Eric Lee / smarc-fsl-linux-kernel

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Documentation/blackfin/gptimers-example.c 2 KB
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  /*
   * Simple gptimers example
   *	http://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:drivers:gptimers
   *
   * Copyright 2007-2009 Analog Devices Inc.
   *
   * Licensed under the GPL-2 or later.
   */
  
  #include <linux/interrupt.h>
  #include <linux/module.h>
  
  #include <asm/gptimers.h>
  #include <asm/portmux.h>
  
  /* ... random driver includes ... */
  
  #define DRIVER_NAME "gptimer_example"
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  #ifdef IRQ_TIMER5
  #define SAMPLE_IRQ_TIMER IRQ_TIMER5
  #else
  #define SAMPLE_IRQ_TIMER IRQ_TIMER2
  #endif
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  struct gptimer_data {
  	uint32_t period, width;
  };
  static struct gptimer_data data;
  
  /* ... random driver state ... */
  
  static irqreturn_t gptimer_example_irq(int irq, void *dev_id)
  {
  	struct gptimer_data *data = dev_id;
  
  	/* make sure it was our timer which caused the interrupt */
  	if (!get_gptimer_intr(TIMER5_id))
  		return IRQ_NONE;
  
  	/* read the width/period values that were captured for the waveform */
  	data->width = get_gptimer_pwidth(TIMER5_id);
  	data->period = get_gptimer_period(TIMER5_id);
  
  	/* acknowledge the interrupt */
  	clear_gptimer_intr(TIMER5_id);
  
  	/* tell the upper layers we took care of things */
  	return IRQ_HANDLED;
  }
  
  /* ... random driver code ... */
  
  static int __init gptimer_example_init(void)
  {
  	int ret;
  
  	/* grab the peripheral pins */
  	ret = peripheral_request(P_TMR5, DRIVER_NAME);
  	if (ret) {
  		printk(KERN_NOTICE DRIVER_NAME ": peripheral request failed
  ");
  		return ret;
  	}
  
  	/* grab the IRQ for the timer */
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  	ret = request_irq(SAMPLE_IRQ_TIMER, gptimer_example_irq,
  			IRQF_SHARED, DRIVER_NAME, &data);
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  	if (ret) {
  		printk(KERN_NOTICE DRIVER_NAME ": IRQ request failed
  ");
  		peripheral_free(P_TMR5);
  		return ret;
  	}
  
  	/* setup the timer and enable it */
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  	set_gptimer_config(TIMER5_id,
  			WDTH_CAP | PULSE_HI | PERIOD_CNT | IRQ_ENA);
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  	enable_gptimers(TIMER5bit);
  
  	return 0;
  }
  module_init(gptimer_example_init);
  
  static void __exit gptimer_example_exit(void)
  {
  	disable_gptimers(TIMER5bit);
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  	free_irq(SAMPLE_IRQ_TIMER, &data);
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  	peripheral_free(P_TMR5);
  }
  module_exit(gptimer_example_exit);
  
  MODULE_LICENSE("BSD");