diff mbox

[v2,2/3] mmc: davinci_mmc: add DT support

Message ID 1360223825-23929-3-git-send-email-prakash.pm@ti.com (mailing list archive)
State Changes Requested
Headers show

Commit Message

Manjunathappa, Prakash Feb. 7, 2013, 7:57 a.m. UTC
Adds device tree support for davinci_mmc. Also add binding documentation.
Tested in non-dma PIO mode and without GPIO card_detect/write_protect
option because of dependencies on EDMA and GPIO module DT support.

Signed-off-by: Manjunathappa, Prakash <prakash.pm@ti.com>
Cc: linux-mmc@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: davinci-linux-open-source@linux.davincidsp.com
Cc: devicetree-discuss@lists.ozlabs.org
Cc: cjb@laptop.org
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: mporter@ti.com
---
Since v1:
Modified DT parse function to take default values and accomodate controller
version in compatible field.

 .../devicetree/bindings/mmc/davinci_mmc.txt        |   30 ++++++++
 drivers/mmc/host/davinci_mmc.c                     |   70 +++++++++++++++++++-
 2 files changed, 99 insertions(+), 1 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mmc/davinci_mmc.txt

Comments

Mark Rutland Feb. 7, 2013, 10:46 a.m. UTC | #1
Hello,

I have a couple of comments on the dt bindings and the way it's parsed.

On Thu, Feb 07, 2013 at 07:57:04AM +0000, Manjunathappa, Prakash wrote:
> Adds device tree support for davinci_mmc. Also add binding documentation.
> Tested in non-dma PIO mode and without GPIO card_detect/write_protect
> option because of dependencies on EDMA and GPIO module DT support.
> 
> Signed-off-by: Manjunathappa, Prakash <prakash.pm@ti.com>
> Cc: linux-mmc@vger.kernel.org
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> Cc: davinci-linux-open-source@linux.davincidsp.com
> Cc: devicetree-discuss@lists.ozlabs.org
> Cc: cjb@laptop.org
> Cc: Sekhar Nori <nsekhar@ti.com>
> Cc: mporter@ti.com
> ---
> Since v1:
> Modified DT parse function to take default values and accomodate controller
> version in compatible field.
> 
>  .../devicetree/bindings/mmc/davinci_mmc.txt        |   30 ++++++++
>  drivers/mmc/host/davinci_mmc.c                     |   70 +++++++++++++++++++-
>  2 files changed, 99 insertions(+), 1 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> 
> diff --git a/Documentation/devicetree/bindings/mmc/davinci_mmc.txt b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> new file mode 100644
> index 0000000..6717ab1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> @@ -0,0 +1,30 @@
> +* TI Highspeed MMC host controller for DaVinci
> +
> +The Highspeed MMC Host Controller on TI DaVinci family
> +provides an interface for MMC, SD and SDIO types of memory cards.
> +
> +This file documents the properties used by the davinci_mmc driver.
> +
> +Required properties:
> +- compatible:
> + Should be "ti,davinci-mmc-da830": for da830, da850, dm365
> + Should be "ti,davinci-mmc-dm355": for dm355, dm644x
> +
> +Optional properties:
> +- bus-width: Number of data lines, can be <4>, or <8>, default <1>
> +- max-frequency: Maximum operating clock frequency, default 25MHz.
> +- mmc-cap-mmc-highspeed: Indicates support for MMC in high speed mode
> +- mmc-cap-sd-highspeed: Indicates support for SD in high speed mode

I thought the last two were derivable from max-frequency?

https://lkml.org/lkml/2012/10/15/231

[...]

> +static struct davinci_mmc_config
> +	*mmc_parse_pdata(struct platform_device *pdev)
>  {
> +	struct device_node *np;
>  	struct davinci_mmc_config *pdata = pdev->dev.platform_data;
> +	const struct of_device_id *match =
> +		of_match_device(of_match_ptr(davinci_mmc_dt_ids), &pdev->dev);
> +	u32 data;
> +
> +	np = pdev->dev.of_node;
> +	if (!np)
> +		return pdata;
> +
> +	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
> +	if (!pdata) {
> +		dev_err(&pdev->dev, "Failed to allocate memory for struct davinci_mmc_config\n");
> +		goto nodata;
> +	}
> +
> +	if (match->data)
> +		pdata->version = (u8)((int)match->data);
> +
> +	of_property_read_u32(np, "max-frequency", &pdata->max_freq);
> +	if (!pdata->max_freq)
> +		dev_info(&pdev->dev, "'max-frequency' property not specified, defaulting to 25MHz\n");
> +
> +	if (of_get_property(np, "mmc-cap-mmc-highspeed", NULL))
> +		pdata->caps |= MMC_CAP_MMC_HIGHSPEED;
> +	if (of_get_property(np, "mmc-cap-sd-highspeed", NULL))
> +		pdata->caps |= MMC_CAP_SD_HIGHSPEED;

If these aren't derivable from max-frequency, you could use
of_property_read_bool to make this clearer.

> +
> +	of_property_read_u32(np, "bus-width", &data);
> +	switch (data) {
> +	case 0:

Judging by the binding doc, should this be 1 rather than 0?

> +	case 4:
> +	case 8:
> +		pdata->wires = data;
> +		break;
> +	default:
> +		pdata->wires = 1;
> +		dev_info(&pdev->dev, "Unsupported buswidth, defaulting to 1 bit\n");
> +	}
> +nodata:
> +	return pdata;
> +}
> +
> +static int __init davinci_mmcsd_probe(struct platform_device *pdev)
> +{
> +	struct davinci_mmc_config *pdata = NULL;
>  	struct mmc_davinci_host *host = NULL;
>  	struct mmc_host *mmc = NULL;
>  	struct resource *r, *mem = NULL;
>  	int ret = 0, irq = 0;
>  	size_t mem_size;
>  
> +	pdata = mmc_parse_pdata(pdev);
> +	if (pdata == NULL) {
> +		dev_err(&pdev->dev, "Can not get platform data\n");
> +		return -ENOENT;
> +	}
> +
>  	/* REVISIT:  when we're fully converted, fail if pdata is NULL */

This comment can presumably disappear judging by the lines above?

[...]

Thanks,
Mark.
Manjunathappa, Prakash Feb. 8, 2013, 6:25 a.m. UTC | #2
Hi Mark,

On Thu, Feb 07, 2013 at 16:16:56, Mark Rutland wrote:
> Hello,
> 
> I have a couple of comments on the dt bindings and the way it's parsed.
> 

Thanks for your review comments.

> On Thu, Feb 07, 2013 at 07:57:04AM +0000, Manjunathappa, Prakash wrote:
> > Adds device tree support for davinci_mmc. Also add binding documentation.
> > Tested in non-dma PIO mode and without GPIO card_detect/write_protect
> > option because of dependencies on EDMA and GPIO module DT support.
> > 
> > Signed-off-by: Manjunathappa, Prakash <prakash.pm@ti.com>
> > Cc: linux-mmc@vger.kernel.org
> > Cc: linux-arm-kernel@lists.infradead.org
> > Cc: linux-kernel@vger.kernel.org
> > Cc: davinci-linux-open-source@linux.davincidsp.com
> > Cc: devicetree-discuss@lists.ozlabs.org
> > Cc: cjb@laptop.org
> > Cc: Sekhar Nori <nsekhar@ti.com>
> > Cc: mporter@ti.com
> > ---
> > Since v1:
> > Modified DT parse function to take default values and accomodate controller
> > version in compatible field.
> > 
> >  .../devicetree/bindings/mmc/davinci_mmc.txt        |   30 ++++++++
> >  drivers/mmc/host/davinci_mmc.c                     |   70 +++++++++++++++++++-
> >  2 files changed, 99 insertions(+), 1 deletions(-)
> >  create mode 100644 Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/mmc/davinci_mmc.txt b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> > new file mode 100644
> > index 0000000..6717ab1
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> > @@ -0,0 +1,30 @@
> > +* TI Highspeed MMC host controller for DaVinci
> > +
> > +The Highspeed MMC Host Controller on TI DaVinci family
> > +provides an interface for MMC, SD and SDIO types of memory cards.
> > +
> > +This file documents the properties used by the davinci_mmc driver.
> > +
> > +Required properties:
> > +- compatible:
> > + Should be "ti,davinci-mmc-da830": for da830, da850, dm365
> > + Should be "ti,davinci-mmc-dm355": for dm355, dm644x
> > +
> > +Optional properties:
> > +- bus-width: Number of data lines, can be <4>, or <8>, default <1>
> > +- max-frequency: Maximum operating clock frequency, default 25MHz.
> > +- mmc-cap-mmc-highspeed: Indicates support for MMC in high speed mode
> > +- mmc-cap-sd-highspeed: Indicates support for SD in high speed mode
> 
> I thought the last two were derivable from max-frequency?
> 

Yes, but I see below comment that it doesnot support MMC/SD.
arch/arm/mach-davinci/devices.c: davinci_setup_mmc
	   "
         * FIXME dm6441 (no MMC/SD), dm357 (one), and dm335 (two) are
         * not handled right here ...
         */"
I was wondering how do we support such platforms, so I thought it is necessary
to have these. But I see that on da850-evm even on skipping above flags EVM is able
to detect card, does it mean there is no way to specify "no SD/MMC" capability?
I will remove these and decide highspeed capability based on max-frequency.

> https://lkml.org/lkml/2012/10/15/231
> 
> [...]
> 
> > +static struct davinci_mmc_config
> > +	*mmc_parse_pdata(struct platform_device *pdev)
> >  {
> > +	struct device_node *np;
> >  	struct davinci_mmc_config *pdata = pdev->dev.platform_data;
> > +	const struct of_device_id *match =
> > +		of_match_device(of_match_ptr(davinci_mmc_dt_ids), &pdev->dev);
> > +	u32 data;
> > +
> > +	np = pdev->dev.of_node;
> > +	if (!np)
> > +		return pdata;
> > +
> > +	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
> > +	if (!pdata) {
> > +		dev_err(&pdev->dev, "Failed to allocate memory for struct davinci_mmc_config\n");
> > +		goto nodata;
> > +	}
> > +
> > +	if (match->data)
> > +		pdata->version = (u8)((int)match->data);
> > +
> > +	of_property_read_u32(np, "max-frequency", &pdata->max_freq);
> > +	if (!pdata->max_freq)
> > +		dev_info(&pdev->dev, "'max-frequency' property not specified, defaulting to 25MHz\n");
> > +
> > +	if (of_get_property(np, "mmc-cap-mmc-highspeed", NULL))
> > +		pdata->caps |= MMC_CAP_MMC_HIGHSPEED;
> > +	if (of_get_property(np, "mmc-cap-sd-highspeed", NULL))
> > +		pdata->caps |= MMC_CAP_SD_HIGHSPEED;
> 
> If these aren't derivable from max-frequency, you could use
> of_property_read_bool to make this clearer.
> 

Correct, I will decide these based on max-frequency.

> > +
> > +	of_property_read_u32(np, "bus-width", &data);
> > +	switch (data) {
> > +	case 0:
> 
> Judging by the binding doc, should this be 1 rather than 0?
> 

By default driver comes up in 4 bit mode when bus-width is not specified.
Bus-width is set to 1 bit for invalid bus-widths. Below are the cases
when bus-width 0 or 4, bus-width is set to 4bit mode
When bus-width is 8, bus-width is set to 8 bit mode

I thought that if somebody specifies bus-width as 2, 3, 5, 6, 7..., then
it should be defaulted to 1 bit mode, so I specified it as 1 bit in binding doc.
But I feel that a person who is editing dts file will not make such a mistake.
I will change binding document to default as 4 bit mode.

> > +	case 4:
> > +	case 8:
> > +		pdata->wires = data;
> > +		break;
> > +	default:
> > +		pdata->wires = 1;
> > +		dev_info(&pdev->dev, "Unsupported buswidth, defaulting to 1 bit\n");
> > +	}
> > +nodata:
> > +	return pdata;
> > +}
> > +
> > +static int __init davinci_mmcsd_probe(struct platform_device *pdev)
> > +{
> > +	struct davinci_mmc_config *pdata = NULL;
> >  	struct mmc_davinci_host *host = NULL;
> >  	struct mmc_host *mmc = NULL;
> >  	struct resource *r, *mem = NULL;
> >  	int ret = 0, irq = 0;
> >  	size_t mem_size;
> >  
> > +	pdata = mmc_parse_pdata(pdev);
> > +	if (pdata == NULL) {
> > +		dev_err(&pdev->dev, "Can not get platform data\n");
> > +		return -ENOENT;
> > +	}
> > +
> >  	/* REVISIT:  when we're fully converted, fail if pdata is NULL */
> 
> This comment can presumably disappear judging by the lines above?
> 

Agreed. I will remove it.

Thanks,
Prakash
Mark Rutland Feb. 8, 2013, 9:37 a.m. UTC | #3
Hi,

[...]

> > > diff --git a/Documentation/devicetree/bindings/mmc/davinci_mmc.txt b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> > > new file mode 100644
> > > index 0000000..6717ab1
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> > > @@ -0,0 +1,30 @@
> > > +* TI Highspeed MMC host controller for DaVinci
> > > +
> > > +The Highspeed MMC Host Controller on TI DaVinci family
> > > +provides an interface for MMC, SD and SDIO types of memory cards.
> > > +
> > > +This file documents the properties used by the davinci_mmc driver.
> > > +
> > > +Required properties:
> > > +- compatible:
> > > + Should be "ti,davinci-mmc-da830": for da830, da850, dm365
> > > + Should be "ti,davinci-mmc-dm355": for dm355, dm644x
> > > +
> > > +Optional properties:
> > > +- bus-width: Number of data lines, can be <4>, or <8>, default <1>
> > > +- max-frequency: Maximum operating clock frequency, default 25MHz.
> > > +- mmc-cap-mmc-highspeed: Indicates support for MMC in high speed mode
> > > +- mmc-cap-sd-highspeed: Indicates support for SD in high speed mode

[...]


> > > +static struct davinci_mmc_config
> > > +	*mmc_parse_pdata(struct platform_device *pdev)
> > >  {
> > > +	struct device_node *np;
> > >  	struct davinci_mmc_config *pdata = pdev->dev.platform_data;
> > > +	const struct of_device_id *match =
> > > +		of_match_device(of_match_ptr(davinci_mmc_dt_ids), &pdev->dev);
> > > +	u32 data;
> > > +
> > > +	np = pdev->dev.of_node;
> > > +	if (!np)
> > > +		return pdata;
> > > +
> > > +	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
> > > +	if (!pdata) {
> > > +		dev_err(&pdev->dev, "Failed to allocate memory for struct davinci_mmc_config\n");
> > > +		goto nodata;
> > > +	}
> > > +
> > > +	if (match->data)
> > > +		pdata->version = (u8)((int)match->data);
> > > +
> > > +	of_property_read_u32(np, "max-frequency", &pdata->max_freq);
> > > +	if (!pdata->max_freq)
> > > +		dev_info(&pdev->dev, "'max-frequency' property not specified, defaulting to 25MHz\n");
> > > +
> > > +	if (of_get_property(np, "mmc-cap-mmc-highspeed", NULL))
> > > +		pdata->caps |= MMC_CAP_MMC_HIGHSPEED;
> > > +	if (of_get_property(np, "mmc-cap-sd-highspeed", NULL))
> > > +		pdata->caps |= MMC_CAP_SD_HIGHSPEED;
> > 
> > If these aren't derivable from max-frequency, you could use
> > of_property_read_bool to make this clearer.
> > 
> 
> Correct, I will decide these based on max-frequency.
> 
> > > +
> > > +	of_property_read_u32(np, "bus-width", &data);
> > > +	switch (data) {
> > > +	case 0:
> > 
> > Judging by the binding doc, should this be 1 rather than 0?
> > 
> 
> By default driver comes up in 4 bit mode when bus-width is not specified.
> Bus-width is set to 1 bit for invalid bus-widths. Below are the cases
> when bus-width 0 or 4, bus-width is set to 4bit mode
> When bus-width is 8, bus-width is set to 8 bit mode

Why is 0 a special value that means 4? Why not just use 4?

Here you just assign 0 to pdata->wires.

I see the current version of the driver handles this specially in
davinci_mmcsd_probe, but I don't see why this should leak into the binding.

What I was originally trying to get at is that the binding says 8, 4, and 1 are
acceptable values, but you check the cases 8, 4, or 0. So you're accepting
something not documented, and producing a warning in a valid case (1).

> 
> I thought that if somebody specifies bus-width as 2, 3, 5, 6, 7..., then
> it should be defaulted to 1 bit mode, so I specified it as 1 bit in binding doc.

If they specify something invalid, falling back to a sane value with a warning
sounds good.

> But I feel that a person who is editing dts file will not make such a mistake.
> I will change binding document to default as 4 bit mode.

There have been and inevitably will be plenty of errors in dts files. I think
it'd be good to provide a warning and either use a value that's guaranteed to
work, or bail out if that can't be done.

If it's always valid to use 1 data line even if the hardware has more, I think
falling back to 1 makes more sense, as it'd be guaranteed to work.

> 
> > > +	case 4:
> > > +	case 8:
> > > +		pdata->wires = data;
> > > +		break;
> > > +	default:
> > > +		pdata->wires = 1;
> > > +		dev_info(&pdev->dev, "Unsupported buswidth, defaulting to 1 bit\n");
> > > +	}
> > > +nodata:
> > > +	return pdata;
> > > +}

With the first case changed to "case 1:", this block makes sense to me.

Thanks,
Mark.
Manjunathappa, Prakash Feb. 8, 2013, 10:04 a.m. UTC | #4
Hi,

On Fri, Feb 08, 2013 at 15:07:54, Mark Rutland wrote:
> Hi,
> 
> [...]
> 
> > > > diff --git a/Documentation/devicetree/bindings/mmc/davinci_mmc.txt b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> > > > new file mode 100644
> > > > index 0000000..6717ab1
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> > > > @@ -0,0 +1,30 @@
> > > > +* TI Highspeed MMC host controller for DaVinci
> > > > +
> > > > +The Highspeed MMC Host Controller on TI DaVinci family
> > > > +provides an interface for MMC, SD and SDIO types of memory cards.
> > > > +
> > > > +This file documents the properties used by the davinci_mmc driver.
> > > > +
> > > > +Required properties:
> > > > +- compatible:
> > > > + Should be "ti,davinci-mmc-da830": for da830, da850, dm365
> > > > + Should be "ti,davinci-mmc-dm355": for dm355, dm644x
> > > > +
> > > > +Optional properties:
> > > > +- bus-width: Number of data lines, can be <4>, or <8>, default <1>
> > > > +- max-frequency: Maximum operating clock frequency, default 25MHz.
> > > > +- mmc-cap-mmc-highspeed: Indicates support for MMC in high speed mode
> > > > +- mmc-cap-sd-highspeed: Indicates support for SD in high speed mode
> 
> [...]
> 
> 
> > > > +static struct davinci_mmc_config
> > > > +	*mmc_parse_pdata(struct platform_device *pdev)
> > > >  {
> > > > +	struct device_node *np;
> > > >  	struct davinci_mmc_config *pdata = pdev->dev.platform_data;
> > > > +	const struct of_device_id *match =
> > > > +		of_match_device(of_match_ptr(davinci_mmc_dt_ids), &pdev->dev);
> > > > +	u32 data;
> > > > +
> > > > +	np = pdev->dev.of_node;
> > > > +	if (!np)
> > > > +		return pdata;
> > > > +
> > > > +	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
> > > > +	if (!pdata) {
> > > > +		dev_err(&pdev->dev, "Failed to allocate memory for struct davinci_mmc_config\n");
> > > > +		goto nodata;
> > > > +	}
> > > > +
> > > > +	if (match->data)
> > > > +		pdata->version = (u8)((int)match->data);
> > > > +
> > > > +	of_property_read_u32(np, "max-frequency", &pdata->max_freq);
> > > > +	if (!pdata->max_freq)
> > > > +		dev_info(&pdev->dev, "'max-frequency' property not specified, defaulting to 25MHz\n");
> > > > +
> > > > +	if (of_get_property(np, "mmc-cap-mmc-highspeed", NULL))
> > > > +		pdata->caps |= MMC_CAP_MMC_HIGHSPEED;
> > > > +	if (of_get_property(np, "mmc-cap-sd-highspeed", NULL))
> > > > +		pdata->caps |= MMC_CAP_SD_HIGHSPEED;
> > > 
> > > If these aren't derivable from max-frequency, you could use
> > > of_property_read_bool to make this clearer.
> > > 
> > 
> > Correct, I will decide these based on max-frequency.
> > 
> > > > +
> > > > +	of_property_read_u32(np, "bus-width", &data);
> > > > +	switch (data) {
> > > > +	case 0:
> > > 
> > > Judging by the binding doc, should this be 1 rather than 0?
> > > 
> > 
> > By default driver comes up in 4 bit mode when bus-width is not specified.
> > Bus-width is set to 1 bit for invalid bus-widths. Below are the cases
> > when bus-width 0 or 4, bus-width is set to 4bit mode
> > When bus-width is 8, bus-width is set to 8 bit mode
> 
> Why is 0 a special value that means 4? Why not just use 4?
> 
> Here you just assign 0 to pdata->wires.
> 
> I see the current version of the driver handles this specially in
> davinci_mmcsd_probe, but I don't see why this should leak into the binding.
> 

Yes, I was trying to push in current driver behavior into binding documentation.

> What I was originally trying to get at is that the binding says 8, 4, and 1 are
> acceptable values, but you check the cases 8, 4, or 0. So you're accepting
> something not documented, and producing a warning in a valid case (1).
> 

Valid point.

> > 
> > I thought that if somebody specifies bus-width as 2, 3, 5, 6, 7..., then
> > it should be defaulted to 1 bit mode, so I specified it as 1 bit in binding doc.
> 
> If they specify something invalid, falling back to a sane value with a warning
> sounds good.
> 

True.

> > But I feel that a person who is editing dts file will not make such a mistake.
> > I will change binding document to default as 4 bit mode.
> 
> There have been and inevitably will be plenty of errors in dts files. I think
> it'd be good to provide a warning and either use a value that's guaranteed to
> work, or bail out if that can't be done.
> 
> If it's always valid to use 1 data line even if the hardware has more, I think
> falling back to 1 makes more sense, as it'd be guaranteed to work.
> 

I completely agree with you, thanks for your inputs.
Will add valid case 1:

Thanks,
Prakash

> > 
> > > > +	case 4:
> > > > +	case 8:
> > > > +		pdata->wires = data;
> > > > +		break;
> > > > +	default:
> > > > +		pdata->wires = 1;
> > > > +		dev_info(&pdev->dev, "Unsupported buswidth, defaulting to 1 bit\n");
> > > > +	}
> > > > +nodata:
> > > > +	return pdata;
> > > > +}
> 
> With the first case changed to "case 1:", this block makes sense to me.
> 
> Thanks,
> Mark.
> 
>
Manjunathappa, Prakash Feb. 11, 2013, 5:31 a.m. UTC | #5
Hi Mark,

On Fri, Feb 08, 2013 at 11:55:09, Manjunathappa, Prakash wrote:
> Hi Mark,
> 
> On Thu, Feb 07, 2013 at 16:16:56, Mark Rutland wrote:
> > Hello,
> > 
> > I have a couple of comments on the dt bindings and the way it's parsed.
> > 
> 
> Thanks for your review comments.
> 
> > On Thu, Feb 07, 2013 at 07:57:04AM +0000, Manjunathappa, Prakash wrote:
> > > Adds device tree support for davinci_mmc. Also add binding documentation.
> > > Tested in non-dma PIO mode and without GPIO card_detect/write_protect
> > > option because of dependencies on EDMA and GPIO module DT support.
> > > 
> > > Signed-off-by: Manjunathappa, Prakash <prakash.pm@ti.com>
> > > Cc: linux-mmc@vger.kernel.org
> > > Cc: linux-arm-kernel@lists.infradead.org
> > > Cc: linux-kernel@vger.kernel.org
> > > Cc: davinci-linux-open-source@linux.davincidsp.com
> > > Cc: devicetree-discuss@lists.ozlabs.org
> > > Cc: cjb@laptop.org
> > > Cc: Sekhar Nori <nsekhar@ti.com>
> > > Cc: mporter@ti.com
> > > ---
> > > Since v1:
> > > Modified DT parse function to take default values and accomodate controller
> > > version in compatible field.
> > > 
> > >  .../devicetree/bindings/mmc/davinci_mmc.txt        |   30 ++++++++
> > >  drivers/mmc/host/davinci_mmc.c                     |   70 +++++++++++++++++++-
> > >  2 files changed, 99 insertions(+), 1 deletions(-)
> > >  create mode 100644 Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> > > 
> > > diff --git a/Documentation/devicetree/bindings/mmc/davinci_mmc.txt b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> > > new file mode 100644
> > > index 0000000..6717ab1
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> > > @@ -0,0 +1,30 @@
> > > +* TI Highspeed MMC host controller for DaVinci
> > > +
> > > +The Highspeed MMC Host Controller on TI DaVinci family
> > > +provides an interface for MMC, SD and SDIO types of memory cards.
> > > +
> > > +This file documents the properties used by the davinci_mmc driver.
> > > +
> > > +Required properties:
> > > +- compatible:
> > > + Should be "ti,davinci-mmc-da830": for da830, da850, dm365
> > > + Should be "ti,davinci-mmc-dm355": for dm355, dm644x
> > > +
> > > +Optional properties:
> > > +- bus-width: Number of data lines, can be <4>, or <8>, default <1>
> > > +- max-frequency: Maximum operating clock frequency, default 25MHz.
> > > +- mmc-cap-mmc-highspeed: Indicates support for MMC in high speed mode
> > > +- mmc-cap-sd-highspeed: Indicates support for SD in high speed mode
> > 
> > I thought the last two were derivable from max-frequency?
> > 
> 
> Yes, but I see below comment that it doesnot support MMC/SD.
> arch/arm/mach-davinci/devices.c: davinci_setup_mmc
> 	   "
>          * FIXME dm6441 (no MMC/SD), dm357 (one), and dm335 (two) are
>          * not handled right here ...
>          */"
> I was wondering how do we support such platforms, so I thought it is necessary
> to have these. But I see that on da850-evm even on skipping above flags EVM is able
> to detect card, does it mean there is no way to specify "no SD/MMC" capability?
> I will remove these and decide highspeed capability based on max-frequency.
> 

Since this comment also applies for existing non-DT driver, I will plan to take
up activity later. For now I will submit next version of DT support patch
excluding highspeed card capability.

Thanks,
Prakash

[...]
Sekhar Nori Feb. 12, 2013, 6:21 a.m. UTC | #6
On 2/7/2013 1:27 PM, Manjunathappa, Prakash wrote:
> Adds device tree support for davinci_mmc. Also add binding documentation.
> Tested in non-dma PIO mode and without GPIO card_detect/write_protect
> option because of dependencies on EDMA and GPIO module DT support.
> 
> Signed-off-by: Manjunathappa, Prakash <prakash.pm@ti.com>
> Cc: linux-mmc@vger.kernel.org
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> Cc: davinci-linux-open-source@linux.davincidsp.com
> Cc: devicetree-discuss@lists.ozlabs.org
> Cc: cjb@laptop.org
> Cc: Sekhar Nori <nsekhar@ti.com>
> Cc: mporter@ti.com
> ---
> Since v1:
> Modified DT parse function to take default values and accomodate controller
> version in compatible field.
> 
>  .../devicetree/bindings/mmc/davinci_mmc.txt        |   30 ++++++++
>  drivers/mmc/host/davinci_mmc.c                     |   70 +++++++++++++++++++-
>  2 files changed, 99 insertions(+), 1 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> 
> diff --git a/Documentation/devicetree/bindings/mmc/davinci_mmc.txt b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> new file mode 100644
> index 0000000..6717ab1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> @@ -0,0 +1,30 @@
> +* TI Highspeed MMC host controller for DaVinci
> +
> +The Highspeed MMC Host Controller on TI DaVinci family
> +provides an interface for MMC, SD and SDIO types of memory cards.
> +
> +This file documents the properties used by the davinci_mmc driver.
> +
> +Required properties:
> +- compatible:
> + Should be "ti,davinci-mmc-da830": for da830, da850, dm365
> + Should be "ti,davinci-mmc-dm355": for dm355, dm644x
> +
> +Optional properties:
> +- bus-width: Number of data lines, can be <4>, or <8>, default <1>
> +- max-frequency: Maximum operating clock frequency, default 25MHz.
> +- mmc-cap-mmc-highspeed: Indicates support for MMC in high speed mode
> +- mmc-cap-sd-highspeed: Indicates support for SD in high speed mode
> +
> +Example:
> +	mmc0: mmc@1c40000 {
> +		compatible = "ti,davinci-mmc-da830",
> +		reg = <0x40000 0x1000>;
> +		interrupts = <16>;
> +		status = "okay";
> +		bus-width = <4>;
> +		max-frequency = <50000000>;
> +		mmc-cap-sd-highspeed;
> +		mmc-cap-mmc-highspeed;
> +	};
> +
> diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c
> index 27123f8..3f90316 100644
> --- a/drivers/mmc/host/davinci_mmc.c
> +++ b/drivers/mmc/host/davinci_mmc.c
> @@ -34,6 +34,8 @@
>  #include <linux/dma-mapping.h>
>  #include <linux/edma.h>
>  #include <linux/mmc/mmc.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
>  
>  #include <linux/platform_data/mmc-davinci.h>
>  
> @@ -1157,15 +1159,80 @@ static void __init init_mmcsd_host(struct mmc_davinci_host *host)
>  	mmc_davinci_reset_ctrl(host, 0);
>  }
>  
> -static int __init davinci_mmcsd_probe(struct platform_device *pdev)
> +static const struct of_device_id davinci_mmc_dt_ids[] = {
> +	{
> +		.compatible = "ti,davinci-mmc-dm355",
> +		.data = (void *)MMC_CTLR_VERSION_1,
> +	},
> +	{
> +		.compatible = "ti,davinci-mmc-da830",
> +		.data = (void *)MMC_CTLR_VERSION_2,
> +	},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, davinci_mmc_dt_ids);

If you are doing this why not also kill passing IP version through
platform data using a platform_device_id table? Look at what Afzal did
for drivers/rtc/rtc-omap.c

Thanks,
Sekhar
Manjunathappa, Prakash Feb. 14, 2013, 6:19 a.m. UTC | #7
Hi Sekhar,

This mail reached my inbox after I sent out v3.

On Tue, Feb 12, 2013 at 11:51:34, Nori, Sekhar wrote:
> On 2/7/2013 1:27 PM, Manjunathappa, Prakash wrote:
> > Adds device tree support for davinci_mmc. Also add binding documentation.
> > Tested in non-dma PIO mode and without GPIO card_detect/write_protect
> > option because of dependencies on EDMA and GPIO module DT support.
> > 
> > Signed-off-by: Manjunathappa, Prakash <prakash.pm@ti.com>
> > Cc: linux-mmc@vger.kernel.org
> > Cc: linux-arm-kernel@lists.infradead.org
> > Cc: linux-kernel@vger.kernel.org
> > Cc: davinci-linux-open-source@linux.davincidsp.com
> > Cc: devicetree-discuss@lists.ozlabs.org
> > Cc: cjb@laptop.org
> > Cc: Sekhar Nori <nsekhar@ti.com>
> > Cc: mporter@ti.com
> > ---
> > Since v1:
> > Modified DT parse function to take default values and accomodate controller
> > version in compatible field.
> > 
> >  .../devicetree/bindings/mmc/davinci_mmc.txt        |   30 ++++++++
> >  drivers/mmc/host/davinci_mmc.c                     |   70 +++++++++++++++++++-
> >  2 files changed, 99 insertions(+), 1 deletions(-)
> >  create mode 100644 Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/mmc/davinci_mmc.txt b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> > new file mode 100644
> > index 0000000..6717ab1
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
> > @@ -0,0 +1,30 @@
> > +* TI Highspeed MMC host controller for DaVinci
> > +
> > +The Highspeed MMC Host Controller on TI DaVinci family
> > +provides an interface for MMC, SD and SDIO types of memory cards.
> > +
> > +This file documents the properties used by the davinci_mmc driver.
> > +
> > +Required properties:
> > +- compatible:
> > + Should be "ti,davinci-mmc-da830": for da830, da850, dm365
> > + Should be "ti,davinci-mmc-dm355": for dm355, dm644x
> > +
> > +Optional properties:
> > +- bus-width: Number of data lines, can be <4>, or <8>, default <1>
> > +- max-frequency: Maximum operating clock frequency, default 25MHz.
> > +- mmc-cap-mmc-highspeed: Indicates support for MMC in high speed mode
> > +- mmc-cap-sd-highspeed: Indicates support for SD in high speed mode
> > +
> > +Example:
> > +	mmc0: mmc@1c40000 {
> > +		compatible = "ti,davinci-mmc-da830",
> > +		reg = <0x40000 0x1000>;
> > +		interrupts = <16>;
> > +		status = "okay";
> > +		bus-width = <4>;
> > +		max-frequency = <50000000>;
> > +		mmc-cap-sd-highspeed;
> > +		mmc-cap-mmc-highspeed;
> > +	};
> > +
> > diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c
> > index 27123f8..3f90316 100644
> > --- a/drivers/mmc/host/davinci_mmc.c
> > +++ b/drivers/mmc/host/davinci_mmc.c
> > @@ -34,6 +34,8 @@
> >  #include <linux/dma-mapping.h>
> >  #include <linux/edma.h>
> >  #include <linux/mmc/mmc.h>
> > +#include <linux/of.h>
> > +#include <linux/of_device.h>
> >  
> >  #include <linux/platform_data/mmc-davinci.h>
> >  
> > @@ -1157,15 +1159,80 @@ static void __init init_mmcsd_host(struct mmc_davinci_host *host)
> >  	mmc_davinci_reset_ctrl(host, 0);
> >  }
> >  
> > -static int __init davinci_mmcsd_probe(struct platform_device *pdev)
> > +static const struct of_device_id davinci_mmc_dt_ids[] = {
> > +	{
> > +		.compatible = "ti,davinci-mmc-dm355",
> > +		.data = (void *)MMC_CTLR_VERSION_1,
> > +	},
> > +	{
> > +		.compatible = "ti,davinci-mmc-da830",
> > +		.data = (void *)MMC_CTLR_VERSION_2,
> > +	},
> > +	{},
> > +};
> > +MODULE_DEVICE_TABLE(of, davinci_mmc_dt_ids);
> 
> If you are doing this why not also kill passing IP version through
> platform data using a platform_device_id table? Look at what Afzal did
> for drivers/rtc/rtc-omap.c
> 

Agreed, I will send out v4 having these changes also in this series.

Thanks,
Prakash

> Thanks,
> Sekhar
>
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/mmc/davinci_mmc.txt b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
new file mode 100644
index 0000000..6717ab1
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/davinci_mmc.txt
@@ -0,0 +1,30 @@ 
+* TI Highspeed MMC host controller for DaVinci
+
+The Highspeed MMC Host Controller on TI DaVinci family
+provides an interface for MMC, SD and SDIO types of memory cards.
+
+This file documents the properties used by the davinci_mmc driver.
+
+Required properties:
+- compatible:
+ Should be "ti,davinci-mmc-da830": for da830, da850, dm365
+ Should be "ti,davinci-mmc-dm355": for dm355, dm644x
+
+Optional properties:
+- bus-width: Number of data lines, can be <4>, or <8>, default <1>
+- max-frequency: Maximum operating clock frequency, default 25MHz.
+- mmc-cap-mmc-highspeed: Indicates support for MMC in high speed mode
+- mmc-cap-sd-highspeed: Indicates support for SD in high speed mode
+
+Example:
+	mmc0: mmc@1c40000 {
+		compatible = "ti,davinci-mmc-da830",
+		reg = <0x40000 0x1000>;
+		interrupts = <16>;
+		status = "okay";
+		bus-width = <4>;
+		max-frequency = <50000000>;
+		mmc-cap-sd-highspeed;
+		mmc-cap-mmc-highspeed;
+	};
+
diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c
index 27123f8..3f90316 100644
--- a/drivers/mmc/host/davinci_mmc.c
+++ b/drivers/mmc/host/davinci_mmc.c
@@ -34,6 +34,8 @@ 
 #include <linux/dma-mapping.h>
 #include <linux/edma.h>
 #include <linux/mmc/mmc.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 #include <linux/platform_data/mmc-davinci.h>
 
@@ -1157,15 +1159,80 @@  static void __init init_mmcsd_host(struct mmc_davinci_host *host)
 	mmc_davinci_reset_ctrl(host, 0);
 }
 
-static int __init davinci_mmcsd_probe(struct platform_device *pdev)
+static const struct of_device_id davinci_mmc_dt_ids[] = {
+	{
+		.compatible = "ti,davinci-mmc-dm355",
+		.data = (void *)MMC_CTLR_VERSION_1,
+	},
+	{
+		.compatible = "ti,davinci-mmc-da830",
+		.data = (void *)MMC_CTLR_VERSION_2,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, davinci_mmc_dt_ids);
+
+static struct davinci_mmc_config
+	*mmc_parse_pdata(struct platform_device *pdev)
 {
+	struct device_node *np;
 	struct davinci_mmc_config *pdata = pdev->dev.platform_data;
+	const struct of_device_id *match =
+		of_match_device(of_match_ptr(davinci_mmc_dt_ids), &pdev->dev);
+	u32 data;
+
+	np = pdev->dev.of_node;
+	if (!np)
+		return pdata;
+
+	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata) {
+		dev_err(&pdev->dev, "Failed to allocate memory for struct davinci_mmc_config\n");
+		goto nodata;
+	}
+
+	if (match->data)
+		pdata->version = (u8)((int)match->data);
+
+	of_property_read_u32(np, "max-frequency", &pdata->max_freq);
+	if (!pdata->max_freq)
+		dev_info(&pdev->dev, "'max-frequency' property not specified, defaulting to 25MHz\n");
+
+	if (of_get_property(np, "mmc-cap-mmc-highspeed", NULL))
+		pdata->caps |= MMC_CAP_MMC_HIGHSPEED;
+	if (of_get_property(np, "mmc-cap-sd-highspeed", NULL))
+		pdata->caps |= MMC_CAP_SD_HIGHSPEED;
+
+	of_property_read_u32(np, "bus-width", &data);
+	switch (data) {
+	case 0:
+	case 4:
+	case 8:
+		pdata->wires = data;
+		break;
+	default:
+		pdata->wires = 1;
+		dev_info(&pdev->dev, "Unsupported buswidth, defaulting to 1 bit\n");
+	}
+nodata:
+	return pdata;
+}
+
+static int __init davinci_mmcsd_probe(struct platform_device *pdev)
+{
+	struct davinci_mmc_config *pdata = NULL;
 	struct mmc_davinci_host *host = NULL;
 	struct mmc_host *mmc = NULL;
 	struct resource *r, *mem = NULL;
 	int ret = 0, irq = 0;
 	size_t mem_size;
 
+	pdata = mmc_parse_pdata(pdev);
+	if (pdata == NULL) {
+		dev_err(&pdev->dev, "Can not get platform data\n");
+		return -ENOENT;
+	}
+
 	/* REVISIT:  when we're fully converted, fail if pdata is NULL */
 
 	ret = -ENODEV;
@@ -1408,6 +1475,7 @@  static struct platform_driver davinci_mmcsd_driver = {
 		.name	= "davinci_mmc",
 		.owner	= THIS_MODULE,
 		.pm	= davinci_mmcsd_pm_ops,
+		.of_match_table = of_match_ptr(davinci_mmc_dt_ids),
 	},
 	.remove		= __exit_p(davinci_mmcsd_remove),
 };