On 02/16/11 13:42, michael.hennerich@xxxxxxxxxx wrote:
> From: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
>
> This driver allows any Blackfin system timer to be used as IIO trigger.
> It supports trigger rates from 0 to 100kHz in Hz resolution.
Hi Michael,
The reason we ended up with a rtc based trigger in the first place, was that
I had a very similar set of timers on the pxa271 that I mainly develop with.
At the time some debate opened up on whether there was a use case here for
a more general way of providing access to system periodic timers for exactly
this sort of device. The view seemed to be that there was, but I certainly didn't
have time to do it at the time and no one else seems to have looked at it since.
My dirty solution was an rtc driver that just added a lot of rtcs. It was never
going to merge though...
Right now I can only track down a previous email from myself saying this has
been discussed a number of times, but naturally with no references at all. Oops.
Anyhow, such a general subsystem for cpu timers doesn't exist AFAIK so for now
lets just go with your approach. Perhaps if we find other possible users we can
talk again about how best to support these.
>
Looks good to me. Ideally if someone else could ack from the blackfin side
of things that would probably be a good idea as I don't know that platform
at all. Looks simple enough that I'm not going to insist on that though if
no one suitable has the time.
Please clean up the #if #endif bit and then I'm happy for this to merge.
> Signed-off-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
Acked-by: Jonathan Cameron <jic23@xxxxxxxxx>
> ---
> drivers/staging/iio/trigger/Kconfig | 10 +
> drivers/staging/iio/trigger/Makefile | 1 +
> drivers/staging/iio/trigger/iio-trig-bfin-timer.c | 244 +++++++++++++++++++++
> 3 files changed, 255 insertions(+), 0 deletions(-)
> create mode 100644 drivers/staging/iio/trigger/iio-trig-bfin-timer.c
>
> diff --git a/drivers/staging/iio/trigger/Kconfig b/drivers/staging/iio/trigger/Kconfig
> index 3a82013..c33777e 100644
> --- a/drivers/staging/iio/trigger/Kconfig
> +++ b/drivers/staging/iio/trigger/Kconfig
> @@ -28,4 +28,14 @@ config IIO_SYSFS_TRIGGER
> To compile this driver as a module, choose M here: the
> module will be called iio-trig-sysfs.
>
> +config IIO_BFIN_TMR_TRIGGER
> + tristate "Blackfin TIMER trigger"
> + depends on BLACKFIN
> + help
> + Provides support for using a Blackfin timer as IIO triggers.
> + If unsure, say N (but it's safe to say "Y").
> +
> + To compile this driver as a module, choose M here: the
> + module will be called iio-trig-bfin-timer.
> +
> endif # IIO_TRIGGER
> diff --git a/drivers/staging/iio/trigger/Makefile b/drivers/staging/iio/trigger/Makefile
> index 504b9c0..b088b57 100644
> --- a/drivers/staging/iio/trigger/Makefile
> +++ b/drivers/staging/iio/trigger/Makefile
> @@ -5,3 +5,4 @@
> obj-$(CONFIG_IIO_PERIODIC_RTC_TRIGGER) += iio-trig-periodic-rtc.o
> obj-$(CONFIG_IIO_GPIO_TRIGGER) += iio-trig-gpio.o
> obj-$(CONFIG_IIO_SYSFS_TRIGGER) += iio-trig-sysfs.o
> +obj-$(CONFIG_IIO_BFIN_TMR_TRIGGER) += iio-trig-bfin-timer.o
> diff --git a/drivers/staging/iio/trigger/iio-trig-bfin-timer.c b/drivers/staging/iio/trigger/iio-trig-bfin-timer.c
> new file mode 100644
> index 0000000..afcfc7a
> --- /dev/null
> +++ b/drivers/staging/iio/trigger/iio-trig-bfin-timer.c
> @@ -0,0 +1,244 @@
> +/*
> + * Copyright 2011 Analog Devices Inc.
> + *
> + * Licensed under the GPL-2.
> + *
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/delay.h>
> +
> +#include <asm/gptimers.h>
> +
> +#include "../iio.h"
> +#include "../trigger.h"
> +
> +struct bfin_timer {
> + unsigned short id, bit;
> + unsigned long irqbit;
> + int irq;
> +};
> +
> +static struct bfin_timer iio_bfin_timer_code[MAX_BLACKFIN_GPTIMERS] = {
> + {TIMER0_id, TIMER0bit, TIMER_STATUS_TIMIL0, IRQ_TIMER0},
> + {TIMER1_id, TIMER1bit, TIMER_STATUS_TIMIL1, IRQ_TIMER1},
> + {TIMER2_id, TIMER2bit, TIMER_STATUS_TIMIL2, IRQ_TIMER2},
> +#if (MAX_BLACKFIN_GPTIMERS > 3)
> + {TIMER3_id, TIMER3bit, TIMER_STATUS_TIMIL3, IRQ_TIMER3},
> + {TIMER4_id, TIMER4bit, TIMER_STATUS_TIMIL4, IRQ_TIMER4},
> + {TIMER5_id, TIMER5bit, TIMER_STATUS_TIMIL5, IRQ_TIMER5},
> + {TIMER6_id, TIMER6bit, TIMER_STATUS_TIMIL6, IRQ_TIMER6},
> + {TIMER7_id, TIMER7bit, TIMER_STATUS_TIMIL7, IRQ_TIMER7},
> +#endif
> +#if (MAX_BLACKFIN_GPTIMERS > 8)
> + {TIMER8_id, TIMER8bit, TIMER_STATUS_TIMIL8, IRQ_TIMER8},
> + {TIMER9_id, TIMER9bit, TIMER_STATUS_TIMIL9, IRQ_TIMER9},
> + {TIMER10_id, TIMER10bit, TIMER_STATUS_TIMIL10, IRQ_TIMER10},
> +#if (MAX_BLACKFIN_GPTIMERS > 11)
> + {TIMER11_id, TIMER11bit, TIMER_STATUS_TIMIL11, IRQ_TIMER11},
> +#endif
> +#endif
Can we have some consistency in your #if #endif approach in here.
Given this is compile time anyway, just have the #if #endif pair around
each set.
Ouch I'm guessing the completely different IRQ maps for the different
blackfin chips is a real pain if you ever want to compile a kernel
that will run on several different ones!
> +};
> +
> +struct bfin_tmr_state {
> + struct iio_trigger *trig;
> + struct bfin_timer *t;
> + unsigned timer_num;
> + int irq;
> +};
> +
> +static ssize_t iio_bfin_tmr_frequency_store(struct device *dev,
> + struct device_attribute *attr, const char *buf, size_t count)
> +{
> + struct iio_trigger *trig = dev_get_drvdata(dev);
> + struct bfin_tmr_state *st = trig->private_data;
> + long val;
> + int ret;
> +
> + ret = strict_strtoul(buf, 10, &val);
> + if (ret)
> + goto error_ret;
> +
> + disable_gptimers(st->t->bit);
> +
> + if (val <= 0 || val > 100000) {
> + ret = -EINVAL;
> + goto error_ret;
> + }
> +
> + val = get_sclk() / val;
> + if (val <= 4) {
> + ret = -EINVAL;
> + goto error_ret;
> + }
> +
> + set_gptimer_period(st->t->id, val);
> + set_gptimer_pwidth(st->t->id, 1);
> + enable_gptimers(st->t->bit);
> +
> +error_ret:
> + return ret ? ret : count;
> +}
> +
> +static ssize_t iio_bfin_tmr_frequency_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct iio_trigger *trig = dev_get_drvdata(dev);
> + struct bfin_tmr_state *st = trig->private_data;
> +
> + return sprintf(buf, "%lu\n",
> + get_sclk() / get_gptimer_period(st->t->id));
> +}
> +
> +static DEVICE_ATTR(frequency, S_IRUGO | S_IWUSR, iio_bfin_tmr_frequency_show,
> + iio_bfin_tmr_frequency_store);
> +static IIO_TRIGGER_NAME_ATTR;
> +
> +static struct attribute *iio_bfin_tmr_trigger_attrs[] = {
> + &dev_attr_frequency.attr,
> + &dev_attr_name.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group iio_bfin_tmr_trigger_attr_group = {
> + .attrs = iio_bfin_tmr_trigger_attrs,
> +};
> +
> +
> +static irqreturn_t iio_bfin_tmr_trigger_isr(int irq, void *devid)
> +{
> + struct bfin_tmr_state *st = devid;
> +
> + clear_gptimer_intr(st->t->id);
> + iio_trigger_poll(st->trig, 0);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int iio_bfin_tmr_get_number(int irq)
> +{
> + int i;
> +
> + for (i = 0; i < MAX_BLACKFIN_GPTIMERS; i++)
> + if (iio_bfin_timer_code[i].irq == irq)
> + return i;
> +
> + return -ENODEV;
> +}
> +
> +static int __devinit iio_bfin_tmr_trigger_probe(struct platform_device *pdev)
> +{
> + struct bfin_tmr_state *st;
> + int ret;
> +
> + st = kzalloc(sizeof(*st), GFP_KERNEL);
> + if (st == NULL) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + st->irq = platform_get_irq(pdev, 0);
> + if (!st->irq) {
> + dev_err(&pdev->dev, "No IRQs specified");
> + ret = -ENODEV;
> + goto out1;
> + }
> +
> + ret = iio_bfin_tmr_get_number(st->irq);
> + if (ret < 0)
> + goto out1;
> +
> + st->timer_num = ret;
> + st->t = &iio_bfin_timer_code[st->timer_num];
> +
> + st->trig = iio_allocate_trigger();
> + if (!st->trig) {
> + ret = -ENOMEM;
> + goto out1;
> + }
> +
> + st->trig->private_data = st;
> + st->trig->control_attrs = &iio_bfin_tmr_trigger_attr_group;
> + st->trig->owner = THIS_MODULE;
> + st->trig->name = kasprintf(GFP_KERNEL, "bfintmr%d", st->timer_num);
> + if (st->trig->name == NULL) {
> + ret = -ENOMEM;
> + goto out2;
> + }
> +
> + ret = iio_trigger_register(st->trig);
> + if (ret)
> + goto out3;
> +
> + ret = request_irq(st->irq, iio_bfin_tmr_trigger_isr,
> + 0, st->trig->name, st);
> + if (ret) {
> + dev_err(&pdev->dev,
> + "request IRQ-%d failed", st->irq);
> + goto out4;
> + }
> +
> + set_gptimer_config(st->t->id, OUT_DIS | PWM_OUT | PERIOD_CNT | IRQ_ENA);
> +
> + dev_info(&pdev->dev, "iio trigger Blackfin TMR%d, IRQ-%d",
> + st->timer_num, st->irq);
> + platform_set_drvdata(pdev, st);
> +
> + return 0;
> +out4:
> + iio_trigger_unregister(st->trig);
> +out3:
> + kfree(st->trig->name);
> +out2:
> + iio_put_trigger(st->trig);
> +out1:
> + kfree(st);
> +out:
> + return ret;
> +}
> +
> +static int __devexit iio_bfin_tmr_trigger_remove(struct platform_device *pdev)
> +{
> + struct bfin_tmr_state *st = platform_get_drvdata(pdev);
> +
> + disable_gptimers(st->t->bit);
> + free_irq(st->irq, st);
> + iio_trigger_unregister(st->trig);
> + kfree(st->trig->name);
> + iio_put_trigger(st->trig);
> + kfree(st);
> +
> + return 0;
> +}
> +
> +static struct platform_driver iio_bfin_tmr_trigger_driver = {
> + .driver = {
> + .name = "iio_bfin_tmr_trigger",
> + .owner = THIS_MODULE,
> + },
> + .probe = iio_bfin_tmr_trigger_probe,
> + .remove = __devexit_p(iio_bfin_tmr_trigger_remove),
> +};
> +
> +static int __init iio_bfin_tmr_trig_init(void)
> +{
> + return platform_driver_register(&iio_bfin_tmr_trigger_driver);
> +}
> +module_init(iio_bfin_tmr_trig_init);
> +
> +static void __exit iio_bfin_tmr_trig_exit(void)
> +{
> + platform_driver_unregister(&iio_bfin_tmr_trigger_driver);
> +}
> +module_exit(iio_bfin_tmr_trig_exit);
> +
> +MODULE_AUTHOR("Michael Hennerich <hennerich@xxxxxxxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Blackfin system timer based trigger for the iio subsystem");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:iio-trig-bfin-timer");
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