[PATCH 4/5] platform/chrome: cros_ec: Add a flag to track registration state
From: Tzung-Bi Shih <tzungbi@kernel.org>
Date: 2025-08-28 08:36:26
Also in:
chrome-platform
Subsystem:
chrome hardware platform support, the rest · Maintainers:
Benson Leung, Tzung-Bi Shih, Linus Torvalds
Introduce a `registered` flag to the `struct cros_ec_device` to allow callers to determine if the device has been fully registered and is ready for use. This is a preparatory step to prevent race conditions where other drivers might try to access the device before it is fully registered or after it has been unregistered. Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org> --- drivers/platform/chrome/cros_ec.c | 7 +++++++ drivers/platform/chrome/cros_ec_proto.c | 15 +++++++++++++++ include/linux/platform_data/cros_ec_proto.h | 4 ++++ 3 files changed, 26 insertions(+)
diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
index 61bcef8741db..1da79e3d215b 100644
--- a/drivers/platform/chrome/cros_ec.c
+++ b/drivers/platform/chrome/cros_ec.c@@ -9,6 +9,7 @@ * battery charging and regulator control, firmware update. */ +#include <linux/cleanup.h> #include <linux/interrupt.h> #include <linux/module.h> #include <linux/of_platform.h>
@@ -316,6 +317,9 @@ int cros_ec_register(struct cros_ec_device *ec_dev) goto exit; } + scoped_guard(mutex, &ec_dev->lock) + ec_dev->registered = true; + dev_info(dev, "Chrome EC device registered\n"); /*
@@ -343,6 +347,9 @@ EXPORT_SYMBOL(cros_ec_register); */ void cros_ec_unregister(struct cros_ec_device *ec_dev) { + scoped_guard(mutex, &ec_dev->lock) + ec_dev->registered = false; + if (ec_dev->mkbp_event_supported) blocking_notifier_chain_unregister(&ec_dev->event_notifier, &ec_dev->notifier_ready);
diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 3e94a0a82173..1d8d9168ec1a 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c@@ -3,6 +3,7 @@ // // Copyright (C) 2015 Google, Inc +#include <linux/cleanup.h> #include <linux/delay.h> #include <linux/device.h> #include <linux/limits.h>
@@ -1153,5 +1154,19 @@ int cros_ec_get_cmd_versions(struct cros_ec_device *ec_dev, u16 cmd) } EXPORT_SYMBOL_GPL(cros_ec_get_cmd_versions); +/** + * cros_ec_device_registered - Return if the ec_dev is registered. + * + * @ec_dev: EC device + * + * Return: true if registered. Otherwise, false. + */ +bool cros_ec_device_registered(struct cros_ec_device *ec_dev) +{ + guard(mutex)(&ec_dev->lock); + return ec_dev->registered; +} +EXPORT_SYMBOL_GPL(cros_ec_device_registered); + MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("ChromeOS EC communication protocol helpers");
diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/platform_data/cros_ec_proto.h
index 4d96cffbb9e3..de14923720a5 100644
--- a/include/linux/platform_data/cros_ec_proto.h
+++ b/include/linux/platform_data/cros_ec_proto.h@@ -128,6 +128,7 @@ struct cros_ec_command { * @dout_size: Size of dout buffer to allocate (zero to use static dout). * @wake_enabled: True if this device can wake the system from sleep. * @suspended: True if this device had been suspended. + * @registered: True if this device had been registered. * @cmd_xfer: Send command to EC and get response. * Returns the number of bytes received if the communication * succeeded, but that doesn't mean the EC was happy with the
@@ -186,6 +187,7 @@ struct cros_ec_device { int dout_size; bool wake_enabled; bool suspended; + bool registered; int (*cmd_xfer)(struct cros_ec_device *ec, struct cros_ec_command *msg); int (*pkt_xfer)(struct cros_ec_device *ec,
@@ -278,6 +280,8 @@ int cros_ec_cmd_readmem(struct cros_ec_device *ec_dev, u8 offset, u8 size, void int cros_ec_get_cmd_versions(struct cros_ec_device *ec_dev, u16 cmd); +bool cros_ec_device_registered(struct cros_ec_device *ec_dev); + /** * cros_ec_get_time_ns() - Return time in ns. *
--
2.51.0.268.g9569e192d0-goog