linux/drivers/clk/clk-max77686.c
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   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
  33enum {
  34        MAX77686_CLK_AP = 0,
  35        MAX77686_CLK_CP,
  36        MAX77686_CLK_PMIC,
  37        MAX77686_CLKS_NUM,
  38};
  39
  40struct max77686_clk {
  41        struct max77686_dev *iodev;
  42        u32 mask;
  43        struct clk_hw hw;
  44        struct clk_lookup *lookup;
  45};
  46
  47static struct max77686_clk *get_max77686_clk(struct clk_hw *hw)
  48{
  49        return container_of(hw, struct max77686_clk, hw);
  50}
  51
  52static 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
  67static 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
  79static 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
  98static 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
 104static 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
 122static 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
 146static 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
 191err_clk_pmic:
 192        clkdev_drop(max77686_clks[MAX77686_CLK_CP]->lookup);
 193        kfree(max77686_clks[MAX77686_CLK_CP]->hw.clk);
 194err_clk_cp:
 195        clkdev_drop(max77686_clks[MAX77686_CLK_AP]->lookup);
 196        kfree(max77686_clks[MAX77686_CLK_AP]->hw.clk);
 197err_clk_ap:
 198out:
 199        return ret;
 200}
 201
 202static 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
 214static const struct platform_device_id max77686_clk_id[] = {
 215        { "max77686-clk", 0},
 216        { },
 217};
 218MODULE_DEVICE_TABLE(platform, max77686_clk_id);
 219
 220static 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
 230static int __init max77686_clk_init(void)
 231{
 232        return platform_driver_register(&max77686_clk_driver);
 233}
 234subsys_initcall(max77686_clk_init);
 235
 236static void __init max77686_clk_cleanup(void)
 237{
 238        platform_driver_unregister(&max77686_clk_driver);
 239}
 240module_exit(max77686_clk_cleanup);
 241
 242MODULE_DESCRIPTION("MAXIM 77686 Clock Driver");
 243MODULE_AUTHOR("Jonghwa Lee <jonghwa3.lee@samsung.com>");
 244MODULE_LICENSE("GPL");
 245
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