aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/platform/intel-mid/mrfl.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/platform/intel-mid/mrfl.c')
-rw-r--r--arch/x86/platform/intel-mid/mrfl.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/x86/platform/intel-mid/mrfl.c b/arch/x86/platform/intel-mid/mrfl.c
new file mode 100644
index 000000000000..09d10159e7b7
--- /dev/null
+++ b/arch/x86/platform/intel-mid/mrfl.c
@@ -0,0 +1,103 @@
+/*
+ * mrfl.c: Intel Merrifield platform specific setup code
+ *
+ * (C) Copyright 2013 Intel Corporation
+ *
+ * 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; version 2
+ * of the License.
+ */
+
+#include <linux/init.h>
+
+#include <asm/apic.h>
+#include <asm/intel-mid.h>
+
+#include "intel_mid_weak_decls.h"
+
+static unsigned long __init tangier_calibrate_tsc(void)
+{
+ unsigned long fast_calibrate;
+ u32 lo, hi, ratio, fsb, bus_freq;
+
+ /* *********************** */
+ /* Compute TSC:Ratio * FSB */
+ /* *********************** */
+
+ /* Compute Ratio */
+ rdmsr(MSR_PLATFORM_INFO, lo, hi);
+ pr_debug("IA32 PLATFORM_INFO is 0x%x : %x\n", hi, lo);
+
+ ratio = (lo >> 8) & 0xFF;
+ pr_debug("ratio is %d\n", ratio);
+ if (!ratio) {
+ pr_err("Read a zero ratio, force tsc ratio to 4 ...\n");
+ ratio = 4;
+ }
+
+ /* Compute FSB */
+ rdmsr(MSR_FSB_FREQ, lo, hi);
+ pr_debug("Actual FSB frequency detected by SOC 0x%x : %x\n",
+ hi, lo);
+
+ bus_freq = lo & 0x7;
+ pr_debug("bus_freq = 0x%x\n", bus_freq);
+
+ if (bus_freq == 0)
+ fsb = FSB_FREQ_100SKU;
+ else if (bus_freq == 1)
+ fsb = FSB_FREQ_100SKU;
+ else if (bus_freq == 2)
+ fsb = FSB_FREQ_133SKU;
+ else if (bus_freq == 3)
+ fsb = FSB_FREQ_167SKU;
+ else if (bus_freq == 4)
+ fsb = FSB_FREQ_83SKU;
+ else if (bus_freq == 5)
+ fsb = FSB_FREQ_400SKU;
+ else if (bus_freq == 6)
+ fsb = FSB_FREQ_267SKU;
+ else if (bus_freq == 7)
+ fsb = FSB_FREQ_333SKU;
+ else {
+ BUG();
+ pr_err("Invalid bus_freq! Setting to minimal value!\n");
+ fsb = FSB_FREQ_100SKU;
+ }
+
+ /* TSC = FSB Freq * Resolved HFM Ratio */
+ fast_calibrate = ratio * fsb;
+ pr_debug("calculate tangier tsc %lu KHz\n", fast_calibrate);
+
+ /* ************************************ */
+ /* Calculate Local APIC Timer Frequency */
+ /* ************************************ */
+ lapic_timer_frequency = (fsb * 1000) / HZ;
+
+ pr_debug("Setting lapic_timer_frequency = %d\n",
+ lapic_timer_frequency);
+
+ /* mark tsc clocksource as reliable */
+ set_cpu_cap(&boot_cpu_data, X86_FEATURE_TSC_RELIABLE);
+
+ if (fast_calibrate)
+ return fast_calibrate;
+
+ return 0;
+}
+
+static void __init tangier_arch_setup(void)
+{
+ x86_platform.calibrate_tsc = tangier_calibrate_tsc;
+}
+
+/* tangier arch ops */
+static struct intel_mid_ops tangier_ops = {
+ .arch_setup = tangier_arch_setup,
+};
+
+void * __cpuinit get_tangier_ops()
+{
+ return &tangier_ops;
+}