drivers/clk/clk-max77686.c

   1 /*
   2  * clk-max77686.c - Clock driver for Maxim 77686
   3  *
   4  * Copyright (C) 2012 Samsung Electornics
   5  * Jonghwa Lee <jonghwa3.lee@samsung.com>
   6  *
   7  * This program is free software; you can redistribute  it and/or modify it
   8  * under  the terms of  the GNU General  Public License as published by the
   9  * Free Software Foundation;  either version 2 of the  License, or (at your
  10  * option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  *
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/slab.h>
  25 #include <linux/err.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/mfd/max77686.h>
  28 #include <linux/mfd/max77686-private.h>
  29 #include <linux/clk-provider.h>
  30 #include <linux/mutex.h>
  31 #include <linux/clkdev.h>
  32
  33 enum {
  34         MAX77686_CLK_AP = 0,
  35         MAX77686_CLK_CP,
  36         MAX77686_CLK_PMIC,
  37         MAX77686_CLKS_NUM,
  38 };
  39
  40 struct max77686_clk {
  41         struct max77686_dev *iodev;
  42         u32 mask;
  43         struct clk_hw hw;
  44         struct clk_lookup *lookup;
  45 };
  46
  47 static struct max77686_clk *to_max77686_clk(struct clk_hw *hw)
  48 {
  49         return container_of(hw, struct max77686_clk, hw);
  50 }
  51
  52 static int max77686_clk_prepare(struct clk_hw *hw)
  53 {
  54         struct max77686_clk *max77686 = to_max77686_clk(hw);
  55
  56         return regmap_update_bits(max77686->iodev->regmap,
  57                                   MAX77686_REG_32KHZ, max77686->mask,
  58                                   max77686->mask);
  59 }
  60
  61 static void max77686_clk_unprepare(struct clk_hw *hw)
  62 {
  63         struct max77686_clk *max77686 = to_max77686_clk(hw);
  64
  65         regmap_update_bits(max77686->iodev->regmap,
  66                 MAX77686_REG_32KHZ, max77686->mask, ~max77686->mask);
  67 }
  68
  69 static int max77686_clk_is_prepared(struct clk_hw *hw)
  70 {
  71         struct max77686_clk *max77686 = to_max77686_clk(hw);
  72         int ret;
  73         u32 val;
  74
  75         ret = regmap_read(max77686->iodev->regmap,
  76                                 MAX77686_REG_32KHZ, &val);
  77
  78         if (ret < 0)
  79                 return -EINVAL;
  80
  81         return val & max77686->mask;
  82 }
  83
  84 static unsigned long max77686_recalc_rate(struct clk_hw *hw,
  85                                           unsigned long parent_rate)
  86 {
  87         return 32768;
  88 }
  89
  90 static struct clk_ops max77686_clk_ops = {
  91         .prepare        = max77686_clk_prepare,
  92         .unprepare      = max77686_clk_unprepare,
  93         .is_prepared    = max77686_clk_is_prepared,
  94         .recalc_rate    = max77686_recalc_rate,
  95 };
  96
  97 static struct clk_init_data max77686_clks_init[MAX77686_CLKS_NUM] = {
  98         [MAX77686_CLK_AP] = {
  99                 .name = "32khz_ap",
 100                 .ops = &max77686_clk_ops,
 101                 .flags = CLK_IS_ROOT,
 102         },
 103         [MAX77686_CLK_CP] = {
 104                 .name = "32khz_cp",
 105                 .ops = &max77686_clk_ops,
 106                 .flags = CLK_IS_ROOT,
 107         },
 108         [MAX77686_CLK_PMIC] = {
 109                 .name = "32khz_pmic",
 110                 .ops = &max77686_clk_ops,
 111                 .flags = CLK_IS_ROOT,
 112         },
 113 };
 114
 115 static struct clk *max77686_clk_register(struct device *dev,
 116                                 struct max77686_clk *max77686)
 117 {
 118         struct clk *clk;
 119         struct clk_hw *hw = &max77686->hw;
 120
 121         clk = clk_register(dev, hw);
 122         if (IS_ERR(clk))
 123                 return clk;
 124
 125         max77686->lookup = kzalloc(sizeof(struct clk_lookup), GFP_KERNEL);
 126         if (!max77686->lookup)
 127                 return ERR_PTR(-ENOMEM);
 128
 129         max77686->lookup->con_id = hw->init->name;
 130         max77686->lookup->clk = clk;
 131
 132         clkdev_add(max77686->lookup);
 133
 134         return clk;
 135 }
 136
 137 static int max77686_clk_probe(struct platform_device *pdev)
 138 {
 139         struct max77686_dev *iodev = dev_get_drvdata(pdev->dev.parent);
 140         struct max77686_clk *max77686_clks[MAX77686_CLKS_NUM];
 141         struct clk **clocks;
 142         int i, ret;
 143
 144         clocks = devm_kzalloc(&pdev->dev, sizeof(struct clk *)
 145                                         * MAX77686_CLKS_NUM, GFP_KERNEL);
 146         if (!clocks)
 147                 return -ENOMEM;
 148
 149         for (i = 0; i < MAX77686_CLKS_NUM; i++) {
 150                 max77686_clks[i] = devm_kzalloc(&pdev->dev,
 151                                         sizeof(struct max77686_clk), GFP_KERNEL);
 152                 if (!max77686_clks[i])
 153                         return -ENOMEM;
 154         }
 155
 156         for (i = 0; i < MAX77686_CLKS_NUM; i++) {
 157                 max77686_clks[i]->iodev = iodev;
 158                 max77686_clks[i]->mask = 1 << i;
 159                 max77686_clks[i]->hw.init = &max77686_clks_init[i];
 160
 161                 clocks[i] = max77686_clk_register(&pdev->dev, max77686_clks[i]);
 162                 if (IS_ERR(clocks[i])) {
 163                         ret = PTR_ERR(clocks[i]);
 164                         dev_err(&pdev->dev, "failed to register %s\n",
 165                                 max77686_clks[i]->hw.init->name);
 166                         goto err_clocks;
 167                 }
 168         }
 169
 170         platform_set_drvdata(pdev, clocks);
 171
 172         if (iodev->dev->of_node) {
 173                 struct clk_onecell_data *of_data;
 174
 175                 of_data = devm_kzalloc(&pdev->dev,
 176                                         sizeof(*of_data), GFP_KERNEL);
 177                 if (!of_data) {
 178                         ret = -ENOMEM;
 179                         goto err_clocks;
 180                 }
 181
 182                 of_data->clks = clocks;
 183                 of_data->clk_num = MAX77686_CLKS_NUM;
 184                 ret = of_clk_add_provider(iodev->dev->of_node,
 185                                         of_clk_src_onecell_get, of_data);
 186                 if (ret) {
 187                         dev_err(&pdev->dev, "failed to register OF clock provider\n");
 188                         goto err_clocks;
 189                 }
 190         }
 191
 192         return 0;
 193
 194 err_clocks:
 195         for (--i; i >= 0; --i) {
 196                 clkdev_drop(max77686_clks[i]->lookup);
 197                 clk_unregister(max77686_clks[i]->hw.clk);
 198         }
 199
 200         return ret;
 201 }
 202
 203 static int max77686_clk_remove(struct platform_device *pdev)
 204 {
 205         struct max77686_dev *iodev = dev_get_drvdata(pdev->dev.parent);
 206         struct clk **clocks = platform_get_drvdata(pdev);
 207         int i;
 208
 209         if (iodev->dev->of_node)
 210                 of_clk_del_provider(iodev->dev->of_node);
 211
 212         for (i = 0; i < MAX77686_CLKS_NUM; i++) {
 213                 struct clk_hw *hw = __clk_get_hw(clocks[i]);
 214                 struct max77686_clk *max77686 = to_max77686_clk(hw);
 215
 216                 clkdev_drop(max77686->lookup);
 217                 clk_unregister(clocks[i]);
 218         }
 219         return 0;
 220 }
 221
 222 static const struct platform_device_id max77686_clk_id[] = {
 223         { "max77686-clk", 0},
 224         { },
 225 };
 226 MODULE_DEVICE_TABLE(platform, max77686_clk_id);
 227
 228 static struct platform_driver max77686_clk_driver = {
 229         .driver = {
 230                 .name  = "max77686-clk",
 231                 .owner = THIS_MODULE,
 232         },
 233         .probe = max77686_clk_probe,
 234         .remove = max77686_clk_remove,
 235         .id_table = max77686_clk_id,
 236 };
 237
 238 static int __init max77686_clk_init(void)
 239 {
 240         return platform_driver_register(&max77686_clk_driver);
 241 }
 242 subsys_initcall(max77686_clk_init);
 243
 244 static void __init max77686_clk_cleanup(void)
 245 {
 246         platform_driver_unregister(&max77686_clk_driver);
 247 }
 248 module_exit(max77686_clk_cleanup);
 249
 250 MODULE_DESCRIPTION("MAXIM 77686 Clock Driver");
 251 MODULE_AUTHOR("Jonghwa Lee <jonghwa3.lee@samsung.com>");
 252 MODULE_LICENSE("GPL");