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authorLinus Torvalds <torvalds@linux-foundation.org>2021-02-24 19:25:37 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2021-02-24 19:25:37 +0100
commite229b429bb4af24d9828758c0c851bb6a4169400 (patch)
tree95e49922f6c68b5f81cbf7a39349cfad42c5a0f1 /Documentation/driver-api
parentMerge tag 'driver-core-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel... (diff)
parentspmi: spmi-pmic-arb: Fix hw_irq overflow (diff)
downloadlinux-e229b429bb4af24d9828758c0c851bb6a4169400.tar.xz
linux-e229b429bb4af24d9828758c0c851bb6a4169400.zip
Merge tag 'char-misc-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH: "Here is the large set of char/misc/whatever driver subsystem updates for 5.12-rc1. Over time it seems like this tree is collecting more and more tiny driver subsystems in one place, making it easier for those maintainers, which is why this is getting larger. Included in here are: - coresight driver updates - habannalabs driver updates - virtual acrn driver addition (proper acks from the x86 maintainers) - broadcom misc driver addition - speakup driver updates - soundwire driver updates - fpga driver updates - amba driver updates - mei driver updates - vfio driver updates - greybus driver updates - nvmeem driver updates - phy driver updates - mhi driver updates - interconnect driver udpates - fsl-mc bus driver updates - random driver fix - some small misc driver updates (rtsx, pvpanic, etc.) All of these have been in linux-next for a while, with the only reported issue being a merge conflict due to the dfl_device_id addition from the fpga subsystem in here" * tag 'char-misc-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (311 commits) spmi: spmi-pmic-arb: Fix hw_irq overflow Documentation: coresight: Add PID tracing description coresight: etm-perf: Support PID tracing for kernel at EL2 coresight: etm-perf: Clarify comment on perf options ACRN: update MAINTAINERS: mailing list is subscribers-only regmap: sdw-mbq: use MODULE_LICENSE("GPL") regmap: sdw: use no_pm routines for SoundWire 1.2 MBQ regmap: sdw: use _no_pm functions in regmap_read/write soundwire: intel: fix possible crash when no device is detected MAINTAINERS: replace my with email with replacements mhi: Fix double dma free uapi: map_to_7segment: Update example in documentation uio: uio_pci_generic: don't fail probe if pdev->irq equals to IRQ_NOTCONNECTED drivers/misc/vmw_vmci: restrict too big queue size in qp_host_alloc_queue firewire: replace tricky statement by two simple ones vme: make remove callback return void firmware: google: make coreboot driver's remove callback return void firmware: xilinx: Use explicit values for all enum values sample/acrn: Introduce a sample of HSM ioctl interface usage virt: acrn: Introduce an interface for Service VM to control vCPU ...
Diffstat (limited to 'Documentation/driver-api')
-rw-r--r--Documentation/driver-api/index.rst1
-rw-r--r--Documentation/driver-api/pti_intel_mid.rst108
2 files changed, 0 insertions, 109 deletions
diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst
index 9ba74e86751b..b0ab367896ab 100644
--- a/Documentation/driver-api/index.rst
+++ b/Documentation/driver-api/index.rst
@@ -94,7 +94,6 @@ available subsections can be seen below.
pps
ptp
phy/index
- pti_intel_mid
pwm
pldmfw/index
rfkill
diff --git a/Documentation/driver-api/pti_intel_mid.rst b/Documentation/driver-api/pti_intel_mid.rst
deleted file mode 100644
index bacc2a4ee89f..000000000000
--- a/Documentation/driver-api/pti_intel_mid.rst
+++ /dev/null
@@ -1,108 +0,0 @@
-.. SPDX-License-Identifier: GPL-2.0
-
-=============
-Intel MID PTI
-=============
-
-The Intel MID PTI project is HW implemented in Intel Atom
-system-on-a-chip designs based on the Parallel Trace
-Interface for MIPI P1149.7 cJTAG standard. The kernel solution
-for this platform involves the following files::
-
- ./include/linux/pti.h
- ./drivers/.../n_tracesink.h
- ./drivers/.../n_tracerouter.c
- ./drivers/.../n_tracesink.c
- ./drivers/.../pti.c
-
-pti.c is the driver that enables various debugging features
-popular on platforms from certain mobile manufacturers.
-n_tracerouter.c and n_tracesink.c allow extra system information to
-be collected and routed to the pti driver, such as trace
-debugging data from a modem. Although n_tracerouter
-and n_tracesink are a part of the complete PTI solution,
-these two line disciplines can work separately from
-pti.c and route any data stream from one /dev/tty node
-to another /dev/tty node via kernel-space. This provides
-a stable, reliable connection that will not break unless
-the user-space application shuts down (plus avoids
-kernel->user->kernel context switch overheads of routing
-data).
-
-An example debugging usage for this driver system:
-
- * Hook /dev/ttyPTI0 to syslogd. Opening this port will also start
- a console device to further capture debugging messages to PTI.
- * Hook /dev/ttyPTI1 to modem debugging data to write to PTI HW.
- This is where n_tracerouter and n_tracesink are used.
- * Hook /dev/pti to a user-level debugging application for writing
- to PTI HW.
- * `Use mipi_` Kernel Driver API in other device drivers for
- debugging to PTI by first requesting a PTI write address via
- mipi_request_masterchannel(1).
-
-Below is example pseudo-code on how a 'privileged' application
-can hook up n_tracerouter and n_tracesink to any tty on
-a system. 'Privileged' means the application has enough
-privileges to successfully manipulate the ldisc drivers
-but is not just blindly executing as 'root'. Keep in mind
-the use of ioctl(,TIOCSETD,) is not specific to the n_tracerouter
-and n_tracesink line discpline drivers but is a generic
-operation for a program to use a line discpline driver
-on a tty port other than the default n_tty:
-
-.. code-block:: c
-
- /////////// To hook up n_tracerouter and n_tracesink /////////
-
- // Note that n_tracerouter depends on n_tracesink.
- #include <errno.h>
- #define ONE_TTY "/dev/ttyOne"
- #define TWO_TTY "/dev/ttyTwo"
-
- // needed global to hand onto ldisc connection
- static int g_fd_source = -1;
- static int g_fd_sink = -1;
-
- // these two vars used to grab LDISC values from loaded ldisc drivers
- // in OS. Look at /proc/tty/ldiscs to get the right numbers from
- // the ldiscs loaded in the system.
- int source_ldisc_num, sink_ldisc_num = -1;
- int retval;
-
- g_fd_source = open(ONE_TTY, O_RDWR); // must be R/W
- g_fd_sink = open(TWO_TTY, O_RDWR); // must be R/W
-
- if (g_fd_source <= 0) || (g_fd_sink <= 0) {
- // doubt you'll want to use these exact error lines of code
- printf("Error on open(). errno: %d\n",errno);
- return errno;
- }
-
- retval = ioctl(g_fd_sink, TIOCSETD, &sink_ldisc_num);
- if (retval < 0) {
- printf("Error on ioctl(). errno: %d\n", errno);
- return errno;
- }
-
- retval = ioctl(g_fd_source, TIOCSETD, &source_ldisc_num);
- if (retval < 0) {
- printf("Error on ioctl(). errno: %d\n", errno);
- return errno;
- }
-
- /////////// To disconnect n_tracerouter and n_tracesink ////////
-
- // First make sure data through the ldiscs has stopped.
-
- // Second, disconnect ldiscs. This provides a
- // little cleaner shutdown on tty stack.
- sink_ldisc_num = 0;
- source_ldisc_num = 0;
- ioctl(g_fd_uart, TIOCSETD, &sink_ldisc_num);
- ioctl(g_fd_gadget, TIOCSETD, &source_ldisc_num);
-
- // Three, program closes connection, and cleanup:
- close(g_fd_uart);
- close(g_fd_gadget);
- g_fd_uart = g_fd_gadget = NULL;