linux 2.6.16.38 w/ vs2.0.3-rc1

[linux-2.6.git] / arch / ppc / platforms / chrp_time.c

diff --git a/arch/ppc/platforms/chrp_time.c b/arch/ppc/platforms/chrp_time.c
index 4864a7d..57753a5 100644 (file)
--- a/arch/ppc/platforms/chrp_time.c
+++ b/arch/ppc/platforms/chrp_time.c
@@ -22,7 +22,6 @@
 #include <linux/init.h>
 #include <linux/bcd.h>
 
-#include <asm/segment.h>
 #include <asm/io.h>
 #include <asm/nvram.h>
 #include <asm/prom.h>
@@ -53,7 +52,7 @@ long __init chrp_time_init(void)
        return 0;
 }
 
-int __chrp chrp_cmos_clock_read(int addr)
+int chrp_cmos_clock_read(int addr)
 {
        if (nvram_as1 != 0)
                outb(addr>>8, nvram_as1);
@@ -61,7 +60,7 @@ int __chrp chrp_cmos_clock_read(int addr)
        return (inb(nvram_data));
 }
 
-void __chrp chrp_cmos_clock_write(unsigned long val, int addr)
+void chrp_cmos_clock_write(unsigned long val, int addr)
 {
        if (nvram_as1 != 0)
                outb(addr>>8, nvram_as1);
@@ -73,7 +72,7 @@ void __chrp chrp_cmos_clock_write(unsigned long val, int addr)
 /*
  * Set the hardware clock. -- Cort
  */
-int __chrp chrp_set_rtc_time(unsigned long nowtime)
+int chrp_set_rtc_time(unsigned long nowtime)
 {
        unsigned char save_control, save_freq_select;
        struct rtc_time tm;
@@ -119,7 +118,7 @@ int __chrp chrp_set_rtc_time(unsigned long nowtime)
        return 0;
 }
 
-unsigned long __chrp chrp_get_rtc_time(void)
+unsigned long chrp_get_rtc_time(void)
 {
        unsigned int year, mon, day, hour, min, sec;
        int uip, i;
@@ -164,13 +163,75 @@ unsigned long __chrp chrp_get_rtc_time(void)
        return mktime(year, mon, day, hour, min, sec);
 }
 
+/*
+ * Calibrate the decrementer frequency with the VIA timer 1.
+ */
+#define VIA_TIMER_FREQ_6       4700000 /* time 1 frequency * 6 */
+
+/* VIA registers */
+#define RS             0x200           /* skip between registers */
+#define T1CL           (4*RS)          /* Timer 1 ctr/latch (low 8 bits) */
+#define T1CH           (5*RS)          /* Timer 1 counter (high 8 bits) */
+#define T1LL           (6*RS)          /* Timer 1 latch (low 8 bits) */
+#define T1LH           (7*RS)          /* Timer 1 latch (high 8 bits) */
+#define ACR            (11*RS)         /* Auxiliary control register */
+#define IFR            (13*RS)         /* Interrupt flag register */
+
+/* Bits in ACR */
+#define T1MODE         0xc0            /* Timer 1 mode */
+#define T1MODE_CONT    0x40            /*  continuous interrupts */
+
+/* Bits in IFR and IER */
+#define T1_INT         0x40            /* Timer 1 interrupt */
+
+static int __init chrp_via_calibrate_decr(void)
+{
+       struct device_node *vias;
+       volatile unsigned char __iomem *via;
+       int count = VIA_TIMER_FREQ_6 / 100;
+       unsigned int dstart, dend;
+
+       vias = find_devices("via-cuda");
+       if (vias == 0)
+               vias = find_devices("via");
+       if (vias == 0 || vias->n_addrs == 0)
+               return 0;
+       via = ioremap(vias->addrs[0].address, vias->addrs[0].size);
+
+       /* set timer 1 for continuous interrupts */
+       out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT);
+       /* set the counter to a small value */
+       out_8(&via[T1CH], 2);
+       /* set the latch to `count' */
+       out_8(&via[T1LL], count);
+       out_8(&via[T1LH], count >> 8);
+       /* wait until it hits 0 */
+       while ((in_8(&via[IFR]) & T1_INT) == 0)
+               ;
+       dstart = get_dec();
+       /* clear the interrupt & wait until it hits 0 again */
+       in_8(&via[T1CL]);
+       while ((in_8(&via[IFR]) & T1_INT) == 0)
+               ;
+       dend = get_dec();
+
+       tb_ticks_per_jiffy = (dstart - dend) / ((6 * HZ)/100);
+       tb_to_us = mulhwu_scale_factor(dstart - dend, 60000);
+
+       printk(KERN_INFO "via_calibrate_decr: ticks per jiffy = %u (%u ticks)\n",
+              tb_ticks_per_jiffy, dstart - dend);
+
+       iounmap(via);
+       
+       return 1;
+}
 
 void __init chrp_calibrate_decr(void)
 {
        struct device_node *cpu;
        unsigned int freq, *fp;
 
-       if (via_calibrate_decr())
+       if (chrp_via_calibrate_decr())
                return;
 
        /*