[PATCH v4 02/15] media: aptina-pll: Add comment documenting the PLL chain

[Hans de Goede <johannes.goede@oss.qualcomm.com>]

Add a code-comment documenting the PLL chain, this is a verbatim
copy of Laurent's ASCII-art PLL chain from the mailinglist.

Link: https://lore.kernel.org/linux-media/20250629204655.GA2059@pendragon.ideasonboard.com/
Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
---
Suggested-by: should really be Co-authored-by since I just copy and
pasted Laurent's comment from the list, but that requires Laurent's S-o-B.

Laurent can you give your S-o-B for adding a Co-authored-by ?
---
Changes in v4:
- New patch in v4 of this series
---
 drivers/media/i2c/aptina-pll.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/media/i2c/aptina-pll.c b/drivers/media/i2c/aptina-pll.c
index cd2ed4583c97ec87e516acfd249fdccf2f9efbb8..4a519ab587ba4cfb9945a1bb05e87a3b5e6d28c9 100644
--- a/drivers/media/i2c/aptina-pll.c
+++ b/drivers/media/i2c/aptina-pll.c
@@ -12,6 +12,16 @@
 
 #include "aptina-pll.h"
 
+/*
+ * Based on the docs the PLL is believed to have the following setup:
+ *
+ *         +-----+     +-----+     +-----+     +-----+     +-----+
+ * Fin --> | / N | --> | x M | --> | x 2 | --> | / P | --> | / 2 | -->
+ *         +-----+     +-----+     +-----+     +-----+     +-----+
+ *                                         fBit       fWord       fSensor
+ * ext_clock    int_clock   out_clock                             pix_clock
+ */
+
 int aptina_pll_calculate(struct device *dev,
 			 const struct aptina_pll_limits *limits,
 			 struct aptina_pll *pll)

-- 
2.52.0