From patchwork Fri Apr 3 09:11:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 210329 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7AEF7C2BA1A for ; Fri, 3 Apr 2020 09:12:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5991220787 for ; Fri, 3 Apr 2020 09:12:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390609AbgDCJMA (ORCPT ); Fri, 3 Apr 2020 05:12:00 -0400 Received: from retiisi.org.uk ([95.216.213.190]:49912 "EHLO hillosipuli.retiisi.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388221AbgDCJL7 (ORCPT ); Fri, 3 Apr 2020 05:11:59 -0400 Received: from lanttu.localdomain (lanttu.retiisi.org.uk [IPv6:2a01:4f9:c010:4572::c1:2]) by hillosipuli.retiisi.org.uk (Postfix) with ESMTP id E54F6634C8B; Fri, 3 Apr 2020 12:11:07 +0300 (EEST) From: Sakari Ailus To: Petr Mladek Cc: Andy Shevchenko , linux-media@vger.kernel.org, Dave Stevenson , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, hverkuil@xs4all.nl, laurent.pinchart@ideasonboard.com, mchehab@kernel.org, Sergey Senozhatsky , Steven Rostedt , Joe Perches , Jani Nikula Subject: [PATCH v2 1/1] lib/vsprintf: Add support for printing V4L2 and DRM fourccs Date: Fri, 3 Apr 2020 12:11:56 +0300 Message-Id: <20200403091156.7814-1-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Add a printk modifier %ppf (for pixel format) for printing V4L2 and DRM pixel formats denoted by 4ccs. The 4cc encoding is the same for both so the same implementation can be used. Suggested-by: Mauro Carvalho Chehab Signed-off-by: Sakari Ailus --- since v1: - Improve documentation (add -BE suffix, refer to "FourCC". - Use '%p4cc' conversion specifier instead of '%ppf'. - Fix 31st bit handling in printing FourCC codes. - Use string() correctly, to allow e.g. proper field width handling. - Remove loop, use put_unaligned_le32() instead. Documentation/core-api/printk-formats.rst | 12 +++++++++++ lib/vsprintf.c | 25 +++++++++++++++++++++++ 2 files changed, 37 insertions(+) diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst index 8ebe46b1af39..550568520ab6 100644 --- a/Documentation/core-api/printk-formats.rst +++ b/Documentation/core-api/printk-formats.rst @@ -545,6 +545,18 @@ For printing netdev_features_t. Passed by reference. +V4L2 and DRM FourCC code (pixel format) +--------------------------------------- + +:: + + %p4cc + +Print a FourCC code used by V4L2 or DRM. The "-BE" suffix is added on big endian +formats. + +Passed by reference. + Thanks ====== diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 7c488a1ce318..93eea6a320da 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1721,6 +1721,28 @@ char *netdev_bits(char *buf, char *end, const void *addr, return special_hex_number(buf, end, num, size); } +static noinline_for_stack +char *fourcc_string(char *buf, char *end, const u32 *fourcc, + struct printf_spec spec, const char *fmt) +{ +#define FOURCC_STRING_BE "-BE" + char s[sizeof(*fourcc) + sizeof(FOURCC_STRING_BE)] = { 0 }; + + if (check_pointer(&buf, end, fourcc, spec)) + return buf; + + if (fmt[1] != 'c' || fmt[2] != 'c') + return error_string(buf, end, "(%p4?)", spec); + + put_unaligned_le32(*fourcc & ~BIT(31), s); + + if (*fourcc & BIT(31)) + strscpy(s + sizeof(*fourcc), FOURCC_STRING_BE, + sizeof(FOURCC_STRING_BE)); + + return string(buf, end, s, spec); +} + static noinline_for_stack char *address_val(char *buf, char *end, const void *addr, struct printf_spec spec, const char *fmt) @@ -2131,6 +2153,7 @@ char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, * correctness of the format string and va_list arguments. * - 'K' For a kernel pointer that should be hidden from unprivileged users * - 'NF' For a netdev_features_t + * - '4cc' V4L2 or DRM FourCC code, with "-BE" suffix on big endian formats. * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with * a certain separator (' ' by default): * C colon @@ -2223,6 +2246,8 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, return restricted_pointer(buf, end, ptr, spec); case 'N': return netdev_bits(buf, end, ptr, spec, fmt); + case '4': + return fourcc_string(buf, end, ptr, spec, fmt); case 'a': return address_val(buf, end, ptr, spec, fmt); case 'd':