Factor out SC520 sub-features
authorGraeme Russ <graeme.russ@gmail.com>
Tue, 24 Feb 2009 10:14:32 +0000 (21:14 +1100)
committerWolfgang Denk <wd@denx.de>
Fri, 20 Mar 2009 21:39:13 +0000 (22:39 +0100)
Moved sub-features of the SC520 code which is currently selectively compiled
using #ifdef out of sc520.c into individual files selectively compiled via
the makefile

Signed-off-by: Graeme Russ <graeme.russ at gmail.com>
cpu/i386/sc520/Makefile
cpu/i386/sc520/sc520.c
cpu/i386/sc520/sc520_pci.c [new file with mode: 0644]
cpu/i386/sc520/sc520_ssi.c [new file with mode: 0644]
cpu/i386/sc520/sc520_timer.c [new file with mode: 0644]

index ddfec23f601590fd46a4575ed99a283e52686c8b..87835b2c20ddea1efbb251f3069e4549e2c6bff2 100644 (file)
@@ -32,6 +32,10 @@ include $(TOPDIR)/config.mk
 LIB    := $(obj)lib$(SOC).a
 
 COBJS-$(CONFIG_SYS_SC520) += sc520.o
+COBJS-$(CONFIG_SYS_SC520_SSI) += sc520_ssi.o
+COBJS-$(CONFIG_SYS_SC520_TIMER) += sc520_timer.o
+COBJS-$(CONFIG_PCI) += sc520_pci.o
+
 SOBJS-$(CONFIG_SYS_SC520) += sc520_asm.o
 
 SRCS   := $(SOBJS-y:.o=.S) $(COBJS-y:.o=.c)
index 2ac3fd40cdf083024ea2501d1aac8533444e4c1c..ae3b50007f22baec2b852e7759c03797affe5b60 100644 (file)
 /* stuff specific for the sc520,
  * but idependent of implementation */
 
-#include <config.h>
 #include <common.h>
-#include <config.h>
-#include <pci.h>
-#ifdef CONFIG_SYS_SC520_SSI
-#include <asm/ic/ssi.h>
-#endif
 #include <asm/io.h>
-#include <asm/pci.h>
 #include <asm/ic/sc520.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -50,13 +43,6 @@ DECLARE_GLOBAL_DATA_PTR;
  *
  * void init_sc520(void)
  * unsigned long init_sc520_dram(void)
- * void pci_sc520_init(struct pci_controller *hose)
- *
- * void reset_timer(void)
- * ulong get_timer(ulong base)
- * void set_timer(ulong t)
- * void udelay(unsigned long usec)
- *
  */
 
 static u32 mmcr_base= 0xfffef000;
@@ -241,269 +227,6 @@ unsigned long init_sc520_dram(void)
        return dram_present;
 }
 
-
-#ifdef CONFIG_PCI
-
-
-static struct {
-       u8 priority;
-       u16 level_reg;
-       u8 level_bit;
-} sc520_irq[] = {
-       { SC520_IRQ0,  SC520_MPICMODE,  0x01 },
-       { SC520_IRQ1,  SC520_MPICMODE,  0x02 },
-       { SC520_IRQ2,  SC520_SL1PICMODE, 0x02 },
-       { SC520_IRQ3,  SC520_MPICMODE,  0x08 },
-       { SC520_IRQ4,  SC520_MPICMODE,  0x10 },
-       { SC520_IRQ5,  SC520_MPICMODE,  0x20 },
-       { SC520_IRQ6,  SC520_MPICMODE,  0x40 },
-       { SC520_IRQ7,  SC520_MPICMODE,  0x80 },
-
-       { SC520_IRQ8,  SC520_SL1PICMODE, 0x01 },
-       { SC520_IRQ9,  SC520_SL1PICMODE, 0x02 },
-       { SC520_IRQ10, SC520_SL1PICMODE, 0x04 },
-       { SC520_IRQ11, SC520_SL1PICMODE, 0x08 },
-       { SC520_IRQ12, SC520_SL1PICMODE, 0x10 },
-       { SC520_IRQ13, SC520_SL1PICMODE, 0x20 },
-       { SC520_IRQ14, SC520_SL1PICMODE, 0x40 },
-       { SC520_IRQ15, SC520_SL1PICMODE, 0x80 }
-};
-
-
-/* The interrupt used for PCI INTA-INTD  */
-int sc520_pci_ints[15] = {
-       -1, -1, -1, -1, -1, -1, -1, -1,
-               -1, -1, -1, -1, -1, -1, -1
-};
-
-/* utility function to configure a pci interrupt */
-int pci_sc520_set_irq(int pci_pin, int irq)
-{
-       int i;
-
-# if 1
-       printf("set_irq(): map INT%c to IRQ%d\n", pci_pin + 'A', irq);
-#endif
-       if (irq < 0 || irq > 15) {
-               return -1; /* illegal irq */
-       }
-
-       if (pci_pin < 0 || pci_pin > 15) {
-               return -1; /* illegal pci int pin */
-       }
-
-       /* first disable any non-pci interrupt source that use
-        * this level */
-       for (i=SC520_GPTMR0MAP;i<=SC520_GP10IMAP;i++) {
-               if (i>=SC520_PCIINTAMAP&&i<=SC520_PCIINTDMAP) {
-                       continue;
-               }
-               if (read_mmcr_byte(i) == sc520_irq[irq].priority) {
-                       write_mmcr_byte(i, SC520_IRQ_DISABLED);
-               }
-       }
-
-       /* Set the trigger to level */
-       write_mmcr_byte(sc520_irq[irq].level_reg,
-                       read_mmcr_byte(sc520_irq[irq].level_reg) | sc520_irq[irq].level_bit);
-
-
-       if (pci_pin < 4) {
-               /* PCI INTA-INTD */
-               /* route the interrupt */
-               write_mmcr_byte(SC520_PCIINTAMAP + pci_pin, sc520_irq[irq].priority);
-
-
-       } else {
-               /* GPIRQ0-GPIRQ10 used for additional PCI INTS */
-               write_mmcr_byte(SC520_GP0IMAP + pci_pin - 4, sc520_irq[irq].priority);
-
-               /* also set the polarity in this case */
-               write_mmcr_word(SC520_INTPINPOL,
-                               read_mmcr_word(SC520_INTPINPOL) | (1 << (pci_pin-4)));
-
-       }
-
-       /* register the pin */
-       sc520_pci_ints[pci_pin] = irq;
-
-
-       return 0; /* OK */
-}
-
-void pci_sc520_init(struct pci_controller *hose)
-{
-       hose->first_busno = 0;
-       hose->last_busno = 0xff;
-
-       /* System memory space */
-       pci_set_region(hose->regions + 0,
-                      SC520_PCI_MEMORY_BUS,
-                      SC520_PCI_MEMORY_PHYS,
-                      SC520_PCI_MEMORY_SIZE,
-                      PCI_REGION_MEM | PCI_REGION_SYS_MEMORY);
-
-       /* PCI memory space */
-       pci_set_region(hose->regions + 1,
-                      SC520_PCI_MEM_BUS,
-                      SC520_PCI_MEM_PHYS,
-                      SC520_PCI_MEM_SIZE,
-                      PCI_REGION_MEM);
-
-       /* ISA/PCI memory space */
-       pci_set_region(hose->regions + 2,
-                      SC520_ISA_MEM_BUS,
-                      SC520_ISA_MEM_PHYS,
-                      SC520_ISA_MEM_SIZE,
-                      PCI_REGION_MEM);
-
-       /* PCI I/O space */
-       pci_set_region(hose->regions + 3,
-                      SC520_PCI_IO_BUS,
-                      SC520_PCI_IO_PHYS,
-                      SC520_PCI_IO_SIZE,
-                      PCI_REGION_IO);
-
-       /* ISA/PCI I/O space */
-       pci_set_region(hose->regions + 4,
-                      SC520_ISA_IO_BUS,
-                      SC520_ISA_IO_PHYS,
-                      SC520_ISA_IO_SIZE,
-                      PCI_REGION_IO);
-
-       hose->region_count = 5;
-
-       pci_setup_type1(hose,
-                       SC520_REG_ADDR,
-                       SC520_REG_DATA);
-
-       pci_register_hose(hose);
-
-       hose->last_busno = pci_hose_scan(hose);
-
-       /* enable target memory acceses on host brige */
-       pci_write_config_word(0, PCI_COMMAND,
-                             PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
-
-}
-
-
-#endif
-
-#ifdef CONFIG_SYS_SC520_TIMER
-
-
-void reset_timer(void)
-{
-       write_mmcr_word(SC520_GPTMR0CNT, 0);
-       write_mmcr_word(SC520_GPTMR0CTL, 0x6001);
-
-}
-
-ulong get_timer(ulong base)
-{
-       /* fixme: 30 or 33 */
-       return  read_mmcr_word(SC520_GPTMR0CNT) / 33;
-}
-
-void set_timer(ulong t)
-{
-       /* FixMe: use two cascade coupled timers */
-       write_mmcr_word(SC520_GPTMR0CTL, 0x4001);
-       write_mmcr_word(SC520_GPTMR0CNT, t*33);
-       write_mmcr_word(SC520_GPTMR0CTL, 0x6001);
-}
-
-
-void udelay(unsigned long usec)
-{
-       int m=0;
-       long u;
-
-       read_mmcr_word(SC520_SWTMRMILLI);
-       read_mmcr_word(SC520_SWTMRMICRO);
-
-#if 0
-       /* do not enable this line, udelay is used in the serial driver -> recursion */
-       printf("udelay: %ld m.u %d.%d  tm.tu %d.%d\n", usec, m, u, tm, tu);
-#endif
-       while (1) {
-
-               m += read_mmcr_word(SC520_SWTMRMILLI);
-               u = read_mmcr_word(SC520_SWTMRMICRO) + (m * 1000);
-
-               if (usec <= u) {
-                       break;
-               }
-       }
-}
-
-#endif
-
-int ssi_set_interface(int freq, int lsb_first, int inv_clock, int inv_phase)
-{
-       u8 temp=0;
-
-       if (freq >= 8192) {
-               temp |= CTL_CLK_SEL_4;
-       } else if (freq >= 4096) {
-               temp |= CTL_CLK_SEL_8;
-       } else if (freq >= 2048) {
-               temp |= CTL_CLK_SEL_16;
-       } else if (freq >= 1024) {
-               temp |= CTL_CLK_SEL_32;
-       } else if (freq >= 512) {
-               temp |= CTL_CLK_SEL_64;
-       } else if (freq >= 256) {
-               temp |= CTL_CLK_SEL_128;
-       } else if (freq >= 128) {
-               temp |= CTL_CLK_SEL_256;
-       } else {
-               temp |= CTL_CLK_SEL_512;
-       }
-
-       if (!lsb_first) {
-               temp |= MSBF_ENB;
-       }
-
-       if (inv_clock) {
-               temp |= CLK_INV_ENB;
-       }
-
-       if (inv_phase) {
-               temp |= PHS_INV_ENB;
-       }
-
-       write_mmcr_byte(SC520_SSICTL, temp);
-
-       return 0;
-}
-
-u8 ssi_txrx_byte(u8 data)
-{
-       write_mmcr_byte(SC520_SSIXMIT, data);
-       while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
-       write_mmcr_byte(SC520_SSICMD, SSICMD_CMD_SEL_XMITRCV);
-       while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
-       return read_mmcr_byte(SC520_SSIRCV);
-}
-
-
-void ssi_tx_byte(u8 data)
-{
-       write_mmcr_byte(SC520_SSIXMIT, data);
-       while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
-       write_mmcr_byte(SC520_SSICMD, SSICMD_CMD_SEL_XMIT);
-}
-
-u8 ssi_rx_byte(void)
-{
-       while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
-       write_mmcr_byte(SC520_SSICMD, SSICMD_CMD_SEL_RCV);
-       while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
-       return read_mmcr_byte(SC520_SSIRCV);
-}
-
 #ifdef CONFIG_SYS_SC520_RESET
 void reset_cpu(ulong addr)
 {
diff --git a/cpu/i386/sc520/sc520_pci.c b/cpu/i386/sc520/sc520_pci.c
new file mode 100644 (file)
index 0000000..38b837e
--- /dev/null
@@ -0,0 +1,171 @@
+/*
+ * (C) Copyright 2002
+ * Daniel Engström, Omicron Ceti AB <daniel@omicron.se>.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/* stuff specific for the sc520, but independent of implementation */
+
+#include <common.h>
+#include <pci.h>
+#include <asm/pci.h>
+#include <asm/ic/sc520.h>
+
+static struct {
+       u8 priority;
+       u16 level_reg;
+       u8 level_bit;
+} sc520_irq[] = {
+       { SC520_IRQ0,  SC520_MPICMODE,  0x01 },
+       { SC520_IRQ1,  SC520_MPICMODE,  0x02 },
+       { SC520_IRQ2,  SC520_SL1PICMODE, 0x02 },
+       { SC520_IRQ3,  SC520_MPICMODE,  0x08 },
+       { SC520_IRQ4,  SC520_MPICMODE,  0x10 },
+       { SC520_IRQ5,  SC520_MPICMODE,  0x20 },
+       { SC520_IRQ6,  SC520_MPICMODE,  0x40 },
+       { SC520_IRQ7,  SC520_MPICMODE,  0x80 },
+
+       { SC520_IRQ8,  SC520_SL1PICMODE, 0x01 },
+       { SC520_IRQ9,  SC520_SL1PICMODE, 0x02 },
+       { SC520_IRQ10, SC520_SL1PICMODE, 0x04 },
+       { SC520_IRQ11, SC520_SL1PICMODE, 0x08 },
+       { SC520_IRQ12, SC520_SL1PICMODE, 0x10 },
+       { SC520_IRQ13, SC520_SL1PICMODE, 0x20 },
+       { SC520_IRQ14, SC520_SL1PICMODE, 0x40 },
+       { SC520_IRQ15, SC520_SL1PICMODE, 0x80 }
+};
+
+
+/* The interrupt used for PCI INTA-INTD  */
+int sc520_pci_ints[15] = {
+       -1, -1, -1, -1, -1, -1, -1, -1,
+               -1, -1, -1, -1, -1, -1, -1
+};
+
+/* utility function to configure a pci interrupt */
+int pci_sc520_set_irq(int pci_pin, int irq)
+{
+       int i;
+
+# if 1
+       printf("set_irq(): map INT%c to IRQ%d\n", pci_pin + 'A', irq);
+#endif
+       if (irq < 0 || irq > 15) {
+               return -1; /* illegal irq */
+       }
+
+       if (pci_pin < 0 || pci_pin > 15) {
+               return -1; /* illegal pci int pin */
+       }
+
+       /* first disable any non-pci interrupt source that use
+        * this level */
+       for (i=SC520_GPTMR0MAP;i<=SC520_GP10IMAP;i++) {
+               if (i>=SC520_PCIINTAMAP&&i<=SC520_PCIINTDMAP) {
+                       continue;
+               }
+               if (read_mmcr_byte(i) == sc520_irq[irq].priority) {
+                       write_mmcr_byte(i, SC520_IRQ_DISABLED);
+               }
+       }
+
+       /* Set the trigger to level */
+       write_mmcr_byte(sc520_irq[irq].level_reg,
+                       read_mmcr_byte(sc520_irq[irq].level_reg) | sc520_irq[irq].level_bit);
+
+
+       if (pci_pin < 4) {
+               /* PCI INTA-INTD */
+               /* route the interrupt */
+               write_mmcr_byte(SC520_PCIINTAMAP + pci_pin, sc520_irq[irq].priority);
+
+
+       } else {
+               /* GPIRQ0-GPIRQ10 used for additional PCI INTS */
+               write_mmcr_byte(SC520_GP0IMAP + pci_pin - 4, sc520_irq[irq].priority);
+
+               /* also set the polarity in this case */
+               write_mmcr_word(SC520_INTPINPOL,
+                               read_mmcr_word(SC520_INTPINPOL) | (1 << (pci_pin-4)));
+
+       }
+
+       /* register the pin */
+       sc520_pci_ints[pci_pin] = irq;
+
+
+       return 0; /* OK */
+}
+
+void pci_sc520_init(struct pci_controller *hose)
+{
+       hose->first_busno = 0;
+       hose->last_busno = 0xff;
+
+       /* System memory space */
+       pci_set_region(hose->regions + 0,
+                      SC520_PCI_MEMORY_BUS,
+                      SC520_PCI_MEMORY_PHYS,
+                      SC520_PCI_MEMORY_SIZE,
+                      PCI_REGION_MEM | PCI_REGION_MEMORY);
+
+       /* PCI memory space */
+       pci_set_region(hose->regions + 1,
+                      SC520_PCI_MEM_BUS,
+                      SC520_PCI_MEM_PHYS,
+                      SC520_PCI_MEM_SIZE,
+                      PCI_REGION_MEM);
+
+       /* ISA/PCI memory space */
+       pci_set_region(hose->regions + 2,
+                      SC520_ISA_MEM_BUS,
+                      SC520_ISA_MEM_PHYS,
+                      SC520_ISA_MEM_SIZE,
+                      PCI_REGION_MEM);
+
+       /* PCI I/O space */
+       pci_set_region(hose->regions + 3,
+                      SC520_PCI_IO_BUS,
+                      SC520_PCI_IO_PHYS,
+                      SC520_PCI_IO_SIZE,
+                      PCI_REGION_IO);
+
+       /* ISA/PCI I/O space */
+       pci_set_region(hose->regions + 4,
+                      SC520_ISA_IO_BUS,
+                      SC520_ISA_IO_PHYS,
+                      SC520_ISA_IO_SIZE,
+                      PCI_REGION_IO);
+
+       hose->region_count = 5;
+
+       pci_setup_type1(hose,
+                       SC520_REG_ADDR,
+                       SC520_REG_DATA);
+
+       pci_register_hose(hose);
+
+       hose->last_busno = pci_hose_scan(hose);
+
+       /* enable target memory acceses on host brige */
+       pci_write_config_word(0, PCI_COMMAND,
+                             PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
+
+}
diff --git a/cpu/i386/sc520/sc520_ssi.c b/cpu/i386/sc520/sc520_ssi.c
new file mode 100644 (file)
index 0000000..dd667ca
--- /dev/null
@@ -0,0 +1,92 @@
+/*
+ * (C) Copyright 2002
+ * Daniel Engström, Omicron Ceti AB <daniel@omicron.se>.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/* stuff specific for the sc520, but independent of implementation */
+
+#include <common.h>
+#include <asm/ic/ssi.h>
+#include <asm/ic/sc520.h>
+
+int ssi_set_interface(int freq, int lsb_first, int inv_clock, int inv_phase)
+{
+       u8 temp=0;
+
+       if (freq >= 8192) {
+               temp |= CTL_CLK_SEL_4;
+       } else if (freq >= 4096) {
+               temp |= CTL_CLK_SEL_8;
+       } else if (freq >= 2048) {
+               temp |= CTL_CLK_SEL_16;
+       } else if (freq >= 1024) {
+               temp |= CTL_CLK_SEL_32;
+       } else if (freq >= 512) {
+               temp |= CTL_CLK_SEL_64;
+       } else if (freq >= 256) {
+               temp |= CTL_CLK_SEL_128;
+       } else if (freq >= 128) {
+               temp |= CTL_CLK_SEL_256;
+       } else {
+               temp |= CTL_CLK_SEL_512;
+       }
+
+       if (!lsb_first) {
+               temp |= MSBF_ENB;
+       }
+
+       if (inv_clock) {
+               temp |= CLK_INV_ENB;
+       }
+
+       if (inv_phase) {
+               temp |= PHS_INV_ENB;
+       }
+
+       write_mmcr_byte(SC520_SSICTL, temp);
+
+       return 0;
+}
+
+u8 ssi_txrx_byte(u8 data)
+{
+       write_mmcr_byte(SC520_SSIXMIT, data);
+       while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
+       write_mmcr_byte(SC520_SSICMD, SSICMD_CMD_SEL_XMITRCV);
+       while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
+       return read_mmcr_byte(SC520_SSIRCV);
+}
+
+
+void ssi_tx_byte(u8 data)
+{
+       write_mmcr_byte(SC520_SSIXMIT, data);
+       while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
+       write_mmcr_byte(SC520_SSICMD, SSICMD_CMD_SEL_XMIT);
+}
+
+u8 ssi_rx_byte(void)
+{
+       while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
+       write_mmcr_byte(SC520_SSICMD, SSICMD_CMD_SEL_RCV);
+       while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
+       return read_mmcr_byte(SC520_SSIRCV);
+}
diff --git a/cpu/i386/sc520/sc520_timer.c b/cpu/i386/sc520/sc520_timer.c
new file mode 100644 (file)
index 0000000..7578511
--- /dev/null
@@ -0,0 +1,73 @@
+/*
+ * (C) Copyright 2002
+ * Daniel Engström, Omicron Ceti AB <daniel@omicron.se>.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/* stuff specific for the sc520, but independent of implementation */
+
+#include <common.h>
+#include <asm/interrupt.h>
+#include <asm/ic/sc520.h>
+
+void reset_timer(void)
+{
+       write_mmcr_word(SC520_GPTMR0CNT, 0);
+       write_mmcr_word(SC520_GPTMR0CTL, 0x6001);
+
+}
+
+ulong get_timer(ulong base)
+{
+       /* fixme: 30 or 33 */
+       return  read_mmcr_word(SC520_GPTMR0CNT) / 33;
+}
+
+void set_timer(ulong t)
+{
+       /* FixMe: use two cascade coupled timers */
+       write_mmcr_word(SC520_GPTMR0CTL, 0x4001);
+       write_mmcr_word(SC520_GPTMR0CNT, t*33);
+       write_mmcr_word(SC520_GPTMR0CTL, 0x6001);
+}
+
+
+void udelay(unsigned long usec)
+{
+       int m=0;
+       long u;
+
+       read_mmcr_word(SC520_SWTMRMILLI);
+       read_mmcr_word(SC520_SWTMRMICRO);
+
+#if 0
+       /* do not enable this line, udelay is used in the serial driver -> recursion */
+       printf("udelay: %ld m.u %d.%d  tm.tu %d.%d\n", usec, m, u, tm, tu);
+#endif
+       while (1) {
+
+               m += read_mmcr_word(SC520_SWTMRMILLI);
+               u = read_mmcr_word(SC520_SWTMRMICRO) + (m * 1000);
+
+               if (usec <= u) {
+                       break;
+               }
+       }
+}