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 mchehab@kernel.org Signed-off-by: Sakari Ailus sakari.ailus@linux.intel.com --- Documentation/core-api/printk-formats.rst | 11 +++++++++ lib/vsprintf.c | 29 +++++++++++++++++++++++ 2 files changed, 40 insertions(+)
diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst index 8ebe46b1af39..b6249f513c09 100644 --- a/Documentation/core-api/printk-formats.rst +++ b/Documentation/core-api/printk-formats.rst @@ -545,6 +545,17 @@ For printing netdev_features_t.
Passed by reference.
+V4L2 and DRM fourcc code (pixel format) +--------------------------------------- + +:: + + %ppf + +Print a 4cc code used by V4L2 or DRM. + +Passed by reference. + Thanks ======
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 7c488a1ce318..b39f0ac317c5 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1721,6 +1721,32 @@ char *netdev_bits(char *buf, char *end, const void *addr, return special_hex_number(buf, end, num, size); }
+static noinline_for_stack +char *pixel_format_string(char *buf, char *end, const u32 *fourcc, + struct printf_spec spec, const char *fmt) +{ + char ch[2] = { 0 }; + unsigned int i; + + if (check_pointer(&buf, end, fourcc, spec)) + return buf; + + switch (fmt[1]) { + case 'f': + for (i = 0; i < sizeof(*fourcc); i++) { + ch[0] = *fourcc >> (i << 3); + buf = string(buf, end, ch, spec); + } + + if (*fourcc & BIT(31)) + buf = string(buf, end, "-BE", spec); + + return buf; + default: + return error_string(buf, end, "(%pp?)", spec); + } +} + static noinline_for_stack char *address_val(char *buf, char *end, const void *addr, struct printf_spec spec, const char *fmt) @@ -2131,6 +2157,7 @@ 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 + * - 'pf' V4L2 or DRM pixel format. * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with * a certain separator (' ' by default): * C colon @@ -2223,6 +2250,8 @@ 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 'p': + return pixel_format_string(buf, end, ptr, spec, fmt); case 'a': return address_val(buf, end, ptr, spec, fmt); case 'd':