drivers/staging/iio/trigger/iio-trig-bfin-timer.c

   1 /*
   2  * Copyright 2011 Analog Devices Inc.
   3  *
   4  * Licensed under the GPL-2.
   5  *
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/slab.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/irq.h>
  14 #include <linux/delay.h>
  15
  16 #include <asm/gptimers.h>
  17
  18 #include "../iio.h"
  19 #include "../trigger.h"
  20
  21 struct bfin_timer {
  22         unsigned short id, bit;
  23         unsigned long irqbit;
  24         int irq;
  25 };
  26
  27 /*
  28  * this covers all hardware timer configurations on
  29  * all Blackfin derivatives out there today
  30  */
  31
  32 static struct bfin_timer iio_bfin_timer_code[MAX_BLACKFIN_GPTIMERS] = {
  33         {TIMER0_id,  TIMER0bit,  TIMER_STATUS_TIMIL0,  IRQ_TIMER0},
  34         {TIMER1_id,  TIMER1bit,  TIMER_STATUS_TIMIL1,  IRQ_TIMER1},
  35         {TIMER2_id,  TIMER2bit,  TIMER_STATUS_TIMIL2,  IRQ_TIMER2},
  36 #if (MAX_BLACKFIN_GPTIMERS > 3)
  37         {TIMER3_id,  TIMER3bit,  TIMER_STATUS_TIMIL3,  IRQ_TIMER3},
  38         {TIMER4_id,  TIMER4bit,  TIMER_STATUS_TIMIL4,  IRQ_TIMER4},
  39         {TIMER5_id,  TIMER5bit,  TIMER_STATUS_TIMIL5,  IRQ_TIMER5},
  40         {TIMER6_id,  TIMER6bit,  TIMER_STATUS_TIMIL6,  IRQ_TIMER6},
  41         {TIMER7_id,  TIMER7bit,  TIMER_STATUS_TIMIL7,  IRQ_TIMER7},
  42 #endif
  43 #if (MAX_BLACKFIN_GPTIMERS > 8)
  44         {TIMER8_id,  TIMER8bit,  TIMER_STATUS_TIMIL8,  IRQ_TIMER8},
  45         {TIMER9_id,  TIMER9bit,  TIMER_STATUS_TIMIL9,  IRQ_TIMER9},
  46         {TIMER10_id, TIMER10bit, TIMER_STATUS_TIMIL10, IRQ_TIMER10},
  47 #if (MAX_BLACKFIN_GPTIMERS > 11)
  48         {TIMER11_id, TIMER11bit, TIMER_STATUS_TIMIL11, IRQ_TIMER11},
  49 #endif
  50 #endif
  51 };
  52
  53 struct bfin_tmr_state {
  54         struct iio_trigger *trig;
  55         struct bfin_timer *t;
  56         unsigned timer_num;
  57         int irq;
  58 };
  59
  60 static ssize_t iio_bfin_tmr_frequency_store(struct device *dev,
  61                 struct device_attribute *attr, const char *buf, size_t count)
  62 {
  63         struct iio_trigger *trig = dev_get_drvdata(dev);
  64         struct bfin_tmr_state *st = trig->private_data;
  65         long val;
  66         int ret;
  67
  68         ret = strict_strtoul(buf, 10, &val);
  69         if (ret)
  70                 goto error_ret;
  71
  72         if (val > 100000) {
  73                 ret = -EINVAL;
  74                 goto error_ret;
  75         }
  76
  77         disable_gptimers(st->t->bit);
  78
  79         if (!val)
  80                 goto error_ret;
  81
  82         val = get_sclk() / val;
  83         if (val <= 4) {
  84                 ret = -EINVAL;
  85                 goto error_ret;
  86         }
  87
  88         set_gptimer_period(st->t->id, val);
  89         set_gptimer_pwidth(st->t->id, 1);
  90         enable_gptimers(st->t->bit);
  91
  92 error_ret:
  93         return ret ? ret : count;
  94 }
  95
  96 static ssize_t iio_bfin_tmr_frequency_show(struct device *dev,
  97                                  struct device_attribute *attr,
  98                                  char *buf)
  99 {
 100         struct iio_trigger *trig = dev_get_drvdata(dev);
 101         struct bfin_tmr_state *st = trig->private_data;
 102
 103         return sprintf(buf, "%lu\n",
 104                         get_sclk() / get_gptimer_period(st->t->id));
 105 }
 106
 107 static DEVICE_ATTR(frequency, S_IRUGO | S_IWUSR, iio_bfin_tmr_frequency_show,
 108                    iio_bfin_tmr_frequency_store);
 109 static IIO_TRIGGER_NAME_ATTR;
 110
 111 static struct attribute *iio_bfin_tmr_trigger_attrs[] = {
 112         &dev_attr_frequency.attr,
 113         &dev_attr_name.attr,
 114         NULL,
 115 };
 116
 117 static const struct attribute_group iio_bfin_tmr_trigger_attr_group = {
 118         .attrs = iio_bfin_tmr_trigger_attrs,
 119 };
 120
 121
 122 static irqreturn_t iio_bfin_tmr_trigger_isr(int irq, void *devid)
 123 {
 124         struct bfin_tmr_state *st = devid;
 125
 126         clear_gptimer_intr(st->t->id);
 127         iio_trigger_poll(st->trig, 0);
 128
 129         return IRQ_HANDLED;
 130 }
 131
 132 static int iio_bfin_tmr_get_number(int irq)
 133 {
 134         int i;
 135
 136         for (i = 0; i < MAX_BLACKFIN_GPTIMERS; i++)
 137                 if (iio_bfin_timer_code[i].irq == irq)
 138                         return i;
 139
 140         return -ENODEV;
 141 }
 142
 143 static int __devinit iio_bfin_tmr_trigger_probe(struct platform_device *pdev)
 144 {
 145         struct bfin_tmr_state *st;
 146         int ret;
 147
 148         st = kzalloc(sizeof(*st), GFP_KERNEL);
 149         if (st == NULL) {
 150                 ret = -ENOMEM;
 151                 goto out;
 152         }
 153
 154         st->irq = platform_get_irq(pdev, 0);
 155         if (!st->irq) {
 156                 dev_err(&pdev->dev, "No IRQs specified");
 157                 ret = -ENODEV;
 158                 goto out1;
 159         }
 160
 161         ret = iio_bfin_tmr_get_number(st->irq);
 162         if (ret < 0)
 163                 goto out1;
 164
 165         st->timer_num = ret;
 166         st->t = &iio_bfin_timer_code[st->timer_num];
 167
 168         st->trig = iio_allocate_trigger();
 169         if (!st->trig) {
 170                 ret = -ENOMEM;
 171                 goto out1;
 172         }
 173
 174         st->trig->private_data = st;
 175         st->trig->control_attrs = &iio_bfin_tmr_trigger_attr_group;
 176         st->trig->owner = THIS_MODULE;
 177         st->trig->name = kasprintf(GFP_KERNEL, "bfintmr%d", st->timer_num);
 178         if (st->trig->name == NULL) {
 179                 ret = -ENOMEM;
 180                 goto out2;
 181         }
 182
 183         ret = iio_trigger_register(st->trig);
 184         if (ret)
 185                 goto out3;
 186
 187         ret = request_irq(st->irq, iio_bfin_tmr_trigger_isr,
 188                           0, st->trig->name, st);
 189         if (ret) {
 190                 dev_err(&pdev->dev,
 191                         "request IRQ-%d failed", st->irq);
 192                 goto out4;
 193         }
 194
 195         set_gptimer_config(st->t->id, OUT_DIS | PWM_OUT | PERIOD_CNT | IRQ_ENA);
 196
 197         dev_info(&pdev->dev, "iio trigger Blackfin TMR%d, IRQ-%d",
 198                  st->timer_num, st->irq);
 199         platform_set_drvdata(pdev, st);
 200
 201         return 0;
 202 out4:
 203         iio_trigger_unregister(st->trig);
 204 out3:
 205         kfree(st->trig->name);
 206 out2:
 207         iio_put_trigger(st->trig);
 208 out1:
 209         kfree(st);
 210 out:
 211         return ret;
 212 }
 213
 214 static int __devexit iio_bfin_tmr_trigger_remove(struct platform_device *pdev)
 215 {
 216         struct bfin_tmr_state *st = platform_get_drvdata(pdev);
 217
 218         disable_gptimers(st->t->bit);
 219         free_irq(st->irq, st);
 220         iio_trigger_unregister(st->trig);
 221         kfree(st->trig->name);
 222         iio_put_trigger(st->trig);
 223         kfree(st);
 224
 225         return 0;
 226 }
 227
 228 static struct platform_driver iio_bfin_tmr_trigger_driver = {
 229         .driver = {
 230                 .name = "iio_bfin_tmr_trigger",
 231                 .owner = THIS_MODULE,
 232         },
 233         .probe = iio_bfin_tmr_trigger_probe,
 234         .remove = __devexit_p(iio_bfin_tmr_trigger_remove),
 235 };
 236
 237 static int __init iio_bfin_tmr_trig_init(void)
 238 {
 239         return platform_driver_register(&iio_bfin_tmr_trigger_driver);
 240 }
 241 module_init(iio_bfin_tmr_trig_init);
 242
 243 static void __exit iio_bfin_tmr_trig_exit(void)
 244 {
 245         platform_driver_unregister(&iio_bfin_tmr_trigger_driver);
 246 }
 247 module_exit(iio_bfin_tmr_trig_exit);
 248
 249 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 250 MODULE_DESCRIPTION("Blackfin system timer based trigger for the iio subsystem");
 251 MODULE_LICENSE("GPL v2");
 252 MODULE_ALIAS("platform:iio-trig-bfin-timer");