Commit 53c76263 authored by Frédéric Danis's avatar Frédéric Danis Committed by Greg Kroah-Hartman
Browse files

serdev: Add ACPI support 



This patch allows SerDev module to manage serial devices declared as
attached to an UART in ACPI table.

acpi_serdev_add_device() callback will only take into account entries
without enumerated flag set. This flags is set for all entries during
ACPI scan, except for SPI and I2C serial devices, and for UART with
2nd patch in the series.

Check if a serdev device as been allocated during acpi_walk_namespace()
to prevent serdev controller registration instead of the tty-class device.

Signed-off-by: default avatarFrédéric Danis <frederic.danis.oss@gmail.com>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Reviewed-by: default avatarSebastian Reichel <sebastian.reichel@collabora.co.uk>
Reviewed-by: default avatarJohan Hovold <johan@kernel.org>
Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 53501e02

drivers/tty/serdev/core.c

+95 −5
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
 * GNU General Public License for more details.

 */



#include <linux/acpi.h>

#include <linux/errno.h>

#include <linux/idr.h>

#include <linux/kernel.h>
@@ -49,13 +50,22 @@ static const struct device_type serdev_ctrl_type = { 


static int serdev_device_match(struct device *dev, struct device_driver *drv)

{

	/* TODO: ACPI and platform matching */

	/* TODO: platform matching */

	if (acpi_driver_match_device(dev, drv))

		return 1;



	return of_driver_match_device(dev, drv);

}



static int serdev_uevent(struct device *dev, struct kobj_uevent_env *env)

{

	/* TODO: ACPI and platform modalias */

	int rc;



	/* TODO: platform modalias */

	rc = acpi_device_uevent_modalias(dev, env);

	if (rc != -ENODEV)

		return rc;



	return of_device_uevent_modalias(dev, env);

}
@@ -260,6 +270,12 @@ static int serdev_drv_remove(struct device *dev) 
static ssize_t modalias_show(struct device *dev,

			     struct device_attribute *attr, char *buf)

{

	int len;



	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);

	if (len != -ENODEV)

		return len;



	return of_device_modalias(dev, buf, PAGE_SIZE);

}

DEVICE_ATTR_RO(modalias);
@@ -385,6 +401,75 @@ static int of_serdev_register_devices(struct serdev_controller *ctrl) 
	return 0;

}



#ifdef CONFIG_ACPI

static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl,

					    struct acpi_device *adev)

{

	struct serdev_device *serdev = NULL;

	int err;



	if (acpi_bus_get_status(adev) || !adev->status.present ||

	    acpi_device_enumerated(adev))

		return AE_OK;



	serdev = serdev_device_alloc(ctrl);

	if (!serdev) {

		dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n",

			dev_name(&adev->dev));

		return AE_NO_MEMORY;

	}



	ACPI_COMPANION_SET(&serdev->dev, adev);

	acpi_device_set_enumerated(adev);



	err = serdev_device_add(serdev);

	if (err) {

		dev_err(&serdev->dev,

			"failure adding ACPI serdev device. status %d\n", err);

		serdev_device_put(serdev);

	}



	return AE_OK;

}



static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level,

				       void *data, void **return_value)

{

	struct serdev_controller *ctrl = data;

	struct acpi_device *adev;



	if (acpi_bus_get_device(handle, &adev))

		return AE_OK;



	return acpi_serdev_register_device(ctrl, adev);

}



static int acpi_serdev_register_devices(struct serdev_controller *ctrl)

{

	acpi_status status;

	acpi_handle handle;



	handle = ACPI_HANDLE(ctrl->dev.parent);

	if (!handle)

		return -ENODEV;



	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,

				     acpi_serdev_add_device, NULL, ctrl, NULL);

	if (ACPI_FAILURE(status))

		dev_dbg(&ctrl->dev, "failed to enumerate serdev slaves\n");



	if (!ctrl->serdev)

		return -ENODEV;



	return 0;

}

#else

static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl)

{

	return -ENODEV;

}

#endif /* CONFIG_ACPI */



/**

 * serdev_controller_add() - Add an serdev controller

 * @ctrl:	controller to be registered.
@@ -394,7 +479,7 @@ static int of_serdev_register_devices(struct serdev_controller *ctrl) 
 */

int serdev_controller_add(struct serdev_controller *ctrl)

{

	int ret;

	int ret_of, ret_acpi, ret;



	/* Can't register until after driver model init */

	if (WARN_ON(!is_registered))
@@ -404,9 +489,14 @@ int serdev_controller_add(struct serdev_controller *ctrl) 
	if (ret)

		return ret;



	ret = of_serdev_register_devices(ctrl);

	if (ret)

	ret_of = of_serdev_register_devices(ctrl);

	ret_acpi = acpi_serdev_register_devices(ctrl);

	if (ret_of && ret_acpi) {

		dev_dbg(&ctrl->dev, "no devices registered: of:%d acpi:%d\n",

			ret_of, ret_acpi);

		ret = -ENODEV;

		goto out_dev_del;

	}



	dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",

		ctrl->nr, &ctrl->dev);

CRA Git | Maintained and supported by SUSTech CRA and CCSE