lib/vsprintf: add %pC{,n,r} format specifiers for clocks

Add format specifiers for printing struct clk:
  - '%pC' or '%pCn': name (Common Clock Framework) or address (legacy
    clock framework) of the clock,
  - '%pCr': rate of the clock.

[akpm@linux-foundation.org: omit code if !CONFIG_HAVE_CLK]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 56804e40cb18..cb6a596072bb 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -261,6 +261,18 @@ struct va_format:
 
 	Passed by reference.
 
+struct clk:
+
+	%pC	pll1
+	%pCn	pll1
+	%pCr	1560000000
+
+	For printing struct clk structures. '%pC' and '%pCn' print the name
+	(Common Clock Framework) or address (legacy clock framework) of the
+	structure; '%pCr' prints the current clock rate.
+
+	Passed by reference.
+
 
 Thank you for your cooperation and attention.