drivers/media/rc/ir-rx51.c

   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 #include <linux/clk.h>
  17 #include <linux/module.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/wait.h>
  20 #include <linux/pwm.h>
  21 #include <linux/of.h>
  22 #include <linux/hrtimer.h>
  23
  24 #include <media/rc-core.h>
  25 #include <linux/platform_data/media/ir-rx51.h>
  26
  27 #define WBUF_LEN 256
  28
  29 struct ir_rx51 {
  30         struct rc_dev *rcdev;
  31         struct pwm_device *pwm;
  32         struct hrtimer timer;
  33         struct device        *dev;
  34         struct ir_rx51_platform_data *pdata;
  35         wait_queue_head_t     wqueue;
  36
  37         unsigned int    freq;           /* carrier frequency */
  38         unsigned int    duty_cycle;     /* carrier duty cycle */
  39         int             wbuf[WBUF_LEN];
  40         int             wbuf_index;
  41         unsigned long   device_is_open;
  42 };
  43
  44 static inline void ir_rx51_on(struct ir_rx51 *ir_rx51)
  45 {
  46         pwm_enable(ir_rx51->pwm);
  47 }
  48
  49 static inline void ir_rx51_off(struct ir_rx51 *ir_rx51)
  50 {
  51         pwm_disable(ir_rx51->pwm);
  52 }
  53
  54 static int init_timing_params(struct ir_rx51 *ir_rx51)
  55 {
  56         struct pwm_device *pwm = ir_rx51->pwm;
  57         int duty, period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, ir_rx51->freq);
  58
  59         duty = DIV_ROUND_CLOSEST(ir_rx51->duty_cycle * period, 100);
  60
  61         pwm_config(pwm, duty, period);
  62
  63         return 0;
  64 }
  65
  66 static enum hrtimer_restart ir_rx51_timer_cb(struct hrtimer *timer)
  67 {
  68         struct ir_rx51 *ir_rx51 = container_of(timer, struct ir_rx51, timer);
  69         ktime_t now;
  70
  71         if (ir_rx51->wbuf_index < 0) {
  72                 dev_err_ratelimited(ir_rx51->dev,
  73                                     "BUG wbuf_index has value of %i\n",
  74                                     ir_rx51->wbuf_index);
  75                 goto end;
  76         }
  77
  78         /*
  79          * If we happen to hit an odd latency spike, loop through the
  80          * pulses until we catch up.
  81          */
  82         do {
  83                 u64 ns;
  84
  85                 if (ir_rx51->wbuf_index >= WBUF_LEN)
  86                         goto end;
  87                 if (ir_rx51->wbuf[ir_rx51->wbuf_index] == -1)
  88                         goto end;
  89
  90                 if (ir_rx51->wbuf_index % 2)
  91                         ir_rx51_off(ir_rx51);
  92                 else
  93                         ir_rx51_on(ir_rx51);
  94
  95                 ns = US_TO_NS(ir_rx51->wbuf[ir_rx51->wbuf_index]);
  96                 hrtimer_add_expires_ns(timer, ns);
  97
  98                 ir_rx51->wbuf_index++;
  99
 100                 now = timer->base->get_time();
 101
 102         } while (hrtimer_get_expires_tv64(timer) < now);
 103
 104         return HRTIMER_RESTART;
 105 end:
 106         /* Stop TX here */
 107         ir_rx51_off(ir_rx51);
 108         ir_rx51->wbuf_index = -1;
 109
 110         wake_up_interruptible(&ir_rx51->wqueue);
 111
 112         return HRTIMER_NORESTART;
 113 }
 114
 115 static int ir_rx51_tx(struct rc_dev *dev, unsigned int *buffer,
 116                       unsigned int count)
 117 {
 118         struct ir_rx51 *ir_rx51 = dev->priv;
 119
 120         if (count > WBUF_LEN)
 121                 return -EINVAL;
 122
 123         memcpy(ir_rx51->wbuf, buffer, count * sizeof(unsigned int));
 124
 125         /* Wait any pending transfers to finish */
 126         wait_event_interruptible(ir_rx51->wqueue, ir_rx51->wbuf_index < 0);
 127
 128         init_timing_params(ir_rx51);
 129         if (count < WBUF_LEN)
 130                 ir_rx51->wbuf[count] = -1; /* Insert termination mark */
 131
 132         /*
 133          * Adjust latency requirements so the device doesn't go in too
 134          * deep sleep states
 135          */
 136         ir_rx51->pdata->set_max_mpu_wakeup_lat(ir_rx51->dev, 50);
 137
 138         ir_rx51_on(ir_rx51);
 139         ir_rx51->wbuf_index = 1;
 140         hrtimer_start(&ir_rx51->timer,
 141                       ns_to_ktime(US_TO_NS(ir_rx51->wbuf[0])),
 142                       HRTIMER_MODE_REL);
 143         /*
 144          * Don't return back to the userspace until the transfer has
 145          * finished
 146          */
 147         wait_event_interruptible(ir_rx51->wqueue, ir_rx51->wbuf_index < 0);
 148
 149         /* We can sleep again */
 150         ir_rx51->pdata->set_max_mpu_wakeup_lat(ir_rx51->dev, -1);
 151
 152         return count;
 153 }
 154
 155 static int ir_rx51_open(struct rc_dev *dev)
 156 {
 157         struct ir_rx51 *ir_rx51 = dev->priv;
 158
 159         if (test_and_set_bit(1, &ir_rx51->device_is_open))
 160                 return -EBUSY;
 161
 162         ir_rx51->pwm = pwm_get(ir_rx51->dev, NULL);
 163         if (IS_ERR(ir_rx51->pwm)) {
 164                 int res = PTR_ERR(ir_rx51->pwm);
 165
 166                 dev_err(ir_rx51->dev, "pwm_get failed: %d\n", res);
 167                 return res;
 168         }
 169
 170         return 0;
 171 }
 172
 173 static void ir_rx51_release(struct rc_dev *dev)
 174 {
 175         struct ir_rx51 *ir_rx51 = dev->priv;
 176
 177         hrtimer_cancel(&ir_rx51->timer);
 178         ir_rx51_off(ir_rx51);
 179         pwm_put(ir_rx51->pwm);
 180
 181         clear_bit(1, &ir_rx51->device_is_open);
 182 }
 183
 184 static struct ir_rx51 ir_rx51 = {
 185         .duty_cycle     = 50,
 186         .wbuf_index     = -1,
 187 };
 188
 189 static int ir_rx51_set_duty_cycle(struct rc_dev *dev, u32 duty)
 190 {
 191         struct ir_rx51 *ir_rx51 = dev->priv;
 192
 193         ir_rx51->duty_cycle = duty;
 194
 195         return 0;
 196 }
 197
 198 static int ir_rx51_set_tx_carrier(struct rc_dev *dev, u32 carrier)
 199 {
 200         struct ir_rx51 *ir_rx51 = dev->priv;
 201
 202         if (carrier > 500000 || carrier < 20000)
 203                 return -EINVAL;
 204
 205         ir_rx51->freq = carrier;
 206
 207         return 0;
 208 }
 209
 210 #ifdef CONFIG_PM
 211
 212 static int ir_rx51_suspend(struct platform_device *dev, pm_message_t state)
 213 {
 214         /*
 215          * In case the device is still open, do not suspend. Normally
 216          * this should not be a problem as lircd only keeps the device
 217          * open only for short periods of time. We also don't want to
 218          * get involved with race conditions that might happen if we
 219          * were in a middle of a transmit. Thus, we defer any suspend
 220          * actions until transmit has completed.
 221          */
 222         if (test_and_set_bit(1, &ir_rx51.device_is_open))
 223                 return -EAGAIN;
 224
 225         clear_bit(1, &ir_rx51.device_is_open);
 226
 227         return 0;
 228 }
 229
 230 static int ir_rx51_resume(struct platform_device *dev)
 231 {
 232         return 0;
 233 }
 234
 235 #else
 236
 237 #define ir_rx51_suspend NULL
 238 #define ir_rx51_resume  NULL
 239
 240 #endif /* CONFIG_PM */
 241
 242 static int ir_rx51_probe(struct platform_device *dev)
 243 {
 244         struct pwm_device *pwm;
 245         struct rc_dev *rcdev;
 246
 247         ir_rx51.pdata = dev->dev.platform_data;
 248
 249         if (!ir_rx51.pdata) {
 250                 dev_err(&dev->dev, "Platform Data is missing\n");
 251                 return -ENXIO;
 252         }
 253
 254         pwm = pwm_get(&dev->dev, NULL);
 255         if (IS_ERR(pwm)) {
 256                 int err = PTR_ERR(pwm);
 257
 258                 if (err != -EPROBE_DEFER)
 259                         dev_err(&dev->dev, "pwm_get failed: %d\n", err);
 260                 return err;
 261         }
 262
 263         /* Use default, in case userspace does not set the carrier */
 264         ir_rx51.freq = DIV_ROUND_CLOSEST(pwm_get_period(pwm), NSEC_PER_SEC);
 265         pwm_put(pwm);
 266
 267         hrtimer_init(&ir_rx51.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 268         ir_rx51.timer.function = ir_rx51_timer_cb;
 269
 270         ir_rx51.dev = &dev->dev;
 271
 272         rcdev = devm_rc_allocate_device(&dev->dev, RC_DRIVER_IR_RAW_TX);
 273         if (!rcdev)
 274                 return -ENOMEM;
 275
 276         rcdev->priv = &ir_rx51;
 277         rcdev->open = ir_rx51_open;
 278         rcdev->close = ir_rx51_release;
 279         rcdev->tx_ir = ir_rx51_tx;
 280         rcdev->s_tx_duty_cycle = ir_rx51_set_duty_cycle;
 281         rcdev->s_tx_carrier = ir_rx51_set_tx_carrier;
 282         rcdev->driver_name = KBUILD_MODNAME;
 283
 284         ir_rx51.rcdev = rcdev;
 285
 286         return devm_rc_register_device(&dev->dev, ir_rx51.rcdev);
 287 }
 288
 289 static int ir_rx51_remove(struct platform_device *dev)
 290 {
 291         return 0;
 292 }
 293
 294 static const struct of_device_id ir_rx51_match[] = {
 295         {
 296                 .compatible = "nokia,n900-ir",
 297         },
 298         {},
 299 };
 300 MODULE_DEVICE_TABLE(of, ir_rx51_match);
 301
 302 static struct platform_driver ir_rx51_platform_driver = {
 303         .probe          = ir_rx51_probe,
 304         .remove         = ir_rx51_remove,
 305         .suspend        = ir_rx51_suspend,
 306         .resume         = ir_rx51_resume,
 307         .driver         = {
 308                 .name   = KBUILD_MODNAME,
 309                 .of_match_table = of_match_ptr(ir_rx51_match),
 310         },
 311 };
 312 module_platform_driver(ir_rx51_platform_driver);
 313
 314 MODULE_DESCRIPTION("IR TX driver for Nokia RX51");
 315 MODULE_AUTHOR("Nokia Corporation");
 316 MODULE_LICENSE("GPL");