1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * intel-mid.c: Intel MID platform setup code
4 *
5 * (C) Copyright 2008, 2012 Intel Corporation
6 * Author: Jacob Pan (jacob.jun.pan@intel.com)
7 * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
8 */
9
10 #define pr_fmt(fmt) "intel_mid: " fmt
11
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/interrupt.h>
15 #include <linux/regulator/machine.h>
16 #include <linux/scatterlist.h>
17 #include <linux/sfi.h>
18 #include <linux/irq.h>
19 #include <linux/export.h>
20 #include <linux/notifier.h>
21
22 #include <asm/setup.h>
23 #include <asm/mpspec_def.h>
24 #include <asm/hw_irq.h>
25 #include <asm/apic.h>
26 #include <asm/io_apic.h>
27 #include <asm/intel-mid.h>
28 #include <asm/intel_mid_vrtc.h>
29 #include <asm/io.h>
30 #include <asm/i8259.h>
31 #include <asm/intel_scu_ipc.h>
32 #include <asm/apb_timer.h>
33 #include <asm/reboot.h>
34
35 /*
36 * the clockevent devices on Moorestown/Medfield can be APBT or LAPIC clock,
37 * cmdline option x86_intel_mid_timer can be used to override the configuration
38 * to prefer one or the other.
39 * at runtime, there are basically three timer configurations:
40 * 1. per cpu apbt clock only
41 * 2. per cpu always-on lapic clocks only, this is Penwell/Medfield only
42 * 3. per cpu lapic clock (C3STOP) and one apbt clock, with broadcast.
43 *
44 * by default (without cmdline option), platform code first detects cpu type
45 * to see if we are on lincroft or penwell, then set up both lapic or apbt
46 * clocks accordingly.
47 * i.e. by default, medfield uses configuration #2, moorestown uses #1.
48 * config #3 is supported but not recommended on medfield.
49 *
50 * rating and feature summary:
51 * lapic (with C3STOP) --------- 100
52 * apbt (always-on) ------------ 110
53 * lapic (always-on,ARAT) ------ 150
54 */
55
56 enum intel_mid_timer_options intel_mid_timer_options;
57
58 enum intel_mid_cpu_type __intel_mid_cpu_chip;
59 EXPORT_SYMBOL_GPL(__intel_mid_cpu_chip);
60
intel_mid_power_off(void)61 static void intel_mid_power_off(void)
62 {
63 /* Shut down South Complex via PWRMU */
64 intel_mid_pwr_power_off();
65
66 /* Only for Tangier, the rest will ignore this command */
67 intel_scu_ipc_simple_command(IPCMSG_COLD_OFF, 1);
68 };
69
intel_mid_reboot(void)70 static void intel_mid_reboot(void)
71 {
72 intel_scu_ipc_simple_command(IPCMSG_COLD_RESET, 0);
73 }
74
intel_mid_setup_bp_timer(void)75 static void __init intel_mid_setup_bp_timer(void)
76 {
77 apbt_time_init();
78 setup_boot_APIC_clock();
79 }
80
intel_mid_time_init(void)81 static void __init intel_mid_time_init(void)
82 {
83 sfi_table_parse(SFI_SIG_MTMR, NULL, NULL, sfi_parse_mtmr);
84
85 switch (intel_mid_timer_options) {
86 case INTEL_MID_TIMER_APBT_ONLY:
87 break;
88 case INTEL_MID_TIMER_LAPIC_APBT:
89 /* Use apbt and local apic */
90 x86_init.timers.setup_percpu_clockev = intel_mid_setup_bp_timer;
91 x86_cpuinit.setup_percpu_clockev = setup_secondary_APIC_clock;
92 return;
93 default:
94 if (!boot_cpu_has(X86_FEATURE_ARAT))
95 break;
96 /* Lapic only, no apbt */
97 x86_init.timers.setup_percpu_clockev = setup_boot_APIC_clock;
98 x86_cpuinit.setup_percpu_clockev = setup_secondary_APIC_clock;
99 return;
100 }
101
102 x86_init.timers.setup_percpu_clockev = apbt_time_init;
103 }
104
intel_mid_arch_setup(void)105 static void intel_mid_arch_setup(void)
106 {
107 if (boot_cpu_data.x86 != 6) {
108 pr_err("Unknown Intel MID CPU (%d:%d), default to Penwell\n",
109 boot_cpu_data.x86, boot_cpu_data.x86_model);
110 __intel_mid_cpu_chip = INTEL_MID_CPU_CHIP_PENWELL;
111 goto out;
112 }
113
114 switch (boot_cpu_data.x86_model) {
115 case 0x35:
116 __intel_mid_cpu_chip = INTEL_MID_CPU_CHIP_CLOVERVIEW;
117 break;
118 case 0x3C:
119 case 0x4A:
120 __intel_mid_cpu_chip = INTEL_MID_CPU_CHIP_TANGIER;
121 x86_platform.legacy.rtc = 1;
122 break;
123 case 0x27:
124 default:
125 __intel_mid_cpu_chip = INTEL_MID_CPU_CHIP_PENWELL;
126 break;
127 }
128
129 out:
130 /*
131 * Intel MID platforms are using explicitly defined regulators.
132 *
133 * Let the regulator core know that we do not have any additional
134 * regulators left. This lets it substitute unprovided regulators with
135 * dummy ones:
136 */
137 regulator_has_full_constraints();
138 }
139
140 /*
141 * Moorestown does not have external NMI source nor port 0x61 to report
142 * NMI status. The possible NMI sources are from pmu as a result of NMI
143 * watchdog or lock debug. Reading io port 0x61 results in 0xff which
144 * misled NMI handler.
145 */
intel_mid_get_nmi_reason(void)146 static unsigned char intel_mid_get_nmi_reason(void)
147 {
148 return 0;
149 }
150
151 /*
152 * Moorestown specific x86_init function overrides and early setup
153 * calls.
154 */
x86_intel_mid_early_setup(void)155 void __init x86_intel_mid_early_setup(void)
156 {
157 x86_init.resources.probe_roms = x86_init_noop;
158 x86_init.resources.reserve_resources = x86_init_noop;
159
160 x86_init.timers.timer_init = intel_mid_time_init;
161 x86_init.timers.setup_percpu_clockev = x86_init_noop;
162 x86_init.timers.wallclock_init = intel_mid_rtc_init;
163
164 x86_init.irqs.pre_vector_init = x86_init_noop;
165
166 x86_init.oem.arch_setup = intel_mid_arch_setup;
167
168 x86_cpuinit.setup_percpu_clockev = apbt_setup_secondary_clock;
169
170 x86_platform.get_nmi_reason = intel_mid_get_nmi_reason;
171
172 x86_init.pci.arch_init = intel_mid_pci_init;
173 x86_init.pci.fixup_irqs = x86_init_noop;
174
175 legacy_pic = &null_legacy_pic;
176
177 /*
178 * Do nothing for now as everything needed done in
179 * x86_intel_mid_early_setup() below.
180 */
181 x86_init.acpi.reduced_hw_early_init = x86_init_noop;
182
183 pm_power_off = intel_mid_power_off;
184 machine_ops.emergency_restart = intel_mid_reboot;
185
186 /* Avoid searching for BIOS MP tables */
187 x86_init.mpparse.find_smp_config = x86_init_noop;
188 x86_init.mpparse.get_smp_config = x86_init_uint_noop;
189 set_bit(MP_BUS_ISA, mp_bus_not_pci);
190 }
191
192 /*
193 * if user does not want to use per CPU apb timer, just give it a lower rating
194 * than local apic timer and skip the late per cpu timer init.
195 */
setup_x86_intel_mid_timer(char * arg)196 static inline int __init setup_x86_intel_mid_timer(char *arg)
197 {
198 if (!arg)
199 return -EINVAL;
200
201 if (strcmp("apbt_only", arg) == 0)
202 intel_mid_timer_options = INTEL_MID_TIMER_APBT_ONLY;
203 else if (strcmp("lapic_and_apbt", arg) == 0)
204 intel_mid_timer_options = INTEL_MID_TIMER_LAPIC_APBT;
205 else {
206 pr_warn("X86 INTEL_MID timer option %s not recognised use x86_intel_mid_timer=apbt_only or lapic_and_apbt\n",
207 arg);
208 return -EINVAL;
209 }
210 return 0;
211 }
212 __setup("x86_intel_mid_timer=", setup_x86_intel_mid_timer);
213