This patch adds threshold events support for the MCP9600 device.
Based on fix:
3c324a40b7c3 iio: temperature: mcp9600: Fix temperature reading for negative values
Dimitri Fedrau (5):
iio: temperature: mcp9600: set channel2 member
iio: temperature: mcp9600: Share scale by all channels
iio: temperature: mcp9600: add newlines after if statements
iio: temperature: mcp9600: Fix line exceeding 80 columns
iio: temperature: mcp9600: add threshold events support
drivers/iio/temperature/mcp9600.c | 381 +++++++++++++++++++++++++++++-
1 file changed, 368 insertions(+), 13 deletions(-)
--
2.39.2
Set channel2 member of channel 0 to IIO_MOD_TEMP_OBJECT and set modified
member to 1.
Signed-off-by: Dimitri Fedrau <[email protected]>
---
drivers/iio/temperature/mcp9600.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/iio/temperature/mcp9600.c b/drivers/iio/temperature/mcp9600.c
index 7a3eef5d5e75..e277edb4ae4b 100644
--- a/drivers/iio/temperature/mcp9600.c
+++ b/drivers/iio/temperature/mcp9600.c
@@ -26,6 +26,8 @@ static const struct iio_chan_spec mcp9600_channels[] = {
{
.type = IIO_TEMP,
.address = MCP9600_HOT_JUNCTION,
+ .channel2 = IIO_MOD_TEMP_OBJECT,
+ .modified = 1,
.info_mask_separate =
BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
},
--
2.39.2
Move bit IIO_CHAN_INFO_SCALE from info_mask_separate to
info_mask_shared_by_all since temperature format is the same for all
channels.
Signed-off-by: Dimitri Fedrau <[email protected]>
---
drivers/iio/temperature/mcp9600.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/iio/temperature/mcp9600.c b/drivers/iio/temperature/mcp9600.c
index e277edb4ae4b..74e0782fb073 100644
--- a/drivers/iio/temperature/mcp9600.c
+++ b/drivers/iio/temperature/mcp9600.c
@@ -28,16 +28,16 @@ static const struct iio_chan_spec mcp9600_channels[] = {
.address = MCP9600_HOT_JUNCTION,
.channel2 = IIO_MOD_TEMP_OBJECT,
.modified = 1,
- .info_mask_separate =
- BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE),
},
{
.type = IIO_TEMP,
.address = MCP9600_COLD_JUNCTION,
.channel2 = IIO_MOD_TEMP_AMBIENT,
.modified = 1,
- .info_mask_separate =
- BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE),
},
};
--
2.39.2
Fix line exceeding 80 columns by introducing new variable "dev" and
apply it wherever possible in mcp9600_probe.
Signed-off-by: Dimitri Fedrau <[email protected]>
---
drivers/iio/temperature/mcp9600.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/temperature/mcp9600.c b/drivers/iio/temperature/mcp9600.c
index 4003bc8c83d3..cb1c1c1c361d 100644
--- a/drivers/iio/temperature/mcp9600.c
+++ b/drivers/iio/temperature/mcp9600.c
@@ -89,19 +89,20 @@ static const struct iio_info mcp9600_info = {
static int mcp9600_probe(struct i2c_client *client)
{
+ struct device *dev = &client->dev;
struct iio_dev *indio_dev;
struct mcp9600_data *data;
int ret;
ret = i2c_smbus_read_byte_data(client, MCP9600_DEVICE_ID);
if (ret < 0)
- return dev_err_probe(&client->dev, ret, "Failed to read device ID\n");
+ return dev_err_probe(dev, ret, "Failed to read device ID\n");
if (ret != MCP9600_DEVICE_ID_MCP9600)
- dev_warn(&client->dev, "Expected ID %x, got %x\n",
- MCP9600_DEVICE_ID_MCP9600, ret);
+ dev_warn(dev, "Expected ID %x, got %x\n",
+ MCP9600_DEVICE_ID_MCP9600, ret);
- indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
@@ -114,7 +115,7 @@ static int mcp9600_probe(struct i2c_client *client)
indio_dev->channels = mcp9600_channels;
indio_dev->num_channels = ARRAY_SIZE(mcp9600_channels);
- return devm_iio_device_register(&client->dev, indio_dev);
+ return devm_iio_device_register(dev, indio_dev);
}
static const struct i2c_device_id mcp9600_id[] = {
--
2.39.2
The device has four programmable temperature alert outputs which can be
used to monitor hot or cold-junction temperatures and detect falling and
rising temperatures. It supports up to 255 degree celsius programmable
hysteresis. Each alert can be individually configured by setting following
options in the associated alert configuration register:
- monitor hot or cold junction temperature
- monitor rising or falling temperature
- set comparator or interrupt mode
- set output polarity
- enable alert
This patch binds alert outputs to iio events:
- alert1: hot junction, rising temperature
- alert2: hot junction, falling temperature
- alert3: cold junction, rising temperature
- alert4: cold junction, falling temperature
All outputs are set in comparator mode and polarity depends on interrupt
configuration.
Signed-off-by: Dimitri Fedrau <[email protected]>
---
drivers/iio/temperature/mcp9600.c | 358 +++++++++++++++++++++++++++++-
1 file changed, 354 insertions(+), 4 deletions(-)
diff --git a/drivers/iio/temperature/mcp9600.c b/drivers/iio/temperature/mcp9600.c
index cb1c1c1c361d..f7e1b4e3253d 100644
--- a/drivers/iio/temperature/mcp9600.c
+++ b/drivers/iio/temperature/mcp9600.c
@@ -6,21 +6,80 @@
* Author: <[email protected]>
*/
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
+#include <linux/math.h>
+#include <linux/minmax.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/units.h>
+#include <linux/iio/events.h>
#include <linux/iio/iio.h>
/* MCP9600 registers */
-#define MCP9600_HOT_JUNCTION 0x0
-#define MCP9600_COLD_JUNCTION 0x2
-#define MCP9600_DEVICE_ID 0x20
+#define MCP9600_HOT_JUNCTION 0x0
+#define MCP9600_COLD_JUNCTION 0x2
+#define MCP9600_STATUS 0x4
+#define MCP9600_STATUS_ALERT(x) BIT(x)
+#define MCP9600_ALERT_CFG1 0x8
+#define MCP9600_ALERT_CFG(x) (MCP9600_ALERT_CFG1 + (x - 1))
+#define MCP9600_ALERT_CFG_ENABLE BIT(0)
+#define MCP9600_ALERT_CFG_ACTIVE_HIGH BIT(2)
+#define MCP9600_ALERT_CFG_FALLING BIT(3)
+#define MCP9600_ALERT_CFG_COLD_JUNCTION BIT(4)
+#define MCP9600_ALERT_HYSTERESIS1 0xc
+#define MCP9600_ALERT_HYSTERESIS(x) (MCP9600_ALERT_HYSTERESIS1 + (x - 1))
+#define MCP9600_ALERT_LIMIT1 0x10
+#define MCP9600_ALERT_LIMIT(x) (MCP9600_ALERT_LIMIT1 + (x - 1))
+
+#define MCP9600_DEVICE_ID 0x20
/* MCP9600 device id value */
-#define MCP9600_DEVICE_ID_MCP9600 0x40
+#define MCP9600_DEVICE_ID_MCP9600 0x40
+
+#define MCP9600_ALERT_COUNT 4
+
+#define MCP9600_MIN_TEMP_HOT_JUNCTION -200
+#define MCP9600_MAX_TEMP_HOT_JUNCTION 1800
+
+#define MCP9600_MIN_TEMP_COLD_JUNCTION -40
+#define MCP9600_MAX_TEMP_COLD_JUNCTION 125
+
+enum mcp9600_alert {
+ MCP9600_ALERT1,
+ MCP9600_ALERT2,
+ MCP9600_ALERT3,
+ MCP9600_ALERT4
+};
+
+static const char * const mcp9600_alert_name[MCP9600_ALERT_COUNT] = {
+ [MCP9600_ALERT1] = "alert1",
+ [MCP9600_ALERT2] = "alert2",
+ [MCP9600_ALERT3] = "alert3",
+ [MCP9600_ALERT4] = "alert4",
+};
+
+static const struct iio_event_spec mcp9600_events[] = {
+ {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_RISING,
+ .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
+ BIT(IIO_EV_INFO_VALUE) |
+ BIT(IIO_EV_INFO_HYSTERESIS),
+ },
+ {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_FALLING,
+ .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
+ BIT(IIO_EV_INFO_VALUE) |
+ BIT(IIO_EV_INFO_HYSTERESIS),
+ },
+};
static const struct iio_chan_spec mcp9600_channels[] = {
{
@@ -30,6 +89,8 @@ static const struct iio_chan_spec mcp9600_channels[] = {
.modified = 1,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE),
+ .event_spec = mcp9600_events,
+ .num_event_specs = ARRAY_SIZE(mcp9600_events),
},
{
.type = IIO_TEMP,
@@ -38,11 +99,15 @@ static const struct iio_chan_spec mcp9600_channels[] = {
.modified = 1,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE),
+ .event_spec = mcp9600_events,
+ .num_event_specs = ARRAY_SIZE(mcp9600_events),
},
};
struct mcp9600_data {
struct i2c_client *client;
+ struct mutex lock[MCP9600_ALERT_COUNT];
+ int irq[MCP9600_ALERT_COUNT];
};
static int mcp9600_read(struct mcp9600_data *data,
@@ -83,10 +148,292 @@ static int mcp9600_read_raw(struct iio_dev *indio_dev,
}
}
+static int mcp9600_get_alert_index(int channel2, enum iio_event_direction dir)
+{
+ switch (channel2) {
+ case IIO_MOD_TEMP_OBJECT:
+ if (dir == IIO_EV_DIR_RISING)
+ return MCP9600_ALERT1;
+ else
+ return MCP9600_ALERT2;
+ case IIO_MOD_TEMP_AMBIENT:
+ if (dir == IIO_EV_DIR_RISING)
+ return MCP9600_ALERT3;
+ else
+ return MCP9600_ALERT4;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int mcp9600_read_event_config(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir)
+{
+ struct mcp9600_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+ int i, ret;
+
+ i = mcp9600_get_alert_index(chan->channel2, dir);
+ if (i < 0)
+ return i;
+
+ ret = i2c_smbus_read_byte_data(client, MCP9600_ALERT_CFG(i + 1));
+ if (ret < 0)
+ return ret;
+
+ return (ret & MCP9600_ALERT_CFG_ENABLE);
+}
+
+static int mcp9600_write_event_config(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir,
+ int state)
+{
+ struct mcp9600_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+ int i, ret;
+
+ i = mcp9600_get_alert_index(chan->channel2, dir);
+ if (i < 0)
+ return i;
+
+ ret = i2c_smbus_read_byte_data(client, MCP9600_ALERT_CFG(i + 1));
+ if (ret < 0)
+ return ret;
+
+ if (state)
+ ret |= MCP9600_ALERT_CFG_ENABLE;
+ else
+ ret &= ~MCP9600_ALERT_CFG_ENABLE;
+
+ return i2c_smbus_write_byte_data(client, MCP9600_ALERT_CFG(i + 1), ret);
+}
+
+static int mcp9600_read_thresh(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir,
+ enum iio_event_info info, int *val, int *val2)
+{
+ struct mcp9600_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+ s32 ret;
+ int i;
+
+ i = mcp9600_get_alert_index(chan->channel2, dir);
+ if (i < 0)
+ return i;
+
+ guard(mutex)(&data->lock[i]);
+ ret = i2c_smbus_read_word_swapped(client, MCP9600_ALERT_LIMIT(i + 1));
+ if (ret < 0)
+ return ret;
+
+ /*
+ * Temperature is stored in two’s complement format in bits(15:2),
+ * LSB is 0.25 degree celsius.
+ */
+ *val = sign_extend32(ret, 15) >> 2;
+ *val2 = 4;
+ if (info == IIO_EV_INFO_VALUE)
+ return IIO_VAL_FRACTIONAL;
+
+ ret = i2c_smbus_read_byte_data(client, MCP9600_ALERT_HYSTERESIS(i + 1));
+ if (ret < 0)
+ return ret;
+
+ /*
+ * Hysteresis is stored as offset which is not signed, therefore we have
+ * to include directions when calculating the real hysteresis value.
+ */
+ if (dir == IIO_EV_DIR_RISING)
+ *val -= (*val2 * ret);
+ else
+ *val += (*val2 * ret);
+
+ return IIO_VAL_FRACTIONAL;
+}
+
+static int mcp9600_write_thresh(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir,
+ enum iio_event_info info, int val, int val2)
+{
+ struct mcp9600_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+ int s_val, s_thresh, i;
+ s16 thresh;
+ s32 ret;
+ u8 hyst;
+
+ /* Scale value to include decimal part into calculations */
+ s_val = (val < 0) ? ((val * (int)MICRO) - val2) :
+ ((val * (int)MICRO) + val2);
+
+ /* Hot junction temperature range is from –200 to 1800 degree celsius */
+ if (chan->channel2 == IIO_MOD_TEMP_OBJECT &&
+ (s_val < (MCP9600_MIN_TEMP_HOT_JUNCTION * (int)MICRO) ||
+ s_val > (MCP9600_MAX_TEMP_HOT_JUNCTION * (int)MICRO)))
+ return -EINVAL;
+
+ /* Cold junction temperature range is from –40 to 125 degree celsius */
+ if (chan->channel2 == IIO_MOD_TEMP_AMBIENT &&
+ (s_val < (MCP9600_MIN_TEMP_COLD_JUNCTION * (int)MICRO) ||
+ s_val > (MCP9600_MAX_TEMP_COLD_JUNCTION * (int)MICRO)))
+ return -EINVAL;
+
+ i = mcp9600_get_alert_index(chan->channel2, dir);
+ if (i < 0)
+ return i;
+
+ guard(mutex)(&data->lock[i]);
+ if (info == IIO_EV_INFO_VALUE) {
+ /*
+ * Shift length 4 bits = 2(15:2) + 2(0.25 LSB), temperature is
+ * stored in two’s complement format.
+ */
+ thresh = (s16)(s_val / (int)(MICRO >> 4));
+ return i2c_smbus_write_word_swapped(client,
+ MCP9600_ALERT_LIMIT(i + 1),
+ thresh);
+ }
+
+ /* Read out threshold, hysteresis is stored as offset */
+ ret = i2c_smbus_read_word_swapped(client, MCP9600_ALERT_LIMIT(i + 1));
+ if (ret < 0)
+ return ret;
+
+ /* Shift length 4 bits = 2(15:2) + 2(0.25 LSB), see above. */
+ s_thresh = sign_extend32(ret, 15) * (int)(MICRO >> 4);
+
+ /*
+ * Hysteresis is stored as offset, for rising temperatures, the
+ * hysteresis range is below the alert limit where, as for falling
+ * temperatures, the hysteresis range is above the alert limit.
+ */
+ hyst = min(255, abs(s_thresh - s_val) / MICRO);
+
+ return i2c_smbus_write_byte_data(client,
+ MCP9600_ALERT_HYSTERESIS(i + 1),
+ hyst);
+}
+
static const struct iio_info mcp9600_info = {
.read_raw = mcp9600_read_raw,
+ .read_event_config = mcp9600_read_event_config,
+ .write_event_config = mcp9600_write_event_config,
+ .read_event_value = mcp9600_read_thresh,
+ .write_event_value = mcp9600_write_thresh,
};
+static irqreturn_t mcp9600_alert_handler(int irq, void *private)
+{
+ struct iio_dev *indio_dev = private;
+ struct mcp9600_data *data = iio_priv(indio_dev);
+ enum iio_event_direction dir;
+ enum iio_modifier mod;
+ int i, ret;
+
+ for (i = 0; i < MCP9600_ALERT_COUNT; i++) {
+ if (data->irq[i] == irq)
+ break;
+ }
+
+ if (i >= MCP9600_ALERT_COUNT)
+ return IRQ_NONE;
+
+ ret = i2c_smbus_read_byte_data(data->client, MCP9600_STATUS);
+ if (ret < 0)
+ return IRQ_HANDLED;
+
+ switch (ret & MCP9600_STATUS_ALERT(i)) {
+ case 0:
+ return IRQ_NONE;
+ case MCP9600_STATUS_ALERT(MCP9600_ALERT1):
+ mod = IIO_MOD_TEMP_OBJECT;
+ dir = IIO_EV_DIR_RISING;
+ break;
+ case MCP9600_STATUS_ALERT(MCP9600_ALERT2):
+ mod = IIO_MOD_TEMP_OBJECT;
+ dir = IIO_EV_DIR_FALLING;
+ break;
+ case MCP9600_STATUS_ALERT(MCP9600_ALERT3):
+ mod = IIO_MOD_TEMP_AMBIENT;
+ dir = IIO_EV_DIR_RISING;
+ break;
+ case MCP9600_STATUS_ALERT(MCP9600_ALERT4):
+ mod = IIO_MOD_TEMP_AMBIENT;
+ dir = IIO_EV_DIR_FALLING;
+ break;
+ default:
+ return IRQ_HANDLED;
+ }
+
+ iio_push_event(indio_dev,
+ IIO_MOD_EVENT_CODE(IIO_TEMP, 0, mod,
+ IIO_EV_TYPE_THRESH, dir),
+ iio_get_time_ns(indio_dev));
+
+ return IRQ_HANDLED;
+}
+
+static int mcp9600_probe_alerts(struct iio_dev *indio_dev)
+{
+ struct mcp9600_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+ struct device *dev = &client->dev;
+ struct fwnode_handle *fwnode = dev_fwnode(dev);
+ unsigned int irq_type;
+ int ret, irq, i;
+ u8 val;
+
+ /*
+ * alert1: hot junction, rising temperature
+ * alert2: hot junction, falling temperature
+ * alert3: cold junction, rising temperature
+ * alert4: cold junction, falling temperature
+ */
+ for (i = 0; i < MCP9600_ALERT_COUNT; i++) {
+ data->irq[i] = 0;
+ mutex_init(&data->lock[i]);
+ irq = fwnode_irq_get_byname(fwnode, mcp9600_alert_name[i]);
+ if (irq <= 0)
+ continue;
+
+ val = 0;
+ irq_type = irq_get_trigger_type(irq);
+ if (irq_type == IRQ_TYPE_EDGE_RISING)
+ val |= MCP9600_ALERT_CFG_ACTIVE_HIGH;
+
+ if (i == MCP9600_ALERT2 || i == MCP9600_ALERT4)
+ val |= MCP9600_ALERT_CFG_FALLING;
+
+ if (i == MCP9600_ALERT3 || i == MCP9600_ALERT4)
+ val |= MCP9600_ALERT_CFG_COLD_JUNCTION;
+
+ ret = i2c_smbus_write_byte_data(client,
+ MCP9600_ALERT_CFG(i + 1),
+ val);
+ if (ret < 0)
+ return ret;
+
+ ret = devm_request_threaded_irq(dev, irq, NULL,
+ mcp9600_alert_handler,
+ IRQF_ONESHOT, "mcp9600",
+ indio_dev);
+ if (ret)
+ return ret;
+
+ data->irq[i] = irq;
+ }
+
+ return 0;
+}
+
static int mcp9600_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
@@ -109,6 +456,8 @@ static int mcp9600_probe(struct i2c_client *client)
data = iio_priv(indio_dev);
data->client = client;
+ mcp9600_probe_alerts(indio_dev);
+
indio_dev->info = &mcp9600_info;
indio_dev->name = "mcp9600";
indio_dev->modes = INDIO_DIRECT_MODE;
@@ -140,6 +489,7 @@ static struct i2c_driver mcp9600_driver = {
};
module_i2c_driver(mcp9600_driver);
+MODULE_AUTHOR("Dimitri Fedrau <[email protected]>");
MODULE_AUTHOR("Andrew Hepp <[email protected]>");
MODULE_DESCRIPTION("Microchip MCP9600 thermocouple EMF converter driver");
MODULE_LICENSE("GPL");
--
2.39.2
Add newlines after if statements following coding guide lines.
Signed-off-by: Dimitri Fedrau <[email protected]>
---
drivers/iio/temperature/mcp9600.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/iio/temperature/mcp9600.c b/drivers/iio/temperature/mcp9600.c
index 74e0782fb073..4003bc8c83d3 100644
--- a/drivers/iio/temperature/mcp9600.c
+++ b/drivers/iio/temperature/mcp9600.c
@@ -72,6 +72,7 @@ static int mcp9600_read_raw(struct iio_dev *indio_dev,
ret = mcp9600_read(data, chan, val);
if (ret)
return ret;
+
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 62;
@@ -95,6 +96,7 @@ static int mcp9600_probe(struct i2c_client *client)
ret = i2c_smbus_read_byte_data(client, MCP9600_DEVICE_ID);
if (ret < 0)
return dev_err_probe(&client->dev, ret, "Failed to read device ID\n");
+
if (ret != MCP9600_DEVICE_ID_MCP9600)
dev_warn(&client->dev, "Expected ID %x, got %x\n",
MCP9600_DEVICE_ID_MCP9600, ret);
--
2.39.2
Am Tue, Apr 30, 2024 at 01:11:02PM +0100 schrieb Jonathan Cameron:
> On Tue, 30 Apr 2024 14:05:31 +0200
> Dimitri Fedrau <[email protected]> wrote:
>
> > Set channel2 member of channel 0 to IIO_MOD_TEMP_OBJECT and set modified
> > member to 1.
> This an ABI change, so needs a strong argument + must be a fix
> rather than an improvement. So why does this need to change?
>
Hi Jonathan,
I don't know if it is an valid argument but when using tool "iio_info"
the temp_object wasn't displayed at all. After adding these two lines
the temp_object is displayed. Don't know if it is a problem with the
userspace tools.
iio_info version: 0.25 (git tag:b6028fde)
Libiio version: 0.25 (git tag: b6028fd) backends: local xml ip usb serial
Besides that it eases distinction between the two channels in the last
patch, but I think this argument is not strong enough. :)
Best regards,
Dimitri
>
> >
> > Signed-off-by: Dimitri Fedrau <[email protected]>
> > ---
> > drivers/iio/temperature/mcp9600.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/iio/temperature/mcp9600.c b/drivers/iio/temperature/mcp9600.c
> > index 7a3eef5d5e75..e277edb4ae4b 100644
> > --- a/drivers/iio/temperature/mcp9600.c
> > +++ b/drivers/iio/temperature/mcp9600.c
> > @@ -26,6 +26,8 @@ static const struct iio_chan_spec mcp9600_channels[] = {
> > {
> > .type = IIO_TEMP,
> > .address = MCP9600_HOT_JUNCTION,
> > + .channel2 = IIO_MOD_TEMP_OBJECT,
> > + .modified = 1,
> > .info_mask_separate =
> > BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> > },
>
Am Tue, Apr 30, 2024 at 01:09:34PM +0100 schrieb Jonathan Cameron:
> On Tue, 30 Apr 2024 14:05:32 +0200
> Dimitri Fedrau <[email protected]> wrote:
>
> > Move bit IIO_CHAN_INFO_SCALE from info_mask_separate to
> > info_mask_shared_by_all since temperature format is the same for all
> > channels.
> >
> > Signed-off-by: Dimitri Fedrau <[email protected]>
>
> Whilst this shouldn't be a problem for well behaved userspace,
> it is an ABI change so as a general rule we don't 'fix' cases like
> this once they have been in a kernel release.
>
> We may be break someone's hand crafted scripts :(
>
Ok, will remove the patch from the series.
Best regards,
Dimitri Fedrau
>
> > ---
> > drivers/iio/temperature/mcp9600.c | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/iio/temperature/mcp9600.c b/drivers/iio/temperature/mcp9600.c
> > index e277edb4ae4b..74e0782fb073 100644
> > --- a/drivers/iio/temperature/mcp9600.c
> > +++ b/drivers/iio/temperature/mcp9600.c
> > @@ -28,16 +28,16 @@ static const struct iio_chan_spec mcp9600_channels[] = {
> > .address = MCP9600_HOT_JUNCTION,
> > .channel2 = IIO_MOD_TEMP_OBJECT,
> > .modified = 1,
> > - .info_mask_separate =
> > - BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE),
> > },
> > {
> > .type = IIO_TEMP,
> > .address = MCP9600_COLD_JUNCTION,
> > .channel2 = IIO_MOD_TEMP_AMBIENT,
> > .modified = 1,
> > - .info_mask_separate =
> > - BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE),
> > },
> > };
> >
>
Hi Dimitri,
kernel test robot noticed the following build errors:
[auto build test ERROR on jic23-iio/togreg]
[also build test ERROR on linus/master v6.9-rc6 next-20240430]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Dimitri-Fedrau/iio-temperature-mcp9600-set-channel2-member/20240430-200914
base: https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
patch link: https://lore.kernel.org/r/20240430120535.46097-6-dima.fedrau%40gmail.com
patch subject: [PATCH 5/5] iio: temperature: mcp9600: add threshold events support
config: i386-buildonly-randconfig-005-20240501 (https://download.01.org/0day-ci/archive/20240501/[email protected]/config)
compiler: gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240501/[email protected]/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
All errors (new ones prefixed by >>):
drivers/iio/temperature/mcp9600.c: In function 'mcp9600_probe_alerts':
>> drivers/iio/temperature/mcp9600.c:407:28: error: implicit declaration of function 'irq_get_trigger_type' [-Werror=implicit-function-declaration]
407 | irq_type = irq_get_trigger_type(irq);
| ^~~~~~~~~~~~~~~~~~~~
>> drivers/iio/temperature/mcp9600.c:408:33: error: 'IRQ_TYPE_EDGE_RISING' undeclared (first use in this function)
408 | if (irq_type == IRQ_TYPE_EDGE_RISING)
| ^~~~~~~~~~~~~~~~~~~~
drivers/iio/temperature/mcp9600.c:408:33: note: each undeclared identifier is reported only once for each function it appears in
cc1: some warnings being treated as errors
vim +/irq_get_trigger_type +407 drivers/iio/temperature/mcp9600.c
382
383 static int mcp9600_probe_alerts(struct iio_dev *indio_dev)
384 {
385 struct mcp9600_data *data = iio_priv(indio_dev);
386 struct i2c_client *client = data->client;
387 struct device *dev = &client->dev;
388 struct fwnode_handle *fwnode = dev_fwnode(dev);
389 unsigned int irq_type;
390 int ret, irq, i;
391 u8 val;
392
393 /*
394 * alert1: hot junction, rising temperature
395 * alert2: hot junction, falling temperature
396 * alert3: cold junction, rising temperature
397 * alert4: cold junction, falling temperature
398 */
399 for (i = 0; i < MCP9600_ALERT_COUNT; i++) {
400 data->irq[i] = 0;
401 mutex_init(&data->lock[i]);
402 irq = fwnode_irq_get_byname(fwnode, mcp9600_alert_name[i]);
403 if (irq <= 0)
404 continue;
405
406 val = 0;
> 407 irq_type = irq_get_trigger_type(irq);
> 408 if (irq_type == IRQ_TYPE_EDGE_RISING)
409 val |= MCP9600_ALERT_CFG_ACTIVE_HIGH;
410
411 if (i == MCP9600_ALERT2 || i == MCP9600_ALERT4)
412 val |= MCP9600_ALERT_CFG_FALLING;
413
414 if (i == MCP9600_ALERT3 || i == MCP9600_ALERT4)
415 val |= MCP9600_ALERT_CFG_COLD_JUNCTION;
416
417 ret = i2c_smbus_write_byte_data(client,
418 MCP9600_ALERT_CFG(i + 1),
419 val);
420 if (ret < 0)
421 return ret;
422
423 ret = devm_request_threaded_irq(dev, irq, NULL,
424 mcp9600_alert_handler,
425 IRQF_ONESHOT, "mcp9600",
426 indio_dev);
427 if (ret)
428 return ret;
429
430 data->irq[i] = irq;
431 }
432
433 return 0;
434 }
435
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
On Tue, 30 Apr 2024 14:21:57 +0200
Dimitri Fedrau <[email protected]> wrote:
> Am Tue, Apr 30, 2024 at 01:11:02PM +0100 schrieb Jonathan Cameron:
> > On Tue, 30 Apr 2024 14:05:31 +0200
> > Dimitri Fedrau <[email protected]> wrote:
> >
> > > Set channel2 member of channel 0 to IIO_MOD_TEMP_OBJECT and set modified
> > > member to 1.
> > This an ABI change, so needs a strong argument + must be a fix
> > rather than an improvement. So why does this need to change?
> >
> Hi Jonathan,
>
> I don't know if it is an valid argument but when using tool "iio_info"
> the temp_object wasn't displayed at all. After adding these two lines
> the temp_object is displayed. Don't know if it is a problem with the
> userspace tools.
Just to check, it displayed not temperature channel for this?
If you could send the file listing of the appropriate
/sys/bus/iio/devices/iio\:deviceX/ directory that would be great.
It is possible the tools don't cope with a mixture of modified and unmodified
channels (without index). Whilst the ABI docs don't say you can't do this
it is a rather obscure corner case.
The maping from hotjunction to object isn't totally clear to me.
Mind you neither is the mapping from cold junction to ambient (that one is
a bit stronger as the datasheet tables assume
Cold Junction Temperature == Ambient Temperature.
Example of why I don't like this is object is no obvious if the hotjunction
is in a gas or liquid. The object defintion was I think added for infrared
temperature sensors where you get nothing meaningful without an object to
emit the infrared.
An alternative would be to provide an index for both channels. Also an ABI
change, but avoids the object / hot junction issue and I would assume works
fine with iio_info.
Jonathan
>
> iio_info version: 0.25 (git tag:b6028fde)
> Libiio version: 0.25 (git tag: b6028fd) backends: local xml ip usb serial
>
> Besides that it eases distinction between the two channels in the last
> patch, but I think this argument is not strong enough. :)
>
> Best regards,
> Dimitri
>
> >
> > >
> > > Signed-off-by: Dimitri Fedrau <[email protected]>
> > > ---
> > > drivers/iio/temperature/mcp9600.c | 2 ++
> > > 1 file changed, 2 insertions(+)
> > >
> > > diff --git a/drivers/iio/temperature/mcp9600.c b/drivers/iio/temperature/mcp9600.c
> > > index 7a3eef5d5e75..e277edb4ae4b 100644
> > > --- a/drivers/iio/temperature/mcp9600.c
> > > +++ b/drivers/iio/temperature/mcp9600.c
> > > @@ -26,6 +26,8 @@ static const struct iio_chan_spec mcp9600_channels[] = {
> > > {
> > > .type = IIO_TEMP,
> > > .address = MCP9600_HOT_JUNCTION,
> > > + .channel2 = IIO_MOD_TEMP_OBJECT,
> > > + .modified = 1,
> > > .info_mask_separate =
> > > BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> > > },
> >
>
On Tue, 30 Apr 2024 14:05:35 +0200
Dimitri Fedrau <[email protected]> wrote:
> The device has four programmable temperature alert outputs which can be
> used to monitor hot or cold-junction temperatures and detect falling and
> rising temperatures. It supports up to 255 degree celsius programmable
> hysteresis. Each alert can be individually configured by setting following
> options in the associated alert configuration register:
> - monitor hot or cold junction temperature
> - monitor rising or falling temperature
> - set comparator or interrupt mode
> - set output polarity
> - enable alert
>
> This patch binds alert outputs to iio events:
> - alert1: hot junction, rising temperature
> - alert2: hot junction, falling temperature
> - alert3: cold junction, rising temperature
> - alert4: cold junction, falling temperature
>
> All outputs are set in comparator mode and polarity depends on interrupt
> configuration.
>
> Signed-off-by: Dimitri Fedrau <[email protected]>
> ---
Various comments inline.
Jonathan
> drivers/iio/temperature/mcp9600.c | 358 +++++++++++++++++++++++++++++-
> 1 file changed, 354 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/iio/temperature/mcp9600.c b/drivers/iio/temperature/mcp9600.c
> index cb1c1c1c361d..f7e1b4e3253d 100644
> --- a/drivers/iio/temperature/mcp9600.c
> +++ b/drivers/iio/temperature/mcp9600.c
> @@ -6,21 +6,80 @@
> * Author: <[email protected]>
> */
>
> +#include <linux/bitfield.h>
> +#include <linux/bitops.h>
> #include <linux/err.h>
> #include <linux/i2c.h>
> #include <linux/init.h>
> +#include <linux/math.h>
> +#include <linux/minmax.h>
> #include <linux/mod_devicetable.h>
> #include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/units.h>
>
> +#include <linux/iio/events.h>
> #include <linux/iio/iio.h>
>
> /* MCP9600 registers */
> -#define MCP9600_HOT_JUNCTION 0x0
As below. Reformating in a precursor patch. I wouldn't necessarily bother
though as aligning defines is usually more effort than it is worth over time.
> -#define MCP9600_COLD_JUNCTION 0x2
> -#define MCP9600_DEVICE_ID 0x20
> +#define MCP9600_HOT_JUNCTION 0x0
> +#define MCP9600_COLD_JUNCTION 0x2
> +#define MCP9600_STATUS 0x4
> +#define MCP9600_STATUS_ALERT(x) BIT(x)
> +#define MCP9600_ALERT_CFG1 0x8
> +#define MCP9600_ALERT_CFG(x) (MCP9600_ALERT_CFG1 + (x - 1))
> +#define MCP9600_ALERT_CFG_ENABLE BIT(0)
> +#define MCP9600_ALERT_CFG_ACTIVE_HIGH BIT(2)
> +#define MCP9600_ALERT_CFG_FALLING BIT(3)
> +#define MCP9600_ALERT_CFG_COLD_JUNCTION BIT(4)
> +#define MCP9600_ALERT_HYSTERESIS1 0xc
> +#define MCP9600_ALERT_HYSTERESIS(x) (MCP9600_ALERT_HYSTERESIS1 + (x - 1))
> +#define MCP9600_ALERT_LIMIT1 0x10
> +#define MCP9600_ALERT_LIMIT(x) (MCP9600_ALERT_LIMIT1 + (x - 1))
> +
> +#define MCP9600_DEVICE_ID 0x20
>
> /* MCP9600 device id value */
> -#define MCP9600_DEVICE_ID_MCP9600 0x40
> +#define MCP9600_DEVICE_ID_MCP9600 0x40
If you want to reformatting existing lines, do it in a precursor patch - not
buried in here.
>
> struct mcp9600_data {
> struct i2c_client *client;
> + struct mutex lock[MCP9600_ALERT_COUNT];
All locks need documentation. What data is this protecting?
> + int irq[MCP9600_ALERT_COUNT];
> };
>
> static int mcp9600_read(struct mcp9600_data *data,
> @@ -83,10 +148,292 @@ static int mcp9600_read_raw(struct iio_dev *indio_dev,
> }
> }
>
> +static int mcp9600_get_alert_index(int channel2, enum iio_event_direction dir)
> +{
> + switch (channel2) {
> + case IIO_MOD_TEMP_OBJECT:
> + if (dir == IIO_EV_DIR_RISING)
> + return MCP9600_ALERT1;
> + else
> + return MCP9600_ALERT2;
> + case IIO_MOD_TEMP_AMBIENT:
> + if (dir == IIO_EV_DIR_RISING)
> + return MCP9600_ALERT3;
> + else
> + return MCP9600_ALERT4;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int mcp9600_read_event_config(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan,
> + enum iio_event_type type,
> + enum iio_event_direction dir)
> +{
> + struct mcp9600_data *data = iio_priv(indio_dev);
> + struct i2c_client *client = data->client;
> + int i, ret;
> +
> + i = mcp9600_get_alert_index(chan->channel2, dir);
> + if (i < 0)
> + return i;
> +
> + ret = i2c_smbus_read_byte_data(client, MCP9600_ALERT_CFG(i + 1));
> + if (ret < 0)
> + return ret;
> +
> + return (ret & MCP9600_ALERT_CFG_ENABLE);
FIELD_GET() even if it happens to be bit(0) as then we don't have to go
check that's the case.
> +}
> +
> +static int mcp9600_write_event_config(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan,
> + enum iio_event_type type,
> + enum iio_event_direction dir,
> + int state)
> +{
> + struct mcp9600_data *data = iio_priv(indio_dev);
> + struct i2c_client *client = data->client;
> + int i, ret;
> +
> + i = mcp9600_get_alert_index(chan->channel2, dir);
> + if (i < 0)
> + return i;
> +
> + ret = i2c_smbus_read_byte_data(client, MCP9600_ALERT_CFG(i + 1));
> + if (ret < 0)
> + return ret;
> +
> + if (state)
> + ret |= MCP9600_ALERT_CFG_ENABLE;
> + else
> + ret &= ~MCP9600_ALERT_CFG_ENABLE;
> +
> + return i2c_smbus_write_byte_data(client, MCP9600_ALERT_CFG(i + 1), ret);
A read modify write cycle like this normally needs some locking to ensure another
access didn't change the other bits in the register.
> +}
> +
> +static int mcp9600_read_thresh(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan,
> + enum iio_event_type type,
> + enum iio_event_direction dir,
> + enum iio_event_info info, int *val, int *val2)
> +{
> + struct mcp9600_data *data = iio_priv(indio_dev);
> + struct i2c_client *client = data->client;
> + s32 ret;
> + int i;
> +
> + i = mcp9600_get_alert_index(chan->channel2, dir);
> + if (i < 0)
> + return i;
> +
> + guard(mutex)(&data->lock[i]);
> + ret = i2c_smbus_read_word_swapped(client, MCP9600_ALERT_LIMIT(i + 1));
> + if (ret < 0)
> + return ret;
> +
> + /*
> + * Temperature is stored in two’s complement format in bits(15:2),
> + * LSB is 0.25 degree celsius.
> + */
> + *val = sign_extend32(ret, 15) >> 2;
Use sign_extend32(FIELD_GET(...), 13)
So which bits are extracted is obvious in the code.
> + *val2 = 4;
> + if (info == IIO_EV_INFO_VALUE)
> + return IIO_VAL_FRACTIONAL;
> +
> + ret = i2c_smbus_read_byte_data(client, MCP9600_ALERT_HYSTERESIS(i + 1));
> + if (ret < 0)
> + return ret;
> +
> + /*
> + * Hysteresis is stored as offset which is not signed, therefore we have
> + * to include directions when calculating the real hysteresis value.
> + */
> + if (dir == IIO_EV_DIR_RISING)
> + *val -= (*val2 * ret);
> + else
> + *val += (*val2 * ret);
I don't follow this maths. Hysteresis is an unsigned offset. Maybe some confusion
over the ABI?
> +
> + return IIO_VAL_FRACTIONAL;
> +}
> +
> +static int mcp9600_write_thresh(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan,
> + enum iio_event_type type,
> + enum iio_event_direction dir,
> + enum iio_event_info info, int val, int val2)
> +{
> + struct mcp9600_data *data = iio_priv(indio_dev);
> + struct i2c_client *client = data->client;
> + int s_val, s_thresh, i;
> + s16 thresh;
> + s32 ret;
> + u8 hyst;
> +
> + /* Scale value to include decimal part into calculations */
> + s_val = (val < 0) ? ((val * (int)MICRO) - val2) :
> + ((val * (int)MICRO) + val2);
> +
> + /* Hot junction temperature range is from –200 to 1800 degree celsius */
> + if (chan->channel2 == IIO_MOD_TEMP_OBJECT &&
> + (s_val < (MCP9600_MIN_TEMP_HOT_JUNCTION * (int)MICRO) ||
> + s_val > (MCP9600_MAX_TEMP_HOT_JUNCTION * (int)MICRO)))
Why the casts?
> + return -EINVAL;
> +
> + /* Cold junction temperature range is from –40 to 125 degree celsius */
> + if (chan->channel2 == IIO_MOD_TEMP_AMBIENT &&
> + (s_val < (MCP9600_MIN_TEMP_COLD_JUNCTION * (int)MICRO) ||
> + s_val > (MCP9600_MAX_TEMP_COLD_JUNCTION * (int)MICRO)))
> + return -EINVAL;
> +
> + i = mcp9600_get_alert_index(chan->channel2, dir);
> + if (i < 0)
> + return i;
> +
> + guard(mutex)(&data->lock[i]);
> + if (info == IIO_EV_INFO_VALUE) {
I would use a switch statement so it is obvious what each case is.
> + /*
> + * Shift length 4 bits = 2(15:2) + 2(0.25 LSB), temperature is
> + * stored in two’s complement format.
> + */
> + thresh = (s16)(s_val / (int)(MICRO >> 4));
> + return i2c_smbus_write_word_swapped(client,
> + MCP9600_ALERT_LIMIT(i + 1),
> + thresh);
> + }
> +
> + /* Read out threshold, hysteresis is stored as offset */
> + ret = i2c_smbus_read_word_swapped(client, MCP9600_ALERT_LIMIT(i + 1));
> + if (ret < 0)
> + return ret;
> +
> + /* Shift length 4 bits = 2(15:2) + 2(0.25 LSB), see above. */
> + s_thresh = sign_extend32(ret, 15) * (int)(MICRO >> 4);
> +
> + /*
> + * Hysteresis is stored as offset, for rising temperatures, the
> + * hysteresis range is below the alert limit where, as for falling
> + * temperatures, the hysteresis range is above the alert limit.
> + */
> + hyst = min(255, abs(s_thresh - s_val) / MICRO);
> +
> + return i2c_smbus_write_byte_data(client,
> + MCP9600_ALERT_HYSTERESIS(i + 1),
> + hyst);
> +}
> +
> static const struct iio_info mcp9600_info = {
> .read_raw = mcp9600_read_raw,
> + .read_event_config = mcp9600_read_event_config,
> + .write_event_config = mcp9600_write_event_config,
> + .read_event_value = mcp9600_read_thresh,
> + .write_event_value = mcp9600_write_thresh,
> };
>
> +static irqreturn_t mcp9600_alert_handler(int irq, void *private)
> +{
> + struct iio_dev *indio_dev = private;
> + struct mcp9600_data *data = iio_priv(indio_dev);
> + enum iio_event_direction dir;
> + enum iio_modifier mod;
> + int i, ret;
> +
> + for (i = 0; i < MCP9600_ALERT_COUNT; i++) {
> + if (data->irq[i] == irq)
This search for a match is a little messy. I'd be tempted
to wrap the generic handler in a per instance interrupt handler
(so have 4 functions) and thus move this matching to the place
where they are registered, not the interrupt handler.
There isn't a lot of shared code in here so you may be better
off just having 4 separate interrupt handler implementations.
> + break;
> + }
> +
> + if (i >= MCP9600_ALERT_COUNT)
> + return IRQ_NONE;
> +
> + ret = i2c_smbus_read_byte_data(data->client, MCP9600_STATUS);
> + if (ret < 0)
> + return IRQ_HANDLED;
> +
> + switch (ret & MCP9600_STATUS_ALERT(i)) {
> + case 0:
> + return IRQ_NONE;
> + case MCP9600_STATUS_ALERT(MCP9600_ALERT1):
> + mod = IIO_MOD_TEMP_OBJECT;
> + dir = IIO_EV_DIR_RISING;
> + break;
> + case MCP9600_STATUS_ALERT(MCP9600_ALERT2):
> + mod = IIO_MOD_TEMP_OBJECT;
> + dir = IIO_EV_DIR_FALLING;
> + break;
> + case MCP9600_STATUS_ALERT(MCP9600_ALERT3):
> + mod = IIO_MOD_TEMP_AMBIENT;
> + dir = IIO_EV_DIR_RISING;
> + break;
> + case MCP9600_STATUS_ALERT(MCP9600_ALERT4):
> + mod = IIO_MOD_TEMP_AMBIENT;
> + dir = IIO_EV_DIR_FALLING;
> + break;
> + default:
> + return IRQ_HANDLED;
> + }
> +
> + iio_push_event(indio_dev,
> + IIO_MOD_EVENT_CODE(IIO_TEMP, 0, mod,
> + IIO_EV_TYPE_THRESH, dir),
> + iio_get_time_ns(indio_dev));
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int mcp9600_probe_alerts(struct iio_dev *indio_dev)
> +{
> + struct mcp9600_data *data = iio_priv(indio_dev);
> + struct i2c_client *client = data->client;
> + struct device *dev = &client->dev;
> + struct fwnode_handle *fwnode = dev_fwnode(dev);
> + unsigned int irq_type;
> + int ret, irq, i;
> + u8 val;
> +
> + /*
> + * alert1: hot junction, rising temperature
> + * alert2: hot junction, falling temperature
> + * alert3: cold junction, rising temperature
> + * alert4: cold junction, falling temperature
> + */
> + for (i = 0; i < MCP9600_ALERT_COUNT; i++) {
> + data->irq[i] = 0;
All of data is zeroed already so this should not be needed.
> + mutex_init(&data->lock[i]);
Why per interrupt locks? Seems unlikely to be a big problem
to share one.
> + irq = fwnode_irq_get_byname(fwnode, mcp9600_alert_name[i]);
> + if (irq <= 0)
> + continue;
> +
> + val = 0;
> + irq_type = irq_get_trigger_type(irq);
> + if (irq_type == IRQ_TYPE_EDGE_RISING)
> + val |= MCP9600_ALERT_CFG_ACTIVE_HIGH;
> +
> + if (i == MCP9600_ALERT2 || i == MCP9600_ALERT4)
> + val |= MCP9600_ALERT_CFG_FALLING;
> +
> + if (i == MCP9600_ALERT3 || i == MCP9600_ALERT4)
> + val |= MCP9600_ALERT_CFG_COLD_JUNCTION;
> +
> + ret = i2c_smbus_write_byte_data(client,
> + MCP9600_ALERT_CFG(i + 1),
> + val);
> + if (ret < 0)
> + return ret;
> +
> + ret = devm_request_threaded_irq(dev, irq, NULL,
> + mcp9600_alert_handler,
> + IRQF_ONESHOT, "mcp9600",
> + indio_dev);
> + if (ret)
> + return ret;
> +
> + data->irq[i] = irq;
> + }
> +
> + return 0;
> +}
> +
> static int mcp9600_probe(struct i2c_client *client)
> {
> struct device *dev = &client->dev;
> @@ -109,6 +456,8 @@ static int mcp9600_probe(struct i2c_client *client)
> data = iio_priv(indio_dev);
> data->client = client;
>
> + mcp9600_probe_alerts(indio_dev);
Why no error check?
> +
> indio_dev->info = &mcp9600_info;
> indio_dev->name = "mcp9600";
> indio_dev->modes = INDIO_DIRECT_MODE;
> @@ -140,6 +489,7 @@ static struct i2c_driver mcp9600_driver = {
> };
> module_i2c_driver(mcp9600_driver);
>
> +MODULE_AUTHOR("Dimitri Fedrau <[email protected]>");
> MODULE_AUTHOR("Andrew Hepp <[email protected]>");
> MODULE_DESCRIPTION("Microchip MCP9600 thermocouple EMF converter driver");
> MODULE_LICENSE("GPL");
Am Sun, May 05, 2024 at 06:47:00PM +0100 schrieb Jonathan Cameron:
> On Tue, 30 Apr 2024 14:05:35 +0200
> Dimitri Fedrau <[email protected]> wrote:
>
> > The device has four programmable temperature alert outputs which can be
> > used to monitor hot or cold-junction temperatures and detect falling and
> > rising temperatures. It supports up to 255 degree celsius programmable
> > hysteresis. Each alert can be individually configured by setting following
> > options in the associated alert configuration register:
> > - monitor hot or cold junction temperature
> > - monitor rising or falling temperature
> > - set comparator or interrupt mode
> > - set output polarity
> > - enable alert
> >
> > This patch binds alert outputs to iio events:
> > - alert1: hot junction, rising temperature
> > - alert2: hot junction, falling temperature
> > - alert3: cold junction, rising temperature
> > - alert4: cold junction, falling temperature
> >
> > All outputs are set in comparator mode and polarity depends on interrupt
> > configuration.
> >
> > Signed-off-by: Dimitri Fedrau <[email protected]>
> > ---
> Various comments inline.
>
> Jonathan
>
> > drivers/iio/temperature/mcp9600.c | 358 +++++++++++++++++++++++++++++-
> > 1 file changed, 354 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/iio/temperature/mcp9600.c b/drivers/iio/temperature/mcp9600.c
> > index cb1c1c1c361d..f7e1b4e3253d 100644
> > --- a/drivers/iio/temperature/mcp9600.c
> > +++ b/drivers/iio/temperature/mcp9600.c
> > @@ -6,21 +6,80 @@
> > * Author: <[email protected]>
> > */
> >
> > +#include <linux/bitfield.h>
> > +#include <linux/bitops.h>
> > #include <linux/err.h>
> > #include <linux/i2c.h>
> > #include <linux/init.h>
> > +#include <linux/math.h>
> > +#include <linux/minmax.h>
> > #include <linux/mod_devicetable.h>
> > #include <linux/module.h>
> > +#include <linux/mutex.h>
> > +#include <linux/units.h>
> >
> > +#include <linux/iio/events.h>
> > #include <linux/iio/iio.h>
> >
> > /* MCP9600 registers */
> > -#define MCP9600_HOT_JUNCTION 0x0
>
> As below. Reformating in a precursor patch. I wouldn't necessarily bother
> though as aligning defines is usually more effort than it is worth over time.
>
Ok, will skip the aligning.
> > -#define MCP9600_COLD_JUNCTION 0x2
> > -#define MCP9600_DEVICE_ID 0x20
> > +#define MCP9600_HOT_JUNCTION 0x0
> > +#define MCP9600_COLD_JUNCTION 0x2
> > +#define MCP9600_STATUS 0x4
> > +#define MCP9600_STATUS_ALERT(x) BIT(x)
> > +#define MCP9600_ALERT_CFG1 0x8
> > +#define MCP9600_ALERT_CFG(x) (MCP9600_ALERT_CFG1 + (x - 1))
> > +#define MCP9600_ALERT_CFG_ENABLE BIT(0)
> > +#define MCP9600_ALERT_CFG_ACTIVE_HIGH BIT(2)
> > +#define MCP9600_ALERT_CFG_FALLING BIT(3)
> > +#define MCP9600_ALERT_CFG_COLD_JUNCTION BIT(4)
> > +#define MCP9600_ALERT_HYSTERESIS1 0xc
> > +#define MCP9600_ALERT_HYSTERESIS(x) (MCP9600_ALERT_HYSTERESIS1 + (x - 1))
> > +#define MCP9600_ALERT_LIMIT1 0x10
> > +#define MCP9600_ALERT_LIMIT(x) (MCP9600_ALERT_LIMIT1 + (x - 1))
> > +
> > +#define MCP9600_DEVICE_ID 0x20
> >
> > /* MCP9600 device id value */
> > -#define MCP9600_DEVICE_ID_MCP9600 0x40
> > +#define MCP9600_DEVICE_ID_MCP9600 0x40
>
> If you want to reformatting existing lines, do it in a precursor patch - not
> buried in here.
>
Ok, will skip the aligning.
> >
> > struct mcp9600_data {
> > struct i2c_client *client;
> > + struct mutex lock[MCP9600_ALERT_COUNT];
>
> All locks need documentation. What data is this protecting?
>
It protects hysteresis values, since these are represented as offsets
from thresholds. To read/write hysteresis values we need to read first
the corresponding threshold value. This can lead to race conditions, as
both can be accessed concurrently via sysfs.
> > + int irq[MCP9600_ALERT_COUNT];
> > };
> >
> > static int mcp9600_read(struct mcp9600_data *data,
> > @@ -83,10 +148,292 @@ static int mcp9600_read_raw(struct iio_dev *indio_dev,
> > }
> > }
> >
> > +static int mcp9600_get_alert_index(int channel2, enum iio_event_direction dir)
> > +{
> > + switch (channel2) {
> > + case IIO_MOD_TEMP_OBJECT:
> > + if (dir == IIO_EV_DIR_RISING)
> > + return MCP9600_ALERT1;
> > + else
> > + return MCP9600_ALERT2;
> > + case IIO_MOD_TEMP_AMBIENT:
> > + if (dir == IIO_EV_DIR_RISING)
> > + return MCP9600_ALERT3;
> > + else
> > + return MCP9600_ALERT4;
> > + default:
> > + return -EINVAL;
> > + }
> > +}
> > +
> > +static int mcp9600_read_event_config(struct iio_dev *indio_dev,
> > + const struct iio_chan_spec *chan,
> > + enum iio_event_type type,
> > + enum iio_event_direction dir)
> > +{
> > + struct mcp9600_data *data = iio_priv(indio_dev);
> > + struct i2c_client *client = data->client;
> > + int i, ret;
> > +
> > + i = mcp9600_get_alert_index(chan->channel2, dir);
> > + if (i < 0)
> > + return i;
> > +
> > + ret = i2c_smbus_read_byte_data(client, MCP9600_ALERT_CFG(i + 1));
> > + if (ret < 0)
> > + return ret;
> > +
> > + return (ret & MCP9600_ALERT_CFG_ENABLE);
>
> FIELD_GET() even if it happens to be bit(0) as then we don't have to go
> check that's the case.
>
Ok.
> > +}
> > +
> > +static int mcp9600_write_event_config(struct iio_dev *indio_dev,
> > + const struct iio_chan_spec *chan,
> > + enum iio_event_type type,
> > + enum iio_event_direction dir,
> > + int state)
> > +{
> > + struct mcp9600_data *data = iio_priv(indio_dev);
> > + struct i2c_client *client = data->client;
> > + int i, ret;
> > +
> > + i = mcp9600_get_alert_index(chan->channel2, dir);
> > + if (i < 0)
> > + return i;
> > +
> > + ret = i2c_smbus_read_byte_data(client, MCP9600_ALERT_CFG(i + 1));
> > + if (ret < 0)
> > + return ret;
> > +
> > + if (state)
> > + ret |= MCP9600_ALERT_CFG_ENABLE;
> > + else
> > + ret &= ~MCP9600_ALERT_CFG_ENABLE;
> > +
> > + return i2c_smbus_write_byte_data(client, MCP9600_ALERT_CFG(i + 1), ret);
>
> A read modify write cycle like this normally needs some locking to ensure another
> access didn't change the other bits in the register.
>
Each alert has it's own configuration register. All bits except the
enable bit are set during probe and there is no need besides the enable
bit to set them.
>
> > +}
> > +
> > +static int mcp9600_read_thresh(struct iio_dev *indio_dev,
> > + const struct iio_chan_spec *chan,
> > + enum iio_event_type type,
> > + enum iio_event_direction dir,
> > + enum iio_event_info info, int *val, int *val2)
> > +{
> > + struct mcp9600_data *data = iio_priv(indio_dev);
> > + struct i2c_client *client = data->client;
> > + s32 ret;
> > + int i;
> > +
> > + i = mcp9600_get_alert_index(chan->channel2, dir);
> > + if (i < 0)
> > + return i;
> > +
> > + guard(mutex)(&data->lock[i]);
> > + ret = i2c_smbus_read_word_swapped(client, MCP9600_ALERT_LIMIT(i + 1));
> > + if (ret < 0)
> > + return ret;
> > +
> > + /*
> > + * Temperature is stored in two’s complement format in bits(15:2),
> > + * LSB is 0.25 degree celsius.
> > + */
> > + *val = sign_extend32(ret, 15) >> 2;
> Use sign_extend32(FIELD_GET(...), 13)
> So which bits are extracted is obvious in the code.
>
Ok.
> > + *val2 = 4;
> > + if (info == IIO_EV_INFO_VALUE)
> > + return IIO_VAL_FRACTIONAL;
> > +
> > + ret = i2c_smbus_read_byte_data(client, MCP9600_ALERT_HYSTERESIS(i + 1));
> > + if (ret < 0)
> > + return ret;
> > +
> > + /*
> > + * Hysteresis is stored as offset which is not signed, therefore we have
> > + * to include directions when calculating the real hysteresis value.
> > + */
> > + if (dir == IIO_EV_DIR_RISING)
> > + *val -= (*val2 * ret);
> > + else
> > + *val += (*val2 * ret);
>
> I don't follow this maths. Hysteresis is an unsigned offset. Maybe some confusion
> over the ABI?
>
The alert hysteresis range is from 0 to 255 degree celsius. The
direction bit in the alert configuration register defines whether the
value is below or above the corresponding threshold. The offset here is
the threshold itself. I will improve the comment.
> > +
> > + return IIO_VAL_FRACTIONAL;
> > +}
> > +
> > +static int mcp9600_write_thresh(struct iio_dev *indio_dev,
> > + const struct iio_chan_spec *chan,
> > + enum iio_event_type type,
> > + enum iio_event_direction dir,
> > + enum iio_event_info info, int val, int val2)
> > +{
> > + struct mcp9600_data *data = iio_priv(indio_dev);
> > + struct i2c_client *client = data->client;
> > + int s_val, s_thresh, i;
> > + s16 thresh;
> > + s32 ret;
> > + u8 hyst;
> > +
> > + /* Scale value to include decimal part into calculations */
> > + s_val = (val < 0) ? ((val * (int)MICRO) - val2) :
> > + ((val * (int)MICRO) + val2);
> > +
> > + /* Hot junction temperature range is from –200 to 1800 degree celsius */
> > + if (chan->channel2 == IIO_MOD_TEMP_OBJECT &&
> > + (s_val < (MCP9600_MIN_TEMP_HOT_JUNCTION * (int)MICRO) ||
> > + s_val > (MCP9600_MAX_TEMP_HOT_JUNCTION * (int)MICRO)))
>
> Why the casts?
>
Missed to remove them. Will fix it in the next version of the patch.
> > + return -EINVAL;
> > +
> > + /* Cold junction temperature range is from –40 to 125 degree celsius */
> > + if (chan->channel2 == IIO_MOD_TEMP_AMBIENT &&
> > + (s_val < (MCP9600_MIN_TEMP_COLD_JUNCTION * (int)MICRO) ||
> > + s_val > (MCP9600_MAX_TEMP_COLD_JUNCTION * (int)MICRO)))
> > + return -EINVAL;
> > +
> > + i = mcp9600_get_alert_index(chan->channel2, dir);
> > + if (i < 0)
> > + return i;
> > +
> > + guard(mutex)(&data->lock[i]);
> > + if (info == IIO_EV_INFO_VALUE) {
>
> I would use a switch statement so it is obvious what each case is.
>
Ok.
> > + /*
> > + * Shift length 4 bits = 2(15:2) + 2(0.25 LSB), temperature is
> > + * stored in two’s complement format.
> > + */
> > + thresh = (s16)(s_val / (int)(MICRO >> 4));
> > + return i2c_smbus_write_word_swapped(client,
> > + MCP9600_ALERT_LIMIT(i + 1),
> > + thresh);
> > + }
> > +
> > + /* Read out threshold, hysteresis is stored as offset */
> > + ret = i2c_smbus_read_word_swapped(client, MCP9600_ALERT_LIMIT(i + 1));
> > + if (ret < 0)
> > + return ret;
> > +
> > + /* Shift length 4 bits = 2(15:2) + 2(0.25 LSB), see above. */
> > + s_thresh = sign_extend32(ret, 15) * (int)(MICRO >> 4);
> > +
> > + /*
> > + * Hysteresis is stored as offset, for rising temperatures, the
> > + * hysteresis range is below the alert limit where, as for falling
> > + * temperatures, the hysteresis range is above the alert limit.
> > + */
> > + hyst = min(255, abs(s_thresh - s_val) / MICRO);
> > +
> > + return i2c_smbus_write_byte_data(client,
> > + MCP9600_ALERT_HYSTERESIS(i + 1),
> > + hyst);
> > +}
> > +
> > static const struct iio_info mcp9600_info = {
> > .read_raw = mcp9600_read_raw,
> > + .read_event_config = mcp9600_read_event_config,
> > + .write_event_config = mcp9600_write_event_config,
> > + .read_event_value = mcp9600_read_thresh,
> > + .write_event_value = mcp9600_write_thresh,
> > };
> >
> > +static irqreturn_t mcp9600_alert_handler(int irq, void *private)
> > +{
> > + struct iio_dev *indio_dev = private;
> > + struct mcp9600_data *data = iio_priv(indio_dev);
> > + enum iio_event_direction dir;
> > + enum iio_modifier mod;
> > + int i, ret;
> > +
> > + for (i = 0; i < MCP9600_ALERT_COUNT; i++) {
> > + if (data->irq[i] == irq)
>
> This search for a match is a little messy. I'd be tempted
> to wrap the generic handler in a per instance interrupt handler
> (so have 4 functions) and thus move this matching to the place
> where they are registered, not the interrupt handler.
>
> There isn't a lot of shared code in here so you may be better
> off just having 4 separate interrupt handler implementations.
>
You are right, it is definitely the better solution.
> > + break;
> > + }
> > +
> > + if (i >= MCP9600_ALERT_COUNT)
> > + return IRQ_NONE;
> > +
> > + ret = i2c_smbus_read_byte_data(data->client, MCP9600_STATUS);
> > + if (ret < 0)
> > + return IRQ_HANDLED;
> > +
> > + switch (ret & MCP9600_STATUS_ALERT(i)) {
> > + case 0:
> > + return IRQ_NONE;
> > + case MCP9600_STATUS_ALERT(MCP9600_ALERT1):
> > + mod = IIO_MOD_TEMP_OBJECT;
> > + dir = IIO_EV_DIR_RISING;
> > + break;
> > + case MCP9600_STATUS_ALERT(MCP9600_ALERT2):
> > + mod = IIO_MOD_TEMP_OBJECT;
> > + dir = IIO_EV_DIR_FALLING;
> > + break;
> > + case MCP9600_STATUS_ALERT(MCP9600_ALERT3):
> > + mod = IIO_MOD_TEMP_AMBIENT;
> > + dir = IIO_EV_DIR_RISING;
> > + break;
> > + case MCP9600_STATUS_ALERT(MCP9600_ALERT4):
> > + mod = IIO_MOD_TEMP_AMBIENT;
> > + dir = IIO_EV_DIR_FALLING;
> > + break;
> > + default:
> > + return IRQ_HANDLED;
> > + }
> > +
> > + iio_push_event(indio_dev,
> > + IIO_MOD_EVENT_CODE(IIO_TEMP, 0, mod,
> > + IIO_EV_TYPE_THRESH, dir),
> > + iio_get_time_ns(indio_dev));
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static int mcp9600_probe_alerts(struct iio_dev *indio_dev)
> > +{
> > + struct mcp9600_data *data = iio_priv(indio_dev);
> > + struct i2c_client *client = data->client;
> > + struct device *dev = &client->dev;
> > + struct fwnode_handle *fwnode = dev_fwnode(dev);
> > + unsigned int irq_type;
> > + int ret, irq, i;
> > + u8 val;
> > +
> > + /*
> > + * alert1: hot junction, rising temperature
> > + * alert2: hot junction, falling temperature
> > + * alert3: cold junction, rising temperature
> > + * alert4: cold junction, falling temperature
> > + */
> > + for (i = 0; i < MCP9600_ALERT_COUNT; i++) {
> > + data->irq[i] = 0;
>
> All of data is zeroed already so this should not be needed.
>
Yes.
> > + mutex_init(&data->lock[i]);
>
> Why per interrupt locks? Seems unlikely to be a big problem
> to share one.
>
I think the code is misleading here. The locks are not per interrupt,
just for setting thresholds, since each alert has its own configuration
registers. Locks are just needed because hysteresis values depends on
threshold values. I think there should be no problem when using a single
lock for setting thresholds/hysteresis values across all alerts. Don't
know if its worth having the four locks since it it not the fastpath.
> > + irq = fwnode_irq_get_byname(fwnode, mcp9600_alert_name[i]);
> > + if (irq <= 0)
> > + continue;
> > +
> > + val = 0;
> > + irq_type = irq_get_trigger_type(irq);
> > + if (irq_type == IRQ_TYPE_EDGE_RISING)
> > + val |= MCP9600_ALERT_CFG_ACTIVE_HIGH;
> > +
> > + if (i == MCP9600_ALERT2 || i == MCP9600_ALERT4)
> > + val |= MCP9600_ALERT_CFG_FALLING;
> > +
> > + if (i == MCP9600_ALERT3 || i == MCP9600_ALERT4)
> > + val |= MCP9600_ALERT_CFG_COLD_JUNCTION;
> > +
> > + ret = i2c_smbus_write_byte_data(client,
> > + MCP9600_ALERT_CFG(i + 1),
> > + val);
> > + if (ret < 0)
> > + return ret;
> > +
> > + ret = devm_request_threaded_irq(dev, irq, NULL,
> > + mcp9600_alert_handler,
> > + IRQF_ONESHOT, "mcp9600",
> > + indio_dev);
> > + if (ret)
> > + return ret;
> > +
> > + data->irq[i] = irq;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > static int mcp9600_probe(struct i2c_client *client)
> > {
> > struct device *dev = &client->dev;
> > @@ -109,6 +456,8 @@ static int mcp9600_probe(struct i2c_client *client)
> > data = iio_priv(indio_dev);
> > data->client = client;
> >
> > + mcp9600_probe_alerts(indio_dev);
>
> Why no error check?
>
Missed that one. Thanks.
> > +
> > indio_dev->info = &mcp9600_info;
> > indio_dev->name = "mcp9600";
> > indio_dev->modes = INDIO_DIRECT_MODE;
> > @@ -140,6 +489,7 @@ static struct i2c_driver mcp9600_driver = {
> > };
> > module_i2c_driver(mcp9600_driver);
> >
> > +MODULE_AUTHOR("Dimitri Fedrau <[email protected]>");
> > MODULE_AUTHOR("Andrew Hepp <[email protected]>");
> > MODULE_DESCRIPTION("Microchip MCP9600 thermocouple EMF converter driver");
> > MODULE_LICENSE("GPL");
>
Dimitri