From patchwork Tue Feb 17 18:52:02 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Hesselbarth X-Patchwork-Id: 440685 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3CC7D1401EF for ; Wed, 18 Feb 2015 05:54:54 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751532AbbBQSyh (ORCPT ); Tue, 17 Feb 2015 13:54:37 -0500 Received: from mail-we0-f170.google.com ([74.125.82.170]:44563 "EHLO mail-we0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751895AbbBQSwg (ORCPT ); Tue, 17 Feb 2015 13:52:36 -0500 Received: by wesk11 with SMTP id k11so256012wes.11; Tue, 17 Feb 2015 10:52:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=Jaf+pFEkpHvft0Yf72JNS5VQ5OaaFRcE7qCSSPhGvR4=; b=tXSx7jG9Er98fwNj1pHU7xg3zoDdiZTJ2VEeCvMphNaaYGG7xLgGe3dqh+HIgsNk4H 4VBV/nCrQDjyo3SUISFORQSFlcX3vv8RLwfULlJEb8DhFqzUdKGEMLEZL6D4BqDGod0G tgEj66odkRMTVK23HUXWQ483BDLCKN7HmO8PQvxd9B/Rucs35U1KeU0zPTmjOi74iXmf caVw7ICLfiwn8tNXSG8qCsI+aMAGAexfP87VsOarSp1Gixrdy8hKtwr+9EmjbCtRsh2h laNUVyW+qwl7B0TYhOOa/P9yjgoqMzLme5CiT8GNivNfU6MuZ+XSzXY4lm8fXvYWC7LL 9Wyw== X-Received: by 10.194.237.34 with SMTP id uz2mr63193899wjc.157.1424199154767; Tue, 17 Feb 2015 10:52:34 -0800 (PST) Received: from topkick.lan (f051045211.adsl.alicedsl.de. [78.51.45.211]) by mx.google.com with ESMTPSA id do1sm21445996wib.3.2015.02.17.10.52.33 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 17 Feb 2015 10:52:33 -0800 (PST) From: Sebastian Hesselbarth To: Sebastian Hesselbarth Cc: Jason Cooper , Andrew Lunn , Gregory Clement , Gabriel Dobato , Wolfram Sang , Stephen Warren , linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/8] i2c: mux-pinctrl: Rework to honor disabled child nodes Date: Tue, 17 Feb 2015 19:52:02 +0100 Message-Id: <1424199129-22099-2-git-send-email-sebastian.hesselbarth@gmail.com> In-Reply-To: <1424199129-22099-1-git-send-email-sebastian.hesselbarth@gmail.com> References: <1424199129-22099-1-git-send-email-sebastian.hesselbarth@gmail.com> Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org I2C mux pinctrl driver currently determines the number of sub-busses by counting available pinctrl-names. Unfortunately, this requires each incarnation of the devicetree node with different available sub-busses to be rewritten. This patch reworks i2c-mux-pinctrl driver to count the number of available sub-nodes instead. The rework should be compatible to the old way of probing for sub-busses and additionally allows to disable unused sub-busses with standard DT property status = "disabled". This also amends the corresponding devicetree binding documentation to reflect the new functionality to disable unused sub-nodes. While at it, also fix two references to binding documentation files that miss an "i2c-" prefix. Signed-off-by: Sebastian Hesselbarth Tested-by: Stephen Warren --- Cc: Jason Cooper Cc: Andrew Lunn Cc: Gregory Clement Cc: Gabriel Dobato Cc: Wolfram Sang Cc: Stephen Warren Cc: linux-i2c@vger.kernel.org Cc: devicetree@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org --- .../devicetree/bindings/i2c/i2c-mux-pinctrl.txt | 28 ++++----- drivers/i2c/muxes/i2c-mux-pinctrl.c | 70 ++++++++++++++-------- 2 files changed, 59 insertions(+), 39 deletions(-) diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.txt index ae8af1694e95..24b9fdef8850 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.txt @@ -28,27 +28,24 @@ Also required are: * Standard pinctrl properties that specify the pin mux state for each child bus. See ../pinctrl/pinctrl-bindings.txt. -* Standard I2C mux properties. See mux.txt in this directory. +* Standard I2C mux properties. See i2c-mux.txt in this directory. -* I2C child bus nodes. See mux.txt in this directory. +* I2C child bus nodes. See i2c-mux.txt in this directory. -For each named state defined in the pinctrl-names property, an I2C child bus -will be created. I2C child bus numbers are assigned based on the index into -the pinctrl-names property. +For each child node that is not disabled by a status != "okay", an I2C +child bus will be created. I2C child bus numbers are assigned based on the +order of child nodes. -The only exception is that no bus will be created for a state named "idle". If -such a state is defined, it must be the last entry in pinctrl-names. For -example: - - pinctrl-names = "ddc", "pta", "idle" -> ddc = bus 0, pta = bus 1 - pinctrl-names = "ddc", "idle", "pta" -> Invalid ("idle" not last) - pinctrl-names = "idle", "ddc", "pta" -> Invalid ("idle" not last) +There must be a corresponding pinctrl-names entry for each enabled child +node at the position of the child node's "reg" property. Whenever an access is made to a device on a child bus, the relevant pinctrl state will be programmed into hardware. -If an idle state is defined, whenever an access is not being made to a device -on a child bus, the idle pinctrl state will be programmed into hardware. +Also, there can be an idle pinctrl state defined at the end of possible +pinctrl states. If an idle state is defined, whenever an access is not being +made to a device on a child bus, the idle pinctrl state will be programmed +into hardware. If an idle state is not defined, the most recently used pinctrl state will be left programmed into hardware whenever no access is being made of a device on @@ -68,6 +65,7 @@ Example: pinctrl-1 = <&state_i2cmux_pta>; pinctrl-2 = <&state_i2cmux_idle>; + /* Enabled child bus 0 */ i2c@0 { reg = <0>; #address-cells = <1>; @@ -79,10 +77,12 @@ Example: }; }; + /* Disabled child bus 1 */ i2c@1 { reg = <1>; #address-cells = <1>; #size-cells = <0>; + status = "disabled"; eeprom { compatible = "eeprom"; diff --git a/drivers/i2c/muxes/i2c-mux-pinctrl.c b/drivers/i2c/muxes/i2c-mux-pinctrl.c index b48378c4b40d..033dacfabfdf 100644 --- a/drivers/i2c/muxes/i2c-mux-pinctrl.c +++ b/drivers/i2c/muxes/i2c-mux-pinctrl.c @@ -56,9 +56,12 @@ static int i2c_mux_pinctrl_parse_dt(struct i2c_mux_pinctrl *mux, struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; - int num_names, i, ret; + struct device_node *child; + struct property *prop; + int num_names, num_children, ret; struct device_node *adapter_np; struct i2c_adapter *adapter; + const char *state; if (!np) return 0; @@ -77,32 +80,16 @@ static int i2c_mux_pinctrl_parse_dt(struct i2c_mux_pinctrl *mux, return num_names; } - mux->pdata->pinctrl_states = devm_kzalloc(&pdev->dev, - sizeof(*mux->pdata->pinctrl_states) * num_names, - GFP_KERNEL); - if (!mux->pdata->pinctrl_states) { - dev_err(mux->dev, "Cannot allocate pinctrl_states\n"); - return -ENOMEM; + num_children = of_get_available_child_count(np); + if (num_children < 0) { + dev_err(mux->dev, "Unable to count available children: %d\n", + num_children); + return num_children; } - for (i = 0; i < num_names; i++) { - ret = of_property_read_string_index(np, "pinctrl-names", i, - &mux->pdata->pinctrl_states[mux->pdata->bus_count]); - if (ret < 0) { - dev_err(mux->dev, "Cannot parse pinctrl-names: %d\n", - ret); - return ret; - } - if (!strcmp(mux->pdata->pinctrl_states[mux->pdata->bus_count], - "idle")) { - if (i != num_names - 1) { - dev_err(mux->dev, "idle state must be last\n"); - return -EINVAL; - } - mux->pdata->pinctrl_state_idle = "idle"; - } else { - mux->pdata->bus_count++; - } + if (num_names < num_children) { + dev_err(mux->dev, "Found less pinctrl states than children\n"); + return -EINVAL; } adapter_np = of_parse_phandle(np, "i2c-parent", 0); @@ -118,6 +105,39 @@ static int i2c_mux_pinctrl_parse_dt(struct i2c_mux_pinctrl *mux, mux->pdata->parent_bus_num = i2c_adapter_id(adapter); put_device(&adapter->dev); + mux->pdata->pinctrl_states = devm_kzalloc(&pdev->dev, + sizeof(*mux->pdata->pinctrl_states) * num_children, + GFP_KERNEL); + if (!mux->pdata->pinctrl_states) { + dev_err(mux->dev, "Cannot allocate pinctrl_states\n"); + return -ENOMEM; + } + + of_property_for_each_string(np, "pinctrl-names", prop, state) + if (!strcmp(state, "idle")) + mux->pdata->pinctrl_state_idle = "idle"; + + for_each_available_child_of_node(np, child) { + u32 reg; + + ret = of_property_read_u32(child, "reg", ®); + if (ret < 0) { + dev_err(mux->dev, "Missing reg property for child node: %d\n", + ret); + return ret; + } + + ret = of_property_read_string_index(np, + "pinctrl-names", reg, &state); + if (ret < 0) { + dev_err(mux->dev, "Cannot parse pinctrl-names for mux %d: %d\n", + reg, ret); + return ret; + } + + mux->pdata->pinctrl_states[mux->pdata->bus_count++] = state; + } + return 0; } #else