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