LXR linux/drivers/clk/rockchip/clk-rockchip.c

   1/*
   2 * Copyright (c) 2013 MundoReader S.L.
   3 * Author: Heiko Stuebner <heiko@sntech.de>
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License as published by
   7 * the Free Software Foundation; either version 2 of the License, or
   8 * (at your option) any later version.
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 * GNU General Public License for more details.
  14 */
  15
  16#include <linux/clk-provider.h>
  17#include <linux/clkdev.h>
  18#include <linux/of.h>
  19#include <linux/of_address.h>
  20
  21static DEFINE_SPINLOCK(clk_lock);
  22
  23/*
  24 * Gate clocks
  25 */
  26
  27static void __init rk2928_gate_clk_init(struct device_node *node)
  28{
  29        struct clk_onecell_data *clk_data;
  30        const char *clk_parent;
  31        const char *clk_name;
  32        void __iomem *reg;
  33        void __iomem *reg_idx;
  34        int flags;
  35        int qty;
  36        int reg_bit;
  37        int clkflags = CLK_SET_RATE_PARENT;
  38        int i;
  39
  40        qty = of_property_count_strings(node, "clock-output-names");
  41        if (qty < 0) {
  42                pr_err("%s: error in clock-output-names %d\n", __func__, qty);
  43                return;
  44        }
  45
  46        if (qty == 0) {
  47                pr_info("%s: nothing to do\n", __func__);
  48                return;
  49        }
  50
  51        reg = of_iomap(node, 0);
  52        if (!reg)
  53                return;
  54
  55        clk_data = kzalloc(sizeof(struct clk_onecell_data), GFP_KERNEL);
  56        if (!clk_data) {
  57                iounmap(reg);
  58                return;
  59        }
  60
  61        clk_data->clks = kzalloc(qty * sizeof(struct clk *), GFP_KERNEL);
  62        if (!clk_data->clks) {
  63                kfree(clk_data);
  64                iounmap(reg);
  65                return;
  66        }
  67
  68        flags = CLK_GATE_HIWORD_MASK | CLK_GATE_SET_TO_DISABLE;
  69
  70        for (i = 0; i < qty; i++) {
  71                of_property_read_string_index(node, "clock-output-names",
  72                                              i, &clk_name);
  73
  74                /* ignore empty slots */
  75                if (!strcmp("reserved", clk_name))
  76                        continue;
  77
  78                clk_parent = of_clk_get_parent_name(node, i);
  79
  80                /* keep all gates untouched for now */
  81                clkflags |= CLK_IGNORE_UNUSED;
  82
  83                reg_idx = reg + (4 * (i / 16));
  84                reg_bit = (i % 16);
  85
  86                clk_data->clks[i] = clk_register_gate(NULL, clk_name,
  87                                                      clk_parent, clkflags,
  88                                                      reg_idx, reg_bit,
  89                                                      flags,
  90                                                      &clk_lock);
  91                WARN_ON(IS_ERR(clk_data->clks[i]));
  92        }
  93
  94        clk_data->clk_num = qty;
  95
  96        of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
  97}
  98CLK_OF_DECLARE(rk2928_gate, "rockchip,rk2928-gate-clk", rk2928_gate_clk_init);
  99