clk: divider: read-only divider can propagate rate change

When a divider clock has CLK_DIVIDER_READ_ONLY set, it means that the
register shall be left un-touched, but it does not mean the clock
should stop rate propagation if CLK_SET_RATE_PARENT is set

This is properly handled in qcom clk-regmap-divider but it was not in
the generic divider

To fix this situation, introduce a new helper function
divider_ro_round_rate, on the same model as divider_round_rate.

Fixes: e6d5e7d90be9 ("clk-divider: Fix READ_ONLY when divider > 1")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Tested-By: David Lechner <david@lechnology.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index cb18526d69cb..210a890008f9 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -420,6 +420,10 @@ long divider_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
 			       unsigned long rate, unsigned long *prate,
 			       const struct clk_div_table *table,
 			       u8 width, unsigned long flags);
+long divider_ro_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
+				  unsigned long rate, unsigned long *prate,
+				  const struct clk_div_table *table, u8 width,
+				  unsigned long flags, unsigned int val);
 int divider_get_val(unsigned long rate, unsigned long parent_rate,
 		const struct clk_div_table *table, u8 width,
 		unsigned long flags);
@@ -780,6 +784,17 @@ static inline long divider_round_rate(struct clk_hw *hw, unsigned long rate,
 					 rate, prate, table, width, flags);
 }
 
+static inline long divider_ro_round_rate(struct clk_hw *hw, unsigned long rate,
+					 unsigned long *prate,
+					 const struct clk_div_table *table,
+					 u8 width, unsigned long flags,
+					 unsigned int val)
+{
+	return divider_ro_round_rate_parent(hw, clk_hw_get_parent(hw),
+					    rate, prate, table, width, flags,
+					    val);
+}
+
 /*
  * FIXME clock api without lock protection
  */