On Tue, Jun 26, 2012 at 11:51:55PM -0500, Robert Lee wrote:
> +static inline int anatop_get_temp(int *temp, struct thermal_zone_device
> *tzdev)
> +{
> + unsigned int n_meas;
> + unsigned int reg;
> + struct imx_anatop_tsdata *sd;
> +
> + sd = &((struct imx_anatop_thdata *)tzdev->devdata)->sensor_data;
> +
> +
> + do {
> + /*
> + * Every time we measure the temperature, we will power on the
> + * temperature sensor, enable measurements, take a reading,
> + * disable measurements, power off the temperature sensor.
> + */
> + sd->handle_suspend = false;
> +
> + anatop_write_reg(sd->anatopmfd, HW_ANADIG_TEMPSENSE0, 0,
> + BM_ANADIG_TEMPSENSE0_POWER_DOWN);
> + anatop_write_reg(sd->anatopmfd, HW_ANADIG_TEMPSENSE0,
> + BM_ANADIG_TEMPSENSE0_MEASURE_TEMP,
> + BM_ANADIG_TEMPSENSE0_MEASURE_TEMP);
> + /*
> + * According to the anatop temp sensor designers, it may require
> + * up to ~17us to complete a measurement (imx6q).
> + * But this timing isn't checked on every part nor is it
> + * specified in the datasheet, so sleeping at least 1ms should
> + * provide plenty of time. Sleeping longer than 1ms is ok so no
> + * need for usleep_range */
> + msleep(1);
> +
> + reg = anatop_read_reg(sd->anatopmfd, HW_ANADIG_TEMPSENSE0);
> +
> + anatop_write_reg(sd->anatopmfd, HW_ANADIG_TEMPSENSE0, 0,
> + BM_ANADIG_TEMPSENSE0_MEASURE_TEMP);
> + anatop_write_reg(sd->anatopmfd, HW_ANADIG_TEMPSENSE0,
> + BM_ANADIG_TEMPSENSE0_POWER_DOWN,
> + BM_ANADIG_TEMPSENSE0_POWER_DOWN);
> +
> + /* if we had a suspend and resume event, we will re-take the reading */
> + } while (sd->handle_suspend);
[...]
> +static int anatop_thermal_suspend(struct platform_device *pdev,
> + pm_message_t state)
> +{
> + struct imx_anatop_thdata *dd = platform_get_drvdata(pdev);
> + struct imx_anatop_tsdata *sd = &dd->sensor_data;
> +
> + /* power off the sensor during suspend */
> + anatop_write_reg(sd->anatopmfd, HW_ANADIG_TEMPSENSE0, 0,
> + BM_ANADIG_TEMPSENSE0_MEASURE_TEMP);
> +
> + anatop_write_reg(sd->anatopmfd, HW_ANADIG_TEMPSENSE0,
> + BM_ANADIG_TEMPSENSE0_POWER_DOWN,
> + BM_ANADIG_TEMPSENSE0_POWER_DOWN);
> + return 0;
> +}
> +
> +static int anatop_thermal_resume(struct platform_device *pdev)
> +{
> + struct imx_anatop_thdata *dd = platform_get_drvdata(pdev);
> + struct imx_anatop_tsdata *sd = &dd->sensor_data;
> +
> + sd->handle_suspend = true;
> + return 0;
> +}
I don't know how to handle this properly or if it's really needed, but
the usage of this handle_suspend variable really looks suspicious. I've
never seen a driver looping around a while-suspended-in-between. Someone
else should have a look over this.
Sascha
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