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 struct rk808_clkout {
  26         struct rk808 *rk808;
  27         struct clk_hw           clkout1_hw;
  28         struct clk_hw           clkout2_hw;
  29 };
  30
  31 static unsigned long rk808_clkout_recalc_rate(struct clk_hw *hw,
  32                                               unsigned long parent_rate)
  33 {
  34         return 32768;
  35 }
  36
  37 static 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
  48 static int rk808_clkout2_prepare(struct clk_hw *hw)
  49 {
  50         return rk808_clkout2_enable(hw, true);
  51 }
  52
  53 static void rk808_clkout2_unprepare(struct clk_hw *hw)
  54 {
  55         rk808_clkout2_enable(hw, false);
  56 }
  57
  58 static 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
  74 static const struct clk_ops rk808_clkout1_ops = {
  75         .recalc_rate = rk808_clkout_recalc_rate,
  76 };
  77
  78 static 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
  85 static struct clk_hw *
  86 of_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
  99 static 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 devm_of_clk_add_hw_provider(&pdev->dev, of_clk_rk808_get,
 142                                            rk808_clkout);
 143 }
 144
 145 static struct platform_driver rk808_clkout_driver = {
 146         .probe = rk808_clkout_probe,
 147         .driver         = {
 148                 .name   = "rk808-clkout",
 149         },
 150 };
 151
 152 module_platform_driver(rk808_clkout_driver);
 153
 154 MODULE_DESCRIPTION("Clkout driver for the rk808 series PMICs");
 155 MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
 156 MODULE_LICENSE("GPL");
 157 MODULE_ALIAS("platform:rk808-clkout");