> + regmap = dev_get_regmap(&syscon_pdev->dev, NULL); > > > >>> + if (!regmap) > > > >>> + regmap = ERR_PTR(-EINVAL); > > > >> > > > >> Aren't you open-coding existing API to get regmap from syscon? > > > > > > > > Not really. This is to get a regmap exported by the device. Syscon's regmap > > > > is not tied to the device at all. > > > > > > I am talking about open-coding existing API. Look at syscon.h. > > > > The underlying implementation is different. > > > > syscon maintains its own mapping of device nodes to regmaps, and creates > > regmaps when none exist. The regmap is not tied to any struct device. > > syscon basically exists outside of the driver model and one has no control > > over what is exposed because it is meant for blocks that are a collection > > of random stuff. > > My bad. I failed to realize there is a platform device driver for syscon, > in addition to the existing "no struct device" implementation. Actually that doesn't do anything on DT platforms as of commit bdb0066df96e ("mfd: syscon: Decouple syscon interface from platform devices"). All the regmaps are, as I previously stated, not tied to any struct device. > > Here the provider device registers the (limited) regmap it wants to provide, > > tying the new regmap to itself. The consumer gets it via the dev_get_regmap() > > call. The provider has a main function and isn't exposing that part of its > > register map to the outside; only the random bits that were stuffed in are. > > > > > > With this scheme a device to could export just enough registers for the > > > > consumer to use, instead of the whole address range. > > > > > > > > We do this in the R40 clock controller as well, which has some bits that > > > > tweak the ethernet controllers RGMII delay... > > > > > > Not related. > > > > Related as in that is possibly what this code was based on, commit > > 49a06cae6e7c ("net: stmmac: dwmac-sun8i: Allow getting syscon regmap > > from external device"). > > > > > > ChenYu _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2023-11-28 9:09 UTC|newest] Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-11-28 0:58 [PATCH v3 0/6] Add support for H616 Thermal system Andre Przywara 2023-11-28 0:58 ` Andre Przywara 2023-11-28 0:58 ` [PATCH v3 1/6] soc: sunxi: sram: export register 0 for THS on H616 Andre Przywara 2023-11-28 0:58 ` Andre Przywara 2023-11-28 0:58 ` [PATCH v3 2/6] dt-bindings: thermal: sun8i: Add H616 THS controller Andre Przywara 2023-11-28 0:58 ` Andre Przywara 2023-11-28 7:41 ` Krzysztof Kozlowski 2023-11-28 7:41 ` Krzysztof Kozlowski 2023-11-28 0:58 ` [PATCH v3 3/6] thermal: sun8i: explain unknown H6 register value Andre Przywara 2023-11-28 0:58 ` Andre Przywara 2023-11-28 0:58 ` [PATCH v3 4/6] thermal: sun8i: add syscon register access code Andre Przywara 2023-11-28 0:58 ` Andre Przywara 2023-11-28 7:43 ` Krzysztof Kozlowski 2023-11-28 7:43 ` Krzysztof Kozlowski 2023-11-28 7:50 ` Chen-Yu Tsai 2023-11-28 7:50 ` Chen-Yu Tsai 2023-11-28 8:29 ` Krzysztof Kozlowski 2023-11-28 8:29 ` Krzysztof Kozlowski 2023-11-28 8:59 ` Chen-Yu Tsai 2023-11-28 8:59 ` Chen-Yu Tsai 2023-11-28 9:02 ` Chen-Yu Tsai 2023-11-28 9:02 ` Chen-Yu Tsai 2023-11-28 9:09 ` Chen-Yu Tsai [this message] 2023-11-28 9:09 ` Chen-Yu Tsai 2023-11-28 9:13 ` Krzysztof Kozlowski 2023-11-28 9:13 ` Krzysztof Kozlowski 2023-11-28 14:11 ` Krzysztof Kozlowski 2023-11-28 14:11 ` Krzysztof Kozlowski 2023-11-28 14:33 ` Andre Przywara 2023-11-28 14:33 ` Andre Przywara 2023-11-28 14:48 ` Krzysztof Kozlowski 2023-11-28 14:48 ` Krzysztof Kozlowski 2023-11-28 16:10 ` Andre Przywara 2023-11-28 16:10 ` Andre Przywara 2023-11-28 16:39 ` Chen-Yu Tsai 2023-11-28 16:39 ` Chen-Yu Tsai 2023-11-28 16:50 ` Rob Herring 2023-11-28 16:50 ` Rob Herring 2023-11-29 17:03 ` Andre Przywara 2023-11-29 17:03 ` Andre Przywara 2023-11-29 17:09 ` Chen-Yu Tsai 2023-11-29 17:09 ` Chen-Yu Tsai 2023-11-28 0:58 ` [PATCH v3 5/6] thermal: sun8i: add support for H616 THS controller Andre Przywara 2023-11-28 0:58 ` Andre Przywara 2023-12-09 10:44 ` Maksim Kiselev 2023-12-09 10:44 ` Maksim Kiselev 2023-12-11 0:05 ` Andre Przywara 2023-12-11 0:05 ` Andre Przywara 2023-12-12 18:09 ` Maxim Kiselev 2023-12-12 18:09 ` Maxim Kiselev 2023-12-14 9:59 ` Andre Przywara 2023-12-14 9:59 ` Andre Przywara 2023-12-17 14:16 ` Maxim Kiselev 2023-12-17 14:16 ` Maxim Kiselev 2023-11-28 0:58 ` [PATCH v3 6/6] arm64: dts: allwinner: h616: Add thermal sensor and zones Andre Przywara 2023-11-28 0:58 ` Andre Przywara
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=CAGb2v64Om8xqpgacbXV9Qf0tbV5qDcSOs7gW-uqSh2HD3Hhu3A@mail.gmail.com \ --to=wens@csie.org \ --cc=anarsoul@gmail.com \ --cc=andre.przywara@arm.com \ --cc=bob@electricworry.net \ --cc=conor+dt@kernel.org \ --cc=daniel.lezcano@linaro.org \ --cc=devicetree@vger.kernel.org \ --cc=jernej.skrabec@gmail.com \ --cc=krzysztof.kozlowski+dt@linaro.org \ --cc=krzysztof.kozlowski@linaro.org \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-pm@vger.kernel.org \ --cc=linux-sunxi@lists.linux.dev \ --cc=lukasz.luba@arm.com \ --cc=martin.botka@somainline.org \ --cc=rafael@kernel.org \ --cc=robh+dt@kernel.org \ --cc=rui.zhang@intel.com \ --cc=samuel@sholland.org \ --cc=tiny.windzz@gmail.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.