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, 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_hw *s10_register_gate(const struct stratix10_gate_clock *clks, void __iomem *regbase)
  69 {
  70         struct clk_hw *hw_clk;
  71         struct socfpga_gate_clk *socfpga_clk;
  72         struct clk_init_data init;
  73         const char *parent_name = clks->parent_name;
  74         int ret;
  75
  76         socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
  77         if (!socfpga_clk)
  78                 return NULL;
  79
  80         socfpga_clk->hw.reg = regbase + clks->gate_reg;
  81         socfpga_clk->hw.bit_idx = clks->gate_idx;
  82
  83         gateclk_ops.enable = clk_gate_ops.enable;
  84         gateclk_ops.disable = clk_gate_ops.disable;
  85
  86         socfpga_clk->fixed_div = clks->fixed_div;
  87
  88         if (clks->div_reg)
  89                 socfpga_clk->div_reg = regbase + clks->div_reg;
  90         else
  91                 socfpga_clk->div_reg = NULL;
  92
  93         socfpga_clk->width = clks->div_width;
  94         socfpga_clk->shift = clks->div_offset;
  95
  96         if (clks->bypass_reg)
  97                 socfpga_clk->bypass_reg = regbase + clks->bypass_reg;
  98         else
  99                 socfpga_clk->bypass_reg = NULL;
 100         socfpga_clk->bypass_shift = clks->bypass_shift;
 101
 102         if (streq(clks->name, "cs_pdbg_clk"))
 103                 init.ops = &dbgclk_ops;
 104         else
 105                 init.ops = &gateclk_ops;
 106
 107         init.name = clks->name;
 108         init.flags = clks->flags;
 109
 110         init.num_parents = clks->num_parents;
 111         init.parent_names = parent_name ? &parent_name : NULL;
 112         if (init.parent_names == NULL)
 113                 init.parent_data = clks->parent_data;
 114         socfpga_clk->hw.hw.init = &init;
 115
 116         hw_clk = &socfpga_clk->hw.hw;
 117
 118         ret = clk_hw_register(NULL, &socfpga_clk->hw.hw);
 119         if (ret) {
 120                 kfree(socfpga_clk);
 121                 return ERR_PTR(ret);
 122         }
 123         return hw_clk;
 124 }