Re: [RFC PATCH 6/9] hwmon: (lm90) Register to the thermal framework

[Wei Ni <wni@nvidia.com>]

On 02/19/2013 01:22 PM, Alex Courbot wrote:
> On 02/18/2013 08:30 PM, Wei Ni wrote:
>> Register the remote sensor to the thermal framework.
>> It can support to show the temperature and read/write threshold.
>>
>> Signed-off-by: Wei Ni <wni@nvidia.com>
>> ---
>>   arch/arm/boot/dts/tegra30-cardhu.dtsi |    1 +
>>   drivers/hwmon/lm90.c                  |  182 ++++++++++++++++++++++++++++++++-
>>   2 files changed, 182 insertions(+), 1 deletion(-)
> 
> Making changes to a driver *and* a board file in the same patch? I think 
> this should be separated, and the board file change preferably squashed 
> with the first patch of this series, and moved right after this one.
> 
>>
>> diff --git a/arch/arm/boot/dts/tegra30-cardhu.dtsi b/arch/arm/boot/dts/tegra30-cardhu.dtsi
>> index 15ad1ad..3f6ab89 100644
>> --- a/arch/arm/boot/dts/tegra30-cardhu.dtsi
>> +++ b/arch/arm/boot/dts/tegra30-cardhu.dtsi
>> @@ -279,6 +279,7 @@
>>   			reg = <0x4c>;
>>   			interrupt-parent = <&gpio>;
>>   			interrupts = <226 0x08>; /* gpio PCC2 */
>> +			#sensor-cells = <1>;
>>   		};
>>   	};
>>
>> diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
>> index de5a476..0abdedc 100644
>> --- a/drivers/hwmon/lm90.c
>> +++ b/drivers/hwmon/lm90.c
>> @@ -91,6 +91,7 @@
>>   #include <linux/sysfs.h>
>>   #include <linux/interrupt.h>
>>   #include <linux/of_irq.h>
>> +#include <linux/thermal.h>
>>
>>   /*
>>    * Addresses to scan
>> @@ -182,6 +183,15 @@ enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
>>   #define LM90_HAVE_BROKEN_ALERT	(1 << 7) /* Broken alert		*/
>>
>>   /*
>> + * Thermal framework
>> + */
>> +enum lm90_thresholds {
>> +	LM90_LOW_THRESHOLDS = 0,	/* threshold 0: low limits */
>> +	LM90_HIGH_THRESHOLDS,		/* threshold 1: high limits */
>> +	LM90_NUM_THRESHOLDS
>> +};
>> +
>> +/*
>>    * Driver data (common to all clients)
>>    */
>>
>> @@ -377,6 +387,9 @@ struct lm90_data {
>>   	s16 temp11[TEMP11_REG_NUM];
>>   	u8 temp_hyst;
>>   	u16 alarms; /* bitvector (upper 8 bits for max6695/96) */
>> +
>> +	struct thermal_sensor *ts_remote;
>> +	struct thermal_sensor *ts_local;
>>   };
>>
>>   /*
>> @@ -1493,12 +1506,151 @@ static irqreturn_t lm90_irq(int irq, void *dev_id)
>>   	return IRQ_HANDLED;
>>   }
>>
>> +static int lm90_read_remote_temp(struct thermal_sensor *ts, long *temp)
>> +{
>> +	struct i2c_client *client = ts->devdata;
>> +	struct device *dev = &client->dev;
>> +
>> +	_show_temp11(dev, TEMP11_REMOTE_TEMP, (int *)temp);
> 
> As Guenter pointed, this might break. Since you introduced _show_temp11 
> in a previous patch, you should revise it to take a long * as third 
> argument (or even better, return a long). Or if you cannot do that for 
> some reason, use a temporary int and affect temp properly (*temp = 
> temp_int).

yes, the pointer will cause problems here.
I will follow Guenter suggestion to return the value simply for
_show_temp11 and _show_temp8

> 
>> +
>> +	return 0;
>> +}
>> +
>> +static int lm90_read_remote_threshold(struct thermal_sensor *ts, int th_index,
>> +					long *val)
>> +{
>> +	struct i2c_client *client = ts->devdata;
>> +	struct device *dev = &client->dev;
>> +	int index;
>> +
>> +	switch (th_index) {
>> +	case LM90_LOW_THRESHOLDS:
>> +		/* remote low limit */
>> +		index = TEMP11_REMOTE_LOW;
>> +		break;
>> +	case LM90_HIGH_THRESHOLDS:
>> +		/* remote high limit */
>> +		index = TEMP11_REMOTE_HIGH;
>> +		break;
>> +	default:
>> +		dev_err(dev, "read remote threshold failed.\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	_show_temp11(dev, index, (int *)val);
>> +
>> +	return 0;
>> +}
>> +
>> +static int lm90_write_remote_threshold(struct thermal_sensor *ts, int th_index,
>> +					long val)
>> +{
>> +	struct i2c_client *client = ts->devdata;
>> +	struct device *dev = &client->dev;
>> +	int nr, index;
>> +
>> +	switch (th_index) {
>> +	case LM90_LOW_THRESHOLDS:
>> +		/* remote low limit */
>> +		nr = NR_CHAN_0_REMOTE_LOW;
>> +		index = TEMP11_REMOTE_LOW;
>> +		break;
>> +	case LM90_HIGH_THRESHOLDS:
>> +		/* remote high limit */
>> +		nr = NR_CHAN_0_REMOTE_HIGH;
>> +		index = TEMP11_REMOTE_HIGH;
>> +		break;
>> +	default:
>> +		dev_err(dev, "write remote threshold failed.\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	_set_temp11(dev, nr, index, val);
>> +
>> +	return 0;
>> +}
>> +
>> +static struct thermal_sensor_ops remote_ops = {
>> +	.get_temp = lm90_read_remote_temp,
>> +	.get_threshold = lm90_read_remote_threshold,
>> +	.set_threshold = lm90_write_remote_threshold,
>> +};
>> +
>> +static int lm90_read_local_temp(struct thermal_sensor *ts, long *temp)
>> +{
>> +	struct i2c_client *client = ts->devdata;
>> +	struct device *dev = &client->dev;
>> +
>> +	_show_temp11(dev, TEMP11_LOCAL_TEMP, (int *)temp);
>> +
>> +	return 0;
>> +}
>> +
>> +static int lm90_read_local_threshold(struct thermal_sensor *ts, int th_index,
>> +					long *val)
>> +{
>> +	struct i2c_client *client = ts->devdata;
>> +	struct device *dev = &client->dev;
>> +	int index;
>> +
>> +	switch (th_index) {
>> +	case LM90_LOW_THRESHOLDS:
>> +		/* local low limit */
>> +		index = TEMP8_LOCAL_LOW;
>> +		break;
>> +	case LM90_HIGH_THRESHOLDS:
>> +		/* local high limit */
>> +		index = TEMP8_LOCAL_HIGH;
>> +		break;
> 
> I think the comments are unneeded here, the macro name should be 
> explicit enough.

OK.

> 
>> +	default:
>> +		dev_err(dev, "read local threshold failed.\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	_show_temp8(dev, index, (int *)val);
>> +
>> +	return 0;
>> +}
>> +
>> +static int lm90_write_local_threshold(struct thermal_sensor *ts, int th_index,
>> +					long val)
>> +{
>> +	struct i2c_client *client = ts->devdata;
>> +	struct device *dev = &client->dev;
>> +	int index;
>> +
>> +	switch (th_index) {
>> +	case LM90_LOW_THRESHOLDS:
>> +		/* local low limit */
>> +		index = TEMP8_LOCAL_LOW;
>> +		break;
>> +	case LM90_HIGH_THRESHOLDS:
>> +		/* local high limit */
>> +		index = TEMP8_LOCAL_HIGH;
>> +		break;
>> +	default:
>> +		dev_err(dev, "write local threshold failed.\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	_set_temp8(dev, index, val);
>> +
>> +	return 0;
>> +}
>> +
>> +static struct thermal_sensor_ops local_ops = {
>> +	.get_temp = lm90_read_local_temp,
>> +	.get_threshold = lm90_read_local_threshold,
>> +	.set_threshold = lm90_write_local_threshold,
>> +};
>> +
>>   static int lm90_probe(struct i2c_client *client,
>>   		      const struct i2c_device_id *id)
>>   {
>>   	struct device *dev = &client->dev;
>>   	struct i2c_adapter *adapter = to_i2c_adapter(dev->parent);
>>   	struct lm90_data *data;
>> +	struct node_args np_args;
>>   	int err;
>>
>>   	data = devm_kzalloc(&client->dev, sizeof(struct lm90_data), GFP_KERNEL);
>> @@ -1576,12 +1728,38 @@ static int lm90_probe(struct i2c_client *client,
>>   				       "lm90", data);
>>   		if (err < 0) {
>>   			dev_err(dev, "cannot request interrupt\n");
>> -			goto exit_remove_files;
>> +			goto exit_unregister_hwmon;
>>   		}
>>   	}
>>
>> +	np_args.np = dev->of_node;
>> +	np_args.index = 0;
>> +	data->ts_remote = thermal_sensor_register("lm90_remote",
>> +						LM90_NUM_THRESHOLDS,
>> +						&np_args,
>> +						&remote_ops, client);
>> +	if (IS_ERR(data->ts_remote)) {
>> +		dev_err(dev, "cannot register sensor to thermal framework\n");
>> +		err = -EINVAL;
> 
> When don't you return the error code provided by 
> thermal_sensor_register, e.g. err = PTR_ERR(data->ts_remote) ?

I didn't consider it, I will change it.

> 
>> +		goto exit_unregister_hwmon;
>> +	}
>> +
>> +	np_args.index = 1;
>> +	data->ts_local = thermal_sensor_register("lm90_local",
>> +						LM90_NUM_THRESHOLDS,
>> +						&np_args,
>> +						&local_ops, client);
>> +
>> +	if (IS_ERR(data->ts_local)) {
>> +		dev_err(dev, "cannot register sensor to thermal framework\n");
>> +		err = -EINVAL;
> 
> Same thing here.
> 
>> +		goto exit_unregister_hwmon;
>> +	}
>> +
>>   	return 0;
>>
>> +exit_unregister_hwmon:
>> +	hwmon_device_unregister(data->hwmon_dev);
>>   exit_remove_files:
>>   	lm90_remove_files(client, data);
>>   exit_restore:
>> @@ -1594,6 +1772,8 @@ static int lm90_remove(struct i2c_client *client)
>>   	struct lm90_data *data = i2c_get_clientdata(client);
>>
>>   	free_irq(client->irq, data);
>> +	thermal_sensor_unregister(data->ts_remote);
>> +	thermal_sensor_unregister(data->ts_local);
> 
> Ideally you would unregister your sensors in the reverse order they have 
> been registered, but I'm being picky here.

Yes, it's better in reverse order.
I really appreciate you reviewing my patches so carefully :)

Wei.

> 
> Alex.
>