2 * intel-mid.c: Intel MID platform setup code
4 * (C) Copyright 2008, 2012 Intel Corporation
5 * Author: Jacob Pan (jacob.jun.pan@intel.com)
6 * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; version 2
14 #define pr_fmt(fmt) "intel_mid: " fmt
16 #include <linux/init.h>
17 #include <linux/kernel.h>
18 #include <linux/interrupt.h>
19 #include <linux/scatterlist.h>
20 #include <linux/sfi.h>
21 #include <linux/irq.h>
22 #include <linux/module.h>
23 #include <linux/notifier.h>
25 #include <asm/setup.h>
26 #include <asm/mpspec_def.h>
27 #include <asm/hw_irq.h>
29 #include <asm/io_apic.h>
30 #include <asm/intel-mid.h>
31 #include <asm/intel_mid_vrtc.h>
33 #include <asm/i8259.h>
34 #include <asm/intel_scu_ipc.h>
35 #include <asm/apb_timer.h>
36 #include <asm/reboot.h>
39 * the clockevent devices on Moorestown/Medfield can be APBT or LAPIC clock,
40 * cmdline option x86_intel_mid_timer can be used to override the configuration
41 * to prefer one or the other.
42 * at runtime, there are basically three timer configurations:
43 * 1. per cpu apbt clock only
44 * 2. per cpu always-on lapic clocks only, this is Penwell/Medfield only
45 * 3. per cpu lapic clock (C3STOP) and one apbt clock, with broadcast.
47 * by default (without cmdline option), platform code first detects cpu type
48 * to see if we are on lincroft or penwell, then set up both lapic or apbt
50 * i.e. by default, medfield uses configuration #2, moorestown uses #1.
51 * config #3 is supported but not recommended on medfield.
53 * rating and feature summary:
54 * lapic (with C3STOP) --------- 100
55 * apbt (always-on) ------------ 110
56 * lapic (always-on,ARAT) ------ 150
59 enum intel_mid_timer_options intel_mid_timer_options;
61 enum intel_mid_cpu_type __intel_mid_cpu_chip;
62 EXPORT_SYMBOL_GPL(__intel_mid_cpu_chip);
64 static void intel_mid_power_off(void)
68 static void intel_mid_reboot(void)
70 intel_scu_ipc_simple_command(IPCMSG_COLD_BOOT, 0);
73 static unsigned long __init intel_mid_calibrate_tsc(void)
75 unsigned long fast_calibrate;
76 u32 lo, hi, ratio, fsb;
78 rdmsr(MSR_IA32_PERF_STATUS, lo, hi);
79 pr_debug("IA32 perf status is 0x%x, 0x%0x\n", lo, hi);
80 ratio = (hi >> 8) & 0x1f;
81 pr_debug("ratio is %d\n", ratio);
83 pr_err("read a zero ratio, should be incorrect!\n");
84 pr_err("force tsc ratio to 16 ...\n");
87 rdmsr(MSR_FSB_FREQ, lo, hi);
88 if ((lo & 0x7) == 0x7)
89 fsb = PENWELL_FSB_FREQ_83SKU;
91 fsb = PENWELL_FSB_FREQ_100SKU;
92 fast_calibrate = ratio * fsb;
93 pr_debug("read penwell tsc %lu khz\n", fast_calibrate);
94 lapic_timer_frequency = fsb * 1000 / HZ;
95 /* mark tsc clocksource as reliable */
96 set_cpu_cap(&boot_cpu_data, X86_FEATURE_TSC_RELIABLE);
99 return fast_calibrate;
104 static void __init intel_mid_time_init(void)
106 sfi_table_parse(SFI_SIG_MTMR, NULL, NULL, sfi_parse_mtmr);
107 switch (intel_mid_timer_options) {
108 case INTEL_MID_TIMER_APBT_ONLY:
110 case INTEL_MID_TIMER_LAPIC_APBT:
111 x86_init.timers.setup_percpu_clockev = setup_boot_APIC_clock;
112 x86_cpuinit.setup_percpu_clockev = setup_secondary_APIC_clock;
115 if (!boot_cpu_has(X86_FEATURE_ARAT))
117 x86_init.timers.setup_percpu_clockev = setup_boot_APIC_clock;
118 x86_cpuinit.setup_percpu_clockev = setup_secondary_APIC_clock;
121 /* we need at least one APB timer */
122 pre_init_apic_IRQ0();
126 static void __cpuinit intel_mid_arch_setup(void)
128 if (boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model == 0x27)
129 __intel_mid_cpu_chip = INTEL_MID_CPU_CHIP_PENWELL;
131 pr_err("Unknown Intel MID CPU (%d:%d), default to Penwell\n",
132 boot_cpu_data.x86, boot_cpu_data.x86_model);
133 __intel_mid_cpu_chip = INTEL_MID_CPU_CHIP_PENWELL;
137 /* MID systems don't have i8042 controller */
138 static int intel_mid_i8042_detect(void)
144 * Moorestown does not have external NMI source nor port 0x61 to report
145 * NMI status. The possible NMI sources are from pmu as a result of NMI
146 * watchdog or lock debug. Reading io port 0x61 results in 0xff which
147 * misled NMI handler.
149 static unsigned char intel_mid_get_nmi_reason(void)
155 * Moorestown specific x86_init function overrides and early setup
158 void __init x86_intel_mid_early_setup(void)
160 x86_init.resources.probe_roms = x86_init_noop;
161 x86_init.resources.reserve_resources = x86_init_noop;
163 x86_init.timers.timer_init = intel_mid_time_init;
164 x86_init.timers.setup_percpu_clockev = x86_init_noop;
166 x86_init.irqs.pre_vector_init = x86_init_noop;
168 x86_init.oem.arch_setup = intel_mid_arch_setup;
170 x86_cpuinit.setup_percpu_clockev = apbt_setup_secondary_clock;
172 x86_platform.calibrate_tsc = intel_mid_calibrate_tsc;
173 x86_platform.i8042_detect = intel_mid_i8042_detect;
174 x86_init.timers.wallclock_init = intel_mid_rtc_init;
175 x86_platform.get_nmi_reason = intel_mid_get_nmi_reason;
177 x86_init.pci.init = intel_mid_pci_init;
178 x86_init.pci.fixup_irqs = x86_init_noop;
180 legacy_pic = &null_legacy_pic;
182 pm_power_off = intel_mid_power_off;
183 machine_ops.emergency_restart = intel_mid_reboot;
185 /* Avoid searching for BIOS MP tables */
186 x86_init.mpparse.find_smp_config = x86_init_noop;
187 x86_init.mpparse.get_smp_config = x86_init_uint_noop;
188 set_bit(MP_BUS_ISA, mp_bus_not_pci);
192 * if user does not want to use per CPU apb timer, just give it a lower rating
193 * than local apic timer and skip the late per cpu timer init.
195 static inline int __init setup_x86_intel_mid_timer(char *arg)
200 if (strcmp("apbt_only", arg) == 0)
201 intel_mid_timer_options = INTEL_MID_TIMER_APBT_ONLY;
202 else if (strcmp("lapic_and_apbt", arg) == 0)
203 intel_mid_timer_options = INTEL_MID_TIMER_LAPIC_APBT;
205 pr_warn("X86 INTEL_MID timer option %s not recognised"
206 " use x86_intel_mid_timer=apbt_only or lapic_and_apbt\n",
212 __setup("x86_intel_mid_timer=", setup_x86_intel_mid_timer);