linux/drivers/clk/sunxi/clk-a10-ve.c
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   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
  24static 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
  35struct ve_reset_data {
  36        void __iomem                    *reg;
  37        spinlock_t                      *lock;
  38        struct reset_controller_dev     rcdev;
  39};
  40
  41static 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
  60static 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
  79static 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
  88static const struct reset_control_ops sunxi_ve_reset_ops = {
  89        .assert         = sunxi_ve_reset_assert,
  90        .deassert       = sunxi_ve_reset_deassert,
  91};
  92
  93static 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
 157err_free_reset:
 158        kfree(reset_data);
 159err_del_provider:
 160        of_clk_del_provider(node);
 161err_unregister_clk:
 162        clk_unregister(clk);
 163err_free_gate:
 164        kfree(gate);
 165err_free_div:
 166        kfree(div);
 167err_unmap:
 168        iounmap(reg);
 169}
 170CLK_OF_DECLARE(sun4i_ve, "allwinner,sun4i-a10-ve-clk",
 171               sun4i_ve_clk_setup);
 172