Re: [PATCHv4 2/4] thermal: exynos: Add support for many TRIMINFO_CTRL registers

[Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>]

On Monday, August 25, 2014 01:19:04 PM Bartlomiej Zolnierkiewicz wrote:
> On Monday, August 25, 2014 07:37:25 PM Chanwoo Choi wrote:
> > Hi Bartlomiej,
> > 
> > On 08/25/2014 07:15 PM, Bartlomiej Zolnierkiewicz wrote:
> > > 
> > > Hi,
> > > 
> > > On Monday, August 25, 2014 04:30:23 PM Chanwoo Choi wrote:
> > >> This patch support many TRIMINFO_CTRL registers if specific Exynos SoC
> > >> has one more TRIMINFO_CTRL registers. Also this patch uses proper 'RELOAD'
> > >> shift/mask bit operation to set RELOAD feature instead of static value.
> > >>
> > >> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
> > >> Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
> > >> Cc: Zhang Rui <rui.zhang@intel.com>
> > >> Cc: Eduardo Valentin <edubezval@gmail.com>
> > >> Cc: Amit Daniel Kachhap <amit.daniel@samsung.com>
> > >> Reviewed-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
> > >> ---
> > >>  drivers/thermal/samsung/exynos_thermal_common.h |  1 +
> > >>  drivers/thermal/samsung/exynos_tmu.c            | 23 ++++++++++++++++++++---
> > >>  drivers/thermal/samsung/exynos_tmu.h            |  9 +++++++--
> > >>  drivers/thermal/samsung/exynos_tmu_data.c       |  5 ++++-
> > >>  drivers/thermal/samsung/exynos_tmu_data.h       |  3 +++
> > >>  5 files changed, 35 insertions(+), 6 deletions(-)
> > >>
> > >> diff --git a/drivers/thermal/samsung/exynos_thermal_common.h b/drivers/thermal/samsung/exynos_thermal_common.h
> > >> index 3eb2ed9..b211976 100644
> > >> --- a/drivers/thermal/samsung/exynos_thermal_common.h
> > >> +++ b/drivers/thermal/samsung/exynos_thermal_common.h
> > >> @@ -28,6 +28,7 @@
> > >>  #define MAX_TRIP_COUNT	8
> > >>  #define MAX_COOLING_DEVICE 4
> > >>  #define MAX_THRESHOLD_LEVS 5
> > >> +#define MAX_TRIMINFO_CTRL_REG	2
> > >>  
> > >>  #define ACTIVE_INTERVAL 500
> > >>  #define IDLE_INTERVAL 10000
> > >> diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
> > >> index acbff14..7234f38 100644
> > >> --- a/drivers/thermal/samsung/exynos_tmu.c
> > >> +++ b/drivers/thermal/samsung/exynos_tmu.c
> > >> @@ -147,7 +147,7 @@ static int exynos_tmu_initialize(struct platform_device *pdev)
> > >>  	struct exynos_tmu_data *data = platform_get_drvdata(pdev);
> > >>  	struct exynos_tmu_platform_data *pdata = data->pdata;
> > >>  	const struct exynos_tmu_registers *reg = pdata->registers;
> > >> -	unsigned int status, trim_info = 0, con;
> > >> +	unsigned int status, trim_info = 0, con, ctrl;
> > >>  	unsigned int rising_threshold = 0, falling_threshold = 0;
> > >>  	int ret = 0, threshold_code, i, trigger_levs = 0;
> > >>  
> > >> @@ -164,8 +164,25 @@ static int exynos_tmu_initialize(struct platform_device *pdev)
> > >>  		}
> > >>  	}
> > >>  
> > >> -	if (TMU_SUPPORTS(pdata, TRIM_RELOAD))
> > >> -		__raw_writel(1, data->base + reg->triminfo_ctrl);
> > >> +	if (TMU_SUPPORTS(pdata, TRIM_RELOAD)) {
> > >> +		if (reg->triminfo_ctrl_count > MAX_TRIMINFO_CTRL_REG) {
> > > 
> > > Please remove this check and MAX_TRIMINFO_CTRL_REG define.
> > > 
> > > We do not want such runtime checks for development time errors.
> > 
> > OK, I'll remove it.
> > 
> > > 
> > >> +			ret = -EINVAL;
> > >> +			goto out;
> > >> +		}
> > >> +
> > >> +		for (i = 0; i < reg->triminfo_ctrl_count; i++) {
> > >> +			if (pdata->triminfo_reload[i]) {
> > >> +				ctrl = readl(data->base +
> > >> +						reg->triminfo_ctrl[i]);
> > >> +				ctrl &= ~(reg->triminfo_reload_mask <<
> > >> +						reg->triminfo_reload_shift);
> > >> +				ctrl |= pdata->triminfo_reload[i] <<
> > >> +						reg->triminfo_reload_shift;
> > > 
> > > triminfo_reload_shift and triminfo_reload_mask variables have always
> > > the same values when this code is run so there is no need for them.
> > 
> > I don't understand. Do you mean that timinfo_reload_{shift/mask} variable is un-needed?
> 
> Yes.
> 
> > If you possible, I need more detailed comment.
> 
> Currently triminfo_reload_shift is always "0" and triminfo_reload_mask
> is "1" so there is no need to add an abstraction for different SoCs
> (it should be added only when there is a real need for it).
> 
> Please just rewrite this code as:
> 
> 			if (pdata->triminfo_reload[i]) {
> 				ctrl = readl(data->base +
> 						reg->triminfo_ctrl[i]);
> 				ctrl |= pdata->triminfo_reload[i];
> 				__raw_writel(ctrl, data->base +
> 						reg->triminfo_ctrl[i]);
> 			}

or even better lets get rid of the only __raw_writel() call in Exynos
thermal driver while at it:

			if (pdata->triminfo_reload[i]) {
				ctrl = readl(data->base +
						reg->triminfo_ctrl[i]);
				ctrl |= pdata->triminfo_reload[i];
				writel(ctrl, data->base +
						reg->triminfo_ctrl[i]);
			}

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics