From patchwork Wed Mar 18 15:00:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 11445423 X-Patchwork-Delegate: geert@linux-m68k.org Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9D5AD92A for ; Wed, 18 Mar 2020 15:01:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 85DB820757 for ; Wed, 18 Mar 2020 15:01:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727095AbgCRPBL (ORCPT ); Wed, 18 Mar 2020 11:01:11 -0400 Received: from sauhun.de ([88.99.104.3]:48444 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726936AbgCRPBI (ORCPT ); Wed, 18 Mar 2020 11:01:08 -0400 Received: from localhost (p54B333FA.dip0.t-ipconnect.de [84.179.51.250]) by pokefinder.org (Postfix) with ESMTPSA id B29E42C2E79; Wed, 18 Mar 2020 16:01:05 +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, Wolfram Sang , Geert Uytterhoeven , Rob Herring Subject: [RFC PATCH v2 2/6] i2c: allow DT nodes without 'compatible' Date: Wed, 18 Mar 2020 16:00:55 +0100 Message-Id: <20200318150059.21714-3-wsa+renesas@sang-engineering.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200318150059.21714-1-wsa+renesas@sang-engineering.com> References: <20200318150059.21714-1-wsa+renesas@sang-engineering.com> MIME-Version: 1.0 Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@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 Reviewed-by: Luca Ceresoli Reviewed-by: Kieran Bingham --- Documentation/devicetree/bindings/i2c/i2c-ocores.txt | 2 -- 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(+), 8 deletions(-) diff --git a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt index 6b25a80ae8d3..fc8ea27934b3 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>; }; }; @@ -68,7 +67,6 @@ or 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 3d7b8a00a7d9..84464e439df5 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