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