drivers/clk/clk-moxart.c

   1 /*
   2  * MOXA ART SoCs clock driver.
   3  *
   4  * Copyright (C) 2013 Jonas Jensen
   5  *
   6  * Jonas Jensen <jonas.jensen@gmail.com>
   7  *
   8  * This file is licensed under the terms of the GNU General Public
   9  * License version 2.  This program is licensed "as is" without any
  10  * warranty of any kind, whether express or implied.
  11  */
  12
  13 #include <linux/clk.h>
  14 #include <linux/clk-provider.h>
  15 #include <linux/io.h>
  16 #include <linux/of_address.h>
  17 #include <linux/clkdev.h>
  18
  19 static void __init moxart_of_pll_clk_init(struct device_node *node)
  20 {
  21         static void __iomem *base;
  22         struct clk_hw *hw;
  23         struct clk *ref_clk;
  24         unsigned int mul;
  25         const char *name = node->name;
  26         const char *parent_name;
  27
  28         of_property_read_string(node, "clock-output-names", &name);
  29         parent_name = of_clk_get_parent_name(node, 0);
  30
  31         base = of_iomap(node, 0);
  32         if (!base) {
  33                 pr_err("%s: of_iomap failed\n", node->full_name);
  34                 return;
  35         }
  36
  37         mul = readl(base + 0x30) >> 3 & 0x3f;
  38         iounmap(base);
  39
  40         ref_clk = of_clk_get(node, 0);
  41         if (IS_ERR(ref_clk)) {
  42                 pr_err("%s: of_clk_get failed\n", node->full_name);
  43                 return;
  44         }
  45
  46         hw = clk_hw_register_fixed_factor(NULL, name, parent_name, 0, mul, 1);
  47         if (IS_ERR(hw)) {
  48                 pr_err("%s: failed to register clock\n", node->full_name);
  49                 return;
  50         }
  51
  52         clk_hw_register_clkdev(hw, NULL, name);
  53         of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
  54 }
  55 CLK_OF_DECLARE(moxart_pll_clock, "moxa,moxart-pll-clock",
  56                moxart_of_pll_clk_init);
  57
  58 static void __init moxart_of_apb_clk_init(struct device_node *node)
  59 {
  60         static void __iomem *base;
  61         struct clk_hw *hw;
  62         struct clk *pll_clk;
  63         unsigned int div, val;
  64         unsigned int div_idx[] = { 2, 3, 4, 6, 8};
  65         const char *name = node->name;
  66         const char *parent_name;
  67
  68         of_property_read_string(node, "clock-output-names", &name);
  69         parent_name = of_clk_get_parent_name(node, 0);
  70
  71         base = of_iomap(node, 0);
  72         if (!base) {
  73                 pr_err("%s: of_iomap failed\n", node->full_name);
  74                 return;
  75         }
  76
  77         val = readl(base + 0xc) >> 4 & 0x7;
  78         iounmap(base);
  79
  80         if (val > 4)
  81                 val = 0;
  82         div = div_idx[val] * 2;
  83
  84         pll_clk = of_clk_get(node, 0);
  85         if (IS_ERR(pll_clk)) {
  86                 pr_err("%s: of_clk_get failed\n", node->full_name);
  87                 return;
  88         }
  89
  90         hw = clk_hw_register_fixed_factor(NULL, name, parent_name, 0, 1, div);
  91         if (IS_ERR(hw)) {
  92                 pr_err("%s: failed to register clock\n", node->full_name);
  93                 return;
  94         }
  95
  96         clk_hw_register_clkdev(hw, NULL, name);
  97         of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
  98 }
  99 CLK_OF_DECLARE(moxart_apb_clock, "moxa,moxart-apb-clock",
 100                moxart_of_apb_clk_init);