1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
4 * Copyright (C) 2020, Sean Anderson <seanga2@gmail.com>
5 */
6
7 #include <clk.h>
8 #include <common.h>
9 #include <cpu.h>
10 #include <dm.h>
11 #include <errno.h>
12 #include <log.h>
13 #include <asm/global_data.h>
14 #include <dm/device-internal.h>
15 #include <dm/lists.h>
16 #include <linux/bitops.h>
17 #include <linux/err.h>
18
19 DECLARE_GLOBAL_DATA_PTR;
20
riscv_cpu_get_desc(const struct udevice * dev,char * buf,int size)21 static int riscv_cpu_get_desc(const struct udevice *dev, char *buf, int size)
22 {
23 const char *isa;
24
25 isa = dev_read_string(dev, "riscv,isa");
26 if (size < (strlen(isa) + 1))
27 return -ENOSPC;
28
29 strcpy(buf, isa);
30
31 return 0;
32 }
33
riscv_cpu_get_info(const struct udevice * dev,struct cpu_info * info)34 static int riscv_cpu_get_info(const struct udevice *dev, struct cpu_info *info)
35 {
36 int ret;
37 struct clk clk;
38 const char *mmu;
39 u32 i_cache_size;
40 u32 d_cache_size;
41
42 /* First try getting the frequency from the assigned clock */
43 ret = clk_get_by_index((struct udevice *)dev, 0, &clk);
44 if (!ret) {
45 ret = clk_get_rate(&clk);
46 if (!IS_ERR_VALUE(ret))
47 info->cpu_freq = ret;
48 clk_free(&clk);
49 }
50
51 if (!info->cpu_freq)
52 dev_read_u32(dev, "clock-frequency", (u32 *)&info->cpu_freq);
53
54 mmu = dev_read_string(dev, "mmu-type");
55 if (mmu)
56 info->features |= BIT(CPU_FEAT_MMU);
57
58 /* check if I cache is present */
59 ret = dev_read_u32(dev, "i-cache-size", &i_cache_size);
60 if (ret)
61 /* if not found check if d-cache is present */
62 ret = dev_read_u32(dev, "d-cache-size", &d_cache_size);
63
64 /* if either I or D cache is present set L1 cache feature */
65 if (!ret)
66 info->features |= BIT(CPU_FEAT_L1_CACHE);
67
68 return 0;
69 }
70
riscv_cpu_get_count(const struct udevice * dev)71 static int riscv_cpu_get_count(const struct udevice *dev)
72 {
73 ofnode node;
74 int num = 0;
75
76 ofnode_for_each_subnode(node, dev_ofnode(dev->parent)) {
77 const char *device_type;
78
79 /* skip if hart is marked as not available in the device tree */
80 if (!ofnode_is_available(node))
81 continue;
82
83 device_type = ofnode_read_string(node, "device_type");
84 if (!device_type)
85 continue;
86 if (strcmp(device_type, "cpu") == 0)
87 num++;
88 }
89
90 return num;
91 }
92
riscv_cpu_bind(struct udevice * dev)93 static int riscv_cpu_bind(struct udevice *dev)
94 {
95 struct cpu_plat *plat = dev_get_parent_plat(dev);
96 struct driver *drv;
97 int ret;
98
99 /* save the hart id */
100 plat->cpu_id = dev_read_addr(dev);
101 /* first examine the property in current cpu node */
102 ret = dev_read_u32(dev, "timebase-frequency", &plat->timebase_freq);
103 /* if not found, then look at the parent /cpus node */
104 if (ret)
105 dev_read_u32(dev->parent, "timebase-frequency",
106 &plat->timebase_freq);
107
108 /*
109 * Bind riscv-timer driver on boot hart.
110 *
111 * We only instantiate one timer device which is enough for U-Boot.
112 * Pass the "timebase-frequency" value as the driver data for the
113 * timer device.
114 *
115 * Return value is not checked since it's possible that the timer
116 * driver is not included.
117 */
118 if (plat->cpu_id == gd->arch.boot_hart && plat->timebase_freq) {
119 drv = lists_driver_lookup_name("riscv_timer");
120 if (!drv) {
121 debug("Cannot find the timer driver, not included?\n");
122 return 0;
123 }
124
125 device_bind_with_driver_data(dev, drv, "riscv_timer",
126 plat->timebase_freq, ofnode_null(),
127 NULL);
128 }
129
130 return 0;
131 }
132
riscv_cpu_probe(struct udevice * dev)133 static int riscv_cpu_probe(struct udevice *dev)
134 {
135 int ret = 0;
136 struct clk clk;
137
138 /* Get a clock if it exists */
139 ret = clk_get_by_index(dev, 0, &clk);
140 if (ret)
141 return 0;
142
143 ret = clk_enable(&clk);
144 clk_free(&clk);
145 if (ret == -ENOSYS || ret == -ENOTSUPP)
146 return 0;
147 else
148 return ret;
149 }
150
151 static const struct cpu_ops riscv_cpu_ops = {
152 .get_desc = riscv_cpu_get_desc,
153 .get_info = riscv_cpu_get_info,
154 .get_count = riscv_cpu_get_count,
155 };
156
157 static const struct udevice_id riscv_cpu_ids[] = {
158 { .compatible = "riscv" },
159 { }
160 };
161
162 U_BOOT_DRIVER(riscv_cpu) = {
163 .name = "riscv_cpu",
164 .id = UCLASS_CPU,
165 .of_match = riscv_cpu_ids,
166 .bind = riscv_cpu_bind,
167 .probe = riscv_cpu_probe,
168 .ops = &riscv_cpu_ops,
169 .flags = DM_FLAG_PRE_RELOC,
170 };
171