drivers/clk/socfpga/clk-periph.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Copyright 2011-2012 Calxeda, Inc.
   4  *  Copyright (C) 2012-2013 Altera Corporation <www.altera.com>
   5  *
   6  * Based from clk-highbank.c
   7  */
   8 #include <linux/slab.h>
   9 #include <linux/clk-provider.h>
  10 #include <linux/io.h>
  11 #include <linux/of.h>
  12
  13 #include "clk.h"
  14
  15 #define to_socfpga_periph_clk(p) container_of(p, struct socfpga_periph_clk, hw.hw)
  16
  17 static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk,
  18                                              unsigned long parent_rate)
  19 {
  20         struct socfpga_periph_clk *socfpgaclk = to_socfpga_periph_clk(hwclk);
  21         u32 div, val;
  22
  23         if (socfpgaclk->fixed_div) {
  24                 div = socfpgaclk->fixed_div;
  25         } else {
  26                 if (socfpgaclk->div_reg) {
  27                         val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
  28                         val &= GENMASK(socfpgaclk->width - 1, 0);
  29                         parent_rate /= (val + 1);
  30                 }
  31                 div = ((readl(socfpgaclk->hw.reg) & 0x1ff) + 1);
  32         }
  33
  34         return parent_rate / div;
  35 }
  36
  37 static u8 clk_periclk_get_parent(struct clk_hw *hwclk)
  38 {
  39         u32 clk_src;
  40
  41         clk_src = readl(clk_mgr_base_addr + CLKMGR_DBCTRL);
  42         return clk_src & 0x1;
  43 }
  44
  45 static const struct clk_ops periclk_ops = {
  46         .recalc_rate = clk_periclk_recalc_rate,
  47         .get_parent = clk_periclk_get_parent,
  48 };
  49
  50 static __init void __socfpga_periph_init(struct device_node *node,
  51         const struct clk_ops *ops)
  52 {
  53         u32 reg;
  54         struct clk *clk;
  55         struct socfpga_periph_clk *periph_clk;
  56         const char *clk_name = node->name;
  57         const char *parent_name[SOCFPGA_MAX_PARENTS];
  58         struct clk_init_data init;
  59         int rc;
  60         u32 fixed_div;
  61         u32 div_reg[3];
  62
  63         of_property_read_u32(node, "reg", &reg);
  64
  65         periph_clk = kzalloc(sizeof(*periph_clk), GFP_KERNEL);
  66         if (WARN_ON(!periph_clk))
  67                 return;
  68
  69         periph_clk->hw.reg = clk_mgr_base_addr + reg;
  70
  71         rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
  72         if (!rc) {
  73                 periph_clk->div_reg = clk_mgr_base_addr + div_reg[0];
  74                 periph_clk->shift = div_reg[1];
  75                 periph_clk->width = div_reg[2];
  76         } else {
  77                 periph_clk->div_reg = NULL;
  78         }
  79
  80         rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
  81         if (rc)
  82                 periph_clk->fixed_div = 0;
  83         else
  84                 periph_clk->fixed_div = fixed_div;
  85
  86         of_property_read_string(node, "clock-output-names", &clk_name);
  87
  88         init.name = clk_name;
  89         init.ops = ops;
  90         init.flags = 0;
  91
  92         init.num_parents = of_clk_parent_fill(node, parent_name,
  93                                               SOCFPGA_MAX_PARENTS);
  94         init.parent_names = parent_name;
  95
  96         periph_clk->hw.hw.init = &init;
  97
  98         clk = clk_register(NULL, &periph_clk->hw.hw);
  99         if (WARN_ON(IS_ERR(clk))) {
 100                 kfree(periph_clk);
 101                 return;
 102         }
 103         rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 104 }
 105
 106 void __init socfpga_periph_init(struct device_node *node)
 107 {
 108         __socfpga_periph_init(node, &periclk_ops);
 109 }