arch/mips/pic32/pic32mzda/early_clk.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Joshua Henderson <joshua.henderson@microchip.com>
   4  * Copyright (C) 2015 Microchip Technology Inc.  All rights reserved.
   5  */
   6 #include <asm/mach-pic32/pic32.h>
   7
   8 #include "pic32mzda.h"
   9
  10 /* Oscillators, PLL & clocks */
  11 #define ICLK_MASK       0x00000080
  12 #define PLLDIV_MASK     0x00000007
  13 #define CUROSC_MASK     0x00000007
  14 #define PLLMUL_MASK     0x0000007F
  15 #define PB_MASK         0x00000007
  16 #define FRC1            0
  17 #define FRC2            7
  18 #define SPLL            1
  19 #define POSC            2
  20 #define FRC_CLK         8000000
  21
  22 #define PIC32_POSC_FREQ 24000000
  23
  24 #define OSCCON          0x0000
  25 #define SPLLCON         0x0020
  26 #define PB1DIV          0x0140
  27
  28 u32 pic32_get_sysclk(void)
  29 {
  30         u32 osc_freq = 0;
  31         u32 pllclk;
  32         u32 frcdivn;
  33         u32 osccon;
  34         u32 spllcon;
  35         int curr_osc;
  36
  37         u32 plliclk;
  38         u32 pllidiv;
  39         u32 pllodiv;
  40         u32 pllmult;
  41         u32 frcdiv;
  42
  43         void __iomem *osc_base = ioremap(PIC32_BASE_OSC, 0x200);
  44
  45         osccon = __raw_readl(osc_base + OSCCON);
  46         spllcon = __raw_readl(osc_base + SPLLCON);
  47
  48         plliclk = (spllcon & ICLK_MASK);
  49         pllidiv = ((spllcon >> 8) & PLLDIV_MASK) + 1;
  50         pllodiv = ((spllcon >> 24) & PLLDIV_MASK);
  51         pllmult = ((spllcon >> 16) & PLLMUL_MASK) + 1;
  52         frcdiv = ((osccon >> 24) & PLLDIV_MASK);
  53
  54         pllclk = plliclk ? FRC_CLK : PIC32_POSC_FREQ;
  55         frcdivn = ((1 << frcdiv) + 1) + (128 * (frcdiv == 7));
  56
  57         if (pllodiv < 2)
  58                 pllodiv = 2;
  59         else if (pllodiv < 5)
  60                 pllodiv = (1 << pllodiv);
  61         else
  62                 pllodiv = 32;
  63
  64         curr_osc = (int)((osccon >> 12) & CUROSC_MASK);
  65
  66         switch (curr_osc) {
  67         case FRC1:
  68         case FRC2:
  69                 osc_freq = FRC_CLK / frcdivn;
  70                 break;
  71         case SPLL:
  72                 osc_freq = ((pllclk / pllidiv) * pllmult) / pllodiv;
  73                 break;
  74         case POSC:
  75                 osc_freq = PIC32_POSC_FREQ;
  76                 break;
  77         default:
  78                 break;
  79         }
  80
  81         iounmap(osc_base);
  82
  83         return osc_freq;
  84 }
  85
  86 u32 pic32_get_pbclk(int bus)
  87 {
  88         u32 clk_freq;
  89         void __iomem *osc_base = ioremap(PIC32_BASE_OSC, 0x200);
  90         u32 pbxdiv = PB1DIV + ((bus - 1) * 0x10);
  91         u32 pbdiv = (__raw_readl(osc_base + pbxdiv) & PB_MASK) + 1;
  92
  93         iounmap(osc_base);
  94
  95         clk_freq = pic32_get_sysclk();
  96
  97         return clk_freq / pbdiv;
  98 }