kernel/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.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
  28 struct 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
  35 static unsigned long rk808_clkout_recalc_rate(struct clk_hw *hw,
  36                                               unsigned long parent_rate)
  37 {
  38         return 32768;
  39 }
  40
  41 static 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
  52 static int rk808_clkout2_prepare(struct clk_hw *hw)
  53 {
  54         return rk808_clkout2_enable(hw, true);
  55 }
  56
  57 static void rk808_clkout2_unprepare(struct clk_hw *hw)
  58 {
  59         rk808_clkout2_enable(hw, false);
  60 }
  61
  62 static 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
  78 static const struct clk_ops rk808_clkout1_ops = {
  79         .recalc_rate = rk808_clkout_recalc_rate,
  80 };
  81
  82 static 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
  89 static 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
 146 static 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
 157 static 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
 165 module_platform_driver(rk808_clkout_driver);
 166
 167 MODULE_DESCRIPTION("Clkout driver for the rk808 series PMICs");
 168 MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
 169 MODULE_LICENSE("GPL");
 170 MODULE_ALIAS("platform:rk808-clkout");