Commit 7aa703bb authored by Enric Balletbo i Serra's avatar Enric Balletbo i Serra Committed by Lee Jones
Browse files

mfd / platform: cros_ec: Handle chained ECs as platform devices 



An MFD is a device that contains several sub-devices (cells). For instance,
the ChromeOS EC fits in this description as usually contains a charger and
can have other devices with different functions like a Real-Time Clock,
an Audio codec, a Real-Time Clock, ...

If you look at the driver, though, we're doing something odd. We have
two MFD cros-ec drivers where one of them (cros-ec-core) instantiates
another MFD driver as sub-driver (cros-ec-dev), and the latest
instantiates the different sub-devices (Real-Time Clock, Audio codec,
etc).

                  MFD
------------------------------------------
   cros-ec-core
       |___ mfd-cellA (cros-ec-dev)
       |       |__ mfd-cell0
       |       |__ mfd-cell1
       |       |__ ...
       |
       |___ mfd-cellB (cros-ec-dev)
               |__ mfd-cell0
               |__ mfd-cell1
               |__ ...

The problem that was trying to solve is to describe some kind of topology for
the case where we have an EC (cros-ec) chained with another EC
(cros-pd). Apart from that this extends the bounds of what MFD was
designed to do we might be interested on have other kinds of topology that
can't be implemented in that way.

Let's prepare the code to move the cros-ec-core part from MFD to
platform/chrome as this is clearly a platform specific thing non-related
to a MFD device.

  platform/chrome  |         MFD
------------------------------------------
                   |
   cros-ec ________|___ cros-ec-dev
                   |       |__ mfd-cell0
                   |       |__ mfd-cell1
                   |       |__ ...
                   |
   cros-pd ________|___ cros-ec-dev
                   |        |__ mfd-cell0
                   |        |__ mfd-cell1
                   |        |__ ...

Signed-off-by: default avatarEnric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarGwendal Grignou <gwendal@chromium.org>
Tested-by: default avatarGwendal Grignou <gwendal@chromium.org>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
parent 5f9e832c

drivers/mfd/cros_ec.c

+31 −30
Original line number Diff line number Diff line
@@ -13,7 +13,6 @@ 
#include <linux/interrupt.h>

#include <linux/slab.h>

#include <linux/module.h>

#include <linux/mfd/core.h>

#include <linux/mfd/cros_ec.h>

#include <linux/suspend.h>

#include <asm/unaligned.h>
@@ -31,18 +30,6 @@ static struct cros_ec_platform pd_p = { 
	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),

};



static const struct mfd_cell ec_cell = {

	.name = "cros-ec-dev",

	.platform_data = &ec_p,

	.pdata_size = sizeof(ec_p),

};



static const struct mfd_cell ec_pd_cell = {

	.name = "cros-ec-dev",

	.platform_data = &pd_p,

	.pdata_size = sizeof(pd_p),

};



static irqreturn_t ec_irq_thread(int irq, void *data)

{

	struct cros_ec_device *ec_dev = data;
@@ -154,38 +141,42 @@ int cros_ec_register(struct cros_ec_device *ec_dev) 
		}

	}



	err = devm_mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &ec_cell,

				   1, NULL, ec_dev->irq, NULL);

	if (err) {

		dev_err(dev,

			"Failed to register Embedded Controller subdevice %d\n",

			err);

		return err;

	/* Register a platform device for the main EC instance */

	ec_dev->ec = platform_device_register_data(ec_dev->dev, "cros-ec-dev",

					PLATFORM_DEVID_AUTO, &ec_p,

					sizeof(struct cros_ec_platform));

	if (IS_ERR(ec_dev->ec)) {

		dev_err(ec_dev->dev,

			"Failed to create CrOS EC platform device\n");

		return PTR_ERR(ec_dev->ec);

	}



	if (ec_dev->max_passthru) {

		/*

		 * Register a PD device as well on top of this device.

		 * Register a platform device for the PD behind the main EC.

		 * 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.

		 *   sensor hub).

		 */

		err = devm_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 register Power Delivery subdevice %d\n",

				err);

			return err;

		ec_dev->pd = platform_device_register_data(ec_dev->dev,

					"cros-ec-dev",

					PLATFORM_DEVID_AUTO, &pd_p,

					sizeof(struct cros_ec_platform));

		if (IS_ERR(ec_dev->pd)) {

			dev_err(ec_dev->dev,

				"Failed to create CrOS PD platform device\n");

			platform_device_unregister(ec_dev->ec);

			return PTR_ERR(ec_dev->pd);

		}

	}



	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {

		err = devm_of_platform_populate(dev);

		if (err) {

			mfd_remove_devices(dev);

			platform_device_unregister(ec_dev->pd);

			platform_device_unregister(ec_dev->ec);

			dev_err(dev, "Failed to register sub-devices\n");

			return err;

		}
@@ -206,6 +197,16 @@ int cros_ec_register(struct cros_ec_device *ec_dev) 
}

EXPORT_SYMBOL(cros_ec_register);



int cros_ec_unregister(struct cros_ec_device *ec_dev)

{

	if (ec_dev->pd)

		platform_device_unregister(ec_dev->pd);

	platform_device_unregister(ec_dev->ec);



	return 0;

}

EXPORT_SYMBOL(cros_ec_unregister);



#ifdef CONFIG_PM_SLEEP

int cros_ec_suspend(struct cros_ec_device *ec_dev)

{

drivers/platform/chrome/cros_ec_i2c.c

+8 −0
Original line number Diff line number Diff line
@@ -307,6 +307,13 @@ static int cros_ec_i2c_probe(struct i2c_client *client, 
	return 0;

}



static int cros_ec_i2c_remove(struct i2c_client *client)

{

	struct cros_ec_device *ec_dev = i2c_get_clientdata(client);



	return cros_ec_unregister(ec_dev);

}



#ifdef CONFIG_PM_SLEEP

static int cros_ec_i2c_suspend(struct device *dev)

{
@@ -357,6 +364,7 @@ static struct i2c_driver cros_ec_driver = { 
		.pm	= &cros_ec_i2c_pm_ops,

	},

	.probe		= cros_ec_i2c_probe,

	.remove		= cros_ec_i2c_remove,

	.id_table	= cros_ec_i2c_id,

};

drivers/platform/chrome/cros_ec_lpc.c

+2 −1
Original line number Diff line number Diff line
@@ -421,6 +421,7 @@ static int cros_ec_lpc_probe(struct platform_device *pdev) 


static int cros_ec_lpc_remove(struct platform_device *pdev)

{

	struct cros_ec_device *ec_dev = platform_get_drvdata(pdev);

	struct acpi_device *adev;



	adev = ACPI_COMPANION(&pdev->dev);
@@ -428,7 +429,7 @@ static int cros_ec_lpc_remove(struct platform_device *pdev) 
		acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY,

					   cros_ec_lpc_acpi_notify);



	return 0;

	return cros_ec_unregister(ec_dev);

}



static const struct acpi_device_id cros_ec_lpc_acpi_device_ids[] = {

drivers/platform/chrome/cros_ec_rpmsg.c

+2 −0
Original line number Diff line number Diff line
@@ -233,6 +233,8 @@ static void cros_ec_rpmsg_remove(struct rpmsg_device *rpdev) 
	struct cros_ec_device *ec_dev = dev_get_drvdata(&rpdev->dev);

	struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;



	cros_ec_unregister(ec_dev);



	cancel_work_sync(&ec_rpmsg->host_event_work);

}

drivers/platform/chrome/cros_ec_spi.c

+8 −0
Original line number Diff line number Diff line
@@ -785,6 +785,13 @@ static int cros_ec_spi_probe(struct spi_device *spi) 
	return 0;

}



static int cros_ec_spi_remove(struct spi_device *spi)

{

	struct cros_ec_device *ec_dev = spi_get_drvdata(spi);



	return cros_ec_unregister(ec_dev);

}



#ifdef CONFIG_PM_SLEEP

static int cros_ec_spi_suspend(struct device *dev)

{
@@ -823,6 +830,7 @@ static struct spi_driver cros_ec_driver_spi = { 
		.pm	= &cros_ec_spi_pm_ops,

	},

	.probe		= cros_ec_spi_probe,

	.remove		= cros_ec_spi_remove,

	.id_table	= cros_ec_spi_id,

};

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