[PATCHv2 1/5] drm/exynos: add device tree support for rotator

[Chanho Park]

Hi Tomasz,

> -----Original Message-----
> From: Tomasz Figa [mailto:t.figa at samsung.com]
> Sent: Friday, August 09, 2013 9:51 PM
> To: Chanho Park
> Cc: inki.dae at samsung.com; kgene.kim at samsung.com; dri-
> devel at lists.freedesktop.org; kyungmin.park at samsung.com;
> mark.rutland at arm.com; l.stach at pengutronix.de; s.nawrocki at samsung.com;
> tomasz.figa at gmail.com; linux-samsung-soc at vger.kernel.org; linux-arm-
> kernel at lists.infradead.org; devicetree at vger.kernel.org
> Subject: Re: [PATCHv2 1/5] drm/exynos: add device tree support for
> rotator
> 
> Hi Chanho,
> 
> On Friday 09 of August 2013 16:40:49 Chanho Park wrote:
> > The exynos4 platform is only dt-based since 3.10, we should convert
> > driver data and ids to dt-based parsing methods. The rotator driver
> > has a limit table to get size limit of input picture. Each SoCs has
> > slightly different limit value compared with any others.
> > For example, exynos4210's max_size of RGB888 is 16k x 16k. But, others
> > have 8k x 8k. Another example the exynos5250 should have multiple of 2
> > pixel size for its X/Y axis. Thus, we should keep different tables for
> > each of them.
> >
> > Signed-off-by: Chanho Park <chanho61.park at samsung.com>
> > Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
> > ---
> >  drivers/gpu/drm/exynos/exynos_drm_rotator.c |  109
> > ++++++++++++++++++++------- 1 file changed, 81 insertions(+), 28
> > deletions(-)
> >
> > diff --git a/drivers/gpu/drm/exynos/exynos_drm_rotator.c
> > b/drivers/gpu/drm/exynos/exynos_drm_rotator.c index 427640a..39b09e0
> > 100644
> > --- a/drivers/gpu/drm/exynos/exynos_drm_rotator.c
> > +++ b/drivers/gpu/drm/exynos/exynos_drm_rotator.c
> > @@ -632,6 +632,73 @@ static int rotator_ippdrv_start(struct device
> > *dev, enum drm_exynos_ipp_cmd cmd) return 0;  }
> >
> > +static struct rot_limit_table rot_limit_tbl_4210 = {
> > +	.ycbcr420_2p = {
> > +		.min_w = 32,
> > +		.min_h = 32,
> > +		.max_w = SZ_64K,
> > +		.max_h = SZ_64K,
> > +		.align = 3,
> > +	},
> > +	.rgb888 = {
> > +		.min_w = 8,
> > +		.min_h = 8,
> > +		.max_w = SZ_16K,
> > +		.max_h = SZ_16K,
> > +		.align = 2,
> > +	},
> > +};
> > +
> > +static struct rot_limit_table rot_limit_tbl_4x12 = {
> > +	.ycbcr420_2p = {
> > +		.min_w = 32,
> > +		.min_h = 32,
> > +		.max_w = SZ_32K,
> > +		.max_h = SZ_32K,
> > +		.align = 3,
> > +	},
> > +	.rgb888 = {
> > +		.min_w = 8,
> > +		.min_h = 8,
> > +		.max_w = SZ_8K,
> > +		.max_h = SZ_8K,
> > +		.align = 2,
> > +	},
> > +};
> > +
> > +static struct rot_limit_table rot_limit_tbl_5250 = {
> > +	.ycbcr420_2p = {
> > +		.min_w = 32,
> > +		.min_h = 32,
> > +		.max_w = SZ_32K,
> > +		.max_h = SZ_32K,
> > +		.align = 3,
> > +	},
> > +	.rgb888 = {
> > +		.min_w = 8,
> > +		.min_h = 8,
> > +		.max_w = SZ_8K,
> > +		.max_h = SZ_8K,
> > +		.align = 1,
> > +	},
> > +};
> > +
> > +static const struct of_device_id exynos_rotator_match[] = {
> > +	{
> > +		.compatible = "samsung,exynos4210-rotator",
> > +		.data = &rot_limit_tbl_4210,
> > +	},
> > +	{
> > +		.compatible = "samsung,exynos4212-rotator",
> > +		.data = &rot_limit_tbl_4x12,
> > +	},
> > +	{
> > +		.compatible = "samsung,exynos5250-rotator",
> > +		.data = &rot_limit_tbl_5250,
> > +	},
> > +	{},
> > +};
> > +
> >  static int rotator_probe(struct platform_device *pdev)  {
> >  	struct device *dev = &pdev->dev;
> > @@ -645,8 +712,19 @@ static int rotator_probe(struct platform_device
> > *pdev) return -ENOMEM;
> >  	}
> >
> > -	rot->limit_tbl = (struct rot_limit_table *)
> > -				platform_get_device_id(pdev)->driver_data;
> > +	if (dev->of_node) {
> > +		const struct of_device_id *match;
> > +		match = of_match_node(of_match_ptr(exynos_rotator_match),
> > +					dev->of_node);
> > +		if (match == NULL) {
> > +			dev_err(dev, "failed to match node\n");
> > +			return -ENODEV;
> > +		}
> > +		rot->limit_tbl = (struct rot_limit_table *)match->data;
> > +	} else {
> > +		dev_err(dev, "cannot find binding\n");
> 
> What about having a check for !dev->of_node at the beginning of probe,
> to not complicate further code?

I agree with your comment. I'll move it at the beginning.

> 
> Also the error message is confusing. It should be something closer to
> "device does not have of_node".

I'll change it to avoid confusing. Thanks.

> 
> > +		return -ENODEV;
> > +	}
> >
> >  	rot->regs_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >  	rot->regs = devm_ioremap_resource(dev, rot->regs_res); @@ -718,31
> > +796,6 @@ static int rotator_remove(struct platform_device
> > *pdev) return 0;
> >  }
> >
> > -static struct rot_limit_table rot_limit_tbl = {
> > -	.ycbcr420_2p = {
> > -		.min_w = 32,
> > -		.min_h = 32,
> > -		.max_w = SZ_32K,
> > -		.max_h = SZ_32K,
> > -		.align = 3,
> > -	},
> > -	.rgb888 = {
> > -		.min_w = 8,
> > -		.min_h = 8,
> > -		.max_w = SZ_8K,
> > -		.max_h = SZ_8K,
> > -		.align = 2,
> > -	},
> > -};
> > -
> > -static struct platform_device_id rotator_driver_ids[] = {
> > -	{
> > -		.name		= "exynos-rot",
> > -		.driver_data	= (unsigned long)&rot_limit_tbl,
> > -	},
> > -	{},
> > -};
> > -
> >  static int rotator_clk_crtl(struct rot_context *rot, bool enable)  {
> >  	if (enable) {
> > @@ -804,10 +857,10 @@ static const struct dev_pm_ops rotator_pm_ops =
> > {  struct platform_driver rotator_driver = {
> >  	.probe		= rotator_probe,
> >  	.remove		= rotator_remove,
> > -	.id_table	= rotator_driver_ids,
> >  	.driver		= {
> >  		.name	= "exynos-rot",
> >  		.owner	= THIS_MODULE,
> >  		.pm	= &rotator_pm_ops,
> > +		.of_match_table = of_match_ptr(exynos_rotator_match),
> >  	},
> >  };
> 
> Otherwise looks fine.
> 
> One more thing is that IMHO patch 5/5 could be squashed with this one,
> so documentation for the binding would be available at the same it is
> introduced.

Yes. it seems to be better consolidating patch1 and 5.
I'll apply it to next patch.
Thanks.

> 
> Best regards,
> Tomasz