clk: Add rate constraints to clocks

Adds a way for clock consumers to set maximum and minimum rates. This
can be used for thermal drivers to set minimum rates, or by misc.
drivers to set maximum rates to assure a minimum performance level.

Changes the signature of the determine_rate callback by adding the
parameters min_rate and max_rate.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
[sboyd@codeaurora.org: set req_rate in __clk_init]
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: min/max rate for sun6i_ahb1_clk_determine_rate
                        migrated clk-private.h changes to clk.c]
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 12f13b0..17dd6e9 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -175,9 +175,12 @@
 					unsigned long parent_rate);
 	long		(*round_rate)(struct clk_hw *hw, unsigned long rate,
 					unsigned long *parent_rate);
-	long		(*determine_rate)(struct clk_hw *hw, unsigned long rate,
-					unsigned long *best_parent_rate,
-					struct clk_hw **best_parent_hw);
+	long		(*determine_rate)(struct clk_hw *hw,
+					  unsigned long rate,
+					  unsigned long min_rate,
+					  unsigned long max_rate,
+					  unsigned long *best_parent_rate,
+					  struct clk_hw **best_parent_hw);
 	int		(*set_parent)(struct clk_hw *hw, u8 index);
 	u8		(*get_parent)(struct clk_hw *hw);
 	int		(*set_rate)(struct clk_hw *hw, unsigned long rate,
@@ -573,9 +576,17 @@
 bool __clk_is_enabled(struct clk *clk);
 struct clk *__clk_lookup(const char *name);
 long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate,
+			      unsigned long min_rate,
+			      unsigned long max_rate,
 			      unsigned long *best_parent_rate,
 			      struct clk_hw **best_parent_p);
+unsigned long __clk_determine_rate(struct clk_hw *core,
+				   unsigned long rate,
+				   unsigned long min_rate,
+				   unsigned long max_rate);
 long __clk_mux_determine_rate_closest(struct clk_hw *hw, unsigned long rate,
+			      unsigned long min_rate,
+			      unsigned long max_rate,
 			      unsigned long *best_parent_rate,
 			      struct clk_hw **best_parent_p);