LXR linux/drivers/clk/sunxi/clk-a10-hosc.c

   1/*
   2 * Copyright 2013 Emilio López
   3 *
   4 * Emilio López <emilio@elopez.com.ar>
   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-provider.h>
  18#include <linux/clkdev.h>
  19#include <linux/of.h>
  20#include <linux/of_address.h>
  21
  22#define SUNXI_OSC24M_GATE       0
  23
  24static DEFINE_SPINLOCK(hosc_lock);
  25
  26static void __init sun4i_osc_clk_setup(struct device_node *node)
  27{
  28        struct clk *clk;
  29        struct clk_fixed_rate *fixed;
  30        struct clk_gate *gate;
  31        const char *clk_name = node->name;
  32        u32 rate;
  33
  34        if (of_property_read_u32(node, "clock-frequency", &rate))
  35                return;
  36
  37        /* allocate fixed-rate and gate clock structs */
  38        fixed = kzalloc(sizeof(struct clk_fixed_rate), GFP_KERNEL);
  39        if (!fixed)
  40                return;
  41        gate = kzalloc(sizeof(struct clk_gate), GFP_KERNEL);
  42        if (!gate)
  43                goto err_free_fixed;
  44
  45        of_property_read_string(node, "clock-output-names", &clk_name);
  46
  47        /* set up gate and fixed rate properties */
  48        gate->reg = of_iomap(node, 0);
  49        gate->bit_idx = SUNXI_OSC24M_GATE;
  50        gate->lock = &hosc_lock;
  51        fixed->fixed_rate = rate;
  52
  53        clk = clk_register_composite(NULL, clk_name,
  54                        NULL, 0,
  55                        NULL, NULL,
  56                        &fixed->hw, &clk_fixed_rate_ops,
  57                        &gate->hw, &clk_gate_ops,
  58                        CLK_IS_ROOT);
  59
  60        if (IS_ERR(clk))
  61                goto err_free_gate;
  62
  63        of_clk_add_provider(node, of_clk_src_simple_get, clk);
  64        clk_register_clkdev(clk, clk_name, NULL);
  65
  66        return;
  67
  68err_free_gate:
  69        kfree(gate);
  70err_free_fixed:
  71        kfree(fixed);
  72}
  73CLK_OF_DECLARE(sun4i_osc, "allwinner,sun4i-a10-osc-clk", sun4i_osc_clk_setup);
  74