clk: at91: clk-master: add notifier for divider

SAMA7G5 supports DVFS by changing cpuck. On SAMA7G5 mck0 shares the same
parent with cpuck as seen in the following clock tree:

                       +----------> cpuck
                       |
FRAC PLL ---> DIV PLL -+-> DIV ---> mck0

mck0 could go b/w 32KHz and 200MHz on SAMA7G5. To avoid mck0 overclocking
while changing FRAC PLL or DIV PLL the commit implements a notifier for
mck0 which applies a safe divider to register (maximum value of the divider
which is 5) on PRE_RATE_CHANGE events (such that changes on PLL to not
overclock mck0) and sets the maximum allowed rate on POST_RATE_CHANGE
events.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20211011112719.3951784-13-claudiu.beznea@microchip.com
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
index 207ecccef29f..3a1bf6194c28 100644
--- a/drivers/clk/at91/pmc.h
+++ b/drivers/clk/at91/pmc.h
@@ -182,7 +182,7 @@ at91_clk_register_master_div(struct regmap *regmap, const char *name,
 			     const char *parent_names,
 			     const struct clk_master_layout *layout,
 			     const struct clk_master_characteristics *characteristics,
-			     spinlock_t *lock, u32 flags);
+			     spinlock_t *lock, u32 flags, u32 safe_div);
 
 struct clk_hw * __init
 at91_clk_sama7g5_register_master(struct regmap *regmap,