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

   1 /*
   2  * Copyright (C) 2013 Atmel Corporation
   3  *                    Bo Shen <voice.shen@atmel.com>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <asm/io.h>
  10 #include <asm/arch/at91_common.h>
  11 #include <asm/arch/at91_pit.h>
  12 #include <asm/arch/at91_pmc.h>
  13 #include <asm/arch/at91_rstc.h>
  14 #include <asm/arch/at91_wdt.h>
  15 #include <asm/arch/clk.h>
  16 #include <spl.h>
  17
  18 DECLARE_GLOBAL_DATA_PTR;
  19
  20 static void switch_to_main_crystal_osc(void)
  21 {
  22         struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
  23         u32 tmp;
  24
  25         tmp = readl(&pmc->mor);
  26         tmp &= ~AT91_PMC_MOR_OSCOUNT(0xff);
  27         tmp &= ~AT91_PMC_MOR_KEY(0xff);
  28         tmp |= AT91_PMC_MOR_MOSCEN;
  29         tmp |= AT91_PMC_MOR_OSCOUNT(8);
  30         tmp |= AT91_PMC_MOR_KEY(0x37);
  31         writel(tmp, &pmc->mor);
  32         while (!(readl(&pmc->sr) & AT91_PMC_IXR_MOSCS))
  33                 ;
  34
  35         tmp = readl(&pmc->mor);
  36         tmp &= ~AT91_PMC_MOR_OSCBYPASS;
  37         tmp &= ~AT91_PMC_MOR_KEY(0xff);
  38         tmp |= AT91_PMC_MOR_KEY(0x37);
  39         writel(tmp, &pmc->mor);
  40
  41         tmp = readl(&pmc->mor);
  42         tmp |= AT91_PMC_MOR_MOSCSEL;
  43         tmp &= ~AT91_PMC_MOR_KEY(0xff);
  44         tmp |= AT91_PMC_MOR_KEY(0x37);
  45         writel(tmp, &pmc->mor);
  46
  47         while (!(readl(&pmc->sr) & AT91_PMC_IXR_MOSCSELS))
  48                 ;
  49
  50         /* Wait until MAINRDY field is set to make sure main clock is stable */
  51         while (!(readl(&pmc->mcfr) & AT91_PMC_MAINRDY))
  52                 ;
  53
  54         tmp = readl(&pmc->mor);
  55         tmp &= ~AT91_PMC_MOR_MOSCRCEN;
  56         tmp &= ~AT91_PMC_MOR_KEY(0xff);
  57         tmp |= AT91_PMC_MOR_KEY(0x37);
  58         writel(tmp, &pmc->mor);
  59 }
  60
  61 void s_init(void)
  62 {
  63         switch_to_main_crystal_osc();
  64
  65         /* disable watchdog */
  66         at91_disable_wdt();
  67
  68         /* PMC configuration */
  69         at91_pmc_init();
  70
  71         at91_clock_init(CONFIG_SYS_AT91_MAIN_CLOCK);
  72
  73         timer_init();
  74
  75         board_early_init_f();
  76
  77         preloader_console_init();
  78
  79         mem_init();
  80 }