From patchwork Thu Feb 20 17:23:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 1241583 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=sang-engineering.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 48NhMB0YpBz9sPK for ; Fri, 21 Feb 2020 04:25:58 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728869AbgBTRZz (ORCPT ); Thu, 20 Feb 2020 12:25:55 -0500 Received: from sauhun.de ([88.99.104.3]:35088 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727709AbgBTRZz (ORCPT ); Thu, 20 Feb 2020 12:25:55 -0500 Received: from localhost (p5486CC48.dip0.t-ipconnect.de [84.134.204.72]) by pokefinder.org (Postfix) with ESMTPSA id 1ED662C1EBE; Thu, 20 Feb 2020 18:25:52 +0100 (CET) From: Wolfram Sang To: linux-i2c@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, linux-i3c@lists.infradead.org, Kieran Bingham , =?utf-8?q?Niklas_S=C3=B6derlund?= , Luca Ceresoli , Jacopo Mondi , Laurent Pinchart , Vladimir Zapolskiy , linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Wolfram Sang Subject: [RFC PATCH 3/7] i2c: allow DT nodes without 'compatible' Date: Thu, 20 Feb 2020 18:23:59 +0100 Message-Id: <20200220172403.26062-4-wsa+renesas@sang-engineering.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200220172403.26062-1-wsa+renesas@sang-engineering.com> References: <20200220172403.26062-1-wsa+renesas@sang-engineering.com> MIME-Version: 1.0 Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Sometimes, we have unknown devices in a system and still want to block their address. For that, we allow DT nodes with only a 'reg' property. These devices will be bound to the "dummy" driver but with the name "reserved". That way, we can distinguish them and even hand them over to the "dummy" driver later when they are really requested using i2c_new_ancillary_device(). Signed-off-by: Wolfram Sang Reviewed-by: Geert Uytterhoeven Acked-by: Rob Herring --- Documentation/devicetree/bindings/i2c/i2c-ocores.txt | 1 - Documentation/devicetree/bindings/i2c/i2c.txt | 4 +++- drivers/i2c/i2c-core-base.c | 1 + drivers/i2c/i2c-core-of.c | 8 +++----- drivers/i2c/i2c-core.h | 1 + 5 files changed, 8 insertions(+), 7 deletions(-) diff --git a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt index 6b25a80ae8d3..2762effdd270 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt @@ -50,7 +50,6 @@ Examples: reg-io-width = <1>; /* 8 bit read/write */ dummy@60 { - compatible = "dummy"; reg = <0x60>; }; }; diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt index 9a53df4243c6..989b315e09dc 100644 --- a/Documentation/devicetree/bindings/i2c/i2c.txt +++ b/Documentation/devicetree/bindings/i2c/i2c.txt @@ -21,7 +21,9 @@ flags can be attached to the address. I2C_TEN_BIT_ADDRESS is used to mark a 10 bit address. It is needed to avoid the ambiguity between e.g. a 7 bit address of 0x50 and a 10 bit address of 0x050 which, in theory, can be on the same bus. Another flag is I2C_OWN_SLAVE_ADDRESS to mark addresses on which we listen to -be devices ourselves. +be devices ourselves. The 'reg' property of a child is required. The +'compatible' property is not. Empty 'compatible' child entries can be used to +describe unknown devices or addresses which shall be blocked for other reasons. Optional properties ------------------- diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 8df2fa10c48a..4000a4384306 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -854,6 +854,7 @@ EXPORT_SYMBOL_GPL(i2c_unregister_device); static const struct i2c_device_id dummy_id[] = { { I2C_DUMMY_DRV_NAME, 0 }, + { I2C_RESERVED_DRV_NAME, 0 }, { }, }; diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c index 6787c1f71483..d8d111ad6c85 100644 --- a/drivers/i2c/i2c-core-of.c +++ b/drivers/i2c/i2c-core-of.c @@ -27,17 +27,15 @@ int of_i2c_get_board_info(struct device *dev, struct device_node *node, memset(info, 0, sizeof(*info)); - if (of_modalias_node(node, info->type, sizeof(info->type)) < 0) { - dev_err(dev, "of_i2c: modalias failure on %pOF\n", node); - return -EINVAL; - } - ret = of_property_read_u32(node, "reg", &addr); if (ret) { dev_err(dev, "of_i2c: invalid reg on %pOF\n", node); return ret; } + if (of_modalias_node(node, info->type, sizeof(info->type)) < 0) + strlcpy(info->type, I2C_RESERVED_DRV_NAME, sizeof(I2C_RESERVED_DRV_NAME)); + if (addr & I2C_TEN_BIT_ADDRESS) { addr &= ~I2C_TEN_BIT_ADDRESS; info->flags |= I2C_CLIENT_TEN; diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h index fb89fabf84d3..77b3a925ed95 100644 --- a/drivers/i2c/i2c-core.h +++ b/drivers/i2c/i2c-core.h @@ -23,6 +23,7 @@ int i2c_dev_irq_from_resources(const struct resource *resources, unsigned int num_resources); #define I2C_DUMMY_DRV_NAME "dummy" +#define I2C_RESERVED_DRV_NAME "reserved" /* * We only allow atomic transfers for very late communication, e.g. to send