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666b7793 AH |
1 | /* |
2 | * Copyright (C) 2007 Google, Inc. | |
3 | * Copyright (C) 2012 Intel, Inc. | |
4 | * | |
5 | * This software is licensed under the terms of the GNU General Public | |
6 | * License version 2, as published by the Free Software Foundation, and | |
7 | * may be copied, distributed, and modified under those terms. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | */ | |
15 | ||
16 | #include <linux/console.h> | |
17 | #include <linux/init.h> | |
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> | |
25 | ||
26 | enum { | |
27 | GOLDFISH_TTY_PUT_CHAR = 0x00, | |
28 | GOLDFISH_TTY_BYTES_READY = 0x04, | |
29 | GOLDFISH_TTY_CMD = 0x08, | |
30 | ||
31 | GOLDFISH_TTY_DATA_PTR = 0x10, | |
32 | GOLDFISH_TTY_DATA_LEN = 0x14, | |
33 | ||
34 | GOLDFISH_TTY_CMD_INT_DISABLE = 0, | |
35 | GOLDFISH_TTY_CMD_INT_ENABLE = 1, | |
36 | GOLDFISH_TTY_CMD_WRITE_BUFFER = 2, | |
37 | GOLDFISH_TTY_CMD_READ_BUFFER = 3, | |
38 | }; | |
39 | ||
40 | struct goldfish_tty { | |
41 | struct tty_port port; | |
42 | spinlock_t lock; | |
43 | void __iomem *base; | |
44 | u32 irq; | |
45 | int opencount; | |
46 | struct console console; | |
47 | }; | |
48 | ||
49 | static DEFINE_MUTEX(goldfish_tty_lock); | |
50 | static struct tty_driver *goldfish_tty_driver; | |
51 | static u32 goldfish_tty_line_count = 8; | |
52 | static u32 goldfish_tty_current_line_count; | |
53 | static struct goldfish_tty *goldfish_ttys; | |
54 | ||
55 | static void goldfish_tty_do_write(int line, const char *buf, unsigned count) | |
56 | { | |
57 | unsigned long irq_flags; | |
58 | struct goldfish_tty *qtty = &goldfish_ttys[line]; | |
59 | void __iomem *base = qtty->base; | |
60 | spin_lock_irqsave(&qtty->lock, irq_flags); | |
61 | writel((u32)buf, base + GOLDFISH_TTY_DATA_PTR); | |
62 | writel(count, base + GOLDFISH_TTY_DATA_LEN); | |
63 | writel(GOLDFISH_TTY_CMD_WRITE_BUFFER, base + GOLDFISH_TTY_CMD); | |
64 | spin_unlock_irqrestore(&qtty->lock, irq_flags); | |
65 | } | |
66 | ||
67 | static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id) | |
68 | { | |
69 | struct platform_device *pdev = dev_id; | |
70 | struct goldfish_tty *qtty = &goldfish_ttys[pdev->id]; | |
71 | void __iomem *base = qtty->base; | |
72 | unsigned long irq_flags; | |
73 | unsigned char *buf; | |
74 | u32 count; | |
666b7793 AH |
75 | |
76 | count = readl(base + GOLDFISH_TTY_BYTES_READY); | |
77 | if(count == 0) | |
78 | return IRQ_NONE; | |
79 | ||
ebcf0981 AC |
80 | count = tty_prepare_flip_string(&qtty->port, &buf, count); |
81 | spin_lock_irqsave(&qtty->lock, irq_flags); | |
82 | writel((u32)buf, base + GOLDFISH_TTY_DATA_PTR); | |
83 | writel(count, base + GOLDFISH_TTY_DATA_LEN); | |
84 | writel(GOLDFISH_TTY_CMD_READ_BUFFER, base + GOLDFISH_TTY_CMD); | |
85 | spin_unlock_irqrestore(&qtty->lock, irq_flags); | |
86 | tty_schedule_flip(&qtty->port); | |
666b7793 AH |
87 | return IRQ_HANDLED; |
88 | } | |
89 | ||
90 | static int goldfish_tty_activate(struct tty_port *port, struct tty_struct *tty) | |
91 | { | |
92 | struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, port); | |
93 | writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_CMD); | |
94 | return 0; | |
95 | } | |
96 | ||
97 | static void goldfish_tty_shutdown(struct tty_port *port) | |
98 | { | |
99 | struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, port); | |
100 | writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_CMD); | |
101 | } | |
102 | ||
103 | static int goldfish_tty_open(struct tty_struct * tty, struct file * filp) | |
104 | { | |
105 | struct goldfish_tty *qtty = &goldfish_ttys[tty->index]; | |
106 | return tty_port_open(&qtty->port, tty, filp); | |
107 | } | |
108 | ||
109 | static void goldfish_tty_close(struct tty_struct * tty, struct file * filp) | |
110 | { | |
111 | tty_port_close(tty->port, tty, filp); | |
112 | } | |
113 | ||
114 | static void goldfish_tty_hangup(struct tty_struct *tty) | |
115 | { | |
116 | tty_port_hangup(tty->port); | |
117 | } | |
118 | ||
119 | static int goldfish_tty_write(struct tty_struct * tty, const unsigned char *buf, int count) | |
120 | { | |
121 | goldfish_tty_do_write(tty->index, buf, count); | |
122 | return count; | |
123 | } | |
124 | ||
125 | static int goldfish_tty_write_room(struct tty_struct *tty) | |
126 | { | |
127 | return 0x10000; | |
128 | } | |
129 | ||
130 | static int goldfish_tty_chars_in_buffer(struct tty_struct *tty) | |
131 | { | |
132 | struct goldfish_tty *qtty = &goldfish_ttys[tty->index]; | |
133 | void __iomem *base = qtty->base; | |
134 | return readl(base + GOLDFISH_TTY_BYTES_READY); | |
135 | } | |
136 | ||
137 | static void goldfish_tty_console_write(struct console *co, const char *b, unsigned count) | |
138 | { | |
139 | goldfish_tty_do_write(co->index, b, count); | |
140 | } | |
141 | ||
142 | static struct tty_driver *goldfish_tty_console_device(struct console *c, int *index) | |
143 | { | |
144 | *index = c->index; | |
145 | return goldfish_tty_driver; | |
146 | } | |
147 | ||
148 | static int goldfish_tty_console_setup(struct console *co, char *options) | |
149 | { | |
150 | if((unsigned)co->index > goldfish_tty_line_count) | |
151 | return -ENODEV; | |
152 | if(goldfish_ttys[co->index].base == 0) | |
153 | return -ENODEV; | |
154 | return 0; | |
155 | } | |
156 | ||
157 | static struct tty_port_operations goldfish_port_ops = { | |
158 | .activate = goldfish_tty_activate, | |
159 | .shutdown = goldfish_tty_shutdown | |
160 | }; | |
161 | ||
162 | static struct tty_operations goldfish_tty_ops = { | |
163 | .open = goldfish_tty_open, | |
164 | .close = goldfish_tty_close, | |
165 | .hangup = goldfish_tty_hangup, | |
166 | .write = goldfish_tty_write, | |
167 | .write_room = goldfish_tty_write_room, | |
168 | .chars_in_buffer = goldfish_tty_chars_in_buffer, | |
169 | }; | |
170 | ||
171 | static int goldfish_tty_create_driver(void) | |
172 | { | |
173 | int ret; | |
174 | struct tty_driver *tty; | |
175 | ||
176 | goldfish_ttys = kzalloc(sizeof(*goldfish_ttys) * goldfish_tty_line_count, GFP_KERNEL); | |
177 | if(goldfish_ttys == NULL) { | |
178 | ret = -ENOMEM; | |
179 | goto err_alloc_goldfish_ttys_failed; | |
180 | } | |
181 | tty = alloc_tty_driver(goldfish_tty_line_count); | |
182 | if(tty == NULL) { | |
183 | ret = -ENOMEM; | |
184 | goto err_alloc_tty_driver_failed; | |
185 | } | |
186 | tty->driver_name = "goldfish"; | |
187 | tty->name = "ttyGF"; | |
188 | tty->type = TTY_DRIVER_TYPE_SERIAL; | |
189 | tty->subtype = SERIAL_TYPE_NORMAL; | |
190 | tty->init_termios = tty_std_termios; | |
191 | tty->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; | |
192 | tty_set_operations(tty, &goldfish_tty_ops); | |
193 | ret = tty_register_driver(tty); | |
194 | if(ret) | |
195 | goto err_tty_register_driver_failed; | |
196 | ||
197 | goldfish_tty_driver = tty; | |
198 | return 0; | |
199 | ||
200 | err_tty_register_driver_failed: | |
201 | put_tty_driver(tty); | |
202 | err_alloc_tty_driver_failed: | |
203 | kfree(goldfish_ttys); | |
204 | goldfish_ttys = NULL; | |
205 | err_alloc_goldfish_ttys_failed: | |
206 | return ret; | |
207 | } | |
208 | ||
209 | static void goldfish_tty_delete_driver(void) | |
210 | { | |
211 | tty_unregister_driver(goldfish_tty_driver); | |
212 | put_tty_driver(goldfish_tty_driver); | |
213 | goldfish_tty_driver = NULL; | |
214 | kfree(goldfish_ttys); | |
215 | goldfish_ttys = NULL; | |
216 | } | |
217 | ||
218 | static int goldfish_tty_probe(struct platform_device *pdev) | |
219 | { | |
220 | struct goldfish_tty *qtty; | |
221 | int ret = -EINVAL; | |
222 | int i; | |
223 | struct resource *r; | |
224 | struct device *ttydev; | |
225 | void __iomem *base; | |
226 | u32 irq; | |
227 | ||
228 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
229 | if(r == NULL) | |
230 | return -EINVAL; | |
231 | ||
232 | base = ioremap(r->start, 0x1000); | |
233 | if (base == NULL) | |
234 | pr_err("goldfish_tty: unable to remap base\n"); | |
235 | ||
236 | r = platform_get_resource(pdev, IORESOURCE_IRQ, 0); | |
237 | if(r == NULL) | |
238 | goto err_unmap; | |
239 | ||
240 | irq = r->start; | |
241 | ||
242 | if(pdev->id >= goldfish_tty_line_count) | |
243 | goto err_unmap; | |
244 | ||
245 | mutex_lock(&goldfish_tty_lock); | |
246 | if(goldfish_tty_current_line_count == 0) { | |
247 | ret = goldfish_tty_create_driver(); | |
248 | if(ret) | |
249 | goto err_create_driver_failed; | |
250 | } | |
251 | goldfish_tty_current_line_count++; | |
252 | ||
253 | qtty = &goldfish_ttys[pdev->id]; | |
254 | spin_lock_init(&qtty->lock); | |
255 | tty_port_init(&qtty->port); | |
256 | qtty->port.ops = &goldfish_port_ops; | |
257 | qtty->base = base; | |
258 | qtty->irq = irq; | |
259 | ||
260 | writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_CMD); | |
261 | ||
262 | ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED, "goldfish_tty", pdev); | |
263 | if(ret) | |
264 | goto err_request_irq_failed; | |
265 | ||
266 | ||
267 | ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver, | |
268 | pdev->id, &pdev->dev); | |
269 | if(IS_ERR(ttydev)) { | |
270 | ret = PTR_ERR(ttydev); | |
271 | goto err_tty_register_device_failed; | |
272 | } | |
273 | ||
274 | strcpy(qtty->console.name, "ttyGF"); | |
275 | qtty->console.write = goldfish_tty_console_write; | |
276 | qtty->console.device = goldfish_tty_console_device; | |
277 | qtty->console.setup = goldfish_tty_console_setup; | |
278 | qtty->console.flags = CON_PRINTBUFFER; | |
279 | qtty->console.index = pdev->id; | |
280 | register_console(&qtty->console); | |
281 | ||
282 | mutex_unlock(&goldfish_tty_lock); | |
283 | return 0; | |
284 | ||
285 | tty_unregister_device(goldfish_tty_driver, i); | |
286 | err_tty_register_device_failed: | |
287 | free_irq(irq, pdev); | |
288 | err_request_irq_failed: | |
289 | goldfish_tty_current_line_count--; | |
290 | if(goldfish_tty_current_line_count == 0) | |
291 | goldfish_tty_delete_driver(); | |
292 | err_create_driver_failed: | |
293 | mutex_unlock(&goldfish_tty_lock); | |
294 | err_unmap: | |
295 | iounmap(base); | |
296 | return ret; | |
297 | } | |
298 | ||
299 | static int goldfish_tty_remove(struct platform_device *pdev) | |
300 | { | |
301 | struct goldfish_tty *qtty; | |
302 | ||
303 | mutex_lock(&goldfish_tty_lock); | |
304 | ||
305 | qtty = &goldfish_ttys[pdev->id]; | |
306 | unregister_console(&qtty->console); | |
307 | tty_unregister_device(goldfish_tty_driver, pdev->id); | |
308 | iounmap(qtty->base); | |
309 | qtty->base = 0; | |
310 | free_irq(qtty->irq, pdev); | |
311 | goldfish_tty_current_line_count--; | |
312 | if(goldfish_tty_current_line_count == 0) | |
313 | goldfish_tty_delete_driver(); | |
314 | mutex_unlock(&goldfish_tty_lock); | |
315 | return 0; | |
316 | } | |
317 | ||
318 | static struct platform_driver goldfish_tty_platform_driver = { | |
319 | .probe = goldfish_tty_probe, | |
320 | .remove = goldfish_tty_remove, | |
321 | .driver = { | |
322 | .name = "goldfish_tty" | |
323 | } | |
324 | }; | |
325 | ||
326 | module_platform_driver(goldfish_tty_platform_driver); | |
327 | ||
328 | MODULE_LICENSE("GPL v2"); |