drivers/clk/sunxi/clk-a10-ve.c

   1 /*
   2  * Copyright 2015 Chen-Yu Tsai
   3  *
   4  * Chen-Yu Tsai <wens@csie.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/clk-provider.h>
  18 #include <linux/of.h>
  19 #include <linux/of_address.h>
  20 #include <linux/reset-controller.h>
  21 #include <linux/slab.h>
  22 #include <linux/spinlock.h>
  23
  24 static DEFINE_SPINLOCK(ve_lock);
  25
  26 #define SUN4I_VE_ENABLE         31
  27 #define SUN4I_VE_DIVIDER_SHIFT  16
  28 #define SUN4I_VE_DIVIDER_WIDTH  3
  29 #define SUN4I_VE_RESET          0
  30
  31 /**
  32  * sunxi_ve_reset... - reset bit in ve clk registers handling
  33  */
  34
  35 struct ve_reset_data {
  36         void __iomem                    *reg;
  37         spinlock_t                      *lock;
  38         struct reset_controller_dev     rcdev;
  39 };
  40
  41 static int sunxi_ve_reset_assert(struct reset_controller_dev *rcdev,
  42                                  unsigned long id)
  43 {
  44         struct ve_reset_data *data = container_of(rcdev,
  45                                                   struct ve_reset_data,
  46                                                   rcdev);
  47         unsigned long flags;
  48         u32 reg;
  49
  50         spin_lock_irqsave(data->lock, flags);
  51
  52         reg = readl(data->reg);
  53         writel(reg & ~BIT(SUN4I_VE_RESET), data->reg);
  54
  55         spin_unlock_irqrestore(data->lock, flags);
  56
  57         return 0;
  58 }
  59
  60 static int sunxi_ve_reset_deassert(struct reset_controller_dev *rcdev,
  61                                    unsigned long id)
  62 {
  63         struct ve_reset_data *data = container_of(rcdev,
  64                                                   struct ve_reset_data,
  65                                                   rcdev);
  66         unsigned long flags;
  67         u32 reg;
  68
  69         spin_lock_irqsave(data->lock, flags);
  70
  71         reg = readl(data->reg);
  72         writel(reg | BIT(SUN4I_VE_RESET), data->reg);
  73
  74         spin_unlock_irqrestore(data->lock, flags);
  75
  76         return 0;
  77 }
  78
  79 static int sunxi_ve_of_xlate(struct reset_controller_dev *rcdev,
  80                              const struct of_phandle_args *reset_spec)
  81 {
  82         if (WARN_ON(reset_spec->args_count != 0))
  83                 return -EINVAL;
  84
  85         return 0;
  86 }
  87
  88 static const struct reset_control_ops sunxi_ve_reset_ops = {
  89         .assert         = sunxi_ve_reset_assert,
  90         .deassert       = sunxi_ve_reset_deassert,
  91 };
  92
  93 static void __init sun4i_ve_clk_setup(struct device_node *node)
  94 {
  95         struct clk *clk;
  96         struct clk_divider *div;
  97         struct clk_gate *gate;
  98         struct ve_reset_data *reset_data;
  99         const char *parent;
 100         const char *clk_name = node->name;
 101         void __iomem *reg;
 102         int err;
 103
 104         reg = of_io_request_and_map(node, 0, of_node_full_name(node));
 105         if (IS_ERR(reg))
 106                 return;
 107
 108         div = kzalloc(sizeof(*div), GFP_KERNEL);
 109         if (!div)
 110                 goto err_unmap;
 111
 112         gate = kzalloc(sizeof(*gate), GFP_KERNEL);
 113         if (!gate)
 114                 goto err_free_div;
 115
 116         of_property_read_string(node, "clock-output-names", &clk_name);
 117         parent = of_clk_get_parent_name(node, 0);
 118
 119         gate->reg = reg;
 120         gate->bit_idx = SUN4I_VE_ENABLE;
 121         gate->lock = &ve_lock;
 122
 123         div->reg = reg;
 124         div->shift = SUN4I_VE_DIVIDER_SHIFT;
 125         div->width = SUN4I_VE_DIVIDER_WIDTH;
 126         div->lock = &ve_lock;
 127
 128         clk = clk_register_composite(NULL, clk_name, &parent, 1,
 129                                      NULL, NULL,
 130                                      &div->hw, &clk_divider_ops,
 131                                      &gate->hw, &clk_gate_ops,
 132                                      CLK_SET_RATE_PARENT);
 133         if (IS_ERR(clk))
 134                 goto err_free_gate;
 135
 136         err = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 137         if (err)
 138                 goto err_unregister_clk;
 139
 140         reset_data = kzalloc(sizeof(*reset_data), GFP_KERNEL);
 141         if (!reset_data)
 142                 goto err_del_provider;
 143
 144         reset_data->reg = reg;
 145         reset_data->lock = &ve_lock;
 146         reset_data->rcdev.nr_resets = 1;
 147         reset_data->rcdev.ops = &sunxi_ve_reset_ops;
 148         reset_data->rcdev.of_node = node;
 149         reset_data->rcdev.of_xlate = sunxi_ve_of_xlate;
 150         reset_data->rcdev.of_reset_n_cells = 0;
 151         err = reset_controller_register(&reset_data->rcdev);
 152         if (err)
 153                 goto err_free_reset;
 154
 155         return;
 156
 157 err_free_reset:
 158         kfree(reset_data);
 159 err_del_provider:
 160         of_clk_del_provider(node);
 161 err_unregister_clk:
 162         clk_unregister(clk);
 163 err_free_gate:
 164         kfree(gate);
 165 err_free_div:
 166         kfree(div);
 167 err_unmap:
 168         iounmap(reg);
 169 }
 170 CLK_OF_DECLARE(sun4i_ve, "allwinner,sun4i-a10-ve-clk",
 171                sun4i_ve_clk_setup);