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authorJohn W. Linville <linville@tuxdriver.com>2012-05-22 15:18:06 -0400
committerJohn W. Linville <linville@tuxdriver.com>2012-05-22 15:18:06 -0400
commita0d0d1685f9763ab26a394df3ab84026b39a06a7 (patch)
tree4165dc6fd3266977ab4b3fa3b379c47597f97d88 /Documentation
parent31a67102f4762df5544bc2dfb34a931233d2a5b2 (diff)
parent05f8f25276ea8c7d41b3649890d6eaf179e67a81 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/feature-removal-schedule.txt12
-rw-r--r--Documentation/nfc/nfc-hci.txt45
2 files changed, 47 insertions, 10 deletions
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index e4b57756b9f5..04d81d26d5fe 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -534,6 +534,18 @@ Who: Kees Cook <keescook@chromium.org>
----------------------------
+What: Removing the pn544 raw driver.
+When: 3.6
+Why: With the introduction of the NFC HCI and SHDL kernel layers, pn544.c
+ is being replaced by pn544_hci.c which is accessible through the netlink
+ and socket NFC APIs. Moreover, pn544.c is outdated and does not seem to
+ work properly with the latest Android stacks.
+ Having 2 drivers for the same hardware is confusing and as such we
+ should only keep the one following the kernel NFC APIs.
+Who: Samuel Ortiz <sameo@linux.intel.com>
+
+----------------------------
+
What: setitimer accepts user NULL pointer (value)
When: 3.6
Why: setitimer is not returning -EFAULT if user pointer is NULL. This
diff --git a/Documentation/nfc/nfc-hci.txt b/Documentation/nfc/nfc-hci.txt
index 216b7254fcc3..320f9336c781 100644
--- a/Documentation/nfc/nfc-hci.txt
+++ b/Documentation/nfc/nfc-hci.txt
@@ -22,9 +22,9 @@ response to arrive.
HCI events can also be received from the host controller. They will be handled
and a translation will be forwarded to NFC Core as needed.
HCI uses 2 execution contexts:
-- one if for executing commands : nfc_hci_msg_tx_work(). Only one command
+- one for executing commands : nfc_hci_msg_tx_work(). Only one command
can be executing at any given moment.
-- one if for dispatching received events and responses : nfc_hci_msg_rx_work()
+- one for dispatching received events and commands : nfc_hci_msg_rx_work().
HCI Session initialization:
---------------------------
@@ -52,18 +52,42 @@ entry points:
struct nfc_hci_ops {
int (*open)(struct nfc_hci_dev *hdev);
void (*close)(struct nfc_hci_dev *hdev);
+ int (*hci_ready) (struct nfc_hci_dev *hdev);
int (*xmit)(struct nfc_hci_dev *hdev, struct sk_buff *skb);
int (*start_poll)(struct nfc_hci_dev *hdev, u32 protocols);
int (*target_from_gate)(struct nfc_hci_dev *hdev, u8 gate,
struct nfc_target *target);
+ int (*complete_target_discovered) (struct nfc_hci_dev *hdev, u8 gate,
+ struct nfc_target *target);
+ int (*data_exchange) (struct nfc_hci_dev *hdev,
+ struct nfc_target *target,
+ struct sk_buff *skb, struct sk_buff **res_skb);
+ int (*check_presence)(struct nfc_hci_dev *hdev,
+ struct nfc_target *target);
};
-open() and close() shall turn the hardware on and off. xmit() shall simply
-write a frame to the chip. start_poll() is an optional entrypoint that shall
-set the hardware in polling mode. This must be implemented only if the hardware
-uses proprietary gates or a mechanism slightly different from the HCI standard.
-target_from_gate() is another optional entrypoint to return the protocols
+- open() and close() shall turn the hardware on and off.
+- hci_ready() is an optional entry point that is called right after the hci
+session has been set up. The driver can use it to do additional initialization
+that must be performed using HCI commands.
+- xmit() shall simply write a frame to the chip.
+- start_poll() is an optional entrypoint that shall set the hardware in polling
+mode. This must be implemented only if the hardware uses proprietary gates or a
+mechanism slightly different from the HCI standard.
+- target_from_gate() is an optional entrypoint to return the nfc protocols
corresponding to a proprietary gate.
+- complete_target_discovered() is an optional entry point to let the driver
+perform additional proprietary processing necessary to auto activate the
+discovered target.
+- data_exchange() must be implemented by the driver if proprietary HCI commands
+are required to send data to the tag. Some tag types will require custom
+commands, others can be written to using the standard HCI commands. The driver
+can check the tag type and either do proprietary processing, or return 1 to ask
+for standard processing.
+- check_presence() is an optional entry point that will be called regularly
+by the core to check that an activated tag is still in the field. If this is
+not implemented, the core will not be able to push tag_lost events to the user
+space
On the rx path, the driver is responsible to push incoming HCP frames to HCI
using nfc_hci_recv_frame(). HCI will take care of re-aggregation and handling
@@ -99,7 +123,8 @@ fast, cannot sleep. stores incoming frames into an shdlc rx queue
handles shdlc rx & tx queues. Dispatches HCI cmd responses.
- HCI Tx Cmd worker (MSGTXWQ)
-Serialize execution of HCI commands. Complete execution in case of resp timeout.
+Serializes execution of HCI commands. Completes execution in case of response
+timeout.
- HCI Rx worker (MSGRXWQ)
Dispatches incoming HCI commands or events.
@@ -133,11 +158,11 @@ able to complete the command with a timeout error if no response arrive.
SMW context gets scheduled and invokes nfc_shdlc_sm_work(). This function
handles shdlc framing in and out. It uses the driver xmit to send frames and
receives incoming frames in an skb queue filled from the driver IRQ handler.
-SHDLC I(nformation) frames payload are HCP fragments. They are agregated to
+SHDLC I(nformation) frames payload are HCP fragments. They are aggregated to
form complete HCI frames, which can be a response, command, or event.
HCI Responses are dispatched immediately from this context to unblock
-waiting command execution. Reponse processing involves invoking the completion
+waiting command execution. Response processing involves invoking the completion
callback that was provided by nfc_hci_msg_tx_work() when it sent the command.
The completion callback will then wake the syscall context.