From nobody Sun Nov 24 11:32:05 2024 Received: from mail-pl1-f176.google.com (mail-pl1-f176.google.com [209.85.214.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D2BAA1DD0FE for ; Wed, 6 Nov 2024 09:34:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.176 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730885662; cv=none; b=f61oI6ljv7oXNIIvXrXdY3SvhtZxM+4ys0i+DEnkEliDUB+70E99vSpKcyWsOVVYA/luv1PBB4e5kUPFrnPvKOvvvcxFVEF0oDDizGsJGIek+q8LumHsLkY4u91/6gT15MQgnTmA+1KoJsJIYByngExlSIB9k+ARht8qW78qsE0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730885662; c=relaxed/simple; bh=i7tB2LF9Va8QhzXWbLe5vhJbCYE/IUIrHJ7AVTFvlAo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZQDLDvl9iF4KvTI/OzJhw2cn5/VrXrj3QGZvWmHUGbkPb9WtzodxPZF3d775Qi6ryu7cp2ddTUbdy6xrGYZ/ow+huyQ7U8oywTqwsbkPEaoJQOLK261CpCrlza34levLlRwlR0G+R1X9wz53ZVSC57lbv98izWhK1U02oUe/kdM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=IF97lHj3; arc=none smtp.client-ip=209.85.214.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="IF97lHj3" Received: by mail-pl1-f176.google.com with SMTP id d9443c01a7336-20cdbe608b3so64570035ad.1 for ; Wed, 06 Nov 2024 01:34:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1730885659; x=1731490459; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=1ZQCxJwfexAjnJDSPigCQy78WL7sgzBAoIFw8zKeVQo=; b=IF97lHj3ZrAytBzYiFgmervHfRoF6LL4wLXLEWjRH9CTAQOt00l8+Fbv40A7Fo7hG7 /rCni39D43I0wO7eu7KiB0LeCV08G/TQQm0JC6aNUq+Rxjyc/CyfqIeQ+itzMePZCx1e /+SIFw2cwKeZk/HgKV2o/h7nRntLcwHNWnZcM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730885659; x=1731490459; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=1ZQCxJwfexAjnJDSPigCQy78WL7sgzBAoIFw8zKeVQo=; b=kD+4HeQI0KfDWtoiSlbcqWDHtUsF4E5M/Mrr9yV/XyA3n75GpuqsV8n+jRk9t5nRYq 3N+L01OCDvn1/p5MoJVN0Sl2nUh2uwN6nsAtrWSkf2CnkTqJJHC7eCpF87JdU1lNShJE m32FoXQAOSdTvss7rb9ymQQvFxuc6KkZwsAtErUseUf+H2xjpnLaZwT9VU8LJOnRWwqV n4uyWMRlcvaHsc8I3kKicm95znIUZs6Qlaw00h6GAas7RPWfN61/gr8SX2jWW6WQdZCE 07Md1SSFD+Q8xLfUfDsyov2ilhyiYAweVML4n2WV38M0oVGhO0qC2gdnZA0aXrHYG3Tj nyQg== X-Forwarded-Encrypted: i=1; AJvYcCUV9ty6mQR591obM/zR0n/OMOHQJwr1vs5QbtAVZU93o+uIGJ1kTa1WlZSOoRmlmWH/r5F4hVdwO0xkLfU=@vger.kernel.org X-Gm-Message-State: AOJu0Yyqv09Vu+Rqa8yOHawFqduNEg4BEDCjXnobv5Mc/y09Filc4Tai Rncfyd19xMB1YYlGArlC4H+L/TKeDB6ExTLJNCow90kVPw4Yjp4EId91AJ16zA== X-Google-Smtp-Source: AGHT+IEClACp1l7bIsTYEVdHiEtgpnPWujmbCJ8LMiaczL1P3ezxA2tzFOv4EeTcreC147LMJ38KLA== X-Received: by 2002:a17:902:f684:b0:20c:cd14:a7f3 with SMTP id d9443c01a7336-210f7523562mr382589885ad.22.1730885659184; Wed, 06 Nov 2024 01:34:19 -0800 (PST) Received: from wenstp920.tpe.corp.google.com ([2401:fa00:1:10:93fe:1d68:b50:3213]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-211057062b8sm91478665ad.63.2024.11.06.01.34.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 Nov 2024 01:34:18 -0800 (PST) From: Chen-Yu Tsai To: Matthias Brugger , AngeloGioacchino Del Regno , Wolfram Sang Cc: Chen-Yu Tsai , Rob Herring , Saravana Kannan , Benson Leung , Tzung-Bi Shih , chrome-platform@lists.linux.dev, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, Douglas Anderson , Johan Hovold , Jiri Kosina , Andy Shevchenko , linux-i2c@vger.kernel.org, Andrey Skvortsov Subject: [PATCH v11 4/7] i2c: of-prober: Add simple helpers for regulator support Date: Wed, 6 Nov 2024 17:33:31 +0800 Message-ID: <20241106093335.1582205-5-wenst@chromium.org> X-Mailer: git-send-email 2.47.0.199.ga7371fff76-goog In-Reply-To: <20241106093335.1582205-1-wenst@chromium.org> References: <20241106093335.1582205-1-wenst@chromium.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add helpers to do regulator management for the I2C OF component prober. Components that the prober intends to probe likely require their regulator supplies be enabled, and GPIOs be toggled to enable them or bring them out of reset before they will respond to probe attempts. GPIOs will be handled in the next patch. The assumption is that the same class of components to be probed are always connected in the same fashion with the same regulator supply and GPIO. The names may vary due to binding differences, but the physical layout does not change. This set of helpers supports at most one regulator supply. The user must specify the node from which the supply is retrieved. The supply name and the amount of time to wait after the supply is enabled are also given by the user. Signed-off-by: Chen-Yu Tsai Reviewed-by: Douglas Anderson Reviewed-by: Andy Shevchenko Reviewed-by: AngeloGioacchino Del Regno --- Changes since v9: - Picked up Andy's reviewed-by Changes since v8: - Picked up Doug's reviewed-by Changes since v7: - Reworded comment in i2c_of_probe_simple_get_supply() as suggested (Andy) - Dropped mention of time unit in struct i2c_of_probe_simple_opts kernel doc (Andy) - Added mention of common GPIO line usages ("enable" or "reset") in I2C OF component prober kernel doc (Doug) - Added check for non-zero delay before msleep() (Doug) - Combined callback helpers (.get_resources with .enable; .cleanup with .free_resources_late) Changes since v6: - Moved change of of_get_next_child_scoped() to of_get_next_child_with_prefix() to previous patch - Restructured into helpers for the I2C OF component prober - Reduced to only handle one regulator - Commit message updated Changes since v5: - Split of_regulator_bulk_get_all() return value check and explain "ret =3D=3D 0" case - Switched to of_get_next_child_with_prefix_scoped() where applicable - Used krealloc_array() instead of directly calculating size - copy whole regulator array in one memcpy() call - Drop "0" from struct zeroing initializer - Split out regulator helper from i2c_of_probe_enable_res() to keep code cleaner when combined with the next patch - Added options for customizing power sequencing delay - Rename i2c_of_probe_get_regulator() to i2c_of_probe_get_regulators() - Add i2c_of_probe_free_regulator() helper Changes since v4: - Split out GPIO handling to separate patch - Rewrote using of_regulator_bulk_get_all() - Replaced "regulators" with "regulator supplies" in debug messages Changes since v3: - New patch --- drivers/i2c/i2c-core-of-prober.c | 138 ++++++++++++++++++++++++++++++- include/linux/i2c-of-prober.h | 44 ++++++++++ 2 files changed, 181 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/i2c-core-of-prober.c b/drivers/i2c/i2c-core-of-pro= ber.c index 21f7a4769293..76df75c51cae 100644 --- a/drivers/i2c/i2c-core-of-prober.c +++ b/drivers/i2c/i2c-core-of-prober.c @@ -6,6 +6,7 @@ */ =20 #include +#include #include #include #include @@ -13,6 +14,7 @@ #include #include #include +#include #include #include =20 @@ -29,7 +31,6 @@ * address responds. * * TODO: - * - Support handling common regulators. * - Support handling common GPIOs. * - Support I2C muxes */ @@ -181,3 +182,138 @@ int i2c_of_probe_component(struct device *dev, const = struct i2c_of_probe_cfg *cf return ret; } EXPORT_SYMBOL_NS_GPL(i2c_of_probe_component, I2C_OF_PROBER); + +static int i2c_of_probe_simple_get_supply(struct device *dev, struct devic= e_node *node, + struct i2c_of_probe_simple_ctx *ctx) +{ + const char *supply_name; + struct regulator *supply; + + /* + * It's entirely possible for the component's device node to not have the + * regulator supplies. While it does not make sense from a hardware persp= ective, + * the supplies could be always on or otherwise not modeled in the device= tree, + * but the device would still work. + */ + supply_name =3D ctx->opts->supply_name; + if (!supply_name) + return 0; + + supply =3D of_regulator_get_optional(dev, node, supply_name); + if (IS_ERR(supply)) { + return dev_err_probe(dev, PTR_ERR(supply), + "Failed to get regulator supply \"%s\" from %pOF\n", + supply_name, node); + } + + ctx->supply =3D supply; + + return 0; +} + +static void i2c_of_probe_simple_put_supply(struct i2c_of_probe_simple_ctx = *ctx) +{ + regulator_put(ctx->supply); + ctx->supply =3D NULL; +} + +static int i2c_of_probe_simple_enable_regulator(struct device *dev, struct= i2c_of_probe_simple_ctx *ctx) +{ + int ret; + + if (!ctx->supply) + return 0; + + dev_dbg(dev, "Enabling regulator supply \"%s\"\n", ctx->opts->supply_name= ); + + ret =3D regulator_enable(ctx->supply); + if (ret) + return ret; + + if (ctx->opts->post_power_on_delay_ms) + msleep(ctx->opts->post_power_on_delay_ms); + + return 0; +} + +static void i2c_of_probe_simple_disable_regulator(struct device *dev, stru= ct i2c_of_probe_simple_ctx *ctx) +{ + if (!ctx->supply) + return; + + dev_dbg(dev, "Disabling regulator supply \"%s\"\n", ctx->opts->supply_nam= e); + + regulator_disable(ctx->supply); +} + +/** + * i2c_of_probe_simple_enable - Simple helper for I2C OF prober to get and= enable resources + * @dev: Pointer to the &struct device of the caller, only used for dev_pr= intk() messages + * @bus_node: Pointer to the &struct device_node of the I2C adapter. + * @data: Pointer to &struct i2c_of_probe_simple_ctx helper context. + * + * If &i2c_of_probe_simple_opts->supply_name is given, request the named r= egulator supply. + * If a regulator supply was found, enable that regulator. + * + * Return: %0 on success or no-op, or a negative error number on failure. + */ +int i2c_of_probe_simple_enable(struct device *dev, struct device_node *bus= _node, void *data) +{ + struct i2c_of_probe_simple_ctx *ctx =3D data; + struct device_node *node; + const char *compat; + int ret; + + dev_dbg(dev, "Requesting resources for components under I2C bus %pOF\n", = bus_node); + + if (!ctx || !ctx->opts) + return -EINVAL; + + compat =3D ctx->opts->res_node_compatible; + if (!compat) + return -EINVAL; + + node =3D of_get_compatible_child(bus_node, compat); + if (!node) + return dev_err_probe(dev, -ENODEV, "No device compatible with \"%s\" fou= nd\n", + compat); + + ret =3D i2c_of_probe_simple_get_supply(dev, node, ctx); + if (ret) + goto out_put_node; + + ret =3D i2c_of_probe_simple_enable_regulator(dev, ctx); + if (ret) + goto out_put_supply; + + return 0; + +out_put_supply: + i2c_of_probe_simple_put_supply(ctx); +out_put_node: + of_node_put(node); + return ret; +} +EXPORT_SYMBOL_NS_GPL(i2c_of_probe_simple_enable, I2C_OF_PROBER); + +/** + * i2c_of_probe_simple_cleanup - Clean up and release resources for I2C OF= prober simple helpers + * @dev: Pointer to the &struct device of the caller, only used for dev_pr= intk() messages + * @data: Pointer to &struct i2c_of_probe_simple_ctx helper context. + * + * * If a regulator supply was found, disable that regulator and release i= t. + */ +void i2c_of_probe_simple_cleanup(struct device *dev, void *data) +{ + struct i2c_of_probe_simple_ctx *ctx =3D data; + + i2c_of_probe_simple_disable_regulator(dev, ctx); + i2c_of_probe_simple_put_supply(ctx); +} +EXPORT_SYMBOL_NS_GPL(i2c_of_probe_simple_cleanup, I2C_OF_PROBER); + +struct i2c_of_probe_ops i2c_of_probe_simple_ops =3D { + .enable =3D i2c_of_probe_simple_enable, + .cleanup =3D i2c_of_probe_simple_cleanup, +}; +EXPORT_SYMBOL_NS_GPL(i2c_of_probe_simple_ops, I2C_OF_PROBER); diff --git a/include/linux/i2c-of-prober.h b/include/linux/i2c-of-prober.h index e7e052ac9e48..df95aa6ad90e 100644 --- a/include/linux/i2c-of-prober.h +++ b/include/linux/i2c-of-prober.h @@ -70,6 +70,50 @@ struct i2c_of_probe_cfg { =20 int i2c_of_probe_component(struct device *dev, const struct i2c_of_probe_c= fg *cfg, void *ctx); =20 +/** + * DOC: I2C OF component prober simple helpers + * + * Components such as trackpads are commonly connected to a devices basebo= ard + * with a 6-pin ribbon cable. That gives at most one voltage supply and one + * GPIO (commonly a "enable" or "reset" line) besides the I2C bus, interru= pt + * pin, and common ground. Touchscreens, while integrated into the display + * panel's connection, typically have the same set of connections. + * + * A simple set of helpers are provided here for use with the I2C OF compo= nent + * prober. This implementation targets such components, allowing for at mo= st + * one regulator supply. + * + * The following helpers are provided: + * * i2c_of_probe_simple_enable() + * * i2c_of_probe_simple_cleanup() + */ + +/** + * struct i2c_of_probe_simple_opts - Options for simple I2C component prob= er callbacks + * @res_node_compatible: Compatible string of device node to retrieve reso= urces from. + * @supply_name: Name of regulator supply. + * @post_power_on_delay_ms: Delay after regulators are powered on. Passed = to msleep(). + */ +struct i2c_of_probe_simple_opts { + const char *res_node_compatible; + const char *supply_name; + unsigned int post_power_on_delay_ms; +}; + +struct regulator; + +struct i2c_of_probe_simple_ctx { + /* public: provided by user before helpers are used. */ + const struct i2c_of_probe_simple_opts *opts; + /* private: internal fields for helpers. */ + struct regulator *supply; +}; + +int i2c_of_probe_simple_enable(struct device *dev, struct device_node *bus= _node, void *data); +void i2c_of_probe_simple_cleanup(struct device *dev, void *data); + +extern struct i2c_of_probe_ops i2c_of_probe_simple_ops; + #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ =20 #endif /* _LINUX_I2C_OF_PROBER_H */ --=20 2.47.0.199.ga7371fff76-goog