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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Google, Inc.
4 * Copyright (C) 2012 Intel, Inc.
5 * Copyright (C) 2017 Imagination Technologies Ltd.
6 */
7
8#include <linux/console.h>
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>
16#include <linux/mod_devicetable.h>
17#include <linux/goldfish.h>
18#include <linux/mm.h>
19#include <linux/dma-mapping.h>
20#include <linux/serial_core.h>
21
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
28#define GOLDFISH_TTY_REG_VERSION 0x20
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
35
36struct 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;
43 u32 version;
44 struct device *dev;
45};
46
47static DEFINE_MUTEX(goldfish_tty_lock);
48static struct tty_driver *goldfish_tty_driver;
49static u32 goldfish_tty_line_count = 8;
50static u32 goldfish_tty_current_line_count;
51static struct goldfish_tty *goldfish_ttys;
52
53static void do_rw_io(struct goldfish_tty *qtty, unsigned long address,
54 size_t count, bool is_write)
55{
56 unsigned long irq_flags;
57 void __iomem *base = qtty->base;
58
59 spin_lock_irqsave(&qtty->lock, irq_flags);
60 gf_write_ptr((void *)address, base + GOLDFISH_TTY_REG_DATA_PTR,
61 base + GOLDFISH_TTY_REG_DATA_PTR_HIGH);
62 gf_iowrite32(count, base + GOLDFISH_TTY_REG_DATA_LEN);
63
64 if (is_write)
65 gf_iowrite32(GOLDFISH_TTY_CMD_WRITE_BUFFER,
66 base + GOLDFISH_TTY_REG_CMD);
67 else
68 gf_iowrite32(GOLDFISH_TTY_CMD_READ_BUFFER,
69 base + GOLDFISH_TTY_REG_CMD);
70
71 spin_unlock_irqrestore(&qtty->lock, irq_flags);
72}
73
74static void goldfish_tty_rw(struct goldfish_tty *qtty, unsigned long addr,
75 size_t count, bool is_write)
76{
77 dma_addr_t dma_handle;
78 enum dma_data_direction dma_dir;
79
80 dma_dir = (is_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
81 if (qtty->version > 0) {
82 /*
83 * Goldfish TTY for Ranchu platform uses
84 * physical addresses and DMA for read/write operations
85 */
86 unsigned long addr_end = addr + count;
87
88 while (addr < addr_end) {
89 unsigned long pg_end = (addr & PAGE_MASK) + PAGE_SIZE;
90 unsigned long next =
91 pg_end < addr_end ? pg_end : addr_end;
92 unsigned long avail = next - addr;
93
94 /*
95 * Map the buffer's virtual address to the DMA address
96 * so the buffer can be accessed by the device.
97 */
98 dma_handle = dma_map_single(qtty->dev, (void *)addr,
99 avail, dma_dir);
100
101 if (dma_mapping_error(qtty->dev, dma_handle)) {
102 dev_err(qtty->dev, "tty: DMA mapping error.\n");
103 return;
104 }
105 do_rw_io(qtty, dma_handle, avail, is_write);
106
107 /*
108 * Unmap the previously mapped region after
109 * the completion of the read/write operation.
110 */
111 dma_unmap_single(qtty->dev, dma_handle, avail, dma_dir);
112
113 addr += avail;
114 }
115 } else {
116 /*
117 * Old style Goldfish TTY used on the Goldfish platform
118 * uses virtual addresses.
119 */
120 do_rw_io(qtty, addr, count, is_write);
121 }
122}
123
124static void goldfish_tty_do_write(int line, const u8 *buf, size_t count)
125{
126 struct goldfish_tty *qtty = &goldfish_ttys[line];
127
128 goldfish_tty_rw(qtty, (unsigned long)buf, count, true);
129}
130
131static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id)
132{
133 struct goldfish_tty *qtty = dev_id;
134 void __iomem *base = qtty->base;
135 u8 *buf;
136 u32 count;
137
138 count = gf_ioread32(base + GOLDFISH_TTY_REG_BYTES_READY);
139 if (count == 0)
140 return IRQ_NONE;
141
142 count = tty_prepare_flip_string(&qtty->port, &buf, count);
143
144 goldfish_tty_rw(qtty, (unsigned long)buf, count, false);
145
146 tty_flip_buffer_push(&qtty->port);
147 return IRQ_HANDLED;
148}
149
150static int goldfish_tty_activate(struct tty_port *port, struct tty_struct *tty)
151{
152 struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
153 port);
154 gf_iowrite32(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
155 return 0;
156}
157
158static void goldfish_tty_shutdown(struct tty_port *port)
159{
160 struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
161 port);
162 gf_iowrite32(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
163}
164
165static int goldfish_tty_open(struct tty_struct *tty, struct file *filp)
166{
167 struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
168 return tty_port_open(&qtty->port, tty, filp);
169}
170
171static void goldfish_tty_close(struct tty_struct *tty, struct file *filp)
172{
173 tty_port_close(tty->port, tty, filp);
174}
175
176static void goldfish_tty_hangup(struct tty_struct *tty)
177{
178 tty_port_hangup(tty->port);
179}
180
181static ssize_t goldfish_tty_write(struct tty_struct *tty, const u8 *buf,
182 size_t count)
183{
184 goldfish_tty_do_write(tty->index, buf, count);
185 return count;
186}
187
188static unsigned int goldfish_tty_write_room(struct tty_struct *tty)
189{
190 return 0x10000;
191}
192
193static unsigned int goldfish_tty_chars_in_buffer(struct tty_struct *tty)
194{
195 struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
196 void __iomem *base = qtty->base;
197 return gf_ioread32(base + GOLDFISH_TTY_REG_BYTES_READY);
198}
199
200static void goldfish_tty_console_write(struct console *co, const char *b,
201 unsigned count)
202{
203 goldfish_tty_do_write(co->index, b, count);
204}
205
206static struct tty_driver *goldfish_tty_console_device(struct console *c,
207 int *index)
208{
209 *index = c->index;
210 return goldfish_tty_driver;
211}
212
213static int goldfish_tty_console_setup(struct console *co, char *options)
214{
215 if ((unsigned)co->index >= goldfish_tty_line_count)
216 return -ENODEV;
217 if (!goldfish_ttys[co->index].base)
218 return -ENODEV;
219 return 0;
220}
221
222static const struct tty_port_operations goldfish_port_ops = {
223 .activate = goldfish_tty_activate,
224 .shutdown = goldfish_tty_shutdown
225};
226
227static const struct tty_operations goldfish_tty_ops = {
228 .open = goldfish_tty_open,
229 .close = goldfish_tty_close,
230 .hangup = goldfish_tty_hangup,
231 .write = goldfish_tty_write,
232 .write_room = goldfish_tty_write_room,
233 .chars_in_buffer = goldfish_tty_chars_in_buffer,
234};
235
236static int goldfish_tty_create_driver(void)
237{
238 int ret;
239 struct tty_driver *tty;
240
241 goldfish_ttys = kcalloc(goldfish_tty_line_count,
242 sizeof(*goldfish_ttys),
243 GFP_KERNEL);
244 if (goldfish_ttys == NULL) {
245 ret = -ENOMEM;
246 goto err_alloc_goldfish_ttys_failed;
247 }
248 tty = tty_alloc_driver(goldfish_tty_line_count,
249 TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
250 TTY_DRIVER_DYNAMIC_DEV);
251 if (IS_ERR(tty)) {
252 ret = PTR_ERR(tty);
253 goto err_tty_alloc_driver_failed;
254 }
255 tty->driver_name = "goldfish";
256 tty->name = "ttyGF";
257 tty->type = TTY_DRIVER_TYPE_SERIAL;
258 tty->subtype = SERIAL_TYPE_NORMAL;
259 tty->init_termios = tty_std_termios;
260 tty_set_operations(tty, &goldfish_tty_ops);
261 ret = tty_register_driver(tty);
262 if (ret)
263 goto err_tty_register_driver_failed;
264
265 goldfish_tty_driver = tty;
266 return 0;
267
268err_tty_register_driver_failed:
269 tty_driver_kref_put(tty);
270err_tty_alloc_driver_failed:
271 kfree(goldfish_ttys);
272 goldfish_ttys = NULL;
273err_alloc_goldfish_ttys_failed:
274 return ret;
275}
276
277static void goldfish_tty_delete_driver(void)
278{
279 tty_unregister_driver(goldfish_tty_driver);
280 tty_driver_kref_put(goldfish_tty_driver);
281 goldfish_tty_driver = NULL;
282 kfree(goldfish_ttys);
283 goldfish_ttys = NULL;
284}
285
286static int goldfish_tty_probe(struct platform_device *pdev)
287{
288 struct goldfish_tty *qtty;
289 int ret = -ENODEV;
290 struct resource *r;
291 struct device *ttydev;
292 void __iomem *base;
293 int irq;
294 unsigned int line;
295
296 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
297 if (!r) {
298 pr_err("goldfish_tty: No MEM resource available!\n");
299 return -ENOMEM;
300 }
301
302 base = ioremap(r->start, 0x1000);
303 if (!base) {
304 pr_err("goldfish_tty: Unable to ioremap base!\n");
305 return -ENOMEM;
306 }
307
308 irq = platform_get_irq(pdev, 0);
309 if (irq < 0) {
310 ret = irq;
311 goto err_unmap;
312 }
313
314 mutex_lock(&goldfish_tty_lock);
315
316 if (pdev->id == PLATFORM_DEVID_NONE)
317 line = goldfish_tty_current_line_count;
318 else
319 line = pdev->id;
320
321 if (line >= goldfish_tty_line_count) {
322 pr_err("goldfish_tty: Reached maximum tty number of %d.\n",
323 goldfish_tty_current_line_count);
324 ret = -ENOMEM;
325 goto err_unlock;
326 }
327
328 if (goldfish_tty_current_line_count == 0) {
329 ret = goldfish_tty_create_driver();
330 if (ret)
331 goto err_unlock;
332 }
333 goldfish_tty_current_line_count++;
334
335 qtty = &goldfish_ttys[line];
336 spin_lock_init(&qtty->lock);
337 tty_port_init(&qtty->port);
338 qtty->port.ops = &goldfish_port_ops;
339 qtty->base = base;
340 qtty->irq = irq;
341 qtty->dev = &pdev->dev;
342
343 /*
344 * Goldfish TTY device used by the Goldfish emulator
345 * should identify itself with 0, forcing the driver
346 * to use virtual addresses. Goldfish TTY device
347 * on Ranchu emulator (qemu2) returns 1 here and
348 * driver will use physical addresses.
349 */
350 qtty->version = gf_ioread32(base + GOLDFISH_TTY_REG_VERSION);
351
352 /*
353 * Goldfish TTY device on Ranchu emulator (qemu2)
354 * will use DMA for read/write IO operations.
355 */
356 if (qtty->version > 0) {
357 /*
358 * Initialize dma_mask to 32-bits.
359 */
360 if (!pdev->dev.dma_mask)
361 pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
362 ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
363 if (ret) {
364 dev_err(&pdev->dev, "No suitable DMA available.\n");
365 goto err_dec_line_count;
366 }
367 }
368
369 gf_iowrite32(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_REG_CMD);
370
371 ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED,
372 "goldfish_tty", qtty);
373 if (ret) {
374 pr_err("goldfish_tty: No IRQ available!\n");
375 goto err_dec_line_count;
376 }
377
378 ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver,
379 line, &pdev->dev);
380 if (IS_ERR(ttydev)) {
381 ret = PTR_ERR(ttydev);
382 goto err_tty_register_device_failed;
383 }
384
385 strcpy(qtty->console.name, "ttyGF");
386 qtty->console.write = goldfish_tty_console_write;
387 qtty->console.device = goldfish_tty_console_device;
388 qtty->console.setup = goldfish_tty_console_setup;
389 qtty->console.flags = CON_PRINTBUFFER;
390 qtty->console.index = line;
391 register_console(&qtty->console);
392 platform_set_drvdata(pdev, qtty);
393
394 mutex_unlock(&goldfish_tty_lock);
395 return 0;
396
397err_tty_register_device_failed:
398 free_irq(irq, qtty);
399err_dec_line_count:
400 tty_port_destroy(&qtty->port);
401 goldfish_tty_current_line_count--;
402 if (goldfish_tty_current_line_count == 0)
403 goldfish_tty_delete_driver();
404err_unlock:
405 mutex_unlock(&goldfish_tty_lock);
406err_unmap:
407 iounmap(base);
408 return ret;
409}
410
411static int goldfish_tty_remove(struct platform_device *pdev)
412{
413 struct goldfish_tty *qtty = platform_get_drvdata(pdev);
414
415 mutex_lock(&goldfish_tty_lock);
416
417 unregister_console(&qtty->console);
418 tty_unregister_device(goldfish_tty_driver, qtty->console.index);
419 iounmap(qtty->base);
420 qtty->base = NULL;
421 free_irq(qtty->irq, qtty);
422 tty_port_destroy(&qtty->port);
423 goldfish_tty_current_line_count--;
424 if (goldfish_tty_current_line_count == 0)
425 goldfish_tty_delete_driver();
426 mutex_unlock(&goldfish_tty_lock);
427 return 0;
428}
429
430#ifdef CONFIG_GOLDFISH_TTY_EARLY_CONSOLE
431static void gf_early_console_putchar(struct uart_port *port, unsigned char ch)
432{
433 gf_iowrite32(ch, port->membase);
434}
435
436static void gf_early_write(struct console *con, const char *s, unsigned int n)
437{
438 struct earlycon_device *dev = con->data;
439
440 uart_console_write(&dev->port, s, n, gf_early_console_putchar);
441}
442
443static int __init gf_earlycon_setup(struct earlycon_device *device,
444 const char *opt)
445{
446 if (!device->port.membase)
447 return -ENODEV;
448
449 device->con->write = gf_early_write;
450 return 0;
451}
452
453OF_EARLYCON_DECLARE(early_gf_tty, "google,goldfish-tty", gf_earlycon_setup);
454#endif
455
456static const struct of_device_id goldfish_tty_of_match[] = {
457 { .compatible = "google,goldfish-tty", },
458 {},
459};
460
461MODULE_DEVICE_TABLE(of, goldfish_tty_of_match);
462
463static struct platform_driver goldfish_tty_platform_driver = {
464 .probe = goldfish_tty_probe,
465 .remove = goldfish_tty_remove,
466 .driver = {
467 .name = "goldfish_tty",
468 .of_match_table = goldfish_tty_of_match,
469 }
470};
471
472module_platform_driver(goldfish_tty_platform_driver);
473
474MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Google, Inc.
4 * Copyright (C) 2012 Intel, Inc.
5 * Copyright (C) 2017 Imagination Technologies Ltd.
6 */
7
8#include <linux/console.h>
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>
16#include <linux/goldfish.h>
17#include <linux/mm.h>
18#include <linux/dma-mapping.h>
19#include <linux/serial_core.h>
20
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
27#define GOLDFISH_TTY_REG_VERSION 0x20
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
34
35struct 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;
42 u32 version;
43 struct device *dev;
44};
45
46static DEFINE_MUTEX(goldfish_tty_lock);
47static struct tty_driver *goldfish_tty_driver;
48static u32 goldfish_tty_line_count = 8;
49static u32 goldfish_tty_current_line_count;
50static struct goldfish_tty *goldfish_ttys;
51
52static void do_rw_io(struct goldfish_tty *qtty,
53 unsigned long address,
54 unsigned int count,
55 int is_write)
56{
57 unsigned long irq_flags;
58 void __iomem *base = qtty->base;
59
60 spin_lock_irqsave(&qtty->lock, irq_flags);
61 gf_write_ptr((void *)address, base + GOLDFISH_TTY_REG_DATA_PTR,
62 base + GOLDFISH_TTY_REG_DATA_PTR_HIGH);
63 writel(count, base + GOLDFISH_TTY_REG_DATA_LEN);
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
72 spin_unlock_irqrestore(&qtty->lock, irq_flags);
73}
74
75static 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
127static 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
136static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id)
137{
138 struct goldfish_tty *qtty = dev_id;
139 void __iomem *base = qtty->base;
140 unsigned long address;
141 unsigned char *buf;
142 u32 count;
143
144 count = readl(base + GOLDFISH_TTY_REG_BYTES_READY);
145 if (count == 0)
146 return IRQ_NONE;
147
148 count = tty_prepare_flip_string(&qtty->port, &buf, count);
149
150 address = (unsigned long)(void *)buf;
151 goldfish_tty_rw(qtty, address, count, 0);
152
153 tty_schedule_flip(&qtty->port);
154 return IRQ_HANDLED;
155}
156
157static int goldfish_tty_activate(struct tty_port *port, struct tty_struct *tty)
158{
159 struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
160 port);
161 writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
162 return 0;
163}
164
165static void goldfish_tty_shutdown(struct tty_port *port)
166{
167 struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
168 port);
169 writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
170}
171
172static int goldfish_tty_open(struct tty_struct *tty, struct file *filp)
173{
174 struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
175 return tty_port_open(&qtty->port, tty, filp);
176}
177
178static void goldfish_tty_close(struct tty_struct *tty, struct file *filp)
179{
180 tty_port_close(tty->port, tty, filp);
181}
182
183static void goldfish_tty_hangup(struct tty_struct *tty)
184{
185 tty_port_hangup(tty->port);
186}
187
188static int goldfish_tty_write(struct tty_struct *tty, const unsigned char *buf,
189 int count)
190{
191 goldfish_tty_do_write(tty->index, buf, count);
192 return count;
193}
194
195static int goldfish_tty_write_room(struct tty_struct *tty)
196{
197 return 0x10000;
198}
199
200static 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;
204 return readl(base + GOLDFISH_TTY_REG_BYTES_READY);
205}
206
207static void goldfish_tty_console_write(struct console *co, const char *b,
208 unsigned count)
209{
210 goldfish_tty_do_write(co->index, b, count);
211}
212
213static struct tty_driver *goldfish_tty_console_device(struct console *c,
214 int *index)
215{
216 *index = c->index;
217 return goldfish_tty_driver;
218}
219
220static int goldfish_tty_console_setup(struct console *co, char *options)
221{
222 if ((unsigned)co->index >= goldfish_tty_line_count)
223 return -ENODEV;
224 if (!goldfish_ttys[co->index].base)
225 return -ENODEV;
226 return 0;
227}
228
229static const struct tty_port_operations goldfish_port_ops = {
230 .activate = goldfish_tty_activate,
231 .shutdown = goldfish_tty_shutdown
232};
233
234static const struct tty_operations goldfish_tty_ops = {
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
243static int goldfish_tty_create_driver(void)
244{
245 int ret;
246 struct tty_driver *tty;
247
248 goldfish_ttys = kzalloc(sizeof(*goldfish_ttys) *
249 goldfish_tty_line_count, GFP_KERNEL);
250 if (goldfish_ttys == NULL) {
251 ret = -ENOMEM;
252 goto err_alloc_goldfish_ttys_failed;
253 }
254 tty = alloc_tty_driver(goldfish_tty_line_count);
255 if (tty == NULL) {
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;
264 tty->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
265 TTY_DRIVER_DYNAMIC_DEV;
266 tty_set_operations(tty, &goldfish_tty_ops);
267 ret = tty_register_driver(tty);
268 if (ret)
269 goto err_tty_register_driver_failed;
270
271 goldfish_tty_driver = tty;
272 return 0;
273
274err_tty_register_driver_failed:
275 put_tty_driver(tty);
276err_alloc_tty_driver_failed:
277 kfree(goldfish_ttys);
278 goldfish_ttys = NULL;
279err_alloc_goldfish_ttys_failed:
280 return ret;
281}
282
283static 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
292static int goldfish_tty_probe(struct platform_device *pdev)
293{
294 struct goldfish_tty *qtty;
295 int ret = -ENODEV;
296 struct resource *r;
297 struct device *ttydev;
298 void __iomem *base;
299 u32 irq;
300 unsigned int line;
301
302 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
303 if (!r) {
304 pr_err("goldfish_tty: No MEM resource available!\n");
305 return -ENOMEM;
306 }
307
308 base = ioremap(r->start, 0x1000);
309 if (!base) {
310 pr_err("goldfish_tty: Unable to ioremap base!\n");
311 return -ENOMEM;
312 }
313
314 r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
315 if (!r) {
316 pr_err("goldfish_tty: No IRQ resource available!\n");
317 goto err_unmap;
318 }
319
320 irq = r->start;
321
322 mutex_lock(&goldfish_tty_lock);
323
324 if (pdev->id == PLATFORM_DEVID_NONE)
325 line = goldfish_tty_current_line_count;
326 else
327 line = pdev->id;
328
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 }
335
336 if (goldfish_tty_current_line_count == 0) {
337 ret = goldfish_tty_create_driver();
338 if (ret)
339 goto err_unlock;
340 }
341 goldfish_tty_current_line_count++;
342
343 qtty = &goldfish_ttys[line];
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;
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 }
376
377 writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_REG_CMD);
378
379 ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED,
380 "goldfish_tty", qtty);
381 if (ret) {
382 pr_err("goldfish_tty: No IRQ available!\n");
383 goto err_dec_line_count;
384 }
385
386 ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver,
387 line, &pdev->dev);
388 if (IS_ERR(ttydev)) {
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;
398 qtty->console.index = line;
399 register_console(&qtty->console);
400 platform_set_drvdata(pdev, qtty);
401
402 mutex_unlock(&goldfish_tty_lock);
403 return 0;
404
405err_tty_register_device_failed:
406 free_irq(irq, qtty);
407err_dec_line_count:
408 goldfish_tty_current_line_count--;
409 if (goldfish_tty_current_line_count == 0)
410 goldfish_tty_delete_driver();
411err_unlock:
412 mutex_unlock(&goldfish_tty_lock);
413err_unmap:
414 iounmap(base);
415 return ret;
416}
417
418static int goldfish_tty_remove(struct platform_device *pdev)
419{
420 struct goldfish_tty *qtty = platform_get_drvdata(pdev);
421
422 mutex_lock(&goldfish_tty_lock);
423
424 unregister_console(&qtty->console);
425 tty_unregister_device(goldfish_tty_driver, qtty->console.index);
426 iounmap(qtty->base);
427 qtty->base = NULL;
428 free_irq(qtty->irq, pdev);
429 goldfish_tty_current_line_count--;
430 if (goldfish_tty_current_line_count == 0)
431 goldfish_tty_delete_driver();
432 mutex_unlock(&goldfish_tty_lock);
433 return 0;
434}
435
436#ifdef CONFIG_GOLDFISH_TTY_EARLY_CONSOLE
437static void gf_early_console_putchar(struct uart_port *port, int ch)
438{
439 __raw_writel(ch, port->membase);
440}
441
442static void gf_early_write(struct console *con, const char *s, unsigned int n)
443{
444 struct earlycon_device *dev = con->data;
445
446 uart_console_write(&dev->port, s, n, gf_early_console_putchar);
447}
448
449static int __init gf_earlycon_setup(struct earlycon_device *device,
450 const char *opt)
451{
452 if (!device->port.membase)
453 return -ENODEV;
454
455 device->con->write = gf_early_write;
456 return 0;
457}
458
459OF_EARLYCON_DECLARE(early_gf_tty, "google,goldfish-tty", gf_earlycon_setup);
460#endif
461
462static const struct of_device_id goldfish_tty_of_match[] = {
463 { .compatible = "google,goldfish-tty", },
464 {},
465};
466
467MODULE_DEVICE_TABLE(of, goldfish_tty_of_match);
468
469static struct platform_driver goldfish_tty_platform_driver = {
470 .probe = goldfish_tty_probe,
471 .remove = goldfish_tty_remove,
472 .driver = {
473 .name = "goldfish_tty",
474 .of_match_table = goldfish_tty_of_match,
475 }
476};
477
478module_platform_driver(goldfish_tty_platform_driver);
479
480MODULE_LICENSE("GPL v2");