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
  30 static DEFINE_SPINLOCK(sun8i_a23_mbus_lock);
  31
  32 static 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
 101 err_unregister_clk:
 102         /* TODO: The composite clock stuff will leak a bit here. */
 103         clk_unregister(clk);
 104 err_free_gate:
 105         kfree(gate);
 106 err_free_mux:
 107         kfree(mux);
 108 err_free_div:
 109         kfree(div);
 110 err_unmap:
 111         iounmap(reg);
 112         of_address_to_resource(node, 0, &res);
 113         release_mem_region(res.start, resource_size(&res));
 114 err_free_parents:
 115         kfree(parents);
 116 }
 117 CLK_OF_DECLARE(sun8i_a23_mbus, "allwinner,sun8i-a23-mbus-clk", sun8i_a23_mbus_setup);