Subject: [PATCH] ti-soc-thermal: implement eocz bit to make driver useful on omap3

From: [email-masked] (Eduardo Valentin)
Date: Sat, 3 Jan 2015 08:26:36 -0400

On Sat, Jan 03, 2015 at 12:46:32PM +0100, Pavel Machek wrote:
> For omap3, proper implementation of eocz bit is needed. It was
> actually a TODO in the driver.
> 
> When periodic mode is not enabled, it is neccessary to force reads.
> 
> Signed-off-by: Pavel Machek <[email-masked]>
> 
> diff --git a/drivers/thermal/ti-soc-thermal/ti-bandgap.c b/drivers/thermal/ti-soc-thermal/ti-bandgap.c
> index 634b6ce..ee63d08 100644
> --- a/drivers/thermal/ti-soc-thermal/ti-bandgap.c
> +++ b/drivers/thermal/ti-soc-thermal/ti-bandgap.c
> @@ -43,6 +43,8 @@
>  
>  #include "ti-bandgap.h"
>  
> +static int ti_bandgap_force_single_read(struct ti_bandgap *bgp, int id);
> +
>  /***   Helper functions to access registers and their bitfields   ***/
>  
>  /**
> @@ -852,14 +831,20 @@ int ti_bandgap_read_temperature(struct ti_bandgap *bgp, int id,
>  	if (ret)
>  		return ret;
>  
> +	if (!TI_BANDGAP_HAS(bgp, MODE_CONFIG)) {
> +		ret = ti_bandgap_force_single_read(bgp, id);

not sure MODE_CONFIG is sufficient condition for single read on all OMAP
versions.

> +		if (ret)
> +			return ret;
> +	}
> +
>  	spin_lock(&bgp->lock);
>  	temp = ti_bandgap_read_temp(bgp, id);
>  	spin_unlock(&bgp->lock);
>  
> -	ret |= ti_bandgap_adc_to_mcelsius(bgp, temp, &temp);
> +	ret = ti_bandgap_adc_to_mcelsius(bgp, temp, &temp);

this one should be part of your clean up patch

>  	if (ret)
>  		return -EIO;
>  
>  	*temperature = temp;
>  
>  	return 0;
> @@ -917,7 +903,8 @@ void *ti_bandgap_get_sensor_data(struct ti_bandgap *bgp, int id)
>  static int
>  ti_bandgap_force_single_read(struct ti_bandgap *bgp, int id)
>  {
> -	u32 temp = 0, counter = 1000;
> +	u32 counter = 1000;
> +	struct temp_sensor_registers *tsr;
>  
>  	/* Select single conversion mode */
>  	if (TI_BANDGAP_HAS(bgp, MODE_CONFIG))
> @@ -925,16 +912,27 @@ ti_bandgap_force_single_read(struct ti_bandgap *bgp, int id)
>  
>  	/* Start of Conversion = 1 */
>  	RMW_BITS(bgp, id, temp_sensor_ctrl, bgap_soc_mask, 1);
> -	/* Wait until DTEMP is updated */
> -	temp = ti_bandgap_read_temp(bgp, id);
>  
> -	while ((temp == 0) && --counter)
> -		temp = ti_bandgap_read_temp(bgp, id);
> -	/* REVISIT: Check correct condition for end of conversion */
> +	/* Wait for EOCZ going up */
> +	tsr = bgp->conf->sensors[id].registers;
> +
> +	while (--counter) {
> +		if (ti_bandgap_readl(bgp, tsr->temp_sensor_ctrl) &
> +		    tsr->bgap_eocz_mask)
> +			break;
> +	}
>  
>  	/* Start of Conversion = 0 */
>  	RMW_BITS(bgp, id, temp_sensor_ctrl, bgap_soc_mask, 0);
>  
> +	/* Wait for EOCZ going down */
> +	counter = 1000;
> +	while (--counter) {
> +		if (!(ti_bandgap_readl(bgp, tsr->temp_sensor_ctrl) &
> +		      tsr->bgap_eocz_mask))
> +			break;
> +	}
> +
>  	return 0;
>  }
>  
> 
> -- 
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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