linux/drivers/clk/clk-rk808.c
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   1/*
   2 * Clkout driver for Rockchip RK808
   3 *
   4 * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
   5 *
   6 * Author:Chris Zhong <zyw@rock-chips.com>
   7 *
   8 * This program is free software; you can redistribute it and/or modify it
   9 * under the terms and conditions of the GNU General Public License,
  10 * version 2, as published by the Free Software Foundation.
  11 *
  12 * This program is distributed in the hope it will be useful, but WITHOUT
  13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15 * more details.
  16 */
  17
  18#include <linux/clk.h>
  19#include <linux/clk-provider.h>
  20#include <linux/module.h>
  21#include <linux/slab.h>
  22#include <linux/platform_device.h>
  23#include <linux/mfd/rk808.h>
  24#include <linux/i2c.h>
  25
  26#define RK808_NR_OUTPUT 2
  27
  28struct rk808_clkout {
  29        struct rk808 *rk808;
  30        struct clk_onecell_data clk_data;
  31        struct clk_hw           clkout1_hw;
  32        struct clk_hw           clkout2_hw;
  33};
  34
  35static unsigned long rk808_clkout_recalc_rate(struct clk_hw *hw,
  36                                              unsigned long parent_rate)
  37{
  38        return 32768;
  39}
  40
  41static int rk808_clkout2_enable(struct clk_hw *hw, bool enable)
  42{
  43        struct rk808_clkout *rk808_clkout = container_of(hw,
  44                                                         struct rk808_clkout,
  45                                                         clkout2_hw);
  46        struct rk808 *rk808 = rk808_clkout->rk808;
  47
  48        return regmap_update_bits(rk808->regmap, RK808_CLK32OUT_REG,
  49                                  CLK32KOUT2_EN, enable ? CLK32KOUT2_EN : 0);
  50}
  51
  52static int rk808_clkout2_prepare(struct clk_hw *hw)
  53{
  54        return rk808_clkout2_enable(hw, true);
  55}
  56
  57static void rk808_clkout2_unprepare(struct clk_hw *hw)
  58{
  59        rk808_clkout2_enable(hw, false);
  60}
  61
  62static int rk808_clkout2_is_prepared(struct clk_hw *hw)
  63{
  64        struct rk808_clkout *rk808_clkout = container_of(hw,
  65                                                         struct rk808_clkout,
  66                                                         clkout2_hw);
  67        struct rk808 *rk808 = rk808_clkout->rk808;
  68        uint32_t val;
  69
  70        int ret = regmap_read(rk808->regmap, RK808_CLK32OUT_REG, &val);
  71
  72        if (ret < 0)
  73                return ret;
  74
  75        return (val & CLK32KOUT2_EN) ? 1 : 0;
  76}
  77
  78static const struct clk_ops rk808_clkout1_ops = {
  79        .recalc_rate = rk808_clkout_recalc_rate,
  80};
  81
  82static const struct clk_ops rk808_clkout2_ops = {
  83        .prepare = rk808_clkout2_prepare,
  84        .unprepare = rk808_clkout2_unprepare,
  85        .is_prepared = rk808_clkout2_is_prepared,
  86        .recalc_rate = rk808_clkout_recalc_rate,
  87};
  88
  89static int rk808_clkout_probe(struct platform_device *pdev)
  90{
  91        struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
  92        struct i2c_client *client = rk808->i2c;
  93        struct device_node *node = client->dev.of_node;
  94        struct clk_init_data init = {};
  95        struct clk **clk_table;
  96        struct rk808_clkout *rk808_clkout;
  97
  98        rk808_clkout = devm_kzalloc(&client->dev,
  99                                    sizeof(*rk808_clkout), GFP_KERNEL);
 100        if (!rk808_clkout)
 101                return -ENOMEM;
 102
 103        rk808_clkout->rk808 = rk808;
 104
 105        clk_table = devm_kcalloc(&client->dev, RK808_NR_OUTPUT,
 106                                 sizeof(struct clk *), GFP_KERNEL);
 107        if (!clk_table)
 108                return -ENOMEM;
 109
 110        init.flags = CLK_IS_ROOT;
 111        init.parent_names = NULL;
 112        init.num_parents = 0;
 113        init.name = "rk808-clkout1";
 114        init.ops = &rk808_clkout1_ops;
 115        rk808_clkout->clkout1_hw.init = &init;
 116
 117        /* optional override of the clockname */
 118        of_property_read_string_index(node, "clock-output-names",
 119                                      0, &init.name);
 120
 121        clk_table[0] = devm_clk_register(&client->dev,
 122                                         &rk808_clkout->clkout1_hw);
 123        if (IS_ERR(clk_table[0]))
 124                return PTR_ERR(clk_table[0]);
 125
 126        init.name = "rk808-clkout2";
 127        init.ops = &rk808_clkout2_ops;
 128        rk808_clkout->clkout2_hw.init = &init;
 129
 130        /* optional override of the clockname */
 131        of_property_read_string_index(node, "clock-output-names",
 132                                      1, &init.name);
 133
 134        clk_table[1] = devm_clk_register(&client->dev,
 135                                         &rk808_clkout->clkout2_hw);
 136        if (IS_ERR(clk_table[1]))
 137                return PTR_ERR(clk_table[1]);
 138
 139        rk808_clkout->clk_data.clks = clk_table;
 140        rk808_clkout->clk_data.clk_num = RK808_NR_OUTPUT;
 141
 142        return of_clk_add_provider(node, of_clk_src_onecell_get,
 143                                   &rk808_clkout->clk_data);
 144}
 145
 146static int rk808_clkout_remove(struct platform_device *pdev)
 147{
 148        struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
 149        struct i2c_client *client = rk808->i2c;
 150        struct device_node *node = client->dev.of_node;
 151
 152        of_clk_del_provider(node);
 153
 154        return 0;
 155}
 156
 157static struct platform_driver rk808_clkout_driver = {
 158        .probe = rk808_clkout_probe,
 159        .remove = rk808_clkout_remove,
 160        .driver         = {
 161                .name   = "rk808-clkout",
 162        },
 163};
 164
 165module_platform_driver(rk808_clkout_driver);
 166
 167MODULE_DESCRIPTION("Clkout driver for the rk808 series PMICs");
 168MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
 169MODULE_LICENSE("GPL");
 170MODULE_ALIAS("platform:rk808-clkout");
 171