LXR linux/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-provider.h>
  21#include <linux/of.h>
  22#include <linux/of_address.h>
  23#include <linux/slab.h>
  24#include <linux/spinlock.h>
  25
  26static DEFINE_SPINLOCK(gates_lock);
  27
  28static void __init sun8i_h3_bus_gates_init(struct device_node *node)
  29{
  30        static const char * const names[] = { "ahb1", "ahb2", "apb1", "apb2" };
  31        enum { AHB1, AHB2, APB1, APB2, PARENT_MAX } clk_parent;
  32        const char *parents[PARENT_MAX];
  33        struct clk_onecell_data *clk_data;
  34        const char *clk_name;
  35        struct property *prop;
  36        struct resource res;
  37        void __iomem *clk_reg;
  38        void __iomem *reg;
  39        const __be32 *p;
  40        int number, i;
  41        u8 clk_bit;
  42        int index;
  43
  44        reg = of_io_request_and_map(node, 0, of_node_full_name(node));
  45        if (IS_ERR(reg))
  46                return;
  47
  48        for (i = 0; i < ARRAY_SIZE(names); i++) {
  49                int idx = of_property_match_string(node, "clock-names",
  50                                                   names[i]);
  51                if (idx < 0)
  52                        return;
  53
  54                parents[i] = of_clk_get_parent_name(node, idx);
  55        }
  56
  57        clk_data = kmalloc(sizeof(struct clk_onecell_data), GFP_KERNEL);
  58        if (!clk_data)
  59                goto err_unmap;
  60
  61        number = of_property_count_u32_elems(node, "clock-indices");
  62        of_property_read_u32_index(node, "clock-indices", number - 1, &number);
  63
  64        clk_data->clks = kcalloc(number + 1, sizeof(struct clk *), GFP_KERNEL);
  65        if (!clk_data->clks)
  66                goto err_free_data;
  67
  68        i = 0;
  69        of_property_for_each_u32(node, "clock-indices", prop, p, index) {
  70                of_property_read_string_index(node, "clock-output-names",
  71                                              i, &clk_name);
  72
  73                if (index == 17 || (index >= 29 && index <= 31))
  74                        clk_parent = AHB2;
  75                else if (index <= 63 || index >= 128)
  76                        clk_parent = AHB1;
  77                else if (index >= 64 && index <= 95)
  78                        clk_parent = APB1;
  79                else if (index >= 96 && index <= 127)
  80                        clk_parent = APB2;
  81
  82                clk_reg = reg + 4 * (index / 32);
  83                clk_bit = index % 32;
  84
  85                clk_data->clks[index] = clk_register_gate(NULL, clk_name,
  86                                                          parents[clk_parent],
  87                                                          0, clk_reg, clk_bit,
  88                                                          0, &gates_lock);
  89                i++;
  90
  91                if (IS_ERR(clk_data->clks[index])) {
  92                        WARN_ON(true);
  93                        continue;
  94                }
  95        }
  96
  97        clk_data->clk_num = number + 1;
  98        of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
  99
 100        return;
 101
 102err_free_data:
 103        kfree(clk_data);
 104err_unmap:
 105        iounmap(reg);
 106        of_address_to_resource(node, 0, &res);
 107        release_mem_region(res.start, resource_size(&res));
 108}
 109
 110CLK_OF_DECLARE(sun8i_h3_bus_gates, "allwinner,sun8i-h3-bus-gates-clk",
 111               sun8i_h3_bus_gates_init);
 112CLK_OF_DECLARE(sun8i_a83t_bus_gates, "allwinner,sun8i-a83t-bus-gates-clk",
 113               sun8i_h3_bus_gates_init);
 114