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-rw-r--r--drivers/iio/accel/bmc150-accel-i2c.c12
-rw-r--r--drivers/iio/accel/da280.c31
-rw-r--r--drivers/iio/accel/kxsd9-i2c.c3
-rw-r--r--drivers/iio/accel/mma8452.c20
-rw-r--r--drivers/iio/accel/st_accel_core.c5
-rw-r--r--drivers/iio/adc/Kconfig3
-rw-r--r--drivers/iio/adc/aspeed_adc.c25
-rw-r--r--drivers/iio/adc/at91-sama5d2_adc.c456
-rw-r--r--drivers/iio/adc/at91_adc.c4
-rw-r--r--drivers/iio/adc/axp288_adc.c20
-rw-r--r--drivers/iio/adc/hx711.c134
-rw-r--r--drivers/iio/adc/ina2xx-adc.c317
-rw-r--r--drivers/iio/adc/meson_saradc.c60
-rw-r--r--drivers/iio/adc/qcom-vadc-common.c4
-rw-r--r--drivers/iio/adc/stm32-adc-core.c14
-rw-r--r--drivers/iio/adc/stm32-adc-core.h14
-rw-r--r--drivers/iio/adc/stm32-adc.c199
-rw-r--r--drivers/iio/adc/ti_am335x_adc.c2
-rw-r--r--drivers/iio/chemical/ccs811.c13
-rw-r--r--drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c2
-rw-r--r--drivers/iio/common/ssp_sensors/ssp.h2
-rw-r--r--drivers/iio/common/ssp_sensors/ssp_dev.c2
-rw-r--r--drivers/iio/common/ssp_sensors/ssp_spi.c5
-rw-r--r--drivers/iio/counter/stm32-lptimer-cnt.c2
-rw-r--r--drivers/iio/dac/mcp4725.c2
-rw-r--r--drivers/iio/dac/stm32-dac-core.c14
-rw-r--r--drivers/iio/dac/stm32-dac-core.h15
-rw-r--r--drivers/iio/dac/stm32-dac.c15
-rw-r--r--drivers/iio/dummy/iio_dummy_evgen.c2
-rw-r--r--drivers/iio/gyro/adis16136.c15
-rw-r--r--drivers/iio/gyro/bmg160_core.c1
-rw-r--r--drivers/iio/health/max30102.c308
-rw-r--r--drivers/iio/humidity/hts221.h3
-rw-r--r--drivers/iio/humidity/hts221_core.c18
-rw-r--r--drivers/iio/humidity/hts221_i2c.c18
-rw-r--r--drivers/iio/humidity/hts221_spi.c18
-rw-r--r--drivers/iio/imu/adis16480.c28
-rw-r--r--drivers/iio/imu/inv_mpu6050/inv_mpu_acpi.c3
-rw-r--r--drivers/iio/imu/st_lsm6dsx/Kconfig2
-rw-r--r--drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h39
-rw-r--r--drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c107
-rw-r--r--drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c115
-rw-r--r--drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i2c.c55
-rw-r--r--drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_spi.c70
-rw-r--r--drivers/iio/industrialio-buffer.c15
-rw-r--r--drivers/iio/industrialio-core.c1
-rw-r--r--drivers/iio/light/Kconfig34
-rw-r--r--drivers/iio/light/Makefile4
-rw-r--r--drivers/iio/light/cros_ec_light_prox.c2
-rw-r--r--drivers/iio/light/st_uvis25.h37
-rw-r--r--drivers/iio/light/st_uvis25_core.c359
-rw-r--r--drivers/iio/light/st_uvis25_i2c.c69
-rw-r--r--drivers/iio/light/st_uvis25_spi.c68
-rw-r--r--drivers/iio/light/zopt2201.c568
-rw-r--r--drivers/iio/magnetometer/ak8975.c1
-rw-r--r--drivers/iio/pressure/bmp280-core.c203
-rw-r--r--drivers/iio/proximity/sx9500.c1
-rw-r--r--drivers/iio/trigger/stm32-lptimer-trigger.c3
-rw-r--r--drivers/iio/trigger/stm32-timer-trigger.c2
59 files changed, 2756 insertions, 808 deletions
diff --git a/drivers/iio/accel/bmc150-accel-i2c.c b/drivers/iio/accel/bmc150-accel-i2c.c
index f85014fbaa12..8ffc308d5fd0 100644
--- a/drivers/iio/accel/bmc150-accel-i2c.c
+++ b/drivers/iio/accel/bmc150-accel-i2c.c
@@ -81,9 +81,21 @@ static const struct i2c_device_id bmc150_accel_id[] = {
MODULE_DEVICE_TABLE(i2c, bmc150_accel_id);
+static const struct of_device_id bmc150_accel_of_match[] = {
+ { .compatible = "bosch,bmc150_accel" },
+ { .compatible = "bosch,bmi055_accel" },
+ { .compatible = "bosch,bma255" },
+ { .compatible = "bosch,bma250e" },
+ { .compatible = "bosch,bma222e" },
+ { .compatible = "bosch,bma280" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, bmc150_accel_of_match);
+
static struct i2c_driver bmc150_accel_driver = {
.driver = {
.name = "bmc150_accel_i2c",
+ .of_match_table = bmc150_accel_of_match,
.acpi_match_table = ACPI_PTR(bmc150_accel_acpi_match),
.pm = &bmc150_accel_pm_ops,
},
diff --git a/drivers/iio/accel/da280.c b/drivers/iio/accel/da280.c
index 6c214783241c..d4b555203427 100644
--- a/drivers/iio/accel/da280.c
+++ b/drivers/iio/accel/da280.c
@@ -11,6 +11,7 @@
#include <linux/module.h>
#include <linux/i2c.h>
+#include <linux/acpi.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/byteorder/generic.h>
@@ -25,7 +26,7 @@
#define DA280_MODE_ENABLE 0x1e
#define DA280_MODE_DISABLE 0x9e
-enum { da226, da280 };
+enum da280_chipset { da226, da280 };
/*
* a value of + or -4096 corresponds to + or - 1G
@@ -91,12 +92,24 @@ static const struct iio_info da280_info = {
.read_raw = da280_read_raw,
};
+static enum da280_chipset da280_match_acpi_device(struct device *dev)
+{
+ const struct acpi_device_id *id;
+
+ id = acpi_match_device(dev->driver->acpi_match_table, dev);
+ if (!id)
+ return -EINVAL;
+
+ return (enum da280_chipset) id->driver_data;
+}
+
static int da280_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct iio_dev *indio_dev;
struct da280_data *data;
+ enum da280_chipset chip;
ret = i2c_smbus_read_byte_data(client, DA280_REG_CHIP_ID);
if (ret != DA280_CHIP_ID)
@@ -114,7 +127,14 @@ static int da280_probe(struct i2c_client *client,
indio_dev->info = &da280_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = da280_channels;
- if (id->driver_data == da226) {
+
+ if (ACPI_HANDLE(&client->dev)) {
+ chip = da280_match_acpi_device(&client->dev);
+ } else {
+ chip = id->driver_data;
+ }
+
+ if (chip == da226) {
indio_dev->name = "da226";
indio_dev->num_channels = 2;
} else {
@@ -158,6 +178,12 @@ static int da280_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(da280_pm_ops, da280_suspend, da280_resume);
+static const struct acpi_device_id da280_acpi_match[] = {
+ {"MIRAACC", da280},
+ {},
+};
+MODULE_DEVICE_TABLE(acpi, da280_acpi_match);
+
static const struct i2c_device_id da280_i2c_id[] = {
{ "da226", da226 },
{ "da280", da280 },
@@ -168,6 +194,7 @@ MODULE_DEVICE_TABLE(i2c, da280_i2c_id);
static struct i2c_driver da280_driver = {
.driver = {
.name = "da280",
+ .acpi_match_table = ACPI_PTR(da280_acpi_match),
.pm = &da280_pm_ops,
},
.probe = da280_probe,
diff --git a/drivers/iio/accel/kxsd9-i2c.c b/drivers/iio/accel/kxsd9-i2c.c
index 98fbb628d5bd..38411e1c155b 100644
--- a/drivers/iio/accel/kxsd9-i2c.c
+++ b/drivers/iio/accel/kxsd9-i2c.c
@@ -63,3 +63,6 @@ static struct i2c_driver kxsd9_i2c_driver = {
.id_table = kxsd9_i2c_id,
};
module_i2c_driver(kxsd9_i2c_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("KXSD9 accelerometer I2C interface");
diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
index bfd4bc806fc2..7a2da7f9d4dc 100644
--- a/drivers/iio/accel/mma8452.c
+++ b/drivers/iio/accel/mma8452.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* mma8452.c - Support for following Freescale / NXP 3-axis accelerometers:
*
@@ -13,9 +14,6 @@
* Copyright 2015 Martin Kepplinger <martink@posteo.de>
* Copyright 2014 Peter Meerwald <pmeerw@pmeerw.net>
*
- * This file is subject to the terms and conditions of version 2 of
- * the GNU General Public License. See the file COPYING in the main
- * directory of this archive for more details.
*
* TODO: orientation events
*/
@@ -135,7 +133,7 @@ struct mma8452_event_regs {
u8 ev_count;
};
-static const struct mma8452_event_regs ev_regs_accel_falling = {
+static const struct mma8452_event_regs ff_mt_ev_regs = {
.ev_cfg = MMA8452_FF_MT_CFG,
.ev_cfg_ele = MMA8452_FF_MT_CFG_ELE,
.ev_cfg_chan_shift = MMA8452_FF_MT_CHAN_SHIFT,
@@ -145,7 +143,7 @@ static const struct mma8452_event_regs ev_regs_accel_falling = {
.ev_count = MMA8452_FF_MT_COUNT
};
-static const struct mma8452_event_regs ev_regs_accel_rising = {
+static const struct mma8452_event_regs trans_ev_regs = {
.ev_cfg = MMA8452_TRANSIENT_CFG,
.ev_cfg_ele = MMA8452_TRANSIENT_CFG_ELE,
.ev_cfg_chan_shift = MMA8452_TRANSIENT_CHAN_SHIFT,
@@ -284,7 +282,7 @@ static const int mma8452_samp_freq[8][2] = {
};
/* Datasheet table: step time "Relationship with the ODR" (sample frequency) */
-static const unsigned int mma8452_transient_time_step_us[4][8] = {
+static const unsigned int mma8452_time_step_us[4][8] = {
{ 1250, 2500, 5000, 10000, 20000, 20000, 20000, 20000 }, /* normal */
{ 1250, 2500, 5000, 10000, 20000, 80000, 80000, 80000 }, /* l p l n */
{ 1250, 2500, 2500, 2500, 2500, 2500, 2500, 2500 }, /* high res*/
@@ -777,12 +775,12 @@ static int mma8452_get_event_regs(struct mma8452_data *data,
& MMA8452_INT_TRANS) &&
(data->chip_info->enabled_events
& MMA8452_INT_TRANS))
- *ev_reg = &ev_regs_accel_rising;
+ *ev_reg = &trans_ev_regs;
else
- *ev_reg = &ev_regs_accel_falling;
+ *ev_reg = &ff_mt_ev_regs;
return 0;
case IIO_EV_DIR_FALLING:
- *ev_reg = &ev_regs_accel_falling;
+ *ev_reg = &ff_mt_ev_regs;
return 0;
default:
return -EINVAL;
@@ -826,7 +824,7 @@ static int mma8452_read_event_value(struct iio_dev *indio_dev,
if (power_mode < 0)
return power_mode;
- us = ret * mma8452_transient_time_step_us[power_mode][
+ us = ret * mma8452_time_step_us[power_mode][
mma8452_get_odr_index(data)];
*val = us / USEC_PER_SEC;
*val2 = us % USEC_PER_SEC;
@@ -883,7 +881,7 @@ static int mma8452_write_event_value(struct iio_dev *indio_dev,
return ret;
steps = (val * USEC_PER_SEC + val2) /
- mma8452_transient_time_step_us[ret][
+ mma8452_time_step_us[ret][
mma8452_get_odr_index(data)];
if (steps < 0 || steps > 0xff)
diff --git a/drivers/iio/accel/st_accel_core.c b/drivers/iio/accel/st_accel_core.c
index 460aa58e0159..6fe995cf16a6 100644
--- a/drivers/iio/accel/st_accel_core.c
+++ b/drivers/iio/accel/st_accel_core.c
@@ -920,8 +920,6 @@ static const struct iio_trigger_ops st_accel_trigger_ops = {
int st_accel_common_probe(struct iio_dev *indio_dev)
{
struct st_sensor_data *adata = iio_priv(indio_dev);
- struct st_sensors_platform_data *pdata =
- (struct st_sensors_platform_data *)adata->dev->platform_data;
int irq = adata->get_irq_data_ready(indio_dev);
int err;
@@ -948,9 +946,6 @@ int st_accel_common_probe(struct iio_dev *indio_dev)
&adata->sensor_settings->fs.fs_avl[0];
adata->odr = adata->sensor_settings->odr.odr_avl[0].hz;
- if (!pdata)
- pdata = (struct st_sensors_platform_data *)&default_accel_pdata;
-
err = st_sensors_init_sensor(indio_dev, adata->dev->platform_data);
if (err < 0)
goto st_accel_power_off;
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 39e3b345a6c8..72bc2b71765a 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -158,6 +158,7 @@ config AT91_SAMA5D2_ADC
tristate "Atmel AT91 SAMA5D2 ADC"
depends on ARCH_AT91 || COMPILE_TEST
depends on HAS_IOMEM
+ depends on HAS_DMA
select IIO_TRIGGERED_BUFFER
help
Say yes here to build support for Atmel SAMA5D2 ADC which is
@@ -318,6 +319,8 @@ config HI8435
config HX711
tristate "AVIA HX711 ADC for weight cells"
depends on GPIOLIB
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
help
If you say yes here you get support for AVIA HX711 ADC which is used
for weigh cells
diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index 8a958d5f1905..327a49ba1991 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -17,6 +17,7 @@
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
+#include <linux/reset.h>
#include <linux/spinlock.h>
#include <linux/types.h>
@@ -53,11 +54,12 @@ struct aspeed_adc_model_data {
};
struct aspeed_adc_data {
- struct device *dev;
- void __iomem *base;
- spinlock_t clk_lock;
- struct clk_hw *clk_prescaler;
- struct clk_hw *clk_scaler;
+ struct device *dev;
+ void __iomem *base;
+ spinlock_t clk_lock;
+ struct clk_hw *clk_prescaler;
+ struct clk_hw *clk_scaler;
+ struct reset_control *rst;
};
#define ASPEED_CHAN(_idx, _data_reg_addr) { \
@@ -217,6 +219,15 @@ static int aspeed_adc_probe(struct platform_device *pdev)
goto scaler_error;
}
+ data->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+ if (IS_ERR(data->rst)) {
+ dev_err(&pdev->dev,
+ "invalid or missing reset controller device tree entry");
+ ret = PTR_ERR(data->rst);
+ goto reset_error;
+ }
+ reset_control_deassert(data->rst);
+
model_data = of_device_get_match_data(&pdev->dev);
if (model_data->wait_init_sequence) {
@@ -263,9 +274,10 @@ iio_register_error:
writel(ASPEED_OPERATION_MODE_POWER_DOWN,
data->base + ASPEED_REG_ENGINE_CONTROL);
clk_disable_unprepare(data->clk_scaler->clk);
+reset_error:
+ reset_control_assert(data->rst);
clk_enable_error:
clk_hw_unregister_divider(data->clk_scaler);
-
scaler_error:
clk_hw_unregister_divider(data->clk_prescaler);
return ret;
@@ -280,6 +292,7 @@ static int aspeed_adc_remove(struct platform_device *pdev)
writel(ASPEED_OPERATION_MODE_POWER_DOWN,
data->base + ASPEED_REG_ENGINE_CONTROL);
clk_disable_unprepare(data->clk_scaler->clk);
+ reset_control_assert(data->rst);
clk_hw_unregister_divider(data->clk_scaler);
clk_hw_unregister_divider(data->clk_prescaler);
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index 755a493c2a2c..4eff8351ce29 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -16,6 +16,8 @@
#include <linux/bitops.h>
#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
@@ -100,6 +102,8 @@
#define AT91_SAMA5D2_LCDR 0x20
/* Interrupt Enable Register */
#define AT91_SAMA5D2_IER 0x24
+/* Interrupt Enable Register - general overrun error */
+#define AT91_SAMA5D2_IER_GOVRE BIT(25)
/* Interrupt Disable Register */
#define AT91_SAMA5D2_IDR 0x28
/* Interrupt Mask Register */
@@ -167,13 +171,19 @@
/*
* Maximum number of bytes to hold conversion from all channels
- * plus the timestamp
+ * without the timestamp.
*/
-#define AT91_BUFFER_MAX_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT + \
- AT91_SAMA5D2_DIFF_CHAN_CNT) * 2 + 8)
+#define AT91_BUFFER_MAX_CONVERSION_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT + \
+ AT91_SAMA5D2_DIFF_CHAN_CNT) * 2)
+
+/* This total must also include the timestamp */
+#define AT91_BUFFER_MAX_BYTES (AT91_BUFFER_MAX_CONVERSION_BYTES + 8)
#define AT91_BUFFER_MAX_HWORDS (AT91_BUFFER_MAX_BYTES / 2)
+#define AT91_HWFIFO_MAX_SIZE_STR "128"
+#define AT91_HWFIFO_MAX_SIZE 128
+
#define AT91_SAMA5D2_CHAN_SINGLE(num, addr) \
{ \
.type = IIO_VOLTAGE, \
@@ -228,6 +238,28 @@ struct at91_adc_trigger {
bool hw_trig;
};
+/**
+ * at91_adc_dma - at91-sama5d2 dma information struct
+ * @dma_chan: the dma channel acquired
+ * @rx_buf: dma coherent allocated area
+ * @rx_dma_buf: dma handler for the buffer
+ * @phys_addr: physical address of the ADC base register
+ * @buf_idx: index inside the dma buffer where reading was last done
+ * @rx_buf_sz: size of buffer used by DMA operation
+ * @watermark: number of conversions to copy before DMA triggers irq
+ * @dma_ts: hold the start timestamp of dma operation
+ */
+struct at91_adc_dma {
+ struct dma_chan *dma_chan;
+ u8 *rx_buf;
+ dma_addr_t rx_dma_buf;
+ phys_addr_t phys_addr;
+ int buf_idx;
+ int rx_buf_sz;
+ int watermark;
+ s64 dma_ts;
+};
+
struct at91_adc_state {
void __iomem *base;
int irq;
@@ -242,6 +274,7 @@ struct at91_adc_state {
u32 conversion_value;
struct at91_adc_soc_info soc_info;
wait_queue_head_t wq_data_available;
+ struct at91_adc_dma dma_st;
u16 buffer[AT91_BUFFER_MAX_HWORDS];
/*
* lock to prevent concurrent 'single conversion' requests through
@@ -322,11 +355,17 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
if (state) {
at91_adc_writel(st, AT91_SAMA5D2_CHER,
BIT(chan->channel));
- at91_adc_writel(st, AT91_SAMA5D2_IER,
- BIT(chan->channel));
+ /* enable irq only if not using DMA */
+ if (!st->dma_st.dma_chan) {
+ at91_adc_writel(st, AT91_SAMA5D2_IER,
+ BIT(chan->channel));
+ }
} else {
- at91_adc_writel(st, AT91_SAMA5D2_IDR,
- BIT(chan->channel));
+ /* disable irq only if not using DMA */
+ if (!st->dma_st.dma_chan) {
+ at91_adc_writel(st, AT91_SAMA5D2_IDR,
+ BIT(chan->channel));
+ }
at91_adc_writel(st, AT91_SAMA5D2_CHDR,
BIT(chan->channel));
}
@@ -340,6 +379,10 @@ static int at91_adc_reenable_trigger(struct iio_trigger *trig)
struct iio_dev *indio = iio_trigger_get_drvdata(trig);
struct at91_adc_state *st = iio_priv(indio);
+ /* if we are using DMA, we must not reenable irq after each trigger */
+ if (st->dma_st.dma_chan)
+ return 0;
+
enable_irq(st->irq);
/* Needed to ACK the DRDY interruption */
@@ -350,6 +393,153 @@ static int at91_adc_reenable_trigger(struct iio_trigger *trig)
static const struct iio_trigger_ops at91_adc_trigger_ops = {
.set_trigger_state = &at91_adc_configure_trigger,
.try_reenable = &at91_adc_reenable_trigger,
+ .validate_device = iio_trigger_validate_own_device,
+};
+
+static int at91_adc_dma_size_done(struct at91_adc_state *st)
+{
+ struct dma_tx_state state;
+ enum dma_status status;
+ int i, size;
+
+ status = dmaengine_tx_status(st->dma_st.dma_chan,
+ st->dma_st.dma_chan->cookie,
+ &state);
+ if (status != DMA_IN_PROGRESS)
+ return 0;
+
+ /* Transferred length is size in bytes from end of buffer */
+ i = st->dma_st.rx_buf_sz - state.residue;
+
+ /* Return available bytes */
+ if (i >= st->dma_st.buf_idx)
+ size = i - st->dma_st.buf_idx;
+ else
+ size = st->dma_st.rx_buf_sz + i - st->dma_st.buf_idx;
+ return size;
+}
+
+static void at91_dma_buffer_done(void *data)
+{
+ struct iio_dev *indio_dev = data;
+
+ iio_trigger_poll_chained(indio_dev->trig);
+}
+
+static int at91_adc_dma_start(struct iio_dev *indio_dev)
+{
+ struct at91_adc_state *st = iio_priv(indio_dev);
+ struct dma_async_tx_descriptor *desc;
+ dma_cookie_t cookie;
+ int ret;
+ u8 bit;
+
+ if (!st->dma_st.dma_chan)
+ return 0;
+
+ /* we start a new DMA, so set buffer index to start */
+ st->dma_st.buf_idx = 0;
+
+ /*
+ * compute buffer size w.r.t. watermark and enabled channels.
+ * scan_bytes is aligned so we need an exact size for DMA
+ */
+ st->dma_st.rx_buf_sz = 0;
+
+ for_each_set_bit(bit, indio_dev->active_scan_mask,
+ indio_dev->num_channels) {
+ struct iio_chan_spec const *chan = indio_dev->channels + bit;
+
+ st->dma_st.rx_buf_sz += chan->scan_type.storagebits / 8;
+ }
+ st->dma_st.rx_buf_sz *= st->dma_st.watermark;
+
+ /* Prepare a DMA cyclic transaction */
+ desc = dmaengine_prep_dma_cyclic(st->dma_st.dma_chan,
+ st->dma_st.rx_dma_buf,
+ st->dma_st.rx_buf_sz,
+ st->dma_st.rx_buf_sz / 2,
+ DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
+
+ if (!desc) {
+ dev_err(&indio_dev->dev, "cannot prepare DMA cyclic\n");
+ return -EBUSY;
+ }
+
+ desc->callback = at91_dma_buffer_done;
+ desc->callback_param = indio_dev;
+
+ cookie = dmaengine_submit(desc);
+ ret = dma_submit_error(cookie);
+ if (ret) {
+ dev_err(&indio_dev->dev, "cannot submit DMA cyclic\n");
+ dmaengine_terminate_async(st->dma_st.dma_chan);
+ return ret;
+ }
+
+ /* enable general overrun error signaling */
+ at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_GOVRE);
+ /* Issue pending DMA requests */
+ dma_async_issue_pending(st->dma_st.dma_chan);
+
+ /* consider current time as DMA start time for timestamps */
+ st->dma_st.dma_ts = iio_get_time_ns(indio_dev);
+
+ dev_dbg(&indio_dev->dev, "DMA cyclic started\n");
+
+ return 0;
+}
+
+static int at91_adc_buffer_postenable(struct iio_dev *indio_dev)
+{
+ int ret;
+
+ ret = at91_adc_dma_start(indio_dev);
+ if (ret) {
+ dev_err(&indio_dev->dev, "buffer postenable failed\n");
+ return ret;
+ }
+
+ return iio_triggered_buffer_postenable(indio_dev);
+}
+
+static int at91_adc_buffer_predisable(struct iio_dev *indio_dev)
+{
+ struct at91_adc_state *st = iio_priv(indio_dev);
+ int ret;
+ u8 bit;
+
+ ret = iio_triggered_buffer_predisable(indio_dev);
+ if (ret < 0)
+ dev_err(&indio_dev->dev, "buffer predisable failed\n");
+
+ if (!st->dma_st.dma_chan)
+ return ret;
+
+ /* if we are using DMA we must clear registers and end DMA */
+ dmaengine_terminate_sync(st->dma_st.dma_chan);
+
+ /*
+ * For each enabled channel we must read the last converted value
+ * to clear EOC status and not get a possible interrupt later.
+ * This value is being read by DMA from LCDR anyway
+ */
+ for_each_set_bit(bit, indio_dev->active_scan_mask,
+ indio_dev->num_channels) {
+ struct iio_chan_spec const *chan = indio_dev->channels + bit;
+
+ if (st->dma_st.dma_chan)
+ at91_adc_readl(st, chan->address);
+ }
+
+ /* read overflow register to clear possible overflow status */
+ at91_adc_readl(st, AT91_SAMA5D2_OVER);
+ return ret;
+}
+
+static const struct iio_buffer_setup_ops at91_buffer_setup_ops = {
+ .postenable = &at91_adc_buffer_postenable,