arch/blackfin/mach-common/clocks-init.c

   1 /*
   2  * arch/blackfin/mach-common/clocks-init.c - reprogram clocks / memory
   3  *
   4  * Copyright 2004-2008 Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2 or later.
   7  */
   8
   9 #include <linux/linkage.h>
  10 #include <linux/init.h>
  11 #include <asm/blackfin.h>
  12
  13 #include <asm/dma.h>
  14 #include <asm/clocks.h>
  15 #include <asm/mem_init.h>
  16
  17 #define SDGCTL_WIDTH (1 << 31)  /* SDRAM external data path width */
  18 #define PLL_CTL_VAL \
  19         (((CONFIG_VCO_MULT & 63) << 9) | CLKIN_HALF | \
  20          (PLL_BYPASS << 8) | (ANOMALY_05000305 ? 0 : 0x8000))
  21
  22 __attribute__((l1_text))
  23 static void do_sync(void)
  24 {
  25         __builtin_bfin_ssync();
  26 }
  27
  28 __attribute__((l1_text))
  29 void init_clocks(void)
  30 {
  31         /* Kill any active DMAs as they may trigger external memory accesses
  32          * in the middle of reprogramming things, and that'll screw us up.
  33          * For example, any automatic DMAs left by U-Boot for splash screens.
  34          */
  35         size_t i;
  36         for (i = 0; i < MAX_DMA_CHANNELS; ++i) {
  37                 struct dma_register *dma = dma_io_base_addr[i];
  38                 dma->cfg = 0;
  39         }
  40
  41         do_sync();
  42
  43 #ifdef SIC_IWR0
  44         bfin_write_SIC_IWR0(IWR_ENABLE(0));
  45 # ifdef SIC_IWR1
  46         /* BF52x system reset does not properly reset SIC_IWR1 which
  47          * will screw up the bootrom as it relies on MDMA0/1 waking it
  48          * up from IDLE instructions.  See this report for more info:
  49          * http://blackfin.uclinux.org/gf/tracker/4323
  50          */
  51         if (ANOMALY_05000435)
  52                 bfin_write_SIC_IWR1(IWR_ENABLE(10) | IWR_ENABLE(11));
  53         else
  54                 bfin_write_SIC_IWR1(IWR_DISABLE_ALL);
  55 # endif
  56 # ifdef SIC_IWR2
  57         bfin_write_SIC_IWR2(IWR_DISABLE_ALL);
  58 # endif
  59 #else
  60         bfin_write_SIC_IWR(IWR_ENABLE(0));
  61 #endif
  62         do_sync();
  63 #ifdef EBIU_SDGCTL
  64         bfin_write_EBIU_SDGCTL(bfin_read_EBIU_SDGCTL() | SRFS);
  65         do_sync();
  66 #endif
  67
  68 #ifdef CLKBUFOE
  69         bfin_write16(VR_CTL, bfin_read_VR_CTL() | CLKBUFOE);
  70         do_sync();
  71         __asm__ __volatile__("IDLE;");
  72 #endif
  73         bfin_write_PLL_LOCKCNT(0x300);
  74         do_sync();
  75         /* We always write PLL_CTL thus avoiding Anomaly 05000242 */
  76         bfin_write16(PLL_CTL, PLL_CTL_VAL);
  77         __asm__ __volatile__("IDLE;");
  78         bfin_write_PLL_DIV(CONFIG_CCLK_ACT_DIV | CONFIG_SCLK_DIV);
  79 #ifdef EBIU_SDGCTL
  80         bfin_write_EBIU_SDRRC(mem_SDRRC);
  81         bfin_write_EBIU_SDGCTL((bfin_read_EBIU_SDGCTL() & SDGCTL_WIDTH) | mem_SDGCTL);
  82 #else
  83         bfin_write_EBIU_RSTCTL(bfin_read_EBIU_RSTCTL() & ~(SRREQ));
  84         do_sync();
  85         bfin_write_EBIU_RSTCTL(bfin_read_EBIU_RSTCTL() | 0x1);
  86         bfin_write_EBIU_DDRCTL0(mem_DDRCTL0);
  87         bfin_write_EBIU_DDRCTL1(mem_DDRCTL1);
  88         bfin_write_EBIU_DDRCTL2(mem_DDRCTL2);
  89 #ifdef CONFIG_MEM_EBIU_DDRQUE
  90         bfin_write_EBIU_DDRQUE(CONFIG_MEM_EBIU_DDRQUE);
  91 #endif
  92 #endif
  93         do_sync();
  94         bfin_read16(0);
  95 }