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 *get_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;
  55         int ret;
  56
  57         max77686 = get_max77686_clk(hw);
  58         if (!max77686)
  59                 return -ENOMEM;
  60
  61         ret = regmap_update_bits(max77686->iodev->regmap,
  62                 MAX77686_REG_32KHZ, max77686->mask, max77686->mask);
  63
  64         return ret;
  65 }
  66
  67 static void max77686_clk_unprepare(struct clk_hw *hw)
  68 {
  69         struct max77686_clk *max77686;
  70
  71         max77686 = get_max77686_clk(hw);
  72         if (!max77686)
  73                 return;
  74
  75         regmap_update_bits(max77686->iodev->regmap,
  76                 MAX77686_REG_32KHZ, max77686->mask, ~max77686->mask);
  77 }
  78
  79 static int max77686_clk_is_enabled(struct clk_hw *hw)
  80 {
  81         struct max77686_clk *max77686;
  82         int ret;
  83         u32 val;
  84
  85         max77686 = get_max77686_clk(hw);
  86         if (!max77686)
  87                 return -ENOMEM;
  88
  89         ret = regmap_read(max77686->iodev->regmap,
  90                                 MAX77686_REG_32KHZ, &val);
  91
  92         if (ret < 0)
  93                 return -EINVAL;
  94
  95         return val & max77686->mask;
  96 }
  97
  98 static struct clk_ops max77686_clk_ops = {
  99         .prepare        = max77686_clk_prepare,
 100         .unprepare      = max77686_clk_unprepare,
 101         .is_enabled     = max77686_clk_is_enabled,
 102 };
 103
 104 static struct clk_init_data max77686_clks_init[MAX77686_CLKS_NUM] = {
 105         [MAX77686_CLK_AP] = {
 106                 .name = "32khz_ap",
 107                 .ops = &max77686_clk_ops,
 108                 .flags = CLK_IS_ROOT,
 109         },
 110         [MAX77686_CLK_CP] = {
 111                 .name = "32khz_cp",
 112                 .ops = &max77686_clk_ops,
 113                 .flags = CLK_IS_ROOT,
 114         },
 115         [MAX77686_CLK_PMIC] = {
 116                 .name = "32khz_pmic",
 117                 .ops = &max77686_clk_ops,
 118                 .flags = CLK_IS_ROOT,
 119         },
 120 };
 121
 122 static int max77686_clk_register(struct device *dev,
 123                                 struct max77686_clk *max77686)
 124 {
 125         struct clk *clk;
 126         struct clk_hw *hw = &max77686->hw;
 127
 128         clk = clk_register(dev, hw);
 129
 130         if (IS_ERR(clk))
 131                 return -ENOMEM;
 132
 133         max77686->lookup = devm_kzalloc(dev, sizeof(struct clk_lookup),
 134                                         GFP_KERNEL);
 135         if (IS_ERR(max77686->lookup))
 136                 return -ENOMEM;
 137
 138         max77686->lookup->con_id = hw->init->name;
 139         max77686->lookup->clk = clk;
 140
 141         clkdev_add(max77686->lookup);
 142
 143         return 0;
 144 }
 145
 146 static int max77686_clk_probe(struct platform_device *pdev)
 147 {
 148         struct max77686_dev *iodev = dev_get_drvdata(pdev->dev.parent);
 149         struct max77686_clk **max77686_clks;
 150         int i, ret;
 151
 152         max77686_clks = devm_kzalloc(&pdev->dev, sizeof(struct max77686_clk *)
 153                                         * MAX77686_CLKS_NUM, GFP_KERNEL);
 154         if (IS_ERR(max77686_clks))
 155                 return -ENOMEM;
 156
 157         for (i = 0; i < MAX77686_CLKS_NUM; i++) {
 158                 max77686_clks[i] = devm_kzalloc(&pdev->dev,
 159                                         sizeof(struct max77686_clk), GFP_KERNEL);
 160                 if (IS_ERR(max77686_clks[i]))
 161                         return -ENOMEM;
 162         }
 163
 164         for (i = 0; i < MAX77686_CLKS_NUM; i++) {
 165                 max77686_clks[i]->iodev = iodev;
 166                 max77686_clks[i]->mask = 1 << i;
 167                 max77686_clks[i]->hw.init = &max77686_clks_init[i];
 168
 169                 ret = max77686_clk_register(&pdev->dev, max77686_clks[i]);
 170                 if (ret) {
 171                         switch (i) {
 172                         case MAX77686_CLK_AP:
 173                                 dev_err(&pdev->dev, "Fail to register CLK_AP\n");
 174                                 goto err_clk_ap;
 175                                 break;
 176                         case MAX77686_CLK_CP:
 177                                 dev_err(&pdev->dev, "Fail to register CLK_CP\n");
 178                                 goto err_clk_cp;
 179                                 break;
 180                         case MAX77686_CLK_PMIC:
 181                                 dev_err(&pdev->dev, "Fail to register CLK_PMIC\n");
 182                                 goto err_clk_pmic;
 183                         }
 184                 }
 185         }
 186
 187         platform_set_drvdata(pdev, max77686_clks);
 188
 189         goto out;
 190
 191 err_clk_pmic:
 192         clkdev_drop(max77686_clks[MAX77686_CLK_CP]->lookup);
 193         kfree(max77686_clks[MAX77686_CLK_CP]->hw.clk);
 194 err_clk_cp:
 195         clkdev_drop(max77686_clks[MAX77686_CLK_AP]->lookup);
 196         kfree(max77686_clks[MAX77686_CLK_AP]->hw.clk);
 197 err_clk_ap:
 198 out:
 199         return ret;
 200 }
 201
 202 static int max77686_clk_remove(struct platform_device *pdev)
 203 {
 204         struct max77686_clk **max77686_clks = platform_get_drvdata(pdev);
 205         int i;
 206
 207         for (i = 0; i < MAX77686_CLKS_NUM; i++) {
 208                 clkdev_drop(max77686_clks[i]->lookup);
 209                 kfree(max77686_clks[i]->hw.clk);
 210         }
 211         return 0;
 212 }
 213
 214 static const struct platform_device_id max77686_clk_id[] = {
 215         { "max77686-clk", 0},
 216         { },
 217 };
 218 MODULE_DEVICE_TABLE(platform, max77686_clk_id);
 219
 220 static struct platform_driver max77686_clk_driver = {
 221         .driver = {
 222                 .name  = "max77686-clk",
 223                 .owner = THIS_MODULE,
 224         },
 225         .probe = max77686_clk_probe,
 226         .remove = max77686_clk_remove,
 227         .id_table = max77686_clk_id,
 228 };
 229
 230 static int __init max77686_clk_init(void)
 231 {
 232         return platform_driver_register(&max77686_clk_driver);
 233 }
 234 subsys_initcall(max77686_clk_init);
 235
 236 static void __init max77686_clk_cleanup(void)
 237 {
 238         platform_driver_unregister(&max77686_clk_driver);
 239 }
 240 module_exit(max77686_clk_cleanup);
 241
 242 MODULE_DESCRIPTION("MAXIM 77686 Clock Driver");
 243 MODULE_AUTHOR("Jonghwa Lee <jonghwa3.lee@samsung.com>");
 244 MODULE_LICENSE("GPL");