drivers/clk/socfpga/clk-gate-s10.c

   1 // SPDX-License-Identifier:     GPL-2.0
   2 /*
   3  * Copyright (C) 2017, Intel Corporation
   4  */
   5 #include <linux/clk-provider.h>
   6 #include <linux/io.h>
   7 #include <linux/slab.h>
   8 #include "stratix10-clk.h"
   9 #include "clk.h"
  10
  11 #define SOCFPGA_CS_PDBG_CLK     "cs_pdbg_clk"
  12 #define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw)
  13
  14 static unsigned long socfpga_gate_clk_recalc_rate(struct clk_hw *hwclk,
  15                                                   unsigned long parent_rate)
  16 {
  17         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
  18         u32 div = 1, val;
  19
  20         if (socfpgaclk->fixed_div) {
  21                 div = socfpgaclk->fixed_div;
  22         } else if (socfpgaclk->div_reg) {
  23                 val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
  24                 val &= GENMASK(socfpgaclk->width - 1, 0);
  25                 div = (1 << val);
  26         }
  27         return parent_rate / div;
  28 }
  29
  30 static unsigned long socfpga_dbg_clk_recalc_rate(struct clk_hw *hwclk,
  31                                                   unsigned long parent_rate)
  32 {
  33         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
  34         u32 div = 1, val;
  35
  36         val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
  37         val &= GENMASK(socfpgaclk->width - 1, 0);
  38         div = (1 << val);
  39         div = div ? 4 : 1;
  40
  41         return parent_rate / div;
  42 }
  43
  44 static u8 socfpga_gate_get_parent(struct clk_hw *hwclk)
  45 {
  46         struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
  47         u32 mask;
  48         u8 parent = 0;
  49
  50         if (socfpgaclk->bypass_reg) {
  51                 mask = (0x1 << socfpgaclk->bypass_shift);
  52                 parent = ((readl(socfpgaclk->bypass_reg) & mask) >>
  53                           socfpgaclk->bypass_shift);
  54         }
  55         return parent;
  56 }
  57
  58 static struct clk_ops gateclk_ops = {
  59         .recalc_rate = socfpga_gate_clk_recalc_rate,
  60         .get_parent = socfpga_gate_get_parent,
  61 };
  62
  63 static const struct clk_ops dbgclk_ops = {
  64         .recalc_rate = socfpga_dbg_clk_recalc_rate,
  65         .get_parent = socfpga_gate_get_parent,
  66 };
  67
  68 struct clk *s10_register_gate(const char *name, const char *parent_name,
  69                               const char * const *parent_names,
  70                               u8 num_parents, unsigned long flags,
  71                               void __iomem *regbase, unsigned long gate_reg,
  72                               unsigned long gate_idx, unsigned long div_reg,
  73                               unsigned long div_offset, u8 div_width,
  74                               unsigned long bypass_reg, u8 bypass_shift,
  75                               u8 fixed_div)
  76 {
  77         struct clk *clk;
  78         struct socfpga_gate_clk *socfpga_clk;
  79         struct clk_init_data init;
  80
  81         socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
  82         if (!socfpga_clk)
  83                 return NULL;
  84
  85         socfpga_clk->hw.reg = regbase + gate_reg;
  86         socfpga_clk->hw.bit_idx = gate_idx;
  87
  88         gateclk_ops.enable = clk_gate_ops.enable;
  89         gateclk_ops.disable = clk_gate_ops.disable;
  90
  91         socfpga_clk->fixed_div = fixed_div;
  92
  93         if (div_reg)
  94                 socfpga_clk->div_reg = regbase + div_reg;
  95         else
  96                 socfpga_clk->div_reg = NULL;
  97
  98         socfpga_clk->width = div_width;
  99         socfpga_clk->shift = div_offset;
 100
 101         if (bypass_reg)
 102                 socfpga_clk->bypass_reg = regbase + bypass_reg;
 103         else
 104                 socfpga_clk->bypass_reg = NULL;
 105         socfpga_clk->bypass_shift = bypass_shift;
 106
 107         if (streq(name, "cs_pdbg_clk"))
 108                 init.ops = &dbgclk_ops;
 109         else
 110                 init.ops = &gateclk_ops;
 111
 112         init.name = name;
 113         init.flags = flags;
 114
 115         init.num_parents = num_parents;
 116         init.parent_names = parent_names ? parent_names : &parent_name;
 117         socfpga_clk->hw.hw.init = &init;
 118
 119         clk = clk_register(NULL, &socfpga_clk->hw.hw);
 120         if (WARN_ON(IS_ERR(clk))) {
 121                 kfree(socfpga_clk);
 122                 return NULL;
 123         }
 124
 125         return clk;
 126 }