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From 7d6656dc127b54e53e507e8f264bb7e14e620cad Mon Sep 17 00:00:00 2001
From: Axel Gembe <ago@bastart.eu.org>
Date: Sat, 17 May 2008 15:02:39 +0200
Subject: [PATCH] bcm963xx: add new timer code
This basically selects the new generic MIPS timer code for BCM963xx and
simplifies the timer setup code.
Signed-off-by: Axel Gembe <ago@bastart.eu.org>
---
arch/mips/Kconfig | 2 +
arch/mips/bcm963xx/time.c | 64 ++++++++++++++++++++------------------------
2 files changed, 31 insertions(+), 35 deletions(-)
Index: linux-2.6.25.4/arch/mips/Kconfig
===================================================================
--- linux-2.6.25.4.orig/arch/mips/Kconfig
+++ linux-2.6.25.4/arch/mips/Kconfig
@@ -67,6 +67,8 @@ config BCM963XX
select HW_HAS_PCI
select DMA_NONCOHERENT
select IRQ_CPU
+ select CEVT_R4K
+ select CSRC_R4K
help
This is a fmaily of boards based on the Broadcom MIPS32
Index: linux-2.6.25.4/arch/mips/bcm963xx/time.c
===================================================================
--- linux-2.6.25.4.orig/arch/mips/bcm963xx/time.c
+++ linux-2.6.25.4/arch/mips/bcm963xx/time.c
@@ -1,6 +1,7 @@
/*
<:copyright-gpl
Copyright 2004 Broadcom Corp. All Rights Reserved.
+ Copyright (C) 2008 Axel Gembe <ago@bastart.eu.org>
This program is free software; you can distribute it and/or modify it
under the terms of the GNU General Public License (Version 2) as
@@ -40,50 +41,43 @@
#include <bcm_map_part.h>
#include <bcm_intr.h>
-static unsigned long r4k_offset; /* Amount to increment compare reg each time */
-static unsigned long r4k_cur; /* What counter should be at next timer irq */
-
-/* *********************************************************************
- * calculateCpuSpeed()
- * Calculate the BCM6348 CPU speed by reading the PLL strap register
- * and applying the following formula:
- * cpu_clk = (.25 * 64MHz freq) * (N1 + 1) * (N2 + 2) / (M1_CPU + 1)
- * Input parameters:
- * none
- * Return value:
- * none
- ********************************************************************* */
-
+/*
+ * calculateCpuSpeed()
+ *
+ * Calculate the BCM6348 CPU speed by reading the PLL strap register and applying
+ * the following formula:
+ *
+ * cpu_clk = (.25 * 64MHz freq) * (N1 + 1) * (N2 + 2) / (M1_CPU + 1)
+ */
static inline unsigned long __init calculateCpuSpeed(void)
{
- u32 pllStrap = PERF->PllStrap;
- int n1 = (pllStrap & PLL_N1_MASK) >> PLL_N1_SHFT;
- int n2 = (pllStrap & PLL_N2_MASK) >> PLL_N2_SHFT;
- int m1cpu = (pllStrap & PLL_M1_CPU_MASK) >> PLL_M1_CPU_SHFT;
+ u32 pllStrap;
+ int n1, n2, m1cpu;
+
+ pllStrap = PERF->PllStrap;
+ n1 = (pllStrap & PLL_N1_MASK) >> PLL_N1_SHFT;
+ n2 = (pllStrap & PLL_N2_MASK) >> PLL_N2_SHFT;
+ m1cpu = (pllStrap & PLL_M1_CPU_MASK) >> PLL_M1_CPU_SHFT;
return (16 * (n1 + 1) * (n2 + 2) / (m1cpu + 1)) * 1000000;
}
-static inline unsigned long __init cal_r4koff(void)
-{
- mips_hpt_frequency = calculateCpuSpeed() / 2;
- return (mips_hpt_frequency / HZ);
-}
-
void __init plat_time_init(void)
{
- unsigned int est_freq, flags;
- local_irq_save(flags);
+ unsigned long cpu_clock;
+
+ cpu_clock = calculateCpuSpeed();
+
+ printk("CPU frequency %lu.%02lu MHz\n", cpu_clock / 1000000,
+ (cpu_clock % 1000000) * 100 / 1000000);
+
+ mips_hpt_frequency = cpu_clock / 2;
- printk("calculating r4koff... ");
- r4k_offset = cal_r4koff();
- printk("%08lx(%d)\n", r4k_offset, (int)r4k_offset);
-
- est_freq = 2 * r4k_offset * HZ;
- est_freq += 5000; /* round */
- est_freq -= est_freq % 10000;
- printk("CPU frequency %d.%02d MHz\n", est_freq / 1000000,
- (est_freq % 1000000) * 100 / 1000000);
- local_irq_restore(flags);
+ /*
+ * Use deterministic values for initial counter interrupt
+ * so that calibrate delay avoids encountering a counter wrap.
+ */
+ write_c0_count(0);
+ write_c0_compare(0xffff);
}
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