diff mbox

[v4,6/8] mfd: cros_ec: Support multiple EC in a system

Message ID 1433232671-27679-7-git-send-email-javier.martinez@collabora.co.uk (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Javier Martinez Canillas June 2, 2015, 8:11 a.m. UTC
From: Gwendal Grignou <gwendal@chromium.org>

Chromebooks can have more than one Embedded Controller so the
cros_ec device id has to be incremented for each EC registered.

Add code to handle multiple EC. First ec found is cros-ec0,
second cros-ec1 and so on.

Add a new structure to represent multiple EC as different char
devices (e.g: /dev/cros_ec, /dev/cros_pd). It connects to
cros_ec_device and allows sysfs inferface for cros_pd.

Also reduce number of allocated objects, make chromeos sysfs
class object a static and add refcounting to prevent object
deletion while command is in progress.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
---

Changes since v3:
 - Add defines for the EC and PD index constants.
 - Remove cros_ec_dev_register() and declare the mfd_cells as static structs.
   Suggested by Lee Jones.
 - Add a new line before the return statement in cros_ec_dev_register().
   Suggested by Lee Jones.

Changes since v2: None

Changes since v1:
  - Squash patch that adds support to represent EC's as different
    char devices (e.g: /dev/cros_ec, /dev/cros_pd):
    https://chromium-review.googlesource.com/#/c/217297/
    Suggested by Gwendal Grignou
  - Use cros_ec instead of cros-ec in the subject line to be consistent.
    Suggested by Gwendal Grignou
---
 drivers/input/keyboard/cros_ec_keyb.c      |   2 +-
 drivers/mfd/cros_ec.c                      |  59 +++++++++++--
 drivers/mfd/cros_ec_i2c.c                  |   1 -
 drivers/mfd/cros_ec_spi.c                  |   1 -
 drivers/platform/chrome/cros_ec_dev.c      | 128 ++++++++++++++++++++---------
 drivers/platform/chrome/cros_ec_dev.h      |   7 --
 drivers/platform/chrome/cros_ec_lightbar.c |  75 +++++++++--------
 drivers/platform/chrome/cros_ec_lpc.c      |   1 -
 drivers/platform/chrome/cros_ec_sysfs.c    |  48 +++++------
 include/linux/mfd/cros_ec.h                |  44 ++++++++--
 10 files changed, 240 insertions(+), 126 deletions(-)

Comments

Lee Jones June 3, 2015, 8:53 a.m. UTC | #1
On Tue, 02 Jun 2015, Javier Martinez Canillas wrote:

> From: Gwendal Grignou <gwendal@chromium.org>
> 
> Chromebooks can have more than one Embedded Controller so the
> cros_ec device id has to be incremented for each EC registered.
> 
> Add code to handle multiple EC. First ec found is cros-ec0,
> second cros-ec1 and so on.
> 
> Add a new structure to represent multiple EC as different char
> devices (e.g: /dev/cros_ec, /dev/cros_pd). It connects to
> cros_ec_device and allows sysfs inferface for cros_pd.
> 
> Also reduce number of allocated objects, make chromeos sysfs
> class object a static and add refcounting to prevent object
> deletion while command is in progress.
> 
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> Reviewed-by: Dmitry Torokhov <dtor@chromium.org>
> Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
> ---
> 
> Changes since v3:
>  - Add defines for the EC and PD index constants.
>  - Remove cros_ec_dev_register() and declare the mfd_cells as static structs.
>    Suggested by Lee Jones.
>  - Add a new line before the return statement in cros_ec_dev_register().
>    Suggested by Lee Jones.
> 
> Changes since v2: None
> 
> Changes since v1:
>   - Squash patch that adds support to represent EC's as different
>     char devices (e.g: /dev/cros_ec, /dev/cros_pd):
>     https://chromium-review.googlesource.com/#/c/217297/
>     Suggested by Gwendal Grignou
>   - Use cros_ec instead of cros-ec in the subject line to be consistent.
>     Suggested by Gwendal Grignou
> ---
>  drivers/input/keyboard/cros_ec_keyb.c      |   2 +-
>  drivers/mfd/cros_ec.c                      |  59 +++++++++++--
>  drivers/mfd/cros_ec_i2c.c                  |   1 -
>  drivers/mfd/cros_ec_spi.c                  |   1 -
>  drivers/platform/chrome/cros_ec_dev.c      | 128 ++++++++++++++++++++---------
>  drivers/platform/chrome/cros_ec_dev.h      |   7 --
>  drivers/platform/chrome/cros_ec_lightbar.c |  75 +++++++++--------
>  drivers/platform/chrome/cros_ec_lpc.c      |   1 -
>  drivers/platform/chrome/cros_ec_sysfs.c    |  48 +++++------
>  include/linux/mfd/cros_ec.h                |  44 ++++++++--
>  10 files changed, 240 insertions(+), 126 deletions(-)
> 
> diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c
> index 974154a74505..b01966dc7eb3 100644
> --- a/drivers/input/keyboard/cros_ec_keyb.c
> +++ b/drivers/input/keyboard/cros_ec_keyb.c
> @@ -275,7 +275,7 @@ static int cros_ec_keyb_probe(struct platform_device *pdev)
>  	ckdev->dev = dev;
>  	dev_set_drvdata(&pdev->dev, ckdev);
>  
> -	idev->name = ec->ec_name;
> +	idev->name = CROS_EC_DEV_NAME;
>  	idev->phys = ec->phys_name;
>  	__set_bit(EV_REP, idev->evbit);
>  
> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
> index 08d82bfc5268..4fbb4ce8f81e 100644
> --- a/drivers/mfd/cros_ec.c
> +++ b/drivers/mfd/cros_ec.c
> @@ -24,11 +24,29 @@
>  #include <linux/mfd/core.h>
>  #include <linux/mfd/cros_ec.h>
>  
> -static const struct mfd_cell cros_devs[] = {
> -	{
> -		.name = "cros-ec-ctl",
> -		.id = PLATFORM_DEVID_AUTO,
> -	},
> +#define CROS_EC_DEV_EC_INDEX 0
> +#define CROS_EC_DEV_PD_INDEX 1
> +
> +struct cros_ec_platform ec_p = {
> +	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
> +};
> +
> +struct cros_ec_platform pd_p = {
> +	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
> +};
> +
> +struct mfd_cell ec_cell = {
> +	.name = "cros-ec-ctl",
> +	.id = PLATFORM_DEVID_AUTO,
> +	.platform_data = &ec_p,
> +	.pdata_size = sizeof(ec_p),
> +};
> +
> +struct mfd_cell ec_pd_cell = {
> +	.name = "cros-ec-ctl",
> +	.id = PLATFORM_DEVID_AUTO,
> +	.platform_data = &pd_p,
> +	.pdata_size = sizeof(pd_p),
>  };
>  
>  int cros_ec_register(struct cros_ec_device *ec_dev)
> @@ -52,14 +70,39 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
>  
>  	cros_ec_query_all(ec_dev);
>  
> -	err = mfd_add_devices(dev, 0, cros_devs,
> -			      ARRAY_SIZE(cros_devs),
> +	if (IS_ENABLED(CONFIG_OF) && dev->of_node)
> +		ec_p.ec_name = of_get_property(dev->of_node, "devname",
> +					       NULL);

Has this binding already been accepted?  We don't normally allow
"device name"properties in DT.

> +	if (!ec_p.ec_name)
> +		ec_p.ec_name = CROS_EC_DEV_NAME;
> +
> +	err = mfd_add_devices(ec_dev->dev, CROS_EC_DEV_EC_INDEX, &ec_cell, 1,
>  			      NULL, ec_dev->irq, NULL);

Take a look at how 'id' (second argument) is handled in mfd-core, then
try to figure out why what you're doing is not correct.

>  	if (err) {
> -		dev_err(dev, "failed to add mfd devices\n");
> +		dev_err(dev, "failed to add ec\n");
>  		return err;
>  	}

[...]
Javier Martinez Canillas June 3, 2015, 10:12 a.m. UTC | #2
Hello Lee,

Thanks a lot for your feedback.

On 06/03/2015 10:53 AM, Lee Jones wrote:
> On Tue, 02 Jun 2015, Javier Martinez Canillas wrote:
> 
>> From: Gwendal Grignou <gwendal@chromium.org>
>> 
>> Chromebooks can have more than one Embedded Controller so the
>> cros_ec device id has to be incremented for each EC registered.
>> 
>> Add code to handle multiple EC. First ec found is cros-ec0,
>> second cros-ec1 and so on.
>> 
>> Add a new structure to represent multiple EC as different char
>> devices (e.g: /dev/cros_ec, /dev/cros_pd). It connects to
>> cros_ec_device and allows sysfs inferface for cros_pd.
>> 
>> Also reduce number of allocated objects, make chromeos sysfs
>> class object a static and add refcounting to prevent object
>> deletion while command is in progress.
>> 
>> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
>> Reviewed-by: Dmitry Torokhov <dtor@chromium.org>
>> Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
>> ---
>> 
>> Changes since v3:
>>  - Add defines for the EC and PD index constants.
>>  - Remove cros_ec_dev_register() and declare the mfd_cells as static structs.
>>    Suggested by Lee Jones.
>>  - Add a new line before the return statement in cros_ec_dev_register().
>>    Suggested by Lee Jones.
>> 
>> Changes since v2: None
>> 
>> Changes since v1:
>>   - Squash patch that adds support to represent EC's as different
>>     char devices (e.g: /dev/cros_ec, /dev/cros_pd):
>>     https://chromium-review.googlesource.com/#/c/217297/
>>     Suggested by Gwendal Grignou
>>   - Use cros_ec instead of cros-ec in the subject line to be consistent.
>>     Suggested by Gwendal Grignou
>> ---
>>  drivers/input/keyboard/cros_ec_keyb.c      |   2 +-
>>  drivers/mfd/cros_ec.c                      |  59 +++++++++++--
>>  drivers/mfd/cros_ec_i2c.c                  |   1 -
>>  drivers/mfd/cros_ec_spi.c                  |   1 -
>>  drivers/platform/chrome/cros_ec_dev.c      | 128 ++++++++++++++++++++---------
>>  drivers/platform/chrome/cros_ec_dev.h      |   7 --
>>  drivers/platform/chrome/cros_ec_lightbar.c |  75 +++++++++--------
>>  drivers/platform/chrome/cros_ec_lpc.c      |   1 -
>>  drivers/platform/chrome/cros_ec_sysfs.c    |  48 +++++------
>>  include/linux/mfd/cros_ec.h                |  44 ++++++++--
>>  10 files changed, 240 insertions(+), 126 deletions(-)
>> 
>> diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c
>> index 974154a74505..b01966dc7eb3 100644
>> --- a/drivers/input/keyboard/cros_ec_keyb.c
>> +++ b/drivers/input/keyboard/cros_ec_keyb.c
>> @@ -275,7 +275,7 @@ static int cros_ec_keyb_probe(struct platform_device *pdev)
>>  	ckdev->dev = dev;
>>  	dev_set_drvdata(&pdev->dev, ckdev);
>>  
>> -	idev->name = ec->ec_name;
>> +	idev->name = CROS_EC_DEV_NAME;
>>  	idev->phys = ec->phys_name;
>>  	__set_bit(EV_REP, idev->evbit);
>>  
>> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
>> index 08d82bfc5268..4fbb4ce8f81e 100644
>> --- a/drivers/mfd/cros_ec.c
>> +++ b/drivers/mfd/cros_ec.c
>> @@ -24,11 +24,29 @@
>>  #include <linux/mfd/core.h>
>>  #include <linux/mfd/cros_ec.h>
>>  
>> -static const struct mfd_cell cros_devs[] = {
>> -	{
>> -		.name = "cros-ec-ctl",
>> -		.id = PLATFORM_DEVID_AUTO,
>> -	},
>> +#define CROS_EC_DEV_EC_INDEX 0
>> +#define CROS_EC_DEV_PD_INDEX 1
>> +
>> +struct cros_ec_platform ec_p = {
>> +	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
>> +};
>> +
>> +struct cros_ec_platform pd_p = {
>> +	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
>> +};
>> +
>> +struct mfd_cell ec_cell = {
>> +	.name = "cros-ec-ctl",
>> +	.id = PLATFORM_DEVID_AUTO,
>> +	.platform_data = &ec_p,
>> +	.pdata_size = sizeof(ec_p),
>> +};
>> +
>> +struct mfd_cell ec_pd_cell = {
>> +	.name = "cros-ec-ctl",
>> +	.id = PLATFORM_DEVID_AUTO,
>> +	.platform_data = &pd_p,
>> +	.pdata_size = sizeof(pd_p),
>>  };
>>  
>>  int cros_ec_register(struct cros_ec_device *ec_dev)
>> @@ -52,14 +70,39 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
>>  
>>  	cros_ec_query_all(ec_dev);
>>  
>> -	err = mfd_add_devices(dev, 0, cros_devs,
>> -			      ARRAY_SIZE(cros_devs),
>> +	if (IS_ENABLED(CONFIG_OF) && dev->of_node)
>> +		ec_p.ec_name = of_get_property(dev->of_node, "devname",
>> +					       NULL);
> 
> Has this binding already been accepted?  We don't normally allow
> "device name"properties in DT.
> 

Sigh, I now noticed that I missed the DT binding change when originally
forward porting the patches from the downstream ChromiumOS tree. I'm so
sorry about that.

ChromiumOS tree has in Documentation/devicetree/bindings/mfd/cros-ec.txt:

Optional properties (All):
- devname: name of the EC. Can be based on its function: for instance,
  for Sensor Hub, 'cros_sh', for Power Delivery MCU 'cros_pd'.
  If not present, 'cros_ec' can be assumed.

When you say that normally device names are not allowed in DT, do you mean
that "devname" is a too generic property name? (which I totally agree) or
that DT bindings shouldn't have a property to change a device's name for
something more descriptive?

Because for example, the regulator bindings has a "regulator-name" property.
If you agree I can change the property to "google,cros-ec-name" which should
be more precise.

>> +	if (!ec_p.ec_name)
>> +		ec_p.ec_name = CROS_EC_DEV_NAME;
>> +
>> +	err = mfd_add_devices(ec_dev->dev, CROS_EC_DEV_EC_INDEX, &ec_cell, 1,
>>  			      NULL, ec_dev->irq, NULL);
> 
> Take a look at how 'id' (second argument) is handled in mfd-core, then
> try to figure out why what you're doing is not correct.
>

I see, so I should not set the struct mfd_cell .id to PLATFORM_DEVID_AUTO and
just pass PLATFORM_DEVID_AUTO to mfd_add_devices() so platform_device_add()
automatically allocates a device ID and sets pdev->id_auto = true.

It was only working because CROS_EC_DEV_EC_INDEX was zero so id + cell->id
was still PLATFORM_DEVID_AUTO but for CROS_EC_DEV_PD_INDEX, it was set to
PLATFORM_DEVID_NONE...

I'll change that, thanks for pointing it out.

>>  	if (err) {
>> -		dev_err(dev, "failed to add mfd devices\n");
>> +		dev_err(dev, "failed to add ec\n");
>>  		return err;
>>  	}
> 
> [...]
> 

Best regards,
Javier
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Lee Jones June 3, 2015, 11:27 a.m. UTC | #3
On Wed, 03 Jun 2015, Javier Martinez Canillas wrote:

> Hello Lee,
> 
> Thanks a lot for your feedback.
> 
> On 06/03/2015 10:53 AM, Lee Jones wrote:
> > On Tue, 02 Jun 2015, Javier Martinez Canillas wrote:
> > 
> >> From: Gwendal Grignou <gwendal@chromium.org>
> >> 
> >> Chromebooks can have more than one Embedded Controller so the
> >> cros_ec device id has to be incremented for each EC registered.
> >> 
> >> Add code to handle multiple EC. First ec found is cros-ec0,
> >> second cros-ec1 and so on.
> >> 
> >> Add a new structure to represent multiple EC as different char
> >> devices (e.g: /dev/cros_ec, /dev/cros_pd). It connects to
> >> cros_ec_device and allows sysfs inferface for cros_pd.
> >> 
> >> Also reduce number of allocated objects, make chromeos sysfs
> >> class object a static and add refcounting to prevent object
> >> deletion while command is in progress.
> >> 
> >> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> >> Reviewed-by: Dmitry Torokhov <dtor@chromium.org>
> >> Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
> >> ---
> >> 
> >> Changes since v3:
> >>  - Add defines for the EC and PD index constants.
> >>  - Remove cros_ec_dev_register() and declare the mfd_cells as static structs.
> >>    Suggested by Lee Jones.
> >>  - Add a new line before the return statement in cros_ec_dev_register().
> >>    Suggested by Lee Jones.
> >> 
> >> Changes since v2: None
> >> 
> >> Changes since v1:
> >>   - Squash patch that adds support to represent EC's as different
> >>     char devices (e.g: /dev/cros_ec, /dev/cros_pd):
> >>     https://chromium-review.googlesource.com/#/c/217297/
> >>     Suggested by Gwendal Grignou
> >>   - Use cros_ec instead of cros-ec in the subject line to be consistent.
> >>     Suggested by Gwendal Grignou
> >> ---
> >>  drivers/input/keyboard/cros_ec_keyb.c      |   2 +-
> >>  drivers/mfd/cros_ec.c                      |  59 +++++++++++--
> >>  drivers/mfd/cros_ec_i2c.c                  |   1 -
> >>  drivers/mfd/cros_ec_spi.c                  |   1 -
> >>  drivers/platform/chrome/cros_ec_dev.c      | 128 ++++++++++++++++++++---------
> >>  drivers/platform/chrome/cros_ec_dev.h      |   7 --
> >>  drivers/platform/chrome/cros_ec_lightbar.c |  75 +++++++++--------
> >>  drivers/platform/chrome/cros_ec_lpc.c      |   1 -
> >>  drivers/platform/chrome/cros_ec_sysfs.c    |  48 +++++------
> >>  include/linux/mfd/cros_ec.h                |  44 ++++++++--
> >>  10 files changed, 240 insertions(+), 126 deletions(-)
> >> 
> >> diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c
> >> index 974154a74505..b01966dc7eb3 100644
> >> --- a/drivers/input/keyboard/cros_ec_keyb.c
> >> +++ b/drivers/input/keyboard/cros_ec_keyb.c
> >> @@ -275,7 +275,7 @@ static int cros_ec_keyb_probe(struct platform_device *pdev)
> >>  	ckdev->dev = dev;
> >>  	dev_set_drvdata(&pdev->dev, ckdev);
> >>  
> >> -	idev->name = ec->ec_name;
> >> +	idev->name = CROS_EC_DEV_NAME;
> >>  	idev->phys = ec->phys_name;
> >>  	__set_bit(EV_REP, idev->evbit);
> >>  
> >> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
> >> index 08d82bfc5268..4fbb4ce8f81e 100644
> >> --- a/drivers/mfd/cros_ec.c
> >> +++ b/drivers/mfd/cros_ec.c
> >> @@ -24,11 +24,29 @@
> >>  #include <linux/mfd/core.h>
> >>  #include <linux/mfd/cros_ec.h>
> >>  
> >> -static const struct mfd_cell cros_devs[] = {
> >> -	{
> >> -		.name = "cros-ec-ctl",
> >> -		.id = PLATFORM_DEVID_AUTO,
> >> -	},
> >> +#define CROS_EC_DEV_EC_INDEX 0
> >> +#define CROS_EC_DEV_PD_INDEX 1
> >> +
> >> +struct cros_ec_platform ec_p = {
> >> +	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
> >> +};
> >> +
> >> +struct cros_ec_platform pd_p = {
> >> +	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
> >> +};
> >> +
> >> +struct mfd_cell ec_cell = {
> >> +	.name = "cros-ec-ctl",
> >> +	.id = PLATFORM_DEVID_AUTO,
> >> +	.platform_data = &ec_p,
> >> +	.pdata_size = sizeof(ec_p),
> >> +};
> >> +
> >> +struct mfd_cell ec_pd_cell = {
> >> +	.name = "cros-ec-ctl",
> >> +	.id = PLATFORM_DEVID_AUTO,
> >> +	.platform_data = &pd_p,
> >> +	.pdata_size = sizeof(pd_p),
> >>  };
> >>  
> >>  int cros_ec_register(struct cros_ec_device *ec_dev)
> >> @@ -52,14 +70,39 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
> >>  
> >>  	cros_ec_query_all(ec_dev);
> >>  
> >> -	err = mfd_add_devices(dev, 0, cros_devs,
> >> -			      ARRAY_SIZE(cros_devs),
> >> +	if (IS_ENABLED(CONFIG_OF) && dev->of_node)
> >> +		ec_p.ec_name = of_get_property(dev->of_node, "devname",
> >> +					       NULL);
> > 
> > Has this binding already been accepted?  We don't normally allow
> > "device name"properties in DT.
> > 
> 
> Sigh, I now noticed that I missed the DT binding change when originally
> forward porting the patches from the downstream ChromiumOS tree. I'm so
> sorry about that.
> 
> ChromiumOS tree has in Documentation/devicetree/bindings/mfd/cros-ec.txt:
> 
> Optional properties (All):
> - devname: name of the EC. Can be based on its function: for instance,
>   for Sensor Hub, 'cros_sh', for Power Delivery MCU 'cros_pd'.
>   If not present, 'cros_ec' can be assumed.
> 
> When you say that normally device names are not allowed in DT, do you mean
> that "devname" is a too generic property name? (which I totally agree) or
> that DT bindings shouldn't have a property to change a device's name for
> something more descriptive?
> 
> Because for example, the regulator bindings has a "regulator-name" property.
> If you agree I can change the property to "google,cros-ec-name" which should
> be more precise.

I mean, no names of devices are allowed in Device Tree:

  `git grep name -- arch/arm/boot/dts/ | grep dev`

> >> +	if (!ec_p.ec_name)
> >> +		ec_p.ec_name = CROS_EC_DEV_NAME;
> >> +
> >> +	err = mfd_add_devices(ec_dev->dev, CROS_EC_DEV_EC_INDEX, &ec_cell, 1,
> >>  			      NULL, ec_dev->irq, NULL);
> > 
> > Take a look at how 'id' (second argument) is handled in mfd-core, then
> > try to figure out why what you're doing is not correct.
> >
> 
> I see, so I should not set the struct mfd_cell .id to PLATFORM_DEVID_AUTO and
> just pass PLATFORM_DEVID_AUTO to mfd_add_devices() so platform_device_add()
> automatically allocates a device ID and sets pdev->id_auto = true.
> 
> It was only working because CROS_EC_DEV_EC_INDEX was zero so id + cell->id
> was still PLATFORM_DEVID_AUTO but for CROS_EC_DEV_PD_INDEX, it was set to
> PLATFORM_DEVID_NONE...
> 
> I'll change that, thanks for pointing it out.

No problem
Javier Martinez Canillas June 3, 2015, 11:49 a.m. UTC | #4
Hello Lee,

On 06/03/2015 01:27 PM, Lee Jones wrote:
> On Wed, 03 Jun 2015, Javier Martinez Canillas wrote:

[snip]

>> >>  
>> >> -	err = mfd_add_devices(dev, 0, cros_devs,
>> >> -			      ARRAY_SIZE(cros_devs),
>> >> +	if (IS_ENABLED(CONFIG_OF) && dev->of_node)
>> >> +		ec_p.ec_name = of_get_property(dev->of_node, "devname",
>> >> +					       NULL);
>> > 
>> > Has this binding already been accepted?  We don't normally allow
>> > "device name"properties in DT.
>> > 
>> 
>> Sigh, I now noticed that I missed the DT binding change when originally
>> forward porting the patches from the downstream ChromiumOS tree. I'm so
>> sorry about that.
>> 
>> ChromiumOS tree has in Documentation/devicetree/bindings/mfd/cros-ec.txt:
>> 
>> Optional properties (All):
>> - devname: name of the EC. Can be based on its function: for instance,
>>   for Sensor Hub, 'cros_sh', for Power Delivery MCU 'cros_pd'.
>>   If not present, 'cros_ec' can be assumed.
>> 
>> When you say that normally device names are not allowed in DT, do you mean
>> that "devname" is a too generic property name? (which I totally agree) or
>> that DT bindings shouldn't have a property to change a device's name for
>> something more descriptive?
>> 
>> Because for example, the regulator bindings has a "regulator-name" property.
>> If you agree I can change the property to "google,cros-ec-name" which should
>> be more precise.
> 
> I mean, no names of devices are allowed in Device Tree:
> 
>   `git grep name -- arch/arm/boot/dts/ | grep dev`
> 

Ok, but do you agree on having a "google,cros-ec-name" (with no dev on it)
property to define the resource name just like regulators have "regulator-name"
that changes what is shown in /sys/kernel/debug/regulator/$name?

Otherwise all the EC's will be named cros_ec or regardless of their function
and this is shown in both /dev/$name and /sys/class/chromeos/$name.

Best regards,
Javier
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diff mbox

Patch

diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c
index 974154a74505..b01966dc7eb3 100644
--- a/drivers/input/keyboard/cros_ec_keyb.c
+++ b/drivers/input/keyboard/cros_ec_keyb.c
@@ -275,7 +275,7 @@  static int cros_ec_keyb_probe(struct platform_device *pdev)
 	ckdev->dev = dev;
 	dev_set_drvdata(&pdev->dev, ckdev);
 
-	idev->name = ec->ec_name;
+	idev->name = CROS_EC_DEV_NAME;
 	idev->phys = ec->phys_name;
 	__set_bit(EV_REP, idev->evbit);
 
diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index 08d82bfc5268..4fbb4ce8f81e 100644
--- a/drivers/mfd/cros_ec.c
+++ b/drivers/mfd/cros_ec.c
@@ -24,11 +24,29 @@ 
 #include <linux/mfd/core.h>
 #include <linux/mfd/cros_ec.h>
 
-static const struct mfd_cell cros_devs[] = {
-	{
-		.name = "cros-ec-ctl",
-		.id = PLATFORM_DEVID_AUTO,
-	},
+#define CROS_EC_DEV_EC_INDEX 0
+#define CROS_EC_DEV_PD_INDEX 1
+
+struct cros_ec_platform ec_p = {
+	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
+};
+
+struct cros_ec_platform pd_p = {
+	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
+};
+
+struct mfd_cell ec_cell = {
+	.name = "cros-ec-ctl",
+	.id = PLATFORM_DEVID_AUTO,
+	.platform_data = &ec_p,
+	.pdata_size = sizeof(ec_p),
+};
+
+struct mfd_cell ec_pd_cell = {
+	.name = "cros-ec-ctl",
+	.id = PLATFORM_DEVID_AUTO,
+	.platform_data = &pd_p,
+	.pdata_size = sizeof(pd_p),
 };
 
 int cros_ec_register(struct cros_ec_device *ec_dev)
@@ -52,14 +70,39 @@  int cros_ec_register(struct cros_ec_device *ec_dev)
 
 	cros_ec_query_all(ec_dev);
 
-	err = mfd_add_devices(dev, 0, cros_devs,
-			      ARRAY_SIZE(cros_devs),
+	if (IS_ENABLED(CONFIG_OF) && dev->of_node)
+		ec_p.ec_name = of_get_property(dev->of_node, "devname",
+					       NULL);
+
+	if (!ec_p.ec_name)
+		ec_p.ec_name = CROS_EC_DEV_NAME;
+
+	err = mfd_add_devices(ec_dev->dev, CROS_EC_DEV_EC_INDEX, &ec_cell, 1,
 			      NULL, ec_dev->irq, NULL);
 	if (err) {
-		dev_err(dev, "failed to add mfd devices\n");
+		dev_err(dev, "failed to add ec\n");
 		return err;
 	}
 
+	if (ec_dev->max_passthru) {
+		/*
+		 * Register a PD device as well on top of this device.
+		 * We make the following assumptions:
+		 * - behind an EC, we have a pd
+		 * - only one device added.
+		 * - the EC is responsive at init time (it is not true for a
+		 *   sensor hub.
+		 */
+		pd_p.ec_name = CROS_EC_DEV_PD_NAME;
+
+		err = mfd_add_devices(ec_dev->dev, CROS_EC_DEV_PD_INDEX,
+				      &ec_pd_cell, 1, NULL, ec_dev->irq, NULL);
+		if (err) {
+			dev_err(dev, "failed to add pd ec\n");
+			return err;
+		}
+	}
+
 	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
 		err = of_platform_populate(dev->of_node, NULL, NULL, dev);
 		if (err) {
diff --git a/drivers/mfd/cros_ec_i2c.c b/drivers/mfd/cros_ec_i2c.c
index 22e8a4ae1711..b9a0963ca5c3 100644
--- a/drivers/mfd/cros_ec_i2c.c
+++ b/drivers/mfd/cros_ec_i2c.c
@@ -302,7 +302,6 @@  static int cros_ec_i2c_probe(struct i2c_client *client,
 	ec_dev->irq = client->irq;
 	ec_dev->cmd_xfer = cros_ec_cmd_xfer_i2c;
 	ec_dev->pkt_xfer = cros_ec_pkt_xfer_i2c;
-	ec_dev->ec_name = client->name;
 	ec_dev->phys_name = client->adapter->name;
 	ec_dev->din_size = sizeof(struct ec_host_response_i2c) +
 			   sizeof(struct ec_response_get_protocol_info);
diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c
index 4e6f2f6b1095..faba03e2f1ef 100644
--- a/drivers/mfd/cros_ec_spi.c
+++ b/drivers/mfd/cros_ec_spi.c
@@ -637,7 +637,6 @@  static int cros_ec_spi_probe(struct spi_device *spi)
 	ec_dev->irq = spi->irq;
 	ec_dev->cmd_xfer = cros_ec_cmd_xfer_spi;
 	ec_dev->pkt_xfer = cros_ec_pkt_xfer_spi;
-	ec_dev->ec_name = ec_spi->spi->modalias;
 	ec_dev->phys_name = dev_name(&ec_spi->spi->dev);
 	ec_dev->din_size = EC_MSG_PREAMBLE_COUNT +
 			   sizeof(struct ec_host_response) +
diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
index 14111e32658b..4b636cc84171 100644
--- a/drivers/platform/chrome/cros_ec_dev.c
+++ b/drivers/platform/chrome/cros_ec_dev.c
@@ -27,11 +27,22 @@ 
 
 /* Device variables */
 #define CROS_MAX_DEV 128
-static struct class *cros_class;
 static int ec_major;
 
+static const struct attribute_group *cros_ec_groups[] = {
+	&cros_ec_attr_group,
+	&cros_ec_lightbar_attr_group,
+	NULL,
+};
+
+static struct class cros_class = {
+	.owner          = THIS_MODULE,
+	.name           = "chromeos",
+	.dev_groups     = cros_ec_groups,
+};
+
 /* Basic communication */
-static int ec_get_version(struct cros_ec_device *ec, char *str, int maxlen)
+static int ec_get_version(struct cros_ec_dev *ec, char *str, int maxlen)
 {
 	struct ec_response_get_version *resp;
 	static const char * const current_image_name[] = {
@@ -49,7 +60,7 @@  static int ec_get_version(struct cros_ec_device *ec, char *str, int maxlen)
 	msg->insize = sizeof(*resp);
 	msg->outsize = 0;
 
-	ret = cros_ec_cmd_xfer(ec, msg);
+	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0)
 		goto exit;
 
@@ -78,8 +89,10 @@  exit:
 /* Device file ops */
 static int ec_device_open(struct inode *inode, struct file *filp)
 {
-	filp->private_data = container_of(inode->i_cdev,
-					  struct cros_ec_device, cdev);
+	struct cros_ec_dev *ec = container_of(inode->i_cdev,
+					      struct cros_ec_dev, cdev);
+	filp->private_data = ec;
+	nonseekable_open(inode, filp);
 	return 0;
 }
 
@@ -91,7 +104,7 @@  static int ec_device_release(struct inode *inode, struct file *filp)
 static ssize_t ec_device_read(struct file *filp, char __user *buffer,
 			      size_t length, loff_t *offset)
 {
-	struct cros_ec_device *ec = filp->private_data;
+	struct cros_ec_dev *ec = filp->private_data;
 	char msg[sizeof(struct ec_response_get_version) +
 		 sizeof(CROS_EC_DEV_VERSION)];
 	size_t count;
@@ -114,7 +127,7 @@  static ssize_t ec_device_read(struct file *filp, char __user *buffer,
 }
 
 /* Ioctls */
-static long ec_device_ioctl_xcmd(struct cros_ec_device *ec, void __user *arg)
+static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
 {
 	long ret;
 	struct cros_ec_command u_cmd;
@@ -133,7 +146,8 @@  static long ec_device_ioctl_xcmd(struct cros_ec_device *ec, void __user *arg)
 		goto exit;
 	}
 
-	ret = cros_ec_cmd_xfer(ec, s_cmd);
+	s_cmd->command += ec->cmd_offset;
+	ret = cros_ec_cmd_xfer(ec->ec_dev, s_cmd);
 	/* Only copy data to userland if data was received. */
 	if (ret < 0)
 		goto exit;
@@ -145,19 +159,21 @@  exit:
 	return ret;
 }
 
-static long ec_device_ioctl_readmem(struct cros_ec_device *ec, void __user *arg)
+static long ec_device_ioctl_readmem(struct cros_ec_dev *ec, void __user *arg)
 {
+	struct cros_ec_device *ec_dev = ec->ec_dev;
 	struct cros_ec_readmem s_mem = { };
 	long num;
 
 	/* Not every platform supports direct reads */
-	if (!ec->cmd_readmem)
+	if (!ec_dev->cmd_readmem)
 		return -ENOTTY;
 
 	if (copy_from_user(&s_mem, arg, sizeof(s_mem)))
 		return -EFAULT;
 
-	num = ec->cmd_readmem(ec, s_mem.offset, s_mem.bytes, s_mem.buffer);
+	num = ec_dev->cmd_readmem(ec_dev, s_mem.offset, s_mem.bytes,
+				  s_mem.buffer);
 	if (num <= 0)
 		return num;
 
@@ -170,7 +186,7 @@  static long ec_device_ioctl_readmem(struct cros_ec_device *ec, void __user *arg)
 static long ec_device_ioctl(struct file *filp, unsigned int cmd,
 			    unsigned long arg)
 {
-	struct cros_ec_device *ec = filp->private_data;
+	struct cros_ec_dev *ec = filp->private_data;
 
 	if (_IOC_TYPE(cmd) != CROS_EC_DEV_IOC)
 		return -ENOTTY;
@@ -193,45 +209,81 @@  static const struct file_operations fops = {
 	.unlocked_ioctl = ec_device_ioctl,
 };
 
+static void __remove(struct device *dev)
+{
+	struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev,
+					      class_dev);
+	kfree(ec);
+}
+
 static int ec_device_probe(struct platform_device *pdev)
 {
-	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
-	int retval = -ENOTTY;
-	dev_t devno = MKDEV(ec_major, 0);
+	int retval = -ENOMEM;
+	struct device *dev = &pdev->dev;
+	struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
+	dev_t devno = MKDEV(ec_major, pdev->id);
+	struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
+
+	if (!ec)
+		return retval;
 
-	/* Instantiate it (and remember the EC) */
+	dev_set_drvdata(dev, ec);
+	ec->ec_dev = dev_get_drvdata(dev->parent);
+	ec->dev = dev;
+	ec->cmd_offset = ec_platform->cmd_offset;
+	device_initialize(&ec->class_dev);
 	cdev_init(&ec->cdev, &fops);
 
+	/*
+	 * Add the character device
+	 * Link cdev to the class device to be sure device is not used
+	 * before unbinding it.
+	 */
+	ec->cdev.kobj.parent = &ec->class_dev.kobj;
 	retval = cdev_add(&ec->cdev, devno, 1);
 	if (retval) {
-		dev_err(&pdev->dev, ": failed to add character device\n");
-		return retval;
+		dev_err(dev, ": failed to add character device\n");
+		goto cdev_add_failed;
 	}
 
-	ec->vdev = device_create(cros_class, NULL, devno, ec,
-				 CROS_EC_DEV_NAME);
-	if (IS_ERR(ec->vdev)) {
-		retval = PTR_ERR(ec->vdev);
-		dev_err(&pdev->dev, ": failed to create device\n");
-		cdev_del(&ec->cdev);
-		return retval;
+	/*
+	 * Add the class device
+	 * Link to the character device for creating the /dev entry
+	 * in devtmpfs.
+	 */
+	ec->class_dev.devt = ec->cdev.dev;
+	ec->class_dev.class = &cros_class;
+	ec->class_dev.parent = dev;
+	ec->class_dev.release = __remove;
+
+	retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
+	if (retval) {
+		dev_err(dev, "dev_set_name failed => %d\n", retval);
+		goto set_named_failed;
 	}
 
-	/* Initialize extra interfaces */
-	ec_dev_sysfs_init(ec);
-	ec_dev_lightbar_init(ec);
+	retval = device_add(&ec->class_dev);
+	if (retval) {
+		dev_err(dev, "device_register failed => %d\n", retval);
+		goto dev_reg_failed;
+	}
 
 	return 0;
+
+dev_reg_failed:
+set_named_failed:
+	dev_set_drvdata(dev, NULL);
+	cdev_del(&ec->cdev);
+cdev_add_failed:
+	kfree(ec);
+	return retval;
 }
 
 static int ec_device_remove(struct platform_device *pdev)
 {
-	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
-
-	ec_dev_lightbar_remove(ec);
-	ec_dev_sysfs_remove(ec);
-	device_destroy(cros_class, MKDEV(ec_major, 0));
+	struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
 	cdev_del(&ec->cdev);
+	device_unregister(&ec->class_dev);
 	return 0;
 }
 
@@ -254,10 +306,10 @@  static int __init cros_ec_dev_init(void)
 	int ret;
 	dev_t dev = 0;
 
-	cros_class = class_create(THIS_MODULE, "chromeos");
-	if (IS_ERR(cros_class)) {
+	ret  = class_register(&cros_class);
+	if (ret) {
 		pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
-		return PTR_ERR(cros_class);
+		return ret;
 	}
 
 	/* Get a range of minor numbers (starting with 0) to work with */
@@ -279,7 +331,7 @@  static int __init cros_ec_dev_init(void)
 failed_devreg:
 	unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV);
 failed_chrdevreg:
-	class_destroy(cros_class);
+	class_unregister(&cros_class);
 	return ret;
 }
 
@@ -287,7 +339,7 @@  static void __exit cros_ec_dev_exit(void)
 {
 	platform_driver_unregister(&cros_ec_dev_driver);
 	unregister_chrdev(ec_major, CROS_EC_DEV_NAME);
-	class_destroy(cros_class);
+	class_unregister(&cros_class);
 }
 
 module_init(cros_ec_dev_init);
diff --git a/drivers/platform/chrome/cros_ec_dev.h b/drivers/platform/chrome/cros_ec_dev.h
index 45d67f7e518c..bfd2c84c3571 100644
--- a/drivers/platform/chrome/cros_ec_dev.h
+++ b/drivers/platform/chrome/cros_ec_dev.h
@@ -24,7 +24,6 @@ 
 #include <linux/types.h>
 #include <linux/mfd/cros_ec.h>
 
-#define CROS_EC_DEV_NAME "cros_ec"
 #define CROS_EC_DEV_VERSION "1.0.0"
 
 /*
@@ -44,10 +43,4 @@  struct cros_ec_readmem {
 #define CROS_EC_DEV_IOCXCMD   _IOWR(CROS_EC_DEV_IOC, 0, struct cros_ec_command)
 #define CROS_EC_DEV_IOCRDMEM  _IOWR(CROS_EC_DEV_IOC, 1, struct cros_ec_readmem)
 
-void ec_dev_sysfs_init(struct cros_ec_device *);
-void ec_dev_sysfs_remove(struct cros_ec_device *);
-
-void ec_dev_lightbar_init(struct cros_ec_device *);
-void ec_dev_lightbar_remove(struct cros_ec_device *);
-
 #endif /* _CROS_EC_DEV_H_ */
diff --git a/drivers/platform/chrome/cros_ec_lightbar.c b/drivers/platform/chrome/cros_ec_lightbar.c
index 6e1986a2dce1..144e09df9b84 100644
--- a/drivers/platform/chrome/cros_ec_lightbar.c
+++ b/drivers/platform/chrome/cros_ec_lightbar.c
@@ -92,7 +92,7 @@  out:
 	return ret;
 }
 
-static struct cros_ec_command *alloc_lightbar_cmd_msg(void)
+static struct cros_ec_command *alloc_lightbar_cmd_msg(struct cros_ec_dev *ec)
 {
 	struct cros_ec_command *msg;
 	int len;
@@ -105,14 +105,14 @@  static struct cros_ec_command *alloc_lightbar_cmd_msg(void)
 		return NULL;
 
 	msg->version = 0;
-	msg->command = EC_CMD_LIGHTBAR_CMD;
+	msg->command = EC_CMD_LIGHTBAR_CMD + ec->cmd_offset;
 	msg->outsize = sizeof(struct ec_params_lightbar);
 	msg->insize = sizeof(struct ec_response_lightbar);
 
 	return msg;
 }
 
-static int get_lightbar_version(struct cros_ec_device *ec,
+static int get_lightbar_version(struct cros_ec_dev *ec,
 				uint32_t *ver_ptr, uint32_t *flg_ptr)
 {
 	struct ec_params_lightbar *param;
@@ -120,13 +120,13 @@  static int get_lightbar_version(struct cros_ec_device *ec,
 	struct cros_ec_command *msg;
 	int ret;
 
-	msg = alloc_lightbar_cmd_msg();
+	msg = alloc_lightbar_cmd_msg(ec);
 	if (!msg)
 		return 0;
 
 	param = (struct ec_params_lightbar *)msg->data;
 	param->cmd = LIGHTBAR_CMD_VERSION;
-	ret = cros_ec_cmd_xfer(ec, msg);
+	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0) {
 		ret = 0;
 		goto exit;
@@ -165,7 +165,8 @@  static ssize_t version_show(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
 	uint32_t version = 0, flags = 0;
-	struct cros_ec_device *ec = dev_get_drvdata(dev);
+	struct cros_ec_dev *ec = container_of(dev,
+					      struct cros_ec_dev, class_dev);
 	int ret;
 
 	ret = lb_throttle();
@@ -187,12 +188,13 @@  static ssize_t brightness_store(struct device *dev,
 	struct cros_ec_command *msg;
 	int ret;
 	unsigned int val;
-	struct cros_ec_device *ec = dev_get_drvdata(dev);
+	struct cros_ec_dev *ec = container_of(dev,
+					      struct cros_ec_dev, class_dev);
 
 	if (kstrtouint(buf, 0, &val))
 		return -EINVAL;
 
-	msg = alloc_lightbar_cmd_msg();
+	msg = alloc_lightbar_cmd_msg(ec);
 	if (!msg)
 		return -ENOMEM;
 
@@ -203,7 +205,7 @@  static ssize_t brightness_store(struct device *dev,
 	if (ret)
 		goto exit;
 
-	ret = cros_ec_cmd_xfer(ec, msg);
+	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0)
 		goto exit;
 
@@ -231,11 +233,12 @@  static ssize_t led_rgb_store(struct device *dev, struct device_attribute *attr,
 {
 	struct ec_params_lightbar *param;
 	struct cros_ec_command *msg;
-	struct cros_ec_device *ec = dev_get_drvdata(dev);
+	struct cros_ec_dev *ec = container_of(dev,
+					      struct cros_ec_dev, class_dev);
 	unsigned int val[4];
 	int ret, i = 0, j = 0, ok = 0;
 
-	msg = alloc_lightbar_cmd_msg();
+	msg = alloc_lightbar_cmd_msg(ec);
 	if (!msg)
 		return -ENOMEM;
 
@@ -268,7 +271,7 @@  static ssize_t led_rgb_store(struct device *dev, struct device_attribute *attr,
 					return ret;
 			}
 
-			ret = cros_ec_cmd_xfer(ec, msg);
+			ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 			if (ret < 0)
 				goto exit;
 
@@ -304,9 +307,10 @@  static ssize_t sequence_show(struct device *dev,
 	struct ec_response_lightbar *resp;
 	struct cros_ec_command *msg;
 	int ret;
-	struct cros_ec_device *ec = dev_get_drvdata(dev);
+	struct cros_ec_dev *ec = container_of(dev,
+					      struct cros_ec_dev, class_dev);
 
-	msg = alloc_lightbar_cmd_msg();
+	msg = alloc_lightbar_cmd_msg(ec);
 	if (!msg)
 		return -ENOMEM;
 
@@ -316,7 +320,7 @@  static ssize_t sequence_show(struct device *dev,
 	if (ret)
 		goto exit;
 
-	ret = cros_ec_cmd_xfer(ec, msg);
+	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0)
 		goto exit;
 
@@ -345,9 +349,10 @@  static ssize_t sequence_store(struct device *dev, struct device_attribute *attr,
 	struct cros_ec_command *msg;
 	unsigned int num;
 	int ret, len;
-	struct cros_ec_device *ec = dev_get_drvdata(dev);
+	struct cros_ec_dev *ec = container_of(dev,
+					      struct cros_ec_dev, class_dev);
 
-	msg = alloc_lightbar_cmd_msg();
+	msg = alloc_lightbar_cmd_msg(ec);
 	if (!msg)
 		return -ENOMEM;
 
@@ -372,7 +377,7 @@  static ssize_t sequence_store(struct device *dev, struct device_attribute *attr,
 	if (ret)
 		return ret;
 
-	ret = cros_ec_cmd_xfer(ec, msg);
+	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0)
 		return ret;
 
@@ -397,25 +402,27 @@  static struct attribute *__lb_cmds_attrs[] = {
 	&dev_attr_sequence.attr,
 	NULL,
 };
-static struct attribute_group lb_cmds_attr_group = {
-	.name = "lightbar",
-	.attrs = __lb_cmds_attrs,
-};
 
-void ec_dev_lightbar_init(struct cros_ec_device *ec)
+static umode_t cros_ec_lightbar_attrs_are_visible(struct kobject *kobj,
+						  struct attribute *a, int n)
 {
-	int ret = 0;
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct cros_ec_dev *ec = container_of(dev,
+					      struct cros_ec_dev, class_dev);
+	struct platform_device *pdev = container_of(ec->dev,
+						   struct platform_device, dev);
+	if (pdev->id != 0)
+		return 0;
 
 	/* Only instantiate this stuff if the EC has a lightbar */
-	if (!get_lightbar_version(ec, NULL, NULL))
-		return;
-
-	ret = sysfs_create_group(&ec->vdev->kobj, &lb_cmds_attr_group);
-	if (ret)
-		pr_warn("sysfs_create_group() failed: %d\n", ret);
+	if (get_lightbar_version(ec, NULL, NULL))
+		return a->mode;
+	else
+		return 0;
 }
 
-void ec_dev_lightbar_remove(struct cros_ec_device *ec)
-{
-	sysfs_remove_group(&ec->vdev->kobj, &lb_cmds_attr_group);
-}
+struct attribute_group cros_ec_lightbar_attr_group = {
+	.name = "lightbar",
+	.attrs = __lb_cmds_attrs,
+	.is_visible = cros_ec_lightbar_attrs_are_visible,
+};
diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
index 92b633324aaa..f9a245465fd0 100644
--- a/drivers/platform/chrome/cros_ec_lpc.c
+++ b/drivers/platform/chrome/cros_ec_lpc.c
@@ -273,7 +273,6 @@  static int cros_ec_lpc_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, ec_dev);
 	ec_dev->dev = dev;
-	ec_dev->ec_name = pdev->name;
 	ec_dev->phys_name = dev_name(dev);
 	ec_dev->cmd_xfer = cros_ec_cmd_xfer_lpc;
 	ec_dev->pkt_xfer = cros_ec_pkt_xfer_lpc;
diff --git a/drivers/platform/chrome/cros_ec_sysfs.c b/drivers/platform/chrome/cros_ec_sysfs.c
index 78ba82d670cb..f3baf9973989 100644
--- a/drivers/platform/chrome/cros_ec_sysfs.c
+++ b/drivers/platform/chrome/cros_ec_sysfs.c
@@ -72,7 +72,8 @@  static ssize_t store_ec_reboot(struct device *dev,
 	int got_cmd = 0, offset = 0;
 	int i;
 	int ret;
-	struct cros_ec_device *ec = dev_get_drvdata(dev);
+	struct cros_ec_dev *ec = container_of(dev,
+					      struct cros_ec_dev, class_dev);
 
 	msg = kmalloc(sizeof(*msg) + sizeof(*param), GFP_KERNEL);
 	if (!msg)
@@ -112,10 +113,10 @@  static ssize_t store_ec_reboot(struct device *dev,
 	}
 
 	msg->version = 0;
-	msg->command = EC_CMD_REBOOT_EC;
+	msg->command = EC_CMD_REBOOT_EC + ec->cmd_offset;
 	msg->outsize = sizeof(*param);
 	msg->insize = 0;
-	ret = cros_ec_cmd_xfer(ec, msg);
+	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0) {
 		count = ret;
 		goto exit;
@@ -139,7 +140,8 @@  static ssize_t show_ec_version(struct device *dev,
 	struct cros_ec_command *msg;
 	int ret;
 	int count = 0;
-	struct cros_ec_device *ec = dev_get_drvdata(dev);
+	struct cros_ec_dev *ec = container_of(dev,
+					      struct cros_ec_dev, class_dev);
 
 	msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
 	if (!msg)
@@ -147,10 +149,10 @@  static ssize_t show_ec_version(struct device *dev,
 
 	/* Get versions. RW may change. */
 	msg->version = 0;
-	msg->command = EC_CMD_GET_VERSION;
+	msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
 	msg->insize = sizeof(*r_ver);
 	msg->outsize = 0;
-	ret = cros_ec_cmd_xfer(ec, msg);
+	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0) {
 		count = ret;
 		goto exit;
@@ -175,9 +177,9 @@  static ssize_t show_ec_version(struct device *dev,
 			    image_names[r_ver->current_image] : "?"));
 
 	/* Get build info. */
-	msg->command = EC_CMD_GET_BUILD_INFO;
+	msg->command = EC_CMD_GET_BUILD_INFO + ec->cmd_offset;
 	msg->insize = EC_HOST_PARAM_SIZE;
-	ret = cros_ec_cmd_xfer(ec, msg);
+	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0)
 		count += scnprintf(buf + count, PAGE_SIZE - count,
 				   "Build info:    XFER ERROR %d\n", ret);
@@ -191,9 +193,9 @@  static ssize_t show_ec_version(struct device *dev,
 	}
 
 	/* Get chip info. */
-	msg->command = EC_CMD_GET_CHIP_INFO;
+	msg->command = EC_CMD_GET_CHIP_INFO + ec->cmd_offset;
 	msg->insize = sizeof(*r_chip);
-	ret = cros_ec_cmd_xfer(ec, msg);
+	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0)
 		count += scnprintf(buf + count, PAGE_SIZE - count,
 				   "Chip info:     XFER ERROR %d\n", ret);
@@ -215,9 +217,9 @@  static ssize_t show_ec_version(struct device *dev,
 	}
 
 	/* Get board version */
-	msg->command = EC_CMD_GET_BOARD_VERSION;
+	msg->command = EC_CMD_GET_BOARD_VERSION + ec->cmd_offset;
 	msg->insize = sizeof(*r_board);
-	ret = cros_ec_cmd_xfer(ec, msg);
+	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0)
 		count += scnprintf(buf + count, PAGE_SIZE - count,
 				   "Board version: XFER ERROR %d\n", ret);
@@ -243,7 +245,8 @@  static ssize_t show_ec_flashinfo(struct device *dev,
 	struct ec_response_flash_info *resp;
 	struct cros_ec_command *msg;
 	int ret;
-	struct cros_ec_device *ec = dev_get_drvdata(dev);
+	struct cros_ec_dev *ec = container_of(dev,
+					      struct cros_ec_dev, class_dev);
 
 	msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
 	if (!msg)
@@ -251,10 +254,10 @@  static ssize_t show_ec_flashinfo(struct device *dev,
 
 	/* The flash info shouldn't ever change, but ask each time anyway. */
 	msg->version = 0;
-	msg->command = EC_CMD_FLASH_INFO;
+	msg->command = EC_CMD_FLASH_INFO + ec->cmd_offset;
 	msg->insize = sizeof(*resp);
 	msg->outsize = 0;
-	ret = cros_ec_cmd_xfer(ec, msg);
+	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
 	if (ret < 0)
 		goto exit;
 	if (msg->result != EC_RES_SUCCESS) {
@@ -288,20 +291,7 @@  static struct attribute *__ec_attrs[] = {
 	NULL,
 };
 
-static struct attribute_group ec_attr_group = {
+struct attribute_group cros_ec_attr_group = {
 	.attrs = __ec_attrs,
 };
 
-void ec_dev_sysfs_init(struct cros_ec_device *ec)
-{
-	int error;
-
-	error = sysfs_create_group(&ec->vdev->kobj, &ec_attr_group);
-	if (error)
-		pr_warn("failed to create group: %d\n", error);
-}
-
-void ec_dev_sysfs_remove(struct cros_ec_device *ec)
-{
-	sysfs_remove_group(&ec->vdev->kobj, &ec_attr_group);
-}
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 92e13aaa450c..da72671a42fa 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -17,10 +17,14 @@ 
 #define __LINUX_MFD_CROS_EC_H
 
 #include <linux/cdev.h>
+#include <linux/device.h>
 #include <linux/notifier.h>
 #include <linux/mfd/cros_ec_commands.h>
 #include <linux/mutex.h>
 
+#define CROS_EC_DEV_NAME "cros_ec"
+#define CROS_EC_DEV_PD_NAME "cros_pd"
+
 /*
  * The EC is unresponsive for a time after a reboot command.  Add a
  * simple delay to make sure that the bus stays locked.
@@ -71,11 +75,8 @@  struct cros_ec_command {
 /**
  * struct cros_ec_device - Information about a ChromeOS EC device
  *
- * @ec_name: name of EC device (e.g. 'chromeos-ec')
  * @phys_name: name of physical comms layer (e.g. 'i2c-4')
  * @dev: Device pointer for physical comms device
- * @vdev: Device pointer for virtual comms device
- * @cdev: Character device structure for virtual comms device
  * @was_wake_device: true if this device was set to wake the system from
  * sleep at the last suspend
  * @cmd_readmem: direct read of the EC memory-mapped region, if supported
@@ -87,6 +88,7 @@  struct cros_ec_command {
  *
  * @priv: Private data
  * @irq: Interrupt to use
+ * @id: Device id
  * @din: input buffer (for data from EC)
  * @dout: output buffer (for data to EC)
  * \note
@@ -109,11 +111,8 @@  struct cros_ec_command {
 struct cros_ec_device {
 
 	/* These are used by other drivers that want to talk to the EC */
-	const char *ec_name;
 	const char *phys_name;
 	struct device *dev;
-	struct device *vdev;
-	struct cdev cdev;
 	bool was_wake_device;
 	struct class *cros_class;
 	int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
@@ -138,6 +137,35 @@  struct cros_ec_device {
 	struct mutex lock;
 };
 
+/* struct cros_ec_platform - ChromeOS EC platform information
+ *
+ * @ec_name: name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
+ * used in /dev/ and sysfs.
+ * @cmd_offset: offset to apply for each command. Set when
+ * registering a devicde behind another one.
+ */
+struct cros_ec_platform {
+	const char *ec_name;
+	u16 cmd_offset;
+};
+
+/*
+ * struct cros_ec_dev - ChromeOS EC device entry point
+ *
+ * @class_dev: Device structure used in sysfs
+ * @cdev: Character device structure in /dev
+ * @ec_dev: cros_ec_device structure to talk to the physical device
+ * @dev: pointer to the platform device
+ * @cmd_offset: offset to apply for each command.
+ */
+struct cros_ec_dev {
+	struct device class_dev;
+	struct cdev cdev;
+	struct cros_ec_device *ec_dev;
+	struct device *dev;
+	u16 cmd_offset;
+};
+
 /**
  * cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device
  *
@@ -224,4 +252,8 @@  int cros_ec_register(struct cros_ec_device *ec_dev);
  */
 int cros_ec_query_all(struct cros_ec_device *ec_dev);
 
+/* sysfs stuff */
+extern struct attribute_group cros_ec_attr_group;
+extern struct attribute_group cros_ec_lightbar_attr_group;
+
 #endif /* __LINUX_MFD_CROS_EC_H */