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

   1 // SPDX-License-Identifier:     GPL-2.0
   2 /*
   3  * Copyright (C) 2017, Intel Corporation
   4  */
   5 #include <linux/slab.h>
   6 #include <linux/clk-provider.h>
   7
   8 #include "stratix10-clk.h"
   9 #include "clk.h"
  10
  11 /* Clock Manager offsets */
  12 #define CLK_MGR_PLL_CLK_SRC_SHIFT       16
  13 #define CLK_MGR_PLL_CLK_SRC_MASK        0x3
  14
  15 /* PLL Clock enable bits */
  16 #define SOCFPGA_PLL_POWER               0
  17 #define SOCFPGA_PLL_RESET_MASK          0x2
  18 #define SOCFPGA_PLL_REFDIV_MASK         0x00003F00
  19 #define SOCFPGA_PLL_REFDIV_SHIFT        8
  20 #define SOCFPGA_PLL_MDIV_MASK           0xFF000000
  21 #define SOCFPGA_PLL_MDIV_SHIFT          24
  22 #define SWCTRLBTCLKSEL_MASK             0x200
  23 #define SWCTRLBTCLKSEL_SHIFT            9
  24
  25 #define SOCFPGA_BOOT_CLK                "boot_clk"
  26
  27 #define to_socfpga_clk(p) container_of(p, struct socfpga_pll, hw.hw)
  28
  29 static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
  30                                          unsigned long parent_rate)
  31 {
  32         struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
  33         unsigned long mdiv;
  34         unsigned long refdiv;
  35         unsigned long reg;
  36         unsigned long long vco_freq;
  37
  38         /* read VCO1 reg for numerator and denominator */
  39         reg = readl(socfpgaclk->hw.reg);
  40         refdiv = (reg & SOCFPGA_PLL_REFDIV_MASK) >> SOCFPGA_PLL_REFDIV_SHIFT;
  41         vco_freq = (unsigned long long)parent_rate / refdiv;
  42
  43         /* Read mdiv and fdiv from the fdbck register */
  44         reg = readl(socfpgaclk->hw.reg + 0x4);
  45         mdiv = (reg & SOCFPGA_PLL_MDIV_MASK) >> SOCFPGA_PLL_MDIV_SHIFT;
  46         vco_freq = (unsigned long long)parent_rate * (mdiv + 6);
  47
  48         return (unsigned long)vco_freq;
  49 }
  50
  51 static unsigned long clk_boot_clk_recalc_rate(struct clk_hw *hwclk,
  52                                          unsigned long parent_rate)
  53 {
  54         struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
  55         u32 div = 1;
  56
  57         div = ((readl(socfpgaclk->hw.reg) &
  58                 SWCTRLBTCLKSEL_MASK) >>
  59                 SWCTRLBTCLKSEL_SHIFT);
  60         div += 1;
  61         return parent_rate /= div;
  62 }
  63
  64
  65 static u8 clk_pll_get_parent(struct clk_hw *hwclk)
  66 {
  67         struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
  68         u32 pll_src;
  69
  70         pll_src = readl(socfpgaclk->hw.reg);
  71         return (pll_src >> CLK_MGR_PLL_CLK_SRC_SHIFT) &
  72                 CLK_MGR_PLL_CLK_SRC_MASK;
  73 }
  74
  75 static u8 clk_boot_get_parent(struct clk_hw *hwclk)
  76 {
  77         struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
  78         u32 pll_src;
  79
  80         pll_src = readl(socfpgaclk->hw.reg);
  81         return (pll_src >> SWCTRLBTCLKSEL_SHIFT) &
  82                 SWCTRLBTCLKSEL_MASK;
  83 }
  84
  85 static int clk_pll_prepare(struct clk_hw *hwclk)
  86 {
  87         struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
  88         u32 reg;
  89
  90         /* Bring PLL out of reset */
  91         reg = readl(socfpgaclk->hw.reg);
  92         reg |= SOCFPGA_PLL_RESET_MASK;
  93         writel(reg, socfpgaclk->hw.reg);
  94
  95         return 0;
  96 }
  97
  98 static struct clk_ops clk_pll_ops = {
  99         .recalc_rate = clk_pll_recalc_rate,
 100         .get_parent = clk_pll_get_parent,
 101         .prepare = clk_pll_prepare,
 102 };
 103
 104 static struct clk_ops clk_boot_ops = {
 105         .recalc_rate = clk_boot_clk_recalc_rate,
 106         .get_parent = clk_boot_get_parent,
 107         .prepare = clk_pll_prepare,
 108 };
 109
 110 struct clk *s10_register_pll(const char *name, const char * const *parent_names,
 111                                     u8 num_parents, unsigned long flags,
 112                                     void __iomem *reg, unsigned long offset)
 113 {
 114         struct clk *clk;
 115         struct socfpga_pll *pll_clk;
 116         struct clk_init_data init;
 117
 118         pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
 119         if (WARN_ON(!pll_clk))
 120                 return NULL;
 121
 122         pll_clk->hw.reg = reg + offset;
 123
 124         if (streq(name, SOCFPGA_BOOT_CLK))
 125                 init.ops = &clk_boot_ops;
 126         else
 127                 init.ops = &clk_pll_ops;
 128
 129         init.name = name;
 130         init.flags = flags;
 131
 132         init.num_parents = num_parents;
 133         init.parent_names = parent_names;
 134         pll_clk->hw.hw.init = &init;
 135
 136         pll_clk->hw.bit_idx = SOCFPGA_PLL_POWER;
 137         clk_pll_ops.enable = clk_gate_ops.enable;
 138         clk_pll_ops.disable = clk_gate_ops.disable;
 139
 140         clk = clk_register(NULL, &pll_clk->hw.hw);
 141         if (WARN_ON(IS_ERR(clk))) {
 142                 kfree(pll_clk);
 143                 return NULL;
 144         }
 145         return clk;
 146 }