Re: [PATCH 10/11] hwmon: Add Altera A10-SR power supply alarms

[Thor Thayer <tthayer@opensource.altera.com>]

On 04/25/2016 09:58 AM, Guenter Roeck wrote:
> On 04/25/2016 07:41 AM, Thor Thayer wrote:
>>
>>
>> On 04/22/2016 05:24 PM, Guenter Roeck wrote:
>>> On Fri, Apr 22, 2016 at 10:33:38AM -0500,
>>> tthayer@opensource.altera.com wrote:
>>>> From: Thor Thayer <tthayer@opensource.altera.com>
>>>>
>>>> This patch adds the power supply alarms of the hwmon framework
>>>> to the Arria10 System Resource chip.
>>>>
>>>> Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
>>>> ---
>>>
>>> Please read and follow Documentation/hwmon/sysfs-interface
>>> as well as Documentation/hwmon/submitting-patches. At the very least,
>>> you are expected to document your driver, and you are expected to
>>> use standard attribute names.
>>>
>>
>> OK. I misunderstood. The standard attribute names would be
>> power[1-*]_alarm and the binding documentation the a10sr-hwmon portion
>> for MFD doesn't cover this.
>>
>
> power ? Why power ? The names suggest those are voltages.
> Also not sure why those names would be in the bindings.
>
Yes, you are correct. I should be using in[0-*]_lcrit_alarm.

I didn't phrase my reply clearly. It was my initial understanding that 
the binding documentation for the MFD would cover the documentation for 
the driver. I missed that I needed to add the documentation into 
Documentation/hwmon/altera-a10sr-hwmon.c but I will fix this oversight.

Thanks.

>>>>   drivers/hwmon/Kconfig              |    9 ++
>>>>   drivers/hwmon/Makefile             |    1 +
>>>>   drivers/hwmon/altera-a10sr-hwmon.c |  215
>>>> ++++++++++++++++++++++++++++++++++++
>>>>   3 files changed, 225 insertions(+)
>>>>   create mode 100644 drivers/hwmon/altera-a10sr-hwmon.c
>>>>
>>>> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
>>>> index ff94007..af08846 100644
>>>> --- a/drivers/hwmon/Kconfig
>>>> +++ b/drivers/hwmon/Kconfig
>>>> @@ -248,6 +248,15 @@ config SENSORS_ADT7475
>>>>         This driver can also be build as a module.  If so, the module
>>>>         will be called adt7475.
>>>>
>>>> +config SENSORS_ALTERA_A10SR
>>>> +    bool "Altera Arria10 System Status"
>>>> +    depends on MFD_ALTERA_A10SR
>>>> +    help
>>>> +      If you say yes here you get support for the power ready status
>>>> +      for the Arria10's external power supplies on the Arria10 DevKit.
>>>> +      These values are read over the SPI bus from the Arria10 System
>>>> +      Resource chip.
>>>> +
>>>>   config SENSORS_ASC7621
>>>>       tristate "Andigilog aSC7621"
>>>>       depends on I2C
>>>> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
>>>> index 2ef5b7c..17d72a7 100644
>>>> --- a/drivers/hwmon/Makefile
>>>> +++ b/drivers/hwmon/Makefile
>>>> @@ -43,6 +43,7 @@ obj-$(CONFIG_SENSORS_ADT7411)    += adt7411.o
>>>>   obj-$(CONFIG_SENSORS_ADT7462)    += adt7462.o
>>>>   obj-$(CONFIG_SENSORS_ADT7470)    += adt7470.o
>>>>   obj-$(CONFIG_SENSORS_ADT7475)    += adt7475.o
>>>> +obj-$(CONFIG_SENSORS_ALTERA_A10SR) += altera-a10sr-hwmon.o
>>>>   obj-$(CONFIG_SENSORS_APPLESMC)    += applesmc.o
>>>>   obj-$(CONFIG_SENSORS_ARM_SCPI)    += scpi-hwmon.o
>>>>   obj-$(CONFIG_SENSORS_ASC7621)    += asc7621.o
>>>> diff --git a/drivers/hwmon/altera-a10sr-hwmon.c
>>>> b/drivers/hwmon/altera-a10sr-hwmon.c
>>>> new file mode 100644
>>>> index 0000000..1eecc6b
>>>> --- /dev/null
>>>> +++ b/drivers/hwmon/altera-a10sr-hwmon.c
>>>> @@ -0,0 +1,215 @@
>>>> +/*
>>>> + *  Copyright Altera Corporation (C) 2014-2016. All Rights Reserved
>>>> + *
>>>> + * This program is free software; you can redistribute it and/or
>>>> modify it
>>>> + * under the terms and conditions of the GNU General Public License,
>>>> + * version 2, as published by the Free Software Foundation.
>>>> + *
>>>> + * This program is distributed in the hope 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.
>>>> + *
>>>> + * You should have received a copy of the GNU General Public
>>>> License along with
>>>> + * this program.  If not, see <http://www.gnu.org/licenses/>.
>>>> + *
>>>> + * HW Monitor driver for  Altera Arria10 MAX5 System Resource Chip
>>>> + * Adapted from DA9052
>>>> + */
>>>> +
>>>> +#include <linux/hwmon.h>
>>>> +#include <linux/hwmon-sysfs.h>
>>>> +#include <linux/mfd/altera-a10sr.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/of.h>
>>>
>>> Please list include files in alphabetic order.
>>>
>>
>> OK. I thought this was in alphabetical order. I'll update this after
>> figuring out where I was wrong.
>>
>
> Sorry, PBKAC on my side.
>
> Guenter
>
>>>> +
>>>> +#define ALTR_A10SR_1V0_BIT_POS          ALTR_A10SR_PG1_1V0_SHIFT
>>>> +#define ALTR_A10SR_0V95_BIT_POS         ALTR_A10SR_PG1_0V95_SHIFT
>>>> +#define ALTR_A10SR_0V9_BIT_POS          ALTR_A10SR_PG1_0V9_SHIFT
>>>> +#define ALTR_A10SR_10V_BIT_POS          ALTR_A10SR_PG1_10V_SHIFT
>>>> +#define ALTR_A10SR_5V0_BIT_POS          ALTR_A10SR_PG1_5V0_SHIFT
>>>> +#define ALTR_A10SR_3V3_BIT_POS          ALTR_A10SR_PG1_3V3_SHIFT
>>>> +#define ALTR_A10SR_2V5_BIT_POS          ALTR_A10SR_PG1_2V5_SHIFT
>>>> +#define ALTR_A10SR_1V8_BIT_POS          ALTR_A10SR_PG1_1V8_SHIFT
>>>> +#define ALTR_A10SR_OP_FLAG_BIT_POS      ALTR_A10SR_PG1_OP_FLAG_SHIFT
>>>> +/* 2nd register needs an offset of 8 to get to 2nd register */
>>>> +#define ALTR_A10SR_FBC2MP_BIT_POS       (8 +
>>>> ALTR_A10SR_PG2_FBC2MP_SHIFT)
>>>> +#define ALTR_A10SR_FAC2MP_BIT_POS       (8 +
>>>> ALTR_A10SR_PG2_FAC2MP_SHIFT)
>>>> +#define ALTR_A10SR_FMCBVADJ_BIT_POS     (8 +
>>>> ALTR_A10SR_PG2_FMCBVADJ_SHIFT)
>>>> +#define ALTR_A10SR_FMCAVADJ_BIT_POS     (8 +
>>>> ALTR_A10SR_PG2_FMCAVADJ_SHIFT)
>>>> +#define ALTR_A10SR_HL_VDDQ_BIT_POS      (8 +
>>>> ALTR_A10SR_PG2_HL_VDDQ_SHIFT)
>>>> +#define ALTR_A10SR_HL_VDD_BIT_POS       (8 +
>>>> ALTR_A10SR_PG2_HL_VDD_SHIFT)
>>>> +#define ALTR_A10SR_HL_HPS_BIT_POS       (8 +
>>>> ALTR_A10SR_PG2_HL_HPS_SHIFT)
>>>> +#define ALTR_A10SR_HPS_BIT_POS          (8 + ALTR_A10SR_PG2_HPS_SHIFT)
>>>> +/* 3rd register needs an offset of 16 to get to 3rd register */
>>>> +#define ALTR_A10SR_10V_FAIL_BIT_POS     (16 +
>>>> ALTR_A10SR_PG3_10V_FAIL_SHIFT)
>>>> +#define ALTR_A10SR_FAM2C_BIT_POS        (16 +
>>>> ALTR_A10SR_PG3_FAM2C_SHIFT)
>>>> +
>>>> +/**
>>>> + * struct altr_a10sr_hwmon - Altera Max5 HWMON device private data
>>>> structure
>>>> + * @device: hwmon class.
>>>> + * @regmap: the regmap from the parent device.
>>>> + */
>>>> +struct altr_a10sr_hwmon {
>>>> +    struct device        *class_device;
>>>> +    struct regmap        *regmap;
>>>> +};
>>>> +
>>>> +static ssize_t altr_a10sr_read_status(struct device *dev,
>>>> +                      struct device_attribute *devattr,
>>>> +                      char *buf)
>>>> +{
>>>> +    struct altr_a10sr_hwmon *hwmon = dev_get_drvdata(dev);
>>>> +    int val, ret, index = to_sensor_dev_attr(devattr)->index;
>>>> +    int mask = ALTR_A10SR_REG_BIT_MASK(index);
>>>> +    unsigned char reg = ALTR_A10SR_PWR_GOOD1_REG +
>>>> +                ALTR_A10SR_REG_OFFSET(index);
>>>> +
>>>> +    ret = regmap_read(hwmon->regmap, reg, &val);
>>>
>>> The pointer parameter to regmap_read() is unsigned int. I would suggest
>>> to use the same variable type to avoid surprises.
>>>
>> Understood. Thanks.
>>
>>>> +    if (ret < 0)
>>>> +        return ret;
>>>> +
>>>> +    return sprintf(buf, "%d\n", !!(~val & mask));
>>>
>>> Are alarms all active low ?
>>>
>> Yes, They are actually Power Good signals (Good = high) so I'm inverting.
>>
>>>> +}
>>>> +
>>>> +static ssize_t altr_a10sr_hwmon_show_name(struct device *dev,
>>>> +                      struct device_attribute *devattr,
>>>> +                      char *buf)
>>>> +{
>>>> +    return sprintf(buf, "altr_a10sr\n");
>>>> +}
>>>> +
>>>> +/* First Power Good Register Bits */
>>>> +static SENSOR_DEVICE_ATTR(1v0_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_1V0_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(0v95_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_0V95_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(0v9_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_0V9_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(5v0_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_5V0_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(3v3_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_3V3_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(2v5_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_2V5_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(1v8_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_1V8_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(opflag_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_OP_FLAG_BIT_POS);
>>>> +/* Second Power Good Register Bits */
>>>> +static SENSOR_DEVICE_ATTR(fbc2mp_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_FBC2MP_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(fac2mp_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_FAC2MP_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(fmcbvadj_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_FMCBVADJ_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(fmcavadj_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_FMCAVADJ_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(hl_vddq_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_HL_VDDQ_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(hl_vdd_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_HL_VDD_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(hlhps_vdd_alarm, S_IRUGO,
>>>> altr_a10sr_read_status,
>>>> +              NULL, ALTR_A10SR_HL_HPS_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(hps_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_HPS_BIT_POS);
>>>> +/* Third Power Good Register Bits */
>>>> +static SENSOR_DEVICE_ATTR(10v_alarm, S_IRUGO, altr_a10sr_read_status,
>>>> +              NULL, ALTR_A10SR_10V_FAIL_BIT_POS);
>>>> +static SENSOR_DEVICE_ATTR(fam2c_alarm, S_IRUGO,
>>>> altr_a10sr_read_status, NULL,
>>>> +              ALTR_A10SR_FAM2C_BIT_POS);
>>>> +
>>>> +static DEVICE_ATTR(name, S_IRUGO, altr_a10sr_hwmon_show_name, NULL);
>>>> +
>>>> +static struct attribute *altr_a10sr_attr[] = {
>>>> +    &dev_attr_name.attr,
>>>> +    /* First Power Good Register */
>>>> +    &sensor_dev_attr_opflag_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_1v8_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_2v5_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_1v0_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_3v3_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_5v0_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_0v9_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_0v95_alarm.dev_attr.attr,
>>>> +    /* Second Power Good Register */
>>>> +    &sensor_dev_attr_hps_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_hlhps_vdd_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_hl_vdd_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_hl_vddq_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_fmcavadj_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_fmcbvadj_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_fac2mp_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_fbc2mp_alarm.dev_attr.attr,
>>>> +    /* Third Power Good Register */
>>>> +    &sensor_dev_attr_10v_alarm.dev_attr.attr,
>>>> +    &sensor_dev_attr_fam2c_alarm.dev_attr.attr,
>>>
>>> Ultimately, this doesn't really make much sense, even with standard
>>> attribute
>>> names. The ABI assumes that _input attrributes exist. Not sure if
>>> that could
>>> be solved by providing 'dummy' unreadable input attributes
>>> (permission 0);
>>> that might be worth a try. If you want to attach names to the
>>> attributes,
>>> you would need to provide label attributes. Specifically you would need
>>>
>>>     inX_input (with permission 0) - not sure if that is even possible
>>>     inX_alarm
>>>     inX_label
>>>
>> Hmm. OK. I may need to rethink this.
>>
>>>> +    NULL
>>>> +};
>>>> +
>>>> +static const struct attribute_group altr_a10sr_attr_group = {
>>>> +    .attrs = altr_a10sr_attr
>>>> +};
>>>> +
>>>> +static int altr_a10sr_hwmon_probe(struct platform_device *pdev)
>>>> +{
>>>> +    struct altr_a10sr_hwmon *hwmon;
>>>> +    int ret;
>>>> +    struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent);
>>>> +
>>>
>>> What if someone creates a stand-alone devicetree property for this
>>> driver,
>>> and there is no parent (or parent driver data) ?
>>>
>> I agree if this was a commercially available part. However, this is a
>> specific driver for a programmable logic device (PLD) that will always
>> be part of an MFD parent. The PLD only supports the Altera Development
>> Kit.
>>
>>>> +    hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL);
>>>> +    if (!hwmon)
>>>> +        return -ENOMEM;
>>>> +
>>>> +    hwmon->regmap = a10sr->regmap;
>>>> +
>>>> +    platform_set_drvdata(pdev, hwmon);
>>>> +
>>>> +    ret = sysfs_create_group(&pdev->dev.kobj, &altr_a10sr_attr_group);
>>>> +    if (ret)
>>>> +        goto err_mem;
>>>> +
>>>> +    hwmon->class_device = hwmon_device_register(&pdev->dev);
>>>> +    if (IS_ERR(hwmon->class_device)) {
>>>> +        ret = PTR_ERR(hwmon->class_device);
>>>> +        goto err_sysfs;
>>>> +    }
>>>
>>> Please use devm_hwmon_device_register_with_groups().
>>>
>> Understood. Thanks.
>>
>> Thanks for reviewing.
>>
>>>> +
>>>> +    return 0;
>>>> +
>>>> +err_sysfs:
>>>> +    sysfs_remove_group(&pdev->dev.kobj, &altr_a10sr_attr_group);
>>>> +err_mem:
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +static int altr_a10sr_hwmon_remove(struct platform_device *pdev)
>>>> +{
>>>> +    struct altr_a10sr_hwmon *hwmon = platform_get_drvdata(pdev);
>>>> +
>>>> +    hwmon_device_unregister(hwmon->class_device);
>>>> +    sysfs_remove_group(&pdev->dev.kobj, &altr_a10sr_attr_group);
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static const struct of_device_id altr_a10sr_hwmon_of_match[] = {
>>>> +    { .compatible = "altr,a10sr-hwmon" },
>>>> +    { },
>>>> +};
>>>> +MODULE_DEVICE_TABLE(of, altr_a10sr_hwmon_of_match);
>>>> +
>>>> +static struct platform_driver altr_a10sr_hwmon_driver = {
>>>> +    .probe = altr_a10sr_hwmon_probe,
>>>> +    .remove = altr_a10sr_hwmon_remove,
>>>> +    .driver = {
>>>> +        .name = "altr_a10sr_hwmon",
>>>> +        .of_match_table = of_match_ptr(altr_a10sr_hwmon_of_match),
>>>> +    },
>>>> +};
>>>> +
>>>> +module_platform_driver(altr_a10sr_hwmon_driver);
>>>> +
>>>> +MODULE_LICENSE("GPL v2");
>>>> +MODULE_AUTHOR("Thor Thayer <tthayer@opensource.altera.com>");
>>>> +MODULE_DESCRIPTION("HW Monitor driver for Altera Arria10 System
>>>> Resource Chip");
>>>> --
>>>> 1.7.9.5
>>>>
>>
>