Subject: [PATCH 1/8] [media] s5p-fimc: Use clk_prepare_enable and clk_disable_unprepare

From: [email-masked] (Sylwester Nawrocki)
Date: Wed, 17 Oct 2012 16:33:35 +0200

Hi Sachin,

On 10/17/2012 01:11 PM, Sachin Kamat wrote:
> Replace clk_enable/clk_disable with clk_prepare_enable/clk_disable_unprepare
> as required by the common clock framework.

I think this statement is misleading. In my understanding it is not the 
common clock framework requirement to use clk_{enable/disable}_prepare 
in place of clk_enable/disable. The requirement is to call clk_prepare 
before first clk_enable call and to call clk_unprepare after clk_disable
and before clk_put. 

You need to be careful with those replacements, since the clk *_(un)prepare
functions may sleep, i.e. they must not be called from atomic context.

Most of the s5p-* drivers have already added support for clk_(un)prepare.
Thus most of your changes in this patch are not needed. I seem to have only 
missed fimc-mdevice.c, other modules are already reworked

$ git grep -5  clk_prepare  -- drivers/media/platform/s5p-fimc
drivers/media/platform/s5p-fimc/fimc-core.c-
drivers/media/platform/s5p-fimc/fimc-core.c-    for (i = 0; i < MAX_FIMC_CLOCKS; i++) {
drivers/media/platform/s5p-fimc/fimc-core.c-            fimc->clock[i] = clk_get(&fimc->pdev->dev, fimc_clocks[i]);
drivers/media/platform/s5p-fimc/fimc-core.c-            if (IS_ERR(fimc->clock[i]))
drivers/media/platform/s5p-fimc/fimc-core.c-                    goto err;
drivers/media/platform/s5p-fimc/fimc-core.c:            ret = clk_prepare(fimc->clock[i]);
drivers/media/platform/s5p-fimc/fimc-core.c-            if (ret < 0) {
drivers/media/platform/s5p-fimc/fimc-core.c-                    clk_put(fimc->clock[i]);
drivers/media/platform/s5p-fimc/fimc-core.c-                    fimc->clock[i] = NULL;
drivers/media/platform/s5p-fimc/fimc-core.c-                    goto err;
drivers/media/platform/s5p-fimc/fimc-core.c-            }
--
drivers/media/platform/s5p-fimc/fimc-lite.c-
drivers/media/platform/s5p-fimc/fimc-lite.c-    fimc->clock = clk_get(&fimc->pdev->dev, FLITE_CLK_NAME);
drivers/media/platform/s5p-fimc/fimc-lite.c-    if (IS_ERR(fimc->clock))
drivers/media/platform/s5p-fimc/fimc-lite.c-            return PTR_ERR(fimc->clock);
drivers/media/platform/s5p-fimc/fimc-lite.c-
drivers/media/platform/s5p-fimc/fimc-lite.c:    ret = clk_prepare(fimc->clock);
drivers/media/platform/s5p-fimc/fimc-lite.c-    if (ret < 0) {
drivers/media/platform/s5p-fimc/fimc-lite.c-            clk_put(fimc->clock);
drivers/media/platform/s5p-fimc/fimc-lite.c-            fimc->clock = NULL;
drivers/media/platform/s5p-fimc/fimc-lite.c-    }
drivers/media/platform/s5p-fimc/fimc-lite.c-    return ret;
--
drivers/media/platform/s5p-fimc/mipi-csis.c-
drivers/media/platform/s5p-fimc/mipi-csis.c-    for (i = 0; i < NUM_CSIS_CLOCKS; i++) {
drivers/media/platform/s5p-fimc/mipi-csis.c-            state->clock[i] = clk_get(dev, csi_clock_name[i]);
drivers/media/platform/s5p-fimc/mipi-csis.c-            if (IS_ERR(state->clock[i]))
drivers/media/platform/s5p-fimc/mipi-csis.c-                    goto err;
drivers/media/platform/s5p-fimc/mipi-csis.c:            ret = clk_prepare(state->clock[i]);
drivers/media/platform/s5p-fimc/mipi-csis.c-            if (ret < 0) {
drivers/media/platform/s5p-fimc/mipi-csis.c-                    clk_put(state->clock[i]);
drivers/media/platform/s5p-fimc/mipi-csis.c-                    state->clock[i] = NULL;
drivers/media/platform/s5p-fimc/mipi-csis.c-                    goto err;
drivers/media/platform/s5p-fimc/mipi-csis.c-            }

I would prefer you have added the required changes at fimc_md_get_clocks() 
and fimc_md_put_clocks() functions.

Please make sure you don't add those clk_(un)prepare calls where it is
net needed.

$ git grep "clk_prepare\|clk_unprepare"  -- drivers/media/platform/s5p-*
drivers/media/platform/s5p-fimc/fimc-core.c:            clk_unprepare(fimc->clock[i]);
drivers/media/platform/s5p-fimc/fimc-core.c:            ret = clk_prepare(fimc->clock[i]);
drivers/media/platform/s5p-fimc/fimc-lite.c:    clk_unprepare(fimc->clock);
drivers/media/platform/s5p-fimc/fimc-lite.c:    ret = clk_prepare(fimc->clock);
drivers/media/platform/s5p-fimc/mipi-csis.c:            clk_unprepare(state->clock[i]);
drivers/media/platform/s5p-fimc/mipi-csis.c:            ret = clk_prepare(state->clock[i]);
drivers/media/platform/s5p-g2d/g2d.c:   ret = clk_prepare(dev->clk);
drivers/media/platform/s5p-g2d/g2d.c:   ret = clk_prepare(dev->gate);
drivers/media/platform/s5p-g2d/g2d.c:   clk_unprepare(dev->gate);
drivers/media/platform/s5p-g2d/g2d.c:   clk_unprepare(dev->clk);
drivers/media/platform/s5p-g2d/g2d.c:   clk_unprepare(dev->gate);
drivers/media/platform/s5p-g2d/g2d.c:   clk_unprepare(dev->clk);
drivers/media/platform/s5p-jpeg/jpeg-core.c:    clk_prepare_enable(jpeg->clk);
drivers/media/platform/s5p-mfc/s5p_mfc_pm.c:    ret = clk_prepare(pm->clock_gate);
drivers/media/platform/s5p-mfc/s5p_mfc_pm.c:    ret = clk_prepare(pm->clock);
drivers/media/platform/s5p-mfc/s5p_mfc_pm.c:    clk_unprepare(pm->clock_gate);
drivers/media/platform/s5p-mfc/s5p_mfc_pm.c:    clk_unprepare(pm->clock_gate);
drivers/media/platform/s5p-mfc/s5p_mfc_pm.c:    clk_unprepare(pm->clock);

> Signed-off-by: Sachin Kamat <[email-masked]>
> ---
>  drivers/media/platform/s5p-fimc/fimc-core.c    |   10 +++++-----
>  drivers/media/platform/s5p-fimc/fimc-lite.c    |    4 ++--
>  drivers/media/platform/s5p-fimc/fimc-mdevice.c |    4 ++--
>  drivers/media/platform/s5p-fimc/mipi-csis.c    |   10 +++++-----
>  4 files changed, 14 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/media/platform/s5p-fimc/fimc-core.c b/drivers/media/platform/s5p-fimc/fimc-core.c
> index 8d0d2b9..92308ba 100644
> --- a/drivers/media/platform/s5p-fimc/fimc-core.c
> +++ b/drivers/media/platform/s5p-fimc/fimc-core.c
> @@ -827,7 +827,7 @@ static int fimc_clk_get(struct fimc_dev *fimc)
>  		fimc->clock[i] = clk_get(&fimc->pdev->dev, fimc_clocks[i]);
>  		if (IS_ERR(fimc->clock[i]))
>  			goto err;
> -		ret = clk_prepare(fimc->clock[i]);
> +		ret = clk_prepare_enable(fimc->clock[i]);
>  		if (ret < 0) {
>  			clk_put(fimc->clock[i]);
>  			fimc->clock[i] = NULL;
> @@ -925,7 +925,7 @@ static int fimc_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  	clk_set_rate(fimc->clock[CLK_BUS], drv_data->lclk_frequency);
> -	clk_enable(fimc->clock[CLK_BUS]);
> +	clk_prepare_enable(fimc->clock[CLK_BUS]);
>  
>  	ret = devm_request_irq(&pdev->dev, res->start, fimc_irq_handler,
>  			       0, dev_name(&pdev->dev), fimc);
> @@ -970,7 +970,7 @@ static int fimc_runtime_resume(struct device *dev)
>  	dbg("fimc%d: state: 0x%lx", fimc->id, fimc->state);
>  
>  	/* Enable clocks and perform basic initalization */
> -	clk_enable(fimc->clock[CLK_GATE]);
> +	clk_prepare_enable(fimc->clock[CLK_GATE]);
>  	fimc_hw_reset(fimc);
>  
>  	/* Resume the capture or mem-to-mem device */
> @@ -990,7 +990,7 @@ static int fimc_runtime_suspend(struct device *dev)
>  	else
>  		ret = fimc_m2m_suspend(fimc);
>  	if (!ret)
> -		clk_disable(fimc->clock[CLK_GATE]);
> +		clk_disable_unprepare(fimc->clock[CLK_GATE]);
>  
>  	dbg("fimc%d: state: 0x%lx", fimc->id, fimc->state);
>  	return ret;
> @@ -1045,7 +1045,7 @@ static int __devexit fimc_remove(struct platform_device *pdev)
>  	fimc_unregister_capture_subdev(fimc);
>  	vb2_dma_contig_cleanup_ctx(fimc->alloc_ctx);
>  
> -	clk_disable(fimc->clock[CLK_BUS]);
> +	clk_disable_unprepare(fimc->clock[CLK_BUS]);
>  	fimc_clk_put(fimc);
>  
>  	dev_info(&pdev->dev, "driver unloaded\n");
> diff --git a/drivers/media/platform/s5p-fimc/fimc-lite.c b/drivers/media/platform/s5p-fimc/fimc-lite.c
> index 70bcf39..4a12847 100644
> --- a/drivers/media/platform/s5p-fimc/fimc-lite.c
> +++ b/drivers/media/platform/s5p-fimc/fimc-lite.c
> @@ -1479,7 +1479,7 @@ static int fimc_lite_runtime_resume(struct device *dev)
>  {
>  	struct fimc_lite *fimc = dev_get_drvdata(dev);
>  
> -	clk_enable(fimc->clock);
> +	clk_prepare_enable(fimc->clock);
>  	return 0;
>  }
>  
> @@ -1487,7 +1487,7 @@ static int fimc_lite_runtime_suspend(struct device *dev)
>  {
>  	struct fimc_lite *fimc = dev_get_drvdata(dev);
>  
> -	clk_disable(fimc->clock);
> +	clk_disable_unprepare(fimc->clock);
>  	return 0;
>  }
>  
> diff --git a/drivers/media/platform/s5p-fimc/fimc-mdevice.c b/drivers/media/platform/s5p-fimc/fimc-mdevice.c
> index 61fab00..e1f7cbe 100644
> --- a/drivers/media/platform/s5p-fimc/fimc-mdevice.c
> +++ b/drivers/media/platform/s5p-fimc/fimc-mdevice.c
> @@ -779,7 +779,7 @@ static int __fimc_md_set_camclk(struct fimc_md *fmd,
>  		if (camclk->use_count++ == 0) {
>  			clk_set_rate(camclk->clock, pdata->clk_frequency);
>  			camclk->frequency = pdata->clk_frequency;
> -			ret = clk_enable(camclk->clock);
> +			ret = clk_prepare_enable(camclk->clock);
>  			dbg("Enabled camclk %d: f: %lu", pdata->clk_id,
>  			    clk_get_rate(camclk->clock));
>  		}
> @@ -790,7 +790,7 @@ static int __fimc_md_set_camclk(struct fimc_md *fmd,
>  		return 0;
>  
>  	if (--camclk->use_count == 0) {
> -		clk_disable(camclk->clock);
> +		clk_disable_unprepare(camclk->clock);
>  		dbg("Disabled camclk %d", pdata->clk_id);
>  	}
>  	return ret;
> diff --git a/drivers/media/platform/s5p-fimc/mipi-csis.c b/drivers/media/platform/s5p-fimc/mipi-csis.c
> index 4c961b1..f02c95b 100644
> --- a/drivers/media/platform/s5p-fimc/mipi-csis.c
> +++ b/drivers/media/platform/s5p-fimc/mipi-csis.c
> @@ -710,7 +710,7 @@ static int __devinit s5pcsis_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto e_clkput;
>  
> -	clk_enable(state->clock[CSIS_CLK_MUX]);
> +	clk_prepare_enable(state->clock[CSIS_CLK_MUX]);
>  	if (pdata->clk_rate)
>  		clk_set_rate(state->clock[CSIS_CLK_MUX], pdata->clk_rate);
>  	else
> @@ -754,7 +754,7 @@ static int __devinit s5pcsis_probe(struct platform_device *pdev)
>  e_regput:
>  	regulator_bulk_free(CSIS_NUM_SUPPLIES, state->supplies);
>  e_clkput:
> -	clk_disable(state->clock[CSIS_CLK_MUX]);
> +	clk_disable_unprepare(state->clock[CSIS_CLK_MUX]);
>  	s5pcsis_clk_put(state);
>  	return ret;
>  }
> @@ -779,7 +779,7 @@ static int s5pcsis_pm_suspend(struct device *dev, bool runtime)
>  					     state->supplies);
>  		if (ret)
>  			goto unlock;
> -		clk_disable(state->clock[CSIS_CLK_GATE]);
> +		clk_disable_unprepare(state->clock[CSIS_CLK_GATE]);
>  		state->flags &= ~ST_POWERED;
>  		if (!runtime)
>  			state->flags |= ST_SUSPENDED;
> @@ -816,7 +816,7 @@ static int s5pcsis_pm_resume(struct device *dev, bool runtime)
>  					       state->supplies);
>  			goto unlock;
>  		}
> -		clk_enable(state->clock[CSIS_CLK_GATE]);
> +		clk_prepare_enable(state->clock[CSIS_CLK_GATE]);
>  	}
>  	if (state->flags & ST_STREAMING)
>  		s5pcsis_start_stream(state);
> @@ -858,7 +858,7 @@ static int __devexit s5pcsis_remove(struct platform_device *pdev)
>  
>  	pm_runtime_disable(&pdev->dev);
>  	s5pcsis_pm_suspend(&pdev->dev, false);
> -	clk_disable(state->clock[CSIS_CLK_MUX]);
> +	clk_disable_unprepare(state->clock[CSIS_CLK_MUX]);
>  	pm_runtime_set_suspended(&pdev->dev);
>  	s5pcsis_clk_put(state);
>  	regulator_bulk_free(CSIS_NUM_SUPPLIES, state->supplies);
> 

--
Thanks,
Sylwester