drivers/clk/mxs/clk-pll.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright 2012 Freescale Semiconductor, Inc.
   4  */
   5
   6 #include <linux/clk-provider.h>
   7 #include <linux/delay.h>
   8 #include <linux/err.h>
   9 #include <linux/io.h>
  10 #include <linux/slab.h>
  11 #include "clk.h"
  12
  13 /**
  14  * struct clk_pll - mxs pll clock
  15  * @hw: clk_hw for the pll
  16  * @base: base address of the pll
  17  * @power: the shift of power bit
  18  * @rate: the clock rate of the pll
  19  *
  20  * The mxs pll is a fixed rate clock with power and gate control,
  21  * and the shift of gate bit is always 31.
  22  */
  23 struct clk_pll {
  24         struct clk_hw hw;
  25         void __iomem *base;
  26         u8 power;
  27         unsigned long rate;
  28 };
  29
  30 #define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw)
  31
  32 static int clk_pll_prepare(struct clk_hw *hw)
  33 {
  34         struct clk_pll *pll = to_clk_pll(hw);
  35
  36         writel_relaxed(1 << pll->power, pll->base + SET);
  37
  38         udelay(10);
  39
  40         return 0;
  41 }
  42
  43 static void clk_pll_unprepare(struct clk_hw *hw)
  44 {
  45         struct clk_pll *pll = to_clk_pll(hw);
  46
  47         writel_relaxed(1 << pll->power, pll->base + CLR);
  48 }
  49
  50 static int clk_pll_enable(struct clk_hw *hw)
  51 {
  52         struct clk_pll *pll = to_clk_pll(hw);
  53
  54         writel_relaxed(1 << 31, pll->base + CLR);
  55
  56         return 0;
  57 }
  58
  59 static void clk_pll_disable(struct clk_hw *hw)
  60 {
  61         struct clk_pll *pll = to_clk_pll(hw);
  62
  63         writel_relaxed(1 << 31, pll->base + SET);
  64 }
  65
  66 static unsigned long clk_pll_recalc_rate(struct clk_hw *hw,
  67                                          unsigned long parent_rate)
  68 {
  69         struct clk_pll *pll = to_clk_pll(hw);
  70
  71         return pll->rate;
  72 }
  73
  74 static const struct clk_ops clk_pll_ops = {
  75         .prepare = clk_pll_prepare,
  76         .unprepare = clk_pll_unprepare,
  77         .enable = clk_pll_enable,
  78         .disable = clk_pll_disable,
  79         .recalc_rate = clk_pll_recalc_rate,
  80 };
  81
  82 struct clk *mxs_clk_pll(const char *name, const char *parent_name,
  83                         void __iomem *base, u8 power, unsigned long rate)
  84 {
  85         struct clk_pll *pll;
  86         struct clk *clk;
  87         struct clk_init_data init;
  88
  89         pll = kzalloc(sizeof(*pll), GFP_KERNEL);
  90         if (!pll)
  91                 return ERR_PTR(-ENOMEM);
  92
  93         init.name = name;
  94         init.ops = &clk_pll_ops;
  95         init.flags = 0;
  96         init.parent_names = (parent_name ? &parent_name: NULL);
  97         init.num_parents = (parent_name ? 1 : 0);
  98
  99         pll->base = base;
 100         pll->rate = rate;
 101         pll->power = power;
 102         pll->hw.init = &init;
 103
 104         clk = clk_register(NULL, &pll->hw);
 105         if (IS_ERR(clk))
 106                 kfree(pll);
 107
 108         return clk;
 109 }