LXR linux/drivers/clk/clk-rk808.c

   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-provider.h>
  19#include <linux/module.h>
  20#include <linux/slab.h>
  21#include <linux/platform_device.h>
  22#include <linux/mfd/rk808.h>
  23#include <linux/i2c.h>
  24
  25struct rk808_clkout {
  26        struct rk808 *rk808;
  27        struct clk_hw           clkout1_hw;
  28        struct clk_hw           clkout2_hw;
  29};
  30
  31static unsigned long rk808_clkout_recalc_rate(struct clk_hw *hw,
  32                                              unsigned long parent_rate)
  33{
  34        return 32768;
  35}
  36
  37static int rk808_clkout2_enable(struct clk_hw *hw, bool enable)
  38{
  39        struct rk808_clkout *rk808_clkout = container_of(hw,
  40                                                         struct rk808_clkout,
  41                                                         clkout2_hw);
  42        struct rk808 *rk808 = rk808_clkout->rk808;
  43
  44        return regmap_update_bits(rk808->regmap, RK808_CLK32OUT_REG,
  45                                  CLK32KOUT2_EN, enable ? CLK32KOUT2_EN : 0);
  46}
  47
  48static int rk808_clkout2_prepare(struct clk_hw *hw)
  49{
  50        return rk808_clkout2_enable(hw, true);
  51}
  52
  53static void rk808_clkout2_unprepare(struct clk_hw *hw)
  54{
  55        rk808_clkout2_enable(hw, false);
  56}
  57
  58static int rk808_clkout2_is_prepared(struct clk_hw *hw)
  59{
  60        struct rk808_clkout *rk808_clkout = container_of(hw,
  61                                                         struct rk808_clkout,
  62                                                         clkout2_hw);
  63        struct rk808 *rk808 = rk808_clkout->rk808;
  64        uint32_t val;
  65
  66        int ret = regmap_read(rk808->regmap, RK808_CLK32OUT_REG, &val);
  67
  68        if (ret < 0)
  69                return ret;
  70
  71        return (val & CLK32KOUT2_EN) ? 1 : 0;
  72}
  73
  74static const struct clk_ops rk808_clkout1_ops = {
  75        .recalc_rate = rk808_clkout_recalc_rate,
  76};
  77
  78static const struct clk_ops rk808_clkout2_ops = {
  79        .prepare = rk808_clkout2_prepare,
  80        .unprepare = rk808_clkout2_unprepare,
  81        .is_prepared = rk808_clkout2_is_prepared,
  82        .recalc_rate = rk808_clkout_recalc_rate,
  83};
  84
  85static struct clk_hw *
  86of_clk_rk808_get(struct of_phandle_args *clkspec, void *data)
  87{
  88        struct rk808_clkout *rk808_clkout = data;
  89        unsigned int idx = clkspec->args[0];
  90
  91        if (idx >= 2) {
  92                pr_err("%s: invalid index %u\n", __func__, idx);
  93                return ERR_PTR(-EINVAL);
  94        }
  95
  96        return idx ? &rk808_clkout->clkout2_hw : &rk808_clkout->clkout1_hw;
  97}
  98
  99static int rk808_clkout_probe(struct platform_device *pdev)
 100{
 101        struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
 102        struct i2c_client *client = rk808->i2c;
 103        struct device_node *node = client->dev.of_node;
 104        struct clk_init_data init = {};
 105        struct rk808_clkout *rk808_clkout;
 106        int ret;
 107
 108        rk808_clkout = devm_kzalloc(&client->dev,
 109                                    sizeof(*rk808_clkout), GFP_KERNEL);
 110        if (!rk808_clkout)
 111                return -ENOMEM;
 112
 113        rk808_clkout->rk808 = rk808;
 114
 115        init.parent_names = NULL;
 116        init.num_parents = 0;
 117        init.name = "rk808-clkout1";
 118        init.ops = &rk808_clkout1_ops;
 119        rk808_clkout->clkout1_hw.init = &init;
 120
 121        /* optional override of the clockname */
 122        of_property_read_string_index(node, "clock-output-names",
 123                                      0, &init.name);
 124
 125        ret = devm_clk_hw_register(&client->dev, &rk808_clkout->clkout1_hw);
 126        if (ret)
 127                return ret;
 128
 129        init.name = "rk808-clkout2";
 130        init.ops = &rk808_clkout2_ops;
 131        rk808_clkout->clkout2_hw.init = &init;
 132
 133        /* optional override of the clockname */
 134        of_property_read_string_index(node, "clock-output-names",
 135                                      1, &init.name);
 136
 137        ret = devm_clk_hw_register(&client->dev, &rk808_clkout->clkout2_hw);
 138        if (ret)
 139                return ret;
 140
 141        return of_clk_add_hw_provider(node, of_clk_rk808_get, rk808_clkout);
 142}
 143
 144static int rk808_clkout_remove(struct platform_device *pdev)
 145{
 146        struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
 147        struct i2c_client *client = rk808->i2c;
 148        struct device_node *node = client->dev.of_node;
 149
 150        of_clk_del_provider(node);
 151
 152        return 0;
 153}
 154
 155static struct platform_driver rk808_clkout_driver = {
 156        .probe = rk808_clkout_probe,
 157        .remove = rk808_clkout_remove,
 158        .driver         = {
 159                .name   = "rk808-clkout",
 160        },
 161};
 162
 163module_platform_driver(rk808_clkout_driver);
 164
 165MODULE_DESCRIPTION("Clkout driver for the rk808 series PMICs");
 166MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
 167MODULE_LICENSE("GPL");
 168MODULE_ALIAS("platform:rk808-clkout");
 169