diff mbox

[v5,7/9] mfd: cros_ec: Support multiple EC in a system

Message ID 1433336644-20532-8-git-send-email-javier.martinez@collabora.co.uk (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Javier Martinez Canillas June 3, 2015, 1:04 p.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 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>
Tested-by: Heiko Stuebner <heiko@sntech.de>
---

Changes since v4:
 - Use cros-ec-name DT property instead of devname. Suggested by Lee Jones.
 - Pass PLATFORM_DEVID_AUTO directly to mfd_add_devices().
   Suggested by Lee Jones.
 - Add Heiko Stuebner tested-by tag.
 - Fix get_version by passing the cmd_offset to EC_CMD_GET_VERSION.

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.

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                      |  57 +++++++++++--
 drivers/mfd/cros_ec_i2c.c                  |   1 -
 drivers/mfd/cros_ec_spi.c                  |   1 -
 drivers/platform/chrome/cros_ec_dev.c      | 130 ++++++++++++++++++++---------
 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, 239 insertions(+), 127 deletions(-)

Comments

Lee Jones June 3, 2015, 1:49 p.m. UTC | #1
On Wed, 03 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 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>
> Tested-by: Heiko Stuebner <heiko@sntech.de>
> ---
> 
> Changes since v4:
>  - Use cros-ec-name DT property instead of devname. Suggested by Lee Jones.
>  - Pass PLATFORM_DEVID_AUTO directly to mfd_add_devices().
>    Suggested by Lee Jones.
>  - Add Heiko Stuebner tested-by tag.
>  - Fix get_version by passing the cmd_offset to EC_CMD_GET_VERSION.
> 
> 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.
> 
> 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                      |  57 +++++++++++--
>  drivers/mfd/cros_ec_i2c.c                  |   1 -
>  drivers/mfd/cros_ec_spi.c                  |   1 -
>  drivers/platform/chrome/cros_ec_dev.c      | 130 ++++++++++++++++++++---------
>  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, 239 insertions(+), 127 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..6935f385992e 100644
> --- a/drivers/mfd/cros_ec.c
> +++ b/drivers/mfd/cros_ec.c
> @@ -24,11 +24,27 @@
>  #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",
> +	.platform_data = &ec_p,
> +	.pdata_size = sizeof(ec_p),
> +};
> +
> +struct mfd_cell ec_pd_cell = {
> +	.name = "cros-ec-ctl",
> +	.platform_data = &pd_p,
> +	.pdata_size = sizeof(pd_p),
>  };
>  
>  int cros_ec_register(struct cros_ec_device *ec_dev)
> @@ -52,14 +68,39 @@ 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,
> +					       "google,cros-ec-name", NULL);

NACK

You either need to obtain this another way, or have a chat with the DT
Maintainers and explain why this platform is special enough to break
the normal conventions.

HINT: I different compatible string is normally more amenable, but
this will also require a DT ACK for me to take it through.

> +	if (!ec_p.ec_name)
> +		ec_p.ec_name = CROS_EC_DEV_NAME;
> +
> +	err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &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");

Might be nice to expand 'ec' so your users have half a chance in
deciphering what just went wrong.

[...]
Javier Martinez Canillas June 3, 2015, 2:08 p.m. UTC | #2
Hello Lee,

On 06/03/2015 03:49 PM, Lee Jones wrote:

[...]

>>  
>>  int cros_ec_register(struct cros_ec_device *ec_dev)
>> @@ -52,14 +68,39 @@ 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,
>> +					       "google,cros-ec-name", NULL);
> 
> NACK
> 
> You either need to obtain this another way, or have a chat with the DT
> Maintainers and explain why this platform is special enough to break
> the normal conventions.
> 
> HINT: I different compatible string is normally more amenable, but
> this will also require a DT ACK for me to take it through.
>

Ok, I'll just remove the property then. After all the driver only supports
two types of controllers currently, the normal host EC and the Power Delivery
(PD) one. And there isn't a DTS even in the downstream ChromiumOS tree that
is setting a different EC name right now.

I guess the idea of the binding was to make it future proof from when the
driver supports more types of controllers but I'll let Gwendal to comment on
this since he is the author of these patches.

>> +	if (!ec_p.ec_name)
>> +		ec_p.ec_name = CROS_EC_DEV_NAME;
>> +
>> +	err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &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");
> 
> Might be nice to expand 'ec' so your users have half a chance in
> deciphering what just went wrong.
>

I will, thanks a lot for your feedback.
 
> [...]
> 

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..6935f385992e 100644
--- a/drivers/mfd/cros_ec.c
+++ b/drivers/mfd/cros_ec.c
@@ -24,11 +24,27 @@ 
 #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",
+	.platform_data = &ec_p,
+	.pdata_size = sizeof(ec_p),
+};
+
+struct mfd_cell ec_pd_cell = {
+	.name = "cros-ec-ctl",
+	.platform_data = &pd_p,
+	.pdata_size = sizeof(pd_p),
 };
 
 int cros_ec_register(struct cros_ec_device *ec_dev)
@@ -52,14 +68,39 @@  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,
+					       "google,cros-ec-name", NULL);
+
+	if (!ec_p.ec_name)
+		ec_p.ec_name = CROS_EC_DEV_NAME;
+
+	err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &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, PLATFORM_DEVID_AUTO,
+				      &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..2f4099820480 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[] = {
@@ -45,11 +56,11 @@  static int ec_get_version(struct cros_ec_device *ec, char *str, int maxlen)
 		return -ENOMEM;
 
 	msg->version = 0;
-	msg->command = EC_CMD_GET_VERSION;
+	msg->command = EC_CMD_GET_VERSION + 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;
 
@@ -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 */