Re: [PATCH v7 2/2] hwmon: (nct7802) Make temperature/voltage sensors configurable

Guenter Roeck
2021-10-11T04:09:05Z

On 10/10/21 6:53 PM, Oskar Senft wrote:
> I wasn't sure if submitting JUST a v7 of nuvoton,nct7802.yaml (i.e.
> the 1/2 in this series) would be the right thing to do and thought it
> would be easier to follow if I dropped both. I couldn't find
> documentation on what's the right thing to do in that case. Would it
> have been better to only submit nuvoton,nct7802.yaml as "PATCH v7" ?
>

First, please don't top-post.

Second, no, submitting both patches was the right thing to do, but
you should not drop a Reviewed-by: tag if there was no change to
the patch.

Guenter

> Oskar.
>
> On Sun, Oct 10, 2021 at 9:49 PM Guenter Roeck <linux@roeck-us.net> wrote:
>>
>> On 10/10/21 6:22 PM, Oskar Senft wrote:
>>> This change allows LTD and RTD inputs to be configured via
>>> device tree bindings. If the DT bindings are not present or
>>> invalid, the input configuration is not modified and left at
>>> HW defaults.
>>>
>>> Signed-off-by: Oskar Senft <osk@google.com>
>>
>> I sent a Reviewed-by: for v6 of this patch.
>>
>>> ---
>>> Changes from PATCH v6:
>>> - None (resubmitted due to changes in nuvoton,nct7802.yaml).
>>>
>>
>> Why did you drop it if there was no change ?
>>
>> Guenter
>>
>>> Changes from PATCH v5:
>>> - Removed unused "found_channel_config" variable.
>>> - Initialize mode_mask and mode_val to defaults.
>>> ---
>>> drivers/hwmon/nct7802.c | 129 ++++++++++++++++++++++++++++++++++++++--
>>> 1 file changed, 125 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/hwmon/nct7802.c b/drivers/hwmon/nct7802.c
>>> index 604af2f6103a..d56f78327619 100644
>>> --- a/drivers/hwmon/nct7802.c
>>> +++ b/drivers/hwmon/nct7802.c
>>> @@ -51,6 +51,23 @@ static const u8 REG_VOLTAGE_LIMIT_MSB_SHIFT[2][5] = {
>>> #define REG_CHIP_ID 0xfe
>>> #define REG_VERSION_ID 0xff
>>>
>>> +/*
>>> + * Resistance temperature detector (RTD) modes according to 7.2.32 Mode
>>> + * Selection Register
>>> + */
>>> +#define RTD_MODE_CURRENT 0x1
>>> +#define RTD_MODE_THERMISTOR 0x2
>>> +#define RTD_MODE_VOLTAGE 0x3
>>> +
>>> +#define MODE_RTD_MASK 0x3
>>> +#define MODE_LTD_EN 0x40
>>> +
>>> +/*
>>> + * Bit offset for sensors modes in REG_MODE.
>>> + * Valid for index 0..2, indicating RTD1..3.
>>> + */
>>> +#define MODE_BIT_OFFSET_RTD(index) ((index) * 2)
>>> +
>>> /*
>>> * Data structures and manipulation thereof
>>> */
>>> @@ -1038,7 +1055,112 @@ static const struct regmap_config nct7802_regmap_config = {
>>> .volatile_reg = nct7802_regmap_is_volatile,
>>> };
>>>
>>> -static int nct7802_init_chip(struct nct7802_data *data)
>>> +static int nct7802_get_channel_config(struct device *dev,
>>> + struct device_node *node, u8 *mode_mask,
>>> + u8 *mode_val)
>>> +{
>>> + u32 reg;
>>> + const char *type_str, *md_str;
>>> + u8 md;
>>> +
>>> + if (!node->name || of_node_cmp(node->name, "channel"))
>>> + return 0;
>>> +
>>> + if (of_property_read_u32(node, "reg", &reg)) {
>>> + dev_err(dev, "Could not read reg value for '%s'\n",
>>> + node->full_name);
>>> + return -EINVAL;
>>> + }
>>> +
>>> + if (reg > 3) {
>>> + dev_err(dev, "Invalid reg (%u) in '%s'\n", reg,
>>> + node->full_name);
>>> + return -EINVAL;
>>> + }
>>> +
>>> + if (reg == 0) {
>>> + if (!of_device_is_available(node))
>>> + *mode_val &= ~MODE_LTD_EN;
>>> + else
>>> + *mode_val |= MODE_LTD_EN;
>>> + *mode_mask |= MODE_LTD_EN;
>>> + return 0;
>>> + }
>>> +
>>> + /* At this point we have reg >= 1 && reg <= 3 */
>>> +
>>> + if (!of_device_is_available(node)) {
>>> + *mode_val &= ~(MODE_RTD_MASK << MODE_BIT_OFFSET_RTD(reg - 1));
>>> + *mode_mask |= MODE_RTD_MASK << MODE_BIT_OFFSET_RTD(reg - 1);
>>> + return 0;
>>> + }
>>> +
>>> + if (of_property_read_string(node, "sensor-type", &type_str)) {
>>> + dev_err(dev, "No type for '%s'\n", node->full_name);
>>> + return -EINVAL;
>>> + }
>>> +
>>> + if (!strcmp(type_str, "voltage")) {
>>> + *mode_val |= (RTD_MODE_VOLTAGE & MODE_RTD_MASK)
>>> + << MODE_BIT_OFFSET_RTD(reg - 1);
>>> + *mode_mask |= MODE_RTD_MASK << MODE_BIT_OFFSET_RTD(reg - 1);
>>> + return 0;
>>> + }
>>> +
>>> + if (strcmp(type_str, "temperature")) {
>>> + dev_err(dev, "Invalid type '%s' for '%s'\n", type_str,
>>> + node->full_name);
>>> + return -EINVAL;
>>> + }
>>> +
>>> + if (reg == 3) {
>>> + /* RTD3 only supports thermistor mode */
>>> + md = RTD_MODE_THERMISTOR;
>>> + } else {
>>> + if (of_property_read_string(node, "temperature-mode",
>>> + &md_str)) {
>>> + dev_err(dev, "No mode for '%s'\n", node->full_name);
>>> + return -EINVAL;
>>> + }
>>> +
>>> + if (!strcmp(md_str, "thermal-diode"))
>>> + md = RTD_MODE_CURRENT;
>>> + else if (!strcmp(md_str, "thermistor"))
>>> + md = RTD_MODE_THERMISTOR;
>>> + else {
>>> + dev_err(dev, "Invalid mode '%s' for '%s'\n", md_str,
>>> + node->full_name);
>>> + return -EINVAL;
>>> + }
>>> + }
>>> +
>>> + *mode_val |= (md & MODE_RTD_MASK) << MODE_BIT_OFFSET_RTD(reg - 1);
>>> + *mode_mask |= MODE_RTD_MASK << MODE_BIT_OFFSET_RTD(reg - 1);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int nct7802_configure_channels(struct device *dev,
>>> + struct nct7802_data *data)
>>> +{
>>> + /* Enable local temperature sensor by default */
>>> + u8 mode_mask = MODE_LTD_EN, mode_val = MODE_LTD_EN;
>>> + struct device_node *node;
>>> + int err;
>>> +
>>> + if (dev->of_node) {
>>> + for_each_child_of_node(dev->of_node, node) {
>>> + err = nct7802_get_channel_config(dev, node, &mode_mask,
>>> + &mode_val);
>>> + if (err)
>>> + return err;
>>> + }
>>> + }
>>> +
>>> + return regmap_update_bits(data->regmap, REG_MODE, mode_mask, mode_val);
>>> +}
>>> +
>>> +static int nct7802_init_chip(struct device *dev, struct nct7802_data *data)
>>> {
>>> int err;
>>>
>>> @@ -1047,8 +1169,7 @@ static int nct7802_init_chip(struct nct7802_data *data)
>>> if (err)
>>> return err;
>>>
>>> - /* Enable local temperature sensor */
>>> - err = regmap_update_bits(data->regmap, REG_MODE, 0x40, 0x40);
>>> + err = nct7802_configure_channels(dev, data);
>>> if (err)
>>> return err;
>>>
>>> @@ -1074,7 +1195,7 @@ static int nct7802_probe(struct i2c_client *client)
>>> mutex_init(&data->access_lock);
>>> mutex_init(&data->in_alarm_lock);
>>>
>>> - ret = nct7802_init_chip(data);
>>> + ret = nct7802_init_chip(dev, data);
>>> if (ret < 0)
>>> return ret;
>>>
>>>
>>