1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Amlogic Secure Monitor driver
4 *
5 * Copyright (C) 2016 Endless Mobile, Inc.
6 * Author: Carlo Caione <carlo@endlessm.com>
7 */
8
9 #define pr_fmt(fmt) "meson-sm: " fmt
10
11 #include <linux/arm-smccc.h>
12 #include <linux/bug.h>
13 #include <linux/io.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/of_device.h>
17 #include <linux/platform_device.h>
18 #include <linux/printk.h>
19 #include <linux/types.h>
20 #include <linux/sizes.h>
21 #include <linux/slab.h>
22
23 #include <linux/firmware/meson/meson_sm.h>
24
25 struct meson_sm_cmd {
26 unsigned int index;
27 u32 smc_id;
28 };
29 #define CMD(d, s) { .index = (d), .smc_id = (s), }
30
31 struct meson_sm_chip {
32 unsigned int shmem_size;
33 u32 cmd_shmem_in_base;
34 u32 cmd_shmem_out_base;
35 struct meson_sm_cmd cmd[];
36 };
37
38 static const struct meson_sm_chip gxbb_chip = {
39 .shmem_size = SZ_4K,
40 .cmd_shmem_in_base = 0x82000020,
41 .cmd_shmem_out_base = 0x82000021,
42 .cmd = {
43 CMD(SM_EFUSE_READ, 0x82000030),
44 CMD(SM_EFUSE_WRITE, 0x82000031),
45 CMD(SM_EFUSE_USER_MAX, 0x82000033),
46 CMD(SM_GET_CHIP_ID, 0x82000044),
47 CMD(SM_A1_PWRC_SET, 0x82000093),
48 CMD(SM_A1_PWRC_GET, 0x82000095),
49 { /* sentinel */ },
50 },
51 };
52
53 struct meson_sm_firmware {
54 const struct meson_sm_chip *chip;
55 void __iomem *sm_shmem_in_base;
56 void __iomem *sm_shmem_out_base;
57 };
58
meson_sm_get_cmd(const struct meson_sm_chip * chip,unsigned int cmd_index)59 static u32 meson_sm_get_cmd(const struct meson_sm_chip *chip,
60 unsigned int cmd_index)
61 {
62 const struct meson_sm_cmd *cmd = chip->cmd;
63
64 while (cmd->smc_id && cmd->index != cmd_index)
65 cmd++;
66
67 return cmd->smc_id;
68 }
69
__meson_sm_call(u32 cmd,u32 arg0,u32 arg1,u32 arg2,u32 arg3,u32 arg4)70 static u32 __meson_sm_call(u32 cmd, u32 arg0, u32 arg1, u32 arg2,
71 u32 arg3, u32 arg4)
72 {
73 struct arm_smccc_res res;
74
75 arm_smccc_smc(cmd, arg0, arg1, arg2, arg3, arg4, 0, 0, &res);
76 return res.a0;
77 }
78
meson_sm_map_shmem(u32 cmd_shmem,unsigned int size)79 static void __iomem *meson_sm_map_shmem(u32 cmd_shmem, unsigned int size)
80 {
81 u32 sm_phy_base;
82
83 sm_phy_base = __meson_sm_call(cmd_shmem, 0, 0, 0, 0, 0);
84 if (!sm_phy_base)
85 return 0;
86
87 return ioremap_cache(sm_phy_base, size);
88 }
89
90 /**
91 * meson_sm_call - generic SMC32 call to the secure-monitor
92 *
93 * @fw: Pointer to secure-monitor firmware
94 * @cmd_index: Index of the SMC32 function ID
95 * @ret: Returned value
96 * @arg0: SMC32 Argument 0
97 * @arg1: SMC32 Argument 1
98 * @arg2: SMC32 Argument 2
99 * @arg3: SMC32 Argument 3
100 * @arg4: SMC32 Argument 4
101 *
102 * Return: 0 on success, a negative value on error
103 */
meson_sm_call(struct meson_sm_firmware * fw,unsigned int cmd_index,u32 * ret,u32 arg0,u32 arg1,u32 arg2,u32 arg3,u32 arg4)104 int meson_sm_call(struct meson_sm_firmware *fw, unsigned int cmd_index,
105 u32 *ret, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
106 {
107 u32 cmd, lret;
108
109 if (!fw->chip)
110 return -ENOENT;
111
112 cmd = meson_sm_get_cmd(fw->chip, cmd_index);
113 if (!cmd)
114 return -EINVAL;
115
116 lret = __meson_sm_call(cmd, arg0, arg1, arg2, arg3, arg4);
117
118 if (ret)
119 *ret = lret;
120
121 return 0;
122 }
123 EXPORT_SYMBOL(meson_sm_call);
124
125 /**
126 * meson_sm_call_read - retrieve data from secure-monitor
127 *
128 * @fw: Pointer to secure-monitor firmware
129 * @buffer: Buffer to store the retrieved data
130 * @bsize: Size of the buffer
131 * @cmd_index: Index of the SMC32 function ID
132 * @arg0: SMC32 Argument 0
133 * @arg1: SMC32 Argument 1
134 * @arg2: SMC32 Argument 2
135 * @arg3: SMC32 Argument 3
136 * @arg4: SMC32 Argument 4
137 *
138 * Return: size of read data on success, a negative value on error
139 * When 0 is returned there is no guarantee about the amount of
140 * data read and bsize bytes are copied in buffer.
141 */
meson_sm_call_read(struct meson_sm_firmware * fw,void * buffer,unsigned int bsize,unsigned int cmd_index,u32 arg0,u32 arg1,u32 arg2,u32 arg3,u32 arg4)142 int meson_sm_call_read(struct meson_sm_firmware *fw, void *buffer,
143 unsigned int bsize, unsigned int cmd_index, u32 arg0,
144 u32 arg1, u32 arg2, u32 arg3, u32 arg4)
145 {
146 u32 size;
147 int ret;
148
149 if (!fw->chip)
150 return -ENOENT;
151
152 if (!fw->chip->cmd_shmem_out_base)
153 return -EINVAL;
154
155 if (bsize > fw->chip->shmem_size)
156 return -EINVAL;
157
158 if (meson_sm_call(fw, cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0)
159 return -EINVAL;
160
161 if (size > bsize)
162 return -EINVAL;
163
164 ret = size;
165
166 if (!size)
167 size = bsize;
168
169 if (buffer)
170 memcpy(buffer, fw->sm_shmem_out_base, size);
171
172 return ret;
173 }
174 EXPORT_SYMBOL(meson_sm_call_read);
175
176 /**
177 * meson_sm_call_write - send data to secure-monitor
178 *
179 * @fw: Pointer to secure-monitor firmware
180 * @buffer: Buffer containing data to send
181 * @size: Size of the data to send
182 * @cmd_index: Index of the SMC32 function ID
183 * @arg0: SMC32 Argument 0
184 * @arg1: SMC32 Argument 1
185 * @arg2: SMC32 Argument 2
186 * @arg3: SMC32 Argument 3
187 * @arg4: SMC32 Argument 4
188 *
189 * Return: size of sent data on success, a negative value on error
190 */
meson_sm_call_write(struct meson_sm_firmware * fw,void * buffer,unsigned int size,unsigned int cmd_index,u32 arg0,u32 arg1,u32 arg2,u32 arg3,u32 arg4)191 int meson_sm_call_write(struct meson_sm_firmware *fw, void *buffer,
192 unsigned int size, unsigned int cmd_index, u32 arg0,
193 u32 arg1, u32 arg2, u32 arg3, u32 arg4)
194 {
195 u32 written;
196
197 if (!fw->chip)
198 return -ENOENT;
199
200 if (size > fw->chip->shmem_size)
201 return -EINVAL;
202
203 if (!fw->chip->cmd_shmem_in_base)
204 return -EINVAL;
205
206 memcpy(fw->sm_shmem_in_base, buffer, size);
207
208 if (meson_sm_call(fw, cmd_index, &written, arg0, arg1, arg2, arg3, arg4) < 0)
209 return -EINVAL;
210
211 if (!written)
212 return -EINVAL;
213
214 return written;
215 }
216 EXPORT_SYMBOL(meson_sm_call_write);
217
218 /**
219 * meson_sm_get - get pointer to meson_sm_firmware structure.
220 *
221 * @sm_node: Pointer to the secure-monitor Device Tree node.
222 *
223 * Return: NULL is the secure-monitor device is not ready.
224 */
meson_sm_get(struct device_node * sm_node)225 struct meson_sm_firmware *meson_sm_get(struct device_node *sm_node)
226 {
227 struct platform_device *pdev = of_find_device_by_node(sm_node);
228
229 if (!pdev)
230 return NULL;
231
232 return platform_get_drvdata(pdev);
233 }
234 EXPORT_SYMBOL_GPL(meson_sm_get);
235
236 #define SM_CHIP_ID_LENGTH 119
237 #define SM_CHIP_ID_OFFSET 4
238 #define SM_CHIP_ID_SIZE 12
239
serial_show(struct device * dev,struct device_attribute * attr,char * buf)240 static ssize_t serial_show(struct device *dev, struct device_attribute *attr,
241 char *buf)
242 {
243 struct platform_device *pdev = to_platform_device(dev);
244 struct meson_sm_firmware *fw;
245 uint8_t *id_buf;
246 int ret;
247
248 fw = platform_get_drvdata(pdev);
249
250 id_buf = kmalloc(SM_CHIP_ID_LENGTH, GFP_KERNEL);
251 if (!id_buf)
252 return -ENOMEM;
253
254 ret = meson_sm_call_read(fw, id_buf, SM_CHIP_ID_LENGTH, SM_GET_CHIP_ID,
255 0, 0, 0, 0, 0);
256 if (ret < 0) {
257 kfree(id_buf);
258 return ret;
259 }
260
261 ret = sprintf(buf, "%12phN\n", &id_buf[SM_CHIP_ID_OFFSET]);
262
263 kfree(id_buf);
264
265 return ret;
266 }
267
268 static DEVICE_ATTR_RO(serial);
269
270 static struct attribute *meson_sm_sysfs_attributes[] = {
271 &dev_attr_serial.attr,
272 NULL,
273 };
274
275 static const struct attribute_group meson_sm_sysfs_attr_group = {
276 .attrs = meson_sm_sysfs_attributes,
277 };
278
279 static const struct of_device_id meson_sm_ids[] = {
280 { .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip },
281 { /* sentinel */ },
282 };
283
meson_sm_probe(struct platform_device * pdev)284 static int __init meson_sm_probe(struct platform_device *pdev)
285 {
286 struct device *dev = &pdev->dev;
287 const struct meson_sm_chip *chip;
288 struct meson_sm_firmware *fw;
289
290 fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL);
291 if (!fw)
292 return -ENOMEM;
293
294 chip = of_match_device(meson_sm_ids, dev)->data;
295 if (!chip)
296 return -EINVAL;
297
298 if (chip->cmd_shmem_in_base) {
299 fw->sm_shmem_in_base = meson_sm_map_shmem(chip->cmd_shmem_in_base,
300 chip->shmem_size);
301 if (WARN_ON(!fw->sm_shmem_in_base))
302 goto out;
303 }
304
305 if (chip->cmd_shmem_out_base) {
306 fw->sm_shmem_out_base = meson_sm_map_shmem(chip->cmd_shmem_out_base,
307 chip->shmem_size);
308 if (WARN_ON(!fw->sm_shmem_out_base))
309 goto out_in_base;
310 }
311
312 fw->chip = chip;
313
314 platform_set_drvdata(pdev, fw);
315
316 if (devm_of_platform_populate(dev))
317 goto out_in_base;
318
319 if (sysfs_create_group(&pdev->dev.kobj, &meson_sm_sysfs_attr_group))
320 goto out_in_base;
321
322 pr_info("secure-monitor enabled\n");
323
324 return 0;
325
326 out_in_base:
327 iounmap(fw->sm_shmem_in_base);
328 out:
329 return -EINVAL;
330 }
331
332 static struct platform_driver meson_sm_driver = {
333 .driver = {
334 .name = "meson-sm",
335 .of_match_table = of_match_ptr(meson_sm_ids),
336 },
337 };
338 module_platform_driver_probe(meson_sm_driver, meson_sm_probe);
339 MODULE_LICENSE("GPL v2");
340