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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-02-22 08:50:01 -0800 |
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| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-02-22 08:50:01 -0800 |
| commit | 983e4adae0cfa4d3dfdf73b79aabc450dda8ce0e (patch) | |
| tree | addc29bc5cf959ef4eb1258c9722d4afdfaa063e /drivers/platform/surface/surface_aggregator_cdev.c | |
| parent | 31caf8b2a847214be856f843e251fc2ed2cd1075 (diff) | |
| parent | a7d53dbbc70a81d5781da7fc905b656f41ad2381 (diff) | |
| download | linux-983e4adae0cfa4d3dfdf73b79aabc450dda8ce0e.tar.gz linux-983e4adae0cfa4d3dfdf73b79aabc450dda8ce0e.tar.bz2 linux-983e4adae0cfa4d3dfdf73b79aabc450dda8ce0e.zip | |
Merge tag 'platform-drivers-x86-v5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86
Pull x86 platform driver updates from Hans de Goede:
"Highlights:
- Microsoft Surface devices System Aggregator Module support
- SW_TABLET_MODE reporting improvements
- thinkpad_acpi keyboard language setting support
- platform / DPTF profile settings support:
- Base / userspace API parts merged from Rafael's acpi-platform
branch
- thinkpad_acpi and ideapad-laptop support through pdx86
- Remove support for some obsolete Intel MID platforms through
merging of the shared intel-mid-removal branch
- Big cleanup of the ideapad-laptop driver
- Misc other fixes / new hw support / quirks"
* tag 'platform-drivers-x86-v5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (99 commits)
platform/x86: intel_scu_ipc: Increase virtual timeout from 3 to 5 seconds
platform/surface: aggregator: Fix access of unaligned value
tools/power/x86/intel-speed-select: Update version to 1.8
tools/power/x86/intel-speed-select: Add new command to get/set TRL
tools/power/x86/intel-speed-select: Add new command turbo-mode
Platform: OLPC: Constify static struct regulator_ops
platform/surface: Add Surface Hot-Plug driver
platform/x86: intel_scu_wdt: Drop mistakenly added const
platform/x86: Kconfig: add missing selects for ideapad-laptop
platform/x86: acer-wmi: Don't use ACPI_EXCEPTION()
platform/x86: thinkpad_acpi: Replace ifdef CONFIG_ACPI_PLATFORM_PROFILE with depends on
platform/x86: thinkpad_acpi: Fix 'warning: no previous prototype for' warnings
platform/x86: msi-wmi: Fix variable 'status' set but not used compiler warning
platform/surface: surface3-wmi: Fix variable 'status' set but not used compiler warning
platform/x86: Move all dell drivers to their own subdirectory
Documentation/ABI: sysfs-platform-ideapad-laptop: conservation_mode attribute
Documentation/ABI: sysfs-platform-ideapad-laptop: update device attribute paths
platform/x86: ideapad-laptop: add "always on USB charging" control support
platform/x86: ideapad-laptop: add keyboard backlight control support
platform/x86: ideapad-laptop: send notification about touchpad state change to sysfs
...
Diffstat (limited to 'drivers/platform/surface/surface_aggregator_cdev.c')
| -rw-r--r-- | drivers/platform/surface/surface_aggregator_cdev.c | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/drivers/platform/surface/surface_aggregator_cdev.c b/drivers/platform/surface/surface_aggregator_cdev.c new file mode 100644 index 000000000000..79e28fab7e40 --- /dev/null +++ b/drivers/platform/surface/surface_aggregator_cdev.c @@ -0,0 +1,322 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Provides user-space access to the SSAM EC via the /dev/surface/aggregator + * misc device. Intended for debugging and development. + * + * Copyright (C) 2020 Maximilian Luz <luzmaximilian@gmail.com> + */ + +#include <linux/fs.h> +#include <linux/kernel.h> +#include <linux/kref.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/rwsem.h> +#include <linux/slab.h> +#include <linux/uaccess.h> + +#include <linux/surface_aggregator/cdev.h> +#include <linux/surface_aggregator/controller.h> + +#define SSAM_CDEV_DEVICE_NAME "surface_aggregator_cdev" + +struct ssam_cdev { + struct kref kref; + struct rw_semaphore lock; + struct ssam_controller *ctrl; + struct miscdevice mdev; +}; + +static void __ssam_cdev_release(struct kref *kref) +{ + kfree(container_of(kref, struct ssam_cdev, kref)); +} + +static struct ssam_cdev *ssam_cdev_get(struct ssam_cdev *cdev) +{ + if (cdev) + kref_get(&cdev->kref); + + return cdev; +} + +static void ssam_cdev_put(struct ssam_cdev *cdev) +{ + if (cdev) + kref_put(&cdev->kref, __ssam_cdev_release); +} + +static int ssam_cdev_device_open(struct inode *inode, struct file *filp) +{ + struct miscdevice *mdev = filp->private_data; + struct ssam_cdev *cdev = container_of(mdev, struct ssam_cdev, mdev); + + filp->private_data = ssam_cdev_get(cdev); + return stream_open(inode, filp); +} + +static int ssam_cdev_device_release(struct inode *inode, struct file *filp) +{ + ssam_cdev_put(filp->private_data); + return 0; +} + +static long ssam_cdev_request(struct ssam_cdev *cdev, unsigned long arg) +{ + struct ssam_cdev_request __user *r; + struct ssam_cdev_request rqst; + struct ssam_request spec = {}; + struct ssam_response rsp = {}; + const void __user *plddata; + void __user *rspdata; + int status = 0, ret = 0, tmp; + + r = (struct ssam_cdev_request __user *)arg; + ret = copy_struct_from_user(&rqst, sizeof(rqst), r, sizeof(*r)); + if (ret) + goto out; + + plddata = u64_to_user_ptr(rqst.payload.data); + rspdata = u64_to_user_ptr(rqst.response.data); + + /* Setup basic request fields. */ + spec.target_category = rqst.target_category; + spec.target_id = rqst.target_id; + spec.command_id = rqst.command_id; + spec.instance_id = rqst.instance_id; + spec.flags = 0; + spec.length = rqst.payload.length; + spec.payload = NULL; + + if (rqst.flags & SSAM_CDEV_REQUEST_HAS_RESPONSE) + spec.flags |= SSAM_REQUEST_HAS_RESPONSE; + + if (rqst.flags & SSAM_CDEV_REQUEST_UNSEQUENCED) + spec.flags |= SSAM_REQUEST_UNSEQUENCED; + + rsp.capacity = rqst.response.length; + rsp.length = 0; + rsp.pointer = NULL; + + /* Get request payload from user-space. */ + if (spec.length) { + if (!plddata) { + ret = -EINVAL; + goto out; + } + + /* + * Note: spec.length is limited to U16_MAX bytes via struct + * ssam_cdev_request. This is slightly larger than the + * theoretical maximum (SSH_COMMAND_MAX_PAYLOAD_SIZE) of the + * underlying protocol (note that nothing remotely this size + * should ever be allocated in any normal case). This size is + * validated later in ssam_request_sync(), for allocation the + * bound imposed by u16 should be enough. + */ + spec.payload = kzalloc(spec.length, GFP_KERNEL); + if (!spec.payload) { + ret = -ENOMEM; + goto out; + } + + if (copy_from_user((void *)spec.payload, plddata, spec.length)) { + ret = -EFAULT; + goto out; + } + } + + /* Allocate response buffer. */ + if (rsp.capacity) { + if (!rspdata) { + ret = -EINVAL; + goto out; + } + + /* + * Note: rsp.capacity is limited to U16_MAX bytes via struct + * ssam_cdev_request. This is slightly larger than the + * theoretical maximum (SSH_COMMAND_MAX_PAYLOAD_SIZE) of the + * underlying protocol (note that nothing remotely this size + * should ever be allocated in any normal case). In later use, + * this capacity does not have to be strictly bounded, as it + * is only used as an output buffer to be written to. For + * allocation the bound imposed by u16 should be enough. + */ + rsp.pointer = kzalloc(rsp.capacity, GFP_KERNEL); + if (!rsp.pointer) { + ret = -ENOMEM; + goto out; + } + } + + /* Perform request. */ + status = ssam_request_sync(cdev->ctrl, &spec, &rsp); + if (status) + goto out; + + /* Copy response to user-space. */ + if (rsp.length && copy_to_user(rspdata, rsp.pointer, rsp.length)) + ret = -EFAULT; + +out: + /* Always try to set response-length and status. */ + tmp = put_user(rsp.length, &r->response.length); + if (tmp) + ret = tmp; + + tmp = put_user(status, &r->status); + if (tmp) + ret = tmp; + + /* Cleanup. */ + kfree(spec.payload); + kfree(rsp.pointer); + + return ret; +} + +static long __ssam_cdev_device_ioctl(struct ssam_cdev *cdev, unsigned int cmd, + unsigned long arg) +{ + switch (cmd) { + case SSAM_CDEV_REQUEST: + return ssam_cdev_request(cdev, arg); + + default: + return -ENOTTY; + } +} + +static long ssam_cdev_device_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct ssam_cdev *cdev = file->private_data; + long status; + + /* Ensure that controller is valid for as long as we need it. */ + if (down_read_killable(&cdev->lock)) + return -ERESTARTSYS; + + if (!cdev->ctrl) { + up_read(&cdev->lock); + return -ENODEV; + } + + status = __ssam_cdev_device_ioctl(cdev, cmd, arg); + + up_read(&cdev->lock); + return status; +} + +static const struct file_operations ssam_controller_fops = { + .owner = THIS_MODULE, + .open = ssam_cdev_device_open, + .release = ssam_cdev_device_release, + .unlocked_ioctl = ssam_cdev_device_ioctl, + .compat_ioctl = ssam_cdev_device_ioctl, + .llseek = noop_llseek, +}; + +static int ssam_dbg_device_probe(struct platform_device *pdev) +{ + struct ssam_controller *ctrl; + struct ssam_cdev *cdev; + int status; + + ctrl = ssam_client_bind(&pdev->dev); + if (IS_ERR(ctrl)) + return PTR_ERR(ctrl) == -ENODEV ? -EPROBE_DEFER : PTR_ERR(ctrl); + + cdev = kzalloc(sizeof(*cdev), GFP_KERNEL); + if (!cdev) + return -ENOMEM; + + kref_init(&cdev->kref); + init_rwsem(&cdev->lock); + cdev->ctrl = ctrl; + + cdev->mdev.parent = &pdev->dev; + cdev->mdev.minor = MISC_DYNAMIC_MINOR; + cdev->mdev.name = "surface_aggregator"; + cdev->mdev.nodename = "surface/aggregator"; + cdev->mdev.fops = &ssam_controller_fops; + + status = misc_register(&cdev->mdev); + if (status) { + kfree(cdev); + return status; + } + + platform_set_drvdata(pdev, cdev); + return 0; +} + +static int ssam_dbg_device_remove(struct platform_device *pdev) +{ + struct ssam_cdev *cdev = platform_get_drvdata(pdev); + + misc_deregister(&cdev->mdev); + + /* + * The controller is only guaranteed to be valid for as long as the + * driver is bound. Remove controller so that any lingering open files + * cannot access it any more after we're gone. + */ + down_write(&cdev->lock); + cdev->ctrl = NULL; + up_write(&cdev->lock); + + ssam_cdev_put(cdev); + return 0; +} + +static struct platform_device *ssam_cdev_device; + +static struct platform_driver ssam_cdev_driver = { + .probe = ssam_dbg_device_probe, + .remove = ssam_dbg_device_remove, + .driver = { + .name = SSAM_CDEV_DEVICE_NAME, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, +}; + +static int __init ssam_debug_init(void) +{ + int status; + + ssam_cdev_device = platform_device_alloc(SSAM_CDEV_DEVICE_NAME, + PLATFORM_DEVID_NONE); + if (!ssam_cdev_device) + return -ENOMEM; + + status = platform_device_add(ssam_cdev_device); + if (status) + goto err_device; + + status = platform_driver_register(&ssam_cdev_driver); + if (status) + goto err_driver; + + return 0; + +err_driver: + platform_device_del(ssam_cdev_device); +err_device: + platform_device_put(ssam_cdev_device); + return status; +} +module_init(ssam_debug_init); + +static void __exit ssam_debug_exit(void) +{ + platform_driver_unregister(&ssam_cdev_driver); + platform_device_unregister(ssam_cdev_device); +} +module_exit(ssam_debug_exit); + +MODULE_AUTHOR("Maximilian Luz <luzmaximilian@gmail.com>"); +MODULE_DESCRIPTION("User-space interface for Surface System Aggregator Module"); +MODULE_LICENSE("GPL"); |
