kernel/drivers/clk/ux500/clk-prcc.c

   1 /*
   2  * PRCC clock implementation for ux500 platform.
   3  *
   4  * Copyright (C) 2012 ST-Ericsson SA
   5  * Author: Ulf Hansson <ulf.hansson@linaro.org>
   6  *
   7  * License terms: GNU General Public License (GPL) version 2
   8  */
   9
  10 #include <linux/clk-provider.h>
  11 #include <linux/slab.h>
  12 #include <linux/io.h>
  13 #include <linux/err.h>
  14 #include <linux/types.h>
  15
  16 #include "clk.h"
  17
  18 #define PRCC_PCKEN                      0x000
  19 #define PRCC_PCKDIS                     0x004
  20 #define PRCC_KCKEN                      0x008
  21 #define PRCC_KCKDIS                     0x00C
  22 #define PRCC_PCKSR                      0x010
  23 #define PRCC_KCKSR                      0x014
  24
  25 #define to_clk_prcc(_hw) container_of(_hw, struct clk_prcc, hw)
  26
  27 struct clk_prcc {
  28         struct clk_hw hw;
  29         void __iomem *base;
  30         u32 cg_sel;
  31         int is_enabled;
  32 };
  33
  34 /* PRCC clock operations. */
  35
  36 static int clk_prcc_pclk_enable(struct clk_hw *hw)
  37 {
  38         struct clk_prcc *clk = to_clk_prcc(hw);
  39
  40         writel(clk->cg_sel, (clk->base + PRCC_PCKEN));
  41         while (!(readl(clk->base + PRCC_PCKSR) & clk->cg_sel))
  42                 cpu_relax();
  43
  44         clk->is_enabled = 1;
  45         return 0;
  46 }
  47
  48 static void clk_prcc_pclk_disable(struct clk_hw *hw)
  49 {
  50         struct clk_prcc *clk = to_clk_prcc(hw);
  51
  52         writel(clk->cg_sel, (clk->base + PRCC_PCKDIS));
  53         clk->is_enabled = 0;
  54 }
  55
  56 static int clk_prcc_kclk_enable(struct clk_hw *hw)
  57 {
  58         struct clk_prcc *clk = to_clk_prcc(hw);
  59
  60         writel(clk->cg_sel, (clk->base + PRCC_KCKEN));
  61         while (!(readl(clk->base + PRCC_KCKSR) & clk->cg_sel))
  62                 cpu_relax();
  63
  64         clk->is_enabled = 1;
  65         return 0;
  66 }
  67
  68 static void clk_prcc_kclk_disable(struct clk_hw *hw)
  69 {
  70         struct clk_prcc *clk = to_clk_prcc(hw);
  71
  72         writel(clk->cg_sel, (clk->base + PRCC_KCKDIS));
  73         clk->is_enabled = 0;
  74 }
  75
  76 static int clk_prcc_is_enabled(struct clk_hw *hw)
  77 {
  78         struct clk_prcc *clk = to_clk_prcc(hw);
  79         return clk->is_enabled;
  80 }
  81
  82 static struct clk_ops clk_prcc_pclk_ops = {
  83         .enable = clk_prcc_pclk_enable,
  84         .disable = clk_prcc_pclk_disable,
  85         .is_enabled = clk_prcc_is_enabled,
  86 };
  87
  88 static struct clk_ops clk_prcc_kclk_ops = {
  89         .enable = clk_prcc_kclk_enable,
  90         .disable = clk_prcc_kclk_disable,
  91         .is_enabled = clk_prcc_is_enabled,
  92 };
  93
  94 static struct clk *clk_reg_prcc(const char *name,
  95                                 const char *parent_name,
  96                                 resource_size_t phy_base,
  97                                 u32 cg_sel,
  98                                 unsigned long flags,
  99                                 struct clk_ops *clk_prcc_ops)
 100 {
 101         struct clk_prcc *clk;
 102         struct clk_init_data clk_prcc_init;
 103         struct clk *clk_reg;
 104
 105         if (!name) {
 106                 pr_err("clk_prcc: %s invalid arguments passed\n", __func__);
 107                 return ERR_PTR(-EINVAL);
 108         }
 109
 110         clk = kzalloc(sizeof(struct clk_prcc), GFP_KERNEL);
 111         if (!clk) {
 112                 pr_err("clk_prcc: %s could not allocate clk\n", __func__);
 113                 return ERR_PTR(-ENOMEM);
 114         }
 115
 116         clk->base = ioremap(phy_base, SZ_4K);
 117         if (!clk->base)
 118                 goto free_clk;
 119
 120         clk->cg_sel = cg_sel;
 121         clk->is_enabled = 1;
 122
 123         clk_prcc_init.name = name;
 124         clk_prcc_init.ops = clk_prcc_ops;
 125         clk_prcc_init.flags = flags;
 126         clk_prcc_init.parent_names = (parent_name ? &parent_name : NULL);
 127         clk_prcc_init.num_parents = (parent_name ? 1 : 0);
 128         clk->hw.init = &clk_prcc_init;
 129
 130         clk_reg = clk_register(NULL, &clk->hw);
 131         if (IS_ERR_OR_NULL(clk_reg))
 132                 goto unmap_clk;
 133
 134         return clk_reg;
 135
 136 unmap_clk:
 137         iounmap(clk->base);
 138 free_clk:
 139         kfree(clk);
 140         pr_err("clk_prcc: %s failed to register clk\n", __func__);
 141         return ERR_PTR(-ENOMEM);
 142 }
 143
 144 struct clk *clk_reg_prcc_pclk(const char *name,
 145                               const char *parent_name,
 146                               resource_size_t phy_base,
 147                               u32 cg_sel,
 148                               unsigned long flags)
 149 {
 150         return clk_reg_prcc(name, parent_name, phy_base, cg_sel, flags,
 151                         &clk_prcc_pclk_ops);
 152 }
 153
 154 struct clk *clk_reg_prcc_kclk(const char *name,
 155                               const char *parent_name,
 156                               resource_size_t phy_base,
 157                               u32 cg_sel,
 158                               unsigned long flags)
 159 {
 160         return clk_reg_prcc(name, parent_name, phy_base, cg_sel, flags,
 161                         &clk_prcc_kclk_ops);
 162 }