LXR linux/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
  20struct hi655x_clk {
  21        struct hi655x_pmic *hi655x;
  22        struct clk_hw       clk_hw;
  23};
  24
  25static unsigned long hi655x_clk_recalc_rate(struct clk_hw *hw,
  26                                            unsigned long parent_rate)
  27{
  28        return 32768;
  29}
  30
  31static 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
  42static int hi655x_clk_prepare(struct clk_hw *hw)
  43{
  44        return hi655x_clk_enable(hw, true);
  45}
  46
  47static void hi655x_clk_unprepare(struct clk_hw *hw)
  48{
  49        hi655x_clk_enable(hw, false);
  50}
  51
  52static 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
  67static 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
  74static 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
 106static struct platform_driver hi655x_clk_driver = {
 107        .probe =  hi655x_clk_probe,
 108        .driver         = {
 109                .name   = "hi655x-clk",
 110        },
 111};
 112
 113module_platform_driver(hi655x_clk_driver);
 114
 115MODULE_DESCRIPTION("Clk driver for the hi655x series PMICs");
 116MODULE_AUTHOR("Daniel Lezcano <daniel.lezcano@linaro.org>");
 117MODULE_LICENSE("GPL");
 118MODULE_ALIAS("platform:hi655x-clk");
 119