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 <linux/iio/iio.h>
  19 #include <linux/iio/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
 110 static struct attribute *iio_bfin_tmr_trigger_attrs[] = {
 111         &dev_attr_frequency.attr,
 112         NULL,
 113 };
 114
 115 static const struct attribute_group iio_bfin_tmr_trigger_attr_group = {
 116         .attrs = iio_bfin_tmr_trigger_attrs,
 117 };
 118
 119 static const struct attribute_group *iio_bfin_tmr_trigger_attr_groups[] = {
 120         &iio_bfin_tmr_trigger_attr_group,
 121         NULL
 122 };
 123
 124
 125 static irqreturn_t iio_bfin_tmr_trigger_isr(int irq, void *devid)
 126 {
 127         struct bfin_tmr_state *st = devid;
 128
 129         clear_gptimer_intr(st->t->id);
 130         iio_trigger_poll(st->trig, 0);
 131
 132         return IRQ_HANDLED;
 133 }
 134
 135 static int iio_bfin_tmr_get_number(int irq)
 136 {
 137         int i;
 138
 139         for (i = 0; i < MAX_BLACKFIN_GPTIMERS; i++)
 140                 if (iio_bfin_timer_code[i].irq == irq)
 141                         return i;
 142
 143         return -ENODEV;
 144 }
 145
 146 static const struct iio_trigger_ops iio_bfin_tmr_trigger_ops = {
 147         .owner = THIS_MODULE,
 148 };
 149
 150 static int __devinit iio_bfin_tmr_trigger_probe(struct platform_device *pdev)
 151 {
 152         struct bfin_tmr_state *st;
 153         int ret;
 154
 155         st = kzalloc(sizeof(*st), GFP_KERNEL);
 156         if (st == NULL) {
 157                 ret = -ENOMEM;
 158                 goto out;
 159         }
 160
 161         st->irq = platform_get_irq(pdev, 0);
 162         if (!st->irq) {
 163                 dev_err(&pdev->dev, "No IRQs specified");
 164                 ret = -ENODEV;
 165                 goto out1;
 166         }
 167
 168         ret = iio_bfin_tmr_get_number(st->irq);
 169         if (ret < 0)
 170                 goto out1;
 171
 172         st->timer_num = ret;
 173         st->t = &iio_bfin_timer_code[st->timer_num];
 174
 175         st->trig = iio_trigger_alloc("bfintmr%d", st->timer_num);
 176         if (!st->trig) {
 177                 ret = -ENOMEM;
 178                 goto out1;
 179         }
 180
 181         st->trig->private_data = st;
 182         st->trig->ops = &iio_bfin_tmr_trigger_ops;
 183         st->trig->dev.groups = iio_bfin_tmr_trigger_attr_groups;
 184         ret = iio_trigger_register(st->trig);
 185         if (ret)
 186                 goto out2;
 187
 188         ret = request_irq(st->irq, iio_bfin_tmr_trigger_isr,
 189                           0, st->trig->name, st);
 190         if (ret) {
 191                 dev_err(&pdev->dev,
 192                         "request IRQ-%d failed", st->irq);
 193                 goto out4;
 194         }
 195
 196         set_gptimer_config(st->t->id, OUT_DIS | PWM_OUT | PERIOD_CNT | IRQ_ENA);
 197
 198         dev_info(&pdev->dev, "iio trigger Blackfin TMR%d, IRQ-%d",
 199                  st->timer_num, st->irq);
 200         platform_set_drvdata(pdev, st);
 201
 202         return 0;
 203 out4:
 204         iio_trigger_unregister(st->trig);
 205 out2:
 206         iio_trigger_put(st->trig);
 207 out1:
 208         kfree(st);
 209 out:
 210         return ret;
 211 }
 212
 213 static int __devexit iio_bfin_tmr_trigger_remove(struct platform_device *pdev)
 214 {
 215         struct bfin_tmr_state *st = platform_get_drvdata(pdev);
 216
 217         disable_gptimers(st->t->bit);
 218         free_irq(st->irq, st);
 219         iio_trigger_unregister(st->trig);
 220         iio_trigger_put(st->trig);
 221         kfree(st);
 222
 223         return 0;
 224 }
 225
 226 static struct platform_driver iio_bfin_tmr_trigger_driver = {
 227         .driver = {
 228                 .name = "iio_bfin_tmr_trigger",
 229                 .owner = THIS_MODULE,
 230         },
 231         .probe = iio_bfin_tmr_trigger_probe,
 232         .remove = __devexit_p(iio_bfin_tmr_trigger_remove),
 233 };
 234
 235 module_platform_driver(iio_bfin_tmr_trigger_driver);
 236
 237 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 238 MODULE_DESCRIPTION("Blackfin system timer based trigger for the iio subsystem");
 239 MODULE_LICENSE("GPL v2");
 240 MODULE_ALIAS("platform:iio-trig-bfin-timer");