drivers/clk/clk-s2mps11.c

   1 /*
   2  * clk-s2mps11.c - Clock driver for S2MPS11.
   3  *
   4  * Copyright (C) 2013 Samsung Electornics
   5  *
   6  * This program is free software; you can redistribute  it and/or modify it
   7  * under  the terms of  the GNU General  Public License as published by the
   8  * Free Software Foundation;  either version 2 of the  License, or (at your
   9  * option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/err.h>
  24 #include <linux/of.h>
  25 #include <linux/clkdev.h>
  26 #include <linux/regmap.h>
  27 #include <linux/clk-provider.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/mfd/samsung/s2mps11.h>
  30 #include <linux/mfd/samsung/core.h>
  31
  32 #define s2mps11_name(a) (a->hw.init->name)
  33
  34 static struct clk **clk_table;
  35 static struct clk_onecell_data clk_data;
  36
  37 enum {
  38         S2MPS11_CLK_AP = 0,
  39         S2MPS11_CLK_CP,
  40         S2MPS11_CLK_BT,
  41         S2MPS11_CLKS_NUM,
  42 };
  43
  44 struct s2mps11_clk {
  45         struct sec_pmic_dev *iodev;
  46         struct clk_hw hw;
  47         struct clk *clk;
  48         struct clk_lookup *lookup;
  49         u32 mask;
  50         bool enabled;
  51 };
  52
  53 static struct s2mps11_clk *to_s2mps11_clk(struct clk_hw *hw)
  54 {
  55         return container_of(hw, struct s2mps11_clk, hw);
  56 }
  57
  58 static int s2mps11_clk_prepare(struct clk_hw *hw)
  59 {
  60         struct s2mps11_clk *s2mps11 = to_s2mps11_clk(hw);
  61         int ret;
  62
  63         ret = regmap_update_bits(s2mps11->iodev->regmap,
  64                                 S2MPS11_REG_RTC_CTRL,
  65                                  s2mps11->mask, s2mps11->mask);
  66         if (!ret)
  67                 s2mps11->enabled = true;
  68
  69         return ret;
  70 }
  71
  72 static void s2mps11_clk_unprepare(struct clk_hw *hw)
  73 {
  74         struct s2mps11_clk *s2mps11 = to_s2mps11_clk(hw);
  75         int ret;
  76
  77         ret = regmap_update_bits(s2mps11->iodev->regmap, S2MPS11_REG_RTC_CTRL,
  78                            s2mps11->mask, ~s2mps11->mask);
  79
  80         if (!ret)
  81                 s2mps11->enabled = false;
  82 }
  83
  84 static int s2mps11_clk_is_enabled(struct clk_hw *hw)
  85 {
  86         struct s2mps11_clk *s2mps11 = to_s2mps11_clk(hw);
  87
  88         return s2mps11->enabled;
  89 }
  90
  91 static unsigned long s2mps11_clk_recalc_rate(struct clk_hw *hw,
  92                                              unsigned long parent_rate)
  93 {
  94         struct s2mps11_clk *s2mps11 = to_s2mps11_clk(hw);
  95         if (s2mps11->enabled)
  96                 return 32768;
  97         else
  98                 return 0;
  99 }
 100
 101 static struct clk_ops s2mps11_clk_ops = {
 102         .prepare        = s2mps11_clk_prepare,
 103         .unprepare      = s2mps11_clk_unprepare,
 104         .is_enabled     = s2mps11_clk_is_enabled,
 105         .recalc_rate    = s2mps11_clk_recalc_rate,
 106 };
 107
 108 static struct clk_init_data s2mps11_clks_init[S2MPS11_CLKS_NUM] = {
 109         [S2MPS11_CLK_AP] = {
 110                 .name = "s2mps11_ap",
 111                 .ops = &s2mps11_clk_ops,
 112                 .flags = CLK_IS_ROOT,
 113         },
 114         [S2MPS11_CLK_CP] = {
 115                 .name = "s2mps11_cp",
 116                 .ops = &s2mps11_clk_ops,
 117                 .flags = CLK_IS_ROOT,
 118         },
 119         [S2MPS11_CLK_BT] = {
 120                 .name = "s2mps11_bt",
 121                 .ops = &s2mps11_clk_ops,
 122                 .flags = CLK_IS_ROOT,
 123         },
 124 };
 125
 126 static struct device_node *s2mps11_clk_parse_dt(struct platform_device *pdev)
 127 {
 128         struct sec_pmic_dev *iodev = dev_get_drvdata(pdev->dev.parent);
 129         struct device_node *clk_np;
 130         int i;
 131
 132         if (!iodev->dev->of_node)
 133                 return NULL;
 134
 135         clk_np = of_find_node_by_name(iodev->dev->of_node, "clocks");
 136         if (!clk_np) {
 137                 dev_err(&pdev->dev, "could not find clock sub-node\n");
 138                 return ERR_PTR(-EINVAL);
 139         }
 140
 141         clk_table = devm_kzalloc(&pdev->dev, sizeof(struct clk *) *
 142                                  S2MPS11_CLKS_NUM, GFP_KERNEL);
 143         if (!clk_table)
 144                 return ERR_PTR(-ENOMEM);
 145
 146         for (i = 0; i < S2MPS11_CLKS_NUM; i++)
 147                 of_property_read_string_index(clk_np, "clock-output-names", i,
 148                                 &s2mps11_clks_init[i].name);
 149
 150         return clk_np;
 151 }
 152
 153 static int s2mps11_clk_probe(struct platform_device *pdev)
 154 {
 155         struct sec_pmic_dev *iodev = dev_get_drvdata(pdev->dev.parent);
 156         struct s2mps11_clk *s2mps11_clks, *s2mps11_clk;
 157         struct device_node *clk_np = NULL;
 158         int i, ret = 0;
 159         u32 val;
 160
 161         s2mps11_clks = devm_kzalloc(&pdev->dev, sizeof(*s2mps11_clk) *
 162                                         S2MPS11_CLKS_NUM, GFP_KERNEL);
 163         if (!s2mps11_clks)
 164                 return -ENOMEM;
 165
 166         s2mps11_clk = s2mps11_clks;
 167
 168         clk_np = s2mps11_clk_parse_dt(pdev);
 169         if (IS_ERR(clk_np))
 170                 return PTR_ERR(clk_np);
 171
 172         for (i = 0; i < S2MPS11_CLKS_NUM; i++, s2mps11_clk++) {
 173                 s2mps11_clk->iodev = iodev;
 174                 s2mps11_clk->hw.init = &s2mps11_clks_init[i];
 175                 s2mps11_clk->mask = 1 << i;
 176
 177                 ret = regmap_read(s2mps11_clk->iodev->regmap,
 178                                   S2MPS11_REG_RTC_CTRL, &val);
 179                 if (ret < 0)
 180                         goto err_reg;
 181
 182                 s2mps11_clk->enabled = val & s2mps11_clk->mask;
 183
 184                 s2mps11_clk->clk = devm_clk_register(&pdev->dev,
 185                                                         &s2mps11_clk->hw);
 186                 if (IS_ERR(s2mps11_clk->clk)) {
 187                         dev_err(&pdev->dev, "Fail to register : %s\n",
 188                                                 s2mps11_name(s2mps11_clk));
 189                         ret = PTR_ERR(s2mps11_clk->clk);
 190                         goto err_reg;
 191                 }
 192
 193                 s2mps11_clk->lookup = devm_kzalloc(&pdev->dev,
 194                                         sizeof(struct clk_lookup), GFP_KERNEL);
 195                 if (!s2mps11_clk->lookup) {
 196                         ret = -ENOMEM;
 197                         goto err_lup;
 198                 }
 199
 200                 s2mps11_clk->lookup->con_id = s2mps11_name(s2mps11_clk);
 201                 s2mps11_clk->lookup->clk = s2mps11_clk->clk;
 202
 203                 clkdev_add(s2mps11_clk->lookup);
 204         }
 205
 206         if (clk_table) {
 207                 for (i = 0; i < S2MPS11_CLKS_NUM; i++)
 208                         clk_table[i] = s2mps11_clks[i].clk;
 209
 210                 clk_data.clks = clk_table;
 211                 clk_data.clk_num = S2MPS11_CLKS_NUM;
 212                 of_clk_add_provider(clk_np, of_clk_src_onecell_get, &clk_data);
 213         }
 214
 215         platform_set_drvdata(pdev, s2mps11_clks);
 216
 217         return ret;
 218 err_lup:
 219         devm_clk_unregister(&pdev->dev, s2mps11_clk->clk);
 220 err_reg:
 221         while (s2mps11_clk > s2mps11_clks) {
 222                 if (s2mps11_clk->lookup) {
 223                         clkdev_drop(s2mps11_clk->lookup);
 224                         devm_clk_unregister(&pdev->dev, s2mps11_clk->clk);
 225                 }
 226                 s2mps11_clk--;
 227         }
 228
 229         return ret;
 230 }
 231
 232 static int s2mps11_clk_remove(struct platform_device *pdev)
 233 {
 234         struct s2mps11_clk *s2mps11_clks = platform_get_drvdata(pdev);
 235         int i;
 236
 237         for (i = 0; i < S2MPS11_CLKS_NUM; i++)
 238                 clkdev_drop(s2mps11_clks[i].lookup);
 239
 240         return 0;
 241 }
 242
 243 static const struct platform_device_id s2mps11_clk_id[] = {
 244         { "s2mps11-clk", 0},
 245         { },
 246 };
 247 MODULE_DEVICE_TABLE(platform, s2mps11_clk_id);
 248
 249 static struct platform_driver s2mps11_clk_driver = {
 250         .driver = {
 251                 .name  = "s2mps11-clk",
 252                 .owner = THIS_MODULE,
 253         },
 254         .probe = s2mps11_clk_probe,
 255         .remove = s2mps11_clk_remove,
 256         .id_table = s2mps11_clk_id,
 257 };
 258
 259 static int __init s2mps11_clk_init(void)
 260 {
 261         return platform_driver_register(&s2mps11_clk_driver);
 262 }
 263 subsys_initcall(s2mps11_clk_init);
 264
 265 static void __init s2mps11_clk_cleanup(void)
 266 {
 267         platform_driver_unregister(&s2mps11_clk_driver);
 268 }
 269 module_exit(s2mps11_clk_cleanup);
 270
 271 MODULE_DESCRIPTION("S2MPS11 Clock Driver");
 272 MODULE_AUTHOR("Yadwinder Singh Brar <yadi.brar@samsung.com>");
 273 MODULE_LICENSE("GPL");