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V4L/DVB: staging/lirc: add lirc_ite8709 driver

Jarod Wilson committed 16 years ago

Commit 85cb01a1 parent 4cb613a1 file · +542 −0Browse files

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drivers/staging/lirc/lirc_ite8709.c+542−0
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1+/*
2+ * LIRC driver for ITE8709 CIR port
3+ *
4+ * Copyright (C) 2008 Grégory Lardière <spmf2004-lirc@yahoo.fr>
5+ *
6+ * This program is free software; you can redistribute it and/or
7+ * modify it under the terms of the GNU General Public License as
8+ * published by the Free Software Foundation; either version 2 of the
9+ * License, or (at your option) any later version.
10+ *
11+ * This program is distributed in the hope that it will be useful, but
12+ * WITHOUT ANY WARRANTY; without even the implied warranty of
13+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14+ * General Public License for more details.
15+ *
16+ * You should have received a copy of the GNU General Public License
17+ * along with this program; if not, write to the Free Software
18+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
19+ * USA
20+ */
21+
22+#include <linux/module.h>
23+#include <linux/interrupt.h>
24+#include <linux/sched.h>
25+#include <linux/delay.h>
26+#include <linux/pnp.h>
27+#include <linux/io.h>
28+
29+#include <media/lirc.h>
30+#include <media/lirc_dev.h>
31+
32+#define LIRC_DRIVER_NAME "lirc_ite8709"
33+
34+#define BUF_CHUNK_SIZE sizeof(int)
35+#define BUF_SIZE (128*BUF_CHUNK_SIZE)
36+
37+/*
38+ * The ITE8709 device seems to be the combination of IT8512 superIO chip and
39+ * a specific firmware running on the IT8512's embedded micro-controller.
40+ * In addition of the embedded micro-controller, the IT8512 chip contains a
41+ * CIR module and several other modules. A few modules are directly accessible
42+ * by the host CPU, but most of them are only accessible by the
43+ * micro-controller. The CIR module is only accessible by the micro-controller.
44+ * The battery-backed SRAM module is accessible by the host CPU and the
45+ * micro-controller. So one of the MC's firmware role is to act as a bridge
46+ * between the host CPU and the CIR module. The firmware implements a kind of
47+ * communication protocol using the SRAM module as a shared memory. The IT8512
48+ * specification is publicly available on ITE's web site, but the communication
49+ * protocol is not, so it was reverse-engineered.
50+ */
51+
52+/* ITE8709 Registers addresses and values (reverse-engineered) */
53+#define ITE8709_MODE 0x1a
54+#define ITE8709_REG_ADR 0x1b
55+#define ITE8709_REG_VAL 0x1c
56+#define ITE8709_IIR 0x1e /* Interrupt identification register */
57+#define ITE8709_RFSR 0x1f /* Receiver FIFO status register */
58+#define ITE8709_FIFO_START 0x20
59+
60+#define ITE8709_MODE_READY 0X00
61+#define ITE8709_MODE_WRITE 0X01
62+#define ITE8709_MODE_READ 0X02
63+#define ITE8709_IIR_RDAI 0x02 /* Receiver data available interrupt */
64+#define ITE8709_IIR_RFOI 0x04 /* Receiver FIFO overrun interrupt */
65+#define ITE8709_RFSR_MASK 0x3f /* FIFO byte count mask */
66+
67+/*
68+ * IT8512 CIR-module registers addresses and values
69+ * (from IT8512 E/F specification v0.4.1)
70+ */
71+#define IT8512_REG_MSTCR 0x01 /* Master control register */
72+#define IT8512_REG_IER 0x02 /* Interrupt enable register */
73+#define IT8512_REG_CFR 0x04 /* Carrier frequency register */
74+#define IT8512_REG_RCR 0x05 /* Receive control register */
75+#define IT8512_REG_BDLR 0x08 /* Baud rate divisor low byte register */
76+#define IT8512_REG_BDHR 0x09 /* Baud rate divisor high byte register */
77+
78+#define IT8512_MSTCR_RESET 0x01 /* Reset registers to default value */
79+#define IT8512_MSTCR_FIFOCLR 0x02 /* Clear FIFO */
80+#define IT8512_MSTCR_FIFOTL_7 0x04 /* FIFO threshold level : 7 */
81+#define IT8512_MSTCR_FIFOTL_25 0x0c /* FIFO threshold level : 25 */
82+#define IT8512_IER_RDAIE 0x02 /* Enable data interrupt request */
83+#define IT8512_IER_RFOIE 0x04 /* Enable FIFO overrun interrupt req */
84+#define IT8512_IER_IEC 0x80 /* Enable interrupt request */
85+#define IT8512_CFR_CF_36KHZ 0x09 /* Carrier freq : low speed, 36kHz */
86+#define IT8512_RCR_RXDCR_1 0x01 /* Demodulation carrier range : 1 */
87+#define IT8512_RCR_RXACT 0x08 /* Receiver active */
88+#define IT8512_RCR_RXEN 0x80 /* Receiver enable */
89+#define IT8512_BDR_6 6 /* Baud rate divisor : 6 */
90+
91+/* Actual values used by this driver */
92+#define CFG_FIFOTL IT8512_MSTCR_FIFOTL_25
93+#define CFG_CR_FREQ IT8512_CFR_CF_36KHZ
94+#define CFG_DCR IT8512_RCR_RXDCR_1
95+#define CFG_BDR IT8512_BDR_6
96+#define CFG_TIMEOUT 100000 /* Rearm interrupt when a space is > 100 ms */
97+
98+static int debug;
99+
100+struct ite8709_device {
101+ int use_count;
102+ int io;
103+ int irq;
104+ spinlock_t hardware_lock;
105+ unsigned long long acc_pulse;
106+ unsigned long long acc_space;
107+ char lastbit;
108+ struct timeval last_tv;
109+ struct lirc_driver driver;
110+ struct tasklet_struct tasklet;
111+ char force_rearm;
112+ char rearmed;
113+ char device_busy;
114+};
115+
116+#define dprintk(fmt, args...) \
117+ do { \
118+ if (debug) \
119+ printk(KERN_DEBUG LIRC_DRIVER_NAME ": " \
120+ fmt, ## args); \
121+ } while (0)
122+
123+
124+static unsigned char ite8709_read(struct ite8709_device *dev,
125+ unsigned char port)
126+{
127+ outb(port, dev->io);
128+ return inb(dev->io+1);
129+}
130+
131+static void ite8709_write(struct ite8709_device *dev, unsigned char port,
132+ unsigned char data)
133+{
134+ outb(port, dev->io);
135+ outb(data, dev->io+1);
136+}
137+
138+static void ite8709_wait_device(struct ite8709_device *dev)
139+{
140+ int i = 0;
141+ /*
142+ * loop until device tells it's ready to continue
143+ * iterations count is usually ~750 but can sometimes achieve 13000
144+ */
145+ for (i = 0; i < 15000; i++) {
146+ udelay(2);
147+ if (ite8709_read(dev, ITE8709_MODE) == ITE8709_MODE_READY)
148+ break;
149+ }
150+}
151+
152+static void ite8709_write_register(struct ite8709_device *dev,
153+ unsigned char reg_adr, unsigned char reg_value)
154+{
155+ ite8709_wait_device(dev);
156+
157+ ite8709_write(dev, ITE8709_REG_VAL, reg_value);
158+ ite8709_write(dev, ITE8709_REG_ADR, reg_adr);
159+ ite8709_write(dev, ITE8709_MODE, ITE8709_MODE_WRITE);
160+}
161+
162+static void ite8709_init_hardware(struct ite8709_device *dev)
163+{
164+ spin_lock_irq(&dev->hardware_lock);
165+ dev->device_busy = 1;
166+ spin_unlock_irq(&dev->hardware_lock);
167+
168+ ite8709_write_register(dev, IT8512_REG_BDHR, (CFG_BDR >> 8) & 0xff);
169+ ite8709_write_register(dev, IT8512_REG_BDLR, CFG_BDR & 0xff);
170+ ite8709_write_register(dev, IT8512_REG_CFR, CFG_CR_FREQ);
171+ ite8709_write_register(dev, IT8512_REG_IER,
172+ IT8512_IER_IEC | IT8512_IER_RFOIE | IT8512_IER_RDAIE);
173+ ite8709_write_register(dev, IT8512_REG_RCR, CFG_DCR);
174+ ite8709_write_register(dev, IT8512_REG_MSTCR,
175+ CFG_FIFOTL | IT8512_MSTCR_FIFOCLR);
176+ ite8709_write_register(dev, IT8512_REG_RCR,
177+ IT8512_RCR_RXEN | IT8512_RCR_RXACT | CFG_DCR);
178+
179+ spin_lock_irq(&dev->hardware_lock);
180+ dev->device_busy = 0;
181+ spin_unlock_irq(&dev->hardware_lock);
182+
183+ tasklet_enable(&dev->tasklet);
184+}
185+
186+static void ite8709_drop_hardware(struct ite8709_device *dev)
187+{
188+ tasklet_disable(&dev->tasklet);
189+
190+ spin_lock_irq(&dev->hardware_lock);
191+ dev->device_busy = 1;
192+ spin_unlock_irq(&dev->hardware_lock);
193+
194+ ite8709_write_register(dev, IT8512_REG_RCR, 0);
195+ ite8709_write_register(dev, IT8512_REG_MSTCR,
196+ IT8512_MSTCR_RESET | IT8512_MSTCR_FIFOCLR);
197+
198+ spin_lock_irq(&dev->hardware_lock);
199+ dev->device_busy = 0;
200+ spin_unlock_irq(&dev->hardware_lock);
201+}
202+
203+static int ite8709_set_use_inc(void *data)
204+{
205+ struct ite8709_device *dev;
206+ dev = data;
207+ if (dev->use_count == 0)
208+ ite8709_init_hardware(dev);
209+ dev->use_count++;
210+ return 0;
211+}
212+
213+static void ite8709_set_use_dec(void *data)
214+{
215+ struct ite8709_device *dev;
216+ dev = data;
217+ dev->use_count--;
218+ if (dev->use_count == 0)
219+ ite8709_drop_hardware(dev);
220+}
221+
222+static void ite8709_add_read_queue(struct ite8709_device *dev, int flag,
223+ unsigned long long val)
224+{
225+ int value;
226+
227+ dprintk("add a %llu usec %s\n", val, flag ? "pulse" : "space");
228+
229+ value = (val > PULSE_MASK) ? PULSE_MASK : val;
230+ if (flag)
231+ value |= PULSE_BIT;
232+
233+ if (!lirc_buffer_full(dev->driver.rbuf)) {
234+ lirc_buffer_write(dev->driver.rbuf, (void *) &value);
235+ wake_up(&dev->driver.rbuf->wait_poll);
236+ }
237+}
238+
239+static irqreturn_t ite8709_interrupt(int irq, void *dev_id)
240+{
241+ unsigned char data;
242+ int iir, rfsr, i;
243+ int fifo = 0;
244+ char bit;
245+ struct timeval curr_tv;
246+
247+ /* Bit duration in microseconds */
248+ const unsigned long bit_duration = 1000000ul / (115200 / CFG_BDR);
249+
250+ struct ite8709_device *dev;
251+ dev = dev_id;
252+
253+ /*
254+ * If device is busy, we simply discard data because we are in one of
255+ * these two cases : shutting down or rearming the device, so this
256+ * doesn't really matter and this avoids waiting too long in IRQ ctx
257+ */
258+ spin_lock(&dev->hardware_lock);
259+ if (dev->device_busy) {
260+ spin_unlock(&dev->hardware_lock);
261+ return IRQ_RETVAL(IRQ_HANDLED);
262+ }
263+
264+ iir = ite8709_read(dev, ITE8709_IIR);
265+
266+ switch (iir) {
267+ case ITE8709_IIR_RFOI:
268+ dprintk("fifo overrun, scheduling forced rearm just in case\n");
269+ dev->force_rearm = 1;
270+ tasklet_schedule(&dev->tasklet);
271+ spin_unlock(&dev->hardware_lock);
272+ return IRQ_RETVAL(IRQ_HANDLED);
273+
274+ case ITE8709_IIR_RDAI:
275+ rfsr = ite8709_read(dev, ITE8709_RFSR);
276+ fifo = rfsr & ITE8709_RFSR_MASK;
277+ if (fifo > 32)
278+ fifo = 32;
279+ dprintk("iir: 0x%x rfsr: 0x%x fifo: %d\n", iir, rfsr, fifo);
280+
281+ if (dev->rearmed) {
282+ do_gettimeofday(&curr_tv);
283+ dev->acc_space += 1000000ull
284+ * (curr_tv.tv_sec - dev->last_tv.tv_sec)
285+ + (curr_tv.tv_usec - dev->last_tv.tv_usec);
286+ dev->rearmed = 0;
287+ }
288+ for (i = 0; i < fifo; i++) {
289+ data = ite8709_read(dev, i+ITE8709_FIFO_START);
290+ data = ~data;
291+ /* Loop through */
292+ for (bit = 0; bit < 8; ++bit) {
293+ if ((data >> bit) & 1) {
294+ dev->acc_pulse += bit_duration;
295+ if (dev->lastbit == 0) {
296+ ite8709_add_read_queue(dev, 0,
297+ dev->acc_space);
298+ dev->acc_space = 0;
299+ }
300+ } else {
301+ dev->acc_space += bit_duration;
302+ if (dev->lastbit == 1) {
303+ ite8709_add_read_queue(dev, 1,
304+ dev->acc_pulse);
305+ dev->acc_pulse = 0;
306+ }
307+ }
308+ dev->lastbit = (data >> bit) & 1;
309+ }
310+ }
311+ ite8709_write(dev, ITE8709_RFSR, 0);
312+
313+ if (dev->acc_space > CFG_TIMEOUT) {
314+ dprintk("scheduling rearm IRQ\n");
315+ do_gettimeofday(&dev->last_tv);
316+ dev->force_rearm = 0;
317+ tasklet_schedule(&dev->tasklet);
318+ }
319+
320+ spin_unlock(&dev->hardware_lock);
321+ return IRQ_RETVAL(IRQ_HANDLED);
322+
323+ default:
324+ /* not our irq */
325+ dprintk("unknown IRQ (shouldn't happen) !!\n");
326+ spin_unlock(&dev->hardware_lock);
327+ return IRQ_RETVAL(IRQ_NONE);
328+ }
329+}
330+
331+static void ite8709_rearm_irq(unsigned long data)
332+{
333+ struct ite8709_device *dev;
334+ unsigned long flags;
335+ dev = (struct ite8709_device *) data;
336+
337+ spin_lock_irqsave(&dev->hardware_lock, flags);
338+ dev->device_busy = 1;
339+ spin_unlock_irqrestore(&dev->hardware_lock, flags);
340+
341+ if (dev->force_rearm || dev->acc_space > CFG_TIMEOUT) {
342+ dprintk("rearming IRQ\n");
343+ ite8709_write_register(dev, IT8512_REG_RCR,
344+ IT8512_RCR_RXACT | CFG_DCR);
345+ ite8709_write_register(dev, IT8512_REG_MSTCR,
346+ CFG_FIFOTL | IT8512_MSTCR_FIFOCLR);
347+ ite8709_write_register(dev, IT8512_REG_RCR,
348+ IT8512_RCR_RXEN | IT8512_RCR_RXACT | CFG_DCR);
349+ if (!dev->force_rearm)
350+ dev->rearmed = 1;
351+ dev->force_rearm = 0;
352+ }
353+
354+ spin_lock_irqsave(&dev->hardware_lock, flags);
355+ dev->device_busy = 0;
356+ spin_unlock_irqrestore(&dev->hardware_lock, flags);
357+}
358+
359+static int ite8709_cleanup(struct ite8709_device *dev, int stage, int errno,
360+ char *msg)
361+{
362+ if (msg != NULL)
363+ printk(KERN_ERR LIRC_DRIVER_NAME ": %s\n", msg);
364+
365+ switch (stage) {
366+ case 6:
367+ if (dev->use_count > 0)
368+ ite8709_drop_hardware(dev);
369+ case 5:
370+ free_irq(dev->irq, dev);
371+ case 4:
372+ release_region(dev->io, 2);
373+ case 3:
374+ lirc_unregister_driver(dev->driver.minor);
375+ case 2:
376+ lirc_buffer_free(dev->driver.rbuf);
377+ kfree(dev->driver.rbuf);
378+ case 1:
379+ kfree(dev);
380+ case 0:
381+ ;
382+ }
383+
384+ return errno;
385+}
386+
387+static int __devinit ite8709_pnp_probe(struct pnp_dev *dev,
388+ const struct pnp_device_id *dev_id)
389+{
390+ struct lirc_driver *driver;
391+ struct ite8709_device *ite8709_dev;
392+ int ret;
393+
394+ /* Check resources validity */
395+ if (!pnp_irq_valid(dev, 0))
396+ return ite8709_cleanup(NULL, 0, -ENODEV, "invalid IRQ");
397+ if (!pnp_port_valid(dev, 2))
398+ return ite8709_cleanup(NULL, 0, -ENODEV, "invalid IO port");
399+
400+ /* Allocate memory for device struct */
401+ ite8709_dev = kzalloc(sizeof(struct ite8709_device), GFP_KERNEL);
402+ if (ite8709_dev == NULL)
403+ return ite8709_cleanup(NULL, 0, -ENOMEM, "kzalloc failed");
404+ pnp_set_drvdata(dev, ite8709_dev);
405+
406+ /* Initialize device struct */
407+ ite8709_dev->use_count = 0;
408+ ite8709_dev->irq = pnp_irq(dev, 0);
409+ ite8709_dev->io = pnp_port_start(dev, 2);
410+ ite8709_dev->hardware_lock =
411+ __SPIN_LOCK_UNLOCKED(ite8709_dev->hardware_lock);
412+ ite8709_dev->acc_pulse = 0;
413+ ite8709_dev->acc_space = 0;
414+ ite8709_dev->lastbit = 0;
415+ do_gettimeofday(&ite8709_dev->last_tv);
416+ tasklet_init(&ite8709_dev->tasklet, ite8709_rearm_irq,
417+ (long) ite8709_dev);
418+ ite8709_dev->force_rearm = 0;
419+ ite8709_dev->rearmed = 0;
420+ ite8709_dev->device_busy = 0;
421+
422+ /* Initialize driver struct */
423+ driver = &ite8709_dev->driver;
424+ strcpy(driver->name, LIRC_DRIVER_NAME);
425+ driver->minor = -1;
426+ driver->code_length = sizeof(int) * 8;
427+ driver->sample_rate = 0;
428+ driver->features = LIRC_CAN_REC_MODE2;
429+ driver->data = ite8709_dev;
430+ driver->add_to_buf = NULL;
431+ driver->set_use_inc = ite8709_set_use_inc;
432+ driver->set_use_dec = ite8709_set_use_dec;
433+ driver->dev = &dev->dev;
434+ driver->owner = THIS_MODULE;
435+
436+ /* Initialize LIRC buffer */
437+ driver->rbuf = kmalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
438+ if (!driver->rbuf)
439+ return ite8709_cleanup(ite8709_dev, 1, -ENOMEM,
440+ "can't allocate lirc_buffer");
441+ if (lirc_buffer_init(driver->rbuf, BUF_CHUNK_SIZE, BUF_SIZE))
442+ return ite8709_cleanup(ite8709_dev, 1, -ENOMEM,
443+ "lirc_buffer_init() failed");
444+
445+ /* Register LIRC driver */
446+ ret = lirc_register_driver(driver);
447+ if (ret < 0)
448+ return ite8709_cleanup(ite8709_dev, 2, ret,
449+ "lirc_register_driver() failed");
450+
451+ /* Reserve I/O port access */
452+ if (!request_region(ite8709_dev->io, 2, LIRC_DRIVER_NAME))
453+ return ite8709_cleanup(ite8709_dev, 3, -EBUSY,
454+ "i/o port already in use");
455+
456+ /* Reserve IRQ line */
457+ ret = request_irq(ite8709_dev->irq, ite8709_interrupt, 0,
458+ LIRC_DRIVER_NAME, ite8709_dev);
459+ if (ret < 0)
460+ return ite8709_cleanup(ite8709_dev, 4, ret,
461+ "IRQ already in use");
462+
463+ /* Initialize hardware */
464+ ite8709_drop_hardware(ite8709_dev); /* Shutdown hw until first use */
465+
466+ printk(KERN_INFO LIRC_DRIVER_NAME ": device found : irq=%d io=0x%x\n",
467+ ite8709_dev->irq, ite8709_dev->io);
468+
469+ return 0;
470+}
471+
472+static void __devexit ite8709_pnp_remove(struct pnp_dev *dev)
473+{
474+ struct ite8709_device *ite8709_dev;
475+ ite8709_dev = pnp_get_drvdata(dev);
476+
477+ ite8709_cleanup(ite8709_dev, 6, 0, NULL);
478+
479+ printk(KERN_INFO LIRC_DRIVER_NAME ": device removed\n");
480+}
481+
482+#ifdef CONFIG_PM
483+static int ite8709_pnp_suspend(struct pnp_dev *dev, pm_message_t state)
484+{
485+ struct ite8709_device *ite8709_dev;
486+ ite8709_dev = pnp_get_drvdata(dev);
487+
488+ if (ite8709_dev->use_count > 0)
489+ ite8709_drop_hardware(ite8709_dev);
490+
491+ return 0;
492+}
493+
494+static int ite8709_pnp_resume(struct pnp_dev *dev)
495+{
496+ struct ite8709_device *ite8709_dev;
497+ ite8709_dev = pnp_get_drvdata(dev);
498+
499+ if (ite8709_dev->use_count > 0)
500+ ite8709_init_hardware(ite8709_dev);
501+
502+ return 0;
503+}
504+#else
505+#define ite8709_pnp_suspend NULL
506+#define ite8709_pnp_resume NULL
507+#endif
508+
509+static const struct pnp_device_id pnp_dev_table[] = {
510+ {"ITE8709", 0},
511+ {}
512+};
513+
514+MODULE_DEVICE_TABLE(pnp, pnp_dev_table);
515+
516+static struct pnp_driver ite8709_pnp_driver = {
517+ .name = LIRC_DRIVER_NAME,
518+ .probe = ite8709_pnp_probe,
519+ .remove = __devexit_p(ite8709_pnp_remove),
520+ .suspend = ite8709_pnp_suspend,
521+ .resume = ite8709_pnp_resume,
522+ .id_table = pnp_dev_table,
523+};
524+
525+static int __init ite8709_init_module(void)
526+{
527+ return pnp_register_driver(&ite8709_pnp_driver);
528+}
529+module_init(ite8709_init_module);
530+
531+static void __exit ite8709_cleanup_module(void)
532+{
533+ pnp_unregister_driver(&ite8709_pnp_driver);
534+}
535+module_exit(ite8709_cleanup_module);
536+
537+MODULE_DESCRIPTION("LIRC driver for ITE8709 CIR port");
538+MODULE_AUTHOR("Grégory Lardière");
539+MODULE_LICENSE("GPL");
540+
541+module_param(debug, bool, S_IRUGO | S_IWUSR);
542+MODULE_PARM_DESC(debug, "Enable debugging messages");