Documentation/blackfin/gptimers-example.c

   1 /*
   2  * Simple gptimers example
   3  *      http://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:drivers:gptimers
   4  *
   5  * Copyright 2007-2009 Analog Devices Inc.
   6  *
   7  * Licensed under the GPL-2 or later.
   8  */
   9
  10 #include <linux/interrupt.h>
  11 #include <linux/module.h>
  12
  13 #include <asm/gptimers.h>
  14 #include <asm/portmux.h>
  15
  16 /* ... random driver includes ... */
  17
  18 #define DRIVER_NAME "gptimer_example"
  19
  20 struct gptimer_data {
  21         uint32_t period, width;
  22 };
  23 static struct gptimer_data data;
  24
  25 /* ... random driver state ... */
  26
  27 static irqreturn_t gptimer_example_irq(int irq, void *dev_id)
  28 {
  29         struct gptimer_data *data = dev_id;
  30
  31         /* make sure it was our timer which caused the interrupt */
  32         if (!get_gptimer_intr(TIMER5_id))
  33                 return IRQ_NONE;
  34
  35         /* read the width/period values that were captured for the waveform */
  36         data->width = get_gptimer_pwidth(TIMER5_id);
  37         data->period = get_gptimer_period(TIMER5_id);
  38
  39         /* acknowledge the interrupt */
  40         clear_gptimer_intr(TIMER5_id);
  41
  42         /* tell the upper layers we took care of things */
  43         return IRQ_HANDLED;
  44 }
  45
  46 /* ... random driver code ... */
  47
  48 static int __init gptimer_example_init(void)
  49 {
  50         int ret;
  51
  52         /* grab the peripheral pins */
  53         ret = peripheral_request(P_TMR5, DRIVER_NAME);
  54         if (ret) {
  55                 printk(KERN_NOTICE DRIVER_NAME ": peripheral request failed\n");
  56                 return ret;
  57         }
  58
  59         /* grab the IRQ for the timer */
  60         ret = request_irq(IRQ_TIMER5, gptimer_example_irq, IRQF_SHARED, DRIVER_NAME, &data);
  61         if (ret) {
  62                 printk(KERN_NOTICE DRIVER_NAME ": IRQ request failed\n");
  63                 peripheral_free(P_TMR5);
  64                 return ret;
  65         }
  66
  67         /* setup the timer and enable it */
  68         set_gptimer_config(TIMER5_id, WDTH_CAP | PULSE_HI | PERIOD_CNT | IRQ_ENA);
  69         enable_gptimers(TIMER5bit);
  70
  71         return 0;
  72 }
  73 module_init(gptimer_example_init);
  74
  75 static void __exit gptimer_example_exit(void)
  76 {
  77         disable_gptimers(TIMER5bit);
  78         free_irq(IRQ_TIMER5, &data);
  79         peripheral_free(P_TMR5);
  80 }
  81 module_exit(gptimer_example_exit);
  82
  83 MODULE_LICENSE("BSD");