1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * PCI emulation device for an x86 Primary-to-Sideband bus
4 *
5 * Copyright 2019 Google LLC
6 * Written by Simon Glass <sjg@chromium.org>
7 */
8
9 #define LOG_CATEGORY UCLASS_MISC
10
11 #include <common.h>
12 #include <axi.h>
13 #include <dm.h>
14 #include <log.h>
15 #include <pci.h>
16 #include <asm/test.h>
17 #include <p2sb.h>
18
19 /**
20 * struct p2sb_emul_plat - platform data for this device
21 *
22 * @command: Current PCI command value
23 * @bar: Current base address values
24 */
25 struct p2sb_emul_plat {
26 u16 command;
27 u32 bar[6];
28 };
29
30 enum {
31 /* This emulator supports 16 different devices */
32 MEMMAP_SIZE = 16 << PCR_PORTID_SHIFT,
33 };
34
35 static struct pci_bar {
36 int type;
37 u32 size;
38 } barinfo[] = {
39 { PCI_BASE_ADDRESS_MEM_TYPE_32, MEMMAP_SIZE },
40 { 0, 0 },
41 { 0, 0 },
42 { 0, 0 },
43 { 0, 0 },
44 { 0, 0 },
45 };
46
47 struct p2sb_emul_priv {
48 u8 regs[16];
49 };
50
sandbox_p2sb_emul_read_config(const struct udevice * emul,uint offset,ulong * valuep,enum pci_size_t size)51 static int sandbox_p2sb_emul_read_config(const struct udevice *emul,
52 uint offset, ulong *valuep,
53 enum pci_size_t size)
54 {
55 struct p2sb_emul_plat *plat = dev_get_plat(emul);
56
57 switch (offset) {
58 case PCI_COMMAND:
59 *valuep = plat->command;
60 break;
61 case PCI_HEADER_TYPE:
62 *valuep = PCI_HEADER_TYPE_NORMAL;
63 break;
64 case PCI_VENDOR_ID:
65 *valuep = SANDBOX_PCI_VENDOR_ID;
66 break;
67 case PCI_DEVICE_ID:
68 *valuep = SANDBOX_PCI_P2SB_EMUL_ID;
69 break;
70 case PCI_CLASS_DEVICE:
71 if (size == PCI_SIZE_8) {
72 *valuep = SANDBOX_PCI_CLASS_SUB_CODE;
73 } else {
74 *valuep = (SANDBOX_PCI_CLASS_CODE << 8) |
75 SANDBOX_PCI_CLASS_SUB_CODE;
76 }
77 break;
78 case PCI_CLASS_CODE:
79 *valuep = SANDBOX_PCI_CLASS_CODE;
80 break;
81 case PCI_BASE_ADDRESS_0:
82 case PCI_BASE_ADDRESS_1:
83 case PCI_BASE_ADDRESS_2:
84 case PCI_BASE_ADDRESS_3:
85 case PCI_BASE_ADDRESS_4:
86 case PCI_BASE_ADDRESS_5: {
87 int barnum;
88 u32 *bar;
89
90 barnum = pci_offset_to_barnum(offset);
91 bar = &plat->bar[barnum];
92
93 *valuep = sandbox_pci_read_bar(*bar, barinfo[barnum].type,
94 barinfo[barnum].size);
95 break;
96 }
97 case PCI_CAPABILITY_LIST:
98 *valuep = PCI_CAP_ID_PM_OFFSET;
99 break;
100 }
101
102 return 0;
103 }
104
sandbox_p2sb_emul_write_config(struct udevice * emul,uint offset,ulong value,enum pci_size_t size)105 static int sandbox_p2sb_emul_write_config(struct udevice *emul, uint offset,
106 ulong value, enum pci_size_t size)
107 {
108 struct p2sb_emul_plat *plat = dev_get_plat(emul);
109
110 switch (offset) {
111 case PCI_COMMAND:
112 plat->command = value;
113 break;
114 case PCI_BASE_ADDRESS_0:
115 case PCI_BASE_ADDRESS_1: {
116 int barnum;
117 u32 *bar;
118
119 barnum = pci_offset_to_barnum(offset);
120 bar = &plat->bar[barnum];
121
122 log_debug("w bar %d=%lx\n", barnum, value);
123 *bar = value;
124 /* space indicator (bit#0) is read-only */
125 *bar |= barinfo[barnum].type;
126 break;
127 }
128 }
129
130 return 0;
131 }
132
sandbox_p2sb_emul_find_bar(struct udevice * emul,unsigned int addr,int * barnump,unsigned int * offsetp)133 static int sandbox_p2sb_emul_find_bar(struct udevice *emul, unsigned int addr,
134 int *barnump, unsigned int *offsetp)
135 {
136 struct p2sb_emul_plat *plat = dev_get_plat(emul);
137 int barnum;
138
139 for (barnum = 0; barnum < ARRAY_SIZE(barinfo); barnum++) {
140 unsigned int size = barinfo[barnum].size;
141 u32 base = plat->bar[barnum] & ~PCI_BASE_ADDRESS_SPACE;
142
143 if (addr >= base && addr < base + size) {
144 *barnump = barnum;
145 *offsetp = addr - base;
146 return 0;
147 }
148 }
149 *barnump = -1;
150
151 return -ENOENT;
152 }
153
sandbox_p2sb_emul_read_io(struct udevice * dev,unsigned int addr,ulong * valuep,enum pci_size_t size)154 static int sandbox_p2sb_emul_read_io(struct udevice *dev, unsigned int addr,
155 ulong *valuep, enum pci_size_t size)
156 {
157 unsigned int offset;
158 int barnum;
159 int ret;
160
161 ret = sandbox_p2sb_emul_find_bar(dev, addr, &barnum, &offset);
162 if (ret)
163 return ret;
164
165 if (barnum == 4)
166 *valuep = offset;
167 else if (barnum == 0)
168 *valuep = offset;
169
170 return 0;
171 }
172
sandbox_p2sb_emul_write_io(struct udevice * dev,unsigned int addr,ulong value,enum pci_size_t size)173 static int sandbox_p2sb_emul_write_io(struct udevice *dev, unsigned int addr,
174 ulong value, enum pci_size_t size)
175 {
176 unsigned int offset;
177 int barnum;
178 int ret;
179
180 ret = sandbox_p2sb_emul_find_bar(dev, addr, &barnum, &offset);
181 if (ret)
182 return ret;
183
184 return 0;
185 }
186
find_p2sb_channel(struct udevice * emul,uint offset,struct udevice ** devp)187 static int find_p2sb_channel(struct udevice *emul, uint offset,
188 struct udevice **devp)
189 {
190 uint pid = offset >> PCR_PORTID_SHIFT;
191 struct udevice *p2sb, *dev;
192 int ret;
193
194 ret = sandbox_pci_get_client(emul, &p2sb);
195 if (ret)
196 return log_msg_ret("No client", ret);
197
198 device_foreach_child(dev, p2sb) {
199 struct p2sb_child_plat *pplat =
200 dev_get_parent_plat(dev);
201
202 log_debug(" - child %s, pid %d, want %d\n", dev->name,
203 pplat->pid, pid);
204 if (pid == pplat->pid) {
205 *devp = dev;
206 return 0;
207 }
208 }
209
210 return -ENOENT;
211 }
212
sandbox_p2sb_emul_map_physmem(struct udevice * dev,phys_addr_t addr,unsigned long * lenp,void ** ptrp)213 static int sandbox_p2sb_emul_map_physmem(struct udevice *dev,
214 phys_addr_t addr, unsigned long *lenp,
215 void **ptrp)
216 {
217 struct p2sb_emul_priv *priv = dev_get_priv(dev);
218 struct udevice *child = NULL; /* Silence compiler warning */
219 unsigned int offset;
220 int barnum;
221 int ret;
222
223 log_debug("map %x: ", (uint)addr);
224 ret = sandbox_p2sb_emul_find_bar(dev, addr, &barnum, &offset);
225 if (ret)
226 return log_msg_ret("Cannot find bar", ret);
227 log_debug("bar %d, offset %x\n", barnum, offset);
228
229 if (barnum != 0)
230 return log_msg_ret("Unknown BAR", -EINVAL);
231
232 ret = find_p2sb_channel(dev, offset, &child);
233 if (ret)
234 return log_msg_ret("Cannot find channel", ret);
235
236 offset &= ((1 << PCR_PORTID_SHIFT) - 1);
237 ret = axi_read(child, offset, priv->regs, AXI_SIZE_32);
238 if (ret)
239 return log_msg_ret("Child read failed", ret);
240 *ptrp = priv->regs + (offset & 3);
241 *lenp = 4;
242
243 return 0;
244 }
245
246 static struct dm_pci_emul_ops sandbox_p2sb_emul_emul_ops = {
247 .read_config = sandbox_p2sb_emul_read_config,
248 .write_config = sandbox_p2sb_emul_write_config,
249 .read_io = sandbox_p2sb_emul_read_io,
250 .write_io = sandbox_p2sb_emul_write_io,
251 .map_physmem = sandbox_p2sb_emul_map_physmem,
252 };
253
254 static const struct udevice_id sandbox_p2sb_emul_ids[] = {
255 { .compatible = "sandbox,p2sb-emul" },
256 { }
257 };
258
259 U_BOOT_DRIVER(sandbox_p2sb_emul_emul) = {
260 .name = "sandbox_p2sb_emul_emul",
261 .id = UCLASS_PCI_EMUL,
262 .of_match = sandbox_p2sb_emul_ids,
263 .ops = &sandbox_p2sb_emul_emul_ops,
264 .priv_auto = sizeof(struct p2sb_emul_priv),
265 .plat_auto = sizeof(struct p2sb_emul_plat),
266 };
267
268 static struct pci_device_id sandbox_p2sb_emul_supported[] = {
269 { PCI_VDEVICE(SANDBOX, SANDBOX_PCI_PMC_EMUL_ID) },
270 {},
271 };
272
273 U_BOOT_PCI_DEVICE(sandbox_p2sb_emul_emul, sandbox_p2sb_emul_supported);
274