LXR linux/drivers/clk/versatile/clk-vexpress-osc.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *
   4 * Copyright (C) 2012 ARM Limited
   5 */
   6
   7#include <linux/clkdev.h>
   8#include <linux/clk-provider.h>
   9#include <linux/err.h>
  10#include <linux/module.h>
  11#include <linux/of.h>
  12#include <linux/platform_device.h>
  13#include <linux/slab.h>
  14#include <linux/vexpress.h>
  15
  16struct vexpress_osc {
  17        struct regmap *reg;
  18        struct clk_hw hw;
  19        unsigned long rate_min;
  20        unsigned long rate_max;
  21};
  22
  23#define to_vexpress_osc(osc) container_of(osc, struct vexpress_osc, hw)
  24
  25static unsigned long vexpress_osc_recalc_rate(struct clk_hw *hw,
  26                unsigned long parent_rate)
  27{
  28        struct vexpress_osc *osc = to_vexpress_osc(hw);
  29        u32 rate;
  30
  31        regmap_read(osc->reg, 0, &rate);
  32
  33        return rate;
  34}
  35
  36static long vexpress_osc_round_rate(struct clk_hw *hw, unsigned long rate,
  37                unsigned long *parent_rate)
  38{
  39        struct vexpress_osc *osc = to_vexpress_osc(hw);
  40
  41        if (osc->rate_min && rate < osc->rate_min)
  42                rate = osc->rate_min;
  43
  44        if (osc->rate_max && rate > osc->rate_max)
  45                rate = osc->rate_max;
  46
  47        return rate;
  48}
  49
  50static int vexpress_osc_set_rate(struct clk_hw *hw, unsigned long rate,
  51                unsigned long parent_rate)
  52{
  53        struct vexpress_osc *osc = to_vexpress_osc(hw);
  54
  55        return regmap_write(osc->reg, 0, rate);
  56}
  57
  58static const struct clk_ops vexpress_osc_ops = {
  59        .recalc_rate = vexpress_osc_recalc_rate,
  60        .round_rate = vexpress_osc_round_rate,
  61        .set_rate = vexpress_osc_set_rate,
  62};
  63
  64
  65static int vexpress_osc_probe(struct platform_device *pdev)
  66{
  67        struct clk_init_data init;
  68        struct vexpress_osc *osc;
  69        u32 range[2];
  70        int ret;
  71
  72        osc = devm_kzalloc(&pdev->dev, sizeof(*osc), GFP_KERNEL);
  73        if (!osc)
  74                return -ENOMEM;
  75
  76        osc->reg = devm_regmap_init_vexpress_config(&pdev->dev);
  77        if (IS_ERR(osc->reg))
  78                return PTR_ERR(osc->reg);
  79
  80        if (of_property_read_u32_array(pdev->dev.of_node, "freq-range", range,
  81                        ARRAY_SIZE(range)) == 0) {
  82                osc->rate_min = range[0];
  83                osc->rate_max = range[1];
  84        }
  85
  86        if (of_property_read_string(pdev->dev.of_node, "clock-output-names",
  87                        &init.name) != 0)
  88                init.name = dev_name(&pdev->dev);
  89
  90        init.ops = &vexpress_osc_ops;
  91        init.flags = 0;
  92        init.num_parents = 0;
  93
  94        osc->hw.init = &init;
  95
  96        ret = devm_clk_hw_register(&pdev->dev, &osc->hw);
  97        if (ret < 0)
  98                return ret;
  99
 100        devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get, &osc->hw);
 101        clk_hw_set_rate_range(&osc->hw, osc->rate_min, osc->rate_max);
 102
 103        dev_dbg(&pdev->dev, "Registered clock '%s'\n", init.name);
 104
 105        return 0;
 106}
 107
 108static const struct of_device_id vexpress_osc_of_match[] = {
 109        { .compatible = "arm,vexpress-osc", },
 110        {}
 111};
 112MODULE_DEVICE_TABLE(of, vexpress_osc_of_match);
 113
 114static struct platform_driver vexpress_osc_driver = {
 115        .driver = {
 116                .name = "vexpress-osc",
 117                .of_match_table = vexpress_osc_of_match,
 118        },
 119        .probe = vexpress_osc_probe,
 120};
 121module_platform_driver(vexpress_osc_driver);
 122MODULE_LICENSE("GPL v2");
 123