Merge tag 'iio-fixes-for-3.11b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-linus
Jonathan writes:
Second round of IIO fixes for the 3.11 cycle.
1) Fix a long term race in the IIO trigger handling.
This only effects cases where a single trigger is in use
by multiple devices.
2) ti_am335x fix an issue with incorrect data due to reading before
the sequencer is finished.
diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
index 0ad208a..3ceac3e 100644
--- a/drivers/iio/adc/ti_am335x_adc.c
+++ b/drivers/iio/adc/ti_am335x_adc.c
@@ -60,7 +60,6 @@
{
unsigned int stepconfig;
int i, steps;
- u32 step_en;
/*
* There are 16 configurable steps and 8 analog input
@@ -86,8 +85,7 @@
adc_dev->channel_step[i] = steps;
steps++;
}
- step_en = get_adc_step_mask(adc_dev);
- am335x_tsc_se_set(adc_dev->mfd_tscadc, step_en);
+
}
static const char * const chan_name_ain[] = {
@@ -142,10 +140,22 @@
int *val, int *val2, long mask)
{
struct tiadc_device *adc_dev = iio_priv(indio_dev);
- int i;
- unsigned int fifo1count, read;
+ int i, map_val;
+ unsigned int fifo1count, read, stepid;
u32 step = UINT_MAX;
bool found = false;
+ u32 step_en;
+ unsigned long timeout = jiffies + usecs_to_jiffies
+ (IDLE_TIMEOUT * adc_dev->channels);
+ step_en = get_adc_step_mask(adc_dev);
+ am335x_tsc_se_set(adc_dev->mfd_tscadc, step_en);
+
+ /* Wait for ADC sequencer to complete sampling */
+ while (tiadc_readl(adc_dev, REG_ADCFSM) & SEQ_STATUS) {
+ if (time_after(jiffies, timeout))
+ return -EAGAIN;
+ }
+ map_val = chan->channel + TOTAL_CHANNELS;
/*
* When the sub-system is first enabled,
@@ -170,12 +180,16 @@
fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
for (i = 0; i < fifo1count; i++) {
read = tiadc_readl(adc_dev, REG_FIFO1);
- if (read >> 16 == step) {
- *val = read & 0xfff;
+ stepid = read & FIFOREAD_CHNLID_MASK;
+ stepid = stepid >> 0x10;
+
+ if (stepid == map_val) {
+ read = read & FIFOREAD_DATA_MASK;
found = true;
+ *val = read;
}
}
- am335x_tsc_se_update(adc_dev->mfd_tscadc);
+
if (found == false)
return -EBUSY;
return IIO_VAL_INT;
diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c
index ea8a414..0dd9bb8 100644
--- a/drivers/iio/industrialio-trigger.c
+++ b/drivers/iio/industrialio-trigger.c
@@ -127,12 +127,17 @@
void iio_trigger_poll(struct iio_trigger *trig, s64 time)
{
int i;
- if (!trig->use_count)
- for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
- if (trig->subirqs[i].enabled) {
- trig->use_count++;
+
+ if (!atomic_read(&trig->use_count)) {
+ atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
+
+ for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
+ if (trig->subirqs[i].enabled)
generic_handle_irq(trig->subirq_base + i);
- }
+ else
+ iio_trigger_notify_done(trig);
+ }
+ }
}
EXPORT_SYMBOL(iio_trigger_poll);
@@ -146,19 +151,24 @@
void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time)
{
int i;
- if (!trig->use_count)
- for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
- if (trig->subirqs[i].enabled) {
- trig->use_count++;
+
+ if (!atomic_read(&trig->use_count)) {
+ atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
+
+ for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
+ if (trig->subirqs[i].enabled)
handle_nested_irq(trig->subirq_base + i);
- }
+ else
+ iio_trigger_notify_done(trig);
+ }
+ }
}
EXPORT_SYMBOL(iio_trigger_poll_chained);
void iio_trigger_notify_done(struct iio_trigger *trig)
{
- trig->use_count--;
- if (trig->use_count == 0 && trig->ops && trig->ops->try_reenable)
+ if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
+ trig->ops->try_reenable)
if (trig->ops->try_reenable(trig))
/* Missed an interrupt so launch new poll now */
iio_trigger_poll(trig, 0);
diff --git a/include/linux/iio/trigger.h b/include/linux/iio/trigger.h
index 3869c52..369cf2c 100644
--- a/include/linux/iio/trigger.h
+++ b/include/linux/iio/trigger.h
@@ -8,6 +8,7 @@
*/
#include <linux/irq.h>
#include <linux/module.h>
+#include <linux/atomic.h>
#ifndef _IIO_TRIGGER_H_
#define _IIO_TRIGGER_H_
@@ -61,7 +62,7 @@
struct list_head list;
struct list_head alloc_list;
- int use_count;
+ atomic_t use_count;
struct irq_chip subirq_chip;
int subirq_base;
diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
index 8d73fe2..db1791b 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/include/linux/mfd/ti_am335x_tscadc.h
@@ -113,11 +113,27 @@
#define CNTRLREG_8WIRE CNTRLREG_AFE_CTRL(3)
#define CNTRLREG_TSCENB BIT(7)
+/* FIFO READ Register */
+#define FIFOREAD_DATA_MASK (0xfff << 0)
+#define FIFOREAD_CHNLID_MASK (0xf << 16)
+
+/* Sequencer Status */
+#define SEQ_STATUS BIT(5)
+
#define ADC_CLK 3000000
#define MAX_CLK_DIV 7
#define TOTAL_STEPS 16
#define TOTAL_CHANNELS 8
+/*
+* ADC runs at 3MHz, and it takes
+* 15 cycles to latch one data output.
+* Hence the idle time for ADC to
+* process one sample data would be
+* around 5 micro seconds.
+*/
+#define IDLE_TIMEOUT 5 /* microsec */
+
#define TSCADC_CELLS 2
struct ti_tscadc_dev {