Re: [lm-sensors] [PATCH] adt7473: New driver for Analog DevicesADT7473 sensor chip

From: Mark M. Hoffman
Date: Sun Feb 17 2008 - 15:13:31 EST


Hi Darrick:

Sorry this took forever for me to review. Just a few little things...

* Darrick J. Wong <djwong@xxxxxxxxxx> [2007-12-19 15:14:38 -0800]:
> This driver also had that funny alarm1/alarm2 thing; here's a revision
> of yesterday's patch with that straightened out.
> ---
> This driver reports voltage, temperature and fan sensor readings
> on an ADT7473 chip.
>
> Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> ---
>
> drivers/hwmon/Kconfig | 10
> drivers/hwmon/Makefile | 1
> drivers/hwmon/adt7473.c | 1161 +++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 1172 insertions(+), 0 deletions(-)
>

Documentation/hwmon/adt7473 would be nice.

> new file mode 100644
> index 0000000..5528d5c
> --- /dev/null
> +++ b/drivers/hwmon/adt7473.c
> @@ -0,0 +1,1161 @@

(snip)

> +/*
> + * On this chip, voltages are given as a count of steps between a minimum
> + * and maximum voltage, not a direct voltage.
> + */
> +static int volt_convert_table[][2] = {
> + {2997, 3},
> + {4395, 4},
> +};

That should be const.

(snip)

> +static ssize_t show_pwm_auto_temp(struct device *dev,
> + struct device_attribute *devattr,
> + char *buf)
> +{
> + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> + struct adt7473_data *data = adt7473_update_device(dev);
> + int bhvr = data->pwm_behavior[attr->index] >> ADT7473_PWM_BHVR_SHIFT;
> +
> + switch (bhvr) {
> + case 3:
> + case 4:
> + case 7:
> + return sprintf(buf, "0\n");
> + case 0:
> + case 1:
> + case 5:
> + case 6:
> + return sprintf(buf, "%d\n", bhvr + 1);
> + case 2:
> + return sprintf(buf, "4\n");
> + }
> + BUG();

Given ADT7473_PWM_BHVR_SHIFT is 5, this BUG() is obviously impossible.
But I guess it's not obvious to GCC.

(snip)

> +static int adt7473_attach_adapter(struct i2c_adapter *adapter)
> +{
> + /*
> + * Some NVIDIA cards have an adt7473 attached to the on-board
> + * i2c controller, but the i2c adapter driver in the binary
> + * nvidia superblob driver sets class to 0.
> + */
> + if (!(adapter->class & I2C_CLASS_HWMON) && adapter->class)
> + return 0;

NACK on that comment and associated code: Jean Delvare submitted a
patch to NVIDIA over two years ago to fix their bug. Apparently some
distros even carry his patch. So, I don't want to encourage such a
hack to persist. Please just do the standard check here.

> + return i2c_probe(adapter, &addr_data, adt7473_detect);
> +}

(snip)

Thanks & regards,

--
Mark M. Hoffman
mhoffman@xxxxxxxxxxxxx

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