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/clk-private.h>
  12 #include <linux/slab.h>
  13 #include <linux/io.h>
  14 #include <linux/err.h>
  15 #include <linux/types.h>
  16
  17 #include "clk.h"
  18
  19 #define PRCC_PCKEN                      0x000
  20 #define PRCC_PCKDIS                     0x004
  21 #define PRCC_KCKEN                      0x008
  22 #define PRCC_KCKDIS                     0x00C
  23 #define PRCC_PCKSR                      0x010
  24 #define PRCC_KCKSR                      0x014
  25
  26 #define to_clk_prcc(_hw) container_of(_hw, struct clk_prcc, hw)
  27
  28 struct clk_prcc {
  29         struct clk_hw hw;
  30         void __iomem *base;
  31         u32 cg_sel;
  32         int is_enabled;
  33 };
  34
  35 /* PRCC clock operations. */
  36
  37 static int clk_prcc_pclk_enable(struct clk_hw *hw)
  38 {
  39         struct clk_prcc *clk = to_clk_prcc(hw);
  40
  41         writel(clk->cg_sel, (clk->base + PRCC_PCKEN));
  42         while (!(readl(clk->base + PRCC_PCKSR) & clk->cg_sel))
  43                 cpu_relax();
  44
  45         clk->is_enabled = 1;
  46         return 0;
  47 }
  48
  49 static void clk_prcc_pclk_disable(struct clk_hw *hw)
  50 {
  51         struct clk_prcc *clk = to_clk_prcc(hw);
  52
  53         writel(clk->cg_sel, (clk->base + PRCC_PCKDIS));
  54         clk->is_enabled = 0;
  55 }
  56
  57 static int clk_prcc_kclk_enable(struct clk_hw *hw)
  58 {
  59         struct clk_prcc *clk = to_clk_prcc(hw);
  60
  61         writel(clk->cg_sel, (clk->base + PRCC_KCKEN));
  62         while (!(readl(clk->base + PRCC_KCKSR) & clk->cg_sel))
  63                 cpu_relax();
  64
  65         clk->is_enabled = 1;
  66         return 0;
  67 }
  68
  69 static void clk_prcc_kclk_disable(struct clk_hw *hw)
  70 {
  71         struct clk_prcc *clk = to_clk_prcc(hw);
  72
  73         writel(clk->cg_sel, (clk->base + PRCC_KCKDIS));
  74         clk->is_enabled = 0;
  75 }
  76
  77 static int clk_prcc_is_enabled(struct clk_hw *hw)
  78 {
  79         struct clk_prcc *clk = to_clk_prcc(hw);
  80         return clk->is_enabled;
  81 }
  82
  83 static struct clk_ops clk_prcc_pclk_ops = {
  84         .enable = clk_prcc_pclk_enable,
  85         .disable = clk_prcc_pclk_disable,
  86         .is_enabled = clk_prcc_is_enabled,
  87 };
  88
  89 static struct clk_ops clk_prcc_kclk_ops = {
  90         .enable = clk_prcc_kclk_enable,
  91         .disable = clk_prcc_kclk_disable,
  92         .is_enabled = clk_prcc_is_enabled,
  93 };
  94
  95 static struct clk *clk_reg_prcc(const char *name,
  96                                 const char *parent_name,
  97                                 resource_size_t phy_base,
  98                                 u32 cg_sel,
  99                                 unsigned long flags,
 100                                 struct clk_ops *clk_prcc_ops)
 101 {
 102         struct clk_prcc *clk;
 103         struct clk_init_data clk_prcc_init;
 104         struct clk *clk_reg;
 105
 106         if (!name) {
 107                 pr_err("clk_prcc: %s invalid arguments passed\n", __func__);
 108                 return ERR_PTR(-EINVAL);
 109         }
 110
 111         clk = kzalloc(sizeof(struct clk_prcc), GFP_KERNEL);
 112         if (!clk) {
 113                 pr_err("clk_prcc: %s could not allocate clk\n", __func__);
 114                 return ERR_PTR(-ENOMEM);
 115         }
 116
 117         clk->base = ioremap(phy_base, SZ_4K);
 118         if (!clk->base)
 119                 goto free_clk;
 120
 121         clk->cg_sel = cg_sel;
 122         clk->is_enabled = 1;
 123
 124         clk_prcc_init.name = name;
 125         clk_prcc_init.ops = clk_prcc_ops;
 126         clk_prcc_init.flags = flags;
 127         clk_prcc_init.parent_names = (parent_name ? &parent_name : NULL);
 128         clk_prcc_init.num_parents = (parent_name ? 1 : 0);
 129         clk->hw.init = &clk_prcc_init;
 130
 131         clk_reg = clk_register(NULL, &clk->hw);
 132         if (IS_ERR_OR_NULL(clk_reg))
 133                 goto unmap_clk;
 134
 135         return clk_reg;
 136
 137 unmap_clk:
 138         iounmap(clk->base);
 139 free_clk:
 140         kfree(clk);
 141         pr_err("clk_prcc: %s failed to register clk\n", __func__);
 142         return ERR_PTR(-ENOMEM);
 143 }
 144
 145 struct clk *clk_reg_prcc_pclk(const char *name,
 146                               const char *parent_name,
 147                               resource_size_t phy_base,
 148                               u32 cg_sel,
 149                               unsigned long flags)
 150 {
 151         return clk_reg_prcc(name, parent_name, phy_base, cg_sel, flags,
 152                         &clk_prcc_pclk_ops);
 153 }
 154
 155 struct clk *clk_reg_prcc_kclk(const char *name,
 156                               const char *parent_name,
 157                               resource_size_t phy_base,
 158                               u32 cg_sel,
 159                               unsigned long flags)
 160 {
 161         return clk_reg_prcc(name, parent_name, phy_base, cg_sel, flags,
 162                         &clk_prcc_kclk_ops);
 163 }