summaryrefslogtreecommitdiffstats
path: root/Documentation/driver-api/miscellaneous.rst
diff options
context:
space:
mode:
authorHaojie Li <lihaojie@kylinos.cn>2026-08-25 18:08:45 +0800
committerChun-Kuang Hu <chunkuang.hu@kernel.org>2026-09-28 23:20:55 +0000
commitbce7698e2e6565bb765bd0522337f29f5f312624 (patch)
tree0b735b7b4a27369cb4d75d9431b3ee59ce7e5bcc /Documentation/driver-api/miscellaneous.rst
downloadlinux-stable-bce7698e2e6565bb765bd0522337f29f5f312624.tar.gz
linux-stable-bce7698e2e6565bb765bd0522337f29f5f312624.zip
drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform devicegrafted
platform_device_register_data() can fail and return an ERR_PTR, but the return value is used without checking, leading to an invalid pointer being stored in ddp_comp[].dev and passed to component_match_add() and mtk_ddp_comp_init(), which could result in a kernel crash. Add an IS_ERR() check to jump to the error handling path on failure. Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195") Cc: stable@vger.kernel.org Signed-off-by: Haojie Li <lihaojie@kylinos.cn> Reviewed-by: CK Hu <ck.hu@mediatek.com> Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/ Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Diffstat (limited to 'Documentation/driver-api/miscellaneous.rst')
-rw-r--r--Documentation/driver-api/miscellaneous.rst48
1 files changed, 48 insertions, 0 deletions
diff --git a/Documentation/driver-api/miscellaneous.rst b/Documentation/driver-api/miscellaneous.rst
new file mode 100644
index 000000000..4a5104a36
--- /dev/null
+++ b/Documentation/driver-api/miscellaneous.rst
@@ -0,0 +1,48 @@
+Parallel Port Devices
+=====================
+
+.. kernel-doc:: include/linux/parport.h
+ :internal:
+
+.. kernel-doc:: drivers/parport/ieee1284.c
+ :export:
+
+.. kernel-doc:: drivers/parport/share.c
+ :export:
+
+.. kernel-doc:: drivers/parport/daisy.c
+ :internal:
+
+16x50 UART Driver
+=================
+
+.. kernel-doc:: drivers/tty/serial/8250/8250_core.c
+ :export:
+
+See serial/driver.rst for related APIs.
+
+Pulse-Width Modulation (PWM)
+============================
+
+Pulse-width modulation is a modulation technique primarily used to
+control power supplied to electrical devices.
+
+The PWM framework provides an abstraction for providers and consumers of
+PWM signals. A controller that provides one or more PWM signals is
+registered as :c:type:`struct pwm_chip <pwm_chip>`. Providers
+are expected to embed this structure in a driver-specific structure.
+This structure contains fields that describe a particular chip.
+
+A chip exposes one or more PWM signal sources, each of which exposed as
+a :c:type:`struct pwm_device <pwm_device>`. Operations can be
+performed on PWM devices to control the period, duty cycle, polarity and
+active state of the signal.
+
+Note that PWM devices are exclusive resources: they can always only be
+used by one consumer at a time.
+
+.. kernel-doc:: include/linux/pwm.h
+ :internal:
+
+.. kernel-doc:: drivers/pwm/core.c
+ :export: