drivers/clk/sunxi/clk-sun8i-bus-gates.c

   1 /*
   2  * Copyright (C) 2015 Jens Kuske <jenskuske@gmail.com>
   3  *
   4  * Based on clk-simple-gates.c, which is:
   5  * Copyright 2015 Maxime Ripard
   6  *
   7  * Maxime Ripard <maxime.ripard@free-electrons.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  */
  19
  20 #include <linux/clk.h>
  21 #include <linux/clk-provider.h>
  22 #include <linux/of.h>
  23 #include <linux/of_address.h>
  24 #include <linux/slab.h>
  25 #include <linux/spinlock.h>
  26
  27 static DEFINE_SPINLOCK(gates_lock);
  28
  29 static void __init sun8i_h3_bus_gates_init(struct device_node *node)
  30 {
  31         static const char * const names[] = { "ahb1", "ahb2", "apb1", "apb2" };
  32         enum { AHB1, AHB2, APB1, APB2, PARENT_MAX } clk_parent;
  33         const char *parents[PARENT_MAX];
  34         struct clk_onecell_data *clk_data;
  35         const char *clk_name;
  36         struct property *prop;
  37         struct resource res;
  38         void __iomem *clk_reg;
  39         void __iomem *reg;
  40         const __be32 *p;
  41         int number, i;
  42         u8 clk_bit;
  43         int index;
  44
  45         reg = of_io_request_and_map(node, 0, of_node_full_name(node));
  46         if (IS_ERR(reg))
  47                 return;
  48
  49         for (i = 0; i < ARRAY_SIZE(names); i++) {
  50                 int idx = of_property_match_string(node, "clock-names",
  51                                                    names[i]);
  52                 if (idx < 0)
  53                         return;
  54
  55                 parents[i] = of_clk_get_parent_name(node, idx);
  56         }
  57
  58         clk_data = kmalloc(sizeof(struct clk_onecell_data), GFP_KERNEL);
  59         if (!clk_data)
  60                 goto err_unmap;
  61
  62         number = of_property_count_u32_elems(node, "clock-indices");
  63         of_property_read_u32_index(node, "clock-indices", number - 1, &number);
  64
  65         clk_data->clks = kcalloc(number + 1, sizeof(struct clk *), GFP_KERNEL);
  66         if (!clk_data->clks)
  67                 goto err_free_data;
  68
  69         i = 0;
  70         of_property_for_each_u32(node, "clock-indices", prop, p, index) {
  71                 of_property_read_string_index(node, "clock-output-names",
  72                                               i, &clk_name);
  73
  74                 if (index == 17 || (index >= 29 && index <= 31))
  75                         clk_parent = AHB2;
  76                 else if (index <= 63 || index >= 128)
  77                         clk_parent = AHB1;
  78                 else if (index >= 64 && index <= 95)
  79                         clk_parent = APB1;
  80                 else if (index >= 96 && index <= 127)
  81                         clk_parent = APB2;
  82
  83                 clk_reg = reg + 4 * (index / 32);
  84                 clk_bit = index % 32;
  85
  86                 clk_data->clks[index] = clk_register_gate(NULL, clk_name,
  87                                                           parents[clk_parent],
  88                                                           0, clk_reg, clk_bit,
  89                                                           0, &gates_lock);
  90                 i++;
  91
  92                 if (IS_ERR(clk_data->clks[index])) {
  93                         WARN_ON(true);
  94                         continue;
  95                 }
  96         }
  97
  98         clk_data->clk_num = number + 1;
  99         of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
 100
 101         return;
 102
 103 err_free_data:
 104         kfree(clk_data);
 105 err_unmap:
 106         iounmap(reg);
 107         of_address_to_resource(node, 0, &res);
 108         release_mem_region(res.start, resource_size(&res));
 109 }
 110
 111 CLK_OF_DECLARE(sun8i_h3_bus_gates, "allwinner,sun8i-h3-bus-gates-clk",
 112                sun8i_h3_bus_gates_init);