* Re: [PATCH v4] hwmon: max6650: add thermal cooling device capability
@ 2019-04-19 13:15 Guenter Roeck
2019-04-19 13:40 ` Guenter Roeck
0 siblings, 1 reply; 4+ messages in thread
From: Guenter Roeck @ 2019-04-19 13:15 UTC (permalink / raw)
To: Jean-Francois Dagenais; +Cc: linux-hwmon, jdelvare
On Thu, Apr 18, 2019 at 08:57:22PM -0400, Jean-Francois Dagenais wrote:
> This allows max6650 devices to be referenced in dts as a cooling device.
>
> The pwm value seems duplicated in cooling_dev_state but since pwm goes
> through rounding logic into data->dac, it is modified and messes with
> the thermal zone state algorithms. It's also better to serve a cache
> value, thus avoiding periodic actual i2c traffic.
>
> Signed-off-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Looking into this more closely, I notice that it has a substantial downside:
It only registers one channel with the thermal subsystem. That is ok for
max6650, but it is a problem for max6651. There, it only registers a single
channel. Worse, extending it later would be difficult since the single-channel
support implies that the thermal data in the dts file would (probably) have to
look completely different for multi-channel support.
How does your proposed dts file look like ? Can we possibly adjust it to work
with multiple channels (ie with all channels of max6651) ?
Thanks,
Guenter
> ---
> Changes in v2:
> - Removed left-over debug printk.
> Changes in v3:
> - Add missing dependency in Kconfig
> Changes in v4:
> - Remove useless comment "thermal cooling device callbacks"
> - fix max6650_set_cur_state signature declaration style
> - Only warn when thermal_of_cooling_device_register fails
>
> drivers/hwmon/Kconfig | 1 +
> drivers/hwmon/max6650.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 90 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index d0f1dfe2bcbb..46d69fcdd48b 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -898,6 +898,7 @@ config SENSORS_MAX6642
> config SENSORS_MAX6650
> tristate "Maxim MAX6650 sensor chip"
> depends on I2C
> + depends on THERMAL || THERMAL=n
> help
> If you say yes here you get support for the MAX6650 / MAX6651
> sensor chips.
> diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c
> index 61135a2d0cff..137395ea5e95 100644
> --- a/drivers/hwmon/max6650.c
> +++ b/drivers/hwmon/max6650.c
> @@ -40,6 +40,7 @@
> #include <linux/hwmon-sysfs.h>
> #include <linux/err.h>
> #include <linux/of_device.h>
> +#include <linux/thermal.h>
>
> /*
> * Insmod parameters
> @@ -113,6 +114,7 @@ module_param(clock, int, 0444);
> struct max6650_data {
> struct i2c_client *client;
> const struct attribute_group *groups[3];
> + struct thermal_cooling_device *cooling_dev;
> struct mutex update_lock;
> int nr_fans;
> char valid; /* zero until following fields are valid */
> @@ -125,6 +127,7 @@ struct max6650_data {
> u8 count;
> u8 dac;
> u8 alarm;
> + unsigned long cooling_dev_state;
> };
>
> static const u8 tach_reg[] = {
> @@ -694,6 +697,63 @@ static int max6650_init_client(struct max6650_data *data,
> return 0;
> }
>
> +#if IS_ENABLED(CONFIG_THERMAL)
> +
> +static int max6650_get_max_state(struct thermal_cooling_device *cdev,
> + unsigned long *state)
> +{
> + *state = 255;
> +
> + return 0;
> +}
> +
> +static int max6650_get_cur_state(struct thermal_cooling_device *cdev,
> + unsigned long *state)
> +{
> + struct max6650_data *data = cdev->devdata;
> +
> + *state = data->cooling_dev_state;
> +
> + return 0;
> +}
> +
> +static int max6650_set_cur_state(struct thermal_cooling_device *cdev,
> + unsigned long state)
> +{
> + struct max6650_data *data = cdev->devdata;
> + struct i2c_client *client = data->client;
> + int err;
> +
> + state = clamp_val(state, 0, 255);
> +
> + mutex_lock(&data->update_lock);
> +
> + if (data->config & MAX6650_CFG_V12)
> + data->dac = 180 - (180 * state)/255;
> + else
> + data->dac = 76 - (76 * state)/255;
> +
> + err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac);
> +
> + if (!err) {
> + max6650_set_operating_mode(data, state ?
> + MAX6650_CFG_MODE_OPEN_LOOP :
> + MAX6650_CFG_MODE_OFF);
> + data->cooling_dev_state = state;
> + }
> +
> + mutex_unlock(&data->update_lock);
> +
> + return err < 0 ? err : 0;
> +}
> +
> +static const struct thermal_cooling_device_ops max6650_cooling_ops = {
> + .get_max_state = max6650_get_max_state,
> + .get_cur_state = max6650_get_cur_state,
> + .set_cur_state = max6650_set_cur_state,
> +};
> +#endif
> +
> static int max6650_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> @@ -709,6 +769,7 @@ static int max6650_probe(struct i2c_client *client,
> return -ENOMEM;
>
> data->client = client;
> + i2c_set_clientdata(client, data);
> mutex_init(&data->update_lock);
> data->nr_fans = of_id ? (int)(uintptr_t)of_id->data : id->driver_data;
>
> @@ -727,7 +788,33 @@ static int max6650_probe(struct i2c_client *client,
> hwmon_dev = devm_hwmon_device_register_with_groups(dev,
> client->name, data,
> data->groups);
> - return PTR_ERR_OR_ZERO(hwmon_dev);
> + err = PTR_ERR_OR_ZERO(hwmon_dev);
> + if (err)
> + return err;
> +
> +#if IS_ENABLED(CONFIG_THERMAL)
> + data->cooling_dev =
> + thermal_of_cooling_device_register(client->dev.of_node,
> + id->name, data,
> + &max6650_cooling_ops);
> + if (IS_ERR(data->cooling_dev))
> + dev_warn(&client->dev,
> + "thermal cooling device register failed: %d\n",
> + PTR_ERR(data->cooling_dev));
> + else
> + thermal_cdev_update(data->cooling_dev);
> +#endif
> + return 0;
> +}
> +
> +static int max6650_remove(struct i2c_client *client)
> +{
> + struct max6650_data *data = i2c_get_clientdata(client);
> +
> + if (!IS_ERR(data->cooling_dev))
> + thermal_cooling_device_unregister(data->cooling_dev);
> +
> + return 0;
> }
>
> static const struct i2c_device_id max6650_id[] = {
> @@ -743,6 +830,7 @@ static struct i2c_driver max6650_driver = {
> .of_match_table = of_match_ptr(max6650_dt_match),
> },
> .probe = max6650_probe,
> + .remove = max6650_remove,
> .id_table = max6650_id,
> };
>
> --
> 2.11.0
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v4] hwmon: max6650: add thermal cooling device capability
2019-04-19 13:15 [PATCH v4] hwmon: max6650: add thermal cooling device capability Guenter Roeck
@ 2019-04-19 13:40 ` Guenter Roeck
2019-04-20 2:44 ` Jean-Francois Dagenais
0 siblings, 1 reply; 4+ messages in thread
From: Guenter Roeck @ 2019-04-19 13:40 UTC (permalink / raw)
To: Jean-Francois Dagenais; +Cc: linux-hwmon, jdelvare
On Fri, Apr 19, 2019 at 06:15:20AM -0700, Guenter Roeck wrote:
> On Thu, Apr 18, 2019 at 08:57:22PM -0400, Jean-Francois Dagenais wrote:
> > This allows max6650 devices to be referenced in dts as a cooling device.
> >
> > The pwm value seems duplicated in cooling_dev_state but since pwm goes
> > through rounding logic into data->dac, it is modified and messes with
> > the thermal zone state algorithms. It's also better to serve a cache
> > value, thus avoiding periodic actual i2c traffic.
> >
> > Signed-off-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
>
> Looking into this more closely, I notice that it has a substantial downside:
> It only registers one channel with the thermal subsystem. That is ok for
> max6650, but it is a problem for max6651. There, it only registers a single
> channel. Worse, extending it later would be difficult since the single-channel
> support implies that the thermal data in the dts file would (probably) have to
> look completely different for multi-channel support.
>
> How does your proposed dts file look like ? Can we possibly adjust it to work
> with multiple channels (ie with all channels of max6651) ?
>
Never mind, I am talking nonsense. The max6651 has 4 tachometer input channels,
but only one pwm channel. Sorry for the noise. I'll apply your patch.
Can you send me a register dump for the chip (from i2cdump) ?
Thanks,
Guenter
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v4] hwmon: max6650: add thermal cooling device capability
2019-04-19 13:40 ` Guenter Roeck
@ 2019-04-20 2:44 ` Jean-Francois Dagenais
0 siblings, 0 replies; 4+ messages in thread
From: Jean-Francois Dagenais @ 2019-04-20 2:44 UTC (permalink / raw)
To: Guenter Roeck; +Cc: linux-hwmon, jdelvare
> On Apr 19, 2019, at 09:40, Guenter Roeck <linux@roeck-us.net> wrote:
>
> Can you send me a register dump for the chip (from i2cdump) ?
Here you go...
~# i2cdump -f -r 0x0-0x16 -y 0 0x1b b
0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
00: 00 00 12 12 ff ff ff ff 00 00 00 00 01 01 01 01 ..??........????
10: 01 01 01 01 1f 1f 02 ???????
Our board has the max6650 and doesn't have the tach line connected.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v4] hwmon: max6650: add thermal cooling device capability
2019-04-18 22:02 [PATCH v2] " Guenter Roeck
@ 2019-04-19 0:57 ` Jean-Francois Dagenais
0 siblings, 0 replies; 4+ messages in thread
From: Jean-Francois Dagenais @ 2019-04-19 0:57 UTC (permalink / raw)
To: linux-hwmon; +Cc: jdelvare, linux, Jean-Francois Dagenais
This allows max6650 devices to be referenced in dts as a cooling device.
The pwm value seems duplicated in cooling_dev_state but since pwm goes
through rounding logic into data->dac, it is modified and messes with
the thermal zone state algorithms. It's also better to serve a cache
value, thus avoiding periodic actual i2c traffic.
Signed-off-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
---
Changes in v2:
- Removed left-over debug printk.
Changes in v3:
- Add missing dependency in Kconfig
Changes in v4:
- Remove useless comment "thermal cooling device callbacks"
- fix max6650_set_cur_state signature declaration style
- Only warn when thermal_of_cooling_device_register fails
drivers/hwmon/Kconfig | 1 +
drivers/hwmon/max6650.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 90 insertions(+), 1 deletion(-)
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index d0f1dfe2bcbb..46d69fcdd48b 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -898,6 +898,7 @@ config SENSORS_MAX6642
config SENSORS_MAX6650
tristate "Maxim MAX6650 sensor chip"
depends on I2C
+ depends on THERMAL || THERMAL=n
help
If you say yes here you get support for the MAX6650 / MAX6651
sensor chips.
diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c
index 61135a2d0cff..137395ea5e95 100644
--- a/drivers/hwmon/max6650.c
+++ b/drivers/hwmon/max6650.c
@@ -40,6 +40,7 @@
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/of_device.h>
+#include <linux/thermal.h>
/*
* Insmod parameters
@@ -113,6 +114,7 @@ module_param(clock, int, 0444);
struct max6650_data {
struct i2c_client *client;
const struct attribute_group *groups[3];
+ struct thermal_cooling_device *cooling_dev;
struct mutex update_lock;
int nr_fans;
char valid; /* zero until following fields are valid */
@@ -125,6 +127,7 @@ struct max6650_data {
u8 count;
u8 dac;
u8 alarm;
+ unsigned long cooling_dev_state;
};
static const u8 tach_reg[] = {
@@ -694,6 +697,63 @@ static int max6650_init_client(struct max6650_data *data,
return 0;
}
+#if IS_ENABLED(CONFIG_THERMAL)
+
+static int max6650_get_max_state(struct thermal_cooling_device *cdev,
+ unsigned long *state)
+{
+ *state = 255;
+
+ return 0;
+}
+
+static int max6650_get_cur_state(struct thermal_cooling_device *cdev,
+ unsigned long *state)
+{
+ struct max6650_data *data = cdev->devdata;
+
+ *state = data->cooling_dev_state;
+
+ return 0;
+}
+
+static int max6650_set_cur_state(struct thermal_cooling_device *cdev,
+ unsigned long state)
+{
+ struct max6650_data *data = cdev->devdata;
+ struct i2c_client *client = data->client;
+ int err;
+
+ state = clamp_val(state, 0, 255);
+
+ mutex_lock(&data->update_lock);
+
+ if (data->config & MAX6650_CFG_V12)
+ data->dac = 180 - (180 * state)/255;
+ else
+ data->dac = 76 - (76 * state)/255;
+
+ err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac);
+
+ if (!err) {
+ max6650_set_operating_mode(data, state ?
+ MAX6650_CFG_MODE_OPEN_LOOP :
+ MAX6650_CFG_MODE_OFF);
+ data->cooling_dev_state = state;
+ }
+
+ mutex_unlock(&data->update_lock);
+
+ return err < 0 ? err : 0;
+}
+
+static const struct thermal_cooling_device_ops max6650_cooling_ops = {
+ .get_max_state = max6650_get_max_state,
+ .get_cur_state = max6650_get_cur_state,
+ .set_cur_state = max6650_set_cur_state,
+};
+#endif
+
static int max6650_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -709,6 +769,7 @@ static int max6650_probe(struct i2c_client *client,
return -ENOMEM;
data->client = client;
+ i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
data->nr_fans = of_id ? (int)(uintptr_t)of_id->data : id->driver_data;
@@ -727,7 +788,33 @@ static int max6650_probe(struct i2c_client *client,
hwmon_dev = devm_hwmon_device_register_with_groups(dev,
client->name, data,
data->groups);
- return PTR_ERR_OR_ZERO(hwmon_dev);
+ err = PTR_ERR_OR_ZERO(hwmon_dev);
+ if (err)
+ return err;
+
+#if IS_ENABLED(CONFIG_THERMAL)
+ data->cooling_dev =
+ thermal_of_cooling_device_register(client->dev.of_node,
+ id->name, data,
+ &max6650_cooling_ops);
+ if (IS_ERR(data->cooling_dev))
+ dev_warn(&client->dev,
+ "thermal cooling device register failed: %d\n",
+ PTR_ERR(data->cooling_dev));
+ else
+ thermal_cdev_update(data->cooling_dev);
+#endif
+ return 0;
+}
+
+static int max6650_remove(struct i2c_client *client)
+{
+ struct max6650_data *data = i2c_get_clientdata(client);
+
+ if (!IS_ERR(data->cooling_dev))
+ thermal_cooling_device_unregister(data->cooling_dev);
+
+ return 0;
}
static const struct i2c_device_id max6650_id[] = {
@@ -743,6 +830,7 @@ static struct i2c_driver max6650_driver = {
.of_match_table = of_match_ptr(max6650_dt_match),
},
.probe = max6650_probe,
+ .remove = max6650_remove,
.id_table = max6650_id,
};
--
2.11.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
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2019-04-19 13:15 [PATCH v4] hwmon: max6650: add thermal cooling device capability Guenter Roeck
2019-04-19 13:40 ` Guenter Roeck
2019-04-20 2:44 ` Jean-Francois Dagenais
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2019-04-18 22:02 [PATCH v2] " Guenter Roeck
2019-04-19 0:57 ` [PATCH v4] " Jean-Francois Dagenais
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