[PATCH 2/3] iio: adc: at91-sama5d2_adc: add hw trigger and buffer support
Eugen Hristev
eugen.hristev at microchip.com
Wed Apr 19 04:20:44 EDT 2017
Added support for the external hardware trigger on pin ADTRG,
integrated the three possible edge triggers into the subsystem
and created buffer management for data retrieval
Signed-off-by: Eugen Hristev <eugen.hristev at microchip.com>
---
drivers/iio/adc/at91-sama5d2_adc.c | 207 ++++++++++++++++++++++++++++++++++++-
1 file changed, 204 insertions(+), 3 deletions(-)
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index e10dca3..09a8c3d 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -23,8 +23,15 @@
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/wait.h>
+#include <linux/slab.h>
+
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
#include <linux/regulator/consumer.h>
/* Control Register */
@@ -132,6 +139,17 @@
#define AT91_SAMA5D2_PRESSR 0xbc
/* Trigger Register */
#define AT91_SAMA5D2_TRGR 0xc0
+/* Mask for TRGMOD field of TRGR register */
+#define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0)
+/* No trigger, only software trigger can start conversions */
+#define AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER 0
+/* Trigger Mode external trigger rising edge */
+#define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE 1
+/* Trigger Mode external trigger falling edge */
+#define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL 2
+/* Trigger Mode external trigger any edge */
+#define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY 3
+
/* Correction Select Register */
#define AT91_SAMA5D2_COSR 0xd0
/* Correction Value Register */
@@ -145,14 +163,20 @@
/* Version Register */
#define AT91_SAMA5D2_VERSION 0xfc
+#define AT91_SAMA5D2_HW_TRIG_CNT 3
+#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
+#define AT91_SAMA5D2_DIFF_CHAN_CNT 6
+
#define AT91_SAMA5D2_CHAN_SINGLE(num, addr) \
{ \
.type = IIO_VOLTAGE, \
.channel = num, \
.address = addr, \
+ .scan_index = num, \
.scan_type = { \
.sign = 'u', \
.realbits = 12, \
+ .storagebits = 16, \
}, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
@@ -168,9 +192,11 @@
.channel = num, \
.channel2 = num2, \
.address = addr, \
+ .scan_index = num + AT91_SAMA5D2_SINGLE_CHAN_CNT, \
.scan_type = { \
.sign = 's', \
.realbits = 12, \
+ .storagebits = 16, \
}, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
@@ -188,18 +214,26 @@ struct at91_adc_soc_info {
unsigned max_sample_rate;
};
+struct at91_adc_trigger {
+ char *name;
+ unsigned int trgmod_value;
+};
+
struct at91_adc_state {
void __iomem *base;
int irq;
struct clk *per_clk;
struct regulator *reg;
struct regulator *vref;
+ u16 *buffer;
int vref_uv;
const struct iio_chan_spec *chan;
bool conversion_done;
u32 conversion_value;
struct at91_adc_soc_info soc_info;
wait_queue_head_t wq_data_available;
+ struct iio_trigger **trig;
+ const struct at91_adc_trigger *trigger_list;
/*
* lock to prevent concurrent 'single conversion' requests through
* sysfs.
@@ -207,6 +241,21 @@ struct at91_adc_state {
struct mutex lock;
};
+static const struct at91_adc_trigger at91_adc_trigger_list[] = {
+ {
+ .name = "external-rising",
+ .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE,
+ },
+ {
+ .name = "external-falling",
+ .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL,
+ },
+ {
+ .name = "external-any",
+ .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY,
+ },
+};
+
static const struct iio_chan_spec at91_adc_channels[] = {
AT91_SAMA5D2_CHAN_SINGLE(0, 0x50),
AT91_SAMA5D2_CHAN_SINGLE(1, 0x54),
@@ -226,8 +275,141 @@ static const struct iio_chan_spec at91_adc_channels[] = {
AT91_SAMA5D2_CHAN_DIFF(6, 7, 0x68),
AT91_SAMA5D2_CHAN_DIFF(8, 9, 0x70),
AT91_SAMA5D2_CHAN_DIFF(10, 11, 0x78),
+ IIO_CHAN_SOFT_TIMESTAMP(AT91_SAMA5D2_SINGLE_CHAN_CNT
+ + AT91_SAMA5D2_DIFF_CHAN_CNT + 1),
};
+static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
+{
+ struct iio_dev *indio = iio_trigger_get_drvdata(trig);
+ struct at91_adc_state *st = iio_priv(indio);
+ u32 status = at91_adc_readl(st, AT91_SAMA5D2_TRGR);
+ u8 bit;
+ int i;
+
+ /* clear TRGMOD */
+ status &= ~AT91_SAMA5D2_TRGR_TRGMOD_MASK;
+
+ /* if we are disabling the trigger, it's enough to clear TRGMOD */
+ if (!state) {
+ at91_adc_writel(st, AT91_SAMA5D2_TRGR, status);
+ kfree(st->buffer);
+ return 0;
+ }
+
+ st->buffer = kmalloc(indio->scan_bytes, GFP_KERNEL);
+ if (!st->buffer)
+ return -ENOMEM;
+
+ for (i = 0; i < AT91_SAMA5D2_HW_TRIG_CNT; i++) {
+ if (!strstr(trig->name, st->trigger_list[i].name)) {
+ status |= st->trigger_list[i].trgmod_value;
+ break;
+ }
+ }
+
+ /* setup hw trigger */
+ at91_adc_writel(st, AT91_SAMA5D2_TRGR, status);
+
+ for_each_set_bit(bit, indio->active_scan_mask, indio->num_channels) {
+ struct iio_chan_spec const *chan = indio->channels + bit;
+
+ at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel));
+ at91_adc_writel(st, AT91_SAMA5D2_IER, BIT(chan->channel));
+ }
+
+ return 0;
+}
+
+static const struct iio_trigger_ops at91_adc_trigger_ops = {
+ .owner = THIS_MODULE,
+ .set_trigger_state = &at91_adc_configure_trigger,
+};
+
+static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *indio,
+ char *trigger_name)
+{
+ struct iio_trigger *trig;
+ int ret;
+
+ trig = devm_iio_trigger_alloc(&indio->dev, "%s-dev%d-%s", indio->name,
+ indio->id, trigger_name);
+ if (!trig)
+ return NULL;
+
+ trig->dev.parent = indio->dev.parent;
+ iio_trigger_set_drvdata(trig, indio);
+ trig->ops = &at91_adc_trigger_ops;
+
+ ret = devm_iio_trigger_register(&indio->dev, trig);
+
+ if (ret)
+ return NULL;
+
+ return trig;
+}
+
+static int at91_adc_trigger_init(struct iio_dev *indio)
+{
+ struct at91_adc_state *st = iio_priv(indio);
+ int i;
+
+ st->trig = devm_kzalloc(&indio->dev,
+ AT91_SAMA5D2_HW_TRIG_CNT * sizeof(*st->trig),
+ GFP_KERNEL);
+
+ if (!st->trig) {
+ dev_err(&indio->dev, "could not allocate trig list memory\n");
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < AT91_SAMA5D2_HW_TRIG_CNT; i++) {
+ st->trig[i] = at91_adc_allocate_trigger(indio,
+ st->trigger_list[i].name);
+ if (!st->trig[i]) {
+ dev_err(&indio->dev,
+ "could not allocate trigger %d\n", i);
+ return -ENOMEM;
+ }
+ }
+
+ return 0;
+}
+
+static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio = pf->indio_dev;
+ struct at91_adc_state *st = iio_priv(indio);
+ int i = 0;
+ u8 bit;
+
+ for_each_set_bit(bit, indio->active_scan_mask, indio->num_channels) {
+ struct iio_chan_spec const *chan = indio->channels + bit;
+
+ st->buffer[i] = at91_adc_readl(st, chan->address);
+ i++;
+ }
+
+ iio_push_to_buffers_with_timestamp(indio, st->buffer, pf->timestamp);
+
+ iio_trigger_notify_done(indio->trig);
+
+ /* Needed to ACK the DRDY interruption */
+ at91_adc_readl(st, AT91_SAMA5D2_LCDR);
+
+ enable_irq(st->irq);
+
+ return IRQ_HANDLED;
+}
+
+static int at91_adc_buffer_init(struct iio_dev *indio)
+{
+ return devm_iio_triggered_buffer_setup(&indio->dev, indio,
+ &iio_pollfunc_store_time,
+ &at91_adc_trigger_handler, NULL);
+}
+
static unsigned at91_adc_startup_time(unsigned startup_time_min,
unsigned adc_clk_khz)
{
@@ -293,14 +475,19 @@ static irqreturn_t at91_adc_interrupt(int irq, void *private)
u32 status = at91_adc_readl(st, AT91_SAMA5D2_ISR);
u32 imr = at91_adc_readl(st, AT91_SAMA5D2_IMR);
- if (status & imr) {
+ if (!(status & imr))
+ return IRQ_NONE;
+
+ if (iio_buffer_enabled(indio)) {
+ disable_irq_nosync(irq);
+ iio_trigger_poll(indio->trig);
+ } else {
st->conversion_value = at91_adc_readl(st, st->chan->address);
st->conversion_done = true;
wake_up_interruptible(&st->wq_data_available);
- return IRQ_HANDLED;
}
- return IRQ_NONE;
+ return IRQ_HANDLED;
}
static int at91_adc_read_raw(struct iio_dev *indio_dev,
@@ -406,6 +593,8 @@ static int at91_adc_probe(struct platform_device *pdev)
st = iio_priv(indio_dev);
+ st->trigger_list = at91_adc_trigger_list;
+
ret = of_property_read_u32(pdev->dev.of_node,
"atmel,min-sample-rate-hz",
&st->soc_info.min_sample_rate);
@@ -499,6 +688,18 @@ static int at91_adc_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, indio_dev);
+ ret = at91_adc_buffer_init(indio_dev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "couldn't initialize the buffer.\n");
+ goto per_clk_disable_unprepare;
+ }
+
+ ret = at91_adc_trigger_init(indio_dev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "couldn't setup the triggers.\n");
+ goto per_clk_disable_unprepare;
+ }
+
ret = iio_device_register(indio_dev);
if (ret < 0)
goto per_clk_disable_unprepare;
--
2.7.4
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