drivers/clk/socfpga/clk-pll.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 #include <linux/of_address.h>
  13
  14 #include "clk.h"
  15
  16 /* Clock bypass bits */
  17 #define MAINPLL_BYPASS          (1<<0)
  18 #define SDRAMPLL_BYPASS         (1<<1)
  19 #define SDRAMPLL_SRC_BYPASS     (1<<2)
  20 #define PERPLL_BYPASS           (1<<3)
  21 #define PERPLL_SRC_BYPASS       (1<<4)
  22
  23 #define SOCFPGA_PLL_BG_PWRDWN           0
  24 #define SOCFPGA_PLL_EXT_ENA             1
  25 #define SOCFPGA_PLL_PWR_DOWN            2
  26 #define SOCFPGA_PLL_DIVF_MASK           0x0000FFF8
  27 #define SOCFPGA_PLL_DIVF_SHIFT          3
  28 #define SOCFPGA_PLL_DIVQ_MASK           0x003F0000
  29 #define SOCFPGA_PLL_DIVQ_SHIFT          16
  30
  31 #define CLK_MGR_PLL_CLK_SRC_SHIFT       22
  32 #define CLK_MGR_PLL_CLK_SRC_MASK        0x3
  33
  34 #define to_socfpga_clk(p) container_of(p, struct socfpga_pll, hw.hw)
  35
  36 void __iomem *clk_mgr_base_addr;
  37
  38 static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
  39                                          unsigned long parent_rate)
  40 {
  41         struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
  42         unsigned long divf, divq, reg;
  43         unsigned long long vco_freq;
  44         unsigned long bypass;
  45
  46         reg = readl(socfpgaclk->hw.reg);
  47         bypass = readl(clk_mgr_base_addr + CLKMGR_BYPASS);
  48         if (bypass & MAINPLL_BYPASS)
  49                 return parent_rate;
  50
  51         divf = (reg & SOCFPGA_PLL_DIVF_MASK) >> SOCFPGA_PLL_DIVF_SHIFT;
  52         divq = (reg & SOCFPGA_PLL_DIVQ_MASK) >> SOCFPGA_PLL_DIVQ_SHIFT;
  53         vco_freq = (unsigned long long)parent_rate * (divf + 1);
  54         do_div(vco_freq, (1 + divq));
  55         return (unsigned long)vco_freq;
  56 }
  57
  58 static u8 clk_pll_get_parent(struct clk_hw *hwclk)
  59 {
  60         u32 pll_src;
  61         struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
  62
  63         pll_src = readl(socfpgaclk->hw.reg);
  64         return (pll_src >> CLK_MGR_PLL_CLK_SRC_SHIFT) &
  65                         CLK_MGR_PLL_CLK_SRC_MASK;
  66 }
  67
  68 static const struct clk_ops clk_pll_ops = {
  69         .recalc_rate = clk_pll_recalc_rate,
  70         .get_parent = clk_pll_get_parent,
  71 };
  72
  73 static __init struct clk *__socfpga_pll_init(struct device_node *node,
  74         const struct clk_ops *ops)
  75 {
  76         u32 reg;
  77         struct clk *clk;
  78         struct socfpga_pll *pll_clk;
  79         const char *clk_name = node->name;
  80         const char *parent_name[SOCFPGA_MAX_PARENTS];
  81         struct clk_init_data init;
  82         struct device_node *clkmgr_np;
  83         int rc;
  84
  85         of_property_read_u32(node, "reg", &reg);
  86
  87         pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
  88         if (WARN_ON(!pll_clk))
  89                 return NULL;
  90
  91         clkmgr_np = of_find_compatible_node(NULL, NULL, "altr,clk-mgr");
  92         clk_mgr_base_addr = of_iomap(clkmgr_np, 0);
  93         of_node_put(clkmgr_np);
  94         BUG_ON(!clk_mgr_base_addr);
  95         pll_clk->hw.reg = clk_mgr_base_addr + reg;
  96
  97         of_property_read_string(node, "clock-output-names", &clk_name);
  98
  99         init.name = clk_name;
 100         init.ops = ops;
 101         init.flags = 0;
 102
 103         init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS);
 104         init.parent_names = parent_name;
 105         pll_clk->hw.hw.init = &init;
 106
 107         pll_clk->hw.bit_idx = SOCFPGA_PLL_EXT_ENA;
 108
 109         clk = clk_register(NULL, &pll_clk->hw.hw);
 110         if (WARN_ON(IS_ERR(clk))) {
 111                 kfree(pll_clk);
 112                 return NULL;
 113         }
 114         rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 115         return clk;
 116 }
 117
 118 void __init socfpga_pll_init(struct device_node *node)
 119 {
 120         __socfpga_pll_init(node, &clk_pll_ops);
 121 }