LXR linux/drivers/clk/sunxi/clk-sun8i-mbus.c

   1/*
   2 * Copyright 2014 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.h>
  18#include <linux/clk-provider.h>
  19#include <linux/slab.h>
  20#include <linux/spinlock.h>
  21#include <linux/of_address.h>
  22
  23#define SUN8I_MBUS_ENABLE       31
  24#define SUN8I_MBUS_MUX_SHIFT    24
  25#define SUN8I_MBUS_MUX_MASK     0x3
  26#define SUN8I_MBUS_DIV_SHIFT    0
  27#define SUN8I_MBUS_DIV_WIDTH    3
  28#define SUN8I_MBUS_MAX_PARENTS  4
  29
  30static DEFINE_SPINLOCK(sun8i_a23_mbus_lock);
  31
  32static void __init sun8i_a23_mbus_setup(struct device_node *node)
  33{
  34        int num_parents = of_clk_get_parent_count(node);
  35        const char **parents;
  36        const char *clk_name = node->name;
  37        struct resource res;
  38        struct clk_divider *div;
  39        struct clk_gate *gate;
  40        struct clk_mux *mux;
  41        struct clk *clk;
  42        void __iomem *reg;
  43        int err;
  44
  45        parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
  46        if (!parents)
  47                return;
  48
  49        reg = of_io_request_and_map(node, 0, of_node_full_name(node));
  50        if (IS_ERR(reg)) {
  51                pr_err("Could not get registers for sun8i-mbus-clk\n");
  52                goto err_free_parents;
  53        }
  54
  55        div = kzalloc(sizeof(*div), GFP_KERNEL);
  56        if (!div)
  57                goto err_unmap;
  58
  59        mux = kzalloc(sizeof(*mux), GFP_KERNEL);
  60        if (!mux)
  61                goto err_free_div;
  62
  63        gate = kzalloc(sizeof(*gate), GFP_KERNEL);
  64        if (!gate)
  65                goto err_free_mux;
  66
  67        of_property_read_string(node, "clock-output-names", &clk_name);
  68        of_clk_parent_fill(node, parents, num_parents);
  69
  70        gate->reg = reg;
  71        gate->bit_idx = SUN8I_MBUS_ENABLE;
  72        gate->lock = &sun8i_a23_mbus_lock;
  73
  74        div->reg = reg;
  75        div->shift = SUN8I_MBUS_DIV_SHIFT;
  76        div->width = SUN8I_MBUS_DIV_WIDTH;
  77        div->lock = &sun8i_a23_mbus_lock;
  78
  79        mux->reg = reg;
  80        mux->shift = SUN8I_MBUS_MUX_SHIFT;
  81        mux->mask = SUN8I_MBUS_MUX_MASK;
  82        mux->lock = &sun8i_a23_mbus_lock;
  83
  84        /* The MBUS clocks needs to be always enabled */
  85        clk = clk_register_composite(NULL, clk_name, parents, num_parents,
  86                                     &mux->hw, &clk_mux_ops,
  87                                     &div->hw, &clk_divider_ops,
  88                                     &gate->hw, &clk_gate_ops,
  89                                     CLK_IS_CRITICAL);
  90        if (IS_ERR(clk))
  91                goto err_free_gate;
  92
  93        err = of_clk_add_provider(node, of_clk_src_simple_get, clk);
  94        if (err)
  95                goto err_unregister_clk;
  96
  97        kfree(parents); /* parents is deep copied */
  98
  99        return;
 100
 101err_unregister_clk:
 102        /* TODO: The composite clock stuff will leak a bit here. */
 103        clk_unregister(clk);
 104err_free_gate:
 105        kfree(gate);
 106err_free_mux:
 107        kfree(mux);
 108err_free_div:
 109        kfree(div);
 110err_unmap:
 111        iounmap(reg);
 112        of_address_to_resource(node, 0, &res);
 113        release_mem_region(res.start, resource_size(&res));
 114err_free_parents:
 115        kfree(parents);
 116}
 117CLK_OF_DECLARE(sun8i_a23_mbus, "allwinner,sun8i-a23-mbus-clk", sun8i_a23_mbus_setup);
 118