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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-04-29 11:18:34 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-04-29 11:18:34 -0700 |
commit | 4f567cbc957a7cffd1a428a000d93bd903f42349 (patch) | |
tree | e648bfed3732a23031a32811b20975827dad62d2 /Documentation | |
parent | 92ddcf4a011a95dac98d3bbb0211a2fa42f13dc1 (diff) | |
parent | 0e27263926699fcbbd574cff4dd6920007a50e8a (diff) | |
download | lwn-4f567cbc957a7cffd1a428a000d93bd903f42349.tar.gz lwn-4f567cbc957a7cffd1a428a000d93bd903f42349.zip |
Merge tag 'char-misc-3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver update from Greg Kroah-Hartman:
"Here's the big char / misc driver update for 3.10-rc1
A number of various driver updates, the majority being new
functionality in the MEI driver subsystem (it's now a subsystem, it
started out just a single driver), extcon updates, memory updates,
hyper-v updates, and a bunch of other small stuff that doesn't fit in
any other tree.
All of these have been in linux-next for a while"
* tag 'char-misc-3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (148 commits)
Tools: hv: Fix a checkpatch warning
tools: hv: skip iso9660 mounts in hv_vss_daemon
tools: hv: use FIFREEZE/FITHAW in hv_vss_daemon
tools: hv: use getmntent in hv_vss_daemon
Tools: hv: Fix a checkpatch warning
tools: hv: fix checks for origin of netlink message in hv_vss_daemon
Tools: hv: fix warnings in hv_vss_daemon
misc: mark spear13xx-pcie-gadget as broken
mei: fix krealloc() misuse in in mei_cl_irq_read_msg()
mei: reduce flow control only for completed messages
mei: reseting -> resetting
mei: fix reading large reposnes
mei: revamp mei_irq_read_client_message function
mei: revamp mei_amthif_irq_read_message
mei: revamp hbm state machine
Revert "drivers/scsi: use module_pcmcia_driver() in pcmcia drivers"
Revert "scsi: pcmcia: nsp_cs: remove module init/exit function prototypes"
scsi: pcmcia: nsp_cs: remove module init/exit function prototypes
mei: wd: fix line over 80 characters
misc: tsl2550: Use dev_pm_ops
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/ABI/testing/sysfs-bus-mei | 7 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/arm/msm/ssbi.txt | 18 | ||||
-rw-r--r-- | Documentation/misc-devices/mei/mei-client-bus.txt | 138 |
3 files changed, 163 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-mei b/Documentation/ABI/testing/sysfs-bus-mei new file mode 100644 index 000000000000..2066f0bbd453 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-mei @@ -0,0 +1,7 @@ +What: /sys/bus/mei/devices/.../modalias +Date: March 2013 +KernelVersion: 3.10 +Contact: Samuel Ortiz <sameo@linux.intel.com> + linux-mei@linux.intel.com +Description: Stores the same MODALIAS value emitted by uevent + Format: mei:<mei device name> diff --git a/Documentation/devicetree/bindings/arm/msm/ssbi.txt b/Documentation/devicetree/bindings/arm/msm/ssbi.txt new file mode 100644 index 000000000000..54fd5ced3401 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/msm/ssbi.txt @@ -0,0 +1,18 @@ +* Qualcomm SSBI + +Some Qualcomm MSM devices contain a point-to-point serial bus used to +communicate with a limited range of devices (mostly power management +chips). + +These require the following properties: + +- compatible: "qcom,ssbi" + +- qcom,controller-type + indicates the SSBI bus variant the controller should use to talk + with the slave device. This should be one of "ssbi", "ssbi2", or + "pmic-arbiter". The type chosen is determined by the attached + slave. + +The slave device should be the single child node of the ssbi device +with a compatible field. diff --git a/Documentation/misc-devices/mei/mei-client-bus.txt b/Documentation/misc-devices/mei/mei-client-bus.txt new file mode 100644 index 000000000000..f83910a8ce76 --- /dev/null +++ b/Documentation/misc-devices/mei/mei-client-bus.txt @@ -0,0 +1,138 @@ +Intel(R) Management Engine (ME) Client bus API +=============================================== + + +Rationale +========= +MEI misc character device is useful for dedicated applications to send and receive +data to the many FW appliance found in Intel's ME from the user space. +However for some of the ME functionalities it make sense to leverage existing software +stack and expose them through existing kernel subsystems. + +In order to plug seamlessly into the kernel device driver model we add kernel virtual +bus abstraction on top of the MEI driver. This allows implementing linux kernel drivers +for the various MEI features as a stand alone entities found in their respective subsystem. +Existing device drivers can even potentially be re-used by adding an MEI CL bus layer to +the existing code. + + +MEI CL bus API +=========== +A driver implementation for an MEI Client is very similar to existing bus +based device drivers. The driver registers itself as an MEI CL bus driver through +the mei_cl_driver structure: + +struct mei_cl_driver { + struct device_driver driver; + const char *name; + + const struct mei_cl_device_id *id_table; + + int (*probe)(struct mei_cl_device *dev, const struct mei_cl_id *id); + int (*remove)(struct mei_cl_device *dev); +}; + +struct mei_cl_id { + char name[MEI_NAME_SIZE]; + kernel_ulong_t driver_info; +}; + +The mei_cl_id structure allows the driver to bind itself against a device name. + +To actually register a driver on the ME Client bus one must call the mei_cl_add_driver() +API. This is typically called at module init time. + +Once registered on the ME Client bus, a driver will typically try to do some I/O on +this bus and this should be done through the mei_cl_send() and mei_cl_recv() +routines. The latter is synchronous (blocks and sleeps until data shows up). +In order for drivers to be notified of pending events waiting for them (e.g. +an Rx event) they can register an event handler through the +mei_cl_register_event_cb() routine. Currently only the MEI_EVENT_RX event +will trigger an event handler call and the driver implementation is supposed +to call mei_recv() from the event handler in order to fetch the pending +received buffers. + + +Example +======= +As a theoretical example let's pretend the ME comes with a "contact" NFC IP. +The driver init and exit routines for this device would look like: + +#define CONTACT_DRIVER_NAME "contact" + +static struct mei_cl_device_id contact_mei_cl_tbl[] = { + { CONTACT_DRIVER_NAME, }, + + /* required last entry */ + { } +}; +MODULE_DEVICE_TABLE(mei_cl, contact_mei_cl_tbl); + +static struct mei_cl_driver contact_driver = { + .id_table = contact_mei_tbl, + .name = CONTACT_DRIVER_NAME, + + .probe = contact_probe, + .remove = contact_remove, +}; + +static int contact_init(void) +{ + int r; + + r = mei_cl_driver_register(&contact_driver); + if (r) { + pr_err(CONTACT_DRIVER_NAME ": driver registration failed\n"); + return r; + } + + return 0; +} + +static void __exit contact_exit(void) +{ + mei_cl_driver_unregister(&contact_driver); +} + +module_init(contact_init); +module_exit(contact_exit); + +And the driver's simplified probe routine would look like that: + +int contact_probe(struct mei_cl_device *dev, struct mei_cl_device_id *id) +{ + struct contact_driver *contact; + + [...] + mei_cl_enable_device(dev); + + mei_cl_register_event_cb(dev, contact_event_cb, contact); + + return 0; + } + +In the probe routine the driver first enable the MEI device and then registers +an ME bus event handler which is as close as it can get to registering a +threaded IRQ handler. +The handler implementation will typically call some I/O routine depending on +the pending events: + +#define MAX_NFC_PAYLOAD 128 + +static void contact_event_cb(struct mei_cl_device *dev, u32 events, + void *context) +{ + struct contact_driver *contact = context; + + if (events & BIT(MEI_EVENT_RX)) { + u8 payload[MAX_NFC_PAYLOAD]; + int payload_size; + + payload_size = mei_recv(dev, payload, MAX_NFC_PAYLOAD); + if (payload_size <= 0) + return; + + /* Hook to the NFC subsystem */ + nfc_hci_recv_frame(contact->hdev, payload, payload_size); + } +} |