| Message ID | 20230630110643.209761-15-hdegoede@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | media: ipu-bridge: Shared with atomisp, rework VCM instantiation | expand |
Hi Hans On 30/06/2023 13:06, Hans de Goede wrote: > In most cases when a VCM is used there is a single integrated module > with the sensor + VCM + lens. This means that the sensor and VCM often > share regulators and possibly also something like a powerdown pin. > > In the ACPI tables this is modelled as a single ACPI device with > multiple I2cSerialBus resources. > > On atomisp devices the regulators and clks are modelled as ACPI > power-resources, which are controlled by the (ACPI) power state > of the sensor. So the sensor must be in D0 power state for the VCM > to work. > > To make this work add a device-link with DL_FLAG_PM_RUNTIME flag > so that the sensor will automatically be runtime-resumed whenever > the VCM is runtime-resumed. > > This requires the probing of the VCM and thus the creation of the VCM > I2C-client to be delayed till after the sensor driver has bound. > > Move the instantiation of the VCM I2C-client to the v4l2_async_notifier > bound op, so that it is done after the sensor driver has bound; and > add code to add the device-link. > > This fixes the problem with the shared ACPI power-resources on atomisp2 > and this avoids the need for VCM related workarounds on IPU3 / IPU6. > > E.g. until now the dw9719 driver needed to get and control a Vsio > (V sensor IO) regulator since that needs to be enabled to enable I2C > pass-through on the PMIC on the sensor module. So the driver was > controlling this regulator even though the actual dw9719 chip has no > Vsio pin / power-plane. > > This also removes the need for ipu_bridge_init() to return > -EPROBE_DEFER since the VCM is now instantiated later. > > Reviewed-by: Andy Shevchenko <andy@kernel.org> > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- This is a really cool way of solving the problem I think; Sakari mentioned it to me a little while ago, it's nice to see the implementation, thanks for doing it. Just one comment below for ipu_bridge_instantiate_vcm(), but: Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com> I also tested the set on my Go and as far as I can tell everything works fine. Not really applicable to 13/15 since that's atomisp specific but otherwise: Tested-by: Daniel Scally <dan.scally@ideasonboard.com> > drivers/media/pci/intel/ipu-bridge.c | 159 +++++++++++++++-------- > drivers/media/pci/intel/ipu3/ipu3-cio2.c | 5 + > include/media/ipu-bridge.h | 5 +- > 3 files changed, 109 insertions(+), 60 deletions(-) > > diff --git a/drivers/media/pci/intel/ipu-bridge.c b/drivers/media/pci/intel/ipu-bridge.c > index 07a34f20af8e..32dabc16a7b4 100644 > --- a/drivers/media/pci/intel/ipu-bridge.c > +++ b/drivers/media/pci/intel/ipu-bridge.c > @@ -4,7 +4,9 @@ > #include <linux/acpi.h> > #include <linux/device.h> > #include <linux/i2c.h> > +#include <linux/pm_runtime.h> > #include <linux/property.h> > +#include <linux/workqueue.h> > > #include <media/ipu-bridge.h> > #include <media/v4l2-fwnode.h> > @@ -289,29 +291,112 @@ static void ipu_bridge_create_connection_swnodes(struct ipu_bridge *bridge, > ipu_bridge_init_swnode_group(sensor); > } > > -static void ipu_bridge_instantiate_vcm_i2c_client(struct ipu_sensor *sensor) > -{ > - struct i2c_board_info board_info = { }; > +/* > + * The actual instantiation must be done from a workqueue to avoid > + * a deadlock on taking list_lock from v4l2-async twice. > + */ > +struct ipu_bridge_instantiate_vcm_work_data { > + struct work_struct work; > + struct device *sensor; > char name[16]; > + struct i2c_board_info board_info; > +}; > > - if (!sensor->vcm_type) > - return; > +static void ipu_bridge_instantiate_vcm_work(struct work_struct *_work) > +{ > + struct ipu_bridge_instantiate_vcm_work_data *work = > + container_of(_work, > + struct ipu_bridge_instantiate_vcm_work_data, > + work); > + struct acpi_device *adev = ACPI_COMPANION(work->sensor); > + struct i2c_client *vcm_client; > + bool put_fwnode = true; > + int ret; > > - snprintf(name, sizeof(name), "%s-VCM", acpi_dev_name(sensor->adev)); > - board_info.dev_name = name; > - strscpy(board_info.type, sensor->vcm_type, ARRAY_SIZE(board_info.type)); > - board_info.swnode = &sensor->swnodes[SWNODE_VCM]; > - > - sensor->vcm_i2c_client = > - i2c_acpi_new_device_by_fwnode(acpi_fwnode_handle(sensor->adev), > - 1, &board_info); > - if (IS_ERR(sensor->vcm_i2c_client)) { > - dev_warn(&sensor->adev->dev, "Error instantiation VCM i2c-client: %ld\n", > - PTR_ERR(sensor->vcm_i2c_client)); > - sensor->vcm_i2c_client = NULL; > + /* > + * The client may get probed before the device_link gets added below > + * make sure the sensor is powered-up during probe. > + */ > + ret = pm_runtime_get_sync(work->sensor); > + if (ret < 0) { > + dev_err(work->sensor, "Error %d runtime-resuming sensor, cannot instantiate VCM\n", > + ret); > + goto out; > } > + > + /* > + * Note the client is created only once and then kept around > + * even after a rmmod, just like the software-nodes. > + */ > + vcm_client = i2c_acpi_new_device_by_fwnode(acpi_fwnode_handle(adev), > + 1, &work->board_info); > + if (IS_ERR(vcm_client)) { > + dev_err(work->sensor, "Error instantiating VCM client: %ld\n", > + PTR_ERR(vcm_client)); > + goto out; > + } > + > + device_link_add(&vcm_client->dev, work->sensor, DL_FLAG_PM_RUNTIME); > + > + dev_info(work->sensor, "Instantiated %s VCM\n", work->board_info.type); > + put_fwnode = false; /* Ownership has passed to the i2c-client */ > + > +out: > + pm_runtime_put(work->sensor); > + put_device(work->sensor); > + if (put_fwnode) > + fwnode_handle_put(work->board_info.fwnode); > + kfree(work); > } > > +int ipu_bridge_instantiate_vcm(struct device *sensor) > +{ > + struct ipu_bridge_instantiate_vcm_work_data *work; > + struct fwnode_handle *vcm_fwnode; > + struct i2c_client *vcm_client; > + struct acpi_device *adev; > + char *sep; > + > + adev = ACPI_COMPANION(sensor); > + if (!adev) > + return 0; > + > + vcm_fwnode = fwnode_find_reference(dev_fwnode(sensor), "lens-focus", 0); > + if (IS_ERR(vcm_fwnode)) > + return 0; > + > + /* When reloading modules the client will already exist */ > + vcm_client = i2c_find_device_by_fwnode(vcm_fwnode); > + if (vcm_client) { > + fwnode_handle_put(vcm_fwnode); > + put_device(&vcm_client->dev); > + return 0; > + } > + > + work = kzalloc(sizeof(*work), GFP_KERNEL); > + if (!work) { > + fwnode_handle_put(vcm_fwnode); > + return -ENOMEM; > + } > + > + INIT_WORK(&work->work, ipu_bridge_instantiate_vcm_work); > + work->sensor = get_device(sensor); > + snprintf(work->name, sizeof(work->name), "%s-VCM", > + acpi_dev_name(adev)); > + work->board_info.dev_name = work->name; > + work->board_info.fwnode = vcm_fwnode; > + strscpy(work->board_info.type, fwnode_get_name(vcm_fwnode), > + I2C_NAME_SIZE); > + /* Strip "-<link>" postfix */ > + sep = strchrnul(work->board_info.type, '-'); > + *sep = 0; I think strreplace(work->board_info.type, '-', '\0') here would be cleaner, and either way probably we need #include <linux/string.h> for the str* funcs here > + > + queue_work(system_long_wq, &work->work); > + > + return 0; > +} > +EXPORT_SYMBOL(ipu_bridge_instantiate_vcm); > + > static void ipu_bridge_unregister_sensors(struct ipu_bridge *bridge) > { > struct ipu_sensor *sensor; > @@ -321,7 +406,6 @@ static void ipu_bridge_unregister_sensors(struct ipu_bridge *bridge) > sensor = &bridge->sensors[i]; > software_node_unregister_node_group(sensor->group); > acpi_dev_put(sensor->adev); > - i2c_unregister_device(sensor->vcm_i2c_client); > } > } > > @@ -371,8 +455,6 @@ static int ipu_bridge_connect_sensor(const struct ipu_sensor_config *cfg, > primary = acpi_fwnode_handle(adev); > primary->secondary = fwnode; > > - ipu_bridge_instantiate_vcm_i2c_client(sensor); > - > dev_info(bridge->dev, "Found supported sensor %s\n", > acpi_dev_name(adev)); > > @@ -409,40 +491,6 @@ static int ipu_bridge_connect_sensors(struct ipu_bridge *bridge) > return ret; > } > > -/* > - * The VCM cannot be probed until the PMIC is completely setup. We cannot rely > - * on -EPROBE_DEFER for this, since the consumer<->supplier relations between > - * the VCM and regulators/clks are not described in ACPI, instead they are > - * passed as board-data to the PMIC drivers. Since -PROBE_DEFER does not work > - * for the clks/regulators the VCM i2c-clients must not be instantiated until > - * the PMIC is fully setup. > - * > - * The sensor/VCM ACPI device has an ACPI _DEP on the PMIC, check this using the > - * acpi_dev_ready_for_enumeration() helper, like the i2c-core-acpi code does > - * for the sensors. > - */ > -static int ipu_bridge_sensors_are_ready(void) > -{ > - struct acpi_device *adev; > - bool ready = true; > - unsigned int i; > - > - for (i = 0; i < ARRAY_SIZE(ipu_supported_sensors); i++) { > - const struct ipu_sensor_config *cfg = > - &ipu_supported_sensors[i]; > - > - for_each_acpi_dev_match(adev, cfg->hid, NULL, -1) { > - if (!adev->status.enabled) > - continue; > - > - if (!acpi_dev_ready_for_enumeration(adev)) > - ready = false; > - } > - } > - > - return ready; > -} > - > int ipu_bridge_init(struct device *dev, > int (*parse_sensor_fwnode)(struct acpi_device *adev, > struct ipu_sensor *sensor)) > @@ -452,9 +500,6 @@ int ipu_bridge_init(struct device *dev, > unsigned int i; > int ret; > > - if (!ipu_bridge_sensors_are_ready()) > - return -EPROBE_DEFER; > - > bridge = kzalloc(sizeof(*bridge), GFP_KERNEL); > if (!bridge) > return -ENOMEM; > diff --git a/drivers/media/pci/intel/ipu3/ipu3-cio2.c b/drivers/media/pci/intel/ipu3/ipu3-cio2.c > index 51a6d7cc44d2..690fc1c919af 100644 > --- a/drivers/media/pci/intel/ipu3/ipu3-cio2.c > +++ b/drivers/media/pci/intel/ipu3/ipu3-cio2.c > @@ -1388,10 +1388,15 @@ static int cio2_notifier_bound(struct v4l2_async_notifier *notifier, > struct cio2_device *cio2 = to_cio2_device(notifier); > struct sensor_async_subdev *s_asd = to_sensor_asd(asd); > struct cio2_queue *q; > + int ret; > > if (cio2->queue[s_asd->csi2.port].sensor) > return -EBUSY; > > + ret = ipu_bridge_instantiate_vcm(sd->dev); > + if (ret) > + return ret; > + > q = &cio2->queue[s_asd->csi2.port]; > > q->csi2 = s_asd->csi2; > diff --git a/include/media/ipu-bridge.h b/include/media/ipu-bridge.h > index 969d8d7d6b93..31b138170c73 100644 > --- a/include/media/ipu-bridge.h > +++ b/include/media/ipu-bridge.h > @@ -7,8 +7,6 @@ > #include <linux/types.h> > #include <media/v4l2-fwnode.h> > > -struct i2c_client; > - > #define IPU_HID "INT343E" > #define IPU_MAX_LANES 4 > #define IPU_MAX_PORTS 4 > @@ -117,7 +115,6 @@ struct ipu_sensor { > /* append ssdb.link(u8) in "-%u" format as suffix of HID */ > char name[ACPI_ID_LEN + 4]; > struct acpi_device *adev; > - struct i2c_client *vcm_i2c_client; > > /* SWNODE_COUNT + 1 for terminating NULL */ > const struct software_node *group[SWNODE_COUNT + 1]; > @@ -156,9 +153,11 @@ int ipu_bridge_init(struct device *dev, > int (*parse_sensor_fwnode)(struct acpi_device *adev, > struct ipu_sensor *sensor)); > int ipu_bridge_parse_ssdb(struct acpi_device *adev, struct ipu_sensor *sensor); > +int ipu_bridge_instantiate_vcm(struct device *sensor); > #else > /* Use a define to avoid the parse_sensor_fwnode arg getting evaluated */ > #define ipu_bridge_init(dev, parse_sensor_fwnode) (0) > +static inline int ipu_bridge_instantiate_vcm(struct device *s) { return 0; } > #endif > > #endif
On Tue, Jul 04, 2023 at 04:07:43PM +0100, Dan Scally wrote: > On 30/06/2023 13:06, Hans de Goede wrote: ... > > + strscpy(work->board_info.type, fwnode_get_name(vcm_fwnode), > > + I2C_NAME_SIZE); > > + /* Strip "-<link>" postfix */ > > + sep = strchrnul(work->board_info.type, '-'); > > + *sep = 0; > > I think strreplace(work->board_info.type, '-', '\0') here would be cleaner, > and either way probably we need #include <linux/string.h> for the str* funcs > here What we need is something like strcut(str, '<$CHAR>'). But related to the above code we can (besides using sizeof() instead of I2C_NAME_SIZE): snprintf(work->board_info.type, sizeof(work->board_info.type), "%pfwP", vcm_fwnode);
Hi, On 7/4/23 17:27, Andy Shevchenko wrote: > On Tue, Jul 04, 2023 at 04:07:43PM +0100, Dan Scally wrote: >> On 30/06/2023 13:06, Hans de Goede wrote: > > ... > >>> + strscpy(work->board_info.type, fwnode_get_name(vcm_fwnode), >>> + I2C_NAME_SIZE); >>> + /* Strip "-<link>" postfix */ >>> + sep = strchrnul(work->board_info.type, '-'); >>> + *sep = 0; >> >> I think strreplace(work->board_info.type, '-', '\0') here would be cleaner, >> and either way probably we need #include <linux/string.h> for the str* funcs >> here > > What we need is something like strcut(str, '<$CHAR>'). > > But related to the above code we can (besides using sizeof() instead > of I2C_NAME_SIZE): > > snprintf(work->board_info.type, sizeof(work->board_info.type), > "%pfwP", vcm_fwnode); "%pfwP" ? what on earth does that do ? Regards, Hans
diff --git a/drivers/media/pci/intel/ipu-bridge.c b/drivers/media/pci/intel/ipu-bridge.c index 07a34f20af8e..32dabc16a7b4 100644 --- a/drivers/media/pci/intel/ipu-bridge.c +++ b/drivers/media/pci/intel/ipu-bridge.c @@ -4,7 +4,9 @@ #include <linux/acpi.h> #include <linux/device.h> #include <linux/i2c.h> +#include <linux/pm_runtime.h> #include <linux/property.h> +#include <linux/workqueue.h> #include <media/ipu-bridge.h> #include <media/v4l2-fwnode.h> @@ -289,29 +291,112 @@ static void ipu_bridge_create_connection_swnodes(struct ipu_bridge *bridge, ipu_bridge_init_swnode_group(sensor); } -static void ipu_bridge_instantiate_vcm_i2c_client(struct ipu_sensor *sensor) -{ - struct i2c_board_info board_info = { }; +/* + * The actual instantiation must be done from a workqueue to avoid + * a deadlock on taking list_lock from v4l2-async twice. + */ +struct ipu_bridge_instantiate_vcm_work_data { + struct work_struct work; + struct device *sensor; char name[16]; + struct i2c_board_info board_info; +}; - if (!sensor->vcm_type) - return; +static void ipu_bridge_instantiate_vcm_work(struct work_struct *_work) +{ + struct ipu_bridge_instantiate_vcm_work_data *work = + container_of(_work, + struct ipu_bridge_instantiate_vcm_work_data, + work); + struct acpi_device *adev = ACPI_COMPANION(work->sensor); + struct i2c_client *vcm_client; + bool put_fwnode = true; + int ret; - snprintf(name, sizeof(name), "%s-VCM", acpi_dev_name(sensor->adev)); - board_info.dev_name = name; - strscpy(board_info.type, sensor->vcm_type, ARRAY_SIZE(board_info.type)); - board_info.swnode = &sensor->swnodes[SWNODE_VCM]; - - sensor->vcm_i2c_client = - i2c_acpi_new_device_by_fwnode(acpi_fwnode_handle(sensor->adev), - 1, &board_info); - if (IS_ERR(sensor->vcm_i2c_client)) { - dev_warn(&sensor->adev->dev, "Error instantiation VCM i2c-client: %ld\n", - PTR_ERR(sensor->vcm_i2c_client)); - sensor->vcm_i2c_client = NULL; + /* + * The client may get probed before the device_link gets added below + * make sure the sensor is powered-up during probe. + */ + ret = pm_runtime_get_sync(work->sensor); + if (ret < 0) { + dev_err(work->sensor, "Error %d runtime-resuming sensor, cannot instantiate VCM\n", + ret); + goto out; } + + /* + * Note the client is created only once and then kept around + * even after a rmmod, just like the software-nodes. + */ + vcm_client = i2c_acpi_new_device_by_fwnode(acpi_fwnode_handle(adev), + 1, &work->board_info); + if (IS_ERR(vcm_client)) { + dev_err(work->sensor, "Error instantiating VCM client: %ld\n", + PTR_ERR(vcm_client)); + goto out; + } + + device_link_add(&vcm_client->dev, work->sensor, DL_FLAG_PM_RUNTIME); + + dev_info(work->sensor, "Instantiated %s VCM\n", work->board_info.type); + put_fwnode = false; /* Ownership has passed to the i2c-client */ + +out: + pm_runtime_put(work->sensor); + put_device(work->sensor); + if (put_fwnode) + fwnode_handle_put(work->board_info.fwnode); + kfree(work); } +int ipu_bridge_instantiate_vcm(struct device *sensor) +{ + struct ipu_bridge_instantiate_vcm_work_data *work; + struct fwnode_handle *vcm_fwnode; + struct i2c_client *vcm_client; + struct acpi_device *adev; + char *sep; + + adev = ACPI_COMPANION(sensor); + if (!adev) + return 0; + + vcm_fwnode = fwnode_find_reference(dev_fwnode(sensor), "lens-focus", 0); + if (IS_ERR(vcm_fwnode)) + return 0; + + /* When reloading modules the client will already exist */ + vcm_client = i2c_find_device_by_fwnode(vcm_fwnode); + if (vcm_client) { + fwnode_handle_put(vcm_fwnode); + put_device(&vcm_client->dev); + return 0; + } + + work = kzalloc(sizeof(*work), GFP_KERNEL); + if (!work) { + fwnode_handle_put(vcm_fwnode); + return -ENOMEM; + } + + INIT_WORK(&work->work, ipu_bridge_instantiate_vcm_work); + work->sensor = get_device(sensor); + snprintf(work->name, sizeof(work->name), "%s-VCM", + acpi_dev_name(adev)); + work->board_info.dev_name = work->name; + work->board_info.fwnode = vcm_fwnode; + strscpy(work->board_info.type, fwnode_get_name(vcm_fwnode), + I2C_NAME_SIZE); + /* Strip "-<link>" postfix */ + sep = strchrnul(work->board_info.type, '-'); + *sep = 0; + + queue_work(system_long_wq, &work->work); + + return 0; +} +EXPORT_SYMBOL(ipu_bridge_instantiate_vcm); + static void ipu_bridge_unregister_sensors(struct ipu_bridge *bridge) { struct ipu_sensor *sensor; @@ -321,7 +406,6 @@ static void ipu_bridge_unregister_sensors(struct ipu_bridge *bridge) sensor = &bridge->sensors[i]; software_node_unregister_node_group(sensor->group); acpi_dev_put(sensor->adev); - i2c_unregister_device(sensor->vcm_i2c_client); } } @@ -371,8 +455,6 @@ static int ipu_bridge_connect_sensor(const struct ipu_sensor_config *cfg, primary = acpi_fwnode_handle(adev); primary->secondary = fwnode; - ipu_bridge_instantiate_vcm_i2c_client(sensor); - dev_info(bridge->dev, "Found supported sensor %s\n", acpi_dev_name(adev)); @@ -409,40 +491,6 @@ static int ipu_bridge_connect_sensors(struct ipu_bridge *bridge) return ret; } -/* - * The VCM cannot be probed until the PMIC is completely setup. We cannot rely - * on -EPROBE_DEFER for this, since the consumer<->supplier relations between - * the VCM and regulators/clks are not described in ACPI, instead they are - * passed as board-data to the PMIC drivers. Since -PROBE_DEFER does not work - * for the clks/regulators the VCM i2c-clients must not be instantiated until - * the PMIC is fully setup. - * - * The sensor/VCM ACPI device has an ACPI _DEP on the PMIC, check this using the - * acpi_dev_ready_for_enumeration() helper, like the i2c-core-acpi code does - * for the sensors. - */ -static int ipu_bridge_sensors_are_ready(void) -{ - struct acpi_device *adev; - bool ready = true; - unsigned int i; - - for (i = 0; i < ARRAY_SIZE(ipu_supported_sensors); i++) { - const struct ipu_sensor_config *cfg = - &ipu_supported_sensors[i]; - - for_each_acpi_dev_match(adev, cfg->hid, NULL, -1) { - if (!adev->status.enabled) - continue; - - if (!acpi_dev_ready_for_enumeration(adev)) - ready = false; - } - } - - return ready; -} - int ipu_bridge_init(struct device *dev, int (*parse_sensor_fwnode)(struct acpi_device *adev, struct ipu_sensor *sensor)) @@ -452,9 +500,6 @@ int ipu_bridge_init(struct device *dev, unsigned int i; int ret; - if (!ipu_bridge_sensors_are_ready()) - return -EPROBE_DEFER; - bridge = kzalloc(sizeof(*bridge), GFP_KERNEL); if (!bridge) return -ENOMEM; diff --git a/drivers/media/pci/intel/ipu3/ipu3-cio2.c b/drivers/media/pci/intel/ipu3/ipu3-cio2.c index 51a6d7cc44d2..690fc1c919af 100644 --- a/drivers/media/pci/intel/ipu3/ipu3-cio2.c +++ b/drivers/media/pci/intel/ipu3/ipu3-cio2.c @@ -1388,10 +1388,15 @@ static int cio2_notifier_bound(struct v4l2_async_notifier *notifier, struct cio2_device *cio2 = to_cio2_device(notifier); struct sensor_async_subdev *s_asd = to_sensor_asd(asd); struct cio2_queue *q; + int ret; if (cio2->queue[s_asd->csi2.port].sensor) return -EBUSY; + ret = ipu_bridge_instantiate_vcm(sd->dev); + if (ret) + return ret; + q = &cio2->queue[s_asd->csi2.port]; q->csi2 = s_asd->csi2; diff --git a/include/media/ipu-bridge.h b/include/media/ipu-bridge.h index 969d8d7d6b93..31b138170c73 100644 --- a/include/media/ipu-bridge.h +++ b/include/media/ipu-bridge.h @@ -7,8 +7,6 @@ #include <linux/types.h> #include <media/v4l2-fwnode.h> -struct i2c_client; - #define IPU_HID "INT343E" #define IPU_MAX_LANES 4 #define IPU_MAX_PORTS 4 @@ -117,7 +115,6 @@ struct ipu_sensor { /* append ssdb.link(u8) in "-%u" format as suffix of HID */ char name[ACPI_ID_LEN + 4]; struct acpi_device *adev; - struct i2c_client *vcm_i2c_client; /* SWNODE_COUNT + 1 for terminating NULL */ const struct software_node *group[SWNODE_COUNT + 1]; @@ -156,9 +153,11 @@ int ipu_bridge_init(struct device *dev, int (*parse_sensor_fwnode)(struct acpi_device *adev, struct ipu_sensor *sensor)); int ipu_bridge_parse_ssdb(struct acpi_device *adev, struct ipu_sensor *sensor); +int ipu_bridge_instantiate_vcm(struct device *sensor); #else /* Use a define to avoid the parse_sensor_fwnode arg getting evaluated */ #define ipu_bridge_init(dev, parse_sensor_fwnode) (0) +static inline int ipu_bridge_instantiate_vcm(struct device *s) { return 0; } #endif #endif