This patch series adds a character device interface to remoteproc framework. Currently there is only a sysfs interface which the userspace clients can use. If a usersapce application crashes after booting the remote processor through the sysfs interface the remote processor does not get any indication about the crash. It might still assume that the application is running. For example modem uses remotefs service to data from disk/flash memory. If the remotefs service crashes, modem still keeps on requesting data which might lead to crash on modem. Even if the service is restarted the file handles modem requested previously would become stale. Adding a character device interface makes the remote processor tightly coupled with the user space application. A crash of the application leads to a close on the file descriptors therefore shutting down the remoteproc. Changelog: v4 -> v5: - Addressed comments from Bjorn and Mathieu. - Added cdev_set_parent call to set remoteproc device as parent of cdev. - Fixed error with rproc_major introduced in the last patch. - Fixed implementation for compat calls. With previous implementation 64bit userspace applications failed to perform the ioctl call, returning errno 25, or "Inappropriate ioctl for device." - Removed exit functions from the driver as remoteproc framework is statically compiled. v3 -> v4: - Addressed comments from Mathieu and Arnaud. - Added locks while writing/reading from the automatic-shutdown-on-release bool. - Changed return value when failing to copy to/from userspace. - Changed logic for calling shutdown on release. - Moved around code after the increase of max line length from 80 to 100. - Moved the call adding character device before device_add in rproc_add to add both sysfs and character device interface together. v2 -> v3: - Move booting of remoteproc from open to a write call. - Add ioctl interface for future functionality extension. - Add an ioctl call to default to rproc shutdown on release. v1 -> v2: - Fixed comments from Bjorn and Matthew. Siddharth Gupta (2): remoteproc: Add remoteproc character device interface remoteproc: core: Register the character device interface Documentation/userspace-api/ioctl/ioctl-number.rst | 1 + drivers/remoteproc/Kconfig | 9 ++ drivers/remoteproc/Makefile | 1 + drivers/remoteproc/remoteproc_cdev.c | 124 +++++++++++++++++++++ drivers/remoteproc/remoteproc_core.c | 7 ++ drivers/remoteproc/remoteproc_internal.h | 28 +++++ include/linux/remoteproc.h | 5 + include/uapi/linux/remoteproc_cdev.h | 37 ++++++ 8 files changed, 212 insertions(+) create mode 100644 drivers/remoteproc/remoteproc_cdev.c create mode 100644 include/uapi/linux/remoteproc_cdev.h -- Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
