Add support for PEC by attaching PEC attribute to the i2c device.
Add pec_store and pec_show function for accesing the "pec" file.
Signed-off-by: Radu Sabau <[email protected]>
---
Documentation/hwmon/max31827.rst | 13 +++++--
drivers/hwmon/max31827.c | 64 ++++++++++++++++++++++++++++++++
2 files changed, 74 insertions(+), 3 deletions(-)
diff --git a/Documentation/hwmon/max31827.rst b/Documentation/hwmon/max31827.rst
index 44ab9dc064cb..9c11a9518c67 100644
--- a/Documentation/hwmon/max31827.rst
+++ b/Documentation/hwmon/max31827.rst
@@ -131,7 +131,14 @@ The Fault Queue bits select how many consecutive temperature faults must occur
before overtemperature or undertemperature faults are indicated in the
corresponding status bits.
-Notes
------
+PEC Support
+-----------
+
+When reading a register value, the PEC byte is computed and sent by the chip.
+
+PEC on word data transaction respresents a signifcant increase in bandwitdh
+usage (+33% for both write and reads) in normal conditions.
-PEC is not implemented.
+Since this operation implies there will be an extra delay to each
+transaction, PEC can be disabled or enabled through sysfs.
+Just write 1 to the "pec" file for enabling PEC and 0 for disabling it.
diff --git a/drivers/hwmon/max31827.c b/drivers/hwmon/max31827.c
index f8a13b30f100..e86f8890ee72 100644
--- a/drivers/hwmon/max31827.c
+++ b/drivers/hwmon/max31827.c
@@ -24,6 +24,7 @@
#define MAX31827_CONFIGURATION_1SHOT_MASK BIT(0)
#define MAX31827_CONFIGURATION_CNV_RATE_MASK GENMASK(3, 1)
+#define MAX31827_CONFIGURATION_PEC_EN_MASK BIT(4)
#define MAX31827_CONFIGURATION_TIMEOUT_MASK BIT(5)
#define MAX31827_CONFIGURATION_RESOLUTION_MASK GENMASK(7, 6)
#define MAX31827_CONFIGURATION_ALRM_POL_MASK BIT(8)
@@ -475,6 +476,54 @@ static ssize_t temp1_resolution_store(struct device *dev,
static DEVICE_ATTR_RW(temp1_resolution);
+static ssize_t pec_show(struct device *dev, struct device_attribute *devattr,
+ char *buf)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+
+ return scnprintf(buf, PAGE_SIZE, "%d\n", !!(client->flags & I2C_CLIENT_PEC));
+}
+
+static ssize_t pec_store(struct device *dev, struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ struct max31827_state *st = dev_get_drvdata(dev);
+ struct i2c_client *client = to_i2c_client(dev);
+ unsigned int val;
+ int err;
+
+ err = kstrtouint(buf, 10, &val);
+ if (err < 0)
+ return err;
+
+ switch (val) {
+ case 0:
+ err = regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
+ MAX31827_CONFIGURATION_PEC_EN_MASK,
+ val);
+ if (err)
+ return err;
+
+ client->flags &= ~I2C_CLIENT_PEC;
+ break;
+ case 1:
+ err = regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
+ MAX31827_CONFIGURATION_PEC_EN_MASK,
+ val);
+ if (err)
+ return err;
+
+ client->flags |= I2C_CLIENT_PEC;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return count;
+}
+
+static DEVICE_ATTR_RW(pec);
+
static struct attribute *max31827_attrs[] = {
&dev_attr_temp1_resolution.attr,
NULL
@@ -578,6 +627,11 @@ static int max31827_init_client(struct max31827_state *st,
return regmap_write(st->regmap, MAX31827_CONFIGURATION_REG, res);
}
+static void max31827_remove_pec(void *dev)
+{
+ device_remove_file(dev, &dev_attr_pec);
+}
+
static const struct hwmon_channel_info *max31827_info[] = {
HWMON_CHANNEL_INFO(temp, HWMON_T_ENABLE | HWMON_T_INPUT | HWMON_T_MIN |
HWMON_T_MIN_HYST | HWMON_T_MIN_ALARM |
@@ -627,6 +681,16 @@ static int max31827_probe(struct i2c_client *client)
if (err)
return err;
+ if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_PEC)) {
+ err = device_create_file(dev, &dev_attr_pec);
+ if (err)
+ return err;
+
+ err = devm_add_action_or_reset(dev, max31827_remove_pec, dev);
+ if (err)
+ return err;
+ }
+
hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, st,
&max31827_chip_info,
max31827_groups);
--
2.34.1
On Thu, May 23, 2024 at 03:10:56PM +0300, Radu Sabau wrote:
> Add support for PEC by attaching PEC attribute to the i2c device.
> Add pec_store and pec_show function for accesing the "pec" file.
>
> Signed-off-by: Radu Sabau <[email protected]>
> ---
Change log missing.
> Documentation/hwmon/max31827.rst | 13 +++++--
> drivers/hwmon/max31827.c | 64 ++++++++++++++++++++++++++++++++
> 2 files changed, 74 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/hwmon/max31827.rst b/Documentation/hwmon/max31827.rst
> index 44ab9dc064cb..9c11a9518c67 100644
> --- a/Documentation/hwmon/max31827.rst
> +++ b/Documentation/hwmon/max31827.rst
> @@ -131,7 +131,14 @@ The Fault Queue bits select how many consecutive temperature faults must occur
> before overtemperature or undertemperature faults are indicated in the
> corresponding status bits.
>
> -Notes
> ------
> +PEC Support
> +-----------
> +
> +When reading a register value, the PEC byte is computed and sent by the chip.
> +
> +PEC on word data transaction respresents a signifcant increase in bandwitdh
> +usage (+33% for both write and reads) in normal conditions.
>
> -PEC is not implemented.
> +Since this operation implies there will be an extra delay to each
> +transaction, PEC can be disabled or enabled through sysfs.
> +Just write 1 to the "pec" file for enabling PEC and 0 for disabling it.
> diff --git a/drivers/hwmon/max31827.c b/drivers/hwmon/max31827.c
> index f8a13b30f100..e86f8890ee72 100644
> --- a/drivers/hwmon/max31827.c
> +++ b/drivers/hwmon/max31827.c
> @@ -24,6 +24,7 @@
>
> #define MAX31827_CONFIGURATION_1SHOT_MASK BIT(0)
> #define MAX31827_CONFIGURATION_CNV_RATE_MASK GENMASK(3, 1)
> +#define MAX31827_CONFIGURATION_PEC_EN_MASK BIT(4)
> #define MAX31827_CONFIGURATION_TIMEOUT_MASK BIT(5)
> #define MAX31827_CONFIGURATION_RESOLUTION_MASK GENMASK(7, 6)
> #define MAX31827_CONFIGURATION_ALRM_POL_MASK BIT(8)
> @@ -475,6 +476,54 @@ static ssize_t temp1_resolution_store(struct device *dev,
>
> static DEVICE_ATTR_RW(temp1_resolution);
>
> +static ssize_t pec_show(struct device *dev, struct device_attribute *devattr,
> + char *buf)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> +
> + return scnprintf(buf, PAGE_SIZE, "%d\n", !!(client->flags & I2C_CLIENT_PEC));
> +}
> +
> +static ssize_t pec_store(struct device *dev, struct device_attribute *devattr,
> + const char *buf, size_t count)
> +{
> + struct max31827_state *st = dev_get_drvdata(dev);
> + struct i2c_client *client = to_i2c_client(dev);
> + unsigned int val;
> + int err;
> +
> + err = kstrtouint(buf, 10, &val);
> + if (err < 0)
> + return err;
> +
> + switch (val) {
> + case 0:
> + err = regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
> + MAX31827_CONFIGURATION_PEC_EN_MASK,
> + val);
While correct, this is misleading. Should write 0.
> + if (err)
> + return err;
> +
> + client->flags &= ~I2C_CLIENT_PEC;
> + break;
> + case 1:
> + err = regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
> + MAX31827_CONFIGURATION_PEC_EN_MASK,
> + val);
This is wrong. s/val/MAX31827_CONFIGURATION_PEC_EN_MASK/
Guenter
On Thu, 2024-05-23 at 07:19 -0700, Guenter Roeck wrote:
> On Thu, May 23, 2024 at 03:10:56PM +0300, Radu Sabau wrote:
> > Add support for PEC by attaching PEC attribute to the i2c device.
> > Add pec_store and pec_show function for accesing the "pec" file.
> >
> > Signed-off-by: Radu Sabau <[email protected]>
> > ---
>
> Change log missing.
>
> > Documentation/hwmon/max31827.rst | 13 +++++--
> > drivers/hwmon/max31827.c | 64 ++++++++++++++++++++++++++++++++
> > 2 files changed, 74 insertions(+), 3 deletions(-)
> >
> > diff --git a/Documentation/hwmon/max31827.rst b/Documentation/hwmon/max31827.rst
> > index 44ab9dc064cb..9c11a9518c67 100644
> > --- a/Documentation/hwmon/max31827.rst
> > +++ b/Documentation/hwmon/max31827.rst
> > @@ -131,7 +131,14 @@ The Fault Queue bits select how many consecutive temperature
> > faults must occur
> > before overtemperature or undertemperature faults are indicated in the
> > corresponding status bits.
> >
> > -Notes
> > ------
> > +PEC Support
> > +-----------
> > +
> > +When reading a register value, the PEC byte is computed and sent by the chip.
> > +
> > +PEC on word data transaction respresents a signifcant increase in bandwitdh
> > +usage (+33% for both write and reads) in normal conditions.
> >
> > -PEC is not implemented.
> > +Since this operation implies there will be an extra delay to each
> > +transaction, PEC can be disabled or enabled through sysfs.
> > +Just write 1 to the "pec" file for enabling PEC and 0 for disabling it.
> > diff --git a/drivers/hwmon/max31827.c b/drivers/hwmon/max31827.c
> > index f8a13b30f100..e86f8890ee72 100644
> > --- a/drivers/hwmon/max31827.c
> > +++ b/drivers/hwmon/max31827.c
> > @@ -24,6 +24,7 @@
> >
> > #define MAX31827_CONFIGURATION_1SHOT_MASK BIT(0)
> > #define MAX31827_CONFIGURATION_CNV_RATE_MASK GENMASK(3, 1)
> > +#define MAX31827_CONFIGURATION_PEC_EN_MASK BIT(4)
> > #define MAX31827_CONFIGURATION_TIMEOUT_MASK BIT(5)
> > #define MAX31827_CONFIGURATION_RESOLUTION_MASK GENMASK(7, 6)
> > #define MAX31827_CONFIGURATION_ALRM_POL_MASK BIT(8)
> > @@ -475,6 +476,54 @@ static ssize_t temp1_resolution_store(struct device *dev,
> >
> > static DEVICE_ATTR_RW(temp1_resolution);
> >
> > +static ssize_t pec_show(struct device *dev, struct device_attribute *devattr,
> > + char *buf)
> > +{
> > + struct i2c_client *client = to_i2c_client(dev);
> > +
> > + return scnprintf(buf, PAGE_SIZE, "%d\n", !!(client->flags &
> > I2C_CLIENT_PEC));
> > +}
> > +
> > +static ssize_t pec_store(struct device *dev, struct device_attribute *devattr,
> > + const char *buf, size_t count)
> > +{
> > + struct max31827_state *st = dev_get_drvdata(dev);
> > + struct i2c_client *client = to_i2c_client(dev);
> > + unsigned int val;
> > + int err;
> > +
> > + err = kstrtouint(buf, 10, &val);
> > + if (err < 0)
> > + return err;
> > +
> > + switch (val) {
> > + case 0:
> > + err = regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
> > + MAX31827_CONFIGURATION_PEC_EN_MASK,
> > + val);
>
> While correct, this is misleading. Should write 0.
>
> > + if (err)
> > + return err;
> > +
> > + client->flags &= ~I2C_CLIENT_PEC;
> > + break;
> > + case 1:
> > + err = regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
> > + MAX31827_CONFIGURATION_PEC_EN_MASK,
> > + val);
>
> This is wrong. s/val/MAX31827_CONFIGURATION_PEC_EN_MASK/
>
>
Then, maybe use regmap_set_bits()...
- Nuno Sá
On 5/24/24 00:00, Nuno Sá wrote:
> On Thu, 2024-05-23 at 07:19 -0700, Guenter Roeck wrote:
>> On Thu, May 23, 2024 at 03:10:56PM +0300, Radu Sabau wrote:
>>> Add support for PEC by attaching PEC attribute to the i2c device.
>>> Add pec_store and pec_show function for accesing the "pec" file.
>>>
>>> Signed-off-by: Radu Sabau <[email protected]>
>>> ---
>>
>> Change log missing.
>>
>>> Documentation/hwmon/max31827.rst | 13 +++++--
>>> drivers/hwmon/max31827.c | 64 ++++++++++++++++++++++++++++++++
>>> 2 files changed, 74 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/Documentation/hwmon/max31827.rst b/Documentation/hwmon/max31827.rst
>>> index 44ab9dc064cb..9c11a9518c67 100644
>>> --- a/Documentation/hwmon/max31827.rst
>>> +++ b/Documentation/hwmon/max31827.rst
>>> @@ -131,7 +131,14 @@ The Fault Queue bits select how many consecutive temperature
>>> faults must occur
>>> before overtemperature or undertemperature faults are indicated in the
>>> corresponding status bits.
>>>
>>> -Notes
>>> ------
>>> +PEC Support
>>> +-----------
>>> +
>>> +When reading a register value, the PEC byte is computed and sent by the chip.
>>> +
>>> +PEC on word data transaction respresents a signifcant increase in bandwitdh
>>> +usage (+33% for both write and reads) in normal conditions.
>>>
>>> -PEC is not implemented.
>>> +Since this operation implies there will be an extra delay to each
>>> +transaction, PEC can be disabled or enabled through sysfs.
>>> +Just write 1 to the "pec" file for enabling PEC and 0 for disabling it.
>>> diff --git a/drivers/hwmon/max31827.c b/drivers/hwmon/max31827.c
>>> index f8a13b30f100..e86f8890ee72 100644
>>> --- a/drivers/hwmon/max31827.c
>>> +++ b/drivers/hwmon/max31827.c
>>> @@ -24,6 +24,7 @@
>>>
>>> #define MAX31827_CONFIGURATION_1SHOT_MASK BIT(0)
>>> #define MAX31827_CONFIGURATION_CNV_RATE_MASK GENMASK(3, 1)
>>> +#define MAX31827_CONFIGURATION_PEC_EN_MASK BIT(4)
>>> #define MAX31827_CONFIGURATION_TIMEOUT_MASK BIT(5)
>>> #define MAX31827_CONFIGURATION_RESOLUTION_MASK GENMASK(7, 6)
>>> #define MAX31827_CONFIGURATION_ALRM_POL_MASK BIT(8)
>>> @@ -475,6 +476,54 @@ static ssize_t temp1_resolution_store(struct device *dev,
>>>
>>> static DEVICE_ATTR_RW(temp1_resolution);
>>>
>>> +static ssize_t pec_show(struct device *dev, struct device_attribute *devattr,
>>> + char *buf)
>>> +{
>>> + struct i2c_client *client = to_i2c_client(dev);
>>> +
>>> + return scnprintf(buf, PAGE_SIZE, "%d\n", !!(client->flags &
>>> I2C_CLIENT_PEC));
>>> +}
>>> +
>>> +static ssize_t pec_store(struct device *dev, struct device_attribute *devattr,
>>> + const char *buf, size_t count)
>>> +{
>>> + struct max31827_state *st = dev_get_drvdata(dev);
>>> + struct i2c_client *client = to_i2c_client(dev);
>>> + unsigned int val;
>>> + int err;
>>> +
>>> + err = kstrtouint(buf, 10, &val);
>>> + if (err < 0)
>>> + return err;
>>> +
>>> + switch (val) {
>>> + case 0:
>>> + err = regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
>>> + MAX31827_CONFIGURATION_PEC_EN_MASK,
>>> + val);
>>
>> While correct, this is misleading. Should write 0.
>>
>>> + if (err)
>>> + return err;
>>> +
>>> + client->flags &= ~I2C_CLIENT_PEC;
>>> + break;
>>> + case 1:
>>> + err = regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
>>> + MAX31827_CONFIGURATION_PEC_EN_MASK,
>>> + val);
>>
>> This is wrong. s/val/MAX31827_CONFIGURATION_PEC_EN_MASK/
>>
>>
>
> Then, maybe use regmap_set_bits()...
Good point, and regmap_clear_bits() above.
Guenter
>
> - Nuno Sá
>