drivers/clk/clk-hi655x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Clock driver for Hi655x
   4  *
   5  * Copyright (c) 2017, Linaro Ltd.
   6  *
   7  * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
   8  */
   9 #include <linux/clk-provider.h>
  10 #include <linux/module.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/regmap.h>
  13 #include <linux/slab.h>
  14 #include <linux/mfd/core.h>
  15 #include <linux/mfd/hi655x-pmic.h>
  16
  17 #define HI655X_CLK_BASE HI655X_BUS_ADDR(0x1c)
  18 #define HI655X_CLK_SET  BIT(6)
  19
  20 struct hi655x_clk {
  21         struct hi655x_pmic *hi655x;
  22         struct clk_hw       clk_hw;
  23 };
  24
  25 static unsigned long hi655x_clk_recalc_rate(struct clk_hw *hw,
  26                                             unsigned long parent_rate)
  27 {
  28         return 32768;
  29 }
  30
  31 static int hi655x_clk_enable(struct clk_hw *hw, bool enable)
  32 {
  33         struct hi655x_clk *hi655x_clk =
  34                 container_of(hw, struct hi655x_clk, clk_hw);
  35
  36         struct hi655x_pmic *hi655x = hi655x_clk->hi655x;
  37
  38         return regmap_update_bits(hi655x->regmap, HI655X_CLK_BASE,
  39                                   HI655X_CLK_SET, enable ? HI655X_CLK_SET : 0);
  40 }
  41
  42 static int hi655x_clk_prepare(struct clk_hw *hw)
  43 {
  44         return hi655x_clk_enable(hw, true);
  45 }
  46
  47 static void hi655x_clk_unprepare(struct clk_hw *hw)
  48 {
  49         hi655x_clk_enable(hw, false);
  50 }
  51
  52 static int hi655x_clk_is_prepared(struct clk_hw *hw)
  53 {
  54         struct hi655x_clk *hi655x_clk =
  55                 container_of(hw, struct hi655x_clk, clk_hw);
  56         struct hi655x_pmic *hi655x = hi655x_clk->hi655x;
  57         int ret;
  58         uint32_t val;
  59
  60         ret = regmap_read(hi655x->regmap, HI655X_CLK_BASE, &val);
  61         if (ret < 0)
  62                 return ret;
  63
  64         return val & HI655X_CLK_BASE;
  65 }
  66
  67 static const struct clk_ops hi655x_clk_ops = {
  68         .prepare     = hi655x_clk_prepare,
  69         .unprepare   = hi655x_clk_unprepare,
  70         .is_prepared = hi655x_clk_is_prepared,
  71         .recalc_rate = hi655x_clk_recalc_rate,
  72 };
  73
  74 static int hi655x_clk_probe(struct platform_device *pdev)
  75 {
  76         struct device *parent = pdev->dev.parent;
  77         struct hi655x_pmic *hi655x = dev_get_drvdata(parent);
  78         struct hi655x_clk *hi655x_clk;
  79         const char *clk_name = "hi655x-clk";
  80         struct clk_init_data init = {
  81                 .name = clk_name,
  82                 .ops = &hi655x_clk_ops
  83         };
  84         int ret;
  85
  86         hi655x_clk = devm_kzalloc(&pdev->dev, sizeof(*hi655x_clk), GFP_KERNEL);
  87         if (!hi655x_clk)
  88                 return -ENOMEM;
  89
  90         of_property_read_string_index(parent->of_node, "clock-output-names",
  91                                       0, &clk_name);
  92
  93         hi655x_clk->clk_hw.init = &init;
  94         hi655x_clk->hi655x      = hi655x;
  95
  96         platform_set_drvdata(pdev, hi655x_clk);
  97
  98         ret = devm_clk_hw_register(&pdev->dev, &hi655x_clk->clk_hw);
  99         if (ret)
 100                 return ret;
 101
 102         return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get,
 103                                            &hi655x_clk->clk_hw);
 104 }
 105
 106 static struct platform_driver hi655x_clk_driver = {
 107         .probe =  hi655x_clk_probe,
 108         .driver         = {
 109                 .name   = "hi655x-clk",
 110         },
 111 };
 112
 113 module_platform_driver(hi655x_clk_driver);
 114
 115 MODULE_DESCRIPTION("Clk driver for the hi655x series PMICs");
 116 MODULE_AUTHOR("Daniel Lezcano <daniel.lezcano@linaro.org>");
 117 MODULE_LICENSE("GPL");
 118 MODULE_ALIAS("platform:hi655x-clk");