xref: /openbmc/u-boot/arch/x86/cpu/baytrail/cpu.c (revision 6e87ae1c)
1 /*
2  * Copyright (C) 2015 Google, Inc
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  *
6  * Based on code from coreboot
7  */
8 
9 #include <common.h>
10 #include <cpu.h>
11 #include <dm.h>
12 #include <pci.h>
13 #include <asm/cpu.h>
14 #include <asm/cpu_x86.h>
15 #include <asm/io.h>
16 #include <asm/lapic.h>
17 #include <asm/msr.h>
18 #include <asm/turbo.h>
19 
20 #define BYT_PRV_CLK			0x800
21 #define BYT_PRV_CLK_EN			(1 << 0)
22 #define BYT_PRV_CLK_M_VAL_SHIFT		1
23 #define BYT_PRV_CLK_N_VAL_SHIFT		16
24 #define BYT_PRV_CLK_UPDATE		(1 << 31)
25 
26 static void hsuart_clock_set(void *base)
27 {
28 	u32 m, n, reg;
29 
30 	/*
31 	 * Configure the BayTrail UART clock for the internal HS UARTs
32 	 * (PCI devices) to 58982400 Hz
33 	 */
34 	m = 0x2400;
35 	n = 0x3d09;
36 	reg = (m << BYT_PRV_CLK_M_VAL_SHIFT) | (n << BYT_PRV_CLK_N_VAL_SHIFT);
37 	writel(reg, base + BYT_PRV_CLK);
38 	reg |= BYT_PRV_CLK_EN | BYT_PRV_CLK_UPDATE;
39 	writel(reg, base + BYT_PRV_CLK);
40 }
41 
42 /*
43  * Configure the internal clock of both SIO HS-UARTs, if they are enabled
44  * via FSP
45  */
46 int arch_cpu_init_dm(void)
47 {
48 	struct udevice *dev;
49 	void *base;
50 	int ret;
51 	int i;
52 
53 	/* Loop over the 2 HS-UARTs */
54 	for (i = 0; i < 2; i++) {
55 		ret = dm_pci_bus_find_bdf(PCI_BDF(0, 0x1e, 3 + i), &dev);
56 		if (!ret) {
57 			base = dm_pci_map_bar(dev, PCI_BASE_ADDRESS_0,
58 					      PCI_REGION_MEM);
59 			hsuart_clock_set(base);
60 		}
61 	}
62 
63 	return 0;
64 }
65 
66 static void set_max_freq(void)
67 {
68 	msr_t perf_ctl;
69 	msr_t msr;
70 
71 	/* Enable speed step */
72 	msr = msr_read(MSR_IA32_MISC_ENABLES);
73 	msr.lo |= (1 << 16);
74 	msr_write(MSR_IA32_MISC_ENABLES, msr);
75 
76 	/*
77 	 * Set guaranteed ratio [21:16] from IACORE_RATIOS to bits [15:8] of
78 	 * the PERF_CTL
79 	 */
80 	msr = msr_read(MSR_IACORE_RATIOS);
81 	perf_ctl.lo = (msr.lo & 0x3f0000) >> 8;
82 
83 	/*
84 	 * Set guaranteed vid [21:16] from IACORE_VIDS to bits [7:0] of
85 	 * the PERF_CTL
86 	 */
87 	msr = msr_read(MSR_IACORE_VIDS);
88 	perf_ctl.lo |= (msr.lo & 0x7f0000) >> 16;
89 	perf_ctl.hi = 0;
90 
91 	msr_write(MSR_IA32_PERF_CTL, perf_ctl);
92 }
93 
94 static int cpu_x86_baytrail_probe(struct udevice *dev)
95 {
96 	if (!ll_boot_init())
97 		return 0;
98 	debug("Init BayTrail core\n");
99 
100 	/*
101 	 * On BayTrail the turbo disable bit is actually scoped at the
102 	 * building-block level, not package. For non-BSP cores that are
103 	 * within a building block, enable turbo. The cores within the BSP's
104 	 * building block will just see it already enabled and move on.
105 	 */
106 	if (lapicid())
107 		turbo_enable();
108 
109 	/* Dynamic L2 shrink enable and threshold */
110 	msr_clrsetbits_64(MSR_PMG_CST_CONFIG_CONTROL, 0x3f000f, 0xe0008),
111 
112 	/* Disable C1E */
113 	msr_clrsetbits_64(MSR_POWER_CTL, 2, 0);
114 	msr_setbits_64(MSR_POWER_MISC, 0x44);
115 
116 	/* Set this core to max frequency ratio */
117 	set_max_freq();
118 
119 	return 0;
120 }
121 
122 static unsigned bus_freq(void)
123 {
124 	msr_t clk_info = msr_read(MSR_BSEL_CR_OVERCLOCK_CONTROL);
125 	switch (clk_info.lo & 0x3) {
126 	case 0:
127 		return 83333333;
128 	case 1:
129 		return 100000000;
130 	case 2:
131 		return 133333333;
132 	case 3:
133 		return 116666666;
134 	default:
135 		return 0;
136 	}
137 }
138 
139 static unsigned long tsc_freq(void)
140 {
141 	msr_t platform_info;
142 	ulong bclk = bus_freq();
143 
144 	if (!bclk)
145 		return 0;
146 
147 	platform_info = msr_read(MSR_PLATFORM_INFO);
148 
149 	return bclk * ((platform_info.lo >> 8) & 0xff);
150 }
151 
152 static int baytrail_get_info(struct udevice *dev, struct cpu_info *info)
153 {
154 	info->cpu_freq = tsc_freq();
155 	info->features = 1 << CPU_FEAT_L1_CACHE | 1 << CPU_FEAT_MMU;
156 
157 	return 0;
158 }
159 
160 static int baytrail_get_count(struct udevice *dev)
161 {
162 	int ecx = 0;
163 
164 	/*
165 	 * Use the algorithm described in Intel 64 and IA-32 Architectures
166 	 * Software Developer's Manual Volume 3 (3A, 3B & 3C): System
167 	 * Programming Guide, Jan-2015. Section 8.9.2: Hierarchical Mapping
168 	 * of CPUID Extended Topology Leaf.
169 	 */
170 	while (1) {
171 		struct cpuid_result leaf_b;
172 
173 		leaf_b = cpuid_ext(0xb, ecx);
174 
175 		/*
176 		 * Bay Trail doesn't have hyperthreading so just determine the
177 		 * number of cores by from level type (ecx[15:8] == * 2)
178 		 */
179 		if ((leaf_b.ecx & 0xff00) == 0x0200)
180 			return leaf_b.ebx & 0xffff;
181 
182 		ecx++;
183 	}
184 
185 	return 0;
186 }
187 
188 static const struct cpu_ops cpu_x86_baytrail_ops = {
189 	.get_desc	= cpu_x86_get_desc,
190 	.get_info	= baytrail_get_info,
191 	.get_count	= baytrail_get_count,
192 	.get_vendor	= cpu_x86_get_vendor,
193 };
194 
195 static const struct udevice_id cpu_x86_baytrail_ids[] = {
196 	{ .compatible = "intel,baytrail-cpu" },
197 	{ }
198 };
199 
200 U_BOOT_DRIVER(cpu_x86_baytrail_drv) = {
201 	.name		= "cpu_x86_baytrail",
202 	.id		= UCLASS_CPU,
203 	.of_match	= cpu_x86_baytrail_ids,
204 	.bind		= cpu_x86_bind,
205 	.probe		= cpu_x86_baytrail_probe,
206 	.ops		= &cpu_x86_baytrail_ops,
207 };
208