Commit | Line | Data |
---|---|---|
666b7793 AH |
1 | /* |
2 | * Copyright (C) 2007 Google, Inc. | |
3 | * Copyright (C) 2012 Intel, Inc. | |
3840ed95 | 4 | * Copyright (C) 2017 Imagination Technologies Ltd. |
666b7793 AH |
5 | * |
6 | * This software is licensed under the terms of the GNU General Public | |
7 | * License version 2, as published by the Free Software Foundation, and | |
8 | * may be copied, distributed, and modified under those terms. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | */ | |
16 | ||
17 | #include <linux/console.h> | |
666b7793 AH |
18 | #include <linux/interrupt.h> |
19 | #include <linux/platform_device.h> | |
20 | #include <linux/tty.h> | |
21 | #include <linux/tty_flip.h> | |
22 | #include <linux/slab.h> | |
23 | #include <linux/io.h> | |
24 | #include <linux/module.h> | |
e0f682e0 | 25 | #include <linux/goldfish.h> |
7157d2be MD |
26 | #include <linux/mm.h> |
27 | #include <linux/dma-mapping.h> | |
3840ed95 | 28 | #include <linux/serial_core.h> |
666b7793 | 29 | |
2296eee7 AM |
30 | /* Goldfish tty register's offsets */ |
31 | #define GOLDFISH_TTY_REG_BYTES_READY 0x04 | |
32 | #define GOLDFISH_TTY_REG_CMD 0x08 | |
33 | #define GOLDFISH_TTY_REG_DATA_PTR 0x10 | |
34 | #define GOLDFISH_TTY_REG_DATA_LEN 0x14 | |
35 | #define GOLDFISH_TTY_REG_DATA_PTR_HIGH 0x18 | |
7157d2be | 36 | #define GOLDFISH_TTY_REG_VERSION 0x20 |
2296eee7 AM |
37 | |
38 | /* Goldfish tty commands */ | |
39 | #define GOLDFISH_TTY_CMD_INT_DISABLE 0 | |
40 | #define GOLDFISH_TTY_CMD_INT_ENABLE 1 | |
41 | #define GOLDFISH_TTY_CMD_WRITE_BUFFER 2 | |
42 | #define GOLDFISH_TTY_CMD_READ_BUFFER 3 | |
666b7793 AH |
43 | |
44 | struct goldfish_tty { | |
45 | struct tty_port port; | |
46 | spinlock_t lock; | |
47 | void __iomem *base; | |
48 | u32 irq; | |
49 | int opencount; | |
50 | struct console console; | |
7157d2be MD |
51 | u32 version; |
52 | struct device *dev; | |
666b7793 AH |
53 | }; |
54 | ||
55 | static DEFINE_MUTEX(goldfish_tty_lock); | |
56 | static struct tty_driver *goldfish_tty_driver; | |
57 | static u32 goldfish_tty_line_count = 8; | |
58 | static u32 goldfish_tty_current_line_count; | |
59 | static struct goldfish_tty *goldfish_ttys; | |
60 | ||
7157d2be MD |
61 | static void do_rw_io(struct goldfish_tty *qtty, |
62 | unsigned long address, | |
63 | unsigned int count, | |
64 | int is_write) | |
666b7793 AH |
65 | { |
66 | unsigned long irq_flags; | |
666b7793 | 67 | void __iomem *base = qtty->base; |
7157d2be | 68 | |
666b7793 | 69 | spin_lock_irqsave(&qtty->lock, irq_flags); |
7157d2be | 70 | gf_write_ptr((void *)address, base + GOLDFISH_TTY_REG_DATA_PTR, |
2296eee7 AM |
71 | base + GOLDFISH_TTY_REG_DATA_PTR_HIGH); |
72 | writel(count, base + GOLDFISH_TTY_REG_DATA_LEN); | |
7157d2be MD |
73 | |
74 | if (is_write) | |
75 | writel(GOLDFISH_TTY_CMD_WRITE_BUFFER, | |
76 | base + GOLDFISH_TTY_REG_CMD); | |
77 | else | |
78 | writel(GOLDFISH_TTY_CMD_READ_BUFFER, | |
79 | base + GOLDFISH_TTY_REG_CMD); | |
80 | ||
666b7793 AH |
81 | spin_unlock_irqrestore(&qtty->lock, irq_flags); |
82 | } | |
83 | ||
7157d2be MD |
84 | static void goldfish_tty_rw(struct goldfish_tty *qtty, |
85 | unsigned long addr, | |
86 | unsigned int count, | |
87 | int is_write) | |
88 | { | |
89 | dma_addr_t dma_handle; | |
90 | enum dma_data_direction dma_dir; | |
91 | ||
92 | dma_dir = (is_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
93 | if (qtty->version > 0) { | |
94 | /* | |
95 | * Goldfish TTY for Ranchu platform uses | |
96 | * physical addresses and DMA for read/write operations | |
97 | */ | |
98 | unsigned long addr_end = addr + count; | |
99 | ||
100 | while (addr < addr_end) { | |
101 | unsigned long pg_end = (addr & PAGE_MASK) + PAGE_SIZE; | |
102 | unsigned long next = | |
103 | pg_end < addr_end ? pg_end : addr_end; | |
104 | unsigned long avail = next - addr; | |
105 | ||
106 | /* | |
107 | * Map the buffer's virtual address to the DMA address | |
108 | * so the buffer can be accessed by the device. | |
109 | */ | |
110 | dma_handle = dma_map_single(qtty->dev, (void *)addr, | |
111 | avail, dma_dir); | |
112 | ||
113 | if (dma_mapping_error(qtty->dev, dma_handle)) { | |
114 | dev_err(qtty->dev, "tty: DMA mapping error.\n"); | |
115 | return; | |
116 | } | |
117 | do_rw_io(qtty, dma_handle, avail, is_write); | |
118 | ||
119 | /* | |
120 | * Unmap the previously mapped region after | |
121 | * the completion of the read/write operation. | |
122 | */ | |
123 | dma_unmap_single(qtty->dev, dma_handle, avail, dma_dir); | |
124 | ||
125 | addr += avail; | |
126 | } | |
127 | } else { | |
128 | /* | |
129 | * Old style Goldfish TTY used on the Goldfish platform | |
130 | * uses virtual addresses. | |
131 | */ | |
132 | do_rw_io(qtty, addr, count, is_write); | |
133 | } | |
134 | } | |
135 | ||
136 | static void goldfish_tty_do_write(int line, const char *buf, | |
137 | unsigned int count) | |
138 | { | |
139 | struct goldfish_tty *qtty = &goldfish_ttys[line]; | |
140 | unsigned long address = (unsigned long)(void *)buf; | |
141 | ||
142 | goldfish_tty_rw(qtty, address, count, 1); | |
143 | } | |
144 | ||
666b7793 AH |
145 | static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id) |
146 | { | |
465893e1 | 147 | struct goldfish_tty *qtty = dev_id; |
666b7793 | 148 | void __iomem *base = qtty->base; |
7157d2be | 149 | unsigned long address; |
666b7793 AH |
150 | unsigned char *buf; |
151 | u32 count; | |
666b7793 | 152 | |
2296eee7 | 153 | count = readl(base + GOLDFISH_TTY_REG_BYTES_READY); |
d78055dc | 154 | if (count == 0) |
666b7793 AH |
155 | return IRQ_NONE; |
156 | ||
ebcf0981 | 157 | count = tty_prepare_flip_string(&qtty->port, &buf, count); |
7157d2be MD |
158 | |
159 | address = (unsigned long)(void *)buf; | |
160 | goldfish_tty_rw(qtty, address, count, 0); | |
161 | ||
ebcf0981 | 162 | tty_schedule_flip(&qtty->port); |
666b7793 AH |
163 | return IRQ_HANDLED; |
164 | } | |
165 | ||
166 | static int goldfish_tty_activate(struct tty_port *port, struct tty_struct *tty) | |
167 | { | |
d78055dc A |
168 | struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, |
169 | port); | |
2296eee7 | 170 | writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_REG_CMD); |
666b7793 AH |
171 | return 0; |
172 | } | |
173 | ||
174 | static void goldfish_tty_shutdown(struct tty_port *port) | |
175 | { | |
d78055dc A |
176 | struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, |
177 | port); | |
2296eee7 | 178 | writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_REG_CMD); |
666b7793 AH |
179 | } |
180 | ||
d78055dc | 181 | static int goldfish_tty_open(struct tty_struct *tty, struct file *filp) |
666b7793 AH |
182 | { |
183 | struct goldfish_tty *qtty = &goldfish_ttys[tty->index]; | |
184 | return tty_port_open(&qtty->port, tty, filp); | |
185 | } | |
186 | ||
d78055dc | 187 | static void goldfish_tty_close(struct tty_struct *tty, struct file *filp) |
666b7793 AH |
188 | { |
189 | tty_port_close(tty->port, tty, filp); | |
190 | } | |
191 | ||
192 | static void goldfish_tty_hangup(struct tty_struct *tty) | |
193 | { | |
194 | tty_port_hangup(tty->port); | |
195 | } | |
196 | ||
d78055dc A |
197 | static int goldfish_tty_write(struct tty_struct *tty, const unsigned char *buf, |
198 | int count) | |
666b7793 AH |
199 | { |
200 | goldfish_tty_do_write(tty->index, buf, count); | |
201 | return count; | |
202 | } | |
203 | ||
204 | static int goldfish_tty_write_room(struct tty_struct *tty) | |
205 | { | |
206 | return 0x10000; | |
207 | } | |
208 | ||
209 | static int goldfish_tty_chars_in_buffer(struct tty_struct *tty) | |
210 | { | |
211 | struct goldfish_tty *qtty = &goldfish_ttys[tty->index]; | |
212 | void __iomem *base = qtty->base; | |
2296eee7 | 213 | return readl(base + GOLDFISH_TTY_REG_BYTES_READY); |
666b7793 AH |
214 | } |
215 | ||
d78055dc A |
216 | static void goldfish_tty_console_write(struct console *co, const char *b, |
217 | unsigned count) | |
666b7793 AH |
218 | { |
219 | goldfish_tty_do_write(co->index, b, count); | |
220 | } | |
221 | ||
d78055dc A |
222 | static struct tty_driver *goldfish_tty_console_device(struct console *c, |
223 | int *index) | |
666b7793 AH |
224 | { |
225 | *index = c->index; | |
226 | return goldfish_tty_driver; | |
227 | } | |
228 | ||
229 | static int goldfish_tty_console_setup(struct console *co, char *options) | |
230 | { | |
fda2b418 | 231 | if ((unsigned)co->index >= goldfish_tty_line_count) |
666b7793 | 232 | return -ENODEV; |
a4dc9236 | 233 | if (!goldfish_ttys[co->index].base) |
666b7793 AH |
234 | return -ENODEV; |
235 | return 0; | |
236 | } | |
237 | ||
04b757df | 238 | static const struct tty_port_operations goldfish_port_ops = { |
666b7793 AH |
239 | .activate = goldfish_tty_activate, |
240 | .shutdown = goldfish_tty_shutdown | |
241 | }; | |
242 | ||
d78055dc | 243 | static const struct tty_operations goldfish_tty_ops = { |
666b7793 AH |
244 | .open = goldfish_tty_open, |
245 | .close = goldfish_tty_close, | |
246 | .hangup = goldfish_tty_hangup, | |
247 | .write = goldfish_tty_write, | |
248 | .write_room = goldfish_tty_write_room, | |
249 | .chars_in_buffer = goldfish_tty_chars_in_buffer, | |
250 | }; | |
251 | ||
252 | static int goldfish_tty_create_driver(void) | |
253 | { | |
254 | int ret; | |
255 | struct tty_driver *tty; | |
256 | ||
d78055dc A |
257 | goldfish_ttys = kzalloc(sizeof(*goldfish_ttys) * |
258 | goldfish_tty_line_count, GFP_KERNEL); | |
259 | if (goldfish_ttys == NULL) { | |
666b7793 AH |
260 | ret = -ENOMEM; |
261 | goto err_alloc_goldfish_ttys_failed; | |
262 | } | |
263 | tty = alloc_tty_driver(goldfish_tty_line_count); | |
d78055dc | 264 | if (tty == NULL) { |
666b7793 AH |
265 | ret = -ENOMEM; |
266 | goto err_alloc_tty_driver_failed; | |
267 | } | |
268 | tty->driver_name = "goldfish"; | |
269 | tty->name = "ttyGF"; | |
270 | tty->type = TTY_DRIVER_TYPE_SERIAL; | |
271 | tty->subtype = SERIAL_TYPE_NORMAL; | |
272 | tty->init_termios = tty_std_termios; | |
d78055dc A |
273 | tty->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
274 | TTY_DRIVER_DYNAMIC_DEV; | |
666b7793 AH |
275 | tty_set_operations(tty, &goldfish_tty_ops); |
276 | ret = tty_register_driver(tty); | |
d78055dc | 277 | if (ret) |
666b7793 AH |
278 | goto err_tty_register_driver_failed; |
279 | ||
280 | goldfish_tty_driver = tty; | |
281 | return 0; | |
282 | ||
283 | err_tty_register_driver_failed: | |
284 | put_tty_driver(tty); | |
285 | err_alloc_tty_driver_failed: | |
286 | kfree(goldfish_ttys); | |
287 | goldfish_ttys = NULL; | |
288 | err_alloc_goldfish_ttys_failed: | |
289 | return ret; | |
290 | } | |
291 | ||
292 | static void goldfish_tty_delete_driver(void) | |
293 | { | |
294 | tty_unregister_driver(goldfish_tty_driver); | |
295 | put_tty_driver(goldfish_tty_driver); | |
296 | goldfish_tty_driver = NULL; | |
297 | kfree(goldfish_ttys); | |
298 | goldfish_ttys = NULL; | |
299 | } | |
300 | ||
301 | static int goldfish_tty_probe(struct platform_device *pdev) | |
302 | { | |
303 | struct goldfish_tty *qtty; | |
7157d2be | 304 | int ret = -ENODEV; |
666b7793 AH |
305 | struct resource *r; |
306 | struct device *ttydev; | |
307 | void __iomem *base; | |
308 | u32 irq; | |
465893e1 | 309 | unsigned int line; |
666b7793 AH |
310 | |
311 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
7157d2be MD |
312 | if (!r) { |
313 | pr_err("goldfish_tty: No MEM resource available!\n"); | |
314 | return -ENOMEM; | |
315 | } | |
666b7793 AH |
316 | |
317 | base = ioremap(r->start, 0x1000); | |
7157d2be MD |
318 | if (!base) { |
319 | pr_err("goldfish_tty: Unable to ioremap base!\n"); | |
320 | return -ENOMEM; | |
321 | } | |
666b7793 AH |
322 | |
323 | r = platform_get_resource(pdev, IORESOURCE_IRQ, 0); | |
7157d2be MD |
324 | if (!r) { |
325 | pr_err("goldfish_tty: No IRQ resource available!\n"); | |
666b7793 | 326 | goto err_unmap; |
7157d2be | 327 | } |
666b7793 AH |
328 | |
329 | irq = r->start; | |
330 | ||
666b7793 | 331 | mutex_lock(&goldfish_tty_lock); |
465893e1 GH |
332 | |
333 | if (pdev->id == PLATFORM_DEVID_NONE) | |
334 | line = goldfish_tty_current_line_count; | |
335 | else | |
336 | line = pdev->id; | |
337 | ||
7157d2be MD |
338 | if (line >= goldfish_tty_line_count) { |
339 | pr_err("goldfish_tty: Reached maximum tty number of %d.\n", | |
340 | goldfish_tty_current_line_count); | |
341 | ret = -ENOMEM; | |
342 | goto err_unlock; | |
343 | } | |
465893e1 | 344 | |
d78055dc | 345 | if (goldfish_tty_current_line_count == 0) { |
666b7793 | 346 | ret = goldfish_tty_create_driver(); |
d78055dc | 347 | if (ret) |
7157d2be | 348 | goto err_unlock; |
666b7793 AH |
349 | } |
350 | goldfish_tty_current_line_count++; | |
351 | ||
465893e1 | 352 | qtty = &goldfish_ttys[line]; |
666b7793 AH |
353 | spin_lock_init(&qtty->lock); |
354 | tty_port_init(&qtty->port); | |
355 | qtty->port.ops = &goldfish_port_ops; | |
356 | qtty->base = base; | |
357 | qtty->irq = irq; | |
7157d2be MD |
358 | qtty->dev = &pdev->dev; |
359 | ||
360 | /* | |
361 | * Goldfish TTY device used by the Goldfish emulator | |
362 | * should identify itself with 0, forcing the driver | |
363 | * to use virtual addresses. Goldfish TTY device | |
364 | * on Ranchu emulator (qemu2) returns 1 here and | |
365 | * driver will use physical addresses. | |
366 | */ | |
367 | qtty->version = readl(base + GOLDFISH_TTY_REG_VERSION); | |
368 | ||
369 | /* | |
370 | * Goldfish TTY device on Ranchu emulator (qemu2) | |
371 | * will use DMA for read/write IO operations. | |
372 | */ | |
373 | if (qtty->version > 0) { | |
374 | /* | |
375 | * Initialize dma_mask to 32-bits. | |
376 | */ | |
377 | if (!pdev->dev.dma_mask) | |
378 | pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask; | |
379 | ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32)); | |
380 | if (ret) { | |
381 | dev_err(&pdev->dev, "No suitable DMA available.\n"); | |
382 | goto err_dec_line_count; | |
383 | } | |
384 | } | |
666b7793 | 385 | |
2296eee7 | 386 | writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_REG_CMD); |
666b7793 | 387 | |
d78055dc | 388 | ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED, |
7157d2be MD |
389 | "goldfish_tty", qtty); |
390 | if (ret) { | |
391 | pr_err("goldfish_tty: No IRQ available!\n"); | |
392 | goto err_dec_line_count; | |
393 | } | |
666b7793 AH |
394 | |
395 | ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver, | |
7157d2be | 396 | line, &pdev->dev); |
d78055dc | 397 | if (IS_ERR(ttydev)) { |
666b7793 AH |
398 | ret = PTR_ERR(ttydev); |
399 | goto err_tty_register_device_failed; | |
400 | } | |
401 | ||
402 | strcpy(qtty->console.name, "ttyGF"); | |
403 | qtty->console.write = goldfish_tty_console_write; | |
404 | qtty->console.device = goldfish_tty_console_device; | |
405 | qtty->console.setup = goldfish_tty_console_setup; | |
406 | qtty->console.flags = CON_PRINTBUFFER; | |
465893e1 | 407 | qtty->console.index = line; |
666b7793 | 408 | register_console(&qtty->console); |
465893e1 | 409 | platform_set_drvdata(pdev, qtty); |
666b7793 AH |
410 | |
411 | mutex_unlock(&goldfish_tty_lock); | |
412 | return 0; | |
413 | ||
666b7793 | 414 | err_tty_register_device_failed: |
1a5c2d1d | 415 | free_irq(irq, qtty); |
7157d2be | 416 | err_dec_line_count: |
666b7793 | 417 | goldfish_tty_current_line_count--; |
d78055dc | 418 | if (goldfish_tty_current_line_count == 0) |
666b7793 | 419 | goldfish_tty_delete_driver(); |
7157d2be | 420 | err_unlock: |
666b7793 AH |
421 | mutex_unlock(&goldfish_tty_lock); |
422 | err_unmap: | |
423 | iounmap(base); | |
424 | return ret; | |
425 | } | |
426 | ||
427 | static int goldfish_tty_remove(struct platform_device *pdev) | |
428 | { | |
465893e1 | 429 | struct goldfish_tty *qtty = platform_get_drvdata(pdev); |
666b7793 AH |
430 | |
431 | mutex_lock(&goldfish_tty_lock); | |
432 | ||
666b7793 | 433 | unregister_console(&qtty->console); |
465893e1 | 434 | tty_unregister_device(goldfish_tty_driver, qtty->console.index); |
666b7793 | 435 | iounmap(qtty->base); |
a4dc9236 | 436 | qtty->base = NULL; |
666b7793 AH |
437 | free_irq(qtty->irq, pdev); |
438 | goldfish_tty_current_line_count--; | |
d78055dc | 439 | if (goldfish_tty_current_line_count == 0) |
666b7793 AH |
440 | goldfish_tty_delete_driver(); |
441 | mutex_unlock(&goldfish_tty_lock); | |
442 | return 0; | |
443 | } | |
444 | ||
3840ed95 MD |
445 | static void gf_early_console_putchar(struct uart_port *port, int ch) |
446 | { | |
447 | __raw_writel(ch, port->membase); | |
448 | } | |
449 | ||
450 | static void gf_early_write(struct console *con, const char *s, unsigned int n) | |
451 | { | |
452 | struct earlycon_device *dev = con->data; | |
453 | ||
454 | uart_console_write(&dev->port, s, n, gf_early_console_putchar); | |
455 | } | |
456 | ||
457 | static int __init gf_earlycon_setup(struct earlycon_device *device, | |
458 | const char *opt) | |
459 | { | |
460 | if (!device->port.membase) | |
461 | return -ENODEV; | |
462 | ||
463 | device->con->write = gf_early_write; | |
464 | return 0; | |
465 | } | |
466 | ||
467 | OF_EARLYCON_DECLARE(early_gf_tty, "google,goldfish-tty", gf_earlycon_setup); | |
468 | ||
9b883eea MD |
469 | static const struct of_device_id goldfish_tty_of_match[] = { |
470 | { .compatible = "google,goldfish-tty", }, | |
471 | {}, | |
472 | }; | |
473 | ||
474 | MODULE_DEVICE_TABLE(of, goldfish_tty_of_match); | |
475 | ||
666b7793 AH |
476 | static struct platform_driver goldfish_tty_platform_driver = { |
477 | .probe = goldfish_tty_probe, | |
478 | .remove = goldfish_tty_remove, | |
479 | .driver = { | |
9b883eea MD |
480 | .name = "goldfish_tty", |
481 | .of_match_table = goldfish_tty_of_match, | |
666b7793 AH |
482 | } |
483 | }; | |
484 | ||
485 | module_platform_driver(goldfish_tty_platform_driver); | |
486 | ||
487 | MODULE_LICENSE("GPL v2"); |