1 /*
2  * intel-mid.c: Intel MID platform setup code
3  *
4  * (C) Copyright 2008, 2012 Intel Corporation
5  * Author: Jacob Pan (jacob.jun.pan@intel.com)
6  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
7  *
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
11  * of the License.
12  */
13 
14 #define pr_fmt(fmt) "intel_mid: " fmt
15 
16 #include <linux/init.h>
17 #include <linux/kernel.h>
18 #include <linux/interrupt.h>
19 #include <linux/regulator/machine.h>
20 #include <linux/scatterlist.h>
21 #include <linux/sfi.h>
22 #include <linux/irq.h>
23 #include <linux/export.h>
24 #include <linux/notifier.h>
25 
26 #include <asm/setup.h>
27 #include <asm/mpspec_def.h>
28 #include <asm/hw_irq.h>
29 #include <asm/apic.h>
30 #include <asm/io_apic.h>
31 #include <asm/intel-mid.h>
32 #include <asm/intel_mid_vrtc.h>
33 #include <asm/io.h>
34 #include <asm/i8259.h>
35 #include <asm/intel_scu_ipc.h>
36 #include <asm/apb_timer.h>
37 #include <asm/reboot.h>
38 
39 #include "intel_mid_weak_decls.h"
40 
41 /*
42  * the clockevent devices on Moorestown/Medfield can be APBT or LAPIC clock,
43  * cmdline option x86_intel_mid_timer can be used to override the configuration
44  * to prefer one or the other.
45  * at runtime, there are basically three timer configurations:
46  * 1. per cpu apbt clock only
47  * 2. per cpu always-on lapic clocks only, this is Penwell/Medfield only
48  * 3. per cpu lapic clock (C3STOP) and one apbt clock, with broadcast.
49  *
50  * by default (without cmdline option), platform code first detects cpu type
51  * to see if we are on lincroft or penwell, then set up both lapic or apbt
52  * clocks accordingly.
53  * i.e. by default, medfield uses configuration #2, moorestown uses #1.
54  * config #3 is supported but not recommended on medfield.
55  *
56  * rating and feature summary:
57  * lapic (with C3STOP) --------- 100
58  * apbt (always-on) ------------ 110
59  * lapic (always-on,ARAT) ------ 150
60  */
61 
62 enum intel_mid_timer_options intel_mid_timer_options;
63 
64 /* intel_mid_ops to store sub arch ops */
65 static struct intel_mid_ops *intel_mid_ops;
66 /* getter function for sub arch ops*/
67 static void *(*get_intel_mid_ops[])(void) = INTEL_MID_OPS_INIT;
68 enum intel_mid_cpu_type __intel_mid_cpu_chip;
69 EXPORT_SYMBOL_GPL(__intel_mid_cpu_chip);
70 
71 static void intel_mid_power_off(void)
72 {
73 };
74 
75 static void intel_mid_reboot(void)
76 {
77 	intel_scu_ipc_simple_command(IPCMSG_COLD_BOOT, 0);
78 }
79 
80 static unsigned long __init intel_mid_calibrate_tsc(void)
81 {
82 	return 0;
83 }
84 
85 static void __init intel_mid_setup_bp_timer(void)
86 {
87 	apbt_time_init();
88 	setup_boot_APIC_clock();
89 }
90 
91 static void __init intel_mid_time_init(void)
92 {
93 	sfi_table_parse(SFI_SIG_MTMR, NULL, NULL, sfi_parse_mtmr);
94 
95 	switch (intel_mid_timer_options) {
96 	case INTEL_MID_TIMER_APBT_ONLY:
97 		break;
98 	case INTEL_MID_TIMER_LAPIC_APBT:
99 		/* Use apbt and local apic */
100 		x86_init.timers.setup_percpu_clockev = intel_mid_setup_bp_timer;
101 		x86_cpuinit.setup_percpu_clockev = setup_secondary_APIC_clock;
102 		return;
103 	default:
104 		if (!boot_cpu_has(X86_FEATURE_ARAT))
105 			break;
106 		/* Lapic only, no apbt */
107 		x86_init.timers.setup_percpu_clockev = setup_boot_APIC_clock;
108 		x86_cpuinit.setup_percpu_clockev = setup_secondary_APIC_clock;
109 		return;
110 	}
111 
112 	x86_init.timers.setup_percpu_clockev = apbt_time_init;
113 }
114 
115 static void intel_mid_arch_setup(void)
116 {
117 	if (boot_cpu_data.x86 != 6) {
118 		pr_err("Unknown Intel MID CPU (%d:%d), default to Penwell\n",
119 			boot_cpu_data.x86, boot_cpu_data.x86_model);
120 		__intel_mid_cpu_chip = INTEL_MID_CPU_CHIP_PENWELL;
121 		goto out;
122 	}
123 
124 	switch (boot_cpu_data.x86_model) {
125 	case 0x35:
126 		__intel_mid_cpu_chip = INTEL_MID_CPU_CHIP_CLOVERVIEW;
127 		break;
128 	case 0x3C:
129 	case 0x4A:
130 		__intel_mid_cpu_chip = INTEL_MID_CPU_CHIP_TANGIER;
131 		break;
132 	case 0x27:
133 	default:
134 		__intel_mid_cpu_chip = INTEL_MID_CPU_CHIP_PENWELL;
135 		break;
136 	}
137 
138 	if (__intel_mid_cpu_chip < MAX_CPU_OPS(get_intel_mid_ops))
139 		intel_mid_ops = get_intel_mid_ops[__intel_mid_cpu_chip]();
140 	else {
141 		intel_mid_ops = get_intel_mid_ops[INTEL_MID_CPU_CHIP_PENWELL]();
142 		pr_info("ARCH: Unknown SoC, assuming Penwell!\n");
143 	}
144 
145 out:
146 	if (intel_mid_ops->arch_setup)
147 		intel_mid_ops->arch_setup();
148 
149 	/*
150 	 * Intel MID platforms are using explicitly defined regulators.
151 	 *
152 	 * Let the regulator core know that we do not have any additional
153 	 * regulators left. This lets it substitute unprovided regulators with
154 	 * dummy ones:
155 	 */
156 	regulator_has_full_constraints();
157 }
158 
159 /* MID systems don't have i8042 controller */
160 static int intel_mid_i8042_detect(void)
161 {
162 	return 0;
163 }
164 
165 /*
166  * Moorestown does not have external NMI source nor port 0x61 to report
167  * NMI status. The possible NMI sources are from pmu as a result of NMI
168  * watchdog or lock debug. Reading io port 0x61 results in 0xff which
169  * misled NMI handler.
170  */
171 static unsigned char intel_mid_get_nmi_reason(void)
172 {
173 	return 0;
174 }
175 
176 /*
177  * Moorestown specific x86_init function overrides and early setup
178  * calls.
179  */
180 void __init x86_intel_mid_early_setup(void)
181 {
182 	x86_init.resources.probe_roms = x86_init_noop;
183 	x86_init.resources.reserve_resources = x86_init_noop;
184 
185 	x86_init.timers.timer_init = intel_mid_time_init;
186 	x86_init.timers.setup_percpu_clockev = x86_init_noop;
187 
188 	x86_init.irqs.pre_vector_init = x86_init_noop;
189 
190 	x86_init.oem.arch_setup = intel_mid_arch_setup;
191 
192 	x86_cpuinit.setup_percpu_clockev = apbt_setup_secondary_clock;
193 
194 	x86_platform.calibrate_tsc = intel_mid_calibrate_tsc;
195 	x86_platform.i8042_detect = intel_mid_i8042_detect;
196 	x86_init.timers.wallclock_init = intel_mid_rtc_init;
197 	x86_platform.get_nmi_reason = intel_mid_get_nmi_reason;
198 
199 	x86_init.pci.init = intel_mid_pci_init;
200 	x86_init.pci.fixup_irqs = x86_init_noop;
201 
202 	legacy_pic = &null_legacy_pic;
203 
204 	pm_power_off = intel_mid_power_off;
205 	machine_ops.emergency_restart  = intel_mid_reboot;
206 
207 	/* Avoid searching for BIOS MP tables */
208 	x86_init.mpparse.find_smp_config = x86_init_noop;
209 	x86_init.mpparse.get_smp_config = x86_init_uint_noop;
210 	set_bit(MP_BUS_ISA, mp_bus_not_pci);
211 }
212 
213 /*
214  * if user does not want to use per CPU apb timer, just give it a lower rating
215  * than local apic timer and skip the late per cpu timer init.
216  */
217 static inline int __init setup_x86_intel_mid_timer(char *arg)
218 {
219 	if (!arg)
220 		return -EINVAL;
221 
222 	if (strcmp("apbt_only", arg) == 0)
223 		intel_mid_timer_options = INTEL_MID_TIMER_APBT_ONLY;
224 	else if (strcmp("lapic_and_apbt", arg) == 0)
225 		intel_mid_timer_options = INTEL_MID_TIMER_LAPIC_APBT;
226 	else {
227 		pr_warn("X86 INTEL_MID timer option %s not recognised use x86_intel_mid_timer=apbt_only or lapic_and_apbt\n",
228 			arg);
229 		return -EINVAL;
230 	}
231 	return 0;
232 }
233 __setup("x86_intel_mid_timer=", setup_x86_intel_mid_timer);
234