staging: IIO: trigger: New Blackfin specific trigger driver iio-trig-bfin-timer
This driver allows any Blackfin system timer to be used as IIO trigger. It supports trigger rates from 0 to 100kHz in Hz resolution. Changes since V1: IIO: trigger: Apply review feedback Add comment explaining Blackfin hardware timer configurations Fix frequency_store, don't return -EINVAL for frequency set to 0 Signed-off-by: Michael Hennerich <michael.hennerich@analog.com> Acked-by: Jonathan Cameron <jic23@cam.ac.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Michael Hennerich
Greg Kroah-Hartman
Родитель
0772268aa9
Коммит
ea5dbf96db
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@ -28,4 +28,14 @@ config IIO_SYSFS_TRIGGER
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To compile this driver as a module, choose M here: the
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module will be called iio-trig-sysfs.
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config IIO_BFIN_TMR_TRIGGER
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tristate "Blackfin TIMER trigger"
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depends on BLACKFIN
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help
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Provides support for using a Blackfin timer as IIO triggers.
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If unsure, say N (but it's safe to say "Y").
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To compile this driver as a module, choose M here: the
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module will be called iio-trig-bfin-timer.
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endif # IIO_TRIGGER
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@ -5,3 +5,4 @@
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obj-$(CONFIG_IIO_PERIODIC_RTC_TRIGGER) += iio-trig-periodic-rtc.o
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obj-$(CONFIG_IIO_GPIO_TRIGGER) += iio-trig-gpio.o
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obj-$(CONFIG_IIO_SYSFS_TRIGGER) += iio-trig-sysfs.o
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obj-$(CONFIG_IIO_BFIN_TMR_TRIGGER) += iio-trig-bfin-timer.o
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@ -0,0 +1,252 @@
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/*
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* Copyright 2011 Analog Devices Inc.
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*
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* Licensed under the GPL-2.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/delay.h>
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#include <asm/gptimers.h>
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#include "../iio.h"
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#include "../trigger.h"
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struct bfin_timer {
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unsigned short id, bit;
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unsigned long irqbit;
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int irq;
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};
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/*
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* this covers all hardware timer configurations on
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* all Blackfin derivatives out there today
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*/
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static struct bfin_timer iio_bfin_timer_code[MAX_BLACKFIN_GPTIMERS] = {
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{TIMER0_id, TIMER0bit, TIMER_STATUS_TIMIL0, IRQ_TIMER0},
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{TIMER1_id, TIMER1bit, TIMER_STATUS_TIMIL1, IRQ_TIMER1},
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{TIMER2_id, TIMER2bit, TIMER_STATUS_TIMIL2, IRQ_TIMER2},
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#if (MAX_BLACKFIN_GPTIMERS > 3)
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{TIMER3_id, TIMER3bit, TIMER_STATUS_TIMIL3, IRQ_TIMER3},
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{TIMER4_id, TIMER4bit, TIMER_STATUS_TIMIL4, IRQ_TIMER4},
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{TIMER5_id, TIMER5bit, TIMER_STATUS_TIMIL5, IRQ_TIMER5},
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{TIMER6_id, TIMER6bit, TIMER_STATUS_TIMIL6, IRQ_TIMER6},
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{TIMER7_id, TIMER7bit, TIMER_STATUS_TIMIL7, IRQ_TIMER7},
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#endif
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#if (MAX_BLACKFIN_GPTIMERS > 8)
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{TIMER8_id, TIMER8bit, TIMER_STATUS_TIMIL8, IRQ_TIMER8},
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{TIMER9_id, TIMER9bit, TIMER_STATUS_TIMIL9, IRQ_TIMER9},
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{TIMER10_id, TIMER10bit, TIMER_STATUS_TIMIL10, IRQ_TIMER10},
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#if (MAX_BLACKFIN_GPTIMERS > 11)
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{TIMER11_id, TIMER11bit, TIMER_STATUS_TIMIL11, IRQ_TIMER11},
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#endif
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#endif
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};
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struct bfin_tmr_state {
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struct iio_trigger *trig;
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struct bfin_timer *t;
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unsigned timer_num;
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int irq;
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};
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static ssize_t iio_bfin_tmr_frequency_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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struct iio_trigger *trig = dev_get_drvdata(dev);
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struct bfin_tmr_state *st = trig->private_data;
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long val;
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int ret;
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ret = strict_strtoul(buf, 10, &val);
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if (ret)
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goto error_ret;
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if (val > 100000) {
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ret = -EINVAL;
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goto error_ret;
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}
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disable_gptimers(st->t->bit);
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if (!val)
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goto error_ret;
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val = get_sclk() / val;
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if (val <= 4) {
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ret = -EINVAL;
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goto error_ret;
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}
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set_gptimer_period(st->t->id, val);
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set_gptimer_pwidth(st->t->id, 1);
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enable_gptimers(st->t->bit);
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error_ret:
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return ret ? ret : count;
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}
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static ssize_t iio_bfin_tmr_frequency_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct iio_trigger *trig = dev_get_drvdata(dev);
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struct bfin_tmr_state *st = trig->private_data;
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return sprintf(buf, "%lu\n",
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get_sclk() / get_gptimer_period(st->t->id));
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}
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static DEVICE_ATTR(frequency, S_IRUGO | S_IWUSR, iio_bfin_tmr_frequency_show,
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iio_bfin_tmr_frequency_store);
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static IIO_TRIGGER_NAME_ATTR;
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static struct attribute *iio_bfin_tmr_trigger_attrs[] = {
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&dev_attr_frequency.attr,
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&dev_attr_name.attr,
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NULL,
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};
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static const struct attribute_group iio_bfin_tmr_trigger_attr_group = {
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.attrs = iio_bfin_tmr_trigger_attrs,
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};
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static irqreturn_t iio_bfin_tmr_trigger_isr(int irq, void *devid)
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{
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struct bfin_tmr_state *st = devid;
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clear_gptimer_intr(st->t->id);
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iio_trigger_poll(st->trig, 0);
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return IRQ_HANDLED;
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}
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static int iio_bfin_tmr_get_number(int irq)
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{
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int i;
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for (i = 0; i < MAX_BLACKFIN_GPTIMERS; i++)
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if (iio_bfin_timer_code[i].irq == irq)
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return i;
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return -ENODEV;
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}
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static int __devinit iio_bfin_tmr_trigger_probe(struct platform_device *pdev)
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{
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struct bfin_tmr_state *st;
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int ret;
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st = kzalloc(sizeof(*st), GFP_KERNEL);
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if (st == NULL) {
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ret = -ENOMEM;
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goto out;
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}
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st->irq = platform_get_irq(pdev, 0);
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if (!st->irq) {
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dev_err(&pdev->dev, "No IRQs specified");
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ret = -ENODEV;
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goto out1;
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}
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ret = iio_bfin_tmr_get_number(st->irq);
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if (ret < 0)
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goto out1;
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st->timer_num = ret;
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st->t = &iio_bfin_timer_code[st->timer_num];
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st->trig = iio_allocate_trigger();
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if (!st->trig) {
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ret = -ENOMEM;
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goto out1;
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}
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st->trig->private_data = st;
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st->trig->control_attrs = &iio_bfin_tmr_trigger_attr_group;
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st->trig->owner = THIS_MODULE;
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st->trig->name = kasprintf(GFP_KERNEL, "bfintmr%d", st->timer_num);
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if (st->trig->name == NULL) {
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ret = -ENOMEM;
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goto out2;
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}
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ret = iio_trigger_register(st->trig);
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if (ret)
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goto out3;
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ret = request_irq(st->irq, iio_bfin_tmr_trigger_isr,
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0, st->trig->name, st);
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if (ret) {
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dev_err(&pdev->dev,
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"request IRQ-%d failed", st->irq);
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goto out4;
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}
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set_gptimer_config(st->t->id, OUT_DIS | PWM_OUT | PERIOD_CNT | IRQ_ENA);
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dev_info(&pdev->dev, "iio trigger Blackfin TMR%d, IRQ-%d",
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st->timer_num, st->irq);
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platform_set_drvdata(pdev, st);
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return 0;
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out4:
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iio_trigger_unregister(st->trig);
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out3:
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kfree(st->trig->name);
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out2:
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iio_put_trigger(st->trig);
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out1:
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kfree(st);
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out:
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return ret;
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}
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static int __devexit iio_bfin_tmr_trigger_remove(struct platform_device *pdev)
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{
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struct bfin_tmr_state *st = platform_get_drvdata(pdev);
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disable_gptimers(st->t->bit);
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free_irq(st->irq, st);
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iio_trigger_unregister(st->trig);
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kfree(st->trig->name);
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iio_put_trigger(st->trig);
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kfree(st);
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return 0;
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}
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static struct platform_driver iio_bfin_tmr_trigger_driver = {
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.driver = {
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.name = "iio_bfin_tmr_trigger",
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.owner = THIS_MODULE,
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},
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.probe = iio_bfin_tmr_trigger_probe,
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.remove = __devexit_p(iio_bfin_tmr_trigger_remove),
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};
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static int __init iio_bfin_tmr_trig_init(void)
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{
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return platform_driver_register(&iio_bfin_tmr_trigger_driver);
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}
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module_init(iio_bfin_tmr_trig_init);
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static void __exit iio_bfin_tmr_trig_exit(void)
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{
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platform_driver_unregister(&iio_bfin_tmr_trigger_driver);
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}
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module_exit(iio_bfin_tmr_trig_exit);
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MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
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MODULE_DESCRIPTION("Blackfin system timer based trigger for the iio subsystem");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("platform:iio-trig-bfin-timer");
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