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Commit | Line | Data |
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e3b3d0f5 | 1 | // SPDX-License-Identifier: GPL-2.0 |
666b7793 AH |
2 | /* |
3 | * Copyright (C) 2007 Google, Inc. | |
4 | * Copyright (C) 2012 Intel, Inc. | |
3840ed95 | 5 | * Copyright (C) 2017 Imagination Technologies Ltd. |
666b7793 AH |
6 | */ |
7 | ||
8 | #include <linux/console.h> | |
666b7793 AH |
9 | #include <linux/interrupt.h> |
10 | #include <linux/platform_device.h> | |
11 | #include <linux/tty.h> | |
12 | #include <linux/tty_flip.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/io.h> | |
15 | #include <linux/module.h> | |
e0f682e0 | 16 | #include <linux/goldfish.h> |
7157d2be MD |
17 | #include <linux/mm.h> |
18 | #include <linux/dma-mapping.h> | |
3840ed95 | 19 | #include <linux/serial_core.h> |
666b7793 | 20 | |
2296eee7 AM |
21 | /* Goldfish tty register's offsets */ |
22 | #define GOLDFISH_TTY_REG_BYTES_READY 0x04 | |
23 | #define GOLDFISH_TTY_REG_CMD 0x08 | |
24 | #define GOLDFISH_TTY_REG_DATA_PTR 0x10 | |
25 | #define GOLDFISH_TTY_REG_DATA_LEN 0x14 | |
26 | #define GOLDFISH_TTY_REG_DATA_PTR_HIGH 0x18 | |
7157d2be | 27 | #define GOLDFISH_TTY_REG_VERSION 0x20 |
2296eee7 AM |
28 | |
29 | /* Goldfish tty commands */ | |
30 | #define GOLDFISH_TTY_CMD_INT_DISABLE 0 | |
31 | #define GOLDFISH_TTY_CMD_INT_ENABLE 1 | |
32 | #define GOLDFISH_TTY_CMD_WRITE_BUFFER 2 | |
33 | #define GOLDFISH_TTY_CMD_READ_BUFFER 3 | |
666b7793 AH |
34 | |
35 | struct goldfish_tty { | |
36 | struct tty_port port; | |
37 | spinlock_t lock; | |
38 | void __iomem *base; | |
39 | u32 irq; | |
40 | int opencount; | |
41 | struct console console; | |
7157d2be MD |
42 | u32 version; |
43 | struct device *dev; | |
666b7793 AH |
44 | }; |
45 | ||
46 | static DEFINE_MUTEX(goldfish_tty_lock); | |
47 | static struct tty_driver *goldfish_tty_driver; | |
48 | static u32 goldfish_tty_line_count = 8; | |
49 | static u32 goldfish_tty_current_line_count; | |
50 | static struct goldfish_tty *goldfish_ttys; | |
51 | ||
7157d2be MD |
52 | static void do_rw_io(struct goldfish_tty *qtty, |
53 | unsigned long address, | |
54 | unsigned int count, | |
55 | int is_write) | |
666b7793 AH |
56 | { |
57 | unsigned long irq_flags; | |
666b7793 | 58 | void __iomem *base = qtty->base; |
7157d2be | 59 | |
666b7793 | 60 | spin_lock_irqsave(&qtty->lock, irq_flags); |
7157d2be | 61 | gf_write_ptr((void *)address, base + GOLDFISH_TTY_REG_DATA_PTR, |
2296eee7 AM |
62 | base + GOLDFISH_TTY_REG_DATA_PTR_HIGH); |
63 | writel(count, base + GOLDFISH_TTY_REG_DATA_LEN); | |
7157d2be MD |
64 | |
65 | if (is_write) | |
66 | writel(GOLDFISH_TTY_CMD_WRITE_BUFFER, | |
67 | base + GOLDFISH_TTY_REG_CMD); | |
68 | else | |
69 | writel(GOLDFISH_TTY_CMD_READ_BUFFER, | |
70 | base + GOLDFISH_TTY_REG_CMD); | |
71 | ||
666b7793 AH |
72 | spin_unlock_irqrestore(&qtty->lock, irq_flags); |
73 | } | |
74 | ||
7157d2be MD |
75 | static void goldfish_tty_rw(struct goldfish_tty *qtty, |
76 | unsigned long addr, | |
77 | unsigned int count, | |
78 | int is_write) | |
79 | { | |
80 | dma_addr_t dma_handle; | |
81 | enum dma_data_direction dma_dir; | |
82 | ||
83 | dma_dir = (is_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
84 | if (qtty->version > 0) { | |
85 | /* | |
86 | * Goldfish TTY for Ranchu platform uses | |
87 | * physical addresses and DMA for read/write operations | |
88 | */ | |
89 | unsigned long addr_end = addr + count; | |
90 | ||
91 | while (addr < addr_end) { | |
92 | unsigned long pg_end = (addr & PAGE_MASK) + PAGE_SIZE; | |
93 | unsigned long next = | |
94 | pg_end < addr_end ? pg_end : addr_end; | |
95 | unsigned long avail = next - addr; | |
96 | ||
97 | /* | |
98 | * Map the buffer's virtual address to the DMA address | |
99 | * so the buffer can be accessed by the device. | |
100 | */ | |
101 | dma_handle = dma_map_single(qtty->dev, (void *)addr, | |
102 | avail, dma_dir); | |
103 | ||
104 | if (dma_mapping_error(qtty->dev, dma_handle)) { | |
105 | dev_err(qtty->dev, "tty: DMA mapping error.\n"); | |
106 | return; | |
107 | } | |
108 | do_rw_io(qtty, dma_handle, avail, is_write); | |
109 | ||
110 | /* | |
111 | * Unmap the previously mapped region after | |
112 | * the completion of the read/write operation. | |
113 | */ | |
114 | dma_unmap_single(qtty->dev, dma_handle, avail, dma_dir); | |
115 | ||
116 | addr += avail; | |
117 | } | |
118 | } else { | |
119 | /* | |
120 | * Old style Goldfish TTY used on the Goldfish platform | |
121 | * uses virtual addresses. | |
122 | */ | |
123 | do_rw_io(qtty, addr, count, is_write); | |
124 | } | |
125 | } | |
126 | ||
127 | static void goldfish_tty_do_write(int line, const char *buf, | |
128 | unsigned int count) | |
129 | { | |
130 | struct goldfish_tty *qtty = &goldfish_ttys[line]; | |
131 | unsigned long address = (unsigned long)(void *)buf; | |
132 | ||
133 | goldfish_tty_rw(qtty, address, count, 1); | |
134 | } | |
135 | ||
666b7793 AH |
136 | static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id) |
137 | { | |
465893e1 | 138 | struct goldfish_tty *qtty = dev_id; |
666b7793 | 139 | void __iomem *base = qtty->base; |
7157d2be | 140 | unsigned long address; |
666b7793 AH |
141 | unsigned char *buf; |
142 | u32 count; | |
666b7793 | 143 | |
2296eee7 | 144 | count = readl(base + GOLDFISH_TTY_REG_BYTES_READY); |
d78055dc | 145 | if (count == 0) |
666b7793 AH |
146 | return IRQ_NONE; |
147 | ||
ebcf0981 | 148 | count = tty_prepare_flip_string(&qtty->port, &buf, count); |
7157d2be MD |
149 | |
150 | address = (unsigned long)(void *)buf; | |
151 | goldfish_tty_rw(qtty, address, count, 0); | |
152 | ||
ebcf0981 | 153 | tty_schedule_flip(&qtty->port); |
666b7793 AH |
154 | return IRQ_HANDLED; |
155 | } | |
156 | ||
157 | static int goldfish_tty_activate(struct tty_port *port, struct tty_struct *tty) | |
158 | { | |
d78055dc A |
159 | struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, |
160 | port); | |
2296eee7 | 161 | writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_REG_CMD); |
666b7793 AH |
162 | return 0; |
163 | } | |
164 | ||
165 | static void goldfish_tty_shutdown(struct tty_port *port) | |
166 | { | |
d78055dc A |
167 | struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, |
168 | port); | |
2296eee7 | 169 | writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_REG_CMD); |
666b7793 AH |
170 | } |
171 | ||
d78055dc | 172 | static int goldfish_tty_open(struct tty_struct *tty, struct file *filp) |
666b7793 AH |
173 | { |
174 | struct goldfish_tty *qtty = &goldfish_ttys[tty->index]; | |
175 | return tty_port_open(&qtty->port, tty, filp); | |
176 | } | |
177 | ||
d78055dc | 178 | static void goldfish_tty_close(struct tty_struct *tty, struct file *filp) |
666b7793 AH |
179 | { |
180 | tty_port_close(tty->port, tty, filp); | |
181 | } | |
182 | ||
183 | static void goldfish_tty_hangup(struct tty_struct *tty) | |
184 | { | |
185 | tty_port_hangup(tty->port); | |
186 | } | |
187 | ||
d78055dc A |
188 | static int goldfish_tty_write(struct tty_struct *tty, const unsigned char *buf, |
189 | int count) | |
666b7793 AH |
190 | { |
191 | goldfish_tty_do_write(tty->index, buf, count); | |
192 | return count; | |
193 | } | |
194 | ||
195 | static int goldfish_tty_write_room(struct tty_struct *tty) | |
196 | { | |
197 | return 0x10000; | |
198 | } | |
199 | ||
200 | static int goldfish_tty_chars_in_buffer(struct tty_struct *tty) | |
201 | { | |
202 | struct goldfish_tty *qtty = &goldfish_ttys[tty->index]; | |
203 | void __iomem *base = qtty->base; | |
2296eee7 | 204 | return readl(base + GOLDFISH_TTY_REG_BYTES_READY); |
666b7793 AH |
205 | } |
206 | ||
d78055dc A |
207 | static void goldfish_tty_console_write(struct console *co, const char *b, |
208 | unsigned count) | |
666b7793 AH |
209 | { |
210 | goldfish_tty_do_write(co->index, b, count); | |
211 | } | |
212 | ||
d78055dc A |
213 | static struct tty_driver *goldfish_tty_console_device(struct console *c, |
214 | int *index) | |
666b7793 AH |
215 | { |
216 | *index = c->index; | |
217 | return goldfish_tty_driver; | |
218 | } | |
219 | ||
220 | static int goldfish_tty_console_setup(struct console *co, char *options) | |
221 | { | |
fda2b418 | 222 | if ((unsigned)co->index >= goldfish_tty_line_count) |
666b7793 | 223 | return -ENODEV; |
a4dc9236 | 224 | if (!goldfish_ttys[co->index].base) |
666b7793 AH |
225 | return -ENODEV; |
226 | return 0; | |
227 | } | |
228 | ||
04b757df | 229 | static const struct tty_port_operations goldfish_port_ops = { |
666b7793 AH |
230 | .activate = goldfish_tty_activate, |
231 | .shutdown = goldfish_tty_shutdown | |
232 | }; | |
233 | ||
d78055dc | 234 | static const struct tty_operations goldfish_tty_ops = { |
666b7793 AH |
235 | .open = goldfish_tty_open, |
236 | .close = goldfish_tty_close, | |
237 | .hangup = goldfish_tty_hangup, | |
238 | .write = goldfish_tty_write, | |
239 | .write_room = goldfish_tty_write_room, | |
240 | .chars_in_buffer = goldfish_tty_chars_in_buffer, | |
241 | }; | |
242 | ||
243 | static int goldfish_tty_create_driver(void) | |
244 | { | |
245 | int ret; | |
246 | struct tty_driver *tty; | |
247 | ||
d78055dc A |
248 | goldfish_ttys = kzalloc(sizeof(*goldfish_ttys) * |
249 | goldfish_tty_line_count, GFP_KERNEL); | |
250 | if (goldfish_ttys == NULL) { | |
666b7793 AH |
251 | ret = -ENOMEM; |
252 | goto err_alloc_goldfish_ttys_failed; | |
253 | } | |
254 | tty = alloc_tty_driver(goldfish_tty_line_count); | |
d78055dc | 255 | if (tty == NULL) { |
666b7793 AH |
256 | ret = -ENOMEM; |
257 | goto err_alloc_tty_driver_failed; | |
258 | } | |
259 | tty->driver_name = "goldfish"; | |
260 | tty->name = "ttyGF"; | |
261 | tty->type = TTY_DRIVER_TYPE_SERIAL; | |
262 | tty->subtype = SERIAL_TYPE_NORMAL; | |
263 | tty->init_termios = tty_std_termios; | |
d78055dc A |
264 | tty->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
265 | TTY_DRIVER_DYNAMIC_DEV; | |
666b7793 AH |
266 | tty_set_operations(tty, &goldfish_tty_ops); |
267 | ret = tty_register_driver(tty); | |
d78055dc | 268 | if (ret) |
666b7793 AH |
269 | goto err_tty_register_driver_failed; |
270 | ||
271 | goldfish_tty_driver = tty; | |
272 | return 0; | |
273 | ||
274 | err_tty_register_driver_failed: | |
275 | put_tty_driver(tty); | |
276 | err_alloc_tty_driver_failed: | |
277 | kfree(goldfish_ttys); | |
278 | goldfish_ttys = NULL; | |
279 | err_alloc_goldfish_ttys_failed: | |
280 | return ret; | |
281 | } | |
282 | ||
283 | static void goldfish_tty_delete_driver(void) | |
284 | { | |
285 | tty_unregister_driver(goldfish_tty_driver); | |
286 | put_tty_driver(goldfish_tty_driver); | |
287 | goldfish_tty_driver = NULL; | |
288 | kfree(goldfish_ttys); | |
289 | goldfish_ttys = NULL; | |
290 | } | |
291 | ||
292 | static int goldfish_tty_probe(struct platform_device *pdev) | |
293 | { | |
294 | struct goldfish_tty *qtty; | |
7157d2be | 295 | int ret = -ENODEV; |
666b7793 AH |
296 | struct resource *r; |
297 | struct device *ttydev; | |
298 | void __iomem *base; | |
299 | u32 irq; | |
465893e1 | 300 | unsigned int line; |
666b7793 AH |
301 | |
302 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
7157d2be MD |
303 | if (!r) { |
304 | pr_err("goldfish_tty: No MEM resource available!\n"); | |
305 | return -ENOMEM; | |
306 | } | |
666b7793 AH |
307 | |
308 | base = ioremap(r->start, 0x1000); | |
7157d2be MD |
309 | if (!base) { |
310 | pr_err("goldfish_tty: Unable to ioremap base!\n"); | |
311 | return -ENOMEM; | |
312 | } | |
666b7793 AH |
313 | |
314 | r = platform_get_resource(pdev, IORESOURCE_IRQ, 0); | |
7157d2be MD |
315 | if (!r) { |
316 | pr_err("goldfish_tty: No IRQ resource available!\n"); | |
666b7793 | 317 | goto err_unmap; |
7157d2be | 318 | } |
666b7793 AH |
319 | |
320 | irq = r->start; | |
321 | ||
666b7793 | 322 | mutex_lock(&goldfish_tty_lock); |
465893e1 GH |
323 | |
324 | if (pdev->id == PLATFORM_DEVID_NONE) | |
325 | line = goldfish_tty_current_line_count; | |
326 | else | |
327 | line = pdev->id; | |
328 | ||
7157d2be MD |
329 | if (line >= goldfish_tty_line_count) { |
330 | pr_err("goldfish_tty: Reached maximum tty number of %d.\n", | |
331 | goldfish_tty_current_line_count); | |
332 | ret = -ENOMEM; | |
333 | goto err_unlock; | |
334 | } | |
465893e1 | 335 | |
d78055dc | 336 | if (goldfish_tty_current_line_count == 0) { |
666b7793 | 337 | ret = goldfish_tty_create_driver(); |
d78055dc | 338 | if (ret) |
7157d2be | 339 | goto err_unlock; |
666b7793 AH |
340 | } |
341 | goldfish_tty_current_line_count++; | |
342 | ||
465893e1 | 343 | qtty = &goldfish_ttys[line]; |
666b7793 AH |
344 | spin_lock_init(&qtty->lock); |
345 | tty_port_init(&qtty->port); | |
346 | qtty->port.ops = &goldfish_port_ops; | |
347 | qtty->base = base; | |
348 | qtty->irq = irq; | |
7157d2be MD |
349 | qtty->dev = &pdev->dev; |
350 | ||
351 | /* | |
352 | * Goldfish TTY device used by the Goldfish emulator | |
353 | * should identify itself with 0, forcing the driver | |
354 | * to use virtual addresses. Goldfish TTY device | |
355 | * on Ranchu emulator (qemu2) returns 1 here and | |
356 | * driver will use physical addresses. | |
357 | */ | |
358 | qtty->version = readl(base + GOLDFISH_TTY_REG_VERSION); | |
359 | ||
360 | /* | |
361 | * Goldfish TTY device on Ranchu emulator (qemu2) | |
362 | * will use DMA for read/write IO operations. | |
363 | */ | |
364 | if (qtty->version > 0) { | |
365 | /* | |
366 | * Initialize dma_mask to 32-bits. | |
367 | */ | |
368 | if (!pdev->dev.dma_mask) | |
369 | pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask; | |
370 | ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32)); | |
371 | if (ret) { | |
372 | dev_err(&pdev->dev, "No suitable DMA available.\n"); | |
373 | goto err_dec_line_count; | |
374 | } | |
375 | } | |
666b7793 | 376 | |
2296eee7 | 377 | writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_REG_CMD); |
666b7793 | 378 | |
d78055dc | 379 | ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED, |
7157d2be MD |
380 | "goldfish_tty", qtty); |
381 | if (ret) { | |
382 | pr_err("goldfish_tty: No IRQ available!\n"); | |
383 | goto err_dec_line_count; | |
384 | } | |
666b7793 AH |
385 | |
386 | ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver, | |
7157d2be | 387 | line, &pdev->dev); |
d78055dc | 388 | if (IS_ERR(ttydev)) { |
666b7793 AH |
389 | ret = PTR_ERR(ttydev); |
390 | goto err_tty_register_device_failed; | |
391 | } | |
392 | ||
393 | strcpy(qtty->console.name, "ttyGF"); | |
394 | qtty->console.write = goldfish_tty_console_write; | |
395 | qtty->console.device = goldfish_tty_console_device; | |
396 | qtty->console.setup = goldfish_tty_console_setup; | |
397 | qtty->console.flags = CON_PRINTBUFFER; | |
465893e1 | 398 | qtty->console.index = line; |
666b7793 | 399 | register_console(&qtty->console); |
465893e1 | 400 | platform_set_drvdata(pdev, qtty); |
666b7793 AH |
401 | |
402 | mutex_unlock(&goldfish_tty_lock); | |
403 | return 0; | |
404 | ||
666b7793 | 405 | err_tty_register_device_failed: |
1a5c2d1d | 406 | free_irq(irq, qtty); |
7157d2be | 407 | err_dec_line_count: |
666b7793 | 408 | goldfish_tty_current_line_count--; |
d78055dc | 409 | if (goldfish_tty_current_line_count == 0) |
666b7793 | 410 | goldfish_tty_delete_driver(); |
7157d2be | 411 | err_unlock: |
666b7793 AH |
412 | mutex_unlock(&goldfish_tty_lock); |
413 | err_unmap: | |
414 | iounmap(base); | |
415 | return ret; | |
416 | } | |
417 | ||
418 | static int goldfish_tty_remove(struct platform_device *pdev) | |
419 | { | |
465893e1 | 420 | struct goldfish_tty *qtty = platform_get_drvdata(pdev); |
666b7793 AH |
421 | |
422 | mutex_lock(&goldfish_tty_lock); | |
423 | ||
666b7793 | 424 | unregister_console(&qtty->console); |
465893e1 | 425 | tty_unregister_device(goldfish_tty_driver, qtty->console.index); |
666b7793 | 426 | iounmap(qtty->base); |
a4dc9236 | 427 | qtty->base = NULL; |
666b7793 AH |
428 | free_irq(qtty->irq, pdev); |
429 | goldfish_tty_current_line_count--; | |
d78055dc | 430 | if (goldfish_tty_current_line_count == 0) |
666b7793 AH |
431 | goldfish_tty_delete_driver(); |
432 | mutex_unlock(&goldfish_tty_lock); | |
433 | return 0; | |
434 | } | |
435 | ||
3840ed95 MD |
436 | static void gf_early_console_putchar(struct uart_port *port, int ch) |
437 | { | |
438 | __raw_writel(ch, port->membase); | |
439 | } | |
440 | ||
441 | static void gf_early_write(struct console *con, const char *s, unsigned int n) | |
442 | { | |
443 | struct earlycon_device *dev = con->data; | |
444 | ||
445 | uart_console_write(&dev->port, s, n, gf_early_console_putchar); | |
446 | } | |
447 | ||
448 | static int __init gf_earlycon_setup(struct earlycon_device *device, | |
449 | const char *opt) | |
450 | { | |
451 | if (!device->port.membase) | |
452 | return -ENODEV; | |
453 | ||
454 | device->con->write = gf_early_write; | |
455 | return 0; | |
456 | } | |
457 | ||
458 | OF_EARLYCON_DECLARE(early_gf_tty, "google,goldfish-tty", gf_earlycon_setup); | |
459 | ||
9b883eea MD |
460 | static const struct of_device_id goldfish_tty_of_match[] = { |
461 | { .compatible = "google,goldfish-tty", }, | |
462 | {}, | |
463 | }; | |
464 | ||
465 | MODULE_DEVICE_TABLE(of, goldfish_tty_of_match); | |
466 | ||
666b7793 AH |
467 | static struct platform_driver goldfish_tty_platform_driver = { |
468 | .probe = goldfish_tty_probe, | |
469 | .remove = goldfish_tty_remove, | |
470 | .driver = { | |
9b883eea MD |
471 | .name = "goldfish_tty", |
472 | .of_match_table = goldfish_tty_of_match, | |
666b7793 AH |
473 | } |
474 | }; | |
475 | ||
476 | module_platform_driver(goldfish_tty_platform_driver); | |
477 | ||
478 | MODULE_LICENSE("GPL v2"); |