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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> | |
ac316725 | 16 | #include <linux/mod_devicetable.h> |
e0f682e0 | 17 | #include <linux/goldfish.h> |
7157d2be MD |
18 | #include <linux/mm.h> |
19 | #include <linux/dma-mapping.h> | |
3840ed95 | 20 | #include <linux/serial_core.h> |
666b7793 | 21 | |
2296eee7 AM |
22 | /* Goldfish tty register's offsets */ |
23 | #define GOLDFISH_TTY_REG_BYTES_READY 0x04 | |
24 | #define GOLDFISH_TTY_REG_CMD 0x08 | |
25 | #define GOLDFISH_TTY_REG_DATA_PTR 0x10 | |
26 | #define GOLDFISH_TTY_REG_DATA_LEN 0x14 | |
27 | #define GOLDFISH_TTY_REG_DATA_PTR_HIGH 0x18 | |
7157d2be | 28 | #define GOLDFISH_TTY_REG_VERSION 0x20 |
2296eee7 AM |
29 | |
30 | /* Goldfish tty commands */ | |
31 | #define GOLDFISH_TTY_CMD_INT_DISABLE 0 | |
32 | #define GOLDFISH_TTY_CMD_INT_ENABLE 1 | |
33 | #define GOLDFISH_TTY_CMD_WRITE_BUFFER 2 | |
34 | #define GOLDFISH_TTY_CMD_READ_BUFFER 3 | |
666b7793 AH |
35 | |
36 | struct goldfish_tty { | |
37 | struct tty_port port; | |
38 | spinlock_t lock; | |
39 | void __iomem *base; | |
40 | u32 irq; | |
41 | int opencount; | |
42 | struct console console; | |
7157d2be MD |
43 | u32 version; |
44 | struct device *dev; | |
666b7793 AH |
45 | }; |
46 | ||
47 | static DEFINE_MUTEX(goldfish_tty_lock); | |
48 | static struct tty_driver *goldfish_tty_driver; | |
49 | static u32 goldfish_tty_line_count = 8; | |
50 | static u32 goldfish_tty_current_line_count; | |
51 | static struct goldfish_tty *goldfish_ttys; | |
52 | ||
7157d2be MD |
53 | static void do_rw_io(struct goldfish_tty *qtty, |
54 | unsigned long address, | |
55 | unsigned int count, | |
56 | int is_write) | |
666b7793 AH |
57 | { |
58 | unsigned long irq_flags; | |
666b7793 | 59 | void __iomem *base = qtty->base; |
7157d2be | 60 | |
666b7793 | 61 | spin_lock_irqsave(&qtty->lock, irq_flags); |
7157d2be | 62 | gf_write_ptr((void *)address, base + GOLDFISH_TTY_REG_DATA_PTR, |
2296eee7 | 63 | base + GOLDFISH_TTY_REG_DATA_PTR_HIGH); |
da31de35 | 64 | __raw_writel(count, base + GOLDFISH_TTY_REG_DATA_LEN); |
7157d2be MD |
65 | |
66 | if (is_write) | |
da31de35 | 67 | __raw_writel(GOLDFISH_TTY_CMD_WRITE_BUFFER, |
7157d2be MD |
68 | base + GOLDFISH_TTY_REG_CMD); |
69 | else | |
da31de35 | 70 | __raw_writel(GOLDFISH_TTY_CMD_READ_BUFFER, |
7157d2be MD |
71 | base + GOLDFISH_TTY_REG_CMD); |
72 | ||
666b7793 AH |
73 | spin_unlock_irqrestore(&qtty->lock, irq_flags); |
74 | } | |
75 | ||
7157d2be MD |
76 | static void goldfish_tty_rw(struct goldfish_tty *qtty, |
77 | unsigned long addr, | |
78 | unsigned int count, | |
79 | int is_write) | |
80 | { | |
81 | dma_addr_t dma_handle; | |
82 | enum dma_data_direction dma_dir; | |
83 | ||
84 | dma_dir = (is_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
85 | if (qtty->version > 0) { | |
86 | /* | |
87 | * Goldfish TTY for Ranchu platform uses | |
88 | * physical addresses and DMA for read/write operations | |
89 | */ | |
90 | unsigned long addr_end = addr + count; | |
91 | ||
92 | while (addr < addr_end) { | |
93 | unsigned long pg_end = (addr & PAGE_MASK) + PAGE_SIZE; | |
94 | unsigned long next = | |
95 | pg_end < addr_end ? pg_end : addr_end; | |
96 | unsigned long avail = next - addr; | |
97 | ||
98 | /* | |
99 | * Map the buffer's virtual address to the DMA address | |
100 | * so the buffer can be accessed by the device. | |
101 | */ | |
102 | dma_handle = dma_map_single(qtty->dev, (void *)addr, | |
103 | avail, dma_dir); | |
104 | ||
105 | if (dma_mapping_error(qtty->dev, dma_handle)) { | |
106 | dev_err(qtty->dev, "tty: DMA mapping error.\n"); | |
107 | return; | |
108 | } | |
109 | do_rw_io(qtty, dma_handle, avail, is_write); | |
110 | ||
111 | /* | |
112 | * Unmap the previously mapped region after | |
113 | * the completion of the read/write operation. | |
114 | */ | |
115 | dma_unmap_single(qtty->dev, dma_handle, avail, dma_dir); | |
116 | ||
117 | addr += avail; | |
118 | } | |
119 | } else { | |
120 | /* | |
121 | * Old style Goldfish TTY used on the Goldfish platform | |
122 | * uses virtual addresses. | |
123 | */ | |
124 | do_rw_io(qtty, addr, count, is_write); | |
125 | } | |
126 | } | |
127 | ||
128 | static void goldfish_tty_do_write(int line, const char *buf, | |
129 | unsigned int count) | |
130 | { | |
131 | struct goldfish_tty *qtty = &goldfish_ttys[line]; | |
132 | unsigned long address = (unsigned long)(void *)buf; | |
133 | ||
134 | goldfish_tty_rw(qtty, address, count, 1); | |
135 | } | |
136 | ||
666b7793 AH |
137 | static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id) |
138 | { | |
465893e1 | 139 | struct goldfish_tty *qtty = dev_id; |
666b7793 | 140 | void __iomem *base = qtty->base; |
7157d2be | 141 | unsigned long address; |
666b7793 AH |
142 | unsigned char *buf; |
143 | u32 count; | |
666b7793 | 144 | |
da31de35 | 145 | count = __raw_readl(base + GOLDFISH_TTY_REG_BYTES_READY); |
d78055dc | 146 | if (count == 0) |
666b7793 AH |
147 | return IRQ_NONE; |
148 | ||
ebcf0981 | 149 | count = tty_prepare_flip_string(&qtty->port, &buf, count); |
7157d2be MD |
150 | |
151 | address = (unsigned long)(void *)buf; | |
152 | goldfish_tty_rw(qtty, address, count, 0); | |
153 | ||
ebcf0981 | 154 | tty_schedule_flip(&qtty->port); |
666b7793 AH |
155 | return IRQ_HANDLED; |
156 | } | |
157 | ||
158 | static int goldfish_tty_activate(struct tty_port *port, struct tty_struct *tty) | |
159 | { | |
d78055dc A |
160 | struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, |
161 | port); | |
da31de35 | 162 | __raw_writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_REG_CMD); |
666b7793 AH |
163 | return 0; |
164 | } | |
165 | ||
166 | static void goldfish_tty_shutdown(struct tty_port *port) | |
167 | { | |
d78055dc A |
168 | struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, |
169 | port); | |
da31de35 | 170 | __raw_writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_REG_CMD); |
666b7793 AH |
171 | } |
172 | ||
d78055dc | 173 | static int goldfish_tty_open(struct tty_struct *tty, struct file *filp) |
666b7793 AH |
174 | { |
175 | struct goldfish_tty *qtty = &goldfish_ttys[tty->index]; | |
176 | return tty_port_open(&qtty->port, tty, filp); | |
177 | } | |
178 | ||
d78055dc | 179 | static void goldfish_tty_close(struct tty_struct *tty, struct file *filp) |
666b7793 AH |
180 | { |
181 | tty_port_close(tty->port, tty, filp); | |
182 | } | |
183 | ||
184 | static void goldfish_tty_hangup(struct tty_struct *tty) | |
185 | { | |
186 | tty_port_hangup(tty->port); | |
187 | } | |
188 | ||
d78055dc A |
189 | static int goldfish_tty_write(struct tty_struct *tty, const unsigned char *buf, |
190 | int count) | |
666b7793 AH |
191 | { |
192 | goldfish_tty_do_write(tty->index, buf, count); | |
193 | return count; | |
194 | } | |
195 | ||
03b3b1a2 | 196 | static unsigned int goldfish_tty_write_room(struct tty_struct *tty) |
666b7793 AH |
197 | { |
198 | return 0x10000; | |
199 | } | |
200 | ||
fff4ef17 | 201 | static unsigned int goldfish_tty_chars_in_buffer(struct tty_struct *tty) |
666b7793 AH |
202 | { |
203 | struct goldfish_tty *qtty = &goldfish_ttys[tty->index]; | |
204 | void __iomem *base = qtty->base; | |
da31de35 | 205 | return __raw_readl(base + GOLDFISH_TTY_REG_BYTES_READY); |
666b7793 AH |
206 | } |
207 | ||
d78055dc A |
208 | static void goldfish_tty_console_write(struct console *co, const char *b, |
209 | unsigned count) | |
666b7793 AH |
210 | { |
211 | goldfish_tty_do_write(co->index, b, count); | |
212 | } | |
213 | ||
d78055dc A |
214 | static struct tty_driver *goldfish_tty_console_device(struct console *c, |
215 | int *index) | |
666b7793 AH |
216 | { |
217 | *index = c->index; | |
218 | return goldfish_tty_driver; | |
219 | } | |
220 | ||
221 | static int goldfish_tty_console_setup(struct console *co, char *options) | |
222 | { | |
fda2b418 | 223 | if ((unsigned)co->index >= goldfish_tty_line_count) |
666b7793 | 224 | return -ENODEV; |
a4dc9236 | 225 | if (!goldfish_ttys[co->index].base) |
666b7793 AH |
226 | return -ENODEV; |
227 | return 0; | |
228 | } | |
229 | ||
04b757df | 230 | static const struct tty_port_operations goldfish_port_ops = { |
666b7793 AH |
231 | .activate = goldfish_tty_activate, |
232 | .shutdown = goldfish_tty_shutdown | |
233 | }; | |
234 | ||
d78055dc | 235 | static const struct tty_operations goldfish_tty_ops = { |
666b7793 AH |
236 | .open = goldfish_tty_open, |
237 | .close = goldfish_tty_close, | |
238 | .hangup = goldfish_tty_hangup, | |
239 | .write = goldfish_tty_write, | |
240 | .write_room = goldfish_tty_write_room, | |
241 | .chars_in_buffer = goldfish_tty_chars_in_buffer, | |
242 | }; | |
243 | ||
244 | static int goldfish_tty_create_driver(void) | |
245 | { | |
246 | int ret; | |
247 | struct tty_driver *tty; | |
248 | ||
6396bb22 KC |
249 | goldfish_ttys = kcalloc(goldfish_tty_line_count, |
250 | sizeof(*goldfish_ttys), | |
251 | GFP_KERNEL); | |
d78055dc | 252 | if (goldfish_ttys == NULL) { |
666b7793 AH |
253 | ret = -ENOMEM; |
254 | goto err_alloc_goldfish_ttys_failed; | |
255 | } | |
256 | tty = alloc_tty_driver(goldfish_tty_line_count); | |
d78055dc | 257 | if (tty == NULL) { |
666b7793 AH |
258 | ret = -ENOMEM; |
259 | goto err_alloc_tty_driver_failed; | |
260 | } | |
261 | tty->driver_name = "goldfish"; | |
262 | tty->name = "ttyGF"; | |
263 | tty->type = TTY_DRIVER_TYPE_SERIAL; | |
264 | tty->subtype = SERIAL_TYPE_NORMAL; | |
265 | tty->init_termios = tty_std_termios; | |
d78055dc A |
266 | tty->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
267 | TTY_DRIVER_DYNAMIC_DEV; | |
666b7793 AH |
268 | tty_set_operations(tty, &goldfish_tty_ops); |
269 | ret = tty_register_driver(tty); | |
d78055dc | 270 | if (ret) |
666b7793 AH |
271 | goto err_tty_register_driver_failed; |
272 | ||
273 | goldfish_tty_driver = tty; | |
274 | return 0; | |
275 | ||
276 | err_tty_register_driver_failed: | |
277 | put_tty_driver(tty); | |
278 | err_alloc_tty_driver_failed: | |
279 | kfree(goldfish_ttys); | |
280 | goldfish_ttys = NULL; | |
281 | err_alloc_goldfish_ttys_failed: | |
282 | return ret; | |
283 | } | |
284 | ||
285 | static void goldfish_tty_delete_driver(void) | |
286 | { | |
287 | tty_unregister_driver(goldfish_tty_driver); | |
288 | put_tty_driver(goldfish_tty_driver); | |
289 | goldfish_tty_driver = NULL; | |
290 | kfree(goldfish_ttys); | |
291 | goldfish_ttys = NULL; | |
292 | } | |
293 | ||
294 | static int goldfish_tty_probe(struct platform_device *pdev) | |
295 | { | |
296 | struct goldfish_tty *qtty; | |
7157d2be | 297 | int ret = -ENODEV; |
666b7793 AH |
298 | struct resource *r; |
299 | struct device *ttydev; | |
300 | void __iomem *base; | |
301 | u32 irq; | |
465893e1 | 302 | unsigned int line; |
666b7793 AH |
303 | |
304 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
7157d2be MD |
305 | if (!r) { |
306 | pr_err("goldfish_tty: No MEM resource available!\n"); | |
307 | return -ENOMEM; | |
308 | } | |
666b7793 AH |
309 | |
310 | base = ioremap(r->start, 0x1000); | |
7157d2be MD |
311 | if (!base) { |
312 | pr_err("goldfish_tty: Unable to ioremap base!\n"); | |
313 | return -ENOMEM; | |
314 | } | |
666b7793 AH |
315 | |
316 | r = platform_get_resource(pdev, IORESOURCE_IRQ, 0); | |
7157d2be MD |
317 | if (!r) { |
318 | pr_err("goldfish_tty: No IRQ resource available!\n"); | |
666b7793 | 319 | goto err_unmap; |
7157d2be | 320 | } |
666b7793 AH |
321 | |
322 | irq = r->start; | |
323 | ||
666b7793 | 324 | mutex_lock(&goldfish_tty_lock); |
465893e1 GH |
325 | |
326 | if (pdev->id == PLATFORM_DEVID_NONE) | |
327 | line = goldfish_tty_current_line_count; | |
328 | else | |
329 | line = pdev->id; | |
330 | ||
7157d2be MD |
331 | if (line >= goldfish_tty_line_count) { |
332 | pr_err("goldfish_tty: Reached maximum tty number of %d.\n", | |
333 | goldfish_tty_current_line_count); | |
334 | ret = -ENOMEM; | |
335 | goto err_unlock; | |
336 | } | |
465893e1 | 337 | |
d78055dc | 338 | if (goldfish_tty_current_line_count == 0) { |
666b7793 | 339 | ret = goldfish_tty_create_driver(); |
d78055dc | 340 | if (ret) |
7157d2be | 341 | goto err_unlock; |
666b7793 AH |
342 | } |
343 | goldfish_tty_current_line_count++; | |
344 | ||
465893e1 | 345 | qtty = &goldfish_ttys[line]; |
666b7793 AH |
346 | spin_lock_init(&qtty->lock); |
347 | tty_port_init(&qtty->port); | |
348 | qtty->port.ops = &goldfish_port_ops; | |
349 | qtty->base = base; | |
350 | qtty->irq = irq; | |
7157d2be MD |
351 | qtty->dev = &pdev->dev; |
352 | ||
353 | /* | |
354 | * Goldfish TTY device used by the Goldfish emulator | |
355 | * should identify itself with 0, forcing the driver | |
356 | * to use virtual addresses. Goldfish TTY device | |
357 | * on Ranchu emulator (qemu2) returns 1 here and | |
358 | * driver will use physical addresses. | |
359 | */ | |
da31de35 | 360 | qtty->version = __raw_readl(base + GOLDFISH_TTY_REG_VERSION); |
7157d2be MD |
361 | |
362 | /* | |
363 | * Goldfish TTY device on Ranchu emulator (qemu2) | |
364 | * will use DMA for read/write IO operations. | |
365 | */ | |
366 | if (qtty->version > 0) { | |
367 | /* | |
368 | * Initialize dma_mask to 32-bits. | |
369 | */ | |
370 | if (!pdev->dev.dma_mask) | |
371 | pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask; | |
372 | ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32)); | |
373 | if (ret) { | |
374 | dev_err(&pdev->dev, "No suitable DMA available.\n"); | |
375 | goto err_dec_line_count; | |
376 | } | |
377 | } | |
666b7793 | 378 | |
da31de35 | 379 | __raw_writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_REG_CMD); |
666b7793 | 380 | |
d78055dc | 381 | ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED, |
7157d2be MD |
382 | "goldfish_tty", qtty); |
383 | if (ret) { | |
384 | pr_err("goldfish_tty: No IRQ available!\n"); | |
385 | goto err_dec_line_count; | |
386 | } | |
666b7793 AH |
387 | |
388 | ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver, | |
7157d2be | 389 | line, &pdev->dev); |
d78055dc | 390 | if (IS_ERR(ttydev)) { |
666b7793 AH |
391 | ret = PTR_ERR(ttydev); |
392 | goto err_tty_register_device_failed; | |
393 | } | |
394 | ||
395 | strcpy(qtty->console.name, "ttyGF"); | |
396 | qtty->console.write = goldfish_tty_console_write; | |
397 | qtty->console.device = goldfish_tty_console_device; | |
398 | qtty->console.setup = goldfish_tty_console_setup; | |
399 | qtty->console.flags = CON_PRINTBUFFER; | |
465893e1 | 400 | qtty->console.index = line; |
666b7793 | 401 | register_console(&qtty->console); |
465893e1 | 402 | platform_set_drvdata(pdev, qtty); |
666b7793 AH |
403 | |
404 | mutex_unlock(&goldfish_tty_lock); | |
405 | return 0; | |
406 | ||
666b7793 | 407 | err_tty_register_device_failed: |
1a5c2d1d | 408 | free_irq(irq, qtty); |
7157d2be | 409 | err_dec_line_count: |
666b7793 | 410 | goldfish_tty_current_line_count--; |
d78055dc | 411 | if (goldfish_tty_current_line_count == 0) |
666b7793 | 412 | goldfish_tty_delete_driver(); |
7157d2be | 413 | err_unlock: |
666b7793 AH |
414 | mutex_unlock(&goldfish_tty_lock); |
415 | err_unmap: | |
416 | iounmap(base); | |
417 | return ret; | |
418 | } | |
419 | ||
420 | static int goldfish_tty_remove(struct platform_device *pdev) | |
421 | { | |
465893e1 | 422 | struct goldfish_tty *qtty = platform_get_drvdata(pdev); |
666b7793 AH |
423 | |
424 | mutex_lock(&goldfish_tty_lock); | |
425 | ||
666b7793 | 426 | unregister_console(&qtty->console); |
465893e1 | 427 | tty_unregister_device(goldfish_tty_driver, qtty->console.index); |
666b7793 | 428 | iounmap(qtty->base); |
a4dc9236 | 429 | qtty->base = NULL; |
666b7793 AH |
430 | free_irq(qtty->irq, pdev); |
431 | goldfish_tty_current_line_count--; | |
d78055dc | 432 | if (goldfish_tty_current_line_count == 0) |
666b7793 AH |
433 | goldfish_tty_delete_driver(); |
434 | mutex_unlock(&goldfish_tty_lock); | |
435 | return 0; | |
436 | } | |
437 | ||
6a28fd2b | 438 | #ifdef CONFIG_GOLDFISH_TTY_EARLY_CONSOLE |
3840ed95 MD |
439 | static void gf_early_console_putchar(struct uart_port *port, int ch) |
440 | { | |
441 | __raw_writel(ch, port->membase); | |
442 | } | |
443 | ||
444 | static void gf_early_write(struct console *con, const char *s, unsigned int n) | |
445 | { | |
446 | struct earlycon_device *dev = con->data; | |
447 | ||
448 | uart_console_write(&dev->port, s, n, gf_early_console_putchar); | |
449 | } | |
450 | ||
451 | static int __init gf_earlycon_setup(struct earlycon_device *device, | |
452 | const char *opt) | |
453 | { | |
454 | if (!device->port.membase) | |
455 | return -ENODEV; | |
456 | ||
457 | device->con->write = gf_early_write; | |
458 | return 0; | |
459 | } | |
460 | ||
461 | OF_EARLYCON_DECLARE(early_gf_tty, "google,goldfish-tty", gf_earlycon_setup); | |
6a28fd2b | 462 | #endif |
3840ed95 | 463 | |
9b883eea MD |
464 | static const struct of_device_id goldfish_tty_of_match[] = { |
465 | { .compatible = "google,goldfish-tty", }, | |
466 | {}, | |
467 | }; | |
468 | ||
469 | MODULE_DEVICE_TABLE(of, goldfish_tty_of_match); | |
470 | ||
666b7793 AH |
471 | static struct platform_driver goldfish_tty_platform_driver = { |
472 | .probe = goldfish_tty_probe, | |
473 | .remove = goldfish_tty_remove, | |
474 | .driver = { | |
9b883eea MD |
475 | .name = "goldfish_tty", |
476 | .of_match_table = goldfish_tty_of_match, | |
666b7793 AH |
477 | } |
478 | }; | |
479 | ||
480 | module_platform_driver(goldfish_tty_platform_driver); | |
481 | ||
482 | MODULE_LICENSE("GPL v2"); |