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.
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@xxxxxxxxxx>
Acked-by: Jonathan Cameron <jic23@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/staging/iio/trigger/Kconfig | 10 +
drivers/staging/iio/trigger/Makefile | 1 +
drivers/staging/iio/trigger/iio-trig-bfin-timer.c | 252 +++++++++++++++++++++
3 files changed, 263 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..583bef0
--- /dev/null
+++ b/drivers/staging/iio/trigger/iio-trig-bfin-timer.c
@@ -0,0 +1,252 @@
+/*
+ * 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;
+};
+
+/*
+ * this covers all hardware timer configurations on
+ * all Blackfin derivatives out there today
+ */
+
+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
+};
+
+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;
+
+ if (val > 100000) {
+ ret = -EINVAL;
+ goto error_ret;
+ }
+
+ disable_gptimers(st->t->bit);
+
+ if (!val)
+ 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");
--
1.7.4.1
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