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19#include <linux/completion.h>
20#include <linux/ctype.h>
21#include <linux/delay.h>
22#include <linux/init.h>
23#include <linux/interrupt.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/serio.h>
27#include <linux/slab.h>
28#include <linux/spinlock.h>
29#include <linux/time.h>
30#include <linux/workqueue.h>
31
32#include <media/cec.h>
33
34MODULE_AUTHOR("Hans Verkuil <hverkuil@xs4all.nl>");
35MODULE_DESCRIPTION("RainShadow Tech HDMI CEC driver");
36MODULE_LICENSE("GPL");
37
38#define DATA_SIZE 256
39
40struct rain {
41 struct device *dev;
42 struct serio *serio;
43 struct cec_adapter *adap;
44 struct completion cmd_done;
45 struct work_struct work;
46
47
48 char buf[DATA_SIZE];
49 unsigned int buf_rd_idx;
50 unsigned int buf_wr_idx;
51 unsigned int buf_len;
52 spinlock_t buf_lock;
53
54
55 char cmd[DATA_SIZE];
56 unsigned int cmd_idx;
57 bool cmd_started;
58
59
60 char cmd_reply[DATA_SIZE];
61
62 struct mutex write_lock;
63};
64
65static void rain_process_msg(struct rain *rain)
66{
67 struct cec_msg msg = {};
68 const char *cmd = rain->cmd + 3;
69 int stat = -1;
70
71 for (; *cmd; cmd++) {
72 if (!isxdigit(*cmd))
73 continue;
74 if (isxdigit(cmd[0]) && isxdigit(cmd[1])) {
75 if (msg.len == CEC_MAX_MSG_SIZE)
76 break;
77 if (hex2bin(msg.msg + msg.len, cmd, 1))
78 continue;
79 msg.len++;
80 cmd++;
81 continue;
82 }
83 if (!cmd[1])
84 stat = hex_to_bin(cmd[0]);
85 break;
86 }
87
88 if (rain->cmd[0] == 'R') {
89 if (stat == 1 || stat == 2)
90 cec_received_msg(rain->adap, &msg);
91 return;
92 }
93
94 switch (stat) {
95 case 1:
96 cec_transmit_attempt_done(rain->adap, CEC_TX_STATUS_OK);
97 break;
98 case 2:
99 cec_transmit_attempt_done(rain->adap, CEC_TX_STATUS_NACK);
100 break;
101 default:
102 cec_transmit_attempt_done(rain->adap, CEC_TX_STATUS_LOW_DRIVE);
103 break;
104 }
105}
106
107static void rain_irq_work_handler(struct work_struct *work)
108{
109 struct rain *rain =
110 container_of(work, struct rain, work);
111
112 while (true) {
113 unsigned long flags;
114 char data;
115
116 spin_lock_irqsave(&rain->buf_lock, flags);
117 if (!rain->buf_len) {
118 spin_unlock_irqrestore(&rain->buf_lock, flags);
119 break;
120 }
121
122 data = rain->buf[rain->buf_rd_idx];
123 rain->buf_len--;
124 rain->buf_rd_idx = (rain->buf_rd_idx + 1) & 0xff;
125
126 spin_unlock_irqrestore(&rain->buf_lock, flags);
127
128 if (!rain->cmd_started && data != '?')
129 continue;
130
131 switch (data) {
132 case '\r':
133 rain->cmd[rain->cmd_idx] = '\0';
134 dev_dbg(rain->dev, "received: %s\n", rain->cmd);
135 if (!memcmp(rain->cmd, "REC", 3) ||
136 !memcmp(rain->cmd, "STA", 3)) {
137 rain_process_msg(rain);
138 } else {
139 strscpy(rain->cmd_reply, rain->cmd,
140 sizeof(rain->cmd_reply));
141 complete(&rain->cmd_done);
142 }
143 rain->cmd_idx = 0;
144 rain->cmd_started = false;
145 break;
146
147 case '\n':
148 rain->cmd_idx = 0;
149 rain->cmd_started = false;
150 break;
151
152 case '?':
153 rain->cmd_idx = 0;
154 rain->cmd_started = true;
155 break;
156
157 default:
158 if (rain->cmd_idx >= DATA_SIZE - 1) {
159 dev_dbg(rain->dev,
160 "throwing away %d bytes of garbage\n", rain->cmd_idx);
161 rain->cmd_idx = 0;
162 }
163 rain->cmd[rain->cmd_idx++] = data;
164 break;
165 }
166 }
167}
168
169static irqreturn_t rain_interrupt(struct serio *serio, unsigned char data,
170 unsigned int flags)
171{
172 struct rain *rain = serio_get_drvdata(serio);
173
174 if (rain->buf_len == DATA_SIZE) {
175 dev_warn_once(rain->dev, "buffer overflow\n");
176 return IRQ_HANDLED;
177 }
178 spin_lock(&rain->buf_lock);
179 rain->buf_len++;
180 rain->buf[rain->buf_wr_idx] = data;
181 rain->buf_wr_idx = (rain->buf_wr_idx + 1) & 0xff;
182 spin_unlock(&rain->buf_lock);
183 schedule_work(&rain->work);
184 return IRQ_HANDLED;
185}
186
187static void rain_disconnect(struct serio *serio)
188{
189 struct rain *rain = serio_get_drvdata(serio);
190
191 cancel_work_sync(&rain->work);
192 cec_unregister_adapter(rain->adap);
193 dev_info(&serio->dev, "disconnected\n");
194 serio_close(serio);
195 serio_set_drvdata(serio, NULL);
196 kfree(rain);
197}
198
199static int rain_send(struct rain *rain, const char *command)
200{
201 int err = serio_write(rain->serio, '!');
202
203 dev_dbg(rain->dev, "send: %s\n", command);
204 while (!err && *command)
205 err = serio_write(rain->serio, *command++);
206 if (!err)
207 err = serio_write(rain->serio, '~');
208
209 return err;
210}
211
212static int rain_send_and_wait(struct rain *rain,
213 const char *cmd, const char *reply)
214{
215 int err;
216
217 init_completion(&rain->cmd_done);
218
219 mutex_lock(&rain->write_lock);
220 err = rain_send(rain, cmd);
221 if (err)
222 goto err;
223
224 if (!wait_for_completion_timeout(&rain->cmd_done, HZ)) {
225 err = -ETIMEDOUT;
226 goto err;
227 }
228 if (reply && strncmp(rain->cmd_reply, reply, strlen(reply))) {
229 dev_dbg(rain->dev,
230 "transmit of '%s': received '%s' instead of '%s'\n",
231 cmd, rain->cmd_reply, reply);
232 err = -EIO;
233 }
234err:
235 mutex_unlock(&rain->write_lock);
236 return err;
237}
238
239static int rain_setup(struct rain *rain, struct serio *serio,
240 struct cec_log_addrs *log_addrs, u16 *pa)
241{
242 int err;
243
244 err = rain_send_and_wait(rain, "R", "REV");
245 if (err)
246 return err;
247 dev_info(rain->dev, "Firmware version %s\n", rain->cmd_reply + 4);
248
249 err = rain_send_and_wait(rain, "Q 1", "QTY");
250 if (err)
251 return err;
252 err = rain_send_and_wait(rain, "c0000", "CFG");
253 if (err)
254 return err;
255 return rain_send_and_wait(rain, "A F 0000", "ADR");
256}
257
258static int rain_cec_adap_enable(struct cec_adapter *adap, bool enable)
259{
260 return 0;
261}
262
263static int rain_cec_adap_log_addr(struct cec_adapter *adap, u8 log_addr)
264{
265 struct rain *rain = cec_get_drvdata(adap);
266 u8 cmd[16];
267
268 if (log_addr == CEC_LOG_ADDR_INVALID)
269 log_addr = CEC_LOG_ADDR_UNREGISTERED;
270 snprintf(cmd, sizeof(cmd), "A %x", log_addr);
271 return rain_send_and_wait(rain, cmd, "ADR");
272}
273
274static int rain_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
275 u32 signal_free_time, struct cec_msg *msg)
276{
277 struct rain *rain = cec_get_drvdata(adap);
278 char cmd[2 * CEC_MAX_MSG_SIZE + 16];
279 unsigned int i;
280 int err;
281
282 if (msg->len == 1) {
283 snprintf(cmd, sizeof(cmd), "x%x", cec_msg_destination(msg));
284 } else {
285 char hex[3];
286
287 snprintf(cmd, sizeof(cmd), "x%x %02x ",
288 cec_msg_destination(msg), msg->msg[1]);
289 for (i = 2; i < msg->len; i++) {
290 snprintf(hex, sizeof(hex), "%02x", msg->msg[i]);
291 strlcat(cmd, hex, sizeof(cmd));
292 }
293 }
294 mutex_lock(&rain->write_lock);
295 err = rain_send(rain, cmd);
296 mutex_unlock(&rain->write_lock);
297 return err;
298}
299
300static const struct cec_adap_ops rain_cec_adap_ops = {
301 .adap_enable = rain_cec_adap_enable,
302 .adap_log_addr = rain_cec_adap_log_addr,
303 .adap_transmit = rain_cec_adap_transmit,
304};
305
306static int rain_connect(struct serio *serio, struct serio_driver *drv)
307{
308 u32 caps = CEC_CAP_DEFAULTS | CEC_CAP_PHYS_ADDR | CEC_CAP_MONITOR_ALL;
309 struct rain *rain;
310 int err = -ENOMEM;
311 struct cec_log_addrs log_addrs = {};
312 u16 pa = CEC_PHYS_ADDR_INVALID;
313
314 rain = kzalloc(sizeof(*rain), GFP_KERNEL);
315
316 if (!rain)
317 return -ENOMEM;
318
319 rain->serio = serio;
320 rain->adap = cec_allocate_adapter(&rain_cec_adap_ops, rain,
321 dev_name(&serio->dev), caps, 1);
322 err = PTR_ERR_OR_ZERO(rain->adap);
323 if (err < 0)
324 goto free_device;
325
326 rain->dev = &serio->dev;
327 serio_set_drvdata(serio, rain);
328 INIT_WORK(&rain->work, rain_irq_work_handler);
329 mutex_init(&rain->write_lock);
330 spin_lock_init(&rain->buf_lock);
331
332 err = serio_open(serio, drv);
333 if (err)
334 goto delete_adap;
335
336 err = rain_setup(rain, serio, &log_addrs, &pa);
337 if (err)
338 goto close_serio;
339
340 err = cec_register_adapter(rain->adap, &serio->dev);
341 if (err < 0)
342 goto close_serio;
343
344 rain->dev = &rain->adap->devnode.dev;
345 return 0;
346
347close_serio:
348 serio_close(serio);
349delete_adap:
350 cec_delete_adapter(rain->adap);
351 serio_set_drvdata(serio, NULL);
352free_device:
353 kfree(rain);
354 return err;
355}
356
357static const struct serio_device_id rain_serio_ids[] = {
358 {
359 .type = SERIO_RS232,
360 .proto = SERIO_RAINSHADOW_CEC,
361 .id = SERIO_ANY,
362 .extra = SERIO_ANY,
363 },
364 { 0 }
365};
366
367MODULE_DEVICE_TABLE(serio, rain_serio_ids);
368
369static struct serio_driver rain_drv = {
370 .driver = {
371 .name = "rainshadow-cec",
372 },
373 .description = "RainShadow Tech HDMI CEC driver",
374 .id_table = rain_serio_ids,
375 .interrupt = rain_interrupt,
376 .connect = rain_connect,
377 .disconnect = rain_disconnect,
378};
379
380module_serio_driver(rain_drv);
381
