Hi Guenter,
Sorry for the late review, originally I planned to do a quick review
but apparently I am simply unable to do that. So here comes a complete
review. As usual, pick what you agree with and feel free to ignore the
rest :)
On Sun, 16 Dec 2012 21:33:09 -0800, Guenter Roeck wrote:
> Add support for MAX6581, MAX6602, MAX6622, MAX6636, MAX6689, MAX6693,
> MAX6694, MAX6697, MAX6698, and MAX6699 temperature sensors
>
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
> v2:
> - Add suppport for platform data and devicetree based chip initialization
> - Drop S_IRUGOWU macro: s/S_IRUGOWU/S_IRUGO | S_IWUSR/
>
> Documentation/devicetree/bindings/i2c/max6697.txt | 45 ++
> Documentation/hwmon/max6697 | 57 ++
> drivers/hwmon/Kconfig | 11 +
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/max6697.c | 634 +++++++++++++++++++++
> include/linux/platform_data/max6697.h | 25 +
> 6 files changed, 773 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/i2c/max6697.txt
> create mode 100644 Documentation/hwmon/max6697
> create mode 100644 drivers/hwmon/max6697.c
> create mode 100644 include/linux/platform_data/max6697.h
>
> diff --git a/Documentation/devicetree/bindings/i2c/max6697.txt b/Documentation/devicetree/bindings/i2c/max6697.txt
> new file mode 100644
> index 0000000..3e867e2
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/max6697.txt
> @@ -0,0 +1,45 @@
> +max6697 properties
> +
> +Required properties:
> +- compatible:
> + Should be one of
> + maxim,max6581
> + maxim,max6602
> + maxim,max6622
> + maxim,max6636
> + maxim,max6689
> + maxim,max6693
> + maxim,max6694
> + maxim,max6697
> + maxim,max6698
> + maxim,max6699
> +- reg: I2C address
> +
> +Optional properties:
Your definition of "optional" is questionable. Setting _any_ of these
properties will cause _all_ others to be considered as 0 and the chip
will be reprogrammed with these settings. I'd say this is unexpected and
confusing. I'd expect struct max6697_platform_data to be able to store
"don't change" for every setting, so that only the properties actually
provided are written to the chip.
If you really don't want to do that, then you should make it prominently
visible both here and in max6697.h that one should either set all
properties or none. Beware though that this may still cause trouble if
you ever have to add one property to the set in the future.
> +- smbus-timeout-disable
> + Set to enable SMBus timeout
> +- extended-range-enable
> + Only valid for MAX6581. Set to enable extended temperature range.
> +- alert-mask
> + Alert bit mask. Alert disabled for bits set.
> +- over-temperature-mask
> + Over temperature bit mask. Over temperature reporting disabled for
> + bits set.
> +- resistance-cancellation
> + Boolean for all chips other than MAX6581. Enabled if set.
> + For MAX6581, resistance cancellation enabled for all channels if
> + specified as boolean, otherwise as per bit mask specified.
> +- transistor-ideality
> + For MAX6581 only. Two values; first is bit mask, second is ideality
> + select value as per MAX6581 data sheet.
I'm not familiar with OF properties... Is there any standard for the
properties above? If not, and other drivers implement similar
properties, did you make sure to follow existing common practice?
> +
> +Example:
> +
> +temp-sensor@1a {
> + compatible = "maxim,max6697";
> + reg = <0x1a>;
> + smbus-timeout-disable;
> + resistance-cancellation;
> + alert-mask = <0xff>;
> + over-temperature-mask = <0xff>;
> +};
For a 7-channel chip, mask values of 0xff make little sense IMHO.
> diff --git a/Documentation/hwmon/max6697 b/Documentation/hwmon/max6697
> new file mode 100644
> index 0000000..35fc2e9
> --- /dev/null
> +++ b/Documentation/hwmon/max6697
> @@ -0,0 +1,57 @@
> +Kernel driver max6697
> +=====================
> +
> +Supported chips:
> + * Maxim MAX6581
> + Prefix: 'max6581'
> + Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6581.pdf
> + * Maxim MAX6602
> + Prefix: 'max6602'
> + Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6602.pdf
> + * Maxim MAX6622
> + Prefix: 'max6622'
> + Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6622.pdf
> + * Maxim MAX6636
> + Prefix: 'max6636'
> + Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6636.pdf
> + * Maxim MAX6689
> + Prefix: 'max6689'
> + Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6689.pdf
> + * Maxim MAX6693
> + Prefix: 'max6693'
> + Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6693.pdf
> + * Maxim MAX6694
> + Prefix: 'max6694'
> + Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6694.pdf
> + * Maxim MAX6697
> + Prefix: 'max6697'
> + Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6697.pdf
> + * Maxim MAX6698
> + Prefix: 'max6698'
> + Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6698.pdf
> + * Maxim MAX6699
> + Prefix: 'max6699'
> + Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6699.pdf
> +
> +Author:
> + Guenter Roeck <linux@xxxxxxxxxxxx>
> +
> +Description
> +-----------
> +
> +This driver implements support for several MAX6697 compatible temperature sensor
> +chips. The chips support one local temperature sensor plus four or six remote
Or seven for the MAX6581.
> +temperature sensors. Remote temperature sensors are diode-connected thermal
> +transitors, except for MAX6698 which supports three diode-connected thermal
> +transistors plus three thermistors in addition to the local temperature sensor.
> +
> +The driver provides the following sysfs attributes. temp1 is the local (chip)
> +temperature, temp[2..n] are remote temperatures. The actually supported
> +per-channel attributes are chip type and channel dependent.
> +
> +tempX_input ro remote temperature
> +tempX_max rw remote temperature maximum threshold for alarm
"for alarm" seems redundant.
> +tempX_max_alarm ro remote temperature maximum threshold alarm
> +tempX_crit rw remote temperature critical threshold for alarm
Ditto.
> +tempX_crit_alarm ro remote temperature critical threshold alarm
The use of "remote" in the descriptions above is confusing, as X=1
corresponds to a local temperature.
> +tempX_fault ro remote temperature diode fault
I would also suggest using uppercase RO and RW to increase readability,
matching Documentation/hwmon/sysfs-interface.
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index c4633de..14f7ac9 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -844,6 +844,17 @@ config SENSORS_MAX6650
> This driver can also be built as a module. If so, the module
> will be called max6650.
>
> +config SENSORS_MAX6697
> + tristate "Maxim MAX6697 and compatibles"
> + depends on I2C
> + help
> + If you say yes here you get support for MAX6581, MAX6602, MAX6622,
> + MAX6636, MAX6689, MAX6693, MAX6694, MAX6697, MAX6698, and MAX6699
> + temperature sensor chips.
> +
> + This driver can also be built as a module. If so, the module
> + will be called max6697.
> +
> config SENSORS_MCP3021
> tristate "Microchip MCP3021 and compatibles"
> depends on I2C
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 8d5fcb5..d23646d 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -98,6 +98,7 @@ obj-$(CONFIG_SENSORS_MAX197) += max197.o
> obj-$(CONFIG_SENSORS_MAX6639) += max6639.o
> obj-$(CONFIG_SENSORS_MAX6642) += max6642.o
> obj-$(CONFIG_SENSORS_MAX6650) += max6650.o
> +obj-$(CONFIG_SENSORS_MAX6697) += max6697.o
> obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
> obj-$(CONFIG_SENSORS_MCP3021) += mcp3021.o
> obj-$(CONFIG_SENSORS_NTC_THERMISTOR) += ntc_thermistor.o
> diff --git a/drivers/hwmon/max6697.c b/drivers/hwmon/max6697.c
> new file mode 100644
> index 0000000..597cb98
> --- /dev/null
> +++ b/drivers/hwmon/max6697.c
> @@ -0,0 +1,634 @@
> +/*
> + * Copyright (c) 2012 Guenter Roeck <linux@xxxxxxxxxxxx>
> + *
> + * based on max1668.c
> + * Copyright (c) 2011 David George <david.george@xxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/slab.h>
> +#include <linux/jiffies.h>
> +#include <linux/i2c.h>
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/err.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +
> +#include <linux/platform_data/max6697.h>
> +
> +enum chips { max6581, max6602, max6622, max6636, max6689, max6693, max6694,
> + max6697, max6698, max6699 };
> +
> +/* Report local sensor as temp1 */
> +
> +static const u8 MAX6697_REG_TEMP[] = { 7, 1, 2, 3, 4, 5, 6, 8 };
Hexadecimal values would be more consistent.
> +static const u8 MAX6697_REG_TEMP_EXT[] = {
> + 0x57, 0x09, 0x52, 0x53, 0x54, 0x55, 0x56, 0 };
> +static const u8 MAX6697_REG_MAX[] = {
> + 0x17, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x18 };
> +static const u8 MAX6697_REG_CRIT[] = {
> + 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27 };
> +
> +#define MAX6697_REG_STAT(n) (0x44 + (n))
> +
> +#define MAX6697_REG_CONFIG 0x41
> +#define MAX6581_CONF_EXTENDED (1 << 1)
> +#define MAX6697_CONF_RESISTANCE (1 << 3)
> +#define MAX6697_CONF_TIMEOUT (1 << 5)
> +#define MAX6697_REG_ALERT_MASK 0x42
> +#define MAX6697_REG_OVERT_MASK 0x43
> +
> +#define MAX6581_REG_RESISTANCE 0x4a
> +#define MAX6581_REG_IDEALITY 0x4b
> +#define MAX6581_REG_IDEALITY_SELECT 0x4c
> +#define MAX6581_REG_OFFSET 0x4d
> +#define MAX6581_REG_OFFSET_SELECT 0x4e
> +
> +struct max6697_chip_data {
> + int channels;
> + u32 have_ext;
> + u32 have_crit;
> + u32 have_fault;
> + const u8 *alarm_map;
> +};
> +
> +struct max6697_data {
> + struct device *hwmon_dev;
> +
> + enum chips type;
> + const struct max6697_chip_data *chip;
> +
> + struct mutex update_lock;
> + unsigned long last_updated; /* In jiffies */
> + bool valid; /* true if following fields are valid */
> +
> + /* 1x local and up to 7x remote */
> + u8 temp[8][4]; /* [nr][0]=temp [1]=ext [2]=max [3]=crit */
Maybe it would make sense to define constants for these? Otherwise it's
easy to get them wrong.
> + u32 alarms;
> +};
> +
> +/* Diode fault status bits on MAX6581 are right shifted by one bit */
> +static const u8 max6581_alarm_map[] = {
> + 0, 0, 1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15,
> + 16, 17, 18, 19, 20, 21, 22, 23 };
> +
> +static const struct max6697_chip_data max6697_chip_data[] = {
> + [max6581] = {
> + .channels = 8,
> + .have_crit = 0xff,
> + .have_ext = 0xfe,
The datasheet I have here suggest that the local temperature has the
extended bits while the 7th external channel does not. This would lead
to .have_ext = 0x7f.
> + .have_fault = 0xfe,
> + .alarm_map = max6581_alarm_map,
> + },
> + [max6602] = {
> + .channels = 5,
> + .have_crit = 0x12,
> + .have_ext = 0x02,
> + .have_fault = 0x1e,
> + },
> + [max6636] = {
> + .channels = 7,
> + .have_crit = 0x72,
> + .have_ext = 0x02,
> + .have_fault = 0x7e,
> + },
> + [max6622] = {
> + .channels = 5,
> + .have_crit = 0x12,
> + .have_ext = 0x02,
> + .have_fault = 0x1e,
> + },
Any reason for not sorting these two in numeric order?
> + [max6689] = {
> + .channels = 7,
> + .have_crit = 0x72,
> + .have_ext = 0x02,
> + .have_fault = 0x7e,
> + },
> + [max6693] = {
> + .channels = 7,
> + .have_crit = 0x72,
> + .have_ext = 0x02,
> + .have_fault = 0x7e,
> + },
> + [max6694] = {
> + .channels = 5,
> + .have_crit = 0x12,
> + .have_ext = 0x02,
> + .have_fault = 0x1e,
> + },
> + [max6697] = {
> + .channels = 7,
> + .have_crit = 0x72,
> + .have_ext = 0x02,
> + .have_fault = 0x7e,
> + },
> + [max6698] = {
> + .channels = 7,
> + .have_crit = 0x72,
> + .have_ext = 0x02,
> + .have_fault = 0x0e,
> + },
> + [max6699] = {
> + .channels = 5,
> + .have_crit = 0x12,
> + .have_ext = 0x02,
> + .have_fault = 0x1e,
> + },
> +};
> +
> +static struct max6697_data *max6697_update_device(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct max6697_data *data = i2c_get_clientdata(client);
> + struct max6697_data *ret = data;
> + int val;
> + int i;
> +
> + mutex_lock(&data->update_lock);
> +
> + if (data->valid &&
> + !time_after(jiffies, data->last_updated + HZ + HZ / 2))
> + goto abort;
This cache lifetime seems a bit large at least for the 5-channel chips,
but also insufficient for the MAX6581. For example the MAX6602 can
complete a full conversion cycle in 468 ms worst case if I read the
datasheet properly. But the MAX6581 may need up to 2496 ms. Maybe the
cache lifetime should depend on the chip variant and maybe even its
configuration?
> +
> + for (i = 0; i < data->chip->channels; i++) {
> + if (data->chip->have_ext & (1 << i)) {
> + val = i2c_smbus_read_byte_data(client,
> + MAX6697_REG_TEMP_EXT[i]);
> + if (unlikely(val < 0)) {
> + ret = ERR_PTR(val);
> + goto abort;
> + }
> + data->temp[i][1] = val;
> + }
> +
> + val = i2c_smbus_read_byte_data(client, MAX6697_REG_TEMP[i]);
> + if (unlikely(val < 0)) {
> + ret = ERR_PTR(val);
> + goto abort;
> + }
> + data->temp[i][0] = val;
> +
> + val = i2c_smbus_read_byte_data(client, MAX6697_REG_MAX[i]);
> + if (unlikely(val < 0)) {
> + ret = ERR_PTR(val);
> + goto abort;
> + }
> + data->temp[i][2] = val;
> +
> + if (data->chip->have_crit & (1 << i)) {
> + val = i2c_smbus_read_byte_data(client,
> + MAX6697_REG_CRIT[i]);
> + if (unlikely(val < 0)) {
> + ret = ERR_PTR(val);
> + goto abort;
> + }
> + data->temp[i][3] = val;
> + }
> + }
> +
> + data->alarms = 0;
> + for (i = 0; i < 3; i++) {
> + val = i2c_smbus_read_byte_data(client, MAX6697_REG_STAT(i));
> + if (unlikely(val < 0)) {
> + ret = ERR_PTR(val);
> + goto abort;
> + }
> + data->alarms = (data->alarms << 8) | val;
> + }
data->alarms is accessed in function show_alarm() without the
data->update_lock mutex being held. This makes this incremental
construction of data->alarms racy. You should either hold the mutex when
accessing data->alarms in function show_alarm(), or use a temporary
variable here and copy the final result to data->alarms when done.
> +
> + data->last_updated = jiffies;
> + data->valid = true;
> +abort:
> + mutex_unlock(&data->update_lock);
> +
> + return ret;
> +}
> +
> +static ssize_t show_temp11(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + int nr = to_sensor_dev_attr_2(devattr)->nr;
> + int index = to_sensor_dev_attr_2(devattr)->index;
> + struct max6697_data *data = max6697_update_device(dev);
> +
> + if (IS_ERR(data))
> + return PTR_ERR(data);
> +
> + return sprintf(buf, "%d\n",
> + ((data->temp[nr][index] << 3) |
> + (data->temp[nr][index + 1] >> 5)) * 125);
I can't see this code dealing properly with the negative temperature
values supported by the MAX6581, nor with its extended format... nor
with its normal format BTW, as it turns out to be completely different
from the other chips.
Did you have a formal request to support the MAX6581? It is different
enough from the other support chips that I wouldn't mind dropping
support for it from this driver, and only add support for it if someone
needs it.
As a side note, index will always be 0, so you might as well hard-code
it for optimization (and then rename the function to show_temp_input
for clarity.)
> +}
> +
> +static ssize_t show_temp(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + int nr = to_sensor_dev_attr_2(devattr)->nr;
> + int index = to_sensor_dev_attr_2(devattr)->index;
> + struct max6697_data *data = max6697_update_device(dev);
> +
> + if (IS_ERR(data))
> + return PTR_ERR(data);
> +
> + return sprintf(buf, "%d\n", data->temp[nr][index] * 1000);
Ditto.
> +}
> +
> +static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + int index = to_sensor_dev_attr(attr)->index;
> + struct max6697_data *data = max6697_update_device(dev);
> +
> + if (IS_ERR(data))
> + return PTR_ERR(data);
> +
> + if (data->chip->alarm_map)
> + index = data->chip->alarm_map[index];
> +
> + return sprintf(buf, "%u\n", (data->alarms >> index) & 0x1);
> +}
> +
> +static ssize_t set_temp(struct device *dev,
> + struct device_attribute *devattr,
> + const char *buf, size_t count)
> +{
> + int nr = to_sensor_dev_attr_2(devattr)->nr;
> + int index = to_sensor_dev_attr_2(devattr)->index;
> + struct i2c_client *client = to_i2c_client(dev);
> + struct max6697_data *data = i2c_get_clientdata(client);
> + long temp;
> + int ret;
> +
> + ret = kstrtol(buf, 10, &temp);
> + if (ret < 0)
> + return ret;
> +
> + mutex_lock(&data->update_lock);
> + data->temp[nr][index] = SENSORS_LIMIT(temp / 1000, 0, 127);
Proper rounding would be appreciated here.
> + ret = i2c_smbus_write_byte_data(client,
> + index == 2 ? MAX6697_REG_MAX[nr]
> + : MAX6697_REG_CRIT[nr],
> + data->temp[nr][index]);
> + if (ret < 0)
> + count = ret;
count is unsigned!
> + mutex_unlock(&data->update_lock);
> +
> + return count;
> +}
> +
> +static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp11, NULL, 0, 0);
> +static SENSOR_DEVICE_ATTR_2(temp1_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 0, 2);
> +static SENSOR_DEVICE_ATTR_2(temp1_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 0, 3);
> +
> +static SENSOR_DEVICE_ATTR_2(temp2_input, S_IRUGO, show_temp11, NULL, 1, 0);
> +static SENSOR_DEVICE_ATTR_2(temp2_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 1, 2);
> +static SENSOR_DEVICE_ATTR_2(temp2_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 1, 3);
> +
> +static SENSOR_DEVICE_ATTR_2(temp3_input, S_IRUGO, show_temp11, NULL, 2, 0);
> +static SENSOR_DEVICE_ATTR_2(temp3_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 2, 2);
> +static SENSOR_DEVICE_ATTR_2(temp3_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 2, 3);
> +
> +static SENSOR_DEVICE_ATTR_2(temp4_input, S_IRUGO, show_temp11, NULL, 3, 0);
> +static SENSOR_DEVICE_ATTR_2(temp4_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 3, 2);
> +static SENSOR_DEVICE_ATTR_2(temp4_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 3, 3);
> +
> +static SENSOR_DEVICE_ATTR_2(temp5_input, S_IRUGO, show_temp11, NULL, 4, 0);
> +static SENSOR_DEVICE_ATTR_2(temp5_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 4, 2);
> +static SENSOR_DEVICE_ATTR_2(temp5_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 4, 3);
> +
> +static SENSOR_DEVICE_ATTR_2(temp6_input, S_IRUGO, show_temp11, NULL, 5, 0);
> +static SENSOR_DEVICE_ATTR_2(temp6_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 5, 2);
> +static SENSOR_DEVICE_ATTR_2(temp6_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 5, 3);
> +
> +static SENSOR_DEVICE_ATTR_2(temp7_input, S_IRUGO, show_temp11, NULL, 6, 0);
> +static SENSOR_DEVICE_ATTR_2(temp7_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 6, 2);
> +static SENSOR_DEVICE_ATTR_2(temp7_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 6, 3);
> +
> +static SENSOR_DEVICE_ATTR_2(temp8_input, S_IRUGO, show_temp11, NULL, 7, 0);
> +static SENSOR_DEVICE_ATTR_2(temp8_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 7, 2);
> +static SENSOR_DEVICE_ATTR_2(temp8_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
> + 7, 3);
> +
> +static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 22);
> +static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 16);
> +static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 17);
> +static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_alarm, NULL, 18);
> +static SENSOR_DEVICE_ATTR(temp5_max_alarm, S_IRUGO, show_alarm, NULL, 19);
> +static SENSOR_DEVICE_ATTR(temp6_max_alarm, S_IRUGO, show_alarm, NULL, 20);
> +static SENSOR_DEVICE_ATTR(temp7_max_alarm, S_IRUGO, show_alarm, NULL, 21);
> +static SENSOR_DEVICE_ATTR(temp8_max_alarm, S_IRUGO, show_alarm, NULL, 23);
> +
> +static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 14);
> +static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 8);
> +static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
> +static SENSOR_DEVICE_ATTR(temp4_crit_alarm, S_IRUGO, show_alarm, NULL, 10);
> +static SENSOR_DEVICE_ATTR(temp5_crit_alarm, S_IRUGO, show_alarm, NULL, 11);
> +static SENSOR_DEVICE_ATTR(temp6_crit_alarm, S_IRUGO, show_alarm, NULL, 12);
> +static SENSOR_DEVICE_ATTR(temp7_crit_alarm, S_IRUGO, show_alarm, NULL, 13);
> +static SENSOR_DEVICE_ATTR(temp8_crit_alarm, S_IRUGO, show_alarm, NULL, 15);
> +
> +static SENSOR_DEVICE_ATTR(temp1_fault, S_IRUGO, show_alarm, NULL, 0);
This one will never be used, as temp1 is local and can't be faulty.
> +static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 1);
> +static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 2);
> +static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_alarm, NULL, 3);
> +static SENSOR_DEVICE_ATTR(temp5_fault, S_IRUGO, show_alarm, NULL, 4);
> +static SENSOR_DEVICE_ATTR(temp6_fault, S_IRUGO, show_alarm, NULL, 5);
> +static SENSOR_DEVICE_ATTR(temp7_fault, S_IRUGO, show_alarm, NULL, 6);
> +static SENSOR_DEVICE_ATTR(temp8_fault, S_IRUGO, show_alarm, NULL, 7);
> +
> +static struct attribute *max6697_attributes[] = {
> + &sensor_dev_attr_temp1_input.dev_attr.attr,
> + &sensor_dev_attr_temp1_max.dev_attr.attr,
> + &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp1_crit.dev_attr.attr,
> + &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp1_fault.dev_attr.attr,
> +
> + &sensor_dev_attr_temp2_input.dev_attr.attr,
> + &sensor_dev_attr_temp2_max.dev_attr.attr,
> + &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp2_crit.dev_attr.attr,
> + &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp2_fault.dev_attr.attr,
> +
> + &sensor_dev_attr_temp3_input.dev_attr.attr,
> + &sensor_dev_attr_temp3_max.dev_attr.attr,
> + &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp3_crit.dev_attr.attr,
> + &sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp3_fault.dev_attr.attr,
> +
> + &sensor_dev_attr_temp4_input.dev_attr.attr,
> + &sensor_dev_attr_temp4_max.dev_attr.attr,
> + &sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp4_crit.dev_attr.attr,
> + &sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp4_fault.dev_attr.attr,
> +
> + &sensor_dev_attr_temp5_input.dev_attr.attr,
> + &sensor_dev_attr_temp5_max.dev_attr.attr,
> + &sensor_dev_attr_temp5_max_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp5_crit.dev_attr.attr,
> + &sensor_dev_attr_temp5_crit_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp5_fault.dev_attr.attr,
> +
> + &sensor_dev_attr_temp6_input.dev_attr.attr,
> + &sensor_dev_attr_temp6_max.dev_attr.attr,
> + &sensor_dev_attr_temp6_max_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp6_crit.dev_attr.attr,
> + &sensor_dev_attr_temp6_crit_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp6_fault.dev_attr.attr,
> +
> + &sensor_dev_attr_temp7_input.dev_attr.attr,
> + &sensor_dev_attr_temp7_max.dev_attr.attr,
> + &sensor_dev_attr_temp7_max_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp7_crit.dev_attr.attr,
> + &sensor_dev_attr_temp7_crit_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp7_fault.dev_attr.attr,
> +
> + &sensor_dev_attr_temp8_input.dev_attr.attr,
> + &sensor_dev_attr_temp8_max.dev_attr.attr,
> + &sensor_dev_attr_temp8_max_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp8_crit.dev_attr.attr,
> + &sensor_dev_attr_temp8_crit_alarm.dev_attr.attr,
> + &sensor_dev_attr_temp8_fault.dev_attr.attr,
> +
> + NULL
> +};
> +
> +static const struct attribute_group max6697_group = {
> + .attrs = max6697_attributes,
> +};
> +
> +static void max6697_get_config_of(struct device_node *node,
> + struct max6697_platform_data *pdata)
> +{
> + int len;
> + const __be32 *prop;
> +
> + prop = of_get_property(node, "smbus-timeout-disable", &len);
> + if (prop)
> + pdata->smbus_timeout_disable = true;
> + prop = of_get_property(node, "extended_range_enable", &len);
Underscores or dashes?
> + if (prop)
> + pdata->extended_range_enable = true;
> + prop = of_get_property(node, "alert-mask", &len);
> + if (prop && len == sizeof(u32))
> + pdata->alert_mask = be32_to_cpu(prop[0]);
> + prop = of_get_property(node, "over-temperature-mask", &len);
> + if (prop && len == sizeof(u32))
> + pdata->over_temperature_mask = be32_to_cpu(prop[0]);
> + prop = of_get_property(node, "resistance-cancellation", &len);
> + if (prop) {
> + if (len == sizeof(u32))
> + pdata->resistance_cancellation = be32_to_cpu(prop[0]);
> + else
> + pdata->resistance_cancellation = 0xff;
> + }
> + prop = of_get_property(node, "transistor-ideality", &len);
> + if (prop && len == 2 * sizeof(u32)) {
> + pdata->ideality_mask = be32_to_cpu(prop[0]);
> + pdata->ideality_value = be32_to_cpu(prop[1]);
> + }
> +}
> +
> +static int max6697_init_chip(struct i2c_client *client)
> +{
> + struct max6697_data *data = i2c_get_clientdata(client);
> + struct max6697_platform_data *pdata = dev_get_platdata(&client->dev);
> + struct max6697_platform_data p;
> + int ret;
> + u8 reg;
> +
> + /*
> + * Don't touch configuration if neither platform data nor of
Uppercase "OF" would be easier to parse, methinks.
> + * configuration was specified.
> + */
> + if (!pdata && !client->dev.of_node)
> + return 0;
> +
> + if (!pdata || client->dev.of_node) {
A comment of what you're testing here would be helpful. Does platform
take precedence over OF data, or the other way around? In fact the test
seems wrong, as the second half will always be true if evaluated.
> + memset(&p, 0, sizeof(data));
Size looks wrong.
> + max6697_get_config_of(client->dev.of_node, &p);
> + pdata = &p;
> + }
> +
> + reg = 0;
> + if (pdata->smbus_timeout_disable)
> + reg |= MAX6697_CONF_TIMEOUT;
> + if (pdata->extended_range_enable && data->type == max6581)
> + reg |= MAX6581_CONF_EXTENDED;
> + if (pdata->resistance_cancellation && data->type != max6581)
> + reg |= MAX6697_CONF_RESISTANCE;
> +
> + ret = i2c_smbus_write_byte_data(client, MAX6697_REG_CONFIG, reg);
> + if (ret < 0)
> + return ret;
You should never do this. If you want to modify specific bits of a
register, read it first, modify and write back. Don't arbitrarily set
the other bits to 0.
> +
> + ret = i2c_smbus_write_byte_data(client, MAX6697_REG_ALERT_MASK,
> + pdata->alert_mask);
> + if (ret < 0)
> + return ret;
> +
> + ret = i2c_smbus_write_byte_data(client, MAX6697_REG_OVERT_MASK,
> + pdata->over_temperature_mask);
> + if (ret < 0)
> + return ret;
> +
> + if (data->type == max6581) {
> + ret = i2c_smbus_write_byte_data(client, MAX6581_REG_RESISTANCE,
> + pdata->resistance_cancellation);
> + if (ret < 0)
> + return ret;
> + ret = i2c_smbus_write_byte_data(client, MAX6581_REG_IDEALITY,
> + pdata->ideality_mask);
> + if (ret < 0)
> + return ret;
> + ret = i2c_smbus_write_byte_data(client,
> + MAX6581_REG_IDEALITY_SELECT,
> + pdata->ideality_value);
> + if (ret < 0)
> + return ret;
> + }
> + return ret;
ret can only be 0 at this point.
> +}
> +
> +static int max6697_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct i2c_adapter *adapter = client->adapter;
> + struct device *dev = &client->dev;
> + struct max6697_data *data;
> + int i, err;
> +
> + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
> + return -ENODEV;
> +
> + data = devm_kzalloc(dev, sizeof(struct max6697_data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + data->type = id->driver_data;
> + data->chip = &max6697_chip_data[data->type];
> +
> + i2c_set_clientdata(client, data);
> + mutex_init(&data->update_lock);
> +
> + err = max6697_init_chip(client);
> + if (err)
> + return err;
> +
> + /* Register sysfs hooks */
> +
> + for (i = 0; i < data->chip->channels; i++) {
> + err = sysfs_create_file(&dev->kobj,
> + max6697_attributes[i * 6]);
> + if (err)
> + goto error;
> + err = sysfs_create_file(&dev->kobj,
> + max6697_attributes[i * 6 + 1]);
> + if (err)
> + goto error;
> + err = sysfs_create_file(&dev->kobj,
> + max6697_attributes[i * 6 + 2]);
> + if (err)
> + goto error;
> +
> + if (data->chip->have_crit & (1 << i)) {
> + err = sysfs_create_file(&dev->kobj,
> + max6697_attributes[i * 6 + 3]);
> + if (err)
> + goto error;
> + err = sysfs_create_file(&dev->kobj,
> + max6697_attributes[i * 6 + 4]);
> + if (err)
> + goto error;
> + }
> + if (data->chip->have_fault & (1 << i)) {
> + err = sysfs_create_file(&dev->kobj,
> + max6697_attributes[i * 6 + 5]);
> + if (err)
> + goto error;
> + }
> + }
These computed offsets into max6697_attributes feel very fragile. A
two-dimensional array would be more robust, although I agree removal
would then be slightly more costly. At the very least you should add a
comment where max6697_attributes is defined, that it is later accessed
by offset so great care should be taken before touching it in any way.
> +
> + data->hwmon_dev = hwmon_device_register(dev);
> + if (IS_ERR(data->hwmon_dev)) {
> + err = PTR_ERR(data->hwmon_dev);
> + goto error;
> + }
> +
> + return 0;
> +
> +error:
> + sysfs_remove_group(&dev->kobj, &max6697_group);
> + return err;
> +}
> +
> +static int max6697_remove(struct i2c_client *client)
> +{
> + struct max6697_data *data = i2c_get_clientdata(client);
> +
> + hwmon_device_unregister(data->hwmon_dev);
> + sysfs_remove_group(&client->dev.kobj, &max6697_group);
> +
> + return 0;
> +}
> +
> +static const struct i2c_device_id max6697_id[] = {
> + { "max6581", max6581 },
> + { "max6602", max6602 },
> + { "max6622", max6622 },
> + { "max6636", max6636 },
> + { "max6689", max6689 },
> + { "max6693", max6693 },
> + { "max6694", max6694 },
> + { "max6697", max6697 },
> + { "max6698", max6698 },
> + { "max6699", max6699 },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, max6697_id);
> +
> +/* This is the driver that will be inserted */
An old comment copied from driver to driver since 1999, with very
little value IMHO ;)
> +static struct i2c_driver max6697_driver = {
> + .class = I2C_CLASS_HWMON,
> + .driver = {
> + .name = "max6697",
> + },
Discussable indentation.
> + .probe = max6697_probe,
> + .remove = max6697_remove,
> + .id_table = max6697_id,
> +};
> +
> +module_i2c_driver(max6697_driver);
> +
> +MODULE_AUTHOR("Guenter Roeck <linux@xxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("MAX6697 temperature sensor driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/platform_data/max6697.h b/include/linux/platform_data/max6697.h
> new file mode 100644
> index 0000000..5a21b9b
> --- /dev/null
> +++ b/include/linux/platform_data/max6697.h
> @@ -0,0 +1,25 @@
> +/*
> + * max6697.h
> + * Copyright (c) 2012 Guenter Roeck <linux@xxxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#ifndef MAX6697_H
> +#define MAX6697_H
You should include <linux/types.h>, otherwise types bool and u8 used
below may not be defined.
> +
> +#define MAX6697_MAX_CONFIG_REG 8
What is this supposed to be used for?
> +
> +struct max6697_platform_data {
> + bool smbus_timeout_disable;
> + bool extended_range_enable;
> + u8 alert_mask;
> + u8 over_temperature_mask;
> + u8 resistance_cancellation;
> + u8 ideality_mask;
> + u8 ideality_value;
> +};
> +
> +#endif /* MAX6697_H */
--
Jean Delvare
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