kernel/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
  24 static DEFINE_SPINLOCK(hosc_lock);
  25
  26 static 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
  68 err_free_gate:
  69         kfree(gate);
  70 err_free_fixed:
  71         kfree(fixed);
  72 }
  73 CLK_OF_DECLARE(sun4i_osc, "allwinner,sun4i-a10-osc-clk", sun4i_osc_clk_setup);