drivers/clk/clk-bd718x7.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2018 ROHM Semiconductors
   3
   4 #include <linux/kernel.h>
   5 #include <linux/module.h>
   6 #include <linux/init.h>
   7 #include <linux/err.h>
   8 #include <linux/platform_device.h>
   9 #include <linux/slab.h>
  10 #include <linux/mfd/rohm-bd718x7.h>
  11 #include <linux/clk-provider.h>
  12 #include <linux/clkdev.h>
  13 #include <linux/regmap.h>
  14
  15 struct bd718xx_clk {
  16         struct clk_hw hw;
  17         u8 reg;
  18         u8 mask;
  19         struct platform_device *pdev;
  20         struct bd718xx *mfd;
  21 };
  22
  23 static int bd71837_clk_set(struct clk_hw *hw, int status)
  24 {
  25         struct bd718xx_clk *c = container_of(hw, struct bd718xx_clk, hw);
  26
  27         return regmap_update_bits(c->mfd->regmap, c->reg, c->mask, status);
  28 }
  29
  30 static void bd71837_clk_disable(struct clk_hw *hw)
  31 {
  32         int rv;
  33         struct bd718xx_clk *c = container_of(hw, struct bd718xx_clk, hw);
  34
  35         rv = bd71837_clk_set(hw, 0);
  36         if (rv)
  37                 dev_dbg(&c->pdev->dev, "Failed to disable 32K clk (%d)\n", rv);
  38 }
  39
  40 static int bd71837_clk_enable(struct clk_hw *hw)
  41 {
  42         return bd71837_clk_set(hw, 1);
  43 }
  44
  45 static int bd71837_clk_is_enabled(struct clk_hw *hw)
  46 {
  47         int enabled;
  48         int rval;
  49         struct bd718xx_clk *c = container_of(hw, struct bd718xx_clk, hw);
  50
  51         rval = regmap_read(c->mfd->regmap, c->reg, &enabled);
  52
  53         if (rval)
  54                 return rval;
  55
  56         return enabled & c->mask;
  57 }
  58
  59 static const struct clk_ops bd71837_clk_ops = {
  60         .prepare = &bd71837_clk_enable,
  61         .unprepare = &bd71837_clk_disable,
  62         .is_prepared = &bd71837_clk_is_enabled,
  63 };
  64
  65 static int bd71837_clk_probe(struct platform_device *pdev)
  66 {
  67         struct bd718xx_clk *c;
  68         int rval = -ENOMEM;
  69         const char *parent_clk;
  70         struct device *parent = pdev->dev.parent;
  71         struct bd718xx *mfd = dev_get_drvdata(parent);
  72         struct clk_init_data init = {
  73                 .name = "bd718xx-32k-out",
  74                 .ops = &bd71837_clk_ops,
  75         };
  76
  77         c = devm_kzalloc(&pdev->dev, sizeof(*c), GFP_KERNEL);
  78         if (!c)
  79                 return -ENOMEM;
  80
  81         init.num_parents = 1;
  82         parent_clk = of_clk_get_parent_name(parent->of_node, 0);
  83
  84         init.parent_names = &parent_clk;
  85         if (!parent_clk) {
  86                 dev_err(&pdev->dev, "No parent clk found\n");
  87                 return -EINVAL;
  88         }
  89
  90         c->reg = BD718XX_REG_OUT32K;
  91         c->mask = BD718XX_OUT32K_EN;
  92         c->mfd = mfd;
  93         c->pdev = pdev;
  94         c->hw.init = &init;
  95
  96         of_property_read_string_index(parent->of_node,
  97                                       "clock-output-names", 0, &init.name);
  98
  99         rval = devm_clk_hw_register(&pdev->dev, &c->hw);
 100         if (rval) {
 101                 dev_err(&pdev->dev, "failed to register 32K clk");
 102                 return rval;
 103         }
 104         rval = devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get,
 105                                            &c->hw);
 106         if (rval)
 107                 dev_err(&pdev->dev, "adding clk provider failed\n");
 108
 109         return rval;
 110 }
 111
 112 static struct platform_driver bd71837_clk = {
 113         .driver = {
 114                 .name = "bd718xx-clk",
 115         },
 116         .probe = bd71837_clk_probe,
 117 };
 118
 119 module_platform_driver(bd71837_clk);
 120
 121 MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
 122 MODULE_DESCRIPTION("BD71837 chip clk driver");
 123 MODULE_LICENSE("GPL");