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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
26enum {
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
40struct 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
49static DEFINE_MUTEX(goldfish_tty_lock);
50static struct tty_driver *goldfish_tty_driver;
51static u32 goldfish_tty_line_count = 8;
52static u32 goldfish_tty_current_line_count;
53static struct goldfish_tty *goldfish_ttys;
54
55static 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
67static 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;
75
76 count = readl(base + GOLDFISH_TTY_BYTES_READY);
77 if(count == 0)
78 return IRQ_NONE;
79
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);
87 return IRQ_HANDLED;
88}
89
90static 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
97static 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
103static 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
109static void goldfish_tty_close(struct tty_struct * tty, struct file * filp)
110{
111 tty_port_close(tty->port, tty, filp);
112}
113
114static void goldfish_tty_hangup(struct tty_struct *tty)
115{
116 tty_port_hangup(tty->port);
117}
118
119static 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
125static int goldfish_tty_write_room(struct tty_struct *tty)
126{
127 return 0x10000;
128}
129
130static 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
137static 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
142static struct tty_driver *goldfish_tty_console_device(struct console *c, int *index)
143{
144 *index = c->index;
145 return goldfish_tty_driver;
146}
147
148static 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
157static struct tty_port_operations goldfish_port_ops = {
158 .activate = goldfish_tty_activate,
159 .shutdown = goldfish_tty_shutdown
160};
161
162static 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
171static 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
200err_tty_register_driver_failed:
201 put_tty_driver(tty);
202err_alloc_tty_driver_failed:
203 kfree(goldfish_ttys);
204 goldfish_ttys = NULL;
205err_alloc_goldfish_ttys_failed:
206 return ret;
207}
208
209static 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
218static 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);
286err_tty_register_device_failed:
287 free_irq(irq, pdev);
288err_request_irq_failed:
289 goldfish_tty_current_line_count--;
290 if(goldfish_tty_current_line_count == 0)
291 goldfish_tty_delete_driver();
292err_create_driver_failed:
293 mutex_unlock(&goldfish_tty_lock);
294err_unmap:
295 iounmap(base);
296 return ret;
297}
298
299static 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
318static 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
326module_platform_driver(goldfish_tty_platform_driver);
327
328MODULE_LICENSE("GPL v2");
329
