iio: adc: vf610: Add IIO buffer support for Vybrid ADC
This patch adds support for IIO buffer to the Vybrid ADC driver.
IIO triggered buffer infrastructure along with iio sysfs trigger
is used to leverage continuous sampling support provided by the
ADC block.
Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index deea62c..2753118 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -361,6 +361,8 @@
config VF610_ADC
tristate "Freescale vf610 ADC driver"
depends on OF
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
help
Say yes here to support for Vybrid board analog-to-digital converter.
Since the IP is used for i.MX6SLX, the driver also support i.MX6SLX.
diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c
index 6bf4c20..635ccd8 100644
--- a/drivers/iio/adc/vf610_adc.c
+++ b/drivers/iio/adc/vf610_adc.c
@@ -34,8 +34,11 @@
#include <linux/err.h>
#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
#include <linux/iio/sysfs.h>
-#include <linux/iio/driver.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
/* This will be the driver name the kernel reports */
#define DRIVER_NAME "vf610-adc"
@@ -170,6 +173,7 @@
u32 sample_freq_avail[5];
struct completion completion;
+ u16 buffer[8];
};
static const u32 vf610_hw_avgs[] = { 1, 4, 8, 16, 32 };
@@ -505,12 +509,24 @@
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_SAMP_FREQ), \
.ext_info = vf610_ext_info, \
+ .scan_index = (_idx), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = 12, \
+ .storagebits = 16, \
+ }, \
}
#define VF610_ADC_TEMPERATURE_CHAN(_idx, _chan_type) { \
.type = (_chan_type), \
.channel = (_idx), \
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
+ .scan_index = (_idx), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = 12, \
+ .storagebits = 16, \
+ }, \
}
static const struct iio_chan_spec vf610_adc_iio_channels[] = {
@@ -531,6 +547,7 @@
VF610_ADC_CHAN(14, IIO_VOLTAGE),
VF610_ADC_CHAN(15, IIO_VOLTAGE),
VF610_ADC_TEMPERATURE_CHAN(26, IIO_TEMP),
+ IIO_CHAN_SOFT_TIMESTAMP(32),
/* sentinel */
};
@@ -559,13 +576,20 @@
static irqreturn_t vf610_adc_isr(int irq, void *dev_id)
{
- struct vf610_adc *info = (struct vf610_adc *)dev_id;
+ struct iio_dev *indio_dev = (struct iio_dev *)dev_id;
+ struct vf610_adc *info = iio_priv(indio_dev);
int coco;
coco = readl(info->regs + VF610_REG_ADC_HS);
if (coco & VF610_ADC_HS_COCO0) {
info->value = vf610_adc_read_data(info);
- complete(&info->completion);
+ if (iio_buffer_enabled(indio_dev)) {
+ info->buffer[0] = info->value;
+ iio_push_to_buffers_with_timestamp(indio_dev,
+ info->buffer, iio_get_time_ns());
+ iio_trigger_notify_done(indio_dev->trig);
+ } else
+ complete(&info->completion);
}
return IRQ_HANDLED;
@@ -613,8 +637,12 @@
case IIO_CHAN_INFO_RAW:
case IIO_CHAN_INFO_PROCESSED:
mutex_lock(&indio_dev->mlock);
- reinit_completion(&info->completion);
+ if (iio_buffer_enabled(indio_dev)) {
+ mutex_unlock(&indio_dev->mlock);
+ return -EBUSY;
+ }
+ reinit_completion(&info->completion);
hc_cfg = VF610_ADC_ADCHC(chan->channel);
hc_cfg |= VF610_ADC_AIEN;
writel(hc_cfg, info->regs + VF610_REG_ADC_HC0);
@@ -694,6 +722,60 @@
return -EINVAL;
}
+static int vf610_adc_buffer_postenable(struct iio_dev *indio_dev)
+{
+ struct vf610_adc *info = iio_priv(indio_dev);
+ unsigned int channel;
+ int ret;
+ int val;
+
+ ret = iio_triggered_buffer_postenable(indio_dev);
+ if (ret)
+ return ret;
+
+ val = readl(info->regs + VF610_REG_ADC_GC);
+ val |= VF610_ADC_ADCON;
+ writel(val, info->regs + VF610_REG_ADC_GC);
+
+ channel = find_first_bit(indio_dev->active_scan_mask,
+ indio_dev->masklength);
+
+ val = VF610_ADC_ADCHC(channel);
+ val |= VF610_ADC_AIEN;
+
+ writel(val, info->regs + VF610_REG_ADC_HC0);
+
+ return 0;
+}
+
+static int vf610_adc_buffer_predisable(struct iio_dev *indio_dev)
+{
+ struct vf610_adc *info = iio_priv(indio_dev);
+ unsigned int hc_cfg = 0;
+ int val, ret;
+
+ val = readl(info->regs + VF610_REG_ADC_GC);
+ val &= ~VF610_ADC_ADCON;
+ writel(val, info->regs + VF610_REG_ADC_GC);
+
+ hc_cfg |= VF610_ADC_CONV_DISABLE;
+ hc_cfg &= ~VF610_ADC_AIEN;
+
+ writel(hc_cfg, info->regs + VF610_REG_ADC_HC0);
+
+ ret = iio_triggered_buffer_predisable(indio_dev);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
+ .postenable = &vf610_adc_buffer_postenable,
+ .predisable = &vf610_adc_buffer_predisable,
+ .validate_scan_mask = &iio_validate_scan_mask_onehot,
+};
+
static int vf610_adc_reg_access(struct iio_dev *indio_dev,
unsigned reg, unsigned writeval,
unsigned *readval)
@@ -753,7 +835,7 @@
ret = devm_request_irq(info->dev, irq,
vf610_adc_isr, 0,
- dev_name(&pdev->dev), info);
+ dev_name(&pdev->dev), indio_dev);
if (ret < 0) {
dev_err(&pdev->dev, "failed requesting irq, irq = %d\n", irq);
return ret;
@@ -806,15 +888,23 @@
vf610_adc_cfg_init(info);
vf610_adc_hw_init(info);
+ ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
+ NULL, &iio_triggered_buffer_setup_ops);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Couldn't initialise the buffer\n");
+ goto error_iio_device_register;
+ }
+
ret = iio_device_register(indio_dev);
if (ret) {
dev_err(&pdev->dev, "Couldn't register the device.\n");
- goto error_iio_device_register;
+ goto error_adc_buffer_init;
}
return 0;
-
+error_adc_buffer_init:
+ iio_triggered_buffer_cleanup(indio_dev);
error_iio_device_register:
clk_disable_unprepare(info->clk);
error_adc_clk_enable:
@@ -829,6 +919,7 @@
struct vf610_adc *info = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
+ iio_triggered_buffer_cleanup(indio_dev);
regulator_disable(info->vref);
clk_disable_unprepare(info->clk);