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_device.h>
13 #include <linux/of_address.h>
14 #include <linux/miscdevice.h>
15 #include <linux/uaccess.h>
16 #include <linux/slab.h>
17 #include <linux/fs.h>
18 #include <linux/io.h>
19
20 /* MC firmware base low/high registers indexes */
21 #define MCFBALR_OFFSET 0
22 #define MCFBAHR_OFFSET 1
23
24 /* Bit masks used to get the most/least significant part of the MC base addr */
25 #define MC_FW_ADDR_MASK_HIGH 0x1FFFF
26 #define MC_FW_ADDR_MASK_LOW 0xE0000000
27
28 #define MC_BUFFER_OFFSET 0x01000000
29 #define MC_BUFFER_SIZE (1024 * 1024 * 16)
30 #define MC_OFFSET_DELTA MC_BUFFER_OFFSET
31
32 #define AIOP_BUFFER_OFFSET 0x06000000
33 #define AIOP_BUFFER_SIZE (1024 * 1024 * 16)
34 #define AIOP_OFFSET_DELTA 0
35
36 #define LOG_HEADER_FLAG_BUFFER_WRAPAROUND 0x80000000
37 #define LAST_BYTE(a) ((a) & ~(LOG_HEADER_FLAG_BUFFER_WRAPAROUND))
38
39 /* MC and AIOP Magic words */
40 #define MAGIC_MC 0x4d430100
41 #define MAGIC_AIOP 0x41494F50
42
43 struct log_header {
44 __le32 magic_word;
45 char reserved[4];
46 __le32 buf_start;
47 __le32 buf_length;
48 __le32 last_byte;
49 };
50
51 struct console_data {
52 void __iomem *map_addr;
53 struct log_header __iomem *hdr;
54 void __iomem *start_addr;
55 void __iomem *end_addr;
56 void __iomem *end_of_data;
57 void __iomem *cur_ptr;
58 };
59
60 static struct resource mc_base_addr;
61
adjust_end(struct console_data * cd)62 static inline void adjust_end(struct console_data *cd)
63 {
64 u32 last_byte = readl(&cd->hdr->last_byte);
65
66 cd->end_of_data = cd->start_addr + LAST_BYTE(last_byte);
67 }
68
get_mc_fw_base_address(void)69 static u64 get_mc_fw_base_address(void)
70 {
71 u64 mcfwbase = 0ULL;
72 u32 __iomem *mcfbaregs;
73
74 mcfbaregs = ioremap(mc_base_addr.start, resource_size(&mc_base_addr));
75 if (!mcfbaregs) {
76 pr_err("could not map MC Firmware Base registers\n");
77 return 0;
78 }
79
80 mcfwbase = readl(mcfbaregs + MCFBAHR_OFFSET) &
81 MC_FW_ADDR_MASK_HIGH;
82 mcfwbase <<= 32;
83 mcfwbase |= readl(mcfbaregs + MCFBALR_OFFSET) & MC_FW_ADDR_MASK_LOW;
84 iounmap(mcfbaregs);
85
86 pr_debug("MC base address at 0x%016llx\n", mcfwbase);
87 return mcfwbase;
88 }
89
dpaa2_console_size(struct console_data * cd)90 static ssize_t dpaa2_console_size(struct console_data *cd)
91 {
92 ssize_t size;
93
94 if (cd->cur_ptr <= cd->end_of_data)
95 size = cd->end_of_data - cd->cur_ptr;
96 else
97 size = (cd->end_addr - cd->cur_ptr) +
98 (cd->end_of_data - cd->start_addr);
99
100 return size;
101 }
102
dpaa2_generic_console_open(struct inode * node,struct file * fp,u64 offset,u64 size,u32 expected_magic,u32 offset_delta)103 static int dpaa2_generic_console_open(struct inode *node, struct file *fp,
104 u64 offset, u64 size,
105 u32 expected_magic,
106 u32 offset_delta)
107 {
108 u32 read_magic, wrapped, last_byte, buf_start, buf_length;
109 struct console_data *cd;
110 u64 base_addr;
111 int err;
112
113 cd = kmalloc(sizeof(*cd), GFP_KERNEL);
114 if (!cd)
115 return -ENOMEM;
116
117 base_addr = get_mc_fw_base_address();
118 if (!base_addr) {
119 err = -EIO;
120 goto err_fwba;
121 }
122
123 cd->map_addr = ioremap(base_addr + offset, size);
124 if (!cd->map_addr) {
125 pr_err("cannot map console log memory\n");
126 err = -EIO;
127 goto err_ioremap;
128 }
129
130 cd->hdr = (struct log_header __iomem *)cd->map_addr;
131 read_magic = readl(&cd->hdr->magic_word);
132 last_byte = readl(&cd->hdr->last_byte);
133 buf_start = readl(&cd->hdr->buf_start);
134 buf_length = readl(&cd->hdr->buf_length);
135
136 if (read_magic != expected_magic) {
137 pr_warn("expected = %08x, read = %08x\n",
138 expected_magic, read_magic);
139 err = -EIO;
140 goto err_magic;
141 }
142
143 cd->start_addr = cd->map_addr + buf_start - offset_delta;
144 cd->end_addr = cd->start_addr + buf_length;
145
146 wrapped = last_byte & LOG_HEADER_FLAG_BUFFER_WRAPAROUND;
147
148 adjust_end(cd);
149 if (wrapped && cd->end_of_data != cd->end_addr)
150 cd->cur_ptr = cd->end_of_data + 1;
151 else
152 cd->cur_ptr = cd->start_addr;
153
154 fp->private_data = cd;
155
156 return 0;
157
158 err_magic:
159 iounmap(cd->map_addr);
160
161 err_ioremap:
162 err_fwba:
163 kfree(cd);
164
165 return err;
166 }
167
dpaa2_mc_console_open(struct inode * node,struct file * fp)168 static int dpaa2_mc_console_open(struct inode *node, struct file *fp)
169 {
170 return dpaa2_generic_console_open(node, fp,
171 MC_BUFFER_OFFSET, MC_BUFFER_SIZE,
172 MAGIC_MC, MC_OFFSET_DELTA);
173 }
174
dpaa2_aiop_console_open(struct inode * node,struct file * fp)175 static int dpaa2_aiop_console_open(struct inode *node, struct file *fp)
176 {
177 return dpaa2_generic_console_open(node, fp,
178 AIOP_BUFFER_OFFSET, AIOP_BUFFER_SIZE,
179 MAGIC_AIOP, AIOP_OFFSET_DELTA);
180 }
181
dpaa2_console_close(struct inode * node,struct file * fp)182 static int dpaa2_console_close(struct inode *node, struct file *fp)
183 {
184 struct console_data *cd = fp->private_data;
185
186 iounmap(cd->map_addr);
187 kfree(cd);
188 return 0;
189 }
190
dpaa2_console_read(struct file * fp,char __user * buf,size_t count,loff_t * f_pos)191 static ssize_t dpaa2_console_read(struct file *fp, char __user *buf,
192 size_t count, loff_t *f_pos)
193 {
194 struct console_data *cd = fp->private_data;
195 size_t bytes = dpaa2_console_size(cd);
196 size_t bytes_end = cd->end_addr - cd->cur_ptr;
197 size_t written = 0;
198 void *kbuf;
199 int err;
200
201 /* Check if we need to adjust the end of data addr */
202 adjust_end(cd);
203
204 if (cd->end_of_data == cd->cur_ptr)
205 return 0;
206
207 if (count < bytes)
208 bytes = count;
209
210 kbuf = kmalloc(bytes, GFP_KERNEL);
211 if (!kbuf)
212 return -ENOMEM;
213
214 if (bytes > bytes_end) {
215 memcpy_fromio(kbuf, cd->cur_ptr, bytes_end);
216 if (copy_to_user(buf, kbuf, bytes_end)) {
217 err = -EFAULT;
218 goto err_free_buf;
219 }
220 buf += bytes_end;
221 cd->cur_ptr = cd->start_addr;
222 bytes -= bytes_end;
223 written += bytes_end;
224 }
225
226 memcpy_fromio(kbuf, cd->cur_ptr, bytes);
227 if (copy_to_user(buf, kbuf, bytes)) {
228 err = -EFAULT;
229 goto err_free_buf;
230 }
231 cd->cur_ptr += bytes;
232 written += bytes;
233
234 kfree(kbuf);
235 return written;
236
237 err_free_buf:
238 kfree(kbuf);
239
240 return err;
241 }
242
243 static const struct file_operations dpaa2_mc_console_fops = {
244 .owner = THIS_MODULE,
245 .open = dpaa2_mc_console_open,
246 .release = dpaa2_console_close,
247 .read = dpaa2_console_read,
248 };
249
250 static struct miscdevice dpaa2_mc_console_dev = {
251 .minor = MISC_DYNAMIC_MINOR,
252 .name = "dpaa2_mc_console",
253 .fops = &dpaa2_mc_console_fops
254 };
255
256 static const struct file_operations dpaa2_aiop_console_fops = {
257 .owner = THIS_MODULE,
258 .open = dpaa2_aiop_console_open,
259 .release = dpaa2_console_close,
260 .read = dpaa2_console_read,
261 };
262
263 static struct miscdevice dpaa2_aiop_console_dev = {
264 .minor = MISC_DYNAMIC_MINOR,
265 .name = "dpaa2_aiop_console",
266 .fops = &dpaa2_aiop_console_fops
267 };
268
dpaa2_console_probe(struct platform_device * pdev)269 static int dpaa2_console_probe(struct platform_device *pdev)
270 {
271 int error;
272
273 error = of_address_to_resource(pdev->dev.of_node, 0, &mc_base_addr);
274 if (error < 0) {
275 pr_err("of_address_to_resource() failed for %pOF with %d\n",
276 pdev->dev.of_node, error);
277 return error;
278 }
279
280 error = misc_register(&dpaa2_mc_console_dev);
281 if (error) {
282 pr_err("cannot register device %s\n",
283 dpaa2_mc_console_dev.name);
284 goto err_register_mc;
285 }
286
287 error = misc_register(&dpaa2_aiop_console_dev);
288 if (error) {
289 pr_err("cannot register device %s\n",
290 dpaa2_aiop_console_dev.name);
291 goto err_register_aiop;
292 }
293
294 return 0;
295
296 err_register_aiop:
297 misc_deregister(&dpaa2_mc_console_dev);
298 err_register_mc:
299 return error;
300 }
301
dpaa2_console_remove(struct platform_device * pdev)302 static int dpaa2_console_remove(struct platform_device *pdev)
303 {
304 misc_deregister(&dpaa2_mc_console_dev);
305 misc_deregister(&dpaa2_aiop_console_dev);
306
307 return 0;
308 }
309
310 static const struct of_device_id dpaa2_console_match_table[] = {
311 { .compatible = "fsl,dpaa2-console",},
312 {},
313 };
314
315 MODULE_DEVICE_TABLE(of, dpaa2_console_match_table);
316
317 static struct platform_driver dpaa2_console_driver = {
318 .driver = {
319 .name = "dpaa2-console",
320 .pm = NULL,
321 .of_match_table = dpaa2_console_match_table,
322 },
323 .probe = dpaa2_console_probe,
324 .remove = dpaa2_console_remove,
325 };
326 module_platform_driver(dpaa2_console_driver);
327
328 MODULE_LICENSE("Dual BSD/GPL");
329 MODULE_AUTHOR("Roy Pledge <roy.pledge@nxp.com>");
330 MODULE_DESCRIPTION("DPAA2 console driver");
331