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
  25 #define RK808_NR_OUTPUT 2
  26
  27 struct rk808_clkout {
  28         struct rk808 *rk808;
  29         struct clk_onecell_data clk_data;
  30         struct clk_hw           clkout1_hw;
  31         struct clk_hw           clkout2_hw;
  32 };
  33
  34 static unsigned long rk808_clkout_recalc_rate(struct clk_hw *hw,
  35                                               unsigned long parent_rate)
  36 {
  37         return 32768;
  38 }
  39
  40 static int rk808_clkout2_enable(struct clk_hw *hw, bool enable)
  41 {
  42         struct rk808_clkout *rk808_clkout = container_of(hw,
  43                                                          struct rk808_clkout,
  44                                                          clkout2_hw);
  45         struct rk808 *rk808 = rk808_clkout->rk808;
  46
  47         return regmap_update_bits(rk808->regmap, RK808_CLK32OUT_REG,
  48                                   CLK32KOUT2_EN, enable ? CLK32KOUT2_EN : 0);
  49 }
  50
  51 static int rk808_clkout2_prepare(struct clk_hw *hw)
  52 {
  53         return rk808_clkout2_enable(hw, true);
  54 }
  55
  56 static void rk808_clkout2_unprepare(struct clk_hw *hw)
  57 {
  58         rk808_clkout2_enable(hw, false);
  59 }
  60
  61 static int rk808_clkout2_is_prepared(struct clk_hw *hw)
  62 {
  63         struct rk808_clkout *rk808_clkout = container_of(hw,
  64                                                          struct rk808_clkout,
  65                                                          clkout2_hw);
  66         struct rk808 *rk808 = rk808_clkout->rk808;
  67         uint32_t val;
  68
  69         int ret = regmap_read(rk808->regmap, RK808_CLK32OUT_REG, &val);
  70
  71         if (ret < 0)
  72                 return ret;
  73
  74         return (val & CLK32KOUT2_EN) ? 1 : 0;
  75 }
  76
  77 static const struct clk_ops rk808_clkout1_ops = {
  78         .recalc_rate = rk808_clkout_recalc_rate,
  79 };
  80
  81 static const struct clk_ops rk808_clkout2_ops = {
  82         .prepare = rk808_clkout2_prepare,
  83         .unprepare = rk808_clkout2_unprepare,
  84         .is_prepared = rk808_clkout2_is_prepared,
  85         .recalc_rate = rk808_clkout_recalc_rate,
  86 };
  87
  88 static int rk808_clkout_probe(struct platform_device *pdev)
  89 {
  90         struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
  91         struct i2c_client *client = rk808->i2c;
  92         struct device_node *node = client->dev.of_node;
  93         struct clk_init_data init = {};
  94         struct clk **clk_table;
  95         struct rk808_clkout *rk808_clkout;
  96
  97         rk808_clkout = devm_kzalloc(&client->dev,
  98                                     sizeof(*rk808_clkout), GFP_KERNEL);
  99         if (!rk808_clkout)
 100                 return -ENOMEM;
 101
 102         rk808_clkout->rk808 = rk808;
 103
 104         clk_table = devm_kcalloc(&client->dev, RK808_NR_OUTPUT,
 105                                  sizeof(struct clk *), GFP_KERNEL);
 106         if (!clk_table)
 107                 return -ENOMEM;
 108
 109         init.flags = CLK_IS_ROOT;
 110         init.parent_names = NULL;
 111         init.num_parents = 0;
 112         init.name = "rk808-clkout1";
 113         init.ops = &rk808_clkout1_ops;
 114         rk808_clkout->clkout1_hw.init = &init;
 115
 116         /* optional override of the clockname */
 117         of_property_read_string_index(node, "clock-output-names",
 118                                       0, &init.name);
 119
 120         clk_table[0] = devm_clk_register(&client->dev,
 121                                          &rk808_clkout->clkout1_hw);
 122         if (IS_ERR(clk_table[0]))
 123                 return PTR_ERR(clk_table[0]);
 124
 125         init.name = "rk808-clkout2";
 126         init.ops = &rk808_clkout2_ops;
 127         rk808_clkout->clkout2_hw.init = &init;
 128
 129         /* optional override of the clockname */
 130         of_property_read_string_index(node, "clock-output-names",
 131                                       1, &init.name);
 132
 133         clk_table[1] = devm_clk_register(&client->dev,
 134                                          &rk808_clkout->clkout2_hw);
 135         if (IS_ERR(clk_table[1]))
 136                 return PTR_ERR(clk_table[1]);
 137
 138         rk808_clkout->clk_data.clks = clk_table;
 139         rk808_clkout->clk_data.clk_num = RK808_NR_OUTPUT;
 140
 141         return of_clk_add_provider(node, of_clk_src_onecell_get,
 142                                    &rk808_clkout->clk_data);
 143 }
 144
 145 static int rk808_clkout_remove(struct platform_device *pdev)
 146 {
 147         struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
 148         struct i2c_client *client = rk808->i2c;
 149         struct device_node *node = client->dev.of_node;
 150
 151         of_clk_del_provider(node);
 152
 153         return 0;
 154 }
 155
 156 static struct platform_driver rk808_clkout_driver = {
 157         .probe = rk808_clkout_probe,
 158         .remove = rk808_clkout_remove,
 159         .driver         = {
 160                 .name   = "rk808-clkout",
 161         },
 162 };
 163
 164 module_platform_driver(rk808_clkout_driver);
 165
 166 MODULE_DESCRIPTION("Clkout driver for the rk808 series PMICs");
 167 MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
 168 MODULE_LICENSE("GPL");
 169 MODULE_ALIAS("platform:rk808-clkout");