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authorSakari Ailus <sakari.ailus@linux.intel.com>2021-02-16 18:57:20 +0300
committerThomas Zimmermann <tzimmermann@suse.de>2021-02-17 14:52:20 +0300
commitaf612e43de6d27df51a7636229be7d33fe3ab7b5 (patch)
treea84a7181fd4374fbe5071b9c41dde8afc26c91e1 /lib/vsprintf.c
parent4d36cf070249564546f07a3fe5456e29dbbc1593 (diff)
downloadlinux-af612e43de6d27df51a7636229be7d33fe3ab7b5.tar.xz
lib/vsprintf: Add support for printing V4L2 and DRM fourccs
Add a printk modifier %p4cc (for pixel format) for printing V4L2 and DRM pixel formats denoted by fourccs. The fourcc 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> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20210216155723.17109-2-sakari.ailus@linux.intel.com
Diffstat (limited to 'lib/vsprintf.c')
-rw-r--r--lib/vsprintf.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 3b53c73580c5..62c7224a5076 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1734,6 +1734,42 @@ char *netdev_bits(char *buf, char *end, const void *addr,
}
static noinline_for_stack
+char *fourcc_string(char *buf, char *end, const u32 *fourcc,
+ struct printf_spec spec, const char *fmt)
+{
+ char output[sizeof("0123 little-endian (0x01234567)")];
+ char *p = output;
+ unsigned int i;
+ u32 val;
+
+ if (fmt[1] != 'c' || fmt[2] != 'c')
+ return error_string(buf, end, "(%p4?)", spec);
+
+ if (check_pointer(&buf, end, fourcc, spec))
+ return buf;
+
+ val = *fourcc & ~BIT(31);
+
+ for (i = 0; i < sizeof(*fourcc); i++) {
+ unsigned char c = val >> (i * 8);
+
+ /* Print non-control ASCII characters as-is, dot otherwise */
+ *p++ = isascii(c) && isprint(c) ? c : '.';
+ }
+
+ strcpy(p, *fourcc & BIT(31) ? " big-endian" : " little-endian");
+ p += strlen(p);
+
+ *p++ = ' ';
+ *p++ = '(';
+ p = special_hex_number(p, output + sizeof(output) - 2, *fourcc, sizeof(u32));
+ *p++ = ')';
+ *p = '\0';
+
+ return string(buf, end, output, spec);
+}
+
+static noinline_for_stack
char *address_val(char *buf, char *end, const void *addr,
struct printf_spec spec, const char *fmt)
{
@@ -2162,6 +2198,7 @@ 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 endianness and raw numerical value.
* - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
* a certain separator (' ' by default):
* C colon
@@ -2259,6 +2296,8 @@ 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':