arch/arm/cpu/at91-common/spl_at91.c

   1 /*
   2  * (C) Copyright 2014 DENX Software Engineering
   3  *     Heiko Schocher <hs@denx.de>
   4  *
   5  * Based on:
   6  * Copyright (C) 2013 Atmel Corporation
   7  *                    Bo Shen <voice.shen@atmel.com>
   8  *
   9  * SPDX-License-Identifier:     GPL-2.0+
  10  */
  11
  12 #include <common.h>
  13 #include <asm/io.h>
  14 #include <asm/arch/at91_common.h>
  15 #include <asm/arch/at91sam9_matrix.h>
  16 #include <asm/arch/at91_pit.h>
  17 #include <asm/arch/at91_pmc.h>
  18 #include <asm/arch/at91_rstc.h>
  19 #include <asm/arch/at91_wdt.h>
  20 #include <asm/arch/clk.h>
  21 #include <spl.h>
  22
  23 DECLARE_GLOBAL_DATA_PTR;
  24
  25 static void enable_ext_reset(void)
  26 {
  27         struct at91_rstc *rstc = (struct at91_rstc *)ATMEL_BASE_RSTC;
  28
  29         writel(AT91_RSTC_KEY | AT91_RSTC_MR_URSTEN, &rstc->mr);
  30 }
  31
  32 void lowlevel_clock_init(void)
  33 {
  34         struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
  35
  36         if (!(readl(&pmc->sr) & AT91_PMC_MOSCS)) {
  37                 /* Enable Main Oscillator */
  38                 writel(AT91_PMC_MOSCS | (0x40 << 8), &pmc->mor);
  39
  40                 /* Wait until Main Oscillator is stable */
  41                 while (!(readl(&pmc->sr) & AT91_PMC_MOSCS))
  42                         ;
  43         }
  44
  45         /* After stabilization, switch to Main Oscillator */
  46         if ((readl(&pmc->mckr) & AT91_PMC_CSS) == AT91_PMC_CSS_SLOW) {
  47                 unsigned long tmp;
  48
  49                 tmp = readl(&pmc->mckr);
  50                 tmp &= ~AT91_PMC_CSS;
  51                 tmp |= AT91_PMC_CSS_MAIN;
  52                 writel(tmp, &pmc->mckr);
  53                 while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY))
  54                         ;
  55
  56                 tmp &= ~AT91_PMC_PRES;
  57                 tmp |= AT91_PMC_PRES_1;
  58                 writel(tmp, &pmc->mckr);
  59                 while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY))
  60                         ;
  61         }
  62
  63         return;
  64 }
  65
  66 void __weak matrix_init(void)
  67 {
  68 }
  69
  70 void __weak at91_spl_board_init(void)
  71 {
  72 }
  73
  74 void spl_board_init(void)
  75 {
  76         struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
  77
  78         lowlevel_clock_init();
  79         at91_disable_wdt();
  80
  81         /*
  82          * At this stage the main oscillator is supposed to be enabled
  83          * PCK = MCK = MOSC
  84          */
  85         writel(0x00, &pmc->pllicpr);
  86
  87         /* Configure PLLA = MOSC * (PLL_MULA + 1) / PLL_DIVA */
  88         at91_plla_init(CONFIG_SYS_AT91_PLLA);
  89
  90         /* PCK = PLLA = 2 * MCK */
  91         at91_mck_init(CONFIG_SYS_MCKR);
  92
  93         /* Switch MCK on PLLA output */
  94         at91_mck_init(CONFIG_SYS_MCKR_CSS);
  95
  96 #if defined(CONFIG_SYS_AT91_PLLB)
  97         /* Configure PLLB */
  98         at91_pllb_init(CONFIG_SYS_AT91_PLLB);
  99 #endif
 100
 101         /* Enable External Reset */
 102         enable_ext_reset();
 103
 104         /* Initialize matrix */
 105         matrix_init();
 106
 107         gd->arch.mck_rate_hz = CONFIG_SYS_MASTER_CLOCK;
 108         /*
 109          * init timer long enough for using in spl.
 110          */
 111         timer_init();
 112
 113         /* enable clocks for all PIOs */
 114         at91_periph_clk_enable(ATMEL_ID_PIOA);
 115         at91_periph_clk_enable(ATMEL_ID_PIOB);
 116         at91_periph_clk_enable(ATMEL_ID_PIOC);
 117         /* init console */
 118         at91_seriald_hw_init();
 119         preloader_console_init();
 120
 121         mem_init();
 122
 123         at91_spl_board_init();
 124 }