drivers/clk/clk-max-gen.c

   1 /*
   2  * clk-max-gen.c - Generic clock driver for Maxim PMICs clocks
   3  *
   4  * Copyright (C) 2014 Google, Inc
   5  *
   6  * Copyright (C) 2012 Samsung Electornics
   7  * Jonghwa Lee <jonghwa3.lee@samsung.com>
   8  *
   9  * This program is free software; you can redistribute  it and/or modify it
  10  * under  the terms of  the GNU General  Public License as published by the
  11  * Free Software Foundation;  either version 2 of the  License, or (at your
  12  * option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * This driver is based on clk-max77686.c
  20  *
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/slab.h>
  25 #include <linux/err.h>
  26 #include <linux/regmap.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/clk-provider.h>
  29 #include <linux/mutex.h>
  30 #include <linux/clkdev.h>
  31 #include <linux/of.h>
  32 #include <linux/export.h>
  33
  34 struct max_gen_clk {
  35         struct regmap *regmap;
  36         u32 mask;
  37         u32 reg;
  38         struct clk_hw hw;
  39 };
  40
  41 static struct max_gen_clk *to_max_gen_clk(struct clk_hw *hw)
  42 {
  43         return container_of(hw, struct max_gen_clk, hw);
  44 }
  45
  46 static int max_gen_clk_prepare(struct clk_hw *hw)
  47 {
  48         struct max_gen_clk *max_gen = to_max_gen_clk(hw);
  49
  50         return regmap_update_bits(max_gen->regmap, max_gen->reg,
  51                                   max_gen->mask, max_gen->mask);
  52 }
  53
  54 static void max_gen_clk_unprepare(struct clk_hw *hw)
  55 {
  56         struct max_gen_clk *max_gen = to_max_gen_clk(hw);
  57
  58         regmap_update_bits(max_gen->regmap, max_gen->reg,
  59                            max_gen->mask, ~max_gen->mask);
  60 }
  61
  62 static int max_gen_clk_is_prepared(struct clk_hw *hw)
  63 {
  64         struct max_gen_clk *max_gen = to_max_gen_clk(hw);
  65         int ret;
  66         u32 val;
  67
  68         ret = regmap_read(max_gen->regmap, max_gen->reg, &val);
  69
  70         if (ret < 0)
  71                 return -EINVAL;
  72
  73         return val & max_gen->mask;
  74 }
  75
  76 static unsigned long max_gen_recalc_rate(struct clk_hw *hw,
  77                                          unsigned long parent_rate)
  78 {
  79         return 32768;
  80 }
  81
  82 struct clk_ops max_gen_clk_ops = {
  83         .prepare        = max_gen_clk_prepare,
  84         .unprepare      = max_gen_clk_unprepare,
  85         .is_prepared    = max_gen_clk_is_prepared,
  86         .recalc_rate    = max_gen_recalc_rate,
  87 };
  88 EXPORT_SYMBOL_GPL(max_gen_clk_ops);
  89
  90 static struct clk *max_gen_clk_register(struct device *dev,
  91                                         struct max_gen_clk *max_gen)
  92 {
  93         struct clk *clk;
  94         struct clk_hw *hw = &max_gen->hw;
  95         int ret;
  96
  97         clk = devm_clk_register(dev, hw);
  98         if (IS_ERR(clk))
  99                 return clk;
 100
 101         ret = clk_register_clkdev(clk, hw->init->name, NULL);
 102
 103         if (ret)
 104                 return ERR_PTR(ret);
 105
 106         return clk;
 107 }
 108
 109 int max_gen_clk_probe(struct platform_device *pdev, struct regmap *regmap,
 110                       u32 reg, struct clk_init_data *clks_init, int num_init)
 111 {
 112         int i, ret;
 113         struct max_gen_clk *max_gen_clks;
 114         struct clk **clocks;
 115         struct device *dev = pdev->dev.parent;
 116         const char *clk_name;
 117         struct clk_init_data *init;
 118
 119         clocks = devm_kzalloc(dev, sizeof(struct clk *) * num_init, GFP_KERNEL);
 120         if (!clocks)
 121                 return -ENOMEM;
 122
 123         max_gen_clks = devm_kzalloc(dev, sizeof(struct max_gen_clk)
 124                                     * num_init, GFP_KERNEL);
 125         if (!max_gen_clks)
 126                 return -ENOMEM;
 127
 128         for (i = 0; i < num_init; i++) {
 129                 max_gen_clks[i].regmap = regmap;
 130                 max_gen_clks[i].mask = 1 << i;
 131                 max_gen_clks[i].reg = reg;
 132
 133                 init = devm_kzalloc(dev, sizeof(*init), GFP_KERNEL);
 134                 if (!init)
 135                         return -ENOMEM;
 136
 137                 if (dev->of_node &&
 138                     !of_property_read_string_index(dev->of_node,
 139                                                    "clock-output-names",
 140                                                    i, &clk_name))
 141                         init->name = clk_name;
 142                 else
 143                         init->name = clks_init[i].name;
 144
 145                 init->ops = clks_init[i].ops;
 146                 init->flags = clks_init[i].flags;
 147
 148                 max_gen_clks[i].hw.init = init;
 149
 150                 clocks[i] = max_gen_clk_register(dev, &max_gen_clks[i]);
 151                 if (IS_ERR(clocks[i])) {
 152                         ret = PTR_ERR(clocks[i]);
 153                         dev_err(dev, "failed to register %s\n",
 154                                 max_gen_clks[i].hw.init->name);
 155                         return ret;
 156                 }
 157         }
 158
 159         platform_set_drvdata(pdev, clocks);
 160
 161         if (dev->of_node) {
 162                 struct clk_onecell_data *of_data;
 163
 164                 of_data = devm_kzalloc(dev, sizeof(*of_data), GFP_KERNEL);
 165                 if (!of_data)
 166                         return -ENOMEM;
 167
 168                 of_data->clks = clocks;
 169                 of_data->clk_num = num_init;
 170                 ret = of_clk_add_provider(dev->of_node, of_clk_src_onecell_get,
 171                                           of_data);
 172
 173                 if (ret) {
 174                         dev_err(dev, "failed to register OF clock provider\n");
 175                         return ret;
 176                 }
 177         }
 178
 179         return 0;
 180 }
 181 EXPORT_SYMBOL_GPL(max_gen_clk_probe);
 182
 183 int max_gen_clk_remove(struct platform_device *pdev, int num_init)
 184 {
 185         struct device *dev = pdev->dev.parent;
 186
 187         if (dev->of_node)
 188                 of_clk_del_provider(dev->of_node);
 189
 190         return 0;
 191 }
 192 EXPORT_SYMBOL_GPL(max_gen_clk_remove);