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 	/* Shut down South Complex via PWRMU */
74 	intel_mid_pwr_power_off();
75 
76 	/* Only for Tangier, the rest will ignore this command */
77 	intel_scu_ipc_simple_command(IPCMSG_COLD_OFF, 1);
78 };
79 
80 static void intel_mid_reboot(void)
81 {
82 	intel_scu_ipc_simple_command(IPCMSG_COLD_BOOT, 0);
83 }
84 
85 static unsigned long __init intel_mid_calibrate_tsc(void)
86 {
87 	return 0;
88 }
89 
90 static void __init intel_mid_setup_bp_timer(void)
91 {
92 	apbt_time_init();
93 	setup_boot_APIC_clock();
94 }
95 
96 static void __init intel_mid_time_init(void)
97 {
98 	sfi_table_parse(SFI_SIG_MTMR, NULL, NULL, sfi_parse_mtmr);
99 
100 	switch (intel_mid_timer_options) {
101 	case INTEL_MID_TIMER_APBT_ONLY:
102 		break;
103 	case INTEL_MID_TIMER_LAPIC_APBT:
104 		/* Use apbt and local apic */
105 		x86_init.timers.setup_percpu_clockev = intel_mid_setup_bp_timer;
106 		x86_cpuinit.setup_percpu_clockev = setup_secondary_APIC_clock;
107 		return;
108 	default:
109 		if (!boot_cpu_has(X86_FEATURE_ARAT))
110 			break;
111 		/* Lapic only, no apbt */
112 		x86_init.timers.setup_percpu_clockev = setup_boot_APIC_clock;
113 		x86_cpuinit.setup_percpu_clockev = setup_secondary_APIC_clock;
114 		return;
115 	}
116 
117 	x86_init.timers.setup_percpu_clockev = apbt_time_init;
118 }
119 
120 static void intel_mid_arch_setup(void)
121 {
122 	if (boot_cpu_data.x86 != 6) {
123 		pr_err("Unknown Intel MID CPU (%d:%d), default to Penwell\n",
124 			boot_cpu_data.x86, boot_cpu_data.x86_model);
125 		__intel_mid_cpu_chip = INTEL_MID_CPU_CHIP_PENWELL;
126 		goto out;
127 	}
128 
129 	switch (boot_cpu_data.x86_model) {
130 	case 0x35:
131 		__intel_mid_cpu_chip = INTEL_MID_CPU_CHIP_CLOVERVIEW;
132 		break;
133 	case 0x3C:
134 	case 0x4A:
135 		__intel_mid_cpu_chip = INTEL_MID_CPU_CHIP_TANGIER;
136 		break;
137 	case 0x27:
138 	default:
139 		__intel_mid_cpu_chip = INTEL_MID_CPU_CHIP_PENWELL;
140 		break;
141 	}
142 
143 	if (__intel_mid_cpu_chip < MAX_CPU_OPS(get_intel_mid_ops))
144 		intel_mid_ops = get_intel_mid_ops[__intel_mid_cpu_chip]();
145 	else {
146 		intel_mid_ops = get_intel_mid_ops[INTEL_MID_CPU_CHIP_PENWELL]();
147 		pr_info("ARCH: Unknown SoC, assuming Penwell!\n");
148 	}
149 
150 out:
151 	if (intel_mid_ops->arch_setup)
152 		intel_mid_ops->arch_setup();
153 
154 	/*
155 	 * Intel MID platforms are using explicitly defined regulators.
156 	 *
157 	 * Let the regulator core know that we do not have any additional
158 	 * regulators left. This lets it substitute unprovided regulators with
159 	 * dummy ones:
160 	 */
161 	regulator_has_full_constraints();
162 }
163 
164 /*
165  * Moorestown does not have external NMI source nor port 0x61 to report
166  * NMI status. The possible NMI sources are from pmu as a result of NMI
167  * watchdog or lock debug. Reading io port 0x61 results in 0xff which
168  * misled NMI handler.
169  */
170 static unsigned char intel_mid_get_nmi_reason(void)
171 {
172 	return 0;
173 }
174 
175 /*
176  * Moorestown specific x86_init function overrides and early setup
177  * calls.
178  */
179 void __init x86_intel_mid_early_setup(void)
180 {
181 	x86_init.resources.probe_roms = x86_init_noop;
182 	x86_init.resources.reserve_resources = x86_init_noop;
183 
184 	x86_init.timers.timer_init = intel_mid_time_init;
185 	x86_init.timers.setup_percpu_clockev = x86_init_noop;
186 	x86_init.timers.wallclock_init = intel_mid_rtc_init;
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.get_nmi_reason = intel_mid_get_nmi_reason;
196 
197 	x86_init.pci.init = intel_mid_pci_init;
198 	x86_init.pci.fixup_irqs = x86_init_noop;
199 
200 	legacy_pic = &null_legacy_pic;
201 
202 	pm_power_off = intel_mid_power_off;
203 	machine_ops.emergency_restart  = intel_mid_reboot;
204 
205 	/* Avoid searching for BIOS MP tables */
206 	x86_init.mpparse.find_smp_config = x86_init_noop;
207 	x86_init.mpparse.get_smp_config = x86_init_uint_noop;
208 	set_bit(MP_BUS_ISA, mp_bus_not_pci);
209 }
210 
211 /*
212  * if user does not want to use per CPU apb timer, just give it a lower rating
213  * than local apic timer and skip the late per cpu timer init.
214  */
215 static inline int __init setup_x86_intel_mid_timer(char *arg)
216 {
217 	if (!arg)
218 		return -EINVAL;
219 
220 	if (strcmp("apbt_only", arg) == 0)
221 		intel_mid_timer_options = INTEL_MID_TIMER_APBT_ONLY;
222 	else if (strcmp("lapic_and_apbt", arg) == 0)
223 		intel_mid_timer_options = INTEL_MID_TIMER_LAPIC_APBT;
224 	else {
225 		pr_warn("X86 INTEL_MID timer option %s not recognised use x86_intel_mid_timer=apbt_only or lapic_and_apbt\n",
226 			arg);
227 		return -EINVAL;
228 	}
229 	return 0;
230 }
231 __setup("x86_intel_mid_timer=", setup_x86_intel_mid_timer);
232