target/linux/bcm27xx/patches-5.15/950-0865-clk-Add-clk_get_rate_range.patch

   1 From 1008f7a86f470914e78a54a2a75cf8bbc8b8f9db Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime@cerno.tech>
   3 Date: Fri, 15 Apr 2022 14:17:41 +0200
   4 Subject: [PATCH] clk: Add clk_get_rate_range
   5
   6 With the recent introduction of clock drivers that will force their
   7 clock rate to either the minimum or maximum boundaries, it becomes
   8 harder for clock users to discover either boundary of their clock.
   9
  10 Indeed, the best way to do that previously was to call clk_round_rate()
  11 on either 0 or ULONG_MAX and count on the driver to clamp the rate to
  12 the current boundary, but that won't work anymore.
  13
  14 Since any other alternative (calling clk_set_rate_range() and looking at
  15 the returned value, calling clk_round_rate() still, or just doing
  16 nothing) depends on how the driver will behaves, we actually are
  17 punching a hole through the abstraction provided by the clock framework.
  18
  19 In order to avoid any abstraction violation, let's create a bunch of
  20 accessors that will return the current minimum and maximum for a given
  21 clock.
  22
  23 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  24 ---
  25  drivers/clk/clk.c   | 18 ++++++++++++++
  26  include/linux/clk.h | 59 +++++++++++++++++++++++++++++++++++++++++++++
  27  2 files changed, 77 insertions(+)
  28
  29 --- a/drivers/clk/clk.c
  30 +++ b/drivers/clk/clk.c
  31 @@ -2576,6 +2576,24 @@ int clk_set_max_rate(struct clk *clk, un
  32  EXPORT_SYMBOL_GPL(clk_set_max_rate);
  33
  34  /**
  35 + * clk_get_rate_range - returns the clock rate range for a clock source
  36 + * @clk: clock source
  37 + * @min: Pointer to the variable that will hold the minimum
  38 + * @max: Pointer to the variable that will hold the maximum
  39 + *
  40 + * Fills the @min and @max variables with the minimum and maximum that
  41 + * the clock source can reach.
  42 + */
  43 +void clk_get_rate_range(struct clk *clk, unsigned long *min, unsigned long *max)
  44 +{
  45 +       if (!clk || !min || !max)
  46 +               return;
  47 +
  48 +       clk_core_get_boundaries(clk->core, min, max);
  49 +}
  50 +EXPORT_SYMBOL_GPL(clk_get_rate_range);
  51 +
  52 +/**
  53   * clk_get_parent - return the parent of a clk
  54   * @clk: the clk whose parent gets returned
  55   *
  56 --- a/include/linux/clk.h
  57 +++ b/include/linux/clk.h
  58 @@ -714,6 +714,17 @@ bool clk_has_parent(struct clk *clk, str
  59  int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max);
  60
  61  /**
  62 + * clk_get_rate_range - returns the clock rate range for a clock source
  63 + * @clk: clock source
  64 + * @min: Pointer to the variable that will hold the minimum
  65 + * @max: Pointer to the variable that will hold the maximum
  66 + *
  67 + * Fills the @min and @max variables with the minimum and maximum that
  68 + * the clock source can reach.
  69 + */
  70 +void clk_get_rate_range(struct clk *clk, unsigned long *min, unsigned long *max);
  71 +
  72 +/**
  73   * clk_set_min_rate - set a minimum clock rate for a clock source
  74   * @clk: clock source
  75   * @rate: desired minimum clock rate in Hz, inclusive
  76 @@ -909,6 +920,16 @@ static inline int clk_set_rate_range(str
  77         return 0;
  78  }
  79
  80 +static inline void clk_get_rate_range(struct clk *clk, unsigned long *min,
  81 +                                     unsigned long *max)
  82 +{
  83 +       if (!min || !max)
  84 +               return;
  85 +
  86 +       *min = 0;
  87 +       *max = ULONG_MAX;
  88 +}
  89 +
  90  static inline int clk_set_min_rate(struct clk *clk, unsigned long rate)
  91  {
  92         return 0;
  93 @@ -999,6 +1020,44 @@ static inline int clk_drop_range(struct
  94  }
  95
  96  /**
  97 + * clk_get_min_rate - returns the minimum clock rate for a clock source
  98 + * @clk: clock source
  99 + *
 100 + * Returns either the minimum clock rate in Hz that clock source can
 101 + * reach, or 0 on error.
 102 + */
 103 +static inline unsigned long clk_get_min_rate(struct clk *clk)
 104 +{
 105 +       unsigned long min, max;
 106 +
 107 +       if (!clk)
 108 +               return 0;
 109 +
 110 +       clk_get_rate_range(clk, &min, &max);
 111 +
 112 +       return min;
 113 +}
 114 +
 115 +/**
 116 + * clk_get_max_rate - returns the maximum clock rate for a clock source
 117 + * @clk: clock source
 118 + *
 119 + * Returns either the maximum clock rate in Hz that clock source can
 120 + * reach, or 0 on error.
 121 + */
 122 +static inline unsigned long clk_get_max_rate(struct clk *clk)
 123 +{
 124 +       unsigned long min, max;
 125 +
 126 +       if (!clk)
 127 +               return 0;
 128 +
 129 +       clk_get_rate_range(clk, &min, &max);
 130 +
 131 +       return max;
 132 +}
 133 +
 134 +/**
 135   * clk_get_optional - lookup and obtain a reference to an optional clock
 136   *                   producer.
 137   * @dev: device for clock "consumer"