1 // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
2 /*
3 * Freescale DPAA2 Platforms Console Driver
4 *
5 * Copyright 2015-2016 Freescale Semiconductor Inc.
6 * Copyright 2018 NXP
7 */
8
9 #define pr_fmt(fmt) "dpaa2-console: " fmt
10
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/of_address.h>
14 #include <linux/miscdevice.h>
15 #include <linux/platform_device.h>
16 #include <linux/uaccess.h>
17 #include <linux/slab.h>
18 #include <linux/fs.h>
19 #include <linux/io.h>
20
21 /* MC firmware base low/high registers indexes */
22 #define MCFBALR_OFFSET 0
23 #define MCFBAHR_OFFSET 1
24
25 /* Bit masks used to get the most/least significant part of the MC base addr */
26 #define MC_FW_ADDR_MASK_HIGH 0x1FFFF
27 #define MC_FW_ADDR_MASK_LOW 0xE0000000
28
29 #define MC_BUFFER_OFFSET 0x01000000
30 #define MC_BUFFER_SIZE (1024 * 1024 * 16)
31 #define MC_OFFSET_DELTA MC_BUFFER_OFFSET
32
33 #define AIOP_BUFFER_OFFSET 0x06000000
34 #define AIOP_BUFFER_SIZE (1024 * 1024 * 16)
35 #define AIOP_OFFSET_DELTA 0
36
37 #define LOG_HEADER_FLAG_BUFFER_WRAPAROUND 0x80000000
38 #define LAST_BYTE(a) ((a) & ~(LOG_HEADER_FLAG_BUFFER_WRAPAROUND))
39
40 /* MC and AIOP Magic words */
41 #define MAGIC_MC 0x4d430100
42 #define MAGIC_AIOP 0x41494F50
43
44 struct log_header {
45 __le32 magic_word;
46 char reserved[4];
47 __le32 buf_start;
48 __le32 buf_length;
49 __le32 last_byte;
50 };
51
52 struct console_data {
53 void __iomem *map_addr;
54 struct log_header __iomem *hdr;
55 void __iomem *start_addr;
56 void __iomem *end_addr;
57 void __iomem *end_of_data;
58 void __iomem *cur_ptr;
59 };
60
61 static struct resource mc_base_addr;
62
adjust_end(struct console_data * cd)63 static inline void adjust_end(struct console_data *cd)
64 {
65 u32 last_byte = readl(&cd->hdr->last_byte);
66
67 cd->end_of_data = cd->start_addr + LAST_BYTE(last_byte);
68 }
69
get_mc_fw_base_address(void)70 static u64 get_mc_fw_base_address(void)
71 {
72 u64 mcfwbase = 0ULL;
73 u32 __iomem *mcfbaregs;
74
75 mcfbaregs = ioremap(mc_base_addr.start, resource_size(&mc_base_addr));
76 if (!mcfbaregs) {
77 pr_err("could not map MC Firmware Base registers\n");
78 return 0;
79 }
80
81 mcfwbase = readl(mcfbaregs + MCFBAHR_OFFSET) &
82 MC_FW_ADDR_MASK_HIGH;
83 mcfwbase <<= 32;
84 mcfwbase |= readl(mcfbaregs + MCFBALR_OFFSET) & MC_FW_ADDR_MASK_LOW;
85 iounmap(mcfbaregs);
86
87 pr_debug("MC base address at 0x%016llx\n", mcfwbase);
88 return mcfwbase;
89 }
90
dpaa2_console_size(struct console_data * cd)91 static ssize_t dpaa2_console_size(struct console_data *cd)
92 {
93 ssize_t size;
94
95 if (cd->cur_ptr <= cd->end_of_data)
96 size = cd->end_of_data - cd->cur_ptr;
97 else
98 size = (cd->end_addr - cd->cur_ptr) +
99 (cd->end_of_data - cd->start_addr);
100
101 return size;
102 }
103
dpaa2_generic_console_open(struct inode * node,struct file * fp,u64 offset,u64 size,u32 expected_magic,u32 offset_delta)104 static int dpaa2_generic_console_open(struct inode *node, struct file *fp,
105 u64 offset, u64 size,
106 u32 expected_magic,
107 u32 offset_delta)
108 {
109 u32 read_magic, wrapped, last_byte, buf_start, buf_length;
110 struct console_data *cd;
111 u64 base_addr;
112 int err;
113
114 cd = kmalloc(sizeof(*cd), GFP_KERNEL);
115 if (!cd)
116 return -ENOMEM;
117
118 base_addr = get_mc_fw_base_address();
119 if (!base_addr) {
120 err = -EIO;
121 goto err_fwba;
122 }
123
124 cd->map_addr = ioremap(base_addr + offset, size);
125 if (!cd->map_addr) {
126 pr_err("cannot map console log memory\n");
127 err = -EIO;
128 goto err_ioremap;
129 }
130
131 cd->hdr = (struct log_header __iomem *)cd->map_addr;
132 read_magic = readl(&cd->hdr->magic_word);
133 last_byte = readl(&cd->hdr->last_byte);
134 buf_start = readl(&cd->hdr->buf_start);
135 buf_length = readl(&cd->hdr->buf_length);
136
137 if (read_magic != expected_magic) {
138 pr_warn("expected = %08x, read = %08x\n",
139 expected_magic, read_magic);
140 err = -EIO;
141 goto err_magic;
142 }
143
144 cd->start_addr = cd->map_addr + buf_start - offset_delta;
145 cd->end_addr = cd->start_addr + buf_length;
146
147 wrapped = last_byte & LOG_HEADER_FLAG_BUFFER_WRAPAROUND;
148
149 adjust_end(cd);
150 if (wrapped && cd->end_of_data != cd->end_addr)
151 cd->cur_ptr = cd->end_of_data + 1;
152 else
153 cd->cur_ptr = cd->start_addr;
154
155 fp->private_data = cd;
156
157 return 0;
158
159 err_magic:
160 iounmap(cd->map_addr);
161
162 err_ioremap:
163 err_fwba:
164 kfree(cd);
165
166 return err;
167 }
168
dpaa2_mc_console_open(struct inode * node,struct file * fp)169 static int dpaa2_mc_console_open(struct inode *node, struct file *fp)
170 {
171 return dpaa2_generic_console_open(node, fp,
172 MC_BUFFER_OFFSET, MC_BUFFER_SIZE,
173 MAGIC_MC, MC_OFFSET_DELTA);
174 }
175
dpaa2_aiop_console_open(struct inode * node,struct file * fp)176 static int dpaa2_aiop_console_open(struct inode *node, struct file *fp)
177 {
178 return dpaa2_generic_console_open(node, fp,
179 AIOP_BUFFER_OFFSET, AIOP_BUFFER_SIZE,
180 MAGIC_AIOP, AIOP_OFFSET_DELTA);
181 }
182
dpaa2_console_close(struct inode * node,struct file * fp)183 static int dpaa2_console_close(struct inode *node, struct file *fp)
184 {
185 struct console_data *cd = fp->private_data;
186
187 iounmap(cd->map_addr);
188 kfree(cd);
189 return 0;
190 }
191
dpaa2_console_read(struct file * fp,char __user * buf,size_t count,loff_t * f_pos)192 static ssize_t dpaa2_console_read(struct file *fp, char __user *buf,
193 size_t count, loff_t *f_pos)
194 {
195 struct console_data *cd = fp->private_data;
196 size_t bytes = dpaa2_console_size(cd);
197 size_t bytes_end = cd->end_addr - cd->cur_ptr;
198 size_t written = 0;
199 void *kbuf;
200 int err;
201
202 /* Check if we need to adjust the end of data addr */
203 adjust_end(cd);
204
205 if (cd->end_of_data == cd->cur_ptr)
206 return 0;
207
208 if (count < bytes)
209 bytes = count;
210
211 kbuf = kmalloc(bytes, GFP_KERNEL);
212 if (!kbuf)
213 return -ENOMEM;
214
215 if (bytes > bytes_end) {
216 memcpy_fromio(kbuf, cd->cur_ptr, bytes_end);
217 if (copy_to_user(buf, kbuf, bytes_end)) {
218 err = -EFAULT;
219 goto err_free_buf;
220 }
221 buf += bytes_end;
222 cd->cur_ptr = cd->start_addr;
223 bytes -= bytes_end;
224 written += bytes_end;
225 }
226
227 memcpy_fromio(kbuf, cd->cur_ptr, bytes);
228 if (copy_to_user(buf, kbuf, bytes)) {
229 err = -EFAULT;
230 goto err_free_buf;
231 }
232 cd->cur_ptr += bytes;
233 written += bytes;
234
235 kfree(kbuf);
236 return written;
237
238 err_free_buf:
239 kfree(kbuf);
240
241 return err;
242 }
243
244 static const struct file_operations dpaa2_mc_console_fops = {
245 .owner = THIS_MODULE,
246 .open = dpaa2_mc_console_open,
247 .release = dpaa2_console_close,
248 .read = dpaa2_console_read,
249 };
250
251 static struct miscdevice dpaa2_mc_console_dev = {
252 .minor = MISC_DYNAMIC_MINOR,
253 .name = "dpaa2_mc_console",
254 .fops = &dpaa2_mc_console_fops
255 };
256
257 static const struct file_operations dpaa2_aiop_console_fops = {
258 .owner = THIS_MODULE,
259 .open = dpaa2_aiop_console_open,
260 .release = dpaa2_console_close,
261 .read = dpaa2_console_read,
262 };
263
264 static struct miscdevice dpaa2_aiop_console_dev = {
265 .minor = MISC_DYNAMIC_MINOR,
266 .name = "dpaa2_aiop_console",
267 .fops = &dpaa2_aiop_console_fops
268 };
269
dpaa2_console_probe(struct platform_device * pdev)270 static int dpaa2_console_probe(struct platform_device *pdev)
271 {
272 int error;
273
274 error = of_address_to_resource(pdev->dev.of_node, 0, &mc_base_addr);
275 if (error < 0) {
276 pr_err("of_address_to_resource() failed for %pOF with %d\n",
277 pdev->dev.of_node, error);
278 return error;
279 }
280
281 error = misc_register(&dpaa2_mc_console_dev);
282 if (error) {
283 pr_err("cannot register device %s\n",
284 dpaa2_mc_console_dev.name);
285 goto err_register_mc;
286 }
287
288 error = misc_register(&dpaa2_aiop_console_dev);
289 if (error) {
290 pr_err("cannot register device %s\n",
291 dpaa2_aiop_console_dev.name);
292 goto err_register_aiop;
293 }
294
295 return 0;
296
297 err_register_aiop:
298 misc_deregister(&dpaa2_mc_console_dev);
299 err_register_mc:
300 return error;
301 }
302
dpaa2_console_remove(struct platform_device * pdev)303 static void dpaa2_console_remove(struct platform_device *pdev)
304 {
305 misc_deregister(&dpaa2_mc_console_dev);
306 misc_deregister(&dpaa2_aiop_console_dev);
307 }
308
309 static const struct of_device_id dpaa2_console_match_table[] = {
310 { .compatible = "fsl,dpaa2-console",},
311 {},
312 };
313
314 MODULE_DEVICE_TABLE(of, dpaa2_console_match_table);
315
316 static struct platform_driver dpaa2_console_driver = {
317 .driver = {
318 .name = "dpaa2-console",
319 .pm = NULL,
320 .of_match_table = dpaa2_console_match_table,
321 },
322 .probe = dpaa2_console_probe,
323 .remove_new = dpaa2_console_remove,
324 };
325 module_platform_driver(dpaa2_console_driver);
326
327 MODULE_LICENSE("Dual BSD/GPL");
328 MODULE_AUTHOR("Roy Pledge <roy.pledge@nxp.com>");
329 MODULE_DESCRIPTION("DPAA2 console driver");
330