From patchwork Fri Mar 23 16:11:17 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anup Patel X-Patchwork-Id: 10305077 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4D948600CC for ; Fri, 23 Mar 2018 16:11:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3DCCF28FFC for ; Fri, 23 Mar 2018 16:11:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3183E28FFF; Fri, 23 Mar 2018 16:11:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8EB2D28FFC for ; Fri, 23 Mar 2018 16:11:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751907AbeCWQLp (ORCPT ); Fri, 23 Mar 2018 12:11:45 -0400 Received: from mail-pl0-f68.google.com ([209.85.160.68]:37576 "EHLO mail-pl0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751682AbeCWQLo (ORCPT ); Fri, 23 Mar 2018 12:11:44 -0400 Received: by mail-pl0-f68.google.com with SMTP id w12-v6so7704008plp.4 for ; Fri, 23 Mar 2018 09:11:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=brainfault-org.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id; bh=SDDKIKJvOaO95L1DwrD7AIi0Ge2zJ6cwDgr+kkHakxg=; b=x0sVjdvj/ZSVXxxBZSCQeAI6OGozC6N+mcyFBsbKVF9H4E6yUAZM8HtBcHDRZ9WzaQ U4uuctFji94hmwWUKtk3B+KqMmzibg+WYKh+ZB3MrEzxpIEwkmef5Ck3/gMT7pMnMRxG 7Pf1jU45OrBbgyxmqTM4Ty9QXjNeLYtIV2PMCHbo4Fa4UmYMspTBWw0eawiSckMAwVfl bjIkTchmPOcOLMpR0FA5z6Tq7i4ZKVvFFxNVyzR+guXDgoVgFWbNyal0YLrMWDvI3rMb WyXf4Wah7TpF9iDZd7shW+1mjKYEUhOElEArxXkWj7CV+nCXd6ESQ8+fCztdyDVIomEr 0Hxw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=SDDKIKJvOaO95L1DwrD7AIi0Ge2zJ6cwDgr+kkHakxg=; b=O9bdgMRxRfU6i4PEIR6yJWG71X6CENCeCxYai36bTuEZvFKqR45liRDFp+Mdf/FwZf D6JnoAopIvIUCP9WjZqhMeGUYtFzuuA1ZABDYHCHZt6LzunKSHtDk4zb9cGv9QCCyM2E c40/dVJcIItjNrrpZOM7mWLJzKKtmz6Lyu1hIJTGR30ITYTXjmz2dFF0OjEbhRC1+Cnt wae4M4orrizt+rzBwiwHz3K/5Gu5DSHVVG5iJh2WMH+5poL4DxaYPjhVy+5TxQMMJNgR edJWdqM43JnQCy/d94REZpgtfuMnck/Q7Vmk/4q0w4MLExxTBX2/UUpkLTeIE1hCy/o0 DQQQ== X-Gm-Message-State: AElRT7HW5AFuToLxjtHtOEXaDYpIChJniCzYg+uDOY3zDDC61jEKH+me QN6WHzRYIDNwtsGtlxnj/t4GLQ== X-Google-Smtp-Source: AG47ELtJs2Hl5lDxxsofHihEirb13Vd+pSu0EpEBcc+WiZWT3EL9EHDW0TyFa6GJyJ9JvwdYZG3L5Q== X-Received: by 2002:a17:902:9a8b:: with SMTP id w11-v6mr23599777plp.136.1521821503293; Fri, 23 Mar 2018 09:11:43 -0700 (PDT) Received: from localhost.localdomain ([106.51.27.252]) by smtp.googlemail.com with ESMTPSA id m185sm10715375pfc.132.2018.03.23.09.11.40 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 23 Mar 2018 09:11:42 -0700 (PDT) From: Anup Patel To: Ohad Ben-Cohen , Bjorn Andersson Cc: linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, Anup Patel Subject: [PATCH v2] rpmsg: Add driver_override device attribute for rpmsg_device Date: Fri, 23 Mar 2018 21:41:17 +0530 Message-Id: <1521821477-31378-1-git-send-email-anup@brainfault.org> X-Mailer: git-send-email 2.7.4 Sender: linux-remoteproc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-remoteproc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds "driver_override" device attribute for rpmsg_device which will allow users to explicitly specify the rpmsg_driver to be used via sysfs entry. The "driver_override" device attribute implemented here is very similar to "driver_override" implemented for platform, pci, and amba bus types. One important use-case of "driver_override" device attribute is to force use of rpmsg_chrdev driver for certain rpmsg_device instances. Signed-off-by: Anup Patel Changes since v1: - Removed un-related changes from patch - Renamed "path" to "member" in rpmsg_string_attr() macro - Used strcspn() instead of strchr() in rpmsg_string_attr() macro --- Documentation/ABI/testing/sysfs-bus-rpmsg | 20 ++++++++++++++++ drivers/rpmsg/rpmsg_core.c | 39 +++++++++++++++++++++++++++++++ 2 files changed, 59 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-rpmsg b/Documentation/ABI/testing/sysfs-bus-rpmsg index 189e419..1c8599e 100644 --- a/Documentation/ABI/testing/sysfs-bus-rpmsg +++ b/Documentation/ABI/testing/sysfs-bus-rpmsg @@ -73,3 +73,23 @@ Description: This sysfs entry tells us whether the channel is a local server channel that is announced (values are either true or false). + +What: /sys/bus/rpmsg/devices/.../driver_override +Date: March 2018 +KernelVersion: 4.17 +Contact: Ohad Ben-Cohen +Description: + Every rpmsg device is a communication channel with a remote + processor. Channels are identified by a textual name (see + /sys/bus/rpmsg/devices/.../name above) and have a local + ("source") rpmsg address, and remote ("destination") rpmsg + address. + + The listening entity (or client) which communicates with a + remote processor is referred as rpmsg driver. The rpmsg device + and rpmsg driver are matched based on rpmsg device name and + rpmsg driver ID table. + + This sysfs entry allows the rpmsg driver for a rpmsg device + to be specified which will override standard OF, ID table + and name matching. diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c index 5a08176..3e71976 100644 --- a/drivers/rpmsg/rpmsg_core.c +++ b/drivers/rpmsg/rpmsg_core.c @@ -333,11 +333,49 @@ field##_show(struct device *dev, \ } \ static DEVICE_ATTR_RO(field); +#define rpmsg_string_attr(field, member) \ +static ssize_t \ +field##_store(struct device *dev, struct device_attribute *attr, \ + const char *buf, size_t sz) \ +{ \ + struct rpmsg_device *rpdev = to_rpmsg_device(dev); \ + char *new, *old; \ + \ + new = kstrndup(buf, sz, GFP_KERNEL); \ + if (!new) \ + return -ENOMEM; \ + new[strcspn(new, "\n")] = '\0'; \ + \ + device_lock(dev); \ + old = rpdev->member; \ + if (strlen(new)) { \ + rpdev->member = new; \ + } else { \ + kfree(new); \ + rpdev->member = NULL; \ + } \ + device_unlock(dev); \ + \ + kfree(old); \ + \ + return sz; \ +} \ +static ssize_t \ +field##_show(struct device *dev, \ + struct device_attribute *attr, char *buf) \ +{ \ + struct rpmsg_device *rpdev = to_rpmsg_device(dev); \ + \ + return sprintf(buf, "%s\n", rpdev->member); \ +} \ +static DEVICE_ATTR_RW(field) + /* for more info, see Documentation/ABI/testing/sysfs-bus-rpmsg */ rpmsg_show_attr(name, id.name, "%s\n"); rpmsg_show_attr(src, src, "0x%x\n"); rpmsg_show_attr(dst, dst, "0x%x\n"); rpmsg_show_attr(announce, announce ? "true" : "false", "%s\n"); +rpmsg_string_attr(driver_override, driver_override); static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -359,6 +397,7 @@ static struct attribute *rpmsg_dev_attrs[] = { &dev_attr_dst.attr, &dev_attr_src.attr, &dev_attr_announce.attr, + &dev_attr_driver_override.attr, NULL, }; ATTRIBUTE_GROUPS(rpmsg_dev);