1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2015 Google, Inc
5 * Based on code from coreboot
13 #include <asm/cpu_x86.h>
15 #include <asm/lapic.h>
17 #include <asm/turbo.h>
19 #define BYT_PRV_CLK 0x800
20 #define BYT_PRV_CLK_EN (1 << 0)
21 #define BYT_PRV_CLK_M_VAL_SHIFT 1
22 #define BYT_PRV_CLK_N_VAL_SHIFT 16
23 #define BYT_PRV_CLK_UPDATE (1 << 31)
25 static void hsuart_clock_set(void *base)
30 * Configure the BayTrail UART clock for the internal HS UARTs
31 * (PCI devices) to 58982400 Hz
35 reg = (m << BYT_PRV_CLK_M_VAL_SHIFT) | (n << BYT_PRV_CLK_N_VAL_SHIFT);
36 writel(reg, base + BYT_PRV_CLK);
37 reg |= BYT_PRV_CLK_EN | BYT_PRV_CLK_UPDATE;
38 writel(reg, base + BYT_PRV_CLK);
42 * Configure the internal clock of both SIO HS-UARTs, if they are enabled
45 int arch_cpu_init_dm(void)
52 /* Loop over the 2 HS-UARTs */
53 for (i = 0; i < 2; i++) {
54 ret = dm_pci_bus_find_bdf(PCI_BDF(0, 0x1e, 3 + i), &dev);
56 base = dm_pci_map_bar(dev, PCI_BASE_ADDRESS_0,
58 hsuart_clock_set(base);
65 static void set_max_freq(void)
70 /* Enable speed step */
71 msr = msr_read(MSR_IA32_MISC_ENABLES);
73 msr_write(MSR_IA32_MISC_ENABLES, msr);
76 * Set guaranteed ratio [21:16] from IACORE_RATIOS to bits [15:8] of
79 msr = msr_read(MSR_IACORE_RATIOS);
80 perf_ctl.lo = (msr.lo & 0x3f0000) >> 8;
83 * Set guaranteed vid [21:16] from IACORE_VIDS to bits [7:0] of
86 msr = msr_read(MSR_IACORE_VIDS);
87 perf_ctl.lo |= (msr.lo & 0x7f0000) >> 16;
90 msr_write(MSR_IA32_PERF_CTL, perf_ctl);
93 static int cpu_x86_baytrail_probe(struct udevice *dev)
97 debug("Init BayTrail core\n");
100 * On BayTrail the turbo disable bit is actually scoped at the
101 * building-block level, not package. For non-BSP cores that are
102 * within a building block, enable turbo. The cores within the BSP's
103 * building block will just see it already enabled and move on.
108 /* Dynamic L2 shrink enable and threshold */
109 msr_clrsetbits_64(MSR_PMG_CST_CONFIG_CONTROL, 0x3f000f, 0xe0008),
112 msr_clrsetbits_64(MSR_POWER_CTL, 2, 0);
113 msr_setbits_64(MSR_POWER_MISC, 0x44);
115 /* Set this core to max frequency ratio */
121 static unsigned bus_freq(void)
123 msr_t clk_info = msr_read(MSR_BSEL_CR_OVERCLOCK_CONTROL);
124 switch (clk_info.lo & 0x3) {
138 static unsigned long tsc_freq(void)
141 ulong bclk = bus_freq();
146 platform_info = msr_read(MSR_PLATFORM_INFO);
148 return bclk * ((platform_info.lo >> 8) & 0xff);
151 static int baytrail_get_info(struct udevice *dev, struct cpu_info *info)
153 info->cpu_freq = tsc_freq();
154 info->features = 1 << CPU_FEAT_L1_CACHE | 1 << CPU_FEAT_MMU;
159 static int baytrail_get_count(struct udevice *dev)
164 * Use the algorithm described in Intel 64 and IA-32 Architectures
165 * Software Developer's Manual Volume 3 (3A, 3B & 3C): System
166 * Programming Guide, Jan-2015. Section 8.9.2: Hierarchical Mapping
167 * of CPUID Extended Topology Leaf.
170 struct cpuid_result leaf_b;
172 leaf_b = cpuid_ext(0xb, ecx);
175 * Bay Trail doesn't have hyperthreading so just determine the
176 * number of cores by from level type (ecx[15:8] == * 2)
178 if ((leaf_b.ecx & 0xff00) == 0x0200)
179 return leaf_b.ebx & 0xffff;
187 static const struct cpu_ops cpu_x86_baytrail_ops = {
188 .get_desc = cpu_x86_get_desc,
189 .get_info = baytrail_get_info,
190 .get_count = baytrail_get_count,
191 .get_vendor = cpu_x86_get_vendor,
194 static const struct udevice_id cpu_x86_baytrail_ids[] = {
195 { .compatible = "intel,baytrail-cpu" },
199 U_BOOT_DRIVER(cpu_x86_baytrail_drv) = {
200 .name = "cpu_x86_baytrail",
202 .of_match = cpu_x86_baytrail_ids,
203 .bind = cpu_x86_bind,
204 .probe = cpu_x86_baytrail_probe,
205 .ops = &cpu_x86_baytrail_ops,