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1  /*
2   *  Copyright (C) 2008 Nokia Corporation
3   *
4   *  Based on lirc_serial.c
5   *
6   *  This program is free software; you can redistribute it and/or modify
7   *  it under the terms of the GNU General Public License as published by
8   *  the Free Software Foundation; either version 2 of the License, or
9   *  (at your option) any later version.
10   *
11   *  This program is distributed in the hope that it will be useful,
12   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14   *  GNU 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  USA
19   *
20   */
21  
22  #include <linux/module.h>
23  #include <linux/interrupt.h>
24  #include <linux/uaccess.h>
25  #include <linux/platform_device.h>
26  #include <linux/sched.h>
27  #include <linux/wait.h>
28  
29  #include <plat/dmtimer.h>
30  #include <plat/clock.h>
31  
32  #include <media/lirc.h>
33  #include <media/lirc_dev.h>
34  #include <media/ir-rx51.h>
35  
36  #define LIRC_RX51_DRIVER_FEATURES (LIRC_CAN_SET_SEND_DUTY_CYCLE |	\
37  				   LIRC_CAN_SET_SEND_CARRIER |		\
38  				   LIRC_CAN_SEND_PULSE)
39  
40  #define DRIVER_NAME "lirc_rx51"
41  
42  #define WBUF_LEN 256
43  
44  #define TIMER_MAX_VALUE 0xffffffff
45  
46  struct lirc_rx51 {
47  	struct omap_dm_timer *pwm_timer;
48  	struct omap_dm_timer *pulse_timer;
49  	struct device	     *dev;
50  	struct lirc_rx51_platform_data *pdata;
51  	wait_queue_head_t     wqueue;
52  
53  	unsigned long	fclk_khz;
54  	unsigned int	freq;		/* carrier frequency */
55  	unsigned int	duty_cycle;	/* carrier duty cycle */
56  	unsigned int	irq_num;
57  	unsigned int	match;
58  	int		wbuf[WBUF_LEN];
59  	int		wbuf_index;
60  	unsigned long	device_is_open;
61  	int		pwm_timer_num;
62  };
63  
lirc_rx51_on(struct lirc_rx51 * lirc_rx51)64  static void lirc_rx51_on(struct lirc_rx51 *lirc_rx51)
65  {
66  	omap_dm_timer_set_pwm(lirc_rx51->pwm_timer, 0, 1,
67  			      OMAP_TIMER_TRIGGER_OVERFLOW_AND_COMPARE);
68  }
69  
lirc_rx51_off(struct lirc_rx51 * lirc_rx51)70  static void lirc_rx51_off(struct lirc_rx51 *lirc_rx51)
71  {
72  	omap_dm_timer_set_pwm(lirc_rx51->pwm_timer, 0, 1,
73  			      OMAP_TIMER_TRIGGER_NONE);
74  }
75  
init_timing_params(struct lirc_rx51 * lirc_rx51)76  static int init_timing_params(struct lirc_rx51 *lirc_rx51)
77  {
78  	u32 load, match;
79  
80  	load = -(lirc_rx51->fclk_khz * 1000 / lirc_rx51->freq);
81  	match = -(lirc_rx51->duty_cycle * -load / 100);
82  	omap_dm_timer_set_load(lirc_rx51->pwm_timer, 1, load);
83  	omap_dm_timer_set_match(lirc_rx51->pwm_timer, 1, match);
84  	omap_dm_timer_write_counter(lirc_rx51->pwm_timer, TIMER_MAX_VALUE - 2);
85  	omap_dm_timer_start(lirc_rx51->pwm_timer);
86  	omap_dm_timer_set_int_enable(lirc_rx51->pulse_timer, 0);
87  	omap_dm_timer_start(lirc_rx51->pulse_timer);
88  
89  	lirc_rx51->match = 0;
90  
91  	return 0;
92  }
93  
94  #define tics_after(a, b) ((long)(b) - (long)(a) < 0)
95  
pulse_timer_set_timeout(struct lirc_rx51 * lirc_rx51,int usec)96  static int pulse_timer_set_timeout(struct lirc_rx51 *lirc_rx51, int usec)
97  {
98  	int counter;
99  
100  	BUG_ON(usec < 0);
101  
102  	if (lirc_rx51->match == 0)
103  		counter = omap_dm_timer_read_counter(lirc_rx51->pulse_timer);
104  	else
105  		counter = lirc_rx51->match;
106  
107  	counter += (u32)(lirc_rx51->fclk_khz * usec / (1000));
108  	omap_dm_timer_set_match(lirc_rx51->pulse_timer, 1, counter);
109  	omap_dm_timer_set_int_enable(lirc_rx51->pulse_timer,
110  				     OMAP_TIMER_INT_MATCH);
111  	if (tics_after(omap_dm_timer_read_counter(lirc_rx51->pulse_timer),
112  		       counter)) {
113  		return 1;
114  	}
115  	return 0;
116  }
117  
lirc_rx51_interrupt_handler(int irq,void * ptr)118  static irqreturn_t lirc_rx51_interrupt_handler(int irq, void *ptr)
119  {
120  	unsigned int retval;
121  	struct lirc_rx51 *lirc_rx51 = ptr;
122  
123  	retval = omap_dm_timer_read_status(lirc_rx51->pulse_timer);
124  	if (!retval)
125  		return IRQ_NONE;
126  
127  	if (retval & ~OMAP_TIMER_INT_MATCH)
128  		dev_err_ratelimited(lirc_rx51->dev,
129  				": Unexpected interrupt source: %x\n", retval);
130  
131  	omap_dm_timer_write_status(lirc_rx51->pulse_timer,
132  				OMAP_TIMER_INT_MATCH	|
133  				OMAP_TIMER_INT_OVERFLOW	|
134  				OMAP_TIMER_INT_CAPTURE);
135  	if (lirc_rx51->wbuf_index < 0) {
136  		dev_err_ratelimited(lirc_rx51->dev,
137  				": BUG wbuf_index has value of %i\n",
138  				lirc_rx51->wbuf_index);
139  		goto end;
140  	}
141  
142  	/*
143  	 * If we happen to hit an odd latency spike, loop through the
144  	 * pulses until we catch up.
145  	 */
146  	do {
147  		if (lirc_rx51->wbuf_index >= WBUF_LEN)
148  			goto end;
149  		if (lirc_rx51->wbuf[lirc_rx51->wbuf_index] == -1)
150  			goto end;
151  
152  		if (lirc_rx51->wbuf_index % 2)
153  			lirc_rx51_off(lirc_rx51);
154  		else
155  			lirc_rx51_on(lirc_rx51);
156  
157  		retval = pulse_timer_set_timeout(lirc_rx51,
158  					lirc_rx51->wbuf[lirc_rx51->wbuf_index]);
159  		lirc_rx51->wbuf_index++;
160  
161  	} while (retval);
162  
163  	return IRQ_HANDLED;
164  end:
165  	/* Stop TX here */
166  	lirc_rx51_off(lirc_rx51);
167  	lirc_rx51->wbuf_index = -1;
168  	omap_dm_timer_stop(lirc_rx51->pwm_timer);
169  	omap_dm_timer_stop(lirc_rx51->pulse_timer);
170  	omap_dm_timer_set_int_enable(lirc_rx51->pulse_timer, 0);
171  	wake_up_interruptible(&lirc_rx51->wqueue);
172  
173  	return IRQ_HANDLED;
174  }
175  
lirc_rx51_init_port(struct lirc_rx51 * lirc_rx51)176  static int lirc_rx51_init_port(struct lirc_rx51 *lirc_rx51)
177  {
178  	struct clk *clk_fclk;
179  	int retval, pwm_timer = lirc_rx51->pwm_timer_num;
180  
181  	lirc_rx51->pwm_timer = omap_dm_timer_request_specific(pwm_timer);
182  	if (lirc_rx51->pwm_timer == NULL) {
183  		dev_err(lirc_rx51->dev, ": Error requesting GPT%d timer\n",
184  			pwm_timer);
185  		return -EBUSY;
186  	}
187  
188  	lirc_rx51->pulse_timer = omap_dm_timer_request();
189  	if (lirc_rx51->pulse_timer == NULL) {
190  		dev_err(lirc_rx51->dev, ": Error requesting pulse timer\n");
191  		retval = -EBUSY;
192  		goto err1;
193  	}
194  
195  	omap_dm_timer_set_source(lirc_rx51->pwm_timer, OMAP_TIMER_SRC_SYS_CLK);
196  	omap_dm_timer_set_source(lirc_rx51->pulse_timer,
197  				OMAP_TIMER_SRC_SYS_CLK);
198  
199  	omap_dm_timer_enable(lirc_rx51->pwm_timer);
200  	omap_dm_timer_enable(lirc_rx51->pulse_timer);
201  
202  	lirc_rx51->irq_num = omap_dm_timer_get_irq(lirc_rx51->pulse_timer);
203  	retval = request_irq(lirc_rx51->irq_num, lirc_rx51_interrupt_handler,
204  			     IRQF_SHARED, "lirc_pulse_timer", lirc_rx51);
205  	if (retval) {
206  		dev_err(lirc_rx51->dev, ": Failed to request interrupt line\n");
207  		goto err2;
208  	}
209  
210  	clk_fclk = omap_dm_timer_get_fclk(lirc_rx51->pwm_timer);
211  	lirc_rx51->fclk_khz = clk_fclk->rate / 1000;
212  
213  	return 0;
214  
215  err2:
216  	omap_dm_timer_free(lirc_rx51->pulse_timer);
217  err1:
218  	omap_dm_timer_free(lirc_rx51->pwm_timer);
219  
220  	return retval;
221  }
222  
lirc_rx51_free_port(struct lirc_rx51 * lirc_rx51)223  static int lirc_rx51_free_port(struct lirc_rx51 *lirc_rx51)
224  {
225  	omap_dm_timer_set_int_enable(lirc_rx51->pulse_timer, 0);
226  	free_irq(lirc_rx51->irq_num, lirc_rx51);
227  	lirc_rx51_off(lirc_rx51);
228  	omap_dm_timer_disable(lirc_rx51->pwm_timer);
229  	omap_dm_timer_disable(lirc_rx51->pulse_timer);
230  	omap_dm_timer_free(lirc_rx51->pwm_timer);
231  	omap_dm_timer_free(lirc_rx51->pulse_timer);
232  	lirc_rx51->wbuf_index = -1;
233  
234  	return 0;
235  }
236  
lirc_rx51_write(struct file * file,const char * buf,size_t n,loff_t * ppos)237  static ssize_t lirc_rx51_write(struct file *file, const char *buf,
238  			  size_t n, loff_t *ppos)
239  {
240  	int count, i;
241  	struct lirc_rx51 *lirc_rx51 = file->private_data;
242  
243  	if (n % sizeof(int))
244  		return -EINVAL;
245  
246  	count = n / sizeof(int);
247  	if ((count > WBUF_LEN) || (count % 2 == 0))
248  		return -EINVAL;
249  
250  	/* Wait any pending transfers to finish */
251  	wait_event_interruptible(lirc_rx51->wqueue, lirc_rx51->wbuf_index < 0);
252  
253  	if (copy_from_user(lirc_rx51->wbuf, buf, n))
254  		return -EFAULT;
255  
256  	/* Sanity check the input pulses */
257  	for (i = 0; i < count; i++)
258  		if (lirc_rx51->wbuf[i] < 0)
259  			return -EINVAL;
260  
261  	init_timing_params(lirc_rx51);
262  	if (count < WBUF_LEN)
263  		lirc_rx51->wbuf[count] = -1; /* Insert termination mark */
264  
265  	/*
266  	 * Adjust latency requirements so the device doesn't go in too
267  	 * deep sleep states
268  	 */
269  	lirc_rx51->pdata->set_max_mpu_wakeup_lat(lirc_rx51->dev, 50);
270  
271  	lirc_rx51_on(lirc_rx51);
272  	lirc_rx51->wbuf_index = 1;
273  	pulse_timer_set_timeout(lirc_rx51, lirc_rx51->wbuf[0]);
274  
275  	/*
276  	 * Don't return back to the userspace until the transfer has
277  	 * finished
278  	 */
279  	wait_event_interruptible(lirc_rx51->wqueue, lirc_rx51->wbuf_index < 0);
280  
281  	/* We can sleep again */
282  	lirc_rx51->pdata->set_max_mpu_wakeup_lat(lirc_rx51->dev, -1);
283  
284  	return n;
285  }
286  
lirc_rx51_ioctl(struct file * filep,unsigned int cmd,unsigned long arg)287  static long lirc_rx51_ioctl(struct file *filep,
288  			unsigned int cmd, unsigned long arg)
289  {
290  	int result;
291  	unsigned long value;
292  	unsigned int ivalue;
293  	struct lirc_rx51 *lirc_rx51 = filep->private_data;
294  
295  	switch (cmd) {
296  	case LIRC_GET_SEND_MODE:
297  		result = put_user(LIRC_MODE_PULSE, (unsigned long *)arg);
298  		if (result)
299  			return result;
300  		break;
301  
302  	case LIRC_SET_SEND_MODE:
303  		result = get_user(value, (unsigned long *)arg);
304  		if (result)
305  			return result;
306  
307  		/* only LIRC_MODE_PULSE supported */
308  		if (value != LIRC_MODE_PULSE)
309  			return -ENOSYS;
310  		break;
311  
312  	case LIRC_GET_REC_MODE:
313  		result = put_user(0, (unsigned long *) arg);
314  		if (result)
315  			return result;
316  		break;
317  
318  	case LIRC_GET_LENGTH:
319  		return -ENOSYS;
320  		break;
321  
322  	case LIRC_SET_SEND_DUTY_CYCLE:
323  		result = get_user(ivalue, (unsigned int *) arg);
324  		if (result)
325  			return result;
326  
327  		if (ivalue <= 0 || ivalue > 100) {
328  			dev_err(lirc_rx51->dev, ": invalid duty cycle %d\n",
329  				ivalue);
330  			return -EINVAL;
331  		}
332  
333  		lirc_rx51->duty_cycle = ivalue;
334  		break;
335  
336  	case LIRC_SET_SEND_CARRIER:
337  		result = get_user(ivalue, (unsigned int *) arg);
338  		if (result)
339  			return result;
340  
341  		if (ivalue > 500000 || ivalue < 20000) {
342  			dev_err(lirc_rx51->dev, ": invalid carrier freq %d\n",
343  				ivalue);
344  			return -EINVAL;
345  		}
346  
347  		lirc_rx51->freq = ivalue;
348  		break;
349  
350  	case LIRC_GET_FEATURES:
351  		result = put_user(LIRC_RX51_DRIVER_FEATURES,
352  				  (unsigned long *) arg);
353  		if (result)
354  			return result;
355  		break;
356  
357  	default:
358  		return -ENOIOCTLCMD;
359  	}
360  
361  	return 0;
362  }
363  
lirc_rx51_open(struct inode * inode,struct file * file)364  static int lirc_rx51_open(struct inode *inode, struct file *file)
365  {
366  	struct lirc_rx51 *lirc_rx51 = lirc_get_pdata(file);
367  	BUG_ON(!lirc_rx51);
368  
369  	file->private_data = lirc_rx51;
370  
371  	if (test_and_set_bit(1, &lirc_rx51->device_is_open))
372  		return -EBUSY;
373  
374  	return lirc_rx51_init_port(lirc_rx51);
375  }
376  
lirc_rx51_release(struct inode * inode,struct file * file)377  static int lirc_rx51_release(struct inode *inode, struct file *file)
378  {
379  	struct lirc_rx51 *lirc_rx51 = file->private_data;
380  
381  	lirc_rx51_free_port(lirc_rx51);
382  
383  	clear_bit(1, &lirc_rx51->device_is_open);
384  
385  	return 0;
386  }
387  
388  static struct lirc_rx51 lirc_rx51 = {
389  	.freq		= 38000,
390  	.duty_cycle	= 50,
391  	.wbuf_index	= -1,
392  };
393  
394  static const struct file_operations lirc_fops = {
395  	.owner		= THIS_MODULE,
396  	.write		= lirc_rx51_write,
397  	.unlocked_ioctl	= lirc_rx51_ioctl,
398  	.read		= lirc_dev_fop_read,
399  	.poll		= lirc_dev_fop_poll,
400  	.open		= lirc_rx51_open,
401  	.release	= lirc_rx51_release,
402  };
403  
404  static struct lirc_driver lirc_rx51_driver = {
405  	.name		= DRIVER_NAME,
406  	.minor		= -1,
407  	.code_length	= 1,
408  	.data		= &lirc_rx51,
409  	.fops		= &lirc_fops,
410  	.owner		= THIS_MODULE,
411  };
412  
413  #ifdef CONFIG_PM
414  
lirc_rx51_suspend(struct platform_device * dev,pm_message_t state)415  static int lirc_rx51_suspend(struct platform_device *dev, pm_message_t state)
416  {
417  	/*
418  	 * In case the device is still open, do not suspend. Normally
419  	 * this should not be a problem as lircd only keeps the device
420  	 * open only for short periods of time. We also don't want to
421  	 * get involved with race conditions that might happen if we
422  	 * were in a middle of a transmit. Thus, we defer any suspend
423  	 * actions until transmit has completed.
424  	 */
425  	if (test_and_set_bit(1, &lirc_rx51.device_is_open))
426  		return -EAGAIN;
427  
428  	clear_bit(1, &lirc_rx51.device_is_open);
429  
430  	return 0;
431  }
432  
lirc_rx51_resume(struct platform_device * dev)433  static int lirc_rx51_resume(struct platform_device *dev)
434  {
435  	return 0;
436  }
437  
438  #else
439  
440  #define lirc_rx51_suspend	NULL
441  #define lirc_rx51_resume	NULL
442  
443  #endif /* CONFIG_PM */
444  
lirc_rx51_probe(struct platform_device * dev)445  static int lirc_rx51_probe(struct platform_device *dev)
446  {
447  	lirc_rx51_driver.features = LIRC_RX51_DRIVER_FEATURES;
448  	lirc_rx51.pdata = dev->dev.platform_data;
449  	lirc_rx51.pwm_timer_num = lirc_rx51.pdata->pwm_timer;
450  	lirc_rx51.dev = &dev->dev;
451  	lirc_rx51_driver.dev = &dev->dev;
452  	lirc_rx51_driver.minor = lirc_register_driver(&lirc_rx51_driver);
453  	init_waitqueue_head(&lirc_rx51.wqueue);
454  
455  	if (lirc_rx51_driver.minor < 0) {
456  		dev_err(lirc_rx51.dev, ": lirc_register_driver failed: %d\n",
457  		       lirc_rx51_driver.minor);
458  		return lirc_rx51_driver.minor;
459  	}
460  	dev_info(lirc_rx51.dev, "registration ok, minor: %d, pwm: %d\n",
461  		 lirc_rx51_driver.minor, lirc_rx51.pwm_timer_num);
462  
463  	return 0;
464  }
465  
lirc_rx51_remove(struct platform_device * dev)466  static int lirc_rx51_remove(struct platform_device *dev)
467  {
468  	return lirc_unregister_driver(lirc_rx51_driver.minor);
469  }
470  
471  struct platform_driver lirc_rx51_platform_driver = {
472  	.probe		= lirc_rx51_probe,
473  	.remove		= lirc_rx51_remove,
474  	.suspend	= lirc_rx51_suspend,
475  	.resume		= lirc_rx51_resume,
476  	.driver		= {
477  		.name	= DRIVER_NAME,
478  		.owner	= THIS_MODULE,
479  	},
480  };
481  module_platform_driver(lirc_rx51_platform_driver);
482  
483  MODULE_DESCRIPTION("LIRC TX driver for Nokia RX51");
484  MODULE_AUTHOR("Nokia Corporation");
485  MODULE_LICENSE("GPL");
486