Re: [PATCH 2/2] iio: adc: Add Nuvoton MA35D1 EADC driver
From: Chi-Wen Weng
Date: Mon Jun 29 2026 - 03:41:28 EST
Hi David,
Thanks for the detailed review.
After looking at your comments and the other review feedback, I plan to
simplify v2 and limit the initial upstream driver to direct raw reads for
the external single-ended ADC channels.
In v2, I will drop the triggered buffer support, the device trigger and
the differential channel support for now. Buffered capture and
differential inputs can be added later as follow-up patches once the
scan sequencing, trigger model and differential pair constraints are
handled properly.
This also means that the scan buffer layout comments will no longer
apply to v2, since the triggered-buffer path will be removed from the
initial submission.
I will address the other driver comments in v2:
- drop the unused struct device pointer,
- remove the triggered-buffer and trigger-related Kconfig selects,
- switch the register access helpers to regmap,
- avoid forcing the external reference path unconditionally,
- add optional vref-supply handling,
- add IIO_CHAN_INFO_SCALE based on the selected reference source,
- use the internal reference when no vref-supply is provided,
- add a named macro for the sample-time field,
- drop the unused channel address field,
- drop datasheet_name from the initial driver,
- use device_for_each_child_node_scoped(),
- use devm_mutex_init(),
- keep only INDIO_DIRECT_MODE for the initial driver.
For the firmware-described channels, v2 will only accept the external
ADC input channels 0 to 7. The internal VBAT channel and differential
inputs will not be described or exposed by the initial driver.
Thanks,
Chi-Wen
David Lechner 於 2026/6/28 上午 04:52 寫道:
On 6/25/26 6:06 AM, Chi-Wen Weng wrote:
From: Chi-Wen Weng <cwweng@xxxxxxxxxxx>It looks like this is never used, so we can drop it.
Add an IIO driver for the Nuvoton MA35D1 Enhanced ADC controller.
The driver supports direct raw reads and triggered buffered capture. The
controller end-of-conversion interrupt is exposed as the device trigger
and is used to push samples into the IIO buffer.
Channels are described by firmware child nodes and can be configured as
single-ended or differential inputs. Since the differential enable bit is
global, mixed single-ended and differential buffered scans are rejected.
DMA support is intentionally not included in this initial upstream driver;
conversions are handled through the interrupt-driven path.
Signed-off-by: Chi-Wen Weng <cwweng@xxxxxxxxxxx>
---
drivers/iio/adc/Kconfig | 10 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ma35d1_eadc.c | 636 ++++++++++++++++++++++++++++++++++
3 files changed, 647 insertions(+)
create mode 100644 drivers/iio/adc/ma35d1_eadc.c
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 1c663c98c6c9..43409999a94b 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -981,6 +981,16 @@ config LTC2497
To compile this driver as a module, choose M here: the module will be
called ltc2497.
+config MA35D1_EADC
+ tristate "MA35D1 EADC driver"
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ help
+ Say yes here to build support for MA35D1 EADC.
+
+ To compile this driver as a module, choose M here: the module will be
+ called ma35d1.
+
config MAX1027
tristate "Maxim max1027 ADC driver"
depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 707dd708912f..7b9b38688223 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -85,6 +85,7 @@ obj-$(CONFIG_LTC2471) += ltc2471.o
obj-$(CONFIG_LTC2485) += ltc2485.o
obj-$(CONFIG_LTC2496) += ltc2496.o ltc2497-core.o
obj-$(CONFIG_LTC2497) += ltc2497.o ltc2497-core.o
+obj-$(CONFIG_MA35D1_EADC) += ma35d1_eadc.o
obj-$(CONFIG_MAX1027) += max1027.o
obj-$(CONFIG_MAX11100) += max11100.o
obj-$(CONFIG_MAX1118) += max1118.o
diff --git a/drivers/iio/adc/ma35d1_eadc.c b/drivers/iio/adc/ma35d1_eadc.c
new file mode 100644
index 000000000000..0c075126e139
--- /dev/null
+++ b/drivers/iio/adc/ma35d1_eadc.c
@@ -0,0 +1,636 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton MA35D1 EADC driver
+ *
+ * Copyright (c) 2026 Nuvoton Technology Corp.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/bitmap.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/property.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define MA35D1_EADC_DAT(n) (0x00 + (n) * 0x04)
+#define MA35D1_EADC_CTL 0x50
+#define MA35D1_EADC_SWTRG 0x54
+#define MA35D1_EADC_SCTL(n) (0x80 + (n) * 0x04)
+#define MA35D1_EADC_INTSRC0 0xd0
+#define MA35D1_EADC_STATUS2 0xf8
+#define MA35D1_EADC_SELSMP0 0x140
+#define MA35D1_EADC_REFADJCTL 0x150
+
+#define MA35D1_EADC_CTL_ADCEN BIT(0)
+#define MA35D1_EADC_CTL_ADCIEN0 BIT(2)
+#define MA35D1_EADC_CTL_DIFFEN BIT(8)
+
+#define MA35D1_EADC_SCTL_CHSEL_MASK GENMASK(3, 0)
+#define MA35D1_EADC_SCTL_TRGDLY_MASK GENMASK(15, 8)
+#define MA35D1_EADC_SCTL_TRGSEL_MASK GENMASK(21, 16)
+#define MA35D1_EADC_SCTL_TRGSEL_ADINT0 \
+ FIELD_PREP(MA35D1_EADC_SCTL_TRGSEL_MASK, 2)
+
+#define MA35D1_EADC_DAT_MASK GENMASK(11, 0)
+#define MA35D1_EADC_STATUS2_ADIF0 BIT(0)
+#define MA35D1_EADC_INTSRC0_ADINT0 BIT(0)
+#define MA35D1_EADC_REFADJCTL_EXT_VREF BIT(0)
+
+#define MA35D1_EADC_MAX_CHANNELS 9
+#define MA35D1_EADC_MAX_SAMPLE_MODULES 16
+#define MA35D1_EADC_CHAN_NAME_LEN 16
+#define MA35D1_EADC_TIMEOUT msecs_to_jiffies(1000)
+
+struct ma35d1_adc {
+ struct device *dev;
+ void __iomem *regs;Unless the hardware requires all channels to be read at once, we should
+ struct clk *clk;
+ struct completion completion;
+ /* Protects direct conversions against concurrent register access. */
+ struct mutex lock;
+ struct iio_trigger *trig;
+ unsigned int scan_chancnt;
+ bool scan_differential;
+ char chan_name[MA35D1_EADC_MAX_CHANNELS][MA35D1_EADC_CHAN_NAME_LEN];
+ struct {
+ u16 channels[MA35D1_EADC_MAX_SAMPLE_MODULES];
+ aligned_s64 timestamp;
+ } scan;
use this instead:
IIO_DECLARE_BUFFER_WITH_TS(u16, scan, MA35D1_EADC_MAX_SAMPLE_MODULES);
It means an array with enough room for MA35D1_EADC_MAX_SAMPLE_MODULES u16
data points plus an aligned timestamp, but doesn't specify where the
timestamp will be as it could be in a different place depending on how
many channels are read.
Also, this is only used in one function, so can just be stack-allocated
in that function (with ` = { };` to zero it) instead of allocating it here.
+};Why not use regmap?
+
+static inline u32 ma35d1_adc_read(struct ma35d1_adc *adc, u32 reg)
+{
+ return readl(adc->regs + reg);
+}
+
+static inline void ma35d1_adc_write(struct ma35d1_adc *adc, u32 reg, u32 val)
+{
+ writel(val, adc->regs + reg);
+}
+
+static void ma35d1_adc_rmw(struct ma35d1_adc *adc, u32 reg, u32 mask, u32 val)
+{
+ u32 tmp;
+
+ tmp = ma35d1_adc_read(adc, reg);
+ tmp &= ~mask;
+ tmp |= val;
+ ma35d1_adc_write(adc, reg, tmp);
+}
+As mentioned elsewhere, external reference doesn't make sense unless
+static void ma35d1_adc_set_diff(struct ma35d1_adc *adc, bool differential)
+{
+ ma35d1_adc_rmw(adc, MA35D1_EADC_CTL, MA35D1_EADC_CTL_DIFFEN,
+ differential ? MA35D1_EADC_CTL_DIFFEN : 0);
+}
+
+static void ma35d1_adc_config_sample(struct ma35d1_adc *adc,
+ unsigned int sample, unsigned int channel)
+{
+ u32 reg = MA35D1_EADC_SCTL(sample);
+
+ ma35d1_adc_rmw(adc, reg,
+ MA35D1_EADC_SCTL_CHSEL_MASK |
+ MA35D1_EADC_SCTL_TRGSEL_MASK,
+ FIELD_PREP(MA35D1_EADC_SCTL_CHSEL_MASK, channel) |
+ MA35D1_EADC_SCTL_TRGSEL_ADINT0);
+}
+
+static void ma35d1_adc_disable_irq(struct ma35d1_adc *adc)
+{
+ ma35d1_adc_rmw(adc, MA35D1_EADC_CTL, MA35D1_EADC_CTL_ADCIEN0, 0);
+}
+
+static void ma35d1_adc_hw_init(struct ma35d1_adc *adc)
+{
+ ma35d1_adc_disable_irq(adc);
+ ma35d1_adc_rmw(adc, MA35D1_EADC_CTL,
+ MA35D1_EADC_CTL_ADCEN, MA35D1_EADC_CTL_ADCEN);
+ ma35d1_adc_write(adc, MA35D1_EADC_STATUS2, MA35D1_EADC_STATUS2_ADIF0);
+ ma35d1_adc_rmw(adc, MA35D1_EADC_INTSRC0,
+ MA35D1_EADC_INTSRC0_ADINT0,
+ MA35D1_EADC_INTSRC0_ADINT0);
+ ma35d1_adc_rmw(adc, MA35D1_EADC_REFADJCTL,
+ MA35D1_EADC_REFADJCTL_EXT_VREF,
+ MA35D1_EADC_REFADJCTL_EXT_VREF);
we can get the reference voltage from it.
+ ma35d1_adc_rmw(adc, MA35D1_EADC_SELSMP0, GENMASK(1, 0), 3);ma35d1_adc_hw_init() doesn't enable the IRQ, so this seems a bit unbalanced.
+}
+
+static void ma35d1_adc_hw_disable(void *data)
+{
+ struct ma35d1_adc *adc = data;
+
+ ma35d1_adc_disable_irq(adc);
+ ma35d1_adc_rmw(adc, MA35D1_EADC_CTL, MA35D1_EADC_CTL_ADCEN, 0);Timestamp channel will never be set (it is handled differently), so we
+}
+
+static irqreturn_t ma35d1_adc_isr(int irq, void *data)
+{
+ struct iio_dev *indio_dev = data;
+ struct ma35d1_adc *adc = iio_priv(indio_dev);
+ u32 status;
+
+ status = ma35d1_adc_read(adc, MA35D1_EADC_STATUS2);
+ if (!(status & MA35D1_EADC_STATUS2_ADIF0))
+ return IRQ_NONE;
+
+ ma35d1_adc_write(adc, MA35D1_EADC_STATUS2, MA35D1_EADC_STATUS2_ADIF0);
+
+ if (iio_buffer_enabled(indio_dev)) {
+ ma35d1_adc_disable_irq(adc);
+ iio_trigger_poll(adc->trig);
+ } else {
+ complete(&adc->completion);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t ma35d1_adc_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct ma35d1_adc *adc = iio_priv(indio_dev);
+ int i;
+
+ for (i = 0; i < adc->scan_chancnt; i++)
+ adc->scan.channels[i] =
+ ma35d1_adc_read(adc, MA35D1_EADC_DAT(i)) &
+ MA35D1_EADC_DAT_MASK;
+
+ iio_push_to_buffers_with_timestamp(indio_dev, &adc->scan, pf->timestamp);
+ iio_trigger_notify_done(adc->trig);
+
+ ma35d1_adc_rmw(adc, MA35D1_EADC_CTL, MA35D1_EADC_CTL_ADCIEN0,
+ MA35D1_EADC_CTL_ADCIEN0);
+ ma35d1_adc_write(adc, MA35D1_EADC_SWTRG, 1);
+
+ return IRQ_HANDLED;
+}
+
+static int ma35d1_adc_read_conversion(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ int *val)
+{
+ struct ma35d1_adc *adc = iio_priv(indio_dev);
+ long timeout;
+
+ reinit_completion(&adc->completion);
+
+ ma35d1_adc_write(adc, MA35D1_EADC_STATUS2, MA35D1_EADC_STATUS2_ADIF0);
+ ma35d1_adc_rmw(adc, MA35D1_EADC_SCTL(0),
+ MA35D1_EADC_SCTL_CHSEL_MASK |
+ MA35D1_EADC_SCTL_TRGSEL_MASK,
+ FIELD_PREP(MA35D1_EADC_SCTL_CHSEL_MASK,
+ chan->channel));
+ ma35d1_adc_set_diff(adc, chan->differential);
+ ma35d1_adc_rmw(adc, MA35D1_EADC_CTL, MA35D1_EADC_CTL_ADCIEN0,
+ MA35D1_EADC_CTL_ADCIEN0);
+ ma35d1_adc_write(adc, MA35D1_EADC_SWTRG, 1);
+
+ timeout = wait_for_completion_interruptible_timeout(&adc->completion,
+ MA35D1_EADC_TIMEOUT);
+ ma35d1_adc_disable_irq(adc);
+
+ if (timeout < 0)
+ return timeout;
+ if (!timeout)
+ return -ETIMEDOUT;
+
+ *val = ma35d1_adc_read(adc, MA35D1_EADC_DAT(0)) & MA35D1_EADC_DAT_MASK;
+
+ return 0;
+}
+
+static int ma35d1_adc_read_raw(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ int *val, int *val2, long mask)
+{
+ struct ma35d1_adc *adc = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (!iio_device_claim_direct(indio_dev))
+ return -EBUSY;
+
+ mutex_lock(&adc->lock);
+ ret = ma35d1_adc_read_conversion(indio_dev, chan, val);
+ mutex_unlock(&adc->lock);
+
+ iio_device_release_direct(indio_dev);
+ if (ret)
+ return ret;
+
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ma35d1_adc_validate_scan(struct iio_dev *indio_dev,
+ const unsigned long *scan_mask)
+{
+ const struct iio_chan_spec *chan;
+ bool have_single = false;
+ bool have_diff = false;
+ unsigned int count = 0;
+ unsigned long bit;
+
+ for_each_set_bit(bit, scan_mask, indio_dev->masklength) {
+ chan = &indio_dev->channels[bit];
+
+ if (chan->type == IIO_TIMESTAMP)
+ continue;
don't need to check here.
+ count++;Same here.
+ if (chan->differential)
+ have_diff = true;
+ else
+ have_single = true;
+ }
+
+ if (!count || count > MA35D1_EADC_MAX_SAMPLE_MODULES)
+ return -EINVAL;
+
+ if (have_single && have_diff)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int ma35d1_adc_update_scan_mode(struct iio_dev *indio_dev,
+ const unsigned long *scan_mask)
+{
+ struct ma35d1_adc *adc = iio_priv(indio_dev);
+ const struct iio_chan_spec *chan;
+ unsigned int sample = 0;
+ unsigned long bit;
+ bool differential = false;
+ int ret;
+
+ ret = ma35d1_adc_validate_scan(indio_dev, scan_mask);
+ if (ret)
+ return ret;
+
+ for_each_set_bit(bit, scan_mask, indio_dev->masklength) {
+ chan = &indio_dev->channels[bit];
+ if (chan->type == IIO_TIMESTAMP)
+ continue;
+Should this even be possible because of ma35d1_adc_validate_scan()?
+ if (!sample)
+ differential = chan->differential;
+
+ ma35d1_adc_config_sample(adc, sample, chan->channel);
+ sample++;
+ }
+
+ adc->scan_chancnt = sample;
+ adc->scan_differential = differential;
+
+ return 0;
+}
+
+static int ma35d1_adc_buffer_postenable(struct iio_dev *indio_dev)
+{
+ struct ma35d1_adc *adc = iio_priv(indio_dev);
+ int i;
+
+ if (!adc->scan_chancnt)
+ return -EINVAL;
+How can we use the external V_REF without knowing what is connected to it?
+ ma35d1_adc_write(adc, MA35D1_EADC_STATUS2, MA35D1_EADC_STATUS2_ADIF0);
+ ma35d1_adc_rmw(adc, MA35D1_EADC_INTSRC0,
+ MA35D1_EADC_INTSRC0_ADINT0,
+ MA35D1_EADC_INTSRC0_ADINT0);
+ ma35d1_adc_rmw(adc, MA35D1_EADC_REFADJCTL,
+ MA35D1_EADC_REFADJCTL_EXT_VREF,
+ MA35D1_EADC_REFADJCTL_EXT_VREF);
I would expect this to use internal reference unless the devicetree specified
a vref-supply.
+ ma35d1_adc_rmw(adc, MA35D1_EADC_SELSMP0, GENMASK(1, 0), 3);There should be a macro to say what field GENMASK(1, 0) is.
+ ma35d1_adc_set_diff(adc, adc->scan_differential);Setting address is reduant if it is always going to be the same as channel.
+
+ for (i = 0; i < adc->scan_chancnt; i++)
+ ma35d1_adc_rmw(adc, MA35D1_EADC_SCTL(i),
+ MA35D1_EADC_SCTL_TRGDLY_MASK,
+ MA35D1_EADC_SCTL_TRGDLY_MASK);
+
+ ma35d1_adc_rmw(adc, MA35D1_EADC_CTL, MA35D1_EADC_CTL_ADCIEN0,
+ MA35D1_EADC_CTL_ADCIEN0);
+ ma35d1_adc_write(adc, MA35D1_EADC_SWTRG, 1);
+
+ return 0;
+}
+
+static int ma35d1_adc_buffer_predisable(struct iio_dev *indio_dev)
+{
+ struct ma35d1_adc *adc = iio_priv(indio_dev);
+ int i;
+
+ ma35d1_adc_disable_irq(adc);
+ for (i = 0; i < adc->scan_chancnt; i++)
+ ma35d1_adc_rmw(adc, MA35D1_EADC_SCTL(i),
+ MA35D1_EADC_SCTL_TRGSEL_MASK, 0);
+
+ return 0;
+}
+
+static const struct iio_buffer_setup_ops ma35d1_adc_buffer_ops = {
+ .postenable = ma35d1_adc_buffer_postenable,
+ .predisable = ma35d1_adc_buffer_predisable,
+};
+
+static const struct iio_info ma35d1_adc_info = {
+ .read_raw = ma35d1_adc_read_raw,
+ .update_scan_mode = ma35d1_adc_update_scan_mode,
+};
+
+static const struct iio_trigger_ops ma35d1_adc_trigger_ops = {
+ .validate_device = iio_trigger_validate_own_device,
+};
+
+static void ma35d1_adc_init_channel(struct ma35d1_adc *adc,
+ struct iio_chan_spec *chan, u32 vinp,
+ u32 vinn, int scan_index, bool differential)
+{
+ char *name = adc->chan_name[vinp];
+
+ chan->type = IIO_VOLTAGE;
+ chan->indexed = 1;
+ chan->channel = vinp;
+ chan->address = vinp;
We can just use channel directly instead. address doesn't appear to be
used anyway.
+ chan->scan_index = scan_index;This should also have IIO_CHAN_INFO_SCALE that is based on the reference source.
+ chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
+ chan->scan_type.sign = 'u';This field has a new name:
chan->scan_type.format = IIO_SCAN_FORMAT_UNSIGNED_INT;
+ chan->scan_type.realbits = 12;We usually don't use datasheet_name. It would make more sense to implement
+ chan->scan_type.storagebits = 16;
+ chan->scan_type.endianness = IIO_CPU;
+
+ if (differential) {
+ chan->differential = 1;
+ chan->channel2 = vinn;
+ snprintf(name, MA35D1_EADC_CHAN_NAME_LEN, "in%d-in%d", vinp,
+ vinn);
+ } else {
+ snprintf(name, MA35D1_EADC_CHAN_NAME_LEN, "in%d", vinp);
+ }
+
+ chan->datasheet_name = name;
labels and get the label from devicetree.
+}Can use device_for_each_child_node_scoped() here to avoid needing to put
+
+static int ma35d1_adc_parse_channels(struct iio_dev *indio_dev,
+ struct device *dev)
+{
+ struct ma35d1_adc *adc = iio_priv(indio_dev);
+ DECLARE_BITMAP(used_channels, MA35D1_EADC_MAX_CHANNELS);
+ struct fwnode_handle *child;
+ struct iio_chan_spec *channels;
+ int num_channels;
+ int scan_index = 0;
+ int ret;
+
+ bitmap_zero(used_channels, MA35D1_EADC_MAX_CHANNELS);
+
+ num_channels = device_get_child_node_count(dev);
+ if (!num_channels)
+ return dev_err_probe(dev, -ENODATA,
+ "no ADC channels configured\n");
+
+ if (num_channels > MA35D1_EADC_MAX_CHANNELS)
+ return dev_err_probe(dev, -EINVAL, "too many ADC channels\n");
+
+ channels = devm_kcalloc(dev, num_channels + 1, sizeof(*channels),
+ GFP_KERNEL);
+ if (!channels)
+ return -ENOMEM;
+
+ device_for_each_child_node(dev, child) {
handle on all return paths.
+ u32 diff[2];The macro already includes (struct iio_chan_spec) so we don't need it here.
+ u32 reg;
+ bool differential = false;
+
+ ret = fwnode_property_read_u32(child, "reg", ®);
+ if (ret) {
+ fwnode_handle_put(child);
+ return dev_err_probe(dev, ret,
+ "missing channel reg property\n");
+ }
+
+ if (reg >= MA35D1_EADC_MAX_CHANNELS) {
+ fwnode_handle_put(child);
+ return dev_err_probe(dev, -EINVAL,
+ "invalid ADC channel %u\n", reg);
+ }
+
+ if (test_and_set_bit(reg, used_channels)) {
+ fwnode_handle_put(child);
+ return dev_err_probe(dev, -EINVAL,
+ "duplicate ADC channel %u\n", reg);
+ }
+
+ if (fwnode_property_present(child, "diff-channels")) {
+ ret = fwnode_property_read_u32_array(child,
+ "diff-channels",
+ diff,
+ ARRAY_SIZE(diff));
+ if (ret) {
+ fwnode_handle_put(child);
+ return dev_err_probe(dev, ret,
+ "invalid diff-channels for channel %u\n",
+ reg);
+ }
+
+ if (diff[0] != reg ||
+ diff[1] >= MA35D1_EADC_MAX_CHANNELS ||
+ diff[0] == diff[1]) {
+ fwnode_handle_put(child);
+ return dev_err_probe(dev, -EINVAL,
+ "invalid differential ADC channel %u-%u\n",
+ diff[0], diff[1]);
+ }
+
+ if (test_and_set_bit(diff[1], used_channels)) {
+ fwnode_handle_put(child);
+ return dev_err_probe(dev, -EINVAL,
+ "ADC channel %u already used\n",
+ diff[1]);
+ }
+
+ differential = true;
+ }
+
+ ma35d1_adc_init_channel(adc, &channels[scan_index], reg,
+ differential ? diff[1] : 0,
+ scan_index, differential);
+ scan_index++;
+ }
+
+ channels[scan_index] = (struct iio_chan_spec)
+ IIO_CHAN_SOFT_TIMESTAMP(scan_index);devm_mutex_init()
+
+ indio_dev->channels = channels;
+ indio_dev->num_channels = scan_index + 1;
+ indio_dev->masklength = indio_dev->num_channels;
+
+ return 0;
+}
+
+static int ma35d1_adc_setup_trigger(struct iio_dev *indio_dev,
+ struct device *dev)
+{
+ struct ma35d1_adc *adc = iio_priv(indio_dev);
+ int ret;
+
+ adc->trig = devm_iio_trigger_alloc(dev, "%s-trigger", dev_name(dev));
+ if (!adc->trig)
+ return -ENOMEM;
+
+ adc->trig->ops = &ma35d1_adc_trigger_ops;
+ iio_trigger_set_drvdata(adc->trig, indio_dev);
+
+ ret = devm_iio_trigger_register(dev, adc->trig);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to register trigger\n");
+
+ ret = iio_trigger_set_immutable(indio_dev, adc->trig);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to set trigger\n");
+
+ return 0;
+}
+
+static int ma35d1_adc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct iio_dev *indio_dev;
+ struct ma35d1_adc *adc;
+ int irq;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
+ if (!indio_dev)
+ return -ENOMEM;
+ adc = iio_priv(indio_dev);
+ adc->dev = dev;
+ mutex_init(&adc->lock);
+ init_completion(&adc->completion);devm_iio_triggered_buffer_setup() sets the INDIO_BUFFER_TRIGGERED
+
+ adc->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(adc->regs))
+ return dev_err_probe(dev, PTR_ERR(adc->regs),
+ "failed to map registers\n");
+
+ adc->clk = devm_clk_get_enabled(dev, NULL);
+ if (IS_ERR(adc->clk))
+ return dev_err_probe(dev, PTR_ERR(adc->clk),
+ "failed to get and enable ADC clock\n");
+
+ indio_dev->name = "ma35d1-eadc";
+ indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_TRIGGERED;
flag, so we don't need it here.
+ indio_dev->info = &ma35d1_adc_info;
+
+ ret = ma35d1_adc_parse_channels(indio_dev, dev);
+ if (ret)
+ return ret;
+
+ ma35d1_adc_hw_init(adc);
+
+ ret = devm_add_action_or_reset(dev, ma35d1_adc_hw_disable, adc);
+ if (ret)
+ return ret;
+
+ ret = ma35d1_adc_setup_trigger(indio_dev, dev);
+ if (ret)
+ return ret;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ ret = devm_request_irq(dev, irq, ma35d1_adc_isr, 0, dev_name(dev),
+ indio_dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to request IRQ %d\n", irq);
+
+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+ iio_pollfunc_store_time,
+ ma35d1_adc_trigger_handler,
+ &ma35d1_adc_buffer_ops);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "failed to setup triggered buffer\n");
+
+ platform_set_drvdata(pdev, indio_dev);
+
+ ret = devm_iio_device_register(dev, indio_dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to register IIO device\n");
+
+ return 0;
+}
+
+static int ma35d1_adc_suspend(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ma35d1_adc *adc = iio_priv(indio_dev);
+
+ if (iio_buffer_enabled(indio_dev))
+ return -EBUSY;
+
+ ma35d1_adc_hw_disable(adc);
+ clk_disable_unprepare(adc->clk);
+
+ return 0;
+}
+
+static int ma35d1_adc_resume(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ma35d1_adc *adc = iio_priv(indio_dev);
+ int ret;
+
+ ret = clk_prepare_enable(adc->clk);
+ if (ret)
+ return ret;
+
+ ma35d1_adc_hw_init(adc);
+
+ return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(ma35d1_adc_pm_ops,
+ ma35d1_adc_suspend, ma35d1_adc_resume);
+
+static const struct of_device_id ma35d1_adc_of_match[] = {
+ { .compatible = "nuvoton,ma35d1-eadc" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ma35d1_adc_of_match);
+
+static struct platform_driver ma35d1_adc_driver = {
+ .probe = ma35d1_adc_probe,
+ .driver = {
+ .name = "ma35d1-eadc",
+ .of_match_table = ma35d1_adc_of_match,
+ .pm = pm_sleep_ptr(&ma35d1_adc_pm_ops),
+ },
+};
+module_platform_driver(ma35d1_adc_driver);
+
+MODULE_AUTHOR("Chi-Wen Weng <cwweng@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("Nuvoton MA35D1 EADC driver");
+MODULE_LICENSE("GPL");