drivers/clk/keystone/syscon-clk.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2020 Texas Instruments Incorporated - https://www.ti.com/
   4  */
   5
   6 #include <linux/clk-provider.h>
   7 #include <linux/mfd/syscon.h>
   8 #include <linux/module.h>
   9 #include <linux/platform_device.h>
  10 #include <linux/regmap.h>
  11
  12 struct ti_syscon_gate_clk_priv {
  13         struct clk_hw hw;
  14         struct regmap *regmap;
  15         u32 reg;
  16         u32 idx;
  17 };
  18
  19 struct ti_syscon_gate_clk_data {
  20         char *name;
  21         u32 offset;
  22         u32 bit_idx;
  23 };
  24
  25 static struct
  26 ti_syscon_gate_clk_priv *to_ti_syscon_gate_clk_priv(struct clk_hw *hw)
  27 {
  28         return container_of(hw, struct ti_syscon_gate_clk_priv, hw);
  29 }
  30
  31 static int ti_syscon_gate_clk_enable(struct clk_hw *hw)
  32 {
  33         struct ti_syscon_gate_clk_priv *priv = to_ti_syscon_gate_clk_priv(hw);
  34
  35         return regmap_write_bits(priv->regmap, priv->reg, priv->idx,
  36                                  priv->idx);
  37 }
  38
  39 static void ti_syscon_gate_clk_disable(struct clk_hw *hw)
  40 {
  41         struct ti_syscon_gate_clk_priv *priv = to_ti_syscon_gate_clk_priv(hw);
  42
  43         regmap_write_bits(priv->regmap, priv->reg, priv->idx, 0);
  44 }
  45
  46 static int ti_syscon_gate_clk_is_enabled(struct clk_hw *hw)
  47 {
  48         unsigned int val;
  49         struct ti_syscon_gate_clk_priv *priv = to_ti_syscon_gate_clk_priv(hw);
  50
  51         regmap_read(priv->regmap, priv->reg, &val);
  52
  53         return !!(val & priv->idx);
  54 }
  55
  56 static const struct clk_ops ti_syscon_gate_clk_ops = {
  57         .enable         = ti_syscon_gate_clk_enable,
  58         .disable        = ti_syscon_gate_clk_disable,
  59         .is_enabled     = ti_syscon_gate_clk_is_enabled,
  60 };
  61
  62 static struct clk_hw
  63 *ti_syscon_gate_clk_register(struct device *dev, struct regmap *regmap,
  64                              const struct ti_syscon_gate_clk_data *data)
  65 {
  66         struct ti_syscon_gate_clk_priv *priv;
  67         struct clk_init_data init;
  68         int ret;
  69
  70         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  71         if (!priv)
  72                 return ERR_PTR(-ENOMEM);
  73
  74         init.name = data->name;
  75         init.ops = &ti_syscon_gate_clk_ops;
  76         init.parent_names = NULL;
  77         init.num_parents = 0;
  78         init.flags = 0;
  79
  80         priv->regmap = regmap;
  81         priv->reg = data->offset;
  82         priv->idx = BIT(data->bit_idx);
  83         priv->hw.init = &init;
  84
  85         ret = devm_clk_hw_register(dev, &priv->hw);
  86         if (ret)
  87                 return ERR_PTR(ret);
  88
  89         return &priv->hw;
  90 }
  91
  92 static int ti_syscon_gate_clk_probe(struct platform_device *pdev)
  93 {
  94         const struct ti_syscon_gate_clk_data *data, *p;
  95         struct clk_hw_onecell_data *hw_data;
  96         struct device *dev = &pdev->dev;
  97         struct regmap *regmap;
  98         int num_clks, i;
  99
 100         data = device_get_match_data(dev);
 101         if (!data)
 102                 return -EINVAL;
 103
 104         regmap = syscon_node_to_regmap(dev->of_node);
 105         if (IS_ERR(regmap)) {
 106                 if (PTR_ERR(regmap) == -EPROBE_DEFER)
 107                         return -EPROBE_DEFER;
 108                 dev_err(dev, "failed to find parent regmap\n");
 109                 return PTR_ERR(regmap);
 110         }
 111
 112         num_clks = 0;
 113         for (p = data; p->name; p++)
 114                 num_clks++;
 115
 116         hw_data = devm_kzalloc(dev, struct_size(hw_data, hws, num_clks),
 117                                GFP_KERNEL);
 118         if (!hw_data)
 119                 return -ENOMEM;
 120
 121         hw_data->num = num_clks;
 122
 123         for (i = 0; i < num_clks; i++) {
 124                 hw_data->hws[i] = ti_syscon_gate_clk_register(dev, regmap,
 125                                                               &data[i]);
 126                 if (IS_ERR(hw_data->hws[i]))
 127                         dev_warn(dev, "failed to register %s\n",
 128                                  data[i].name);
 129         }
 130
 131         return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
 132                                            hw_data);
 133 }
 134
 135 #define TI_SYSCON_CLK_GATE(_name, _offset, _bit_idx)    \
 136         {                                               \
 137                 .name = _name,                          \
 138                 .offset = (_offset),                    \
 139                 .bit_idx = (_bit_idx),                  \
 140         }
 141
 142 static const struct ti_syscon_gate_clk_data am654_clk_data[] = {
 143         TI_SYSCON_CLK_GATE("ehrpwm_tbclk0", 0x0, 0),
 144         TI_SYSCON_CLK_GATE("ehrpwm_tbclk1", 0x4, 0),
 145         TI_SYSCON_CLK_GATE("ehrpwm_tbclk2", 0x8, 0),
 146         TI_SYSCON_CLK_GATE("ehrpwm_tbclk3", 0xc, 0),
 147         TI_SYSCON_CLK_GATE("ehrpwm_tbclk4", 0x10, 0),
 148         TI_SYSCON_CLK_GATE("ehrpwm_tbclk5", 0x14, 0),
 149         { /* Sentinel */ },
 150 };
 151
 152 static const struct of_device_id ti_syscon_gate_clk_ids[] = {
 153         {
 154                 .compatible = "ti,am654-ehrpwm-tbclk",
 155                 .data = &am654_clk_data,
 156         },
 157         { }
 158 };
 159 MODULE_DEVICE_TABLE(of, ti_syscon_gate_clk_ids);
 160
 161 static struct platform_driver ti_syscon_gate_clk_driver = {
 162         .probe = ti_syscon_gate_clk_probe,
 163         .driver = {
 164                 .name = "ti-syscon-gate-clk",
 165                 .of_match_table = ti_syscon_gate_clk_ids,
 166         },
 167 };
 168 module_platform_driver(ti_syscon_gate_clk_driver);
 169
 170 MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");
 171 MODULE_DESCRIPTION("Syscon backed gate-clock driver");
 172 MODULE_LICENSE("GPL");